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000
FXUS62 KCHS 290802
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
402 AM EDT SUN MAR 29 2015

.SYNOPSIS...
COLD HIGH PRESSURE WILL PREVAIL TODAY...THEN SHIFTS INTO THE
ATLANTIC TONIGHT. WEAK COLD FRONTS WILL PUSH INTO THE REGION LATE
MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER
OR CLOSE TO THE AREA. ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER
THE REGION THROUGH LATE WEEK.  A STRONGER COLD FRONT WILL ARRIVE
FROM THE NORTHWEST NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...THE DEW POINT FRONT WILL CONTINUE TO SWEEP
SOUTHWARD AND CLEAR THE ENTIRE AREA BEFORE SUNRISE. BEHIND THIS
FEATURE IS A LARGE AND COLD ARCTIC HIGH THAT WILL CONTINUE TO FEED
AN INFLUX OF COLDER AIR INTO THE REGION FROM THE NORTH. THIS WILL
ALLOW FOR TEMPS TO FALL BELOW FREEZING FOR 2-4 HOURS ALONG OUR NW
TIER...WHERE THE FREEZE WARNING REMAINS IN EFFECT. THIS WILL ALSO
ALLOW FOR NEAR RECORD COLD AS SHOWN IN THE CLIMATE SECTION BELOW.
THIS TRANSITION HAS ALSO CAUSED MIXING TO INCREASE AS THE COLDER AIR
CONTINUES ITS PENETRATION SOUTHWARD. THIS WILL RESULT IN NORTH/NE
WINDS APPROACHING LAKE WIND ADVISORY CONDITIONS ON LAKE
MOULTRIE...WHERE WE HAVE WINDS OF 15-20 KT AND WAVES 1-2 FT.

FOR THE BULK OF TODAY...WITH THE ARRIVAL OF A FRESHER CANADIAN AIR
MASS THERE ISN/T MUCH MODIFICATION THAT IS ABLE TO OCCUR. ALTHOUGH
COLD ADVECTION THIS MORNING WILL SHUT OFF AND BECOME NEUTRAL OR
EVEN SHOW SLIGHT WARM ADVECTION FOR THIS AFTERNOON. THE FULL
INSOLATION UNDERNEATH THE SURFACE HIGH AS IT SLIDES DIRECTLY
OVERHEAD WILL ALLOW FOR A LARGE DIURNAL SWING IN TEMPS...SOME
20-30F...LEADING TO MAX TEMPS SIMILAR TO YESTERDAY. ONSHORE
TRAJECTORIES WILL HOLD SHORELINE COMMUNITIES SEVERAL DEGREES
COOLER THAN THOSE INLAND.

TONIGHT...THE SURFACE HIGH IS JUST STARTING TO MOVE INTO THE
ATLANTIC THIS EVENING...AND THE GRADIENT IS RATHER NEBULOUS. THIS
WILL ALLOW FOR RAPID DECOUPLING AND EXCELLENT RADIATIONAL COOLING
WILL TRANSPIRE...CAUSING TEMPS TO PLUMMET QUICKLY INTO THE UPPER
30S AND LOWER 40S INLAND WELL BEFORE MIDNIGHT. WE/LL EXPERIENCE A
GOOD 5-8 HOURS OF RADIATIONAL COOLING NORTH AND UP TO 8-10 HOURS
SOUTH. WHILE IT WON/T BE AS COLD AS THIS MORNING...MANY SECTIONS
INLAND WILL FALL INTO THE MIDDLE 30S. THIS COMBINED WITH SMALL
DEW POINT DEPRESSIONS WILL LEAD TO AT LEAST SCATTERED FROST
ACROSS MUCH THE REGION INLAND FROM US-17. AS SUCH WE/LL MOST
LIKELY NEED TO ISSUE A FROST ADVISORY AT SOME POINT LATER TODAY.
FOR LATE TONIGHT OUR TEMPS WILL STEADY OFF OR EVEN RISE AS THE
SYNOPTIC FLOW VEERS AROUND TO THE SOUTH/SW AND WARM ADVECTION
TAKES HOLD AS A LOW LEVEL JET MOVES INTO THE AREA. CLEAR SKIES
EARLY ON WILL GIVE WAY TO SOME MID/HIGH LEVEL CLOUDS ARRIVING FROM
THE WEST/NW LATE IN ADVANCE OF THE NEXT COLD FRONT THAT WILL BE
NEARING THE APPALACHIANS BY SUNRISE.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MONDAY...A PREFRONTAL BAND OF MOISTURE...MAINLY SUPPORTED BY AN 850
MB WESTERLY JET AND ASSOCIATED CONVERGENCE/MOISTURE TRANSPORT...WILL
TRANSLATE QUICKLY TOWARD THE SOUTH/ SOUTHEAST AND THROUGH THE
FORECAST AREA. THIS FORCING SHOULD WEAKEN WITH TIME...AND THE AXIS
OF ENHANCED 850-500 MB RELATIVE HUMIDITY SHOULD BECOME LESS WELL-
DEFINED WITH TIME. GIVEN THE PERSISTENT CAP DEPICTED BY MODEL
SOUNDINGS AND THE GENERAL WEAKENING TRENDS EVIDENT IN
FORCING/ASSOCIATED MOISTURE FIELDS...CAPPED MAXIMUM POPS AT 30-40
PERCENT LATE MORNING INTO MONDAY AFTERNOON. MEANWHILE...ADJUSTED
TIMING OF TO FAVOR A FASTER TREND FAVORED BY ALL OPERATIONAL
GUIDANCE EXCEPT THE 29/00 UTC NAM. ALSO OF NOTE...A NARROW AXIS OF
SURFACE BASED INSTABILITY WILL ATTEMPT TO SPREAD EAST ESPECIALLY
MONDAY AFTERNOON...THUS A MENTION OF THUNDER REMAINS JUSTIFIED
ACROSS MAINLY SOUTHERN COUNTIES.

MONDAY AFTERNOON TEMPERATURES ARE FORECAST TO RANGE FROM THE MID 60S
FAR NORTH TO THE MID 70S FAR SOUTH. HOWEVER...IF CLOUDS/
PRECIPITATION REMAIN LESS PROMINENT THAN EXPECTED...INCREASING W/SW
WINDS COULD PUSH TEMPERATURES WELL INTO THE 70S ACROSS A WIDER SWATH
OF THE FORECAST AREA.

MONDAY NIGHT...THE PROGRESS OF THE AFOREMENTIONED/WEAKENING BAND OF
MOISTURE WILL BECOME PARALLEL TO THE UPPER FLOW AND WILL SLOW
SOUTHWARD PROGRESS...WHILE A WEAK SURFACE COLD FRONT WILL ADVANCE
INTO THE FORECAST AREA FROM THE NORTH. WHILE THE 29/00 UTC NAM IS
LIKELY OVERDONE DEPICTING A RATHER ACTIVE CONVECTIVE REGIME
ALONG/SOUTH OF I-16...A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS IS
STILL JUSTIFIED IN THIS AREA MONDAY EVENING. AFTER MIDNIGHT...POPS
ACROSS THE SOUTH TAPER TO LESS THAN 15 PERCENT WITH NO MENTION OF
PRECIPITATION. OTHERWISE...LOWS IN THE 40S/50S WILL BE COMMON
MONDAY NIGHT.

TUESDAY THROUGH WEDNESDAY...AN INITIAL COLD FRONT WILL STALL AND
DISSIPATE OVER THE REGION TUESDAY...THEN ANOTHER WEAK SURFACE COLD
FRONT WILL PUSH INTO THE AREA FROM THE NORTH WEDNESDAY. THIS SECOND
FRONT WILL ALSO STALL AND DISSIPATE OVER OR PERHAPS JUST SOUTH OF
THE REGION. MEANWHILE...A PLUME OF DEEP-LAYERED MOISTURE WILL RESIDE
JUST SOUTH AND WEST OF THE FORECAST AREA...AND THIS MOISTURE WILL
ATTEMPT TO RIDE THE WEST/NORTHWEST STEERING FLOW TOWARD THE
SOUTHEAST COAST. MODEL SOUNDINGS REMAIN SUFFICIENTLY DRY TO MAINTAIN
RAIN-FREE FORECASTS THROUGH TUESDAY NIGHT...BUT AT LEAST SLIGHT
CHANCE POPS INCLUDING A MENTION OF THUNDER ARE WARRANTED ACROSS
SOUTHERN COUNTIES WEDNESDAY. FORECAST CONFIDENCE REGARDING POPS
DURING THIS PERIOD ARE NOT HIGH...AS PRECIPITATION COULD EITHER
STREAM MORE QUICKLY INTO THE REGION LATE TUESDAY/TUESDAY NIGHT OR
COULD BE HELD MAINLY WEST OF THE REGION AS A SHORTWAVE RIDGE BUILDS
INTO THE REGION WEDNESDAY. OTHERWISE...NORMAL TO SLIGHTLY ABOVE
NORMAL HIGH TEMPERATURES IN THE 70S WILL BE COMMON BOTH DAYS...AND
NIGHTTIME LOWS MAINLY IN THE 50S CAN BE EXPECTED.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL
THEN...NORMAL TO BELOW-NORMAL TEMPERATURES SHOULD RETURN NEXT
WEEKEND.

AS AN UPPER SHORTWAVE TROUGH EJECTS EAST/NORTHEAST ACROSS THE
REGION...AT LEAST CHANCE POPS FOR SHOWERS AND THUNDERSTORMS ARE
JUSTIFIED ESPECIALLY THURSDAY. BETWEEN THE DEPARTING SHORTWAVE AND
AN APPROACHING COLD FRONT...FRIDAY COULD TURN OUT TO BE A VERY WARM
DAY WITH HIGHS IN THE 80S AND POPS BELOW 15 PERCENT WITH NO MENTION
OF PRECIPITATION. A STRONGER COLD FRONT WILL ARRIVE FRIDAY NIGHT OR
SATURDAY. TIMING REMAINS UNCERTAIN...BUT CHANCE POPS AND A MENTION
THUNDERSTORMS ARE CENTERED ON SATURDAY. DRIER AND COOLER CONDITIONS
ARE THEN EXPECTED SUNDAY.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS THIS MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...MAINLY VFR.

&&

.MARINE...
THIS MORNING...A SOLID NORTH/NE SURGE OF WINDS WILL OVERSPREAD THE
MARINE DISTRICT IN RESPONSE TO A 1030 MB HIGH BUILDING OUT OF THE
VIRGINIAS. THE ENSUING COLD ADVECTION AND ISALLOBARIC PRESSURE
RISES OF CLOSE TO 1 MB/HOUR THROUGH MID TO LATE MORNING WILL BUMP
WINDS UP TO 15 OR 20 KT EVERYWHERE. BUT THE GRADIENT WILL BE
GREATEST ON THE CHARLESTON COUNTY ATLANTIC WATERS...AND IT IS HERE
WHERE WE HAVE HOISTED A SMALL CRAFT ADVISORY THROUGH MIDDAY FOR
FREQUENT GUSTS OF 25 KT. THE OTHER WATERS WILL BE CLOSE TO
ADVISORY CONDITIONS...BUT AT PRESENT THEY LOOK TO REMAIN JUST
BELOW THE CRITERIA.

THIS AFTERNOON...RAPID IMPROVEMENT WILL OCCUR AS THE COLD
ADVECTION HALTS...PRESSURE RISES STOP AND THE CORE OF THE
CONTINENTAL HIGH SHIFTS ALMOST DIRECTLY OVERHEAD. WINDS WILL CLOCK
AROUND TO THE EAST AND DIMINISH TO 10 KT OR LESS AS SEAS ALSO FALL.

TONIGHT...WE/LL START THE NIGHT UNDERNEATH THE OFFSHORE
TRANSITIONING HIGH...RESULTING IN VERY LITTLE WIND AND LIMITED
SEAS. BUT THE HIGH DOES SLIDE SE OVERNIGHT IN ADVANCE OF THE
UPSTREAM COLD FRONT MOVING THROUGH THE OHIO/TENNESSEE VALLEYS.
THIS ALONG WITH A DECENT NOCTURNAL LOW LEVEL JET AFTER 06Z WILL
ALLOW FOR SOUTH/SW WINDS TO CLIMB AS HIGH AS 10 OR 15 KT AS SEAS
RISE MAYBE A FOOT.

MONDAY THROUGH FRIDAY...A SURGE OF SOUTHWEST WINDS IS EXPECTED AHEAD
OF AN APPROACHING COLD FRONT MONDAY. HOWEVER...GIVEN THE STABLE
MARINE ENVIRONMENT...HELD WINDS/SEAS BELOW SCA LEVELS. THE COLD
FRONT SHOULD ARRIVE FROM THE NORTH MONDAY NIGHT INTO EARLY
TUESDAY...PERHAPS ACCOMPANIED BY A MODEST SURGE OF NORTHEAST
WINDS...BUT THE PROBABILITY FOR ANY SCA CONDITIONS REMAINS VERY
LOW. THE FRONT WILL STALL AND DISSIPATE...GIVING WAY TO A WEAK
PRESSURE PATTERN TUESDAY AFTERNOON/NIGHT. ANOTHER COLD FRONT WILL
ARRIVE FROM THE NORTH WEDNESDAY...AND THIS FRONT SHOULD ALSO STALL
AND DISSIPATE OVER OR JUST SOUTH OF THE WATERS BY THURSDAY.
SOUTH/SOUTHWEST WINDS SHOULD AGAIN INCREASE AHEAD OF A STRONGER COLD
FRONT APPROACHING FROM THE NORTHWEST LATE THIS WEEK...BUT ONCE AGAIN
MARINE LAYER STABILITY COULD PREVENT SCA WINDS/SEAS.

ALSO OF NOTE...INCREASING DEWPOINTS COULD SUPPORT SOME SEA FOG OVER
NEAR SHORE WATERS ESPECIALLY THURSDAY UNTIL A COLD FROPA OCCURS
FRIDAY NIGHT OR SATURDAY. WILL CONTINUE TO ASSESS.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290802
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
402 AM EDT SUN MAR 29 2015

.SYNOPSIS...
COLD HIGH PRESSURE WILL PREVAIL TODAY...THEN SHIFTS INTO THE
ATLANTIC TONIGHT. WEAK COLD FRONTS WILL PUSH INTO THE REGION LATE
MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER
OR CLOSE TO THE AREA. ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER
THE REGION THROUGH LATE WEEK.  A STRONGER COLD FRONT WILL ARRIVE
FROM THE NORTHWEST NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...THE DEW POINT FRONT WILL CONTINUE TO SWEEP
SOUTHWARD AND CLEAR THE ENTIRE AREA BEFORE SUNRISE. BEHIND THIS
FEATURE IS A LARGE AND COLD ARCTIC HIGH THAT WILL CONTINUE TO FEED
AN INFLUX OF COLDER AIR INTO THE REGION FROM THE NORTH. THIS WILL
ALLOW FOR TEMPS TO FALL BELOW FREEZING FOR 2-4 HOURS ALONG OUR NW
TIER...WHERE THE FREEZE WARNING REMAINS IN EFFECT. THIS WILL ALSO
ALLOW FOR NEAR RECORD COLD AS SHOWN IN THE CLIMATE SECTION BELOW.
THIS TRANSITION HAS ALSO CAUSED MIXING TO INCREASE AS THE COLDER AIR
CONTINUES ITS PENETRATION SOUTHWARD. THIS WILL RESULT IN NORTH/NE
WINDS APPROACHING LAKE WIND ADVISORY CONDITIONS ON LAKE
MOULTRIE...WHERE WE HAVE WINDS OF 15-20 KT AND WAVES 1-2 FT.

FOR THE BULK OF TODAY...WITH THE ARRIVAL OF A FRESHER CANADIAN AIR
MASS THERE ISN/T MUCH MODIFICATION THAT IS ABLE TO OCCUR. ALTHOUGH
COLD ADVECTION THIS MORNING WILL SHUT OFF AND BECOME NEUTRAL OR
EVEN SHOW SLIGHT WARM ADVECTION FOR THIS AFTERNOON. THE FULL
INSOLATION UNDERNEATH THE SURFACE HIGH AS IT SLIDES DIRECTLY
OVERHEAD WILL ALLOW FOR A LARGE DIURNAL SWING IN TEMPS...SOME
20-30F...LEADING TO MAX TEMPS SIMILAR TO YESTERDAY. ONSHORE
TRAJECTORIES WILL HOLD SHORELINE COMMUNITIES SEVERAL DEGREES
COOLER THAN THOSE INLAND.

TONIGHT...THE SURFACE HIGH IS JUST STARTING TO MOVE INTO THE
ATLANTIC THIS EVENING...AND THE GRADIENT IS RATHER NEBULOUS. THIS
WILL ALLOW FOR RAPID DECOUPLING AND EXCELLENT RADIATIONAL COOLING
WILL TRANSPIRE...CAUSING TEMPS TO PLUMMET QUICKLY INTO THE UPPER
30S AND LOWER 40S INLAND WELL BEFORE MIDNIGHT. WE/LL EXPERIENCE A
GOOD 5-8 HOURS OF RADIATIONAL COOLING NORTH AND UP TO 8-10 HOURS
SOUTH. WHILE IT WON/T BE AS COLD AS THIS MORNING...MANY SECTIONS
INLAND WILL FALL INTO THE MIDDLE 30S. THIS COMBINED WITH SMALL
DEW POINT DEPRESSIONS WILL LEAD TO AT LEAST SCATTERED FROST
ACROSS MUCH THE REGION INLAND FROM US-17. AS SUCH WE/LL MOST
LIKELY NEED TO ISSUE A FROST ADVISORY AT SOME POINT LATER TODAY.
FOR LATE TONIGHT OUR TEMPS WILL STEADY OFF OR EVEN RISE AS THE
SYNOPTIC FLOW VEERS AROUND TO THE SOUTH/SW AND WARM ADVECTION
TAKES HOLD AS A LOW LEVEL JET MOVES INTO THE AREA. CLEAR SKIES
EARLY ON WILL GIVE WAY TO SOME MID/HIGH LEVEL CLOUDS ARRIVING FROM
THE WEST/NW LATE IN ADVANCE OF THE NEXT COLD FRONT THAT WILL BE
NEARING THE APPALACHIANS BY SUNRISE.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MONDAY...A PREFRONTAL BAND OF MOISTURE...MAINLY SUPPORTED BY AN 850
MB WESTERLY JET AND ASSOCIATED CONVERGENCE/MOISTURE TRANSPORT...WILL
TRANSLATE QUICKLY TOWARD THE SOUTH/ SOUTHEAST AND THROUGH THE
FORECAST AREA. THIS FORCING SHOULD WEAKEN WITH TIME...AND THE AXIS
OF ENHANCED 850-500 MB RELATIVE HUMIDITY SHOULD BECOME LESS WELL-
DEFINED WITH TIME. GIVEN THE PERSISTENT CAP DEPICTED BY MODEL
SOUNDINGS AND THE GENERAL WEAKENING TRENDS EVIDENT IN
FORCING/ASSOCIATED MOISTURE FIELDS...CAPPED MAXIMUM POPS AT 30-40
PERCENT LATE MORNING INTO MONDAY AFTERNOON. MEANWHILE...ADJUSTED
TIMING OF TO FAVOR A FASTER TREND FAVORED BY ALL OPERATIONAL
GUIDANCE EXCEPT THE 29/00 UTC NAM. ALSO OF NOTE...A NARROW AXIS OF
SURFACE BASED INSTABILITY WILL ATTEMPT TO SPREAD EAST ESPECIALLY
MONDAY AFTERNOON...THUS A MENTION OF THUNDER REMAINS JUSTIFIED
ACROSS MAINLY SOUTHERN COUNTIES.

MONDAY AFTERNOON TEMPERATURES ARE FORECAST TO RANGE FROM THE MID 60S
FAR NORTH TO THE MID 70S FAR SOUTH. HOWEVER...IF CLOUDS/
PRECIPITATION REMAIN LESS PROMINENT THAN EXPECTED...INCREASING W/SW
WINDS COULD PUSH TEMPERATURES WELL INTO THE 70S ACROSS A WIDER SWATH
OF THE FORECAST AREA.

MONDAY NIGHT...THE PROGRESS OF THE AFOREMENTIONED/WEAKENING BAND OF
MOISTURE WILL BECOME PARALLEL TO THE UPPER FLOW AND WILL SLOW
SOUTHWARD PROGRESS...WHILE A WEAK SURFACE COLD FRONT WILL ADVANCE
INTO THE FORECAST AREA FROM THE NORTH. WHILE THE 29/00 UTC NAM IS
LIKELY OVERDONE DEPICTING A RATHER ACTIVE CONVECTIVE REGIME
ALONG/SOUTH OF I-16...A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS IS
STILL JUSTIFIED IN THIS AREA MONDAY EVENING. AFTER MIDNIGHT...POPS
ACROSS THE SOUTH TAPER TO LESS THAN 15 PERCENT WITH NO MENTION OF
PRECIPITATION. OTHERWISE...LOWS IN THE 40S/50S WILL BE COMMON
MONDAY NIGHT.

TUESDAY THROUGH WEDNESDAY...AN INITIAL COLD FRONT WILL STALL AND
DISSIPATE OVER THE REGION TUESDAY...THEN ANOTHER WEAK SURFACE COLD
FRONT WILL PUSH INTO THE AREA FROM THE NORTH WEDNESDAY. THIS SECOND
FRONT WILL ALSO STALL AND DISSIPATE OVER OR PERHAPS JUST SOUTH OF
THE REGION. MEANWHILE...A PLUME OF DEEP-LAYERED MOISTURE WILL RESIDE
JUST SOUTH AND WEST OF THE FORECAST AREA...AND THIS MOISTURE WILL
ATTEMPT TO RIDE THE WEST/NORTHWEST STEERING FLOW TOWARD THE
SOUTHEAST COAST. MODEL SOUNDINGS REMAIN SUFFICIENTLY DRY TO MAINTAIN
RAIN-FREE FORECASTS THROUGH TUESDAY NIGHT...BUT AT LEAST SLIGHT
CHANCE POPS INCLUDING A MENTION OF THUNDER ARE WARRANTED ACROSS
SOUTHERN COUNTIES WEDNESDAY. FORECAST CONFIDENCE REGARDING POPS
DURING THIS PERIOD ARE NOT HIGH...AS PRECIPITATION COULD EITHER
STREAM MORE QUICKLY INTO THE REGION LATE TUESDAY/TUESDAY NIGHT OR
COULD BE HELD MAINLY WEST OF THE REGION AS A SHORTWAVE RIDGE BUILDS
INTO THE REGION WEDNESDAY. OTHERWISE...NORMAL TO SLIGHTLY ABOVE
NORMAL HIGH TEMPERATURES IN THE 70S WILL BE COMMON BOTH DAYS...AND
NIGHTTIME LOWS MAINLY IN THE 50S CAN BE EXPECTED.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL
THEN...NORMAL TO BELOW-NORMAL TEMPERATURES SHOULD RETURN NEXT
WEEKEND.

AS AN UPPER SHORTWAVE TROUGH EJECTS EAST/NORTHEAST ACROSS THE
REGION...AT LEAST CHANCE POPS FOR SHOWERS AND THUNDERSTORMS ARE
JUSTIFIED ESPECIALLY THURSDAY. BETWEEN THE DEPARTING SHORTWAVE AND
AN APPROACHING COLD FRONT...FRIDAY COULD TURN OUT TO BE A VERY WARM
DAY WITH HIGHS IN THE 80S AND POPS BELOW 15 PERCENT WITH NO MENTION
OF PRECIPITATION. A STRONGER COLD FRONT WILL ARRIVE FRIDAY NIGHT OR
SATURDAY. TIMING REMAINS UNCERTAIN...BUT CHANCE POPS AND A MENTION
THUNDERSTORMS ARE CENTERED ON SATURDAY. DRIER AND COOLER CONDITIONS
ARE THEN EXPECTED SUNDAY.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS THIS MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...MAINLY VFR.

&&

.MARINE...
THIS MORNING...A SOLID NORTH/NE SURGE OF WINDS WILL OVERSPREAD THE
MARINE DISTRICT IN RESPONSE TO A 1030 MB HIGH BUILDING OUT OF THE
VIRGINIAS. THE ENSUING COLD ADVECTION AND ISALLOBARIC PRESSURE
RISES OF CLOSE TO 1 MB/HOUR THROUGH MID TO LATE MORNING WILL BUMP
WINDS UP TO 15 OR 20 KT EVERYWHERE. BUT THE GRADIENT WILL BE
GREATEST ON THE CHARLESTON COUNTY ATLANTIC WATERS...AND IT IS HERE
WHERE WE HAVE HOISTED A SMALL CRAFT ADVISORY THROUGH MIDDAY FOR
FREQUENT GUSTS OF 25 KT. THE OTHER WATERS WILL BE CLOSE TO
ADVISORY CONDITIONS...BUT AT PRESENT THEY LOOK TO REMAIN JUST
BELOW THE CRITERIA.

THIS AFTERNOON...RAPID IMPROVEMENT WILL OCCUR AS THE COLD
ADVECTION HALTS...PRESSURE RISES STOP AND THE CORE OF THE
CONTINENTAL HIGH SHIFTS ALMOST DIRECTLY OVERHEAD. WINDS WILL CLOCK
AROUND TO THE EAST AND DIMINISH TO 10 KT OR LESS AS SEAS ALSO FALL.

TONIGHT...WE/LL START THE NIGHT UNDERNEATH THE OFFSHORE
TRANSITIONING HIGH...RESULTING IN VERY LITTLE WIND AND LIMITED
SEAS. BUT THE HIGH DOES SLIDE SE OVERNIGHT IN ADVANCE OF THE
UPSTREAM COLD FRONT MOVING THROUGH THE OHIO/TENNESSEE VALLEYS.
THIS ALONG WITH A DECENT NOCTURNAL LOW LEVEL JET AFTER 06Z WILL
ALLOW FOR SOUTH/SW WINDS TO CLIMB AS HIGH AS 10 OR 15 KT AS SEAS
RISE MAYBE A FOOT.

MONDAY THROUGH FRIDAY...A SURGE OF SOUTHWEST WINDS IS EXPECTED AHEAD
OF AN APPROACHING COLD FRONT MONDAY. HOWEVER...GIVEN THE STABLE
MARINE ENVIRONMENT...HELD WINDS/SEAS BELOW SCA LEVELS. THE COLD
FRONT SHOULD ARRIVE FROM THE NORTH MONDAY NIGHT INTO EARLY
TUESDAY...PERHAPS ACCOMPANIED BY A MODEST SURGE OF NORTHEAST
WINDS...BUT THE PROBABILITY FOR ANY SCA CONDITIONS REMAINS VERY
LOW. THE FRONT WILL STALL AND DISSIPATE...GIVING WAY TO A WEAK
PRESSURE PATTERN TUESDAY AFTERNOON/NIGHT. ANOTHER COLD FRONT WILL
ARRIVE FROM THE NORTH WEDNESDAY...AND THIS FRONT SHOULD ALSO STALL
AND DISSIPATE OVER OR JUST SOUTH OF THE WATERS BY THURSDAY.
SOUTH/SOUTHWEST WINDS SHOULD AGAIN INCREASE AHEAD OF A STRONGER COLD
FRONT APPROACHING FROM THE NORTHWEST LATE THIS WEEK...BUT ONCE AGAIN
MARINE LAYER STABILITY COULD PREVENT SCA WINDS/SEAS.

ALSO OF NOTE...INCREASING DEWPOINTS COULD SUPPORT SOME SEA FOG OVER
NEAR SHORE WATERS ESPECIALLY THURSDAY UNTIL A COLD FROPA OCCURS
FRIDAY NIGHT OR SATURDAY. WILL CONTINUE TO ASSESS.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290802
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
402 AM EDT SUN MAR 29 2015

.SYNOPSIS...
COLD HIGH PRESSURE WILL PREVAIL TODAY...THEN SHIFTS INTO THE
ATLANTIC TONIGHT. WEAK COLD FRONTS WILL PUSH INTO THE REGION LATE
MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER
OR CLOSE TO THE AREA. ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER
THE REGION THROUGH LATE WEEK.  A STRONGER COLD FRONT WILL ARRIVE
FROM THE NORTHWEST NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...THE DEW POINT FRONT WILL CONTINUE TO SWEEP
SOUTHWARD AND CLEAR THE ENTIRE AREA BEFORE SUNRISE. BEHIND THIS
FEATURE IS A LARGE AND COLD ARCTIC HIGH THAT WILL CONTINUE TO FEED
AN INFLUX OF COLDER AIR INTO THE REGION FROM THE NORTH. THIS WILL
ALLOW FOR TEMPS TO FALL BELOW FREEZING FOR 2-4 HOURS ALONG OUR NW
TIER...WHERE THE FREEZE WARNING REMAINS IN EFFECT. THIS WILL ALSO
ALLOW FOR NEAR RECORD COLD AS SHOWN IN THE CLIMATE SECTION BELOW.
THIS TRANSITION HAS ALSO CAUSED MIXING TO INCREASE AS THE COLDER AIR
CONTINUES ITS PENETRATION SOUTHWARD. THIS WILL RESULT IN NORTH/NE
WINDS APPROACHING LAKE WIND ADVISORY CONDITIONS ON LAKE
MOULTRIE...WHERE WE HAVE WINDS OF 15-20 KT AND WAVES 1-2 FT.

FOR THE BULK OF TODAY...WITH THE ARRIVAL OF A FRESHER CANADIAN AIR
MASS THERE ISN/T MUCH MODIFICATION THAT IS ABLE TO OCCUR. ALTHOUGH
COLD ADVECTION THIS MORNING WILL SHUT OFF AND BECOME NEUTRAL OR
EVEN SHOW SLIGHT WARM ADVECTION FOR THIS AFTERNOON. THE FULL
INSOLATION UNDERNEATH THE SURFACE HIGH AS IT SLIDES DIRECTLY
OVERHEAD WILL ALLOW FOR A LARGE DIURNAL SWING IN TEMPS...SOME
20-30F...LEADING TO MAX TEMPS SIMILAR TO YESTERDAY. ONSHORE
TRAJECTORIES WILL HOLD SHORELINE COMMUNITIES SEVERAL DEGREES
COOLER THAN THOSE INLAND.

TONIGHT...THE SURFACE HIGH IS JUST STARTING TO MOVE INTO THE
ATLANTIC THIS EVENING...AND THE GRADIENT IS RATHER NEBULOUS. THIS
WILL ALLOW FOR RAPID DECOUPLING AND EXCELLENT RADIATIONAL COOLING
WILL TRANSPIRE...CAUSING TEMPS TO PLUMMET QUICKLY INTO THE UPPER
30S AND LOWER 40S INLAND WELL BEFORE MIDNIGHT. WE/LL EXPERIENCE A
GOOD 5-8 HOURS OF RADIATIONAL COOLING NORTH AND UP TO 8-10 HOURS
SOUTH. WHILE IT WON/T BE AS COLD AS THIS MORNING...MANY SECTIONS
INLAND WILL FALL INTO THE MIDDLE 30S. THIS COMBINED WITH SMALL
DEW POINT DEPRESSIONS WILL LEAD TO AT LEAST SCATTERED FROST
ACROSS MUCH THE REGION INLAND FROM US-17. AS SUCH WE/LL MOST
LIKELY NEED TO ISSUE A FROST ADVISORY AT SOME POINT LATER TODAY.
FOR LATE TONIGHT OUR TEMPS WILL STEADY OFF OR EVEN RISE AS THE
SYNOPTIC FLOW VEERS AROUND TO THE SOUTH/SW AND WARM ADVECTION
TAKES HOLD AS A LOW LEVEL JET MOVES INTO THE AREA. CLEAR SKIES
EARLY ON WILL GIVE WAY TO SOME MID/HIGH LEVEL CLOUDS ARRIVING FROM
THE WEST/NW LATE IN ADVANCE OF THE NEXT COLD FRONT THAT WILL BE
NEARING THE APPALACHIANS BY SUNRISE.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MONDAY...A PREFRONTAL BAND OF MOISTURE...MAINLY SUPPORTED BY AN 850
MB WESTERLY JET AND ASSOCIATED CONVERGENCE/MOISTURE TRANSPORT...WILL
TRANSLATE QUICKLY TOWARD THE SOUTH/ SOUTHEAST AND THROUGH THE
FORECAST AREA. THIS FORCING SHOULD WEAKEN WITH TIME...AND THE AXIS
OF ENHANCED 850-500 MB RELATIVE HUMIDITY SHOULD BECOME LESS WELL-
DEFINED WITH TIME. GIVEN THE PERSISTENT CAP DEPICTED BY MODEL
SOUNDINGS AND THE GENERAL WEAKENING TRENDS EVIDENT IN
FORCING/ASSOCIATED MOISTURE FIELDS...CAPPED MAXIMUM POPS AT 30-40
PERCENT LATE MORNING INTO MONDAY AFTERNOON. MEANWHILE...ADJUSTED
TIMING OF TO FAVOR A FASTER TREND FAVORED BY ALL OPERATIONAL
GUIDANCE EXCEPT THE 29/00 UTC NAM. ALSO OF NOTE...A NARROW AXIS OF
SURFACE BASED INSTABILITY WILL ATTEMPT TO SPREAD EAST ESPECIALLY
MONDAY AFTERNOON...THUS A MENTION OF THUNDER REMAINS JUSTIFIED
ACROSS MAINLY SOUTHERN COUNTIES.

MONDAY AFTERNOON TEMPERATURES ARE FORECAST TO RANGE FROM THE MID 60S
FAR NORTH TO THE MID 70S FAR SOUTH. HOWEVER...IF CLOUDS/
PRECIPITATION REMAIN LESS PROMINENT THAN EXPECTED...INCREASING W/SW
WINDS COULD PUSH TEMPERATURES WELL INTO THE 70S ACROSS A WIDER SWATH
OF THE FORECAST AREA.

MONDAY NIGHT...THE PROGRESS OF THE AFOREMENTIONED/WEAKENING BAND OF
MOISTURE WILL BECOME PARALLEL TO THE UPPER FLOW AND WILL SLOW
SOUTHWARD PROGRESS...WHILE A WEAK SURFACE COLD FRONT WILL ADVANCE
INTO THE FORECAST AREA FROM THE NORTH. WHILE THE 29/00 UTC NAM IS
LIKELY OVERDONE DEPICTING A RATHER ACTIVE CONVECTIVE REGIME
ALONG/SOUTH OF I-16...A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS IS
STILL JUSTIFIED IN THIS AREA MONDAY EVENING. AFTER MIDNIGHT...POPS
ACROSS THE SOUTH TAPER TO LESS THAN 15 PERCENT WITH NO MENTION OF
PRECIPITATION. OTHERWISE...LOWS IN THE 40S/50S WILL BE COMMON
MONDAY NIGHT.

TUESDAY THROUGH WEDNESDAY...AN INITIAL COLD FRONT WILL STALL AND
DISSIPATE OVER THE REGION TUESDAY...THEN ANOTHER WEAK SURFACE COLD
FRONT WILL PUSH INTO THE AREA FROM THE NORTH WEDNESDAY. THIS SECOND
FRONT WILL ALSO STALL AND DISSIPATE OVER OR PERHAPS JUST SOUTH OF
THE REGION. MEANWHILE...A PLUME OF DEEP-LAYERED MOISTURE WILL RESIDE
JUST SOUTH AND WEST OF THE FORECAST AREA...AND THIS MOISTURE WILL
ATTEMPT TO RIDE THE WEST/NORTHWEST STEERING FLOW TOWARD THE
SOUTHEAST COAST. MODEL SOUNDINGS REMAIN SUFFICIENTLY DRY TO MAINTAIN
RAIN-FREE FORECASTS THROUGH TUESDAY NIGHT...BUT AT LEAST SLIGHT
CHANCE POPS INCLUDING A MENTION OF THUNDER ARE WARRANTED ACROSS
SOUTHERN COUNTIES WEDNESDAY. FORECAST CONFIDENCE REGARDING POPS
DURING THIS PERIOD ARE NOT HIGH...AS PRECIPITATION COULD EITHER
STREAM MORE QUICKLY INTO THE REGION LATE TUESDAY/TUESDAY NIGHT OR
COULD BE HELD MAINLY WEST OF THE REGION AS A SHORTWAVE RIDGE BUILDS
INTO THE REGION WEDNESDAY. OTHERWISE...NORMAL TO SLIGHTLY ABOVE
NORMAL HIGH TEMPERATURES IN THE 70S WILL BE COMMON BOTH DAYS...AND
NIGHTTIME LOWS MAINLY IN THE 50S CAN BE EXPECTED.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL
THEN...NORMAL TO BELOW-NORMAL TEMPERATURES SHOULD RETURN NEXT
WEEKEND.

AS AN UPPER SHORTWAVE TROUGH EJECTS EAST/NORTHEAST ACROSS THE
REGION...AT LEAST CHANCE POPS FOR SHOWERS AND THUNDERSTORMS ARE
JUSTIFIED ESPECIALLY THURSDAY. BETWEEN THE DEPARTING SHORTWAVE AND
AN APPROACHING COLD FRONT...FRIDAY COULD TURN OUT TO BE A VERY WARM
DAY WITH HIGHS IN THE 80S AND POPS BELOW 15 PERCENT WITH NO MENTION
OF PRECIPITATION. A STRONGER COLD FRONT WILL ARRIVE FRIDAY NIGHT OR
SATURDAY. TIMING REMAINS UNCERTAIN...BUT CHANCE POPS AND A MENTION
THUNDERSTORMS ARE CENTERED ON SATURDAY. DRIER AND COOLER CONDITIONS
ARE THEN EXPECTED SUNDAY.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS THIS MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...MAINLY VFR.

&&

.MARINE...
THIS MORNING...A SOLID NORTH/NE SURGE OF WINDS WILL OVERSPREAD THE
MARINE DISTRICT IN RESPONSE TO A 1030 MB HIGH BUILDING OUT OF THE
VIRGINIAS. THE ENSUING COLD ADVECTION AND ISALLOBARIC PRESSURE
RISES OF CLOSE TO 1 MB/HOUR THROUGH MID TO LATE MORNING WILL BUMP
WINDS UP TO 15 OR 20 KT EVERYWHERE. BUT THE GRADIENT WILL BE
GREATEST ON THE CHARLESTON COUNTY ATLANTIC WATERS...AND IT IS HERE
WHERE WE HAVE HOISTED A SMALL CRAFT ADVISORY THROUGH MIDDAY FOR
FREQUENT GUSTS OF 25 KT. THE OTHER WATERS WILL BE CLOSE TO
ADVISORY CONDITIONS...BUT AT PRESENT THEY LOOK TO REMAIN JUST
BELOW THE CRITERIA.

THIS AFTERNOON...RAPID IMPROVEMENT WILL OCCUR AS THE COLD
ADVECTION HALTS...PRESSURE RISES STOP AND THE CORE OF THE
CONTINENTAL HIGH SHIFTS ALMOST DIRECTLY OVERHEAD. WINDS WILL CLOCK
AROUND TO THE EAST AND DIMINISH TO 10 KT OR LESS AS SEAS ALSO FALL.

TONIGHT...WE/LL START THE NIGHT UNDERNEATH THE OFFSHORE
TRANSITIONING HIGH...RESULTING IN VERY LITTLE WIND AND LIMITED
SEAS. BUT THE HIGH DOES SLIDE SE OVERNIGHT IN ADVANCE OF THE
UPSTREAM COLD FRONT MOVING THROUGH THE OHIO/TENNESSEE VALLEYS.
THIS ALONG WITH A DECENT NOCTURNAL LOW LEVEL JET AFTER 06Z WILL
ALLOW FOR SOUTH/SW WINDS TO CLIMB AS HIGH AS 10 OR 15 KT AS SEAS
RISE MAYBE A FOOT.

MONDAY THROUGH FRIDAY...A SURGE OF SOUTHWEST WINDS IS EXPECTED AHEAD
OF AN APPROACHING COLD FRONT MONDAY. HOWEVER...GIVEN THE STABLE
MARINE ENVIRONMENT...HELD WINDS/SEAS BELOW SCA LEVELS. THE COLD
FRONT SHOULD ARRIVE FROM THE NORTH MONDAY NIGHT INTO EARLY
TUESDAY...PERHAPS ACCOMPANIED BY A MODEST SURGE OF NORTHEAST
WINDS...BUT THE PROBABILITY FOR ANY SCA CONDITIONS REMAINS VERY
LOW. THE FRONT WILL STALL AND DISSIPATE...GIVING WAY TO A WEAK
PRESSURE PATTERN TUESDAY AFTERNOON/NIGHT. ANOTHER COLD FRONT WILL
ARRIVE FROM THE NORTH WEDNESDAY...AND THIS FRONT SHOULD ALSO STALL
AND DISSIPATE OVER OR JUST SOUTH OF THE WATERS BY THURSDAY.
SOUTH/SOUTHWEST WINDS SHOULD AGAIN INCREASE AHEAD OF A STRONGER COLD
FRONT APPROACHING FROM THE NORTHWEST LATE THIS WEEK...BUT ONCE AGAIN
MARINE LAYER STABILITY COULD PREVENT SCA WINDS/SEAS.

ALSO OF NOTE...INCREASING DEWPOINTS COULD SUPPORT SOME SEA FOG OVER
NEAR SHORE WATERS ESPECIALLY THURSDAY UNTIL A COLD FROPA OCCURS
FRIDAY NIGHT OR SATURDAY. WILL CONTINUE TO ASSESS.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 290520
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
120 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT...MORE OF A DEW POINT FRONT PASSES THROUGH THE REGION
OVERNIGHT WITH COLD HIGH PRESSURE BUILDING SE FROM NORTH GEORGIA
AND THE WESTERN CAROLINAS. TEMPS WILL ACTUALLY RISE A BIT WITH THE
PASSAGE OF THIS BOUNDARY AS WINDS INCREASE...BUT DEW POINTS WILL
TANK AS THEY DROP CONSIDERABLY. AS AN EXAMPLE...KAQX BETWEEN 12
AND 1 AM WENT FROM A TEMP/DEW POINT OF 41/32 TO 45/25.

IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS
ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO 35 DURING THE
NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR THE DATE. THE
BARRIER ISLANDS WILL BE IN THE UPPER 30S WITH WARMING INFLUENCES
FROM THE ATLANTIC AND BETTER MIXING.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS SUNDAY MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290520
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
120 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT...MORE OF A DEW POINT FRONT PASSES THROUGH THE REGION
OVERNIGHT WITH COLD HIGH PRESSURE BUILDING SE FROM NORTH GEORGIA
AND THE WESTERN CAROLINAS. TEMPS WILL ACTUALLY RISE A BIT WITH THE
PASSAGE OF THIS BOUNDARY AS WINDS INCREASE...BUT DEW POINTS WILL
TANK AS THEY DROP CONSIDERABLY. AS AN EXAMPLE...KAQX BETWEEN 12
AND 1 AM WENT FROM A TEMP/DEW POINT OF 41/32 TO 45/25.

IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS
ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO 35 DURING THE
NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR THE DATE. THE
BARRIER ISLANDS WILL BE IN THE UPPER 30S WITH WARMING INFLUENCES
FROM THE ATLANTIC AND BETTER MIXING.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS SUNDAY MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 290520
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
120 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT...MORE OF A DEW POINT FRONT PASSES THROUGH THE REGION
OVERNIGHT WITH COLD HIGH PRESSURE BUILDING SE FROM NORTH GEORGIA
AND THE WESTERN CAROLINAS. TEMPS WILL ACTUALLY RISE A BIT WITH THE
PASSAGE OF THIS BOUNDARY AS WINDS INCREASE...BUT DEW POINTS WILL
TANK AS THEY DROP CONSIDERABLY. AS AN EXAMPLE...KAQX BETWEEN 12
AND 1 AM WENT FROM A TEMP/DEW POINT OF 41/32 TO 45/25.

IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS
ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO 35 DURING THE
NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR THE DATE. THE
BARRIER ISLANDS WILL BE IN THE UPPER 30S WITH WARMING INFLUENCES
FROM THE ATLANTIC AND BETTER MIXING.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS SUNDAY MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290520
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
120 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT...MORE OF A DEW POINT FRONT PASSES THROUGH THE REGION
OVERNIGHT WITH COLD HIGH PRESSURE BUILDING SE FROM NORTH GEORGIA
AND THE WESTERN CAROLINAS. TEMPS WILL ACTUALLY RISE A BIT WITH THE
PASSAGE OF THIS BOUNDARY AS WINDS INCREASE...BUT DEW POINTS WILL
TANK AS THEY DROP CONSIDERABLY. AS AN EXAMPLE...KAQX BETWEEN 12
AND 1 AM WENT FROM A TEMP/DEW POINT OF 41/32 TO 45/25.

IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS
ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO 35 DURING THE
NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR THE DATE. THE
BARRIER ISLANDS WILL BE IN THE UPPER 30S WITH WARMING INFLUENCES
FROM THE ATLANTIC AND BETTER MIXING.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS SUNDAY MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 290516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
116 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT...MORE OF A DEW POINT FRONT PASSES THROUGH THE REGION
OVERNIGHT WITH COLD HIGH PRESSURE BUILDING SE FROM NORTH GEORGIA
AND THE WESTERN CAROLINAS. TEMPS WILL ACTUALLY RISE A BIT WITH THE
PASSAGE OF THIS BOUNDARY AS WINDS INCREASE...BUT DEW POINTS WILL
TANK AS THEY DROP CONSIDERABLY. AS AN EXAMPLE...KAQX BETWEEN 12
AND 1 AM WENT FROM A TEMP/DEW POINT OF 41/32 TO 45/25.

IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS
ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO 35 DURING THE
NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR THE DATE.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS SUNDAY MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
116 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT...MORE OF A DEW POINT FRONT PASSES THROUGH THE REGION
OVERNIGHT WITH COLD HIGH PRESSURE BUILDING SE FROM NORTH GEORGIA
AND THE WESTERN CAROLINAS. TEMPS WILL ACTUALLY RISE A BIT WITH THE
PASSAGE OF THIS BOUNDARY AS WINDS INCREASE...BUT DEW POINTS WILL
TANK AS THEY DROP CONSIDERABLY. AS AN EXAMPLE...KAQX BETWEEN 12
AND 1 AM WENT FROM A TEMP/DEW POINT OF 41/32 TO 45/25.

IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS
ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO 35 DURING THE
NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR THE DATE.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS SUNDAY MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 290516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
116 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT...MORE OF A DEW POINT FRONT PASSES THROUGH THE REGION
OVERNIGHT WITH COLD HIGH PRESSURE BUILDING SE FROM NORTH GEORGIA
AND THE WESTERN CAROLINAS. TEMPS WILL ACTUALLY RISE A BIT WITH THE
PASSAGE OF THIS BOUNDARY AS WINDS INCREASE...BUT DEW POINTS WILL
TANK AS THEY DROP CONSIDERABLY. AS AN EXAMPLE...KAQX BETWEEN 12
AND 1 AM WENT FROM A TEMP/DEW POINT OF 41/32 TO 45/25.

IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS
ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO 35 DURING THE
NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR THE DATE.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS SUNDAY MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
116 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT...MORE OF A DEW POINT FRONT PASSES THROUGH THE REGION
OVERNIGHT WITH COLD HIGH PRESSURE BUILDING SE FROM NORTH GEORGIA
AND THE WESTERN CAROLINAS. TEMPS WILL ACTUALLY RISE A BIT WITH THE
PASSAGE OF THIS BOUNDARY AS WINDS INCREASE...BUT DEW POINTS WILL
TANK AS THEY DROP CONSIDERABLY. AS AN EXAMPLE...KAQX BETWEEN 12
AND 1 AM WENT FROM A TEMP/DEW POINT OF 41/32 TO 45/25.

IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS
ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO 35 DURING THE
NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR THE DATE.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 06Z MONDAY. FOR THE SAKE OF
SIMPLICITY WE HAVE SHOWN MORE OF AVERAGE WINDS IN THE 06Z
TAFS...BUT THERE WILL BE SOME GUSTS SUNDAY MORNING AND WINDS
TONIGHT WILL ACTUALLY GO LIGHT/VARIABLE OR EVEN CALM.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088.
SC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 290456
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1256 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT PASSES THROUGH THE REGION OVERNIGHT WITH COLD HIGH
PRESSURE BUILDING SE FROM NORTH GEORGIA AND THE WESTERN
CAROLINAS. IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD
ADVECTION IS ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO
35 DURING THE NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR
THE DATE.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT THIS MORNING FOR GAZ087-
     088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT THIS MORNING FOR SCZ040-
     042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 290456
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1256 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT PASSES THROUGH THE REGION OVERNIGHT WITH COLD HIGH
PRESSURE BUILDING SE FROM NORTH GEORGIA AND THE WESTERN
CAROLINAS. IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD
ADVECTION IS ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO
35 DURING THE NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR
THE DATE.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT THIS MORNING FOR GAZ087-
     088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT THIS MORNING FOR SCZ040-
     042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290456
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1256 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT PASSES THROUGH THE REGION OVERNIGHT WITH COLD HIGH
PRESSURE BUILDING SE FROM NORTH GEORGIA AND THE WESTERN
CAROLINAS. IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD
ADVECTION IS ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO
35 DURING THE NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR
THE DATE.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT THIS MORNING FOR GAZ087-
     088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT THIS MORNING FOR SCZ040-
     042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 290456
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1256 AM EDT SUN MAR 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ASIDE OF SOME MID LEVEL CLOUDS SKIRTING THE ALTAMAHA RIVER SKIES
WILL BE CLEAR OVERNIGHT.

NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT PASSES THROUGH THE REGION OVERNIGHT WITH COLD HIGH
PRESSURE BUILDING SE FROM NORTH GEORGIA AND THE WESTERN
CAROLINAS. IN THE WAKE OF THE FRONT A REINFORCING ROUND OF COLD
ADVECTION IS ON TAP OVERNIGHT. TEMPERATURES WILL REACH THE 30 TO
35 DURING THE NEAR-DAWN HOURS. THIS IS CLOSE TO RECORD LOWS FOR
THE DATE.

THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER OF COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN WITH THIS PACKAGE.
MODELS CONTINUE TO INDICATE FALLING SURFACE DEW POINTS AND
INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS CONCERNS FOR
WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING THE FREEZE
WARNINGS IN PLACE. BUT PATCHY FROST WILL STILL BE EVIDENT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING. WE WILL KEEP A SHARP EYE ON A POTENTIAL SMALL CRAFT
ADVISORY.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT THIS MORNING FOR GAZ087-
     088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT THIS MORNING FOR SCZ040-
     042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290155
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
955 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SKIES WERE CLEAR THIS EVENING ACROSS THE FORECAST AREA AS THE
LAST FEW POCKETS OF FAIR WEATHER CLOUDS DISSIPATED AFTER SUNSET.
NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT PASSES THROUGH THE REGION OVERNIGHT WITH COLD HIGH PRES
BUILDING SE FROM NORTH GEORGIA AND THE WESTERN CAROLINAS. IN THE
WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS ON TAP
OVERNIGHT. TEMPERATURES SHOULD REACH THE LOW TO MID 30S DURING THE
NEAR-DAWN HOURS. THE ONGOING FREEZE WARNING FOR THE NORTHWEST
TIER OF COUNTIES LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN
WITH THIS PACKAGE. MODELS CONTINUE TO INDICATE FALLING SURFACE DEW
POINTS AND INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS
CONCERNS FOR WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING
THE FREEZE WARNINGS IN PLACE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 290155
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
955 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SKIES WERE CLEAR THIS EVENING ACROSS THE FORECAST AREA AS THE
LAST FEW POCKETS OF FAIR WEATHER CLOUDS DISSIPATED AFTER SUNSET.
NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT PASSES THROUGH THE REGION OVERNIGHT WITH COLD HIGH PRES
BUILDING SE FROM NORTH GEORGIA AND THE WESTERN CAROLINAS. IN THE
WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS ON TAP
OVERNIGHT. TEMPERATURES SHOULD REACH THE LOW TO MID 30S DURING THE
NEAR-DAWN HOURS. THE ONGOING FREEZE WARNING FOR THE NORTHWEST
TIER OF COUNTIES LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN
WITH THIS PACKAGE. MODELS CONTINUE TO INDICATE FALLING SURFACE DEW
POINTS AND INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS
CONCERNS FOR WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING
THE FREEZE WARNINGS IN PLACE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 290155
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
955 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SKIES WERE CLEAR THIS EVENING ACROSS THE FORECAST AREA AS THE
LAST FEW POCKETS OF FAIR WEATHER CLOUDS DISSIPATED AFTER SUNSET.
NO SIGNIFICANT CHANGES ON THE EVENING FORECAST AS A SECONDARY DRY
COLD FRONT PASSES THROUGH THE REGION OVERNIGHT WITH COLD HIGH PRES
BUILDING SE FROM NORTH GEORGIA AND THE WESTERN CAROLINAS. IN THE
WAKE OF THE FRONT A REINFORCING ROUND OF COLD ADVECTION IS ON TAP
OVERNIGHT. TEMPERATURES SHOULD REACH THE LOW TO MID 30S DURING THE
NEAR-DAWN HOURS. THE ONGOING FREEZE WARNING FOR THE NORTHWEST
TIER OF COUNTIES LOOKS ON TRACK AND HAS NEEDED NO CHANGE AGAIN
WITH THIS PACKAGE. MODELS CONTINUE TO INDICATE FALLING SURFACE DEW
POINTS AND INCREASING TEMP/DEW POINT SPREADS OVERNIGHT...THUS
CONCERNS FOR WIDESPREAD FROST APPEARS LOW IN LOCATIONS BORDERING
THE FREEZE WARNINGS IN PLACE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...COLD HIGH PRESSURE WILL STEADILY BUILD FROM THE OHIO
VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE ACCOMPANYING
COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL ALLOW NW WINDS
TO VEER NORTH AND SURGE AFTER MIDNIGHT NORTHERN WATERS AND CLOSER
TO DAYBREAK GEORGIA LEGS. NORTH WINDS COULD NEAR 20 KT WITH HIGHER
GUSTS LATE ACROSS THE CHARLESTON COUNTY WATERS AND OFFSHORE
GEORGIA ZONES FOR A SHORT WINDOW LATER TONIGHT AND EARLY SUNDAY
MORNING.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 282330
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
730 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
QUIET AND COLD CONDITIONS WILL CONTINUE TONIGHT. THE AXIS OF AN
EXPANSIVE UPPER TROUGH WILL LINGER ALONG THE EAST COAST...WHILE
THE CENTER OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY SLIPS
SOUTHEAST. THE LEADING EDGE OF THE SURFACE HIGH WILL ACT AS A
SECONDARY DRY COLD FRONT...INTRODUCING A REINFORCING ROUND OF COLD
ADVECTION OVERNIGHT. AS A RESULT...EXPECT TEMPERATURES TO RAPIDLY
FALL AFTER SUNSET AND REACH THE LOW TO MID 30S DURING THE PRE DAWN
HOURS. THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE WITH THIS FORECAST
PACKAGE. WILL THEREFORE CONTINUE TO ADVERTISE ABOUT 3 TO 5 HOURS
OF MINIMUM TEMPERATURES AT 30 TO 32 DEGREES FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS COUNTIES.
THE TOOLS UTILIZED TO DETERMINE FROST POTENTIAL HAVE CONSISTENTLY
RETURNED LOW CONFIDENCE IN ANYTHING MORE THAN PATCHY
FROST...LIKELY DUE TO THE COMBINED EFFECTS OF LARGER DEWPOINT
DEPRESSIONS AND SOMEWHAT ELEVATED NOCTURNAL WIND SPEEDS WITHIN A
TIGHTENED PRESSURE GRADIENT. THEREFORE PREFER NOT TO ISSUE FROST
ADVISORIES FOR THE AREAS OUTSIDE OF THE FREEZE WARNING AT THIS
TIME. IT SHOULD ALSO BE NOTED THAT LOW TEMPERATURES WILL APPROACH
RECORDS FOR MARCH 29...SEE CLIMATE SECTION BELOW FOR MORE
INFORMATION.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...STRONG SURFACE HIGH PRESSURE WILL STEADILY BUILD FROM
THE OHIO VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE
ACCOMPANYING COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL
ALLOW NW WINDS TO VEER NORTH AND INCREASE. NORTH WINDS COULD
SURGE TO 20 KT LATE ACROSS THE CHARLESTON COUNTY WATERS AND
OFFSHORE GEORGIA ZONES...HOWEVER LATEST THINKING IS THAT
CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY CONDITIONS.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 282330
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
730 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
QUIET AND COLD CONDITIONS WILL CONTINUE TONIGHT. THE AXIS OF AN
EXPANSIVE UPPER TROUGH WILL LINGER ALONG THE EAST COAST...WHILE
THE CENTER OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY SLIPS
SOUTHEAST. THE LEADING EDGE OF THE SURFACE HIGH WILL ACT AS A
SECONDARY DRY COLD FRONT...INTRODUCING A REINFORCING ROUND OF COLD
ADVECTION OVERNIGHT. AS A RESULT...EXPECT TEMPERATURES TO RAPIDLY
FALL AFTER SUNSET AND REACH THE LOW TO MID 30S DURING THE PRE DAWN
HOURS. THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE WITH THIS FORECAST
PACKAGE. WILL THEREFORE CONTINUE TO ADVERTISE ABOUT 3 TO 5 HOURS
OF MINIMUM TEMPERATURES AT 30 TO 32 DEGREES FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS COUNTIES.
THE TOOLS UTILIZED TO DETERMINE FROST POTENTIAL HAVE CONSISTENTLY
RETURNED LOW CONFIDENCE IN ANYTHING MORE THAN PATCHY
FROST...LIKELY DUE TO THE COMBINED EFFECTS OF LARGER DEWPOINT
DEPRESSIONS AND SOMEWHAT ELEVATED NOCTURNAL WIND SPEEDS WITHIN A
TIGHTENED PRESSURE GRADIENT. THEREFORE PREFER NOT TO ISSUE FROST
ADVISORIES FOR THE AREAS OUTSIDE OF THE FREEZE WARNING AT THIS
TIME. IT SHOULD ALSO BE NOTED THAT LOW TEMPERATURES WILL APPROACH
RECORDS FOR MARCH 29...SEE CLIMATE SECTION BELOW FOR MORE
INFORMATION.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...STRONG SURFACE HIGH PRESSURE WILL STEADILY BUILD FROM
THE OHIO VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE
ACCOMPANYING COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL
ALLOW NW WINDS TO VEER NORTH AND INCREASE. NORTH WINDS COULD
SURGE TO 20 KT LATE ACROSS THE CHARLESTON COUNTY WATERS AND
OFFSHORE GEORGIA ZONES...HOWEVER LATEST THINKING IS THAT
CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY CONDITIONS.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 282330
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
730 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
QUIET AND COLD CONDITIONS WILL CONTINUE TONIGHT. THE AXIS OF AN
EXPANSIVE UPPER TROUGH WILL LINGER ALONG THE EAST COAST...WHILE
THE CENTER OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY SLIPS
SOUTHEAST. THE LEADING EDGE OF THE SURFACE HIGH WILL ACT AS A
SECONDARY DRY COLD FRONT...INTRODUCING A REINFORCING ROUND OF COLD
ADVECTION OVERNIGHT. AS A RESULT...EXPECT TEMPERATURES TO RAPIDLY
FALL AFTER SUNSET AND REACH THE LOW TO MID 30S DURING THE PRE DAWN
HOURS. THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE WITH THIS FORECAST
PACKAGE. WILL THEREFORE CONTINUE TO ADVERTISE ABOUT 3 TO 5 HOURS
OF MINIMUM TEMPERATURES AT 30 TO 32 DEGREES FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS COUNTIES.
THE TOOLS UTILIZED TO DETERMINE FROST POTENTIAL HAVE CONSISTENTLY
RETURNED LOW CONFIDENCE IN ANYTHING MORE THAN PATCHY
FROST...LIKELY DUE TO THE COMBINED EFFECTS OF LARGER DEWPOINT
DEPRESSIONS AND SOMEWHAT ELEVATED NOCTURNAL WIND SPEEDS WITHIN A
TIGHTENED PRESSURE GRADIENT. THEREFORE PREFER NOT TO ISSUE FROST
ADVISORIES FOR THE AREAS OUTSIDE OF THE FREEZE WARNING AT THIS
TIME. IT SHOULD ALSO BE NOTED THAT LOW TEMPERATURES WILL APPROACH
RECORDS FOR MARCH 29...SEE CLIMATE SECTION BELOW FOR MORE
INFORMATION.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...STRONG SURFACE HIGH PRESSURE WILL STEADILY BUILD FROM
THE OHIO VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE
ACCOMPANYING COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL
ALLOW NW WINDS TO VEER NORTH AND INCREASE. NORTH WINDS COULD
SURGE TO 20 KT LATE ACROSS THE CHARLESTON COUNTY WATERS AND
OFFSHORE GEORGIA ZONES...HOWEVER LATEST THINKING IS THAT
CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY CONDITIONS.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 282330
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
730 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
QUIET AND COLD CONDITIONS WILL CONTINUE TONIGHT. THE AXIS OF AN
EXPANSIVE UPPER TROUGH WILL LINGER ALONG THE EAST COAST...WHILE
THE CENTER OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY SLIPS
SOUTHEAST. THE LEADING EDGE OF THE SURFACE HIGH WILL ACT AS A
SECONDARY DRY COLD FRONT...INTRODUCING A REINFORCING ROUND OF COLD
ADVECTION OVERNIGHT. AS A RESULT...EXPECT TEMPERATURES TO RAPIDLY
FALL AFTER SUNSET AND REACH THE LOW TO MID 30S DURING THE PRE DAWN
HOURS. THE ONGOING FREEZE WARNING FOR THE NORTHWEST TIER COUNTIES
LOOKS ON TRACK AND HAS NEEDED NO CHANGE WITH THIS FORECAST
PACKAGE. WILL THEREFORE CONTINUE TO ADVERTISE ABOUT 3 TO 5 HOURS
OF MINIMUM TEMPERATURES AT 30 TO 32 DEGREES FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS COUNTIES.
THE TOOLS UTILIZED TO DETERMINE FROST POTENTIAL HAVE CONSISTENTLY
RETURNED LOW CONFIDENCE IN ANYTHING MORE THAN PATCHY
FROST...LIKELY DUE TO THE COMBINED EFFECTS OF LARGER DEWPOINT
DEPRESSIONS AND SOMEWHAT ELEVATED NOCTURNAL WIND SPEEDS WITHIN A
TIGHTENED PRESSURE GRADIENT. THEREFORE PREFER NOT TO ISSUE FROST
ADVISORIES FOR THE AREAS OUTSIDE OF THE FREEZE WARNING AT THIS
TIME. IT SHOULD ALSO BE NOTED THAT LOW TEMPERATURES WILL APPROACH
RECORDS FOR MARCH 29...SEE CLIMATE SECTION BELOW FOR MORE
INFORMATION.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR AT KCHS AND KSAV THROUGH 00Z MONDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
ON MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...STRONG SURFACE HIGH PRESSURE WILL STEADILY BUILD FROM
THE OHIO VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE
ACCOMPANYING COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL
ALLOW NW WINDS TO VEER NORTH AND INCREASE. NORTH WINDS COULD
SURGE TO 20 KT LATE ACROSS THE CHARLESTON COUNTY WATERS AND
OFFSHORE GEORGIA ZONES...HOWEVER LATEST THINKING IS THAT
CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY CONDITIONS.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 282005
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
405 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
QUIET AND COLD CONDITIONS WILL CONTINUE THROUGH TONIGHT. THE AXIS
OF AN EXPANSIVE UPPER TROUGH WILL LINGER ALONG THE EAST
COAST...WHILE THE CENTER OF SURFACE HIGH PRESSURE OVER THE OHIO
VALLEY SLIPS SOUTHEAST. THE LEADING EDGE OF THE SURFACE HIGH WILL
ACT AS A SECONDARY DRY COLD FRONT...INTRODUCING A REINFORCING
ROUND OF COLD ADVECTION OVERNIGHT. AS A RESULT...EXPECT
TEMPERATURES TO RAPIDLY FALL AFTER SUNSET AND REACH THE LOW TO
MID 30S DURING THE PRE DAWN HOURS. THE ONGOING FREEZE WARNING FOR
THE NORTHWEST TIER COUNTIES LOOKS ON TRACK AND HAS NEEDED NO
CHANGE WITH THIS FORECAST PACKAGE. WILL THEREFORE CONTINUE TO
ADVERTISE ABOUT 3 TO 5 HOURS OF MINIMUM TEMPERATURES AT 30 TO 32
DEGREES FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS COUNTIES. THE TOOLS UTILIZED TO
DETERMINE FROST POTENTIAL HAVE CONSISTENTLY RETURNED LOW
CONFIDENCE IN ANYTHING MORE THAN PATCHY FROST...LIKELY DUE TO THE
COMBINED EFFECTS OF LARGER DEWPOINT DEPRESSIONS AND SOMEWHAT
ELEVATED NOCTURNAL WIND SPEEDS WITHIN A TIGHTENED PRESSURE
GRADIENT. THEREFORE PREFER NOT TO ISSUE FROST ADVISORIES FOR THE
AREAS OUTSIDE OF THE FREEZE WARNING AT THIS TIME. IT SHOULD ALSO
BE NOTED THAT LOW TEMPERATURES WILL APPROACH RECORDS FOR MARCH
29...SEE CLIMATE SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 18Z SUNDAY. BREEZY
WEST/NORTHWEST WINDS THIS AFTERNOON WILL DIMINISH BY THE
EVENING...EVENTUALLY BECOMING NORTH BEHIND A DRY COLD FRONT AFTER
MIDNIGHT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...STRONG SURFACE HIGH PRESSURE WILL STEADILY BUILD FROM
THE OHIO VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE
ACCOMPANYING COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL
ALLOW WEST WINDS TO VEER NORTH AND INCREASE. NORTH/NORTHWEST WINDS
COULD SURGE TO 15 TO 20 KT LATE ACROSS THE CHARLESTON COUNTY
WATERS AND OFFSHORE GEORGIA ZONES...HOWEVER LATEST THINKING IS
THAT CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY CONDITIONS.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...WMS
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...WMS/FWA
MARINE...WMS/FWA/SPR
CLIMATE...




000
FXUS62 KCHS 282005
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
405 PM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL THROUGH SUNDAY. WEAK COLD FRONTS WILL
PUSH INTO THE REGION MONDAY AND AGAIN WEDNESDAY...AND BOTH FRONTS
SHOULD DISSIPATE OVER OR CLOSE TO THE AREA. WARMER ATLANTIC HIGH
PRESSURE WILL THEN BUILD OVER THE REGION THROUGH LATE WEEK. A
STRONGER COLD FRONT WILL ARRIVE NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
QUIET AND COLD CONDITIONS WILL CONTINUE THROUGH TONIGHT. THE AXIS
OF AN EXPANSIVE UPPER TROUGH WILL LINGER ALONG THE EAST
COAST...WHILE THE CENTER OF SURFACE HIGH PRESSURE OVER THE OHIO
VALLEY SLIPS SOUTHEAST. THE LEADING EDGE OF THE SURFACE HIGH WILL
ACT AS A SECONDARY DRY COLD FRONT...INTRODUCING A REINFORCING
ROUND OF COLD ADVECTION OVERNIGHT. AS A RESULT...EXPECT
TEMPERATURES TO RAPIDLY FALL AFTER SUNSET AND REACH THE LOW TO
MID 30S DURING THE PRE DAWN HOURS. THE ONGOING FREEZE WARNING FOR
THE NORTHWEST TIER COUNTIES LOOKS ON TRACK AND HAS NEEDED NO
CHANGE WITH THIS FORECAST PACKAGE. WILL THEREFORE CONTINUE TO
ADVERTISE ABOUT 3 TO 5 HOURS OF MINIMUM TEMPERATURES AT 30 TO 32
DEGREES FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS COUNTIES. THE TOOLS UTILIZED TO
DETERMINE FROST POTENTIAL HAVE CONSISTENTLY RETURNED LOW
CONFIDENCE IN ANYTHING MORE THAN PATCHY FROST...LIKELY DUE TO THE
COMBINED EFFECTS OF LARGER DEWPOINT DEPRESSIONS AND SOMEWHAT
ELEVATED NOCTURNAL WIND SPEEDS WITHIN A TIGHTENED PRESSURE
GRADIENT. THEREFORE PREFER NOT TO ISSUE FROST ADVISORIES FOR THE
AREAS OUTSIDE OF THE FREEZE WARNING AT THIS TIME. IT SHOULD ALSO
BE NOTED THAT LOW TEMPERATURES WILL APPROACH RECORDS FOR MARCH
29...SEE CLIMATE SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...AFTER A COLD START...TEMPERATURES WILL WARM UP UNDER
PLENTIFUL SUNSHINE TO THE UPPER 50S NORTH TO LOWER 60S SOUTH BY LATE
AFTERNOON AS POLAR HIGH PRESSURE SETTLES OVER THE AREA. THOSE TEMPS
ARE 10 DEGREES OR MORE BELOW AVERAGE. RELATIVE HUMIDITIES WILL BE
UNSEASONABLY LOW AS WELL WITH VALUES INTO THE TEENS AWAY FROM THE
COAST BY AFTERNOON. FORTUNATELY...WINDS WILL BE LIGHT...SO FIRE
WEATHER CONCERNS WILL NOT BE LARGE.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS. I AM
CONCERNED THAT WE COULD GET CLOSE TO FREEZING NEAR THE SANTEE RIVER
DURING THE LATE EVENING HOURS IN THE USUAL COLD SPOTS AROUND THE
FRANCIS MARION. FOR NOW...I DID NOT DROP THE TEMPS BELOW 34...BUT
THIS WILL NEED TO BE WATCHED. FROST WOULD ALSO BE POSSIBLE IN THOSE
AREAS. LATER AT NIGHT...AS THE GRADIENT TIGHTENS BETWEEN HIGH
PRESSURE SHIFTING SOUTH OF THE REGION AND A COLD FRONT APPROACHING
FROM THE NORTHWEST...AND AS CLOUDS BEGIN TO INCREASE...OVERNIGHT
TEMPERATURES WILL BEGIN TO SLOWLY RISE. THUS...HOURLY TEMPERATURES
INDICATE LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...FOLLOWED BY
SLIGHTLY HIGHER TEMPS AROUND DAYBREAK MONDAY.

MONDAY...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY FROM
NORTHWEST TO SOUTHEAST. MODELS ARE A LITTLE MORE AGGRESSIVE IN THE
CHANCES OF RAIN WITH THE FRONT...SO I HAVE INCREASED POPS AND CLOUD
COVER JUST A TOUCH. AREAS THAT HAVE TEMPS REACH 70 OR ABOVE MAY GET
ENOUGH SURFACE INSTABILITY TO GENERATE SOME ISOLATED
THUNDERSTORMS...SO I DID ADD A SLIGHT CHANCE OF THUNDER DURING THE
AFTERNOON HOURS...AS WELL AS THE EARLY EVENING PRIOR TO SUNSET OVER
THE SOUTH.

MONDAY NIGHT...THE COLD FRONT WILL WEAKEN AND PUSH SOUTHEAST OF THE
AREA...ENDING THE THREAT FOR RAIN MOST PLACES. WITH THE FRONT
SLOWING DOWN CONSIDERABLY...I CANT RULE OUT A LINGERING SHOWER IN
THE SOUTHERN AREAS...SO A SLIGHT CHANCE OF POPS REMAINS SOUTH OF
ROUGHLY INTERSTATE 16. IF ANY SHOWERS DO OCCUR...AMOUNTS WILL BE
GENERALLY LIGHT. TEMPS WILL BE DOWN TO THE 40S TO NEAR 50 BY MORNING
AS WEAK PRESSURE BRIEFLY VISITS THE AREA.

TUESDAY...HIGH PRESSURE WILL WORK ITS WAY INTO THE ATLANTIC DURING
THE DAY TUESDAY...ALLOWING FOR A MILDER SOUTHWESTERLY WIND TO
DEVELOP. TEMPERATURES SHOULD GET TO 70 OR ABOVE DURING THE
AFTERNOON...ALTHOUGH PROBABLY 10 DEGREES COOLER DURING THE AFTERNOON
ALONG THE COAST AS THE WINDS BACK TO SOUTHERLY IN SC AND SOUTH
SOUTHEASTERLY IN GEORGIA. MOISTURE WILL ALSO BE INCREASING...SO I
HAVE MAINTAINED THE LOW END POPS FOR SOUTH IF INTERSTATE 16 THAT I
INHERITED FROM THE PREVIOUS FORECAST...BUT THAT IS PROBABLY A
TOUCH AGGRESSIVE...AND CERTAINLY IT DOES NOT LOOK ANYTHING LIKE A
WASHOUT OF A DAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 18Z SUNDAY. BREEZY
WEST/NORTHWEST WINDS THIS AFTERNOON WILL DIMINISH BY THE
EVENING...EVENTUALLY BECOMING NORTH BEHIND A DRY COLD FRONT AFTER
MIDNIGHT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...STRONG SURFACE HIGH PRESSURE WILL STEADILY BUILD FROM
THE OHIO VALLEY AND EXPAND ACROSS THE LOCAL WATERS OVERNIGHT. THE
ACCOMPANYING COLD ADVECTION AND TIGHTENED PRESSURE GRADIENT WILL
ALLOW WEST WINDS TO VEER NORTH AND INCREASE. NORTH/NORTHWEST WINDS
COULD SURGE TO 15 TO 20 KT LATE ACROSS THE CHARLESTON COUNTY
WATERS AND OFFSHORE GEORGIA ZONES...HOWEVER LATEST THINKING IS
THAT CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY CONDITIONS.

SUNDAY THROUGH THURSDAY...WINDS WILL BE QUITE CHANGEABLE DURING
THE SUNDAY THROUGH THURSDAY TIME FRAME...BUT EXCEPT FOR POSSIBLY A
PERIOD MONDAY AFTERNOON AHEAD OF A FRONT...HEADLINES SEEM
UNLIKELY.

HIGH PRESSURE ON SUNDAY WILL SETTLE RIGHT OVER THE COASTAL
WATERS...LEADING TO A WEAKENING IN THE WINDS...WHICH SHOULD
EVENTUALLY VEER TO AN ONSHORE DIRECTION DURING THE AFTERNOON. WINDS
WILL TURN SOUTHERLY...THEN SOUTHWESTERLY SUNDAY NIGHT AHEAD OF A
COLD FRONT...INCREASING IN SPEED MONDAY. THERE IS A CHANCE WE WILL
NEED SMALL CRAFT ADVISORIES MONDAY AFTERNOON IN THE CHARLESTON
COUNTY WATERS...ALONG WITH THE OUTER GEORGIA WATERS...BUT FOR NOW I
HAVE KEPT THE SUSTAINED WINDS JUST BELOW HEADLINE CRITERIA AT 20
KNOTS OR SO. WINDS WILL VEER TO THE NORTHWEST AND COME BACK DOWN IN
SPEED MONDAY NIGHT BEHIND THE FRONT...AND TUESDAY THE WINDS SLACKEN
AS THE NEXT AREA OF WEAK HIGH PRESSURE SETTLES OVER THE WATERS.
ANOTHER FRONT IS EXPECTED TO PASS THROUGH WEDNESDAY...WITH WINDS
TURNING NORTHEASTERLY BEHIND THE FRONT WEDNESDAY NIGHT...VEERING
AROUND TO SOUTHEASTERLY BY THURSDAY AFTERNOON. SPEEDS WILL BE
GENERALLY 15 KNOTS OR LESS DURING THE MIDDLE OF THE WEEK.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...WMS
SHORT TERM...FWA
LONG TERM...SPR
AVIATION...WMS/FWA
MARINE...WMS/FWA/SPR
CLIMATE...





000
FXUS62 KCHS 281745
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
145 PM EDT SAT MAR 28 2015

.SYNOPSIS...
COLD CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...AN EXPANSIVE UPPER LEVEL TROUGH WILL REMAIN ANCHORED OVER
THE EASTERN UNITED STATES...WHILE STRONG HIGH PRESSURE CONTINUES
TO BUILD TOWARD THE EAST COAST. THIS PATTERN WILL SUPPORT RATHER
QUIET YET COLD CONDITIONS ACROSS THE FORECAST AREA TODAY.
SCATTERED MID LEVEL CLOUDS HAVE DEVELOPED ACROSS PORTIONS OF THE
FORECAST AREA BY EARLY AFTERNOON...HOWEVER EXPECT SKY COVER TO
REMAIN PARTLY CLOUDY OR LESS. HIGH TEMPERATURES WILL BE THE
COMBINED RESULT OF GRADUALLY WEAKENING COLD ADVECTION AND LOWER
HEIGHTS ALOFT...AS WELL AS THE WARMING EFFECTS OF A DOWNSLOPE FLOW
COMPONENT WITHIN WEST/NORTHWEST WINDS AND DECENT INSOLATION.
THUS...TEMPERATURES WILL PEAK ONLY IN THE UPPER 50S NORTH TO THE
LOW 60S SOUTH...10 TO 15 DEGREES BELOW SEASONAL NORMALS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF
THE LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT...WILL PUSH THROUGH THE REGION OVERNIGHT. THIS ALLOWS THE
UPSTREAM AND COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM
THE NORTHWEST WITH STEADILY RISING PRESSURES. IT ALSO ARRIVES
WITH ANOTHER INFLUX OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR
FREEZING TEMPS TO PENETRATE INTO AT LEAST THE NORTHWEST TIER.
AFTER COORDINATION WITH NEIGHBORING OFFICES...HAVE UPGRADED THE
EARLIER FREEZE WATCH TO A FREEZE WARNING FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS. THIS IS DUE
TO MIN TEMPS OF 30-32F FOR 3-5 HOURS LATE TONIGHT AND EARLY
SUNDAY...ALONG WITH PATCHY FROST. ALTHOUGH A HARD FREEZE IS NOT
EXPECTED...THESE CONDITIONS ARE SUFFICIENT TO CAUSE DAMAGE TO
SENSITIVE VEGETATION AND UNPROTECTED PLANTS.

CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. HOWEVER THERE ARE TWO
FACTORS GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD
BE THAT THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10
DEGREES. SECOND...THERE WILL BE TOO MUCH MIXING IN SOME OF THESE
AREAS DUE TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP
NEAR 10 OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS
MIGHT WANT TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE
30S. IT IS ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE
TO PENETRATE A BIT FURTHER SOUTHEAST...A FEW PARTS OF THIS
CORRIDOR OF COUNTIES COULD ALSO REQUIRE A FREEZE WARNING. THE
ONLY PLACES THAT SHOULD ESCAPE ANY FROST AND/OR FREEZE WILL BE THE
COASTAL SOUTHEAST GEORGIA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT TWO DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 18Z SUNDAY. BREEZY
WEST/NORTHWEST WINDS THIS AFTERNOON WILL DIMINISH BY THE
EVENING...EVENTUALLY BECOMING NORTH BEHIND A DRY COLD FRONT AFTER
MIDNIGHT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...WANING COLD ADVECTION AND A SLIGHT WEAKENING OF THE
PRESSURE GRADIENT HAS ALLOWED CONDITIONS TO IMPROVE OVER THE
WATERS. SMALL CRAFT ADVISORIES ARE NO LONGER IN EFFECT.

TONIGHT...THE IMPROVEMENT IN CONDITIONS WILL BE SHORT-LIVED AS A
STRENGTHENING CONTINENTAL HIGH BUILDS FROM THE OHIO VALLEY AND
EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE EVENING AND
OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER ROUND OF COLD
ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NORTHEAST SURGE
WILL OCCUR LATE. CONDITIONS COULD ACTUALLY APPROACH SMALL CRAFT
ADVISORY CRITERIA ON THE CHARLESTON COUNTY ATLANTIC WATERS AS
SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...WMS/
CLIMATE...




000
FXUS62 KCHS 281745
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
145 PM EDT SAT MAR 28 2015

.SYNOPSIS...
COLD CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...AN EXPANSIVE UPPER LEVEL TROUGH WILL REMAIN ANCHORED OVER
THE EASTERN UNITED STATES...WHILE STRONG HIGH PRESSURE CONTINUES
TO BUILD TOWARD THE EAST COAST. THIS PATTERN WILL SUPPORT RATHER
QUIET YET COLD CONDITIONS ACROSS THE FORECAST AREA TODAY.
SCATTERED MID LEVEL CLOUDS HAVE DEVELOPED ACROSS PORTIONS OF THE
FORECAST AREA BY EARLY AFTERNOON...HOWEVER EXPECT SKY COVER TO
REMAIN PARTLY CLOUDY OR LESS. HIGH TEMPERATURES WILL BE THE
COMBINED RESULT OF GRADUALLY WEAKENING COLD ADVECTION AND LOWER
HEIGHTS ALOFT...AS WELL AS THE WARMING EFFECTS OF A DOWNSLOPE FLOW
COMPONENT WITHIN WEST/NORTHWEST WINDS AND DECENT INSOLATION.
THUS...TEMPERATURES WILL PEAK ONLY IN THE UPPER 50S NORTH TO THE
LOW 60S SOUTH...10 TO 15 DEGREES BELOW SEASONAL NORMALS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF
THE LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT...WILL PUSH THROUGH THE REGION OVERNIGHT. THIS ALLOWS THE
UPSTREAM AND COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM
THE NORTHWEST WITH STEADILY RISING PRESSURES. IT ALSO ARRIVES
WITH ANOTHER INFLUX OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR
FREEZING TEMPS TO PENETRATE INTO AT LEAST THE NORTHWEST TIER.
AFTER COORDINATION WITH NEIGHBORING OFFICES...HAVE UPGRADED THE
EARLIER FREEZE WATCH TO A FREEZE WARNING FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS. THIS IS DUE
TO MIN TEMPS OF 30-32F FOR 3-5 HOURS LATE TONIGHT AND EARLY
SUNDAY...ALONG WITH PATCHY FROST. ALTHOUGH A HARD FREEZE IS NOT
EXPECTED...THESE CONDITIONS ARE SUFFICIENT TO CAUSE DAMAGE TO
SENSITIVE VEGETATION AND UNPROTECTED PLANTS.

CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. HOWEVER THERE ARE TWO
FACTORS GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD
BE THAT THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10
DEGREES. SECOND...THERE WILL BE TOO MUCH MIXING IN SOME OF THESE
AREAS DUE TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP
NEAR 10 OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS
MIGHT WANT TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE
30S. IT IS ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE
TO PENETRATE A BIT FURTHER SOUTHEAST...A FEW PARTS OF THIS
CORRIDOR OF COUNTIES COULD ALSO REQUIRE A FREEZE WARNING. THE
ONLY PLACES THAT SHOULD ESCAPE ANY FROST AND/OR FREEZE WILL BE THE
COASTAL SOUTHEAST GEORGIA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT TWO DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 18Z SUNDAY. BREEZY
WEST/NORTHWEST WINDS THIS AFTERNOON WILL DIMINISH BY THE
EVENING...EVENTUALLY BECOMING NORTH BEHIND A DRY COLD FRONT AFTER
MIDNIGHT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...WANING COLD ADVECTION AND A SLIGHT WEAKENING OF THE
PRESSURE GRADIENT HAS ALLOWED CONDITIONS TO IMPROVE OVER THE
WATERS. SMALL CRAFT ADVISORIES ARE NO LONGER IN EFFECT.

TONIGHT...THE IMPROVEMENT IN CONDITIONS WILL BE SHORT-LIVED AS A
STRENGTHENING CONTINENTAL HIGH BUILDS FROM THE OHIO VALLEY AND
EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE EVENING AND
OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER ROUND OF COLD
ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NORTHEAST SURGE
WILL OCCUR LATE. CONDITIONS COULD ACTUALLY APPROACH SMALL CRAFT
ADVISORY CRITERIA ON THE CHARLESTON COUNTY ATLANTIC WATERS AS
SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...WMS/
CLIMATE...




000
FXUS62 KCHS 281745
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
145 PM EDT SAT MAR 28 2015

.SYNOPSIS...
COLD CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...AN EXPANSIVE UPPER LEVEL TROUGH WILL REMAIN ANCHORED OVER
THE EASTERN UNITED STATES...WHILE STRONG HIGH PRESSURE CONTINUES
TO BUILD TOWARD THE EAST COAST. THIS PATTERN WILL SUPPORT RATHER
QUIET YET COLD CONDITIONS ACROSS THE FORECAST AREA TODAY.
SCATTERED MID LEVEL CLOUDS HAVE DEVELOPED ACROSS PORTIONS OF THE
FORECAST AREA BY EARLY AFTERNOON...HOWEVER EXPECT SKY COVER TO
REMAIN PARTLY CLOUDY OR LESS. HIGH TEMPERATURES WILL BE THE
COMBINED RESULT OF GRADUALLY WEAKENING COLD ADVECTION AND LOWER
HEIGHTS ALOFT...AS WELL AS THE WARMING EFFECTS OF A DOWNSLOPE FLOW
COMPONENT WITHIN WEST/NORTHWEST WINDS AND DECENT INSOLATION.
THUS...TEMPERATURES WILL PEAK ONLY IN THE UPPER 50S NORTH TO THE
LOW 60S SOUTH...10 TO 15 DEGREES BELOW SEASONAL NORMALS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF
THE LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT...WILL PUSH THROUGH THE REGION OVERNIGHT. THIS ALLOWS THE
UPSTREAM AND COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM
THE NORTHWEST WITH STEADILY RISING PRESSURES. IT ALSO ARRIVES
WITH ANOTHER INFLUX OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR
FREEZING TEMPS TO PENETRATE INTO AT LEAST THE NORTHWEST TIER.
AFTER COORDINATION WITH NEIGHBORING OFFICES...HAVE UPGRADED THE
EARLIER FREEZE WATCH TO A FREEZE WARNING FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS. THIS IS DUE
TO MIN TEMPS OF 30-32F FOR 3-5 HOURS LATE TONIGHT AND EARLY
SUNDAY...ALONG WITH PATCHY FROST. ALTHOUGH A HARD FREEZE IS NOT
EXPECTED...THESE CONDITIONS ARE SUFFICIENT TO CAUSE DAMAGE TO
SENSITIVE VEGETATION AND UNPROTECTED PLANTS.

CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. HOWEVER THERE ARE TWO
FACTORS GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD
BE THAT THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10
DEGREES. SECOND...THERE WILL BE TOO MUCH MIXING IN SOME OF THESE
AREAS DUE TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP
NEAR 10 OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS
MIGHT WANT TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE
30S. IT IS ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE
TO PENETRATE A BIT FURTHER SOUTHEAST...A FEW PARTS OF THIS
CORRIDOR OF COUNTIES COULD ALSO REQUIRE A FREEZE WARNING. THE
ONLY PLACES THAT SHOULD ESCAPE ANY FROST AND/OR FREEZE WILL BE THE
COASTAL SOUTHEAST GEORGIA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT TWO DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 18Z SUNDAY. BREEZY
WEST/NORTHWEST WINDS THIS AFTERNOON WILL DIMINISH BY THE
EVENING...EVENTUALLY BECOMING NORTH BEHIND A DRY COLD FRONT AFTER
MIDNIGHT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...WANING COLD ADVECTION AND A SLIGHT WEAKENING OF THE
PRESSURE GRADIENT HAS ALLOWED CONDITIONS TO IMPROVE OVER THE
WATERS. SMALL CRAFT ADVISORIES ARE NO LONGER IN EFFECT.

TONIGHT...THE IMPROVEMENT IN CONDITIONS WILL BE SHORT-LIVED AS A
STRENGTHENING CONTINENTAL HIGH BUILDS FROM THE OHIO VALLEY AND
EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE EVENING AND
OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER ROUND OF COLD
ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NORTHEAST SURGE
WILL OCCUR LATE. CONDITIONS COULD ACTUALLY APPROACH SMALL CRAFT
ADVISORY CRITERIA ON THE CHARLESTON COUNTY ATLANTIC WATERS AS
SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...WMS/
CLIMATE...





000
FXUS62 KCHS 281745
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
145 PM EDT SAT MAR 28 2015

.SYNOPSIS...
COLD CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...AN EXPANSIVE UPPER LEVEL TROUGH WILL REMAIN ANCHORED OVER
THE EASTERN UNITED STATES...WHILE STRONG HIGH PRESSURE CONTINUES
TO BUILD TOWARD THE EAST COAST. THIS PATTERN WILL SUPPORT RATHER
QUIET YET COLD CONDITIONS ACROSS THE FORECAST AREA TODAY.
SCATTERED MID LEVEL CLOUDS HAVE DEVELOPED ACROSS PORTIONS OF THE
FORECAST AREA BY EARLY AFTERNOON...HOWEVER EXPECT SKY COVER TO
REMAIN PARTLY CLOUDY OR LESS. HIGH TEMPERATURES WILL BE THE
COMBINED RESULT OF GRADUALLY WEAKENING COLD ADVECTION AND LOWER
HEIGHTS ALOFT...AS WELL AS THE WARMING EFFECTS OF A DOWNSLOPE FLOW
COMPONENT WITHIN WEST/NORTHWEST WINDS AND DECENT INSOLATION.
THUS...TEMPERATURES WILL PEAK ONLY IN THE UPPER 50S NORTH TO THE
LOW 60S SOUTH...10 TO 15 DEGREES BELOW SEASONAL NORMALS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF
THE LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT...WILL PUSH THROUGH THE REGION OVERNIGHT. THIS ALLOWS THE
UPSTREAM AND COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM
THE NORTHWEST WITH STEADILY RISING PRESSURES. IT ALSO ARRIVES
WITH ANOTHER INFLUX OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR
FREEZING TEMPS TO PENETRATE INTO AT LEAST THE NORTHWEST TIER.
AFTER COORDINATION WITH NEIGHBORING OFFICES...HAVE UPGRADED THE
EARLIER FREEZE WATCH TO A FREEZE WARNING FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS. THIS IS DUE
TO MIN TEMPS OF 30-32F FOR 3-5 HOURS LATE TONIGHT AND EARLY
SUNDAY...ALONG WITH PATCHY FROST. ALTHOUGH A HARD FREEZE IS NOT
EXPECTED...THESE CONDITIONS ARE SUFFICIENT TO CAUSE DAMAGE TO
SENSITIVE VEGETATION AND UNPROTECTED PLANTS.

CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. HOWEVER THERE ARE TWO
FACTORS GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD
BE THAT THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10
DEGREES. SECOND...THERE WILL BE TOO MUCH MIXING IN SOME OF THESE
AREAS DUE TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP
NEAR 10 OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS
MIGHT WANT TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE
30S. IT IS ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE
TO PENETRATE A BIT FURTHER SOUTHEAST...A FEW PARTS OF THIS
CORRIDOR OF COUNTIES COULD ALSO REQUIRE A FREEZE WARNING. THE
ONLY PLACES THAT SHOULD ESCAPE ANY FROST AND/OR FREEZE WILL BE THE
COASTAL SOUTHEAST GEORGIA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT TWO DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 18Z SUNDAY. BREEZY
WEST/NORTHWEST WINDS THIS AFTERNOON WILL DIMINISH BY THE
EVENING...EVENTUALLY BECOMING NORTH BEHIND A DRY COLD FRONT AFTER
MIDNIGHT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...WANING COLD ADVECTION AND A SLIGHT WEAKENING OF THE
PRESSURE GRADIENT HAS ALLOWED CONDITIONS TO IMPROVE OVER THE
WATERS. SMALL CRAFT ADVISORIES ARE NO LONGER IN EFFECT.

TONIGHT...THE IMPROVEMENT IN CONDITIONS WILL BE SHORT-LIVED AS A
STRENGTHENING CONTINENTAL HIGH BUILDS FROM THE OHIO VALLEY AND
EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE EVENING AND
OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER ROUND OF COLD
ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NORTHEAST SURGE
WILL OCCUR LATE. CONDITIONS COULD ACTUALLY APPROACH SMALL CRAFT
ADVISORY CRITERIA ON THE CHARLESTON COUNTY ATLANTIC WATERS AS
SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...WMS/
CLIMATE...





000
FXUS62 KCHS 281509
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1109 AM EDT SAT MAR 28 2015

.SYNOPSIS...
COLD CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...AN EXPANSIVE UPPER LEVEL TROUGH WILL REMAIN ANCHORED OVER
THE EASTERN UNITED STATES...WHILE STRONG HIGH PRESSURE CONTINUES
TO BUILD TOWARD THE EAST COAST. THIS PATTERN WILL SUPPORT RATHER
QUIET YET COLD CONDITIONS ACROSS THE FORECAST AREA TODAY.
TEMPERATURES AT 10 AM EDT ARE 15 TO 20 DEGREES COOLER THAN THIS
TIME YESTERDAY...DESPITE ABUNDANT SUNSHINE WITHIN MOSTLY CLEAR TO
PARTLY CLOUDY SKIES. SCATTERED MAINLY MID LEVEL CLOUDS HAVE
DEVELOPED ACROSS PORTIONS OF BERKELEY AND NORTHERN CHARLESTON
COUNTY LATE THIS MORNING...AND CANADIAN MODEL SIMULATED SATELLITE
SUGGESTS THAT SCATTERED CLOUDS COULD SPREAD SOUTHWARD AS THE DAY
PROGRESSES. HOWEVER...EXPECT SKY COVER TO REMAIN PARTLY CLOUDY OR
LESS THROUGH THE AFTERNOON. HIGH TEMPERATURES WILL BE THE
COMBINED RESULT OF GRADUALLY WEAKENING COLD ADVECTION AND LOWER
HEIGHTS ALOFT...AS WELL AS THE WARMING EFFECTS OF A DOWNSLOPE FLOW
COMPONENT WITHIN WEST/NORTHWEST WINDS AND DECENT INSOLATION.
THUS...TEMPERATURES WILL PEAK ONLY IN THE UPPER 50S NORTH TO THE
LOW 60S SOUTH...10 TO 15 DEGREES BELOW SEASONAL NORMALS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF
THE LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT...WILL PUSH THROUGH THE REGION OVERNIGHT. THIS ALLOWS THE
UPSTREAM AND COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM
THE NORTHWEST WITH STEADILY RISING PRESSURES. IT ALSO ARRIVES
WITH ANOTHER INFLUX OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR
FREEZING TEMPS TO PENETRATE INTO AT LEAST THE NORTHWEST TIER.
AFTER COORDINATION WITH NEIGHBORING OFFICES...HAVE UPGRADED THE
EARLIER FREEZE WATCH TO A FREEZE WARNING FROM INLAND BERKELEY
COUNTY TO ALLENDALE AND HAMPTON...SCREVEN AND JENKINS. THIS IS DUE
TO MIN TEMPS OF 30-32F FOR 3-5 HOURS LATE TONIGHT AND EARLY
SUNDAY...ALONG WITH PATCHY FROST. ALTHOUGH A HARD FREEZE IS NOT
EXPECTED...THESE CONDITIONS ARE SUFFICIENT TO CAUSE DAMAGE TO
SENSITIVE VEGETATION AND UNPROTECTED PLANTS.

CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. HOWEVER THERE ARE TWO
FACTORS GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD
BE THAT THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10
DEGREES. SECOND...THERE WILL BE TOO MUCH MIXING IN SOME OF THESE
AREAS DUE TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP
NEAR 10 OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS
MIGHT WANT TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE
30S. IT IS ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE
TO PENETRATE A BIT FURTHER SOUTHEAST...A FEW PARTS OF THIS
CORRIDOR OF COUNTIES COULD ALSO REQUIRE A FREEZE WARNING. THE
ONLY PLACES THAT SHOULD ESCAPE ANY FROST AND/OR FREEZE WILL BE THE
COASTAL SOUTHEAST GEORGIA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT TWO DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS THROUGH 12Z SUNDAY. WEST/NORTHWEST WINDS COULD
BECOME BREEZY TO GUSTY THIS AFTERNOON WITHIN DEEPER
MIXING...ESPECIALLY AT KSAV WHERE SPEEDS COULD PEAK AROUND 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...LATEST BUOY REPORTS AND COASTAL OBSERVATIONS SUPPORT
EXPIRING THE SMALL CRAFT ADVISORY FOR THE NEARSHORE GEORGIA
WATERS AT 11 AM EDT. THE OFFSHORE GEORGIA WATERS WILL CONTINUE IN
AN ADVISORY UNTIL 1 PM...WITH GUSTS TO 25 KT AND SEAS UP TO 6 FT
BETWEEN 40 AND 60 NM. CONDITIONS WILL STEADILY IMPROVE AS THE
AFTERNOON PROGRESSES AND COLD ADVECTION WANES.

TONIGHT...THE IMPROVEMENT IN CONDITIONS WILL BE SHORT-LIVED AS A
STRENGTHENING CONTINENTAL HIGH BUILDS FROM THE OHIO VALLEY AND
EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE EVENING AND
OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER ROUND OF COLD
ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NORTHEAST SURGE
WILL OCCUR LATE. CONDITIONS COULD ACTUALLY APPROACH SMALL CRAFT
ADVISORY CRITERIA ON THE CHARLESTON COUNTY ATLANTIC WATERS AS
SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR
         AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...WMS/
CLIMATE...




000
FXUS62 KCHS 281131
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
731 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS/PATCHY ALTOCUMULUS FROM
THE WEST AND FEW-SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE
INSOLATION TODAY. THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE
APPALACHIANS...WILL NEGATE A LITTLE OF THE COLDER AIR...BUT
SUPPORTIVE OF MAX TEMPS ONLY IN THE MID AND UPPER 50S FAR NORTH
AND NW TO THE LOWER 60S SOUTH. THIS IS SOME 10-13 DEGREES BELOW
SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. BUT THERE ARE TWO FACTORS
GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT
THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND
SECONDLY THERE WILL BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE
TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10
OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT
TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S. IT/S
ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE TO PENETRATE
A BIT FURTHER SE THAT A FEW PARTS OF THIS CORRIDOR OF COUNTIES MAY
ALSO REQUIRE A FREEZE WARNING. THE ONLY PLACES THAT SHOULD ESCAPE
ANY FROST AND/OR FREEZE WILL BE THE COASTAL SE GA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 12Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON.

KSAV...VFR THROUGH 12Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 281131
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
731 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS/PATCHY ALTOCUMULUS FROM
THE WEST AND FEW-SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE
INSOLATION TODAY. THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE
APPALACHIANS...WILL NEGATE A LITTLE OF THE COLDER AIR...BUT
SUPPORTIVE OF MAX TEMPS ONLY IN THE MID AND UPPER 50S FAR NORTH
AND NW TO THE LOWER 60S SOUTH. THIS IS SOME 10-13 DEGREES BELOW
SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. BUT THERE ARE TWO FACTORS
GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT
THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND
SECONDLY THERE WILL BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE
TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10
OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT
TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S. IT/S
ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE TO PENETRATE
A BIT FURTHER SE THAT A FEW PARTS OF THIS CORRIDOR OF COUNTIES MAY
ALSO REQUIRE A FREEZE WARNING. THE ONLY PLACES THAT SHOULD ESCAPE
ANY FROST AND/OR FREEZE WILL BE THE COASTAL SE GA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 12Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON.

KSAV...VFR THROUGH 12Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 281131
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
731 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS/PATCHY ALTOCUMULUS FROM
THE WEST AND FEW-SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE
INSOLATION TODAY. THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE
APPALACHIANS...WILL NEGATE A LITTLE OF THE COLDER AIR...BUT
SUPPORTIVE OF MAX TEMPS ONLY IN THE MID AND UPPER 50S FAR NORTH
AND NW TO THE LOWER 60S SOUTH. THIS IS SOME 10-13 DEGREES BELOW
SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. BUT THERE ARE TWO FACTORS
GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT
THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND
SECONDLY THERE WILL BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE
TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10
OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT
TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S. IT/S
ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE TO PENETRATE
A BIT FURTHER SE THAT A FEW PARTS OF THIS CORRIDOR OF COUNTIES MAY
ALSO REQUIRE A FREEZE WARNING. THE ONLY PLACES THAT SHOULD ESCAPE
ANY FROST AND/OR FREEZE WILL BE THE COASTAL SE GA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 12Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON.

KSAV...VFR THROUGH 12Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 281131
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
731 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS/PATCHY ALTOCUMULUS FROM
THE WEST AND FEW-SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE
INSOLATION TODAY. THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE
APPALACHIANS...WILL NEGATE A LITTLE OF THE COLDER AIR...BUT
SUPPORTIVE OF MAX TEMPS ONLY IN THE MID AND UPPER 50S FAR NORTH
AND NW TO THE LOWER 60S SOUTH. THIS IS SOME 10-13 DEGREES BELOW
SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. BUT THERE ARE TWO FACTORS
GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT
THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND
SECONDLY THERE WILL BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE
TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10
OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT
TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S. IT/S
ALSO CONCEIVABLE THAT IF THE FREEZING TEMPS ARE ABLE TO PENETRATE
A BIT FURTHER SE THAT A FEW PARTS OF THIS CORRIDOR OF COUNTIES MAY
ALSO REQUIRE A FREEZE WARNING. THE ONLY PLACES THAT SHOULD ESCAPE
ANY FROST AND/OR FREEZE WILL BE THE COASTAL SE GA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 12Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON.

KSAV...VFR THROUGH 12Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 281042
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
642 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS/PATCHY ALTOCUMULUS FROM
THE WEST AND FEW-SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE
INSOLATION TODAY. THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE
APPALACHIANS...WILL NEGATE A LITTLE OF THE COLDER AIR...BUT
SUPPORTIVE OF MAX TEMPS ONLY IN THE MID AND UPPER 50S FAR NORTH
AND NW TO THE LOWER 60S SOUTH. THIS IS SOME 10-13 DEGREES BELOW
SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. BUT THERE ARE TWO FACTORS
GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT
THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND
SECONDLY THERE WILL BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE
TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10
OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT
TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S. IT/S
ALSO CONCEIVABLY THAT IF THE FREEZING TEMPS ARE ABLE TO PENETRATE
A BIT FURTHER SE THAT A FEW PARTS OF THIS CORRIDOR OF COUNTIES MAY
ALSO REQUIRE A FREEZE WARNING. THE ONLY PLACES THAT SHOULD ESCAPE
ANY FROST AND/OR FREEZE WILL BE THE COASTAL SE GA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 06Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON AND THIS WILL BE ADDRESSED IN UPCOMING
TAF ISSUANCES.

KSAV...VFR THROUGH 06Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...




000
FXUS62 KCHS 281042
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
642 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS/PATCHY ALTOCUMULUS FROM
THE WEST AND FEW-SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE
INSOLATION TODAY. THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE
APPALACHIANS...WILL NEGATE A LITTLE OF THE COLDER AIR...BUT
SUPPORTIVE OF MAX TEMPS ONLY IN THE MID AND UPPER 50S FAR NORTH
AND NW TO THE LOWER 60S SOUTH. THIS IS SOME 10-13 DEGREES BELOW
SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER...TATTNALL AND LONG COUNTIES. BUT THERE ARE TWO FACTORS
GOING AGAINST ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT
THE DEW POINT DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND
SECONDLY THERE WILL BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE
TO THE HIGH BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10
OR 15 KT. EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT
TO TAKE PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S. IT/S
ALSO CONCEIVABLY THAT IF THE FREEZING TEMPS ARE ABLE TO PENETRATE
A BIT FURTHER SE THAT A FEW PARTS OF THIS CORRIDOR OF COUNTIES MAY
ALSO REQUIRE A FREEZE WARNING. THE ONLY PLACES THAT SHOULD ESCAPE
ANY FROST AND/OR FREEZE WILL BE THE COASTAL SE GA ZONES.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 06Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON AND THIS WILL BE ADDRESSED IN UPCOMING
TAF ISSUANCES.

KSAV...VFR THROUGH 06Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...
RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
CLIMATE...





000
FXUS62 KCHS 280801
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
401 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...A POTENT SHORT WAVE IS ROUNDING THE BASE OF
THE LARGER SCALE TROUGH ALOFT AND WILL PROVIDE PARTS OF THE
CHARLESTON QUAD-COUNTY DISTRICT WITH A FEW SHOWERS PRIOR TO
DAYBREAK. OTHERWISE WE/LL START THE DAY SOME 20-25 DEGREES COLDER
THAN THIS TIME YESTERDAY.

FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS FROM THE WEST AND FEW-
SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE INSOLATION TODAY.
THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE APPALACHIANS...WILL
NEGATE A LITTLE OF THE COLDER AIR...BUT SUPPORTIVE OF MAX TEMPS
ONLY IN THE MID AND UPPER 50S FAR NORTH AND NW TO THE LOWER 60S
SOUTH. THIS IS SOME 10-13 DEGREES BELOW SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER AND LONG COUNTIES. BUT THERE ARE TWO FACTORS GOING AGAINST
ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT THE DEW POINT
DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND SECONDLY THERE WILL
BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE TO THE HIGH
BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10 OR 15 KT.
EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT TO TAKE
PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 06Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON AND THIS WILL BE ADDRESSED IN UPCOMING
TAF ISSUANCES.

KSAV...VFR THROUGH 06Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...

RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...




000
FXUS62 KCHS 280801
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
401 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...A POTENT SHORT WAVE IS ROUNDING THE BASE OF
THE LARGER SCALE TROUGH ALOFT AND WILL PROVIDE PARTS OF THE
CHARLESTON QUAD-COUNTY DISTRICT WITH A FEW SHOWERS PRIOR TO
DAYBREAK. OTHERWISE WE/LL START THE DAY SOME 20-25 DEGREES COLDER
THAN THIS TIME YESTERDAY.

FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS FROM THE WEST AND FEW-
SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE INSOLATION TODAY.
THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE APPALACHIANS...WILL
NEGATE A LITTLE OF THE COLDER AIR...BUT SUPPORTIVE OF MAX TEMPS
ONLY IN THE MID AND UPPER 50S FAR NORTH AND NW TO THE LOWER 60S
SOUTH. THIS IS SOME 10-13 DEGREES BELOW SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER AND LONG COUNTIES. BUT THERE ARE TWO FACTORS GOING AGAINST
ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT THE DEW POINT
DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND SECONDLY THERE WILL
BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE TO THE HIGH
BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10 OR 15 KT.
EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT TO TAKE
PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 06Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON AND THIS WILL BE ADDRESSED IN UPCOMING
TAF ISSUANCES.

KSAV...VFR THROUGH 06Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...

RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...





000
FXUS62 KCHS 280801
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
401 AM EDT SAT MAR 28 2015

.SYNOPSIS...
CHILLY CONTINENTAL HIGH PRESSURE WILL PREVAIL INTO SUNDAY. WEAK
COLD FRONTS WILL PUSH INTO THE REGION LATE MONDAY AND AGAIN
WEDNESDAY...AND BOTH FRONTS SHOULD DISSIPATE OVER OR CLOSE TO THE
AREA. WARMER ATLANTIC HIGH PRESSURE WILL THEN BUILD OVER THE
REGION THROUGH LATE WEEK. A STRONGER COLD FRONT WILL ARRIVE LATE
WEEK OR EARLY NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...A POTENT SHORT WAVE IS ROUNDING THE BASE OF
THE LARGER SCALE TROUGH ALOFT AND WILL PROVIDE PARTS OF THE
CHARLESTON QUAD-COUNTY DISTRICT WITH A FEW SHOWERS PRIOR TO
DAYBREAK. OTHERWISE WE/LL START THE DAY SOME 20-25 DEGREES COLDER
THAN THIS TIME YESTERDAY.

FOR TODAY...A HIGHLY ANOMALOUS LONG WAVE TROUGH THAT IS SOME 2 TO
3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE MARCH WILL
REMAIN ANCHORED OVER THE EASTERN THIRD OF THE COUNTRY. AT THE
SURFACE WE FIND AN INTENSE 996 MB LOW LIFTING NE FROM OFF THE MID
ATLANTIC REGION EARLY TO EAST/SE OF NEW ENGLAND THIS
AFTERNOON...WHILE UPSTREAM A COLD 1027 MB HIGH WILL STRETCH FROM
THE WESTERN GREAT LAKES TO THE GULF OF MEXICO. THIS WILL PROVIDE
THE AREA WITH DRY AND STABLE CONDITIONS WITH A RATHER COOL WEST/NW
SYNOPTIC FLOW TO PREVAIL. THE RESULTING 850 MB TEMPS WILL BE
AROUND 2 STANDARD DEVIATIONS BELOW NORMAL...AS COLD AS -3C SOUTH
AND -5C NORTH. ASIDE FROM SOME THIN CIRRUS FROM THE WEST AND FEW-
SCATTERED FLAT CUMULUS...THERE IS CONSIDERABLE INSOLATION TODAY.
THAT ALONG WITH DOWNSLOPE TRAJECTORIES OFF THE APPALACHIANS...WILL
NEGATE A LITTLE OF THE COLDER AIR...BUT SUPPORTIVE OF MAX TEMPS
ONLY IN THE MID AND UPPER 50S FAR NORTH AND NW TO THE LOWER 60S
SOUTH. THIS IS SOME 10-13 DEGREES BELOW SEASONAL NORMS.

TONIGHT...COLD ADVECTION BECOMES MORE NEUTRAL TONIGHT AS THE
THERMAL TROUGH SHIFTS INTO THE ATLANTIC. HOWEVER...THE AXIS OF THE
LOW AND MID LEVEL TROUGH...ACTING ALMOST LIKE A SECONDARY COLD
FRONT WILL PUSH THROUGH OVERNIGHT. THIS ALLOWS THE UPSTREAM AND
COLD SURFACE HIGH IN THE OHIO VALLEY TO BUILD FROM THE NW WITH
STEADILY RISING PRESSURES. BUT IT ALSO ARRIVES WITH ANOTHER INFLUX
OF COLD CANADIAN AIR...ENOUGH TO ALLOW FOR FREEZING TEMPS TO
PENETRATE INTO AT LEAST OUR NW TIER. AFTER COORDINATION WITH
NEIGHBORING OFFICES WE HAVE UPGRADED THE EARLIER FREEZE WATCH TO A
FREEZE WARNING FROM INLAND BERKELEY COUNTY TO ALLENDALE AND
HAMPTON...SCREVEN AND JENKINS. THIS IS DUE TO MIN TEMPS OF 30-32F
FOR 3-5 HOURS LATE TONIGHT AND EARLY SUNDAY...ALONG WITH PATCHY
FROST. FORTUNATELY IT WON/T BE A HARD FREEZE...BUT THESE
CONDITIONS ARE ENOUGH TO CAUSE DAMAGE TO TENDER AND SENSITIVE
VEGETATION AND UNPROTECTED PLANTS.

WE CONSIDERED A FROST ADVISORY FROM INLAND CHARLESTON TO INLAND
JASPER IN SC AND THEN SOUTH/SW THROUGH INLAND CHATHAM...TO
CANDLER AND LONG COUNTIES. BUT THERE ARE TWO FACTORS GOING AGAINST
ANYTHING MORE THAN PATCHY FROST. FIRST WOULD BE THAT THE DEW POINT
DEPRESSIONS ARE QUITE LARGE...SOME 6-10F. AND SECONDLY THERE WILL
BE TOO MUCH MIXING IN SOME OF THESE AREAS DUE TO THE HIGH
BUILDING IN AND GEOSTROPHIC WINDS HOLDING UP NEAR 10 OR 15 KT.
EVEN SO...THOSE WITH FROST SENSITIVE PLANTS MIGHT WANT TO TAKE
PRECAUTIONS AS WELL...WITH LOWS IN THE MIDDLE 30S.

LOWS TONIGHT WILL BE VERY CLOSE TO RECORDS FOR MARCH 29...COMING
WITHIN ABOUT 2 DEGREES AT THE THREE CLIMATE SITES. SEE CLIMATE
SECTION BELOW FOR MORE INFORMATION.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE SURFACE HIGH WILL SHIFT OVER THE AREA. STRONG
SUBSIDENCE WILL PROVIDE A DRY AND SUNNY DAY. DESPITE FULL
INSOLATION...AFTER A COLD START TEMPERATURES WILL ONLY RECOVER INTO
THE UPPER 50S ACROSS MOST OF SE SC TO THE LOWER 60S ACROSS MUCH OF
SE GA. THESE TEMPERATURES WILL AVERAGE SOME 10 TO 13F BELOW NORMAL
FOR LATE MARCH.

SUNDAY NIGHT WILL START WITH MAINLY CLEAR SKIES/LIGHT
WINDS...SUPPORTING EXCELLENT RADIATIONAL COOLING CONDITIONS.
THEN...AS THE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE SHIFTING SOUTH
OF THE REGION AND A COLD FRONT APPROACHING FROM THE NORTHWEST...AND
AS CLOUDS BEGIN TO INCREASE...OVERNIGHT TEMPERATURES COULD HOLD
STEADY OR EVEN BEGIN TO RISE. THUS...HOURLY TEMPERATURES INDICATE
LOWS WITHIN A COUPLE OF HOURS OF MIDNIGHT...PERHAPS DIPPING INTO THE
UPPER 30S AT INLAND LOCATIONS BUT IN THE LOWER TO MID 40S MOST
LOCATIONS...FOLLOWED BY SLIGHTLY HIGHER TEMPS AROUND DAYBREAK
MONDAY. IF THIS SCENARIO IS DELAYED...LOWER TEMPS AND EVEN A TOUCH
OF FROST CANNOT BE RULED OUT WELL INLAND.

MONDAY...GUIDANCE HAS TRENDED TOWARD AN EARLIER ARRIVAL OF A COLD
FRONT FROM THE NORTHWEST...DUE IN PART TO A FAST-MOVING SHORTWAVE
TROUGH ALOFT WHICH WILL PASS NORTH OF THE REGION. GUIDANCE DEPICTS
SUFFICIENT FORCING FOR ASCENT AND ASSOCIATED DEEP LAYERED MOISTURE
TO JUSTIFY CHANCE POPS ADVANCING FROM N/NW TO S/SE AS THE DAY
PROGRESSES. ALSO...ISOLATED THUNDERSTORMS CANNOT BE RULED OUT...BUT
LATEST GUIDANCE SUGGESTS THAT A PLUME OF ENHANCED LOW-LEVEL
INSTABILITY WILL BE CUT OFF WEST OF THE FORECAST AREA...LEAVING ONLY
WEAK INSTABILITY IN PLACE OVER THE REGION. THUS...MAINTAINED NO
MENTION OF THUNDERSTORMS FOR NOW...BUT WILL CONTINUE TO ASSESS.
OTHERWISE...DESPITE CLOUD COVER COMPRESSIONAL HEATING AHEAD OF THE
COLD FRONT WILL HELP TEMPERATURES RECOVER INTO THE MID/UPPER 60S
NORTH AND LOWER TO MID 70S SOUTH...CLOSER TO NORMAL FOR LATE MARCH.

MONDAY NIGHT AND TUESDAY...THE COLD FRONT WILL WEAKEN...STALL AND
BEGIN TO DISSIPATE OVER OR CLOSE TO SOUTHERN COUNTIES OF THE
FORECAST AREA. MODEL SOLUTIONS DIFFER REGARDING THE SOUTHWARD
PROGRESS OF THE FRONT AND THE ASSOCIATED POOL OF ENHANCED MOISTURE.
PER LATEST TRENDS...SLIGHT CHANCE POPS ARE JUSTIFIED MONDAY NIGHT
THROUGH TUESDAY ACROSS SOUTHERN COUNTIES. OTHERWISE...LOWS IN THE
40S/50S MONDAY NIGHT WILL GIVE WAY TO NEAR-NORMAL TEMPERATURES
MAINLY IN THE 70S AWAY FROM THE COAST TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THROUGH LATE WEEK...ABOVE NORMAL TEMPERATURES WILL PREVAIL... EXCEPT
PERHAPS THURSDAY IF SHOWERS/THUNDERSTORMS BECOME MORE WIDESPREAD
THAN CURRENTLY FORECAST. THEN...NORMAL TO BELOW-NORMAL TEMPERATURES
SHOULD RETURN NEXT WEEKEND.

ANOTHER COLD FRONT IS EXPECTED TO SETTLE INTO THE REGION FROM THE
NORTH WEDNESDAY. DISCOUNTING THE 28/00 UTC CANADIAN SOLUTION
DEPICTING A PROGRESSIVE FRONT FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE N/NE...THIS FRONT SHOULD REMAIN WEAK AND WILL
LIKELY STALL AND DISSIPATE OVER OR CLOSE TO THE REGION. MEANWHILE...
A SHORTWAVE TROUGH ALOFT WILL ADVANCE THROUGH THE LOWER MS RIVER
VALLEY TOWARD THE NORTHERN GULF COAST...AND TO VARYING DEGREES
GUIDANCE DEPICTS AN EXPANDING PLUME OF MOISTURE/PRECIPITATION AHEAD
OF THIS FEATURE. GIVE THE SHORTWAVE RIDGING ALOFT OVER THE
REGION...FEEL THAT GUIDANCE COULD BE PUSHING CONVECTIVE PRECIPITATION
TOO QUICKLY TOWARD THE EAST/INTO THE REGION. THUS...HELD POPS BELOW
15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY...BUT FORECAST
CONFIDENCE IS LOW. A BETTER CHANCE FOR SHOWERS AND PERHAPS
THUNDERSTORMS SHOULD DEVELOP WEDNESDAY NIGHT THROUGH AT LEAST
THURSDAY NIGHT AS THE UPPER TROUGH PASSES OVER THE REGION. A
STRONGER COLD FRONT WILL ARRIVE LATER FRIDAY OR SATURDAY...
JUSTIFYING AT LEAST CHANCE POPS AND A MENTION THUNDERSTORMS.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
KCHS...VFR CONDITIONS THROUGH 06Z SUNDAY. NW WINDS MAY BECOME A
LITTLE GUSTY THIS AFTERNOON AND THIS WILL BE ADDRESSED IN UPCOMING
TAF ISSUANCES.

KSAV...VFR THROUGH 06Z SUNDAY. WEST/NW WINDS WILL BE GUSTY THIS
AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20 KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...COLD ADVECTION AND STEADY ISALLOBARIC PRESSURE RISES WILL
RESULT IN A CONTINUATION OF THE SMALL CRAFT ADVISORIES ACROSS THE
GA WATERS OUT 60 NM WHERE THE BEST LOW LEVEL JETTING WILL TAKE
PLACE. ELSEWHERE ACROSS THE MARINE COMMUNITY WE/LL REMAIN JUST
BELOW ADVISORY THRESHOLDS. CONDITIONS WILL IMPROVE THIS AFTERNOON
AS COLD ADVECTION WANES...PRESSURE RISES STOP AND THE PRESSURE
PATTERN BECOMES MORE RELAXED.

TONIGHT...THE IMPROVEMENT IN CONDITIONS FROM EARLIER WILL BE
SHORT-LIVED AS A STRENGTHENING CONTINENTAL HIGH BUILDS FORM THE
OHIO VALLEY AND EXPANDS ACROSS THE LOCAL WATERS DURING THE LATE
EVENING AND OVERNIGHT. IT WILL ALSO ARRIVE WITH ANOTHER SHOT OF
COLD ADVECTION AND PRESSURE RISES...AND A DECENT NORTH/NE SURGE
WILL OCCUR LATE. WE MAY ACTUALLY FLIRT WITH SMALL CRAFT ADVISORIES
ON THE CHARLESTON COUNTY ATLANTIC WATERS AS SUNRISE APPROACHES.

SUNDAY THROUGH THURSDAY...A SURGE OF NORTHEAST WINDS AND LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS COULD PERSIST INTO SUNDAY MORNING...
THEN A MUCH WEAKER PRESSURE PATTERN AND SLACKENING WINDS/SUBSIDING
SEAS SHOULD DEVELOP SUNDAY AFTERNOON INTO SUNDAY EVENING.
THEN...AHEAD OF AN APPROACHING COLD FRONT LATER SUNDAY NIGHT THROUGH
MONDAY...SW WINDS WILL INCREASE AND SEAS WILL BUILD...PERHAPS
PUSHING TO SCA LEVELS ESPECIALLY ACROSS AMZ350 AND AMZ374. THE COLD
FRONT WILL STALL AND DISSIPATE BY TUESDAY...THEN ANOTHER WEAK COLD
FRONT WILL LIKELY STALL AND DISSIPATE IN THE AREA WEDNESDAY.
THUS...A RELATIVELY BENIGN PRESSURE PATTERN PRIMARILY GOVERNED BY
OFFSHORE HIGH PRESSURE SHOULD HOLD WINDS/SEAS BELOW SCA LEVELS UNTIL
LATE WEEK OR EARLY NEXT WEEKEND.

&&

.CLIMATE...

RECORD LOWS MARCH 29TH...
KCHS...32 SET IN 1969.
KSAV...33 SET IN 1955.
KCXM...37 SET IN 1982.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR GAZ087-088.
SC...FREEZE WARNING FROM 4 AM TO 9 AM EDT SUNDAY FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...




000
FXUS62 KCHS 280516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
116 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE TO CHANCE POPS ACROSS OUR NW AND NORTHERN
TIER OF ZONES UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER
TONIGHT. THE 00Z CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND
WE THINK ANY MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND
LIGHT AS A SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8
KFT. DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL
MIXED IN FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT
BISECTED BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...ANY LINGERING MVFR CEILINGS AND ISOLATED SHOWERS WILL PULL
AWAY OVERNIGHT...WITH VFR CONDITIONS TO RETURN AND PREVAIL THROUGH
06Z SUNDAY. NW WINDS MAY BECOME A LITTLE GUSTY SATURDAY AFTERNOON
AND THIS WILL BE ADDRESSED IN UPCOMING TAF ISSUANCES.

KSAV...VFR THROUGH 06Z SUNDAY. WEST/NW WINDS WILL BE GUSTY
SATURDAY AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20
KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT





000
FXUS62 KCHS 280516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
116 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE TO CHANCE POPS ACROSS OUR NW AND NORTHERN
TIER OF ZONES UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER
TONIGHT. THE 00Z CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND
WE THINK ANY MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND
LIGHT AS A SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8
KFT. DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL
MIXED IN FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT
BISECTED BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...ANY LINGERING MVFR CEILINGS AND ISOLATED SHOWERS WILL PULL
AWAY OVERNIGHT...WITH VFR CONDITIONS TO RETURN AND PREVAIL THROUGH
06Z SUNDAY. NW WINDS MAY BECOME A LITTLE GUSTY SATURDAY AFTERNOON
AND THIS WILL BE ADDRESSED IN UPCOMING TAF ISSUANCES.

KSAV...VFR THROUGH 06Z SUNDAY. WEST/NW WINDS WILL BE GUSTY
SATURDAY AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20
KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT




000
FXUS62 KCHS 280516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
116 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE TO CHANCE POPS ACROSS OUR NW AND NORTHERN
TIER OF ZONES UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER
TONIGHT. THE 00Z CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND
WE THINK ANY MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND
LIGHT AS A SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8
KFT. DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL
MIXED IN FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT
BISECTED BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...ANY LINGERING MVFR CEILINGS AND ISOLATED SHOWERS WILL PULL
AWAY OVERNIGHT...WITH VFR CONDITIONS TO RETURN AND PREVAIL THROUGH
06Z SUNDAY. NW WINDS MAY BECOME A LITTLE GUSTY SATURDAY AFTERNOON
AND THIS WILL BE ADDRESSED IN UPCOMING TAF ISSUANCES.

KSAV...VFR THROUGH 06Z SUNDAY. WEST/NW WINDS WILL BE GUSTY
SATURDAY AFTERNOON WITH DEEP MIXING TO OCCUR...PEAKING CLOSE TO 20
KT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT





000
FXUS62 KCHS 280447
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1247 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE TO CHANCE POPS ACROSS OUR NW AND NORTHERN
TIER OF ZONES UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER
TONIGHT. THE 00Z CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND
WE THINK ANY MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND
LIGHT AS A SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8
KFT. DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL
MIXED IN FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT
BISECTED BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...MVFR AND LOCAL IFR CIGS REMAIN LIKELY THE NEXT SEVERAL
HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED DRYING BEGINS TO
CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS OVERNIGHT BEFORE
WHOLESALE CLEARING LATE. VFR CONDITIONS WILL DEVELOP LATE
TONIGHT...THEN CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT





000
FXUS62 KCHS 280447
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1247 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE TO CHANCE POPS ACROSS OUR NW AND NORTHERN
TIER OF ZONES UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER
TONIGHT. THE 00Z CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND
WE THINK ANY MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND
LIGHT AS A SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8
KFT. DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL
MIXED IN FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT
BISECTED BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...MVFR AND LOCAL IFR CIGS REMAIN LIKELY THE NEXT SEVERAL
HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED DRYING BEGINS TO
CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS OVERNIGHT BEFORE
WHOLESALE CLEARING LATE. VFR CONDITIONS WILL DEVELOP LATE
TONIGHT...THEN CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT





000
FXUS62 KCHS 280447
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1247 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE TO CHANCE POPS ACROSS OUR NW AND NORTHERN
TIER OF ZONES UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER
TONIGHT. THE 00Z CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND
WE THINK ANY MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND
LIGHT AS A SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8
KFT. DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL
MIXED IN FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT
BISECTED BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...MVFR AND LOCAL IFR CIGS REMAIN LIKELY THE NEXT SEVERAL
HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED DRYING BEGINS TO
CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS OVERNIGHT BEFORE
WHOLESALE CLEARING LATE. VFR CONDITIONS WILL DEVELOP LATE
TONIGHT...THEN CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT




000
FXUS62 KCHS 280447
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1247 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE TO CHANCE POPS ACROSS OUR NW AND NORTHERN
TIER OF ZONES UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER
TONIGHT. THE 00Z CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND
WE THINK ANY MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND
LIGHT AS A SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8
KFT. DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL
MIXED IN FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT
BISECTED BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...MVFR AND LOCAL IFR CIGS REMAIN LIKELY THE NEXT SEVERAL
HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED DRYING BEGINS TO
CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS OVERNIGHT BEFORE
WHOLESALE CLEARING LATE. VFR CONDITIONS WILL DEVELOP LATE
TONIGHT...THEN CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT




000
FXUS62 KCHS 280446
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1246 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE POPS ACROSS OUR NORTHERN TIER OF ZONES
UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER TONIGHT. THE 00Z
CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND WE THINK ANY
MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND LIGHT AS A
SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8 KFT.
DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL MIXED IN
FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT BISECTED
BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...MVFR AND LOCAL IFR CIGS REMAIN LIKELY THE NEXT SEVERAL
HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED DRYING BEGINS TO
CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS OVERNIGHT BEFORE
WHOLESALE CLEARING LATE. VFR CONDITIONS WILL DEVELOP LATE
TONIGHT...THEN CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT




000
FXUS62 KCHS 280446
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1246 AM EDT SAT MAR 28 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACROSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE
MAINTAINED SLIGHT CHANCE POPS ACROSS OUR NORTHERN TIER OF ZONES
UNTIL THE UPPER LEVEL DISTURBANCE PASSES LATER TONIGHT. THE 00Z
CHARLESTON SOUNDING WAS BONE DRY ABOVE 850 MB AND WE THINK ANY
MEASURABLE RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND LIGHT AS A
SHALLOW LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8 KFT.
DESPITE THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL MIXED IN
FROM THE SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT BISECTED
BY AN AXIS SOME BETTER UPPER FORCING FOR ASCENT.

LATE EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX
MESOSCALE WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH
OF I-16 WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW
CLOUDS ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS
TRENDS STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR
ADVECTION REGIME ONGOING.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
KCHS...MVFR AND LOCAL IFR CIGS REMAIN LIKELY THE NEXT SEVERAL
HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED DRYING BEGINS TO
CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS OVERNIGHT BEFORE
WHOLESALE CLEARING LATE. VFR CONDITIONS WILL DEVELOP LATE
TONIGHT...THEN CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORY FOR THE OFFSHORE GEORGIA
ZONES REMAIN QUITE MARGINAL BUT HAVE BEEN MAINTAINED AS MODELS
INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND IMPROVING LOW
LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS. OFFSHORE JETTING
AND SURGING APPEARS TO BE INCREASING OVER THE GEORGIA WATERS PER
LATEST GRAYS REEF AND FORT PULASKI OBS. THE ADVISORIES ARE IN
EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT. SEAS 2 TO 4 FT
WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     GAZ087-088.
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT





000
FXUS62 KCHS 280147
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
947 PM EDT FRI MAR 27 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACOSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE MAINTAINED
SLIGHT CHANCE POPS ACROSS OUR NORTHERN TIER OF ZONES UNTIL THE
UPPER LEVEL DISTURBANCE PASSES LATER TONIGHT. THE 00Z CHARLESTON
SOUNDING WAS BONE DRY ABOVE 850 MB AND WE THINK ANY MEASURABLE
RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND LIGHT AS A SHALLOW
LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8 KFT. DESPITE
THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL MIXED IN FROM THE
SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT BISECTED BY AN
AXIS SOME BETTER UPPER FORCING FOR ASCENT.

EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX MESOSCALE
WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH OF I-16
WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW CLOUDS
ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS TRENDS
STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR ADVECTION
REGIME ONGOING.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
KCHS...PRIOR TO MIDNIGHT...MVFR AND LOCAL IFR CIGS REMAIN LIKELY
THE NEXT SEVERAL HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED
DRYING BEGINS TO CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS
OVERNIGHT BEFORE WHOLESALE CLEARING LATE. VFR CONDITIONS WILL
DEVELOP LATE TONIGHT...THEN CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON
COUNTY WATERS AND THE OFFSHORE GEORGIA ZONES REMAIN QUITE MARGINAL
BUT HAVE BEEN MAINTAINED OFF THE CHARLESTON COAST UNTIL 1 AM AS
MODELS INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND
IMPROVING LOW LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS.
OFFSHORE JETTING AND SURGING APPEARS TO BE INCREASING OVER THE
GEORGIA WATERS PER LATEST GRAYS REEF AND FORT PULASKI OBS. THE
ADVISORIES ARE IN EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT.
SEAS 2 TO 4 FT WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT SATURDAY FOR AMZ350.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...





000
FXUS62 KCHS 280147
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
947 PM EDT FRI MAR 27 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE WEST OVERNIGHT...THEN PREVAIL
THROUGH THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE
MONDAY INTO EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A
WARM FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MUCH COOLER AIR CONTINUES TO ADVECT ACROSS THE FORECAST AREA THIS
EVENING IN THE WAKE OF A SURFACE LOW AND ATTENDANT COLD FRONT
WHICH WERE NOW WELL OFFSHORE. A STRONG SHORTWAVE EMBEDDED WITHIN
A DEEP UPPER TROUGH WILL SHIFT EAST THROUGH THE REGION OVERNIGHT.
AREAS OF LIGHT RAIN WITH A FEW CONVECTIVE ELEMENTS HAVE REDEVELOPED
UPSTREAM ACOSS THE MIDLANDS OF SOUTH CAROLINA AND WE HAVE MAINTAINED
SLIGHT CHANCE POPS ACROSS OUR NORTHERN TIER OF ZONES UNTIL THE
UPPER LEVEL DISTURBANCE PASSES LATER TONIGHT. THE 00Z CHARLESTON
SOUNDING WAS BONE DRY ABOVE 850 MB AND WE THINK ANY MEASURABLE
RAINFALL AMOUNTS WILL MAINLY BE SPARSE AND LIGHT AS A SHALLOW
LAYER OF HIGHER RH VALUES POOL BETWEEN 4 AND 8 KFT. DESPITE
THIS...CANNOT RULE OUT SOME PATCHY LIGHT GRAUPEL MIXED IN FROM THE
SANTEE COOPER LAKES NORTH GIVEN COLD TEMPS ALOFT BISECTED BY AN
AXIS SOME BETTER UPPER FORCING FOR ASCENT.

EVENING UPDATES HAVE BEEN FOLLOWING TRENDS OF A COMPLEX MESOSCALE
WITH AN ARC OF STRONG LOW LEVEL DRYING ALONG AND SOUTH OF I-16
WITH CLEARING SKIES TO FALLING TEMPS AND WIDESPREAD LOW CLOUDS
ACROSS THE CHARLESTON TRI-COUNTY. OVERALL...MINIMUM TEMPS TRENDS
STILL ON TARGET WITH A SOLID/STEADY LOW LEVEL COLD AIR ADVECTION
REGIME ONGOING.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
KCHS...PRIOR TO MIDNIGHT...MVFR AND LOCAL IFR CIGS REMAIN LIKELY
THE NEXT SEVERAL HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED
DRYING BEGINS TO CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS
OVERNIGHT BEFORE WHOLESALE CLEARING LATE. VFR CONDITIONS WILL
DEVELOP LATE TONIGHT...THEN CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON
COUNTY WATERS AND THE OFFSHORE GEORGIA ZONES REMAIN QUITE MARGINAL
BUT HAVE BEEN MAINTAINED OFF THE CHARLESTON COAST UNTIL 1 AM AS
MODELS INDICATE AN UPTICK OF 1000 MB GEOSTROPHIC FLOW AND
IMPROVING LOW LEVEL MIXING ENVIRONMENTS OVER THE SHELF WATERS.
OFFSHORE JETTING AND SURGING APPEARS TO BE INCREASING OVER THE
GEORGIA WATERS PER LATEST GRAYS REEF AND FORT PULASKI OBS. THE
ADVISORIES ARE IN EFFECT FOR ALL OF THE GEORGIA WATERS OVERNIGHT.
SEAS 2 TO 4 FT WITHIN 20 NM AND 4 TO 6 FT WELL OFFSHORE.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT SATURDAY FOR AMZ350.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...




000
FXUS62 KCHS 272227
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
627 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL CONTINUE TO MOVE OFFSHORE EARLY THIS
EVENING...WITH UNSEASONABLY COLD HIGH PRESSURE PREVAILING THROUGH
THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM FRONT.
WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AROUND 6 PM...RADAR AND SURFACE OBS INDICATE THE A SHARP THERMAL
BOUNDARY BETWEEN BEAUFORT AND CHARLESTON WHERE TEMPS WERE NOW
IN THE MID 50S ACROSS THE CHS TRI-COUNTY. COOLER AIR WAS ALSO
BEGINNING TO FILTER INTO S GEORGIA AS MID LEVEL HEIGHTS FALL AHEAD
OF A DIGGING UPPER WAVE. THE EARLIER LINE OF CONVECTION WAS NOW
WELL OFF THE COAST AND MOST AREAS HAVE LIKELY SEEN THE END OF THE
RAIN. AN EXCEPTION COULD BE ACROSS NORTHERN SOUTH CAROLINA ZONES
WHERE SOME LIGHT SHOWERS REDEVELOP AHEAD OF THE APPROACH VORT. ON
THE EARLY EVENING UPDATE WE ATTEMPTED TO PORTRAY VERY NEAR TERM
TEMP TRENDS IN A COMPLEX MESOSCALE ENVIRONMENT. WE HAVE ENDED RAIN
CHANCES ALONG AND S OF I-16 AND TWEAKED SOME WIND TRENDS.

EXPECT THE MAJORITY OF THE FORECAST AREA TO BE FREE OF RAIN FOR
THE LATE EVENING AND OVERNIGHT TIME FRAME. THE EXCEPTION WILL BE
PORTIONS OF THE CHARLESTON TRI COUNTY REGION...WHERE STRONG
FORCING AS THE UPPER TROUGH PASSES OVER THE AREA CAN TAP INTO
LINGERING MOISTURE THAT SUPPORTS ISOLATED SHOWERS TONIGHT.
ALTHOUGH TEMPERATURES WILL QUICKLY FALL BEHIND THE FRONT THROUGH
THE EVENING/NIGHTTIME HOURS...LOWS WILL REMAIN ABOVE FREEZING AND
RANGE FROM AROUND 39 DEGREES FAR INLAND TO THE LOW 40S ELSEWHERE.
THUS...ANY LIGHT PRECIPITATION ACROSS NORTHERN AREAS OVERNIGHT
WILL BE IN THE FORM OF LIQUID RAIN. HOWEVER...STEEP MID LEVEL
LAPSE RATES AND VERY COLD AIR ALOFT COULD SUPPORT ISOLATED SOFT
HAIL OR GRAUPEL AS THE SHORT WAVE SWINGS THROUGH THE AREA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
KCHS...PRIOR TO MIDNIGHT...MVFR AND LOCAL IFR CIGS REMAIN LIKELY
THE NEXT SEVERAL HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED
DRYING BEGINS TO CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS
OVERNIGHT BEFORE WHOLESALE CLEARING LATE. VFR CONDITIONS WILL
DEVELOP EITHER LATER THIS EVENING OR EARLY IN THE OVERNIGHT...THEN
CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON COUNTY
WATERS AND THE OFFSHORE GEORGIA ZONES ARE QUITE MARGINAL BY LATE
AFTERNOON. PREFER TO KEEP THE ADVISORIES GOING AT THIS POINT
CONSIDERING THE PASSAGE OF A COLD FRONT IN THE NEXT FEW HOURS...AS
WELL AS POTENTIAL SURGING WITHIN A TIGHTENED GRADIENT AND ENHANCED
MIXING OVERNIGHT. AN ADDITIONAL ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WILL GO INTO EFFECT AT 11 PM EDT...AS THE SOUTHEAST GEORGIA
MARINE ZONES APPEAR TO FALL WITHIN THE TIGHTEST GRADIENT BETWEEN
THE EXITING FRONTAL TROUGH AND BUILDING INLAND SURFACE HIGH
PRESSURE. CRITERIA WILL MAINLY BE REACHED VIA FREQUENT GUSTS TO 25
KT.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT/WMS




000
FXUS62 KCHS 272227
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
627 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL CONTINUE TO MOVE OFFSHORE EARLY THIS
EVENING...WITH UNSEASONABLY COLD HIGH PRESSURE PREVAILING THROUGH
THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM FRONT.
WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AROUND 6 PM...RADAR AND SURFACE OBS INDICATE THE A SHARP THERMAL
BOUNDARY BETWEEN BEAUFORT AND CHARLESTON WHERE TEMPS WERE NOW
IN THE MID 50S ACROSS THE CHS TRI-COUNTY. COOLER AIR WAS ALSO
BEGINNING TO FILTER INTO S GEORGIA AS MID LEVEL HEIGHTS FALL AHEAD
OF A DIGGING UPPER WAVE. THE EARLIER LINE OF CONVECTION WAS NOW
WELL OFF THE COAST AND MOST AREAS HAVE LIKELY SEEN THE END OF THE
RAIN. AN EXCEPTION COULD BE ACROSS NORTHERN SOUTH CAROLINA ZONES
WHERE SOME LIGHT SHOWERS REDEVELOP AHEAD OF THE APPROACH VORT. ON
THE EARLY EVENING UPDATE WE ATTEMPTED TO PORTRAY VERY NEAR TERM
TEMP TRENDS IN A COMPLEX MESOSCALE ENVIRONMENT. WE HAVE ENDED RAIN
CHANCES ALONG AND S OF I-16 AND TWEAKED SOME WIND TRENDS.

EXPECT THE MAJORITY OF THE FORECAST AREA TO BE FREE OF RAIN FOR
THE LATE EVENING AND OVERNIGHT TIME FRAME. THE EXCEPTION WILL BE
PORTIONS OF THE CHARLESTON TRI COUNTY REGION...WHERE STRONG
FORCING AS THE UPPER TROUGH PASSES OVER THE AREA CAN TAP INTO
LINGERING MOISTURE THAT SUPPORTS ISOLATED SHOWERS TONIGHT.
ALTHOUGH TEMPERATURES WILL QUICKLY FALL BEHIND THE FRONT THROUGH
THE EVENING/NIGHTTIME HOURS...LOWS WILL REMAIN ABOVE FREEZING AND
RANGE FROM AROUND 39 DEGREES FAR INLAND TO THE LOW 40S ELSEWHERE.
THUS...ANY LIGHT PRECIPITATION ACROSS NORTHERN AREAS OVERNIGHT
WILL BE IN THE FORM OF LIQUID RAIN. HOWEVER...STEEP MID LEVEL
LAPSE RATES AND VERY COLD AIR ALOFT COULD SUPPORT ISOLATED SOFT
HAIL OR GRAUPEL AS THE SHORT WAVE SWINGS THROUGH THE AREA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
KCHS...PRIOR TO MIDNIGHT...MVFR AND LOCAL IFR CIGS REMAIN LIKELY
THE NEXT SEVERAL HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED
DRYING BEGINS TO CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS
OVERNIGHT BEFORE WHOLESALE CLEARING LATE. VFR CONDITIONS WILL
DEVELOP EITHER LATER THIS EVENING OR EARLY IN THE OVERNIGHT...THEN
CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON COUNTY
WATERS AND THE OFFSHORE GEORGIA ZONES ARE QUITE MARGINAL BY LATE
AFTERNOON. PREFER TO KEEP THE ADVISORIES GOING AT THIS POINT
CONSIDERING THE PASSAGE OF A COLD FRONT IN THE NEXT FEW HOURS...AS
WELL AS POTENTIAL SURGING WITHIN A TIGHTENED GRADIENT AND ENHANCED
MIXING OVERNIGHT. AN ADDITIONAL ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WILL GO INTO EFFECT AT 11 PM EDT...AS THE SOUTHEAST GEORGIA
MARINE ZONES APPEAR TO FALL WITHIN THE TIGHTEST GRADIENT BETWEEN
THE EXITING FRONTAL TROUGH AND BUILDING INLAND SURFACE HIGH
PRESSURE. CRITERIA WILL MAINLY BE REACHED VIA FREQUENT GUSTS TO 25
KT.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT/WMS





000
FXUS62 KCHS 272227
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
627 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL CONTINUE TO MOVE OFFSHORE EARLY THIS
EVENING...WITH UNSEASONABLY COLD HIGH PRESSURE PREVAILING THROUGH
THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM FRONT.
WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AROUND 6 PM...RADAR AND SURFACE OBS INDICATE THE A SHARP THERMAL
BOUNDARY BETWEEN BEAUFORT AND CHARLESTON WHERE TEMPS WERE NOW
IN THE MID 50S ACROSS THE CHS TRI-COUNTY. COOLER AIR WAS ALSO
BEGINNING TO FILTER INTO S GEORGIA AS MID LEVEL HEIGHTS FALL AHEAD
OF A DIGGING UPPER WAVE. THE EARLIER LINE OF CONVECTION WAS NOW
WELL OFF THE COAST AND MOST AREAS HAVE LIKELY SEEN THE END OF THE
RAIN. AN EXCEPTION COULD BE ACROSS NORTHERN SOUTH CAROLINA ZONES
WHERE SOME LIGHT SHOWERS REDEVELOP AHEAD OF THE APPROACH VORT. ON
THE EARLY EVENING UPDATE WE ATTEMPTED TO PORTRAY VERY NEAR TERM
TEMP TRENDS IN A COMPLEX MESOSCALE ENVIRONMENT. WE HAVE ENDED RAIN
CHANCES ALONG AND S OF I-16 AND TWEAKED SOME WIND TRENDS.

EXPECT THE MAJORITY OF THE FORECAST AREA TO BE FREE OF RAIN FOR
THE LATE EVENING AND OVERNIGHT TIME FRAME. THE EXCEPTION WILL BE
PORTIONS OF THE CHARLESTON TRI COUNTY REGION...WHERE STRONG
FORCING AS THE UPPER TROUGH PASSES OVER THE AREA CAN TAP INTO
LINGERING MOISTURE THAT SUPPORTS ISOLATED SHOWERS TONIGHT.
ALTHOUGH TEMPERATURES WILL QUICKLY FALL BEHIND THE FRONT THROUGH
THE EVENING/NIGHTTIME HOURS...LOWS WILL REMAIN ABOVE FREEZING AND
RANGE FROM AROUND 39 DEGREES FAR INLAND TO THE LOW 40S ELSEWHERE.
THUS...ANY LIGHT PRECIPITATION ACROSS NORTHERN AREAS OVERNIGHT
WILL BE IN THE FORM OF LIQUID RAIN. HOWEVER...STEEP MID LEVEL
LAPSE RATES AND VERY COLD AIR ALOFT COULD SUPPORT ISOLATED SOFT
HAIL OR GRAUPEL AS THE SHORT WAVE SWINGS THROUGH THE AREA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
KCHS...PRIOR TO MIDNIGHT...MVFR AND LOCAL IFR CIGS REMAIN LIKELY
THE NEXT SEVERAL HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED
DRYING BEGINS TO CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS
OVERNIGHT BEFORE WHOLESALE CLEARING LATE. VFR CONDITIONS WILL
DEVELOP EITHER LATER THIS EVENING OR EARLY IN THE OVERNIGHT...THEN
CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON COUNTY
WATERS AND THE OFFSHORE GEORGIA ZONES ARE QUITE MARGINAL BY LATE
AFTERNOON. PREFER TO KEEP THE ADVISORIES GOING AT THIS POINT
CONSIDERING THE PASSAGE OF A COLD FRONT IN THE NEXT FEW HOURS...AS
WELL AS POTENTIAL SURGING WITHIN A TIGHTENED GRADIENT AND ENHANCED
MIXING OVERNIGHT. AN ADDITIONAL ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WILL GO INTO EFFECT AT 11 PM EDT...AS THE SOUTHEAST GEORGIA
MARINE ZONES APPEAR TO FALL WITHIN THE TIGHTEST GRADIENT BETWEEN
THE EXITING FRONTAL TROUGH AND BUILDING INLAND SURFACE HIGH
PRESSURE. CRITERIA WILL MAINLY BE REACHED VIA FREQUENT GUSTS TO 25
KT.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT/WMS




000
FXUS62 KCHS 272227
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
627 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL CONTINUE TO MOVE OFFSHORE EARLY THIS
EVENING...WITH UNSEASONABLY COLD HIGH PRESSURE PREVAILING THROUGH
THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM FRONT.
WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AROUND 6 PM...RADAR AND SURFACE OBS INDICATE THE A SHARP THERMAL
BOUNDARY BETWEEN BEAUFORT AND CHARLESTON WHERE TEMPS WERE NOW
IN THE MID 50S ACROSS THE CHS TRI-COUNTY. COOLER AIR WAS ALSO
BEGINNING TO FILTER INTO S GEORGIA AS MID LEVEL HEIGHTS FALL AHEAD
OF A DIGGING UPPER WAVE. THE EARLIER LINE OF CONVECTION WAS NOW
WELL OFF THE COAST AND MOST AREAS HAVE LIKELY SEEN THE END OF THE
RAIN. AN EXCEPTION COULD BE ACROSS NORTHERN SOUTH CAROLINA ZONES
WHERE SOME LIGHT SHOWERS REDEVELOP AHEAD OF THE APPROACH VORT. ON
THE EARLY EVENING UPDATE WE ATTEMPTED TO PORTRAY VERY NEAR TERM
TEMP TRENDS IN A COMPLEX MESOSCALE ENVIRONMENT. WE HAVE ENDED RAIN
CHANCES ALONG AND S OF I-16 AND TWEAKED SOME WIND TRENDS.

EXPECT THE MAJORITY OF THE FORECAST AREA TO BE FREE OF RAIN FOR
THE LATE EVENING AND OVERNIGHT TIME FRAME. THE EXCEPTION WILL BE
PORTIONS OF THE CHARLESTON TRI COUNTY REGION...WHERE STRONG
FORCING AS THE UPPER TROUGH PASSES OVER THE AREA CAN TAP INTO
LINGERING MOISTURE THAT SUPPORTS ISOLATED SHOWERS TONIGHT.
ALTHOUGH TEMPERATURES WILL QUICKLY FALL BEHIND THE FRONT THROUGH
THE EVENING/NIGHTTIME HOURS...LOWS WILL REMAIN ABOVE FREEZING AND
RANGE FROM AROUND 39 DEGREES FAR INLAND TO THE LOW 40S ELSEWHERE.
THUS...ANY LIGHT PRECIPITATION ACROSS NORTHERN AREAS OVERNIGHT
WILL BE IN THE FORM OF LIQUID RAIN. HOWEVER...STEEP MID LEVEL
LAPSE RATES AND VERY COLD AIR ALOFT COULD SUPPORT ISOLATED SOFT
HAIL OR GRAUPEL AS THE SHORT WAVE SWINGS THROUGH THE AREA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
KCHS...PRIOR TO MIDNIGHT...MVFR AND LOCAL IFR CIGS REMAIN LIKELY
THE NEXT SEVERAL HOURS AND POSSIBLY TO BEFORE STRONG DEEP LAYERED
DRYING BEGINS TO CLEAR SKIES. CANNOT RULE OUT ISOLATED SHOWERS
OVERNIGHT BEFORE WHOLESALE CLEARING LATE. VFR CONDITIONS WILL
DEVELOP EITHER LATER THIS EVENING OR EARLY IN THE OVERNIGHT...THEN
CONTINUE UNTIL 00Z SUNDAY.

KSAV...LOWER LEVELS ARE DRIER AND WITH WNW FLOW...LOW CIGS SHOULD
REMAIN NORTH OF THE TERMINAL THIS EVENING. VFR CONDITIONS WILL
PERSIST UNTIL 00Z SUNDAY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON COUNTY
WATERS AND THE OFFSHORE GEORGIA ZONES ARE QUITE MARGINAL BY LATE
AFTERNOON. PREFER TO KEEP THE ADVISORIES GOING AT THIS POINT
CONSIDERING THE PASSAGE OF A COLD FRONT IN THE NEXT FEW HOURS...AS
WELL AS POTENTIAL SURGING WITHIN A TIGHTENED GRADIENT AND ENHANCED
MIXING OVERNIGHT. AN ADDITIONAL ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WILL GO INTO EFFECT AT 11 PM EDT...AS THE SOUTHEAST GEORGIA
MARINE ZONES APPEAR TO FALL WITHIN THE TIGHTEST GRADIENT BETWEEN
THE EXITING FRONTAL TROUGH AND BUILDING INLAND SURFACE HIGH
PRESSURE. CRITERIA WILL MAINLY BE REACHED VIA FREQUENT GUSTS TO 25
KT.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...
MARINE...ECT/WMS





000
FXUS62 KCHS 272030
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
430 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL PASS OFF THE COAST EARLY THIS
EVENING...WITH UNSEASONABLY COLD HIGH PRESSURE PREVAILING THROUGH
THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM FRONT.
WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE MAIN LINE OF CONVECTION IS QUICKLY MOVING OFF THE COASTLINE
BY LATE AFTERNOON...WHILE ISOLATED TO SCATTERED SHOWERS HAVE
DEVELOPED IN ITS WAKE ACROSS THE NORTHERN SOUTH CAROLINA COUNTIES.
THE LOCATION OF THE COLD FRONT IS VERY DISTINCT WHEN EXAMINING
WIND REPORTS ACROSS THE REGION...WITH WIND DIRECTIONS HAVING
QUICKLY VEERED TO THE NORTH BEHIND THE DESCENDING FRONT. THE COLD
FRONT WILL STEADILY SHIFT THROUGH THE FORECAST AREA...ASSISTED IN
ITS PROGRESSION BY STRONG SHORTWAVE ENERGY DOWNSTREAM OF AN
AMPLIFYING UPPER TROUGH AXIS SWINGING EAST TOWARD THE AREA.

DRIER AIR WILL BE QUICKLY FILTERING INTO THE REGION DURING THE
NEXT SEVERAL HOURS...AND EXPECT THE MAJORITY OF THE FORECAST AREA
TO BE FREE OF RAIN FOR THE EVENING AND OVERNIGHT TIME FRAME. THE
EXCEPTION WILL BE PORTIONS OF THE CHARLESTON TRI COUNTY
REGION...WHERE STRONG FORCING AS THE UPPER TROUGH PASSES OVER THE
AREA CAN TAP INTO LINGERING MOISTURE THAT SUPPORTS ISOLATED
SHOWERS TONIGHT. ALTHOUGH TEMPERATURES WILL QUICKLY FALL BEHIND
THE FRONT THROUGH THE EVENING/NIGHTTIME HOURS...LOWS WILL REMAIN
ABOVE FREEZING AND RANGE FROM AROUND 39 DEGREES FAR INLAND TO THE
LOW 40S ELSEWHERE. THUS...ANY LIGHT PRECIPITATION ACROSS NORTHERN
AREAS OVERNIGHT WILL BE IN THE FORM OF LIQUID RAIN. HOWEVER...STEEP
MID LEVEL LAPSE RATES AND VERY COLD AIR ALOFT COULD SUPPORT
ISOLATED SOFT HAIL OR GRAUPEL AS THE SHORT WAVE SWINGS THROUGH
THE AREA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
THE MAIN LINE OF CONVECTION HAS MOVED OFF THE COASTLINE BY 4 PM
EDT...WHILE SCATTERED SHOWERS HAVE DEVELOPED IN ITS WAKE ACROSS
PORTIONS OF THE CHARLESTON TRI COUNTY AREA. KCHS COULD STILL
EXPERIENCE -RA FOR ANOTHER HOUR OR TWO AS THIS SECONDARY SWATH OF
PRECIPITATION MOVES THROUGH THE AREA. DRY CONDITIONS AT BOTH TAF
SITES WILL THEN PREVAIL FOR THE REMAINDER OF THE TAF PERIOD...AS
DRIER AIR FILTERS INTO THE REGION BEHIND THE DEPARTING STRONG COLD
FRONT. VFR CONDITIONS WILL RETURN TO KCHS AND KSAV AROUND 01Z
THIS EVENING.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON COUNTY
WATERS AND THE OFFSHORE GEORGIA ZONES ARE QUITE MARGINAL BY LATE
AFTERNOON. PREFER TO KEEP THE ADVISORIES GOING AT THIS POINT
CONSIDERING THE PASSAGE OF A COLD FRONT IN THE NEXT FEW HOURS...AS
WELL AS POTENTIAL SURGING WITHIN A TIGHTENED GRADIENT AND ENHANCED
MIXING OVERNIGHT. AN ADDITIONAL ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WILL GO INTO EFFECT AT 11 PM EDT...AS THE SOUTHEAST GEORGIA
MARINE ZONES APPEAR TO FALL WITHIN THE TIGHTEST GRADIENT BETWEEN
THE EXITING FRONTAL TROUGH AND BUILDING INLAND SURFACE HIGH
PRESSURE. CRITERIA WILL MAINLY BE REACHED VIA FREQUENT GUSTS TO 25
KT.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$

SYNOPSIS...
NEAR TERM...WMS
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...WMS/ECT
MARINE...WMS/ECT





000
FXUS62 KCHS 272030
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
430 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL PASS OFF THE COAST EARLY THIS
EVENING...WITH UNSEASONABLY COLD HIGH PRESSURE PREVAILING THROUGH
THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM FRONT.
WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE MAIN LINE OF CONVECTION IS QUICKLY MOVING OFF THE COASTLINE
BY LATE AFTERNOON...WHILE ISOLATED TO SCATTERED SHOWERS HAVE
DEVELOPED IN ITS WAKE ACROSS THE NORTHERN SOUTH CAROLINA COUNTIES.
THE LOCATION OF THE COLD FRONT IS VERY DISTINCT WHEN EXAMINING
WIND REPORTS ACROSS THE REGION...WITH WIND DIRECTIONS HAVING
QUICKLY VEERED TO THE NORTH BEHIND THE DESCENDING FRONT. THE COLD
FRONT WILL STEADILY SHIFT THROUGH THE FORECAST AREA...ASSISTED IN
ITS PROGRESSION BY STRONG SHORTWAVE ENERGY DOWNSTREAM OF AN
AMPLIFYING UPPER TROUGH AXIS SWINGING EAST TOWARD THE AREA.

DRIER AIR WILL BE QUICKLY FILTERING INTO THE REGION DURING THE
NEXT SEVERAL HOURS...AND EXPECT THE MAJORITY OF THE FORECAST AREA
TO BE FREE OF RAIN FOR THE EVENING AND OVERNIGHT TIME FRAME. THE
EXCEPTION WILL BE PORTIONS OF THE CHARLESTON TRI COUNTY
REGION...WHERE STRONG FORCING AS THE UPPER TROUGH PASSES OVER THE
AREA CAN TAP INTO LINGERING MOISTURE THAT SUPPORTS ISOLATED
SHOWERS TONIGHT. ALTHOUGH TEMPERATURES WILL QUICKLY FALL BEHIND
THE FRONT THROUGH THE EVENING/NIGHTTIME HOURS...LOWS WILL REMAIN
ABOVE FREEZING AND RANGE FROM AROUND 39 DEGREES FAR INLAND TO THE
LOW 40S ELSEWHERE. THUS...ANY LIGHT PRECIPITATION ACROSS NORTHERN
AREAS OVERNIGHT WILL BE IN THE FORM OF LIQUID RAIN. HOWEVER...STEEP
MID LEVEL LAPSE RATES AND VERY COLD AIR ALOFT COULD SUPPORT
ISOLATED SOFT HAIL OR GRAUPEL AS THE SHORT WAVE SWINGS THROUGH
THE AREA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
THE MAIN LINE OF CONVECTION HAS MOVED OFF THE COASTLINE BY 4 PM
EDT...WHILE SCATTERED SHOWERS HAVE DEVELOPED IN ITS WAKE ACROSS
PORTIONS OF THE CHARLESTON TRI COUNTY AREA. KCHS COULD STILL
EXPERIENCE -RA FOR ANOTHER HOUR OR TWO AS THIS SECONDARY SWATH OF
PRECIPITATION MOVES THROUGH THE AREA. DRY CONDITIONS AT BOTH TAF
SITES WILL THEN PREVAIL FOR THE REMAINDER OF THE TAF PERIOD...AS
DRIER AIR FILTERS INTO THE REGION BEHIND THE DEPARTING STRONG COLD
FRONT. VFR CONDITIONS WILL RETURN TO KCHS AND KSAV AROUND 01Z
THIS EVENING.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON COUNTY
WATERS AND THE OFFSHORE GEORGIA ZONES ARE QUITE MARGINAL BY LATE
AFTERNOON. PREFER TO KEEP THE ADVISORIES GOING AT THIS POINT
CONSIDERING THE PASSAGE OF A COLD FRONT IN THE NEXT FEW HOURS...AS
WELL AS POTENTIAL SURGING WITHIN A TIGHTENED GRADIENT AND ENHANCED
MIXING OVERNIGHT. AN ADDITIONAL ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WILL GO INTO EFFECT AT 11 PM EDT...AS THE SOUTHEAST GEORGIA
MARINE ZONES APPEAR TO FALL WITHIN THE TIGHTEST GRADIENT BETWEEN
THE EXITING FRONTAL TROUGH AND BUILDING INLAND SURFACE HIGH
PRESSURE. CRITERIA WILL MAINLY BE REACHED VIA FREQUENT GUSTS TO 25
KT.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$

SYNOPSIS...
NEAR TERM...WMS
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...WMS/ECT
MARINE...WMS/ECT




000
FXUS62 KCHS 272030
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
430 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL PASS OFF THE COAST EARLY THIS
EVENING...WITH UNSEASONABLY COLD HIGH PRESSURE PREVAILING THROUGH
THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM FRONT.
WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE MAIN LINE OF CONVECTION IS QUICKLY MOVING OFF THE COASTLINE
BY LATE AFTERNOON...WHILE ISOLATED TO SCATTERED SHOWERS HAVE
DEVELOPED IN ITS WAKE ACROSS THE NORTHERN SOUTH CAROLINA COUNTIES.
THE LOCATION OF THE COLD FRONT IS VERY DISTINCT WHEN EXAMINING
WIND REPORTS ACROSS THE REGION...WITH WIND DIRECTIONS HAVING
QUICKLY VEERED TO THE NORTH BEHIND THE DESCENDING FRONT. THE COLD
FRONT WILL STEADILY SHIFT THROUGH THE FORECAST AREA...ASSISTED IN
ITS PROGRESSION BY STRONG SHORTWAVE ENERGY DOWNSTREAM OF AN
AMPLIFYING UPPER TROUGH AXIS SWINGING EAST TOWARD THE AREA.

DRIER AIR WILL BE QUICKLY FILTERING INTO THE REGION DURING THE
NEXT SEVERAL HOURS...AND EXPECT THE MAJORITY OF THE FORECAST AREA
TO BE FREE OF RAIN FOR THE EVENING AND OVERNIGHT TIME FRAME. THE
EXCEPTION WILL BE PORTIONS OF THE CHARLESTON TRI COUNTY
REGION...WHERE STRONG FORCING AS THE UPPER TROUGH PASSES OVER THE
AREA CAN TAP INTO LINGERING MOISTURE THAT SUPPORTS ISOLATED
SHOWERS TONIGHT. ALTHOUGH TEMPERATURES WILL QUICKLY FALL BEHIND
THE FRONT THROUGH THE EVENING/NIGHTTIME HOURS...LOWS WILL REMAIN
ABOVE FREEZING AND RANGE FROM AROUND 39 DEGREES FAR INLAND TO THE
LOW 40S ELSEWHERE. THUS...ANY LIGHT PRECIPITATION ACROSS NORTHERN
AREAS OVERNIGHT WILL BE IN THE FORM OF LIQUID RAIN. HOWEVER...STEEP
MID LEVEL LAPSE RATES AND VERY COLD AIR ALOFT COULD SUPPORT
ISOLATED SOFT HAIL OR GRAUPEL AS THE SHORT WAVE SWINGS THROUGH
THE AREA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
THE MAIN LINE OF CONVECTION HAS MOVED OFF THE COASTLINE BY 4 PM
EDT...WHILE SCATTERED SHOWERS HAVE DEVELOPED IN ITS WAKE ACROSS
PORTIONS OF THE CHARLESTON TRI COUNTY AREA. KCHS COULD STILL
EXPERIENCE -RA FOR ANOTHER HOUR OR TWO AS THIS SECONDARY SWATH OF
PRECIPITATION MOVES THROUGH THE AREA. DRY CONDITIONS AT BOTH TAF
SITES WILL THEN PREVAIL FOR THE REMAINDER OF THE TAF PERIOD...AS
DRIER AIR FILTERS INTO THE REGION BEHIND THE DEPARTING STRONG COLD
FRONT. VFR CONDITIONS WILL RETURN TO KCHS AND KSAV AROUND 01Z
THIS EVENING.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON COUNTY
WATERS AND THE OFFSHORE GEORGIA ZONES ARE QUITE MARGINAL BY LATE
AFTERNOON. PREFER TO KEEP THE ADVISORIES GOING AT THIS POINT
CONSIDERING THE PASSAGE OF A COLD FRONT IN THE NEXT FEW HOURS...AS
WELL AS POTENTIAL SURGING WITHIN A TIGHTENED GRADIENT AND ENHANCED
MIXING OVERNIGHT. AN ADDITIONAL ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WILL GO INTO EFFECT AT 11 PM EDT...AS THE SOUTHEAST GEORGIA
MARINE ZONES APPEAR TO FALL WITHIN THE TIGHTEST GRADIENT BETWEEN
THE EXITING FRONTAL TROUGH AND BUILDING INLAND SURFACE HIGH
PRESSURE. CRITERIA WILL MAINLY BE REACHED VIA FREQUENT GUSTS TO 25
KT.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$

SYNOPSIS...
NEAR TERM...WMS
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...WMS/ECT
MARINE...WMS/ECT




000
FXUS62 KCHS 272030
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
430 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL PASS OFF THE COAST EARLY THIS
EVENING...WITH UNSEASONABLY COLD HIGH PRESSURE PREVAILING THROUGH
THE WEEKEND. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM FRONT.
WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE MAIN LINE OF CONVECTION IS QUICKLY MOVING OFF THE COASTLINE
BY LATE AFTERNOON...WHILE ISOLATED TO SCATTERED SHOWERS HAVE
DEVELOPED IN ITS WAKE ACROSS THE NORTHERN SOUTH CAROLINA COUNTIES.
THE LOCATION OF THE COLD FRONT IS VERY DISTINCT WHEN EXAMINING
WIND REPORTS ACROSS THE REGION...WITH WIND DIRECTIONS HAVING
QUICKLY VEERED TO THE NORTH BEHIND THE DESCENDING FRONT. THE COLD
FRONT WILL STEADILY SHIFT THROUGH THE FORECAST AREA...ASSISTED IN
ITS PROGRESSION BY STRONG SHORTWAVE ENERGY DOWNSTREAM OF AN
AMPLIFYING UPPER TROUGH AXIS SWINGING EAST TOWARD THE AREA.

DRIER AIR WILL BE QUICKLY FILTERING INTO THE REGION DURING THE
NEXT SEVERAL HOURS...AND EXPECT THE MAJORITY OF THE FORECAST AREA
TO BE FREE OF RAIN FOR THE EVENING AND OVERNIGHT TIME FRAME. THE
EXCEPTION WILL BE PORTIONS OF THE CHARLESTON TRI COUNTY
REGION...WHERE STRONG FORCING AS THE UPPER TROUGH PASSES OVER THE
AREA CAN TAP INTO LINGERING MOISTURE THAT SUPPORTS ISOLATED
SHOWERS TONIGHT. ALTHOUGH TEMPERATURES WILL QUICKLY FALL BEHIND
THE FRONT THROUGH THE EVENING/NIGHTTIME HOURS...LOWS WILL REMAIN
ABOVE FREEZING AND RANGE FROM AROUND 39 DEGREES FAR INLAND TO THE
LOW 40S ELSEWHERE. THUS...ANY LIGHT PRECIPITATION ACROSS NORTHERN
AREAS OVERNIGHT WILL BE IN THE FORM OF LIQUID RAIN. HOWEVER...STEEP
MID LEVEL LAPSE RATES AND VERY COLD AIR ALOFT COULD SUPPORT
ISOLATED SOFT HAIL OR GRAUPEL AS THE SHORT WAVE SWINGS THROUGH
THE AREA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...THE FORECAST AREA WILL BE POSITIONED BETWEEN A DEPARTING
COLD FRONT AND SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST.
ALOFT...AN ANOMALOUSLY DEEP UPPER TROUGH AND ASSOCIATED VORT MAX
WILL BE SWINGING EAST ACROSS THE FORECAST AREA. 850 MB TEMPS AROUND
2 STANDARD DEVIATIONS BELOW NORMAL WILL SUPPORT HIGHS ONLY IN THE IN
THE UPPER 50S TO AROUND 60...AROUND 10-12 DEGREES BELOW CLIMATOLOGY.
SATURDAY NIGHT...CONTINUED COLD ADVECTION WILL COMBINE WITH MOSTLY
CLEAR SKIES AND PRODUCE UNSEASONABLY COLD TEMPERATURES. LOW
TEMPERATURES WILL RANGE FROM AROUND FREEZING INLAND TO MID/UPPER 30S
AT THE COAST. HAVE RAISED A FREEZE WATCH FOR OUR INTERIOR COUNTIES
TO ADDRESS THIS POTENTIAL. AS TRENDS BECOME CLEARER...A FROST
ADVISORY MAY BE NEEDED FOR COUNTIES CLOSER TO THE COAST.

SUNDAY...THE SURFACE HIGH WILL CONTINUE TO BUILD IN OVER THE AREA
AND WILL BE POSITIONED OVERHEAD BY MIDDAY. STRONG SUBSIDENCE WILL
PROVIDE A DRY AND SUNNY DAY. DESPITE FULL INSOLATION...THE AIR MASS
WILL NOT MODERATE MUCH. HIGH TEMPERATURES WILL YET AGAIN BE IN THE
UPPER 50S TO LOW 60S. SUNDAY NIGHT...MOSTLY CLEAR SKIES AND LIGHT
WINDS WILL ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS. LOW
TEMPERATURES WILL MAINLY BE IN THE LOW TO MID 40S.

MONDAY...SURFACE HIGH PRESSURE WILL SHIFT INTO THE ATLANTIC IN
RESPONSE TO A COLD FRONT APPROACHING FROM THE NORTHWEST. MOISTURE
AND FORCING IS NOT OVERLY IMPRESSIVE...HOWEVER LIFT FROM A PASSING
VORT MAX MAY KICK OFF SOME SHOWERS. CERTAINLY COULD NOT RULE OUT
THUNDER GIVEN DECENT MID LEVEL LAPSE RATES...HOWEVER INSTABILITY
LOOKS RATHER MEAGER SO HAVE OPTED TO LEAVE MENTION OUT OF FORECAST.
COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL HELP TEMPERATURES
REACH CLOSER TO NORMAL. HIGHS WILL RANGE FROM THE UPPER 60S ACROSS
OUR NORTHERN ZONES...TO LOW 70S IN THE SOUTH.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
THE MAIN LINE OF CONVECTION HAS MOVED OFF THE COASTLINE BY 4 PM
EDT...WHILE SCATTERED SHOWERS HAVE DEVELOPED IN ITS WAKE ACROSS
PORTIONS OF THE CHARLESTON TRI COUNTY AREA. KCHS COULD STILL
EXPERIENCE -RA FOR ANOTHER HOUR OR TWO AS THIS SECONDARY SWATH OF
PRECIPITATION MOVES THROUGH THE AREA. DRY CONDITIONS AT BOTH TAF
SITES WILL THEN PREVAIL FOR THE REMAINDER OF THE TAF PERIOD...AS
DRIER AIR FILTERS INTO THE REGION BEHIND THE DEPARTING STRONG COLD
FRONT. VFR CONDITIONS WILL RETURN TO KCHS AND KSAV AROUND 01Z
THIS EVENING.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TONIGHT...ONGOING SMALL CRAFT ADVISORIES FOR THE CHARLESTON COUNTY
WATERS AND THE OFFSHORE GEORGIA ZONES ARE QUITE MARGINAL BY LATE
AFTERNOON. PREFER TO KEEP THE ADVISORIES GOING AT THIS POINT
CONSIDERING THE PASSAGE OF A COLD FRONT IN THE NEXT FEW HOURS...AS
WELL AS POTENTIAL SURGING WITHIN A TIGHTENED GRADIENT AND ENHANCED
MIXING OVERNIGHT. AN ADDITIONAL ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WILL GO INTO EFFECT AT 11 PM EDT...AS THE SOUTHEAST GEORGIA
MARINE ZONES APPEAR TO FALL WITHIN THE TIGHTEST GRADIENT BETWEEN
THE EXITING FRONTAL TROUGH AND BUILDING INLAND SURFACE HIGH
PRESSURE. CRITERIA WILL MAINLY BE REACHED VIA FREQUENT GUSTS TO 25
KT.

SATURDAY THROUGH TUESDAY...WINDS/SEAS WILL BE ON A DIMINISHING TREND
SATURDAY AS THE DEPARTING COLD FRONT MOVES FURTHER OFFSHORE. THE
REMAINING SMALL CRAFT ADVISORY FOR THE OUTER GA WATERS WILL COME
DOWN BY LATE MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA
FROM THE NORTHWEST THROUGH THE WEEKEND. CONTINUED COLD ADVECTION AND
A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR A WIND SURGE EARLY
SUNDAY MORNING. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR A SHORT
PERIOD FOR OUR COASTAL SOUTH CAROLINA ZONES. THE SURFACE HIGH WILL
SHIFT OVERHEAD AND THEN SOUTHEAST OF THE WATERS LATE SUNDAY INTO
MONDAY IN RESPONSE TO AN APPROACHING COLD FRONT. THE FRONT WILL
CROSS THE WATERS LATE MONDAY INTO TUESDAY WITH ANOTHER SURGE IN
WINDS AND SEAS POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR GAZ087-088.
SC...FREEZE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING
     FOR SCZ040-042>045.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.

&&

$$

SYNOPSIS...
NEAR TERM...WMS
SHORT TERM...ECT
LONG TERM...SPR
AVIATION...WMS/ECT
MARINE...WMS/ECT





000
FXUS62 KCHS 271820
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
220 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL PASS THROUGH THE AREA THIS AFTERNOON.
UNSEASONABLY COLD HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST
AND AN INLAND FREEZE COULD OCCUR LATE SATURDAY NIGHT INTO EARLY
SUNDAY. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM
FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...A LINE OF CONVECTION AHEAD OF A STRONG COLD FRONT IS
CURRENTLY BISECTING THE FORECAST AREA AND STEADILY PROGRESSING
EAST. WEAK INSTABILITY HAS SUPPORTED ISOLATED THUNDER WITHIN THIS
LINE...HOWEVER THE MAJORITY OF THE ACTIVITY WILL BE LIGHT TO
MODERATE SHOWERS. RAIN COVERAGE WILL STEADILY END FROM SOUTHWEST
TO NORTHEAST AS THE FRONT SHIFTS TOWARD THE COAST DURING THE NEXT
SEVERAL HOURS AND CONVECTION LIFTS EAST/NORTHEAST ACCORDINGLY.

ALTHOUGH BREAKS IN THE THICK CLOUD COVER ARE POSSIBLE THROUGHOUT
THE DAY...WILL CONTINUE TO ADVERTISE MOSTLY CLOUDY CONDITIONS.
WARM ADVECTION IN ADVANCE OF THE FRONT...AS WELL AS PRE-FRONTAL
COMPRESSION EFFECTS...HAS ALLOWED TEMPERATURES TO RISE INTO THE
UPPER 60S TO LOW 70S. DEEP MIXING HAS DEVELOPED ACROSS PORTIONS OF
THE AREA THIS AFTERNOON AND SUPPORTED FREQUENT GUSTS.
WEST/NORTHWEST WINDS WILL PEAK IN THE 20 TO 25 MPH RANGE.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE SURFACE. A POTENT SHORT
WAVE EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE FORECAST AREA AROUND 05-10Z. THIS WILL SUPPORT 20-30
POPS...MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE
BEST MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND
THIS FEATURE...IT WILL BE SUFFICIENTLY DELAYED TO PREVENT ANYTHING
MORE THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH THE AREA. 850 MB TEMPS FALL TO AN
ANOMALOUSLY COLD -1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS
TO PLUNGE DOWN INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK
SATURDAY. THIS WILL BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
CEILINGS AT BOTH TERMINALS WILL LIKELY WAVER BETWEEN MARGINAL
MVFR AND VFR THROUGH THE AFTERNOON AHEAD OF A STRONG COLD FRONT
PROGRESSING THROUGH THE FORECAST AREA. A BAND OF SHOWERS AND
ISOLATED THUNDERSTORMS ARE STEADILY SHIFTING TOWARD BOTH
TERMINALS BY 2 PM EDT. HAVE INCLUDED A TEMPO GROUP TO ADDRESS THE
POTENTIAL FOR SHOWERS TO AFFECT KCHS AND KSAV THROUGH ABOUT
20Z...AND WILL MONITOR TRENDS IN CASE THUNDER NEEDS TO BE ADDED TO
THE TAF. CONDITIONS WILL IMPROVE BACK TO PREVAILING VFR THIS
EVENING AND TONIGHT BEHIND THE COLD FRONT...AS DRIER AIR STEADILY
ADVECTS INTO THE REGION.

SOUTHWEST/WEST WINDS WILL BE GUSTY THROUGH THE AFTERNOON AND
PERHAPS INTO THE EVENING HOURS...BEFORE DIMINISHING OVERNIGHT.
COMPLETE DECOUPLING IS NOT EXPECTED DUE TO A TIGHTENED PRESSURE
GRADIENT BEHIND THE DEPARTING COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL REACH THE COASTAL WATERS IN THE
NEXT SEVERAL HOURS...PASSING TO THE EAST/SOUTHEAST BY LATE
AFTERNOON. DESPITE SOME MARINE LAYERING EFFECTS WITHIN THE WARM
ADVECTION...A FAIRLY DECENT PRESSURE GRADIENT WILL ASSIST IN
INCREASING SOUTHWEST WINDS INTO THE 15 TO 20 KT RANGE. THERE WILL
EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE OUTER GEORGIA WATERS
AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON COUNTY ATLANTIC
WATERS. THIS WILL BE SUFFICIENT TO ALLOW SEAS TO BUILD TO 6 FT ON
THESE AFOREMENTIONED MARINE ZONES...SUPPORTING MARGINAL SMALL
CRAFT ADVISORIES. THE OTHER ZONES WILL STAY JUST BELOW ANY
ADVISORY CONDITIONS THROUGH THE DAY. MEANWHILE...PATCHY SEA FOG
WILL PERSIST INTO THE AFTERNOON...UNTIL WINDS VEER TO WEST AND
SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED THAT A FEW
THUNDERSTORMS COULD MOVE THROUGH THIS AFTERNOON.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
HAVE RAISED ANOTHER SMALL CRAFT ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WHERE FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE
COLD ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GEORGIA WATERS FOR SEAS OF 6 FT AND GUSTS
OF 25 OR 30 KT. CONDITIONS WILL BE CLOSE TO ADVISORY THRESHOLDS
ON THE SOUTH CAROLINA ATLANTIC WATERS...AND MAY STILL NEED TO
RAISE ADDITIONAL ADVISORIES AT A LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...





000
FXUS62 KCHS 271820
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
220 PM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL PASS THROUGH THE AREA THIS AFTERNOON.
UNSEASONABLY COLD HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST
AND AN INLAND FREEZE COULD OCCUR LATE SATURDAY NIGHT INTO EARLY
SUNDAY. ANOTHER COLD FRONT WILL MOVE THROUGH LATE MONDAY INTO
EARLY TUESDAY...EVENTUALLY LIFTING BACK NORTH AS A WARM
FRONT. WARMER HIGH PRESSURE WILL THEN BUILD OVER THE REGION
THROUGH THE MIDDLE OF NEXT WEEK. YET ANOTHER COLD FRONT COULD
APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...A LINE OF CONVECTION AHEAD OF A STRONG COLD FRONT IS
CURRENTLY BISECTING THE FORECAST AREA AND STEADILY PROGRESSING
EAST. WEAK INSTABILITY HAS SUPPORTED ISOLATED THUNDER WITHIN THIS
LINE...HOWEVER THE MAJORITY OF THE ACTIVITY WILL BE LIGHT TO
MODERATE SHOWERS. RAIN COVERAGE WILL STEADILY END FROM SOUTHWEST
TO NORTHEAST AS THE FRONT SHIFTS TOWARD THE COAST DURING THE NEXT
SEVERAL HOURS AND CONVECTION LIFTS EAST/NORTHEAST ACCORDINGLY.

ALTHOUGH BREAKS IN THE THICK CLOUD COVER ARE POSSIBLE THROUGHOUT
THE DAY...WILL CONTINUE TO ADVERTISE MOSTLY CLOUDY CONDITIONS.
WARM ADVECTION IN ADVANCE OF THE FRONT...AS WELL AS PRE-FRONTAL
COMPRESSION EFFECTS...HAS ALLOWED TEMPERATURES TO RISE INTO THE
UPPER 60S TO LOW 70S. DEEP MIXING HAS DEVELOPED ACROSS PORTIONS OF
THE AREA THIS AFTERNOON AND SUPPORTED FREQUENT GUSTS.
WEST/NORTHWEST WINDS WILL PEAK IN THE 20 TO 25 MPH RANGE.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE SURFACE. A POTENT SHORT
WAVE EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE FORECAST AREA AROUND 05-10Z. THIS WILL SUPPORT 20-30
POPS...MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE
BEST MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND
THIS FEATURE...IT WILL BE SUFFICIENTLY DELAYED TO PREVENT ANYTHING
MORE THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH THE AREA. 850 MB TEMPS FALL TO AN
ANOMALOUSLY COLD -1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS
TO PLUNGE DOWN INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK
SATURDAY. THIS WILL BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
CEILINGS AT BOTH TERMINALS WILL LIKELY WAVER BETWEEN MARGINAL
MVFR AND VFR THROUGH THE AFTERNOON AHEAD OF A STRONG COLD FRONT
PROGRESSING THROUGH THE FORECAST AREA. A BAND OF SHOWERS AND
ISOLATED THUNDERSTORMS ARE STEADILY SHIFTING TOWARD BOTH
TERMINALS BY 2 PM EDT. HAVE INCLUDED A TEMPO GROUP TO ADDRESS THE
POTENTIAL FOR SHOWERS TO AFFECT KCHS AND KSAV THROUGH ABOUT
20Z...AND WILL MONITOR TRENDS IN CASE THUNDER NEEDS TO BE ADDED TO
THE TAF. CONDITIONS WILL IMPROVE BACK TO PREVAILING VFR THIS
EVENING AND TONIGHT BEHIND THE COLD FRONT...AS DRIER AIR STEADILY
ADVECTS INTO THE REGION.

SOUTHWEST/WEST WINDS WILL BE GUSTY THROUGH THE AFTERNOON AND
PERHAPS INTO THE EVENING HOURS...BEFORE DIMINISHING OVERNIGHT.
COMPLETE DECOUPLING IS NOT EXPECTED DUE TO A TIGHTENED PRESSURE
GRADIENT BEHIND THE DEPARTING COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL REACH THE COASTAL WATERS IN THE
NEXT SEVERAL HOURS...PASSING TO THE EAST/SOUTHEAST BY LATE
AFTERNOON. DESPITE SOME MARINE LAYERING EFFECTS WITHIN THE WARM
ADVECTION...A FAIRLY DECENT PRESSURE GRADIENT WILL ASSIST IN
INCREASING SOUTHWEST WINDS INTO THE 15 TO 20 KT RANGE. THERE WILL
EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE OUTER GEORGIA WATERS
AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON COUNTY ATLANTIC
WATERS. THIS WILL BE SUFFICIENT TO ALLOW SEAS TO BUILD TO 6 FT ON
THESE AFOREMENTIONED MARINE ZONES...SUPPORTING MARGINAL SMALL
CRAFT ADVISORIES. THE OTHER ZONES WILL STAY JUST BELOW ANY
ADVISORY CONDITIONS THROUGH THE DAY. MEANWHILE...PATCHY SEA FOG
WILL PERSIST INTO THE AFTERNOON...UNTIL WINDS VEER TO WEST AND
SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED THAT A FEW
THUNDERSTORMS COULD MOVE THROUGH THIS AFTERNOON.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
HAVE RAISED ANOTHER SMALL CRAFT ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WHERE FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE
COLD ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GEORGIA WATERS FOR SEAS OF 6 FT AND GUSTS
OF 25 OR 30 KT. CONDITIONS WILL BE CLOSE TO ADVISORY THRESHOLDS
ON THE SOUTH CAROLINA ATLANTIC WATERS...AND MAY STILL NEED TO
RAISE ADDITIONAL ADVISORIES AT A LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...




000
FXUS62 KCHS 271505
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1105 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
EVENTUALLY LIFT BACK NORTH AS A WARM FRONT...WITH WARMER HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF NEXT
WEEK. ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...LATEST MESOANALYSIS PLACES THE STRONG COLD FRONT JUST TO
THE WEST OF THE FORECAST AREA BY LATE MORNING...WHILE THE AXIS OF
AN AMPLIFYING UPPER TROUGH CONTINUES SHIFT TOWARD THE EAST COAST.
LATEST RADAR TRENDS HAS REQUIRED SUBSTANTIAL CHANGES TO THE
RAINFALL FORECAST FOR AT LEAST THE NEXT FEW HOURS. PRECIPITATION
CURRENTLY ALONG AND AHEAD OF THE APPROACHING FRONT HAS BEEN QUITE
LIGHT AND HAS STRUGGLED TO PROGRESS EASTWARD THROUGH THE MORNING.
EXAMINATION OF HIGH RESOLUTIONS MODEL SOLUTIONS SUGGESTS THAT MUCH
OF THE FORECAST AREA COULD REMAIN DRY FOR THE NEXT HOUR OR
TWO...BEFORE A WAVE DEVELOPS ALONG THE FRONT AND SUPPORTS A SURGE
IN RAIN COVERAGE BETWEEN ABOUT 2 PM AND 5 PM THIS AFTERNOON. RAP
AND HRRR SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT INDICATING BEST
RAIN COVERAGE ACROSS THE CHARLESTON TRI COUNTY REGION AND BOTH
SOUTH CAROLINA AND GEORGIA COASTAL COUNTIES DURING THE TIME. HAVE
THUS ADVERTISED HIGHEST RAIN CHANCES IN THE 65 TO 70 PERCENT RANGE
ACROSS THESE AREAS. RAIN COVERAGE WILL STEADILY END FROM SOUTHWEST
TO NORTHEAST ONCE THE FRONT SHIFTS OFF THE COAST BY LATE
AFTERNOON. NUMERICAL MODELS ARE STILL SHOWING WEAK INSTABILITY
DEVELOPING LATER TODAY...AND HAVE THEREFORE MAINTAINED A NARROW
WINDOW OF OPPORTUNITY FOR ISOLATED THUNDER.

ALTHOUGH BREAKS IN THE THICK CLOUD COVER ARE POSSIBLE THROUGHOUT
THE DAY...WILL CONTINUE TO ADVERTISE MOSTLY CLOUDY CONDITIONS.
WARM ADVECTION IN ADVANCE OF THE FRONT...AS WELL AS PRE-FRONTAL
COMPRESSION EFFECTS...WILL SUPPORT HIGH TEMPERATURES IN THE UPPER
60S NORTH AND WEST TO LOW/MID 70S SOUTH AND EAST. IF CLOUD COVER
SCATTERS MORE THAN ANTICIPATED...TEMPERATURES COULD JUMP SEVERAL
MORE DEGREES. DEEPER MIXING WILL DEVELOP ACROSS SOUTHEAST GEORGIA
DURING THE MID AND LATE AFTERNOON AS THE DRIER AIR WORKS INTO THE
REGION AND THE GRADIENT TIGHTENS BEHIND THE FRONT. GUSTY
WEST/NORTHWEST WINDS COULD THUS INCREASE INTO THE 20 TO 25 MPH
RANGE. FURTHER NORTH IN SOUTH CAROLINA...THE CONDITIONS ARE NOT
QUITE AS FAVORABLE...YET STILL EXPECT WINDS TO PEAK AT 15 TO 20
MPH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE SURFACE. A POTENT SHORT
WAVE EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE FORECAST AREA AROUND 05-10Z. THIS WILL SUPPORT 20-30
POPS...MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE
BEST MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND
THIS FEATURE...IT WILL BE SUFFICIENTLY DELAYED TO PREVENT ANYTHING
MORE THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH THE AREA. 850 MB TEMPS FALL TO AN
ANOMALOUSLY COLD -1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS
TO PLUNGE DOWN INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK
SATURDAY. THIS WILL BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
ALTHOUGH CEILINGS COULD PERIODICALLY SCATTER THROUGH THE
DAY...EXPECT MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST
MAJORITY OF THE DAYTIME HOURS...WITH PLENTY OF LOW LEVEL MOISTURE
IN PLACE. A BAND OF SHOWERS AND MAYBE AN ISOLATED THUNDERSTORM
WILL MOVE THROUGH THE AREA IN ASSOCIATION WITH A STRONG COLD FRONT
FROM MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD
OF IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD
FRONT...AS DRIER AIR STEADILY WORKS ITS WAY INTO THE REGION.

WEST WINDS WILL BECOME GUSTY FOR THIS AFTERNOON...AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE COLD FRONT. WINDS WILL PEAK AROUND 20 KT AT KCHS AND AROUND 25
KT AT KSAV FOR SEVERAL HOURS LATE IN THE DAY BEHIND THE DEPARTING
COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL REACH THE COASTAL WATERS IN THE
NEXT SEVERAL HOURS...PASSING TO THE EAST/SOUTHEAST BY LATE
AFTERNOON. DESPITE SOME MARINE LAYERING EFFECTS WITHIN THE WARM
ADVECTION...A FAIRLY DECENT PRESSURE GRADIENT WILL ASSIST IN
INCREASING SOUTHWEST WINDS INTO THE 15 TO 20 KT RANGE. THERE WILL
EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE OUTER GEORGIA WATERS
AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON COUNTY ATLANTIC
WATERS. THIS WILL BE SUFFICIENT TO ALLOW SEAS TO BUILD TO 6 FT ON
THESE AFOREMENTIONED MARINE ZONES...SUPPORTING MARGINAL SMALL
CRAFT ADVISORIES. THE OTHER ZONES WILL STAY JUST BELOW ANY
ADVISORY CONDITIONS THROUGH THE DAY. MEANWHILE...PATCHY SEA FOG
WILL PERSIST INTO THE AFTERNOON...UNTIL WINDS VEER TO WEST AND
SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED THAT A FEW
THUNDERSTORMS COULD MOVE THROUGH THIS AFTERNOON.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
HAVE RAISED ANOTHER SMALL CRAFT ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WHERE FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE
COLD ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GEORGIA WATERS FOR SEAS OF 6 FT AND GUSTS
OF 25 OR 30 KT. CONDITIONS WILL BE CLOSE TO ADVISORY THRESHOLDS
ON THE SOUTH CAROLINA ATLANTIC WATERS...AND MAY STILL NEED TO
RAISE ADDITIONAL ADVISORIES AT A LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...





000
FXUS62 KCHS 271505
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1105 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
EVENTUALLY LIFT BACK NORTH AS A WARM FRONT...WITH WARMER HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF NEXT
WEEK. ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...LATEST MESOANALYSIS PLACES THE STRONG COLD FRONT JUST TO
THE WEST OF THE FORECAST AREA BY LATE MORNING...WHILE THE AXIS OF
AN AMPLIFYING UPPER TROUGH CONTINUES SHIFT TOWARD THE EAST COAST.
LATEST RADAR TRENDS HAS REQUIRED SUBSTANTIAL CHANGES TO THE
RAINFALL FORECAST FOR AT LEAST THE NEXT FEW HOURS. PRECIPITATION
CURRENTLY ALONG AND AHEAD OF THE APPROACHING FRONT HAS BEEN QUITE
LIGHT AND HAS STRUGGLED TO PROGRESS EASTWARD THROUGH THE MORNING.
EXAMINATION OF HIGH RESOLUTIONS MODEL SOLUTIONS SUGGESTS THAT MUCH
OF THE FORECAST AREA COULD REMAIN DRY FOR THE NEXT HOUR OR
TWO...BEFORE A WAVE DEVELOPS ALONG THE FRONT AND SUPPORTS A SURGE
IN RAIN COVERAGE BETWEEN ABOUT 2 PM AND 5 PM THIS AFTERNOON. RAP
AND HRRR SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT INDICATING BEST
RAIN COVERAGE ACROSS THE CHARLESTON TRI COUNTY REGION AND BOTH
SOUTH CAROLINA AND GEORGIA COASTAL COUNTIES DURING THE TIME. HAVE
THUS ADVERTISED HIGHEST RAIN CHANCES IN THE 65 TO 70 PERCENT RANGE
ACROSS THESE AREAS. RAIN COVERAGE WILL STEADILY END FROM SOUTHWEST
TO NORTHEAST ONCE THE FRONT SHIFTS OFF THE COAST BY LATE
AFTERNOON. NUMERICAL MODELS ARE STILL SHOWING WEAK INSTABILITY
DEVELOPING LATER TODAY...AND HAVE THEREFORE MAINTAINED A NARROW
WINDOW OF OPPORTUNITY FOR ISOLATED THUNDER.

ALTHOUGH BREAKS IN THE THICK CLOUD COVER ARE POSSIBLE THROUGHOUT
THE DAY...WILL CONTINUE TO ADVERTISE MOSTLY CLOUDY CONDITIONS.
WARM ADVECTION IN ADVANCE OF THE FRONT...AS WELL AS PRE-FRONTAL
COMPRESSION EFFECTS...WILL SUPPORT HIGH TEMPERATURES IN THE UPPER
60S NORTH AND WEST TO LOW/MID 70S SOUTH AND EAST. IF CLOUD COVER
SCATTERS MORE THAN ANTICIPATED...TEMPERATURES COULD JUMP SEVERAL
MORE DEGREES. DEEPER MIXING WILL DEVELOP ACROSS SOUTHEAST GEORGIA
DURING THE MID AND LATE AFTERNOON AS THE DRIER AIR WORKS INTO THE
REGION AND THE GRADIENT TIGHTENS BEHIND THE FRONT. GUSTY
WEST/NORTHWEST WINDS COULD THUS INCREASE INTO THE 20 TO 25 MPH
RANGE. FURTHER NORTH IN SOUTH CAROLINA...THE CONDITIONS ARE NOT
QUITE AS FAVORABLE...YET STILL EXPECT WINDS TO PEAK AT 15 TO 20
MPH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE SURFACE. A POTENT SHORT
WAVE EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE FORECAST AREA AROUND 05-10Z. THIS WILL SUPPORT 20-30
POPS...MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE
BEST MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND
THIS FEATURE...IT WILL BE SUFFICIENTLY DELAYED TO PREVENT ANYTHING
MORE THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH THE AREA. 850 MB TEMPS FALL TO AN
ANOMALOUSLY COLD -1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS
TO PLUNGE DOWN INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK
SATURDAY. THIS WILL BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
ALTHOUGH CEILINGS COULD PERIODICALLY SCATTER THROUGH THE
DAY...EXPECT MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST
MAJORITY OF THE DAYTIME HOURS...WITH PLENTY OF LOW LEVEL MOISTURE
IN PLACE. A BAND OF SHOWERS AND MAYBE AN ISOLATED THUNDERSTORM
WILL MOVE THROUGH THE AREA IN ASSOCIATION WITH A STRONG COLD FRONT
FROM MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD
OF IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD
FRONT...AS DRIER AIR STEADILY WORKS ITS WAY INTO THE REGION.

WEST WINDS WILL BECOME GUSTY FOR THIS AFTERNOON...AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE COLD FRONT. WINDS WILL PEAK AROUND 20 KT AT KCHS AND AROUND 25
KT AT KSAV FOR SEVERAL HOURS LATE IN THE DAY BEHIND THE DEPARTING
COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL REACH THE COASTAL WATERS IN THE
NEXT SEVERAL HOURS...PASSING TO THE EAST/SOUTHEAST BY LATE
AFTERNOON. DESPITE SOME MARINE LAYERING EFFECTS WITHIN THE WARM
ADVECTION...A FAIRLY DECENT PRESSURE GRADIENT WILL ASSIST IN
INCREASING SOUTHWEST WINDS INTO THE 15 TO 20 KT RANGE. THERE WILL
EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE OUTER GEORGIA WATERS
AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON COUNTY ATLANTIC
WATERS. THIS WILL BE SUFFICIENT TO ALLOW SEAS TO BUILD TO 6 FT ON
THESE AFOREMENTIONED MARINE ZONES...SUPPORTING MARGINAL SMALL
CRAFT ADVISORIES. THE OTHER ZONES WILL STAY JUST BELOW ANY
ADVISORY CONDITIONS THROUGH THE DAY. MEANWHILE...PATCHY SEA FOG
WILL PERSIST INTO THE AFTERNOON...UNTIL WINDS VEER TO WEST AND
SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED THAT A FEW
THUNDERSTORMS COULD MOVE THROUGH THIS AFTERNOON.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
HAVE RAISED ANOTHER SMALL CRAFT ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WHERE FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE
COLD ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GEORGIA WATERS FOR SEAS OF 6 FT AND GUSTS
OF 25 OR 30 KT. CONDITIONS WILL BE CLOSE TO ADVISORY THRESHOLDS
ON THE SOUTH CAROLINA ATLANTIC WATERS...AND MAY STILL NEED TO
RAISE ADDITIONAL ADVISORIES AT A LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...




000
FXUS62 KCHS 271505
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1105 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
EVENTUALLY LIFT BACK NORTH AS A WARM FRONT...WITH WARMER HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF NEXT
WEEK. ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...LATEST MESOANALYSIS PLACES THE STRONG COLD FRONT JUST TO
THE WEST OF THE FORECAST AREA BY LATE MORNING...WHILE THE AXIS OF
AN AMPLIFYING UPPER TROUGH CONTINUES SHIFT TOWARD THE EAST COAST.
LATEST RADAR TRENDS HAS REQUIRED SUBSTANTIAL CHANGES TO THE
RAINFALL FORECAST FOR AT LEAST THE NEXT FEW HOURS. PRECIPITATION
CURRENTLY ALONG AND AHEAD OF THE APPROACHING FRONT HAS BEEN QUITE
LIGHT AND HAS STRUGGLED TO PROGRESS EASTWARD THROUGH THE MORNING.
EXAMINATION OF HIGH RESOLUTIONS MODEL SOLUTIONS SUGGESTS THAT MUCH
OF THE FORECAST AREA COULD REMAIN DRY FOR THE NEXT HOUR OR
TWO...BEFORE A WAVE DEVELOPS ALONG THE FRONT AND SUPPORTS A SURGE
IN RAIN COVERAGE BETWEEN ABOUT 2 PM AND 5 PM THIS AFTERNOON. RAP
AND HRRR SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT INDICATING BEST
RAIN COVERAGE ACROSS THE CHARLESTON TRI COUNTY REGION AND BOTH
SOUTH CAROLINA AND GEORGIA COASTAL COUNTIES DURING THE TIME. HAVE
THUS ADVERTISED HIGHEST RAIN CHANCES IN THE 65 TO 70 PERCENT RANGE
ACROSS THESE AREAS. RAIN COVERAGE WILL STEADILY END FROM SOUTHWEST
TO NORTHEAST ONCE THE FRONT SHIFTS OFF THE COAST BY LATE
AFTERNOON. NUMERICAL MODELS ARE STILL SHOWING WEAK INSTABILITY
DEVELOPING LATER TODAY...AND HAVE THEREFORE MAINTAINED A NARROW
WINDOW OF OPPORTUNITY FOR ISOLATED THUNDER.

ALTHOUGH BREAKS IN THE THICK CLOUD COVER ARE POSSIBLE THROUGHOUT
THE DAY...WILL CONTINUE TO ADVERTISE MOSTLY CLOUDY CONDITIONS.
WARM ADVECTION IN ADVANCE OF THE FRONT...AS WELL AS PRE-FRONTAL
COMPRESSION EFFECTS...WILL SUPPORT HIGH TEMPERATURES IN THE UPPER
60S NORTH AND WEST TO LOW/MID 70S SOUTH AND EAST. IF CLOUD COVER
SCATTERS MORE THAN ANTICIPATED...TEMPERATURES COULD JUMP SEVERAL
MORE DEGREES. DEEPER MIXING WILL DEVELOP ACROSS SOUTHEAST GEORGIA
DURING THE MID AND LATE AFTERNOON AS THE DRIER AIR WORKS INTO THE
REGION AND THE GRADIENT TIGHTENS BEHIND THE FRONT. GUSTY
WEST/NORTHWEST WINDS COULD THUS INCREASE INTO THE 20 TO 25 MPH
RANGE. FURTHER NORTH IN SOUTH CAROLINA...THE CONDITIONS ARE NOT
QUITE AS FAVORABLE...YET STILL EXPECT WINDS TO PEAK AT 15 TO 20
MPH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE SURFACE. A POTENT SHORT
WAVE EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE FORECAST AREA AROUND 05-10Z. THIS WILL SUPPORT 20-30
POPS...MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE
BEST MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND
THIS FEATURE...IT WILL BE SUFFICIENTLY DELAYED TO PREVENT ANYTHING
MORE THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH THE AREA. 850 MB TEMPS FALL TO AN
ANOMALOUSLY COLD -1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS
TO PLUNGE DOWN INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK
SATURDAY. THIS WILL BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
ALTHOUGH CEILINGS COULD PERIODICALLY SCATTER THROUGH THE
DAY...EXPECT MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST
MAJORITY OF THE DAYTIME HOURS...WITH PLENTY OF LOW LEVEL MOISTURE
IN PLACE. A BAND OF SHOWERS AND MAYBE AN ISOLATED THUNDERSTORM
WILL MOVE THROUGH THE AREA IN ASSOCIATION WITH A STRONG COLD FRONT
FROM MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD
OF IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD
FRONT...AS DRIER AIR STEADILY WORKS ITS WAY INTO THE REGION.

WEST WINDS WILL BECOME GUSTY FOR THIS AFTERNOON...AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE COLD FRONT. WINDS WILL PEAK AROUND 20 KT AT KCHS AND AROUND 25
KT AT KSAV FOR SEVERAL HOURS LATE IN THE DAY BEHIND THE DEPARTING
COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL REACH THE COASTAL WATERS IN THE
NEXT SEVERAL HOURS...PASSING TO THE EAST/SOUTHEAST BY LATE
AFTERNOON. DESPITE SOME MARINE LAYERING EFFECTS WITHIN THE WARM
ADVECTION...A FAIRLY DECENT PRESSURE GRADIENT WILL ASSIST IN
INCREASING SOUTHWEST WINDS INTO THE 15 TO 20 KT RANGE. THERE WILL
EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE OUTER GEORGIA WATERS
AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON COUNTY ATLANTIC
WATERS. THIS WILL BE SUFFICIENT TO ALLOW SEAS TO BUILD TO 6 FT ON
THESE AFOREMENTIONED MARINE ZONES...SUPPORTING MARGINAL SMALL
CRAFT ADVISORIES. THE OTHER ZONES WILL STAY JUST BELOW ANY
ADVISORY CONDITIONS THROUGH THE DAY. MEANWHILE...PATCHY SEA FOG
WILL PERSIST INTO THE AFTERNOON...UNTIL WINDS VEER TO WEST AND
SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED THAT A FEW
THUNDERSTORMS COULD MOVE THROUGH THIS AFTERNOON.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
HAVE RAISED ANOTHER SMALL CRAFT ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WHERE FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE
COLD ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GEORGIA WATERS FOR SEAS OF 6 FT AND GUSTS
OF 25 OR 30 KT. CONDITIONS WILL BE CLOSE TO ADVISORY THRESHOLDS
ON THE SOUTH CAROLINA ATLANTIC WATERS...AND MAY STILL NEED TO
RAISE ADDITIONAL ADVISORIES AT A LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...





000
FXUS62 KCHS 271505
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1105 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
EVENTUALLY LIFT BACK NORTH AS A WARM FRONT...WITH WARMER HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF NEXT
WEEK. ANOTHER COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...LATEST MESOANALYSIS PLACES THE STRONG COLD FRONT JUST TO
THE WEST OF THE FORECAST AREA BY LATE MORNING...WHILE THE AXIS OF
AN AMPLIFYING UPPER TROUGH CONTINUES SHIFT TOWARD THE EAST COAST.
LATEST RADAR TRENDS HAS REQUIRED SUBSTANTIAL CHANGES TO THE
RAINFALL FORECAST FOR AT LEAST THE NEXT FEW HOURS. PRECIPITATION
CURRENTLY ALONG AND AHEAD OF THE APPROACHING FRONT HAS BEEN QUITE
LIGHT AND HAS STRUGGLED TO PROGRESS EASTWARD THROUGH THE MORNING.
EXAMINATION OF HIGH RESOLUTIONS MODEL SOLUTIONS SUGGESTS THAT MUCH
OF THE FORECAST AREA COULD REMAIN DRY FOR THE NEXT HOUR OR
TWO...BEFORE A WAVE DEVELOPS ALONG THE FRONT AND SUPPORTS A SURGE
IN RAIN COVERAGE BETWEEN ABOUT 2 PM AND 5 PM THIS AFTERNOON. RAP
AND HRRR SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT INDICATING BEST
RAIN COVERAGE ACROSS THE CHARLESTON TRI COUNTY REGION AND BOTH
SOUTH CAROLINA AND GEORGIA COASTAL COUNTIES DURING THE TIME. HAVE
THUS ADVERTISED HIGHEST RAIN CHANCES IN THE 65 TO 70 PERCENT RANGE
ACROSS THESE AREAS. RAIN COVERAGE WILL STEADILY END FROM SOUTHWEST
TO NORTHEAST ONCE THE FRONT SHIFTS OFF THE COAST BY LATE
AFTERNOON. NUMERICAL MODELS ARE STILL SHOWING WEAK INSTABILITY
DEVELOPING LATER TODAY...AND HAVE THEREFORE MAINTAINED A NARROW
WINDOW OF OPPORTUNITY FOR ISOLATED THUNDER.

ALTHOUGH BREAKS IN THE THICK CLOUD COVER ARE POSSIBLE THROUGHOUT
THE DAY...WILL CONTINUE TO ADVERTISE MOSTLY CLOUDY CONDITIONS.
WARM ADVECTION IN ADVANCE OF THE FRONT...AS WELL AS PRE-FRONTAL
COMPRESSION EFFECTS...WILL SUPPORT HIGH TEMPERATURES IN THE UPPER
60S NORTH AND WEST TO LOW/MID 70S SOUTH AND EAST. IF CLOUD COVER
SCATTERS MORE THAN ANTICIPATED...TEMPERATURES COULD JUMP SEVERAL
MORE DEGREES. DEEPER MIXING WILL DEVELOP ACROSS SOUTHEAST GEORGIA
DURING THE MID AND LATE AFTERNOON AS THE DRIER AIR WORKS INTO THE
REGION AND THE GRADIENT TIGHTENS BEHIND THE FRONT. GUSTY
WEST/NORTHWEST WINDS COULD THUS INCREASE INTO THE 20 TO 25 MPH
RANGE. FURTHER NORTH IN SOUTH CAROLINA...THE CONDITIONS ARE NOT
QUITE AS FAVORABLE...YET STILL EXPECT WINDS TO PEAK AT 15 TO 20
MPH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE SURFACE. A POTENT SHORT
WAVE EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE FORECAST AREA AROUND 05-10Z. THIS WILL SUPPORT 20-30
POPS...MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE
BEST MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND
THIS FEATURE...IT WILL BE SUFFICIENTLY DELAYED TO PREVENT ANYTHING
MORE THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH THE AREA. 850 MB TEMPS FALL TO AN
ANOMALOUSLY COLD -1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS
TO PLUNGE DOWN INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK
SATURDAY. THIS WILL BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
ALTHOUGH CEILINGS COULD PERIODICALLY SCATTER THROUGH THE
DAY...EXPECT MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST
MAJORITY OF THE DAYTIME HOURS...WITH PLENTY OF LOW LEVEL MOISTURE
IN PLACE. A BAND OF SHOWERS AND MAYBE AN ISOLATED THUNDERSTORM
WILL MOVE THROUGH THE AREA IN ASSOCIATION WITH A STRONG COLD FRONT
FROM MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD
OF IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD
FRONT...AS DRIER AIR STEADILY WORKS ITS WAY INTO THE REGION.

WEST WINDS WILL BECOME GUSTY FOR THIS AFTERNOON...AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE COLD FRONT. WINDS WILL PEAK AROUND 20 KT AT KCHS AND AROUND 25
KT AT KSAV FOR SEVERAL HOURS LATE IN THE DAY BEHIND THE DEPARTING
COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL REACH THE COASTAL WATERS IN THE
NEXT SEVERAL HOURS...PASSING TO THE EAST/SOUTHEAST BY LATE
AFTERNOON. DESPITE SOME MARINE LAYERING EFFECTS WITHIN THE WARM
ADVECTION...A FAIRLY DECENT PRESSURE GRADIENT WILL ASSIST IN
INCREASING SOUTHWEST WINDS INTO THE 15 TO 20 KT RANGE. THERE WILL
EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE OUTER GEORGIA WATERS
AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON COUNTY ATLANTIC
WATERS. THIS WILL BE SUFFICIENT TO ALLOW SEAS TO BUILD TO 6 FT ON
THESE AFOREMENTIONED MARINE ZONES...SUPPORTING MARGINAL SMALL
CRAFT ADVISORIES. THE OTHER ZONES WILL STAY JUST BELOW ANY
ADVISORY CONDITIONS THROUGH THE DAY. MEANWHILE...PATCHY SEA FOG
WILL PERSIST INTO THE AFTERNOON...UNTIL WINDS VEER TO WEST AND
SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED THAT A FEW
THUNDERSTORMS COULD MOVE THROUGH THIS AFTERNOON.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
HAVE RAISED ANOTHER SMALL CRAFT ADVISORY FOR THE NEARSHORE GEORGIA
WATERS WHERE FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE
COLD ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GEORGIA WATERS FOR SEAS OF 6 FT AND GUSTS
OF 25 OR 30 KT. CONDITIONS WILL BE CLOSE TO ADVISORY THRESHOLDS
ON THE SOUTH CAROLINA ATLANTIC WATERS...AND MAY STILL NEED TO
RAISE ADDITIONAL ADVISORIES AT A LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...WMS/
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...WMS/
MARINE...




000
FXUS62 KCHS 271152
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
752 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL
PREVAIL OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER
MS VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND
AND STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE
TN VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS
ALOFT TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE
NW TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND 8 OR 9 AM...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN
TODAY.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW DURING THE MID AND
LATE AFTERNOON HOURS. GIVEN A STEERING MOTION TOWARD THE EAST/NE
AT 40-50 MPH THE AMOUNT OF RAIN ON AVERAGE LOOKS TO BE LESS THAN
1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 20-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 15-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANOMALOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST MAJORITY OF
TODAY WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE. A BAND OF
NUMEROUS TO WIDESPREAD SHOWERS AND MAYBE A FEW T-STORMS WILL MOVE
THROUGH THE  AREA IN ASSOCIATION WITH A STRONG COLD FRONT FROM
MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD OF
IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD FRONT
AS DRIER AIR STEADILY WORKS ITS WAY IN.

WESTERLY WINDS WILL BECOME GUSTY FOR THIS AFTERNOON AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE CYCLONIC CIRCULATION AROUND THE COLD FRONT. WINDS WILL PEAK
AROUND 20 KT AT KCHS AND AROUND 25 KT AT KSAV FOR SEVERAL HOURS
LATE IN THE DAY BEHIND THE DEPARTING COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...PATCHY SEA FOG IS STILL EVIDENT BASED ON GOES-E
SATELLITE PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS
VEER TO WEST AND SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED
THAT A FEW T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND
AFTERNOON HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
     EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...





000
FXUS62 KCHS 271152
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
752 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL
PREVAIL OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER
MS VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND
AND STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE
TN VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS
ALOFT TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE
NW TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND 8 OR 9 AM...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN
TODAY.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW DURING THE MID AND
LATE AFTERNOON HOURS. GIVEN A STEERING MOTION TOWARD THE EAST/NE
AT 40-50 MPH THE AMOUNT OF RAIN ON AVERAGE LOOKS TO BE LESS THAN
1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 20-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 15-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANOMALOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST MAJORITY OF
TODAY WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE. A BAND OF
NUMEROUS TO WIDESPREAD SHOWERS AND MAYBE A FEW T-STORMS WILL MOVE
THROUGH THE  AREA IN ASSOCIATION WITH A STRONG COLD FRONT FROM
MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD OF
IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD FRONT
AS DRIER AIR STEADILY WORKS ITS WAY IN.

WESTERLY WINDS WILL BECOME GUSTY FOR THIS AFTERNOON AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE CYCLONIC CIRCULATION AROUND THE COLD FRONT. WINDS WILL PEAK
AROUND 20 KT AT KCHS AND AROUND 25 KT AT KSAV FOR SEVERAL HOURS
LATE IN THE DAY BEHIND THE DEPARTING COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...PATCHY SEA FOG IS STILL EVIDENT BASED ON GOES-E
SATELLITE PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS
VEER TO WEST AND SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED
THAT A FEW T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND
AFTERNOON HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
     EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...




000
FXUS62 KCHS 271152
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
752 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL
PREVAIL OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER
MS VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND
AND STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE
TN VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS
ALOFT TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE
NW TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND 8 OR 9 AM...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN
TODAY.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW DURING THE MID AND
LATE AFTERNOON HOURS. GIVEN A STEERING MOTION TOWARD THE EAST/NE
AT 40-50 MPH THE AMOUNT OF RAIN ON AVERAGE LOOKS TO BE LESS THAN
1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 20-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 15-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANOMALOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST MAJORITY OF
TODAY WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE. A BAND OF
NUMEROUS TO WIDESPREAD SHOWERS AND MAYBE A FEW T-STORMS WILL MOVE
THROUGH THE  AREA IN ASSOCIATION WITH A STRONG COLD FRONT FROM
MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD OF
IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD FRONT
AS DRIER AIR STEADILY WORKS ITS WAY IN.

WESTERLY WINDS WILL BECOME GUSTY FOR THIS AFTERNOON AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE CYCLONIC CIRCULATION AROUND THE COLD FRONT. WINDS WILL PEAK
AROUND 20 KT AT KCHS AND AROUND 25 KT AT KSAV FOR SEVERAL HOURS
LATE IN THE DAY BEHIND THE DEPARTING COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...PATCHY SEA FOG IS STILL EVIDENT BASED ON GOES-E
SATELLITE PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS
VEER TO WEST AND SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED
THAT A FEW T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND
AFTERNOON HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
     EVENING FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ354.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...





000
FXUS62 KCHS 271129
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
729 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL
PREVAIL OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER
MS VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND
AND STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE
TN VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS
ALOFT TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE
NW TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND 8 OR 9 AM...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN
TODAY.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW DURING THE MID AND
LATE AFTERNOON HOURS. GIVEN A STEERING MOTION TOWARD THE EAST/NE
AT 40-50 MPH THE AMOUNT OF RAIN ON AVERAGE LOOKS TO BE LESS THAN
1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 20-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 15-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANOMALOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST MAJORITY OF
TODAY WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE. A BAND OF
NUMEROUS TO WIDESPREAD SHOWERS AND MAYBE A FEW T-STORMS WILL MOVE
THROUGH THE  AREA IN ASSOCIATION WITH A STRONG COLD FRONT FROM
MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD OF
IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD FRONT
AS DRIER AIR STEADILY WORKS ITS WAY IN.

WESTERLY WINDS WILL BECOME GUSTY FOR THIS AFTERNOON AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE CYCLONIC CIRCULATION AROUND THE COLD FRONT. WINDS WILL PEAK
AROUND 20 KT AT KCHS AND AROUND 25 KT AT KSAV FOR SEVERAL HOURS
LATE IN THE DAY BEHIND THE DEPARTING COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...PATCHY SEA FOG IS STILL EVIDENT BASED ON GOES-E
SATELLITE PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS
VEER TO WEST AND SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED
THAT A FEW T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND
AFTERNOON HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
     EVENING FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...




000
FXUS62 KCHS 271129
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
729 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL
PREVAIL OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER
MS VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND
AND STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE
TN VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS
ALOFT TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE
NW TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND 8 OR 9 AM...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN
TODAY.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW DURING THE MID AND
LATE AFTERNOON HOURS. GIVEN A STEERING MOTION TOWARD THE EAST/NE
AT 40-50 MPH THE AMOUNT OF RAIN ON AVERAGE LOOKS TO BE LESS THAN
1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 20-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 15-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANOMALOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MVFR CONDITIONS AT BOTH TERMINALS THROUGH THE VAST MAJORITY OF
TODAY WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE. A BAND OF
NUMEROUS TO WIDESPREAD SHOWERS AND MAYBE A FEW T-STORMS WILL MOVE
THROUGH THE  AREA IN ASSOCIATION WITH A STRONG COLD FRONT FROM
MIDDAY THROUGH LATE AFTERNOON. WHILE THERE MIGHT BE A PERIOD OF
IFR WEATHER...MVFR CONDITIONS ARE MUCH MORE LIKELY TO OCCUR.
CONDITIONS WILL IMPROVE BACK TO VFR TONIGHT BEHIND THE COLD FRONT
AS DRIER AIR STEADILY WORKS ITS WAY IN.

WESTERLY WINDS WILL BECOME GUSTY FOR THIS AFTERNOON AS MIXING
HEIGHTS CLIMB AND THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO
THE CYCLONIC CIRCULATION AROUND THE COLD FRONT. WINDS WILL PEAK
AROUND 20 KT AT KCHS AND AROUND 25 KT AT KSAV FOR SEVERAL HOURS
LATE IN THE DAY BEHIND THE DEPARTING COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...PATCHY SEA FOG IS STILL EVIDENT BASED ON GOES-E
SATELLITE PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS
VEER TO WEST AND SCOUR OUT THE FOG. MARINERS ARE ALSO ADVISED
THAT A FEW T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND
AFTERNOON HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
     EVENING FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...





000
FXUS62 KCHS 270944
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
544 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL
PREVAIL OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER
MS VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND
AND STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE
TN VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS
ALOFT TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE
NW TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND 8 OR 9 AM...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN
TODAY.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW DURING THE MID AND
LATE AFTERNOON HOURS. GIVEN A STEERING MOTION TOWARD THE EAST/NE
AT 40-50 MPH THE AMOUNT OF RAIN ON AVERAGE LOOKS TO BE LESS THAN
1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 15-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 10-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANOMOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
KCHS...VFR CONDITIONS WILL ONLY BE TEMPORARY THIS MORNING AS
FLIGHT RESTRICTIONS WILL RESULT FROM DEVELOPING STRATUS CLOUDS
THAT DROP US INTO THE MVFR RANGE BY DAYBREAK. ADDITIONAL SUB-VFR
CONDITIONS ALONG WITH SHOWERS AND MAYBE AN ISOLATED T-STORM WILL
ACCOMPANY A COLD FRONT...AS IT MOVES TOWARD AND THROUGH THE
AIRFIELD DURING THE LATE MORNING AND AFTERNOON. WEST AND NW WINDS
WILL BE GUSTY AT TIMES...PEAKING AROUND 20 KT...BEFORE FADING WITH
SUNSET. VFR CONDITIONS WILL RETURN TONIGHT BEHIND THE EXITING COLD
FRONT...ALTHOUGH A FEW SHOWERS ARE STILL POSSIBLE AS STRONG ENERGY
ALOFT SWINGS THROUGH.

KSAV...THE AIRPORT WILL TEETER BACK AND FORTH FROM VFR TO MVFR
THIS MORNING...ALTHOUGH EVENTUALLY MVFR WILL PREVAIL. AFTER 15Z
SHOWERS AND MAYBE A T-STORM MOVE THROUGH IN ASSOCIATION WITH A
STRONG COLD FRONT...BEFORE VFR WEATHER FINALLY RETURNS LATE
TODAY AND PERSISTS INTO TONIGHT BEHIND THE COLD FRONT. GUSTY
WESTERLY WINDS WILL PREVAIL DURING MUCH OF THE DAYLIGHT
HOURS...PEAKING AT 20-25 KT IN THE AFTERNOON IN WAKE OF THE COLD
FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...SEA FOG IS STILL EVIDENT BASED ON GOES-E SATELLITE
PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS VEER TO
WEST AND SCOUR OUT THE FOG. COVERAGE THOUGH DOESN`T APPEAR TO BE
ENOUGH TO JUSTIFY A DENSE FOG ADVISORY. INSTEAD THERE IS A MARINE
WEATHER STATEMENT IN EFFECT. MARINERS ARE ALSO ADVISED THAT A FEW
T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND AFTERNOON
HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
     EVENING FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...





000
FXUS62 KCHS 270944
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
544 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL
PREVAIL OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER
MS VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND
AND STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE
TN VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS
ALOFT TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE
NW TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND 8 OR 9 AM...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN
TODAY.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW DURING THE MID AND
LATE AFTERNOON HOURS. GIVEN A STEERING MOTION TOWARD THE EAST/NE
AT 40-50 MPH THE AMOUNT OF RAIN ON AVERAGE LOOKS TO BE LESS THAN
1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 15-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 10-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANOMOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
KCHS...VFR CONDITIONS WILL ONLY BE TEMPORARY THIS MORNING AS
FLIGHT RESTRICTIONS WILL RESULT FROM DEVELOPING STRATUS CLOUDS
THAT DROP US INTO THE MVFR RANGE BY DAYBREAK. ADDITIONAL SUB-VFR
CONDITIONS ALONG WITH SHOWERS AND MAYBE AN ISOLATED T-STORM WILL
ACCOMPANY A COLD FRONT...AS IT MOVES TOWARD AND THROUGH THE
AIRFIELD DURING THE LATE MORNING AND AFTERNOON. WEST AND NW WINDS
WILL BE GUSTY AT TIMES...PEAKING AROUND 20 KT...BEFORE FADING WITH
SUNSET. VFR CONDITIONS WILL RETURN TONIGHT BEHIND THE EXITING COLD
FRONT...ALTHOUGH A FEW SHOWERS ARE STILL POSSIBLE AS STRONG ENERGY
ALOFT SWINGS THROUGH.

KSAV...THE AIRPORT WILL TEETER BACK AND FORTH FROM VFR TO MVFR
THIS MORNING...ALTHOUGH EVENTUALLY MVFR WILL PREVAIL. AFTER 15Z
SHOWERS AND MAYBE A T-STORM MOVE THROUGH IN ASSOCIATION WITH A
STRONG COLD FRONT...BEFORE VFR WEATHER FINALLY RETURNS LATE
TODAY AND PERSISTS INTO TONIGHT BEHIND THE COLD FRONT. GUSTY
WESTERLY WINDS WILL PREVAIL DURING MUCH OF THE DAYLIGHT
HOURS...PEAKING AT 20-25 KT IN THE AFTERNOON IN WAKE OF THE COLD
FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...SEA FOG IS STILL EVIDENT BASED ON GOES-E SATELLITE
PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS VEER TO
WEST AND SCOUR OUT THE FOG. COVERAGE THOUGH DOESN`T APPEAR TO BE
ENOUGH TO JUSTIFY A DENSE FOG ADVISORY. INSTEAD THERE IS A MARINE
WEATHER STATEMENT IN EFFECT. MARINERS ARE ALSO ADVISED THAT A FEW
T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND AFTERNOON
HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
     EVENING FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...




000
FXUS62 KCHS 270809
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
409 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...A SHORT WAVE PROGRESSING THROUGH THE FORECAST
ZONES WILL KICK INTO THE ATLANTIC AND TAKES THE FIRST BATCH OF
SHOWERS WITH IT AS THEY PROGRESS QUICKLY OFF TO THE NE.
MEANWHILE...LINGERING SEA FOG IS SCRAPING THE IMMEDIATE
COASTLINE...BUT GIVEN STRENGTHENING WIND FIELDS AND A SW FETCH THE
BULK OF THIS PHENOMENA WILL STAY IN THE OCEAN.

FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER MS
VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND AND
STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE TN
VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS ALOFT
TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE NW
TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND DAYBREAK...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW. GIVEN A STEERING
MOTION TOWARD THE EAST/NE AT 40-50 MPH THE AMOUNT OF RAIN ON
AVERAGE LOOKS TO BE LESS THAN 1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 15-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 10-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANAMOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
KCHS...AS A SHORT WAVE PASSES ALONG THE SC COAST OVERNIGHT THERE
WILL BE A SHOWERS PASSING NEARBY OR THROUGH THE TERMINAL.
HOWEVER...ANY FLIGHT RESTRICTIONS WILL RESULT FROM DEVELOPING
STRATUS CLOUDS THAT DROP US INTO THE MVFR AFTER 09Z. ADDITIONAL
SUB-VFR CONDITIONS ALONG WITH SHOWERS AND MAYBE AN ISOLATED
T-STORM WILL ACCOMPANY A COLD FRONT...AS IT MOVES TOWARD AND
THROUGH THE AIRFIELD DURING THE LATE MORNING AND AFTERNOON. WEST
AND NW WINDS WILL BE GUSTY AT TIMES...PEAKING AROUND 20
KT...BEFORE FADING WITH SUNSET. VFR CONDITIONS WILL RETURN TONIGHT
BEHIND THE EXITING COLD FRONT...ALTHOUGH A FEW SHOWERS ARE STILL
POSSIBLE AS STRONG ENERGY ALOFT SWINGS THROUGH.

KSAV...THE AIRPORT WILL TEETER BETWEEN VFR AND MVFR THIS
MORNING...BEFORE A BETTER CHANCE FOR MVFR CONDITIONS DEVELOPS
AFTER 15Z AS SHOWERS AND MAYBE A T-STORM MOVE THROUGH IN
ASSOCIATION WITH A STRONG COLD FRONT. VFR WEATHER WILL FINALLY
RETURN LATE FRIDAY AND PERSIST INTO FRIDAY NIGHT BEHIND THE COLD
FRONT. GUSTY WESTERLY WINDS WILL PREVAIL DURING MUCH OF THE
DAYLIGHT HOURS FRIDAY...PEAKING AT 20-25 KT IN THE AFTERNOON IN
WAKE OF THE COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...SEA FOG IS STILL EVIDENT BASED ON GOES-E SATELLITE
PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS VEER TO
WEST AND SCOUR OUT THE FOG. COVERAGE THOUGH DOESN`T APPEAR TO BE
ENOUGH TO JUSTIFY A DENSE FOG ADVISORY. INSTEAD THERE IS A MARINE
WEATHER STATEMENT IN EFFECT. MARINERS ARE ALSO ADVISED THAT A FEW
T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND AFTERNOON
HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 5 PM EDT THIS
     AFTERNOON FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...





000
FXUS62 KCHS 270809
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
409 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...A SHORT WAVE PROGRESSING THROUGH THE FORECAST
ZONES WILL KICK INTO THE ATLANTIC AND TAKES THE FIRST BATCH OF
SHOWERS WITH IT AS THEY PROGRESS QUICKLY OFF TO THE NE.
MEANWHILE...LINGERING SEA FOG IS SCRAPING THE IMMEDIATE
COASTLINE...BUT GIVEN STRENGTHENING WIND FIELDS AND A SW FETCH THE
BULK OF THIS PHENOMENA WILL STAY IN THE OCEAN.

FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER MS
VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND AND
STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE TN
VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS ALOFT
TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE NW
TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND DAYBREAK...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW. GIVEN A STEERING
MOTION TOWARD THE EAST/NE AT 40-50 MPH THE AMOUNT OF RAIN ON
AVERAGE LOOKS TO BE LESS THAN 1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 15-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 10-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANAMOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
KCHS...AS A SHORT WAVE PASSES ALONG THE SC COAST OVERNIGHT THERE
WILL BE A SHOWERS PASSING NEARBY OR THROUGH THE TERMINAL.
HOWEVER...ANY FLIGHT RESTRICTIONS WILL RESULT FROM DEVELOPING
STRATUS CLOUDS THAT DROP US INTO THE MVFR AFTER 09Z. ADDITIONAL
SUB-VFR CONDITIONS ALONG WITH SHOWERS AND MAYBE AN ISOLATED
T-STORM WILL ACCOMPANY A COLD FRONT...AS IT MOVES TOWARD AND
THROUGH THE AIRFIELD DURING THE LATE MORNING AND AFTERNOON. WEST
AND NW WINDS WILL BE GUSTY AT TIMES...PEAKING AROUND 20
KT...BEFORE FADING WITH SUNSET. VFR CONDITIONS WILL RETURN TONIGHT
BEHIND THE EXITING COLD FRONT...ALTHOUGH A FEW SHOWERS ARE STILL
POSSIBLE AS STRONG ENERGY ALOFT SWINGS THROUGH.

KSAV...THE AIRPORT WILL TEETER BETWEEN VFR AND MVFR THIS
MORNING...BEFORE A BETTER CHANCE FOR MVFR CONDITIONS DEVELOPS
AFTER 15Z AS SHOWERS AND MAYBE A T-STORM MOVE THROUGH IN
ASSOCIATION WITH A STRONG COLD FRONT. VFR WEATHER WILL FINALLY
RETURN LATE FRIDAY AND PERSIST INTO FRIDAY NIGHT BEHIND THE COLD
FRONT. GUSTY WESTERLY WINDS WILL PREVAIL DURING MUCH OF THE
DAYLIGHT HOURS FRIDAY...PEAKING AT 20-25 KT IN THE AFTERNOON IN
WAKE OF THE COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...SEA FOG IS STILL EVIDENT BASED ON GOES-E SATELLITE
PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS VEER TO
WEST AND SCOUR OUT THE FOG. COVERAGE THOUGH DOESN`T APPEAR TO BE
ENOUGH TO JUSTIFY A DENSE FOG ADVISORY. INSTEAD THERE IS A MARINE
WEATHER STATEMENT IN EFFECT. MARINERS ARE ALSO ADVISED THAT A FEW
T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND AFTERNOON
HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 5 PM EDT THIS
     AFTERNOON FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...




000
FXUS62 KCHS 270809
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
409 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...A SHORT WAVE PROGRESSING THROUGH THE FORECAST
ZONES WILL KICK INTO THE ATLANTIC AND TAKES THE FIRST BATCH OF
SHOWERS WITH IT AS THEY PROGRESS QUICKLY OFF TO THE NE.
MEANWHILE...LINGERING SEA FOG IS SCRAPING THE IMMEDIATE
COASTLINE...BUT GIVEN STRENGTHENING WIND FIELDS AND A SW FETCH THE
BULK OF THIS PHENOMENA WILL STAY IN THE OCEAN.

FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER MS
VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND AND
STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE TN
VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS ALOFT
TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE NW
TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND DAYBREAK...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW. GIVEN A STEERING
MOTION TOWARD THE EAST/NE AT 40-50 MPH THE AMOUNT OF RAIN ON
AVERAGE LOOKS TO BE LESS THAN 1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 15-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 10-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANAMOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
KCHS...AS A SHORT WAVE PASSES ALONG THE SC COAST OVERNIGHT THERE
WILL BE A SHOWERS PASSING NEARBY OR THROUGH THE TERMINAL.
HOWEVER...ANY FLIGHT RESTRICTIONS WILL RESULT FROM DEVELOPING
STRATUS CLOUDS THAT DROP US INTO THE MVFR AFTER 09Z. ADDITIONAL
SUB-VFR CONDITIONS ALONG WITH SHOWERS AND MAYBE AN ISOLATED
T-STORM WILL ACCOMPANY A COLD FRONT...AS IT MOVES TOWARD AND
THROUGH THE AIRFIELD DURING THE LATE MORNING AND AFTERNOON. WEST
AND NW WINDS WILL BE GUSTY AT TIMES...PEAKING AROUND 20
KT...BEFORE FADING WITH SUNSET. VFR CONDITIONS WILL RETURN TONIGHT
BEHIND THE EXITING COLD FRONT...ALTHOUGH A FEW SHOWERS ARE STILL
POSSIBLE AS STRONG ENERGY ALOFT SWINGS THROUGH.

KSAV...THE AIRPORT WILL TEETER BETWEEN VFR AND MVFR THIS
MORNING...BEFORE A BETTER CHANCE FOR MVFR CONDITIONS DEVELOPS
AFTER 15Z AS SHOWERS AND MAYBE A T-STORM MOVE THROUGH IN
ASSOCIATION WITH A STRONG COLD FRONT. VFR WEATHER WILL FINALLY
RETURN LATE FRIDAY AND PERSIST INTO FRIDAY NIGHT BEHIND THE COLD
FRONT. GUSTY WESTERLY WINDS WILL PREVAIL DURING MUCH OF THE
DAYLIGHT HOURS FRIDAY...PEAKING AT 20-25 KT IN THE AFTERNOON IN
WAKE OF THE COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...SEA FOG IS STILL EVIDENT BASED ON GOES-E SATELLITE
PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS VEER TO
WEST AND SCOUR OUT THE FOG. COVERAGE THOUGH DOESN`T APPEAR TO BE
ENOUGH TO JUSTIFY A DENSE FOG ADVISORY. INSTEAD THERE IS A MARINE
WEATHER STATEMENT IN EFFECT. MARINERS ARE ALSO ADVISED THAT A FEW
T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND AFTERNOON
HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 5 PM EDT THIS
     AFTERNOON FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...





000
FXUS62 KCHS 270809
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
409 AM EDT FRI MAR 27 2015

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND NORTHWEST THIS
MORNING...PASSING THROUGH THE AREA THIS AFTERNOON. UNSEASONABLY COLD
HIGH PRESSURE WILL PREVAIL THIS WEEKEND. FROST AND AN INLAND FREEZE
COULD OCCUR LATE SATURDAY NIGHT INTO EARLY SUNDAY. HIGH PRESSURE
WILL SHIFT SOUTH OF THE REGION MONDAY...THEN A COLD FRONT WILL
MOVE THROUGH LATE MONDAY INTO EARLY TUESDAY. THE COLD FRONT WILL
STALL THEN WILL LIFT NORTH AS A WARM FRONT AS WARMER HIGH PRESSURE
BUILDS OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER
COLD FRONT COULD APPROACH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...A SHORT WAVE PROGRESSING THROUGH THE FORECAST
ZONES WILL KICK INTO THE ATLANTIC AND TAKES THE FIRST BATCH OF
SHOWERS WITH IT AS THEY PROGRESS QUICKLY OFF TO THE NE.
MEANWHILE...LINGERING SEA FOG IS SCRAPING THE IMMEDIATE
COASTLINE...BUT GIVEN STRENGTHENING WIND FIELDS AND A SW FETCH THE
BULK OF THIS PHENOMENA WILL STAY IN THE OCEAN.

FOR TODAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH A SHORT WAVE OVER THE LOWER MS
VALLEY THAT PASSES INTO THE SE STATES BY LATE...WHILE A SECOND AND
STRONGER SHORT WAVE WILL DIVE FROM THE MID MS VALLEY INTO THE TN
VALLEY IN THE AFTERNOON. THIS TRANSITION WILL CAUSE HEIGHTS ALOFT
TO STEADILY FALL AND WILL SHOVE A STRONG COLD FRONT INTO THE NW
TIER DURING THE LATE MORNING...TOWARD OUR COASTAL CORRIDOR BY
EARLY OR MID AFTERNOON...AND INTO THE ATLANTIC THEREAFTER. SHOWERS
ARE ORGANIZING IN GEORGIA AND ALABAMA AND WILL DEVELOP INTO A
SWATH OF SHOWERS THAT WILL ADVANCE AHEAD OF THE COLD FRONT AND
ENTER OUR WEST/NW SECTIONS BY AROUND DAYBREAK...SWEEPING RATHER
QUICKLY EASTWARD AND PROVIDING EVERYONE WITH A FEW HOURS OF RAIN.

LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH A 150 KT OR GREATER
UPPER JET WILL HAVE PLENTY OF MOISTURE TO WORK WITH AS PWATS ARE
BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE NORMAL. AS A RESULT WE
ARE SHOWING 80 POPS IN ALL COUNTIES...BUT ONCE RADAR TRENDS ARE
BETTER ILLUSTRATED WE MIGHT BE ABLE TO CARRY 100 POPS FOR A GOOD
CHUNK OF THE CWFA. RAIN CHANCES WILL DROP OFF CONSIDERABLY BEHIND
THE FRONT AS DRIER AIR PUNCHES IN FROM THE SW. GIVEN A STEERING
MOTION TOWARD THE EAST/NE AT 40-50 MPH THE AMOUNT OF RAIN ON
AVERAGE LOOKS TO BE LESS THAN 1/4 OR 1/3 INCH.

WITH CONSIDERABLE CLOUD COVER IN PLACE THE THERMODYNAMIC PROFILE
IS FAR FROM IMPRESSIVE. BUT GIVEN SOME NEGATIVE LIFTED
INDICES...MUCAPES AS MUCH AS 300-500 J/KG AND O-6 KM BULK SHEAR OF
75 KT OR SO WE FELT COMPELLED TO CARRY A SLIGHT CHANCE OF
THUNDERSTORMS.

DEEPER MIXING WILL DEVELOP ACROSS SE GA DURING THE MID AND LATE
AFTERNOON AS THE DRIER AIR WORKS IT/S WAY IN AND PRESSURES START
TO CLIMB WE ANTICIPATE GUSTY WEST/NW WINDS TO RISE INTO THE 15-25
MPH RANGE. FURTHER NORTH IN SC THE CONDITIONS ARE NOT QUITE AS
FAVORABLE...BUT STILL WINDS WILL PEAK AT 10-20 MPH.

TEMPS ARE OFF TO A WARM START BY LATE MARCH STANDARDS AND WITH
SEVERAL HOURS OF WARM ADVECTION THIS WILL HELP IN NEGATING THE
EXTENSIVE CLOUD COVER AND LACK OF INSOLATION. THIS SHOULD BUMP US
INTO THE UPPER 60S AND LOWER 70S MOST COMMUNITIES...ALTHOUGH A FEW
MID 70S MIGHT BE ACHIEVED SOUTH OF SAVANNAH.

TONIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-10Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL ARRIVE BEHIND THIS
FEATURE IT WON/T GET HERE SOON ENOUGH TO PRODUCE ANYTHING MORE
THAN ISOLATED TO SCATTERED SHOWERS. HOWEVER...STEEP MID LEVEL
LAPSE RATES WITH 500 MB TEMPS AROUND -26 OR -27C COULD ALLOW FOR
SOME SOFT HAIL OR GRAUPEL TO OCCUR IN A FEW OF THE SHOWERS AS THE
SHORT WAVE SWINGS THROUGH. 850 MB TEMPS FALL TO AN ANAMOUSLY COLD
-1C SOUTH AND -4C NORTH AND WILL ALLOW FOR TEMPS TO PLUNGE DOWN
INTO THE UPPER 30S AND LOWER 40S BY DAYBREAK SATURDAY. THIS WILL
BE ABOUT 20-25F COLDER THAN THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY MORNING...A STRONG SHORTWAVE EMBEDDED WITHIN A LONGWAVE
TROUGH ALOFT 2 TO 3 STANDARD DEVIATIONS DEEPER THAN NORMAL FOR LATE
MARCH WILL PUSH THROUGH THE REGION. MODEL SOUNDINGS SUGGEST A WINDOW
OF OPPORTUNITY FOR CONVECTION SUPPORTED BY VERY COLD AIR
ALOFT/STEEPENING MID-LEVEL LAPSE RATES...BEFORE A SUBSIDENCE
INVERSION DEVELOPS SATURDAY AFTERNOON. HOWEVER...THE PROBABILITY FOR
ANY MEASURABLE PRECIPITATION IN THE FORM OF RAIN SHOWERS AND EVEN
ISOLATED GRAUPEL/LIGHTNING REMAINS TOO LOW...BELOW 15 PERCENT...TO
JUSTIFY A MENTION WITHIN PUBLIC FORECASTS. WILL CONTINUE TO ASSESS.

OTHERWISE...THE MAIN STORY THIS WEEKEND WILL CENTER ON UNSEASONABLY
COOL TEMPERATURES...STRUGGLING TO REACH 60F MOST AREAS EACH
DAY...EXCEPT IN THE LOWER/MID 60S NEAR THE ALTAMAHA RIVER. THESE
HIGH TEMPERATURES WILL AVERAGE 10-14F BELOW NORMAL.

OF GREATEST IMPORT...COLD HIGH PRESSURE WILL SHIFT SOUTHWARD/TOWARD
THE REGION SATURDAY NIGHT/EARLY SUNDAY. THE POTENTIAL FOR BOUNDARY
LAYER DECOUPLING/EFFICIENT RADIATIONAL COOLING WILL INCREASE...AND
TEMPERATURES ARE EXPECTED TO FALL INTO THE 30S AWAY FROM THE
IMMEDIATE COAST. IN FACT...A COUPLE OF HOURS OF SUBFREEZING
TEMPERATURES COULD OCCUR WELL INLAND ESPECIALLY IF WINDS BECOME
CALM. PER COLLABORATION WITH WFOS CAE AND ILM OPTED NOT TO ISSUE
LATE 4TH PERIOD/EARLY 5TH PERIOD FREEZE WATCHES. HOWEVER...ADDED A
MENTION OF FROST AWAY FROM THE COAST...AND FREEZE WATCHES/WARNINGS
AND/OR FROST ADVISORIES COULD EVENTUALLY BE REQUIRED.

MONDAY...THE NEXT COLD FRONT WILL APPROACH THE REGION. AHEAD OF THIS
FEATURE...TEMPERATURES SHOULD RECOVER INTO THE UPPER 60S/LOWER 70S.
ALSO...AT LEAST SLIGHT CHANCE/CHANCE POPS AS AN AXIS OF FORCING FOR
ASCENT/AN ASSOCIATED BAND OF ENHANCED MOISTURE ADVANCES INTO THE
REGION FROM THE NORTHWEST. ISOLATED THUNDERSTORMS CANNOT BE RULED
OUT...BUT INSTABILITY APPEARS MARGINAL THUS OPTED NOT TO ADD A
MENTION OF THUNDER WITHIN THE FRIDAY MORNING FORECAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE LATE MONDAY/EARLY TUESDAY COLD FRONT WILL WEAKEN...STALL THEN
WILL EITHER DISSIPATE OR PUSH NORTH AS A WARM FRONT. THUS...A
WARMING TREND IS EXPECTED WITH TEMPERATURES NEAR NORMAL TUESDAY
THEN ABOVE NORMAL...AT LEAST IN THE MID/UPPER 70S WEDNESDAY
THROUGH LATE WEEK. MORE SUNSHINE THAN EXPECTED WEDNESDAY WILL
SUPPORT HIGHS AROUND 80F. THE NEXT OPPORTUNITY FOR SIGNIFICANT
PRECIPITATION WILL OCCUR AFTER WEDNESDAY AS A SOUTHERN SHORTWAVE
TROUGH PUSHES THROUGH THE REGION. TIMING REMAINS UNCERTAIN...POPS
COULD INCREASE AS EARLY AS LATER WEDNESDAY OR WEDNESDAY NIGHT AND
COULD LINGER INTO FRIDAY AS ANOTHER WEAK COLD FRONT ADVANCES INTO
THE REGION...BUT HIGHEST POPS...CAPPED AT CHANCE FOR NOW...ARE IN
ORDER THURSDAY INTO THURSDAY NIGHT. ALSO...MODELS DEPICT
SUFFICIENT INSTABILITY FOR JUSTIFY A MENTION OF THUNDER THURSDAY
AND FRIDAY.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
KCHS...AS A SHORT WAVE PASSES ALONG THE SC COAST OVERNIGHT THERE
WILL BE A SHOWERS PASSING NEARBY OR THROUGH THE TERMINAL.
HOWEVER...ANY FLIGHT RESTRICTIONS WILL RESULT FROM DEVELOPING
STRATUS CLOUDS THAT DROP US INTO THE MVFR AFTER 09Z. ADDITIONAL
SUB-VFR CONDITIONS ALONG WITH SHOWERS AND MAYBE AN ISOLATED
T-STORM WILL ACCOMPANY A COLD FRONT...AS IT MOVES TOWARD AND
THROUGH THE AIRFIELD DURING THE LATE MORNING AND AFTERNOON. WEST
AND NW WINDS WILL BE GUSTY AT TIMES...PEAKING AROUND 20
KT...BEFORE FADING WITH SUNSET. VFR CONDITIONS WILL RETURN TONIGHT
BEHIND THE EXITING COLD FRONT...ALTHOUGH A FEW SHOWERS ARE STILL
POSSIBLE AS STRONG ENERGY ALOFT SWINGS THROUGH.

KSAV...THE AIRPORT WILL TEETER BETWEEN VFR AND MVFR THIS
MORNING...BEFORE A BETTER CHANCE FOR MVFR CONDITIONS DEVELOPS
AFTER 15Z AS SHOWERS AND MAYBE A T-STORM MOVE THROUGH IN
ASSOCIATION WITH A STRONG COLD FRONT. VFR WEATHER WILL FINALLY
RETURN LATE FRIDAY AND PERSIST INTO FRIDAY NIGHT BEHIND THE COLD
FRONT. GUSTY WESTERLY WINDS WILL PREVAIL DURING MUCH OF THE
DAYLIGHT HOURS FRIDAY...PEAKING AT 20-25 KT IN THE AFTERNOON IN
WAKE OF THE COLD FRONT.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS POSSIBLE IN SHOWERS
MONDAY. OTHERWISE...MAINLY VFR.

&&

.MARINE...
TODAY...A STRONG COLD FRONT WILL HEAD THROUGH THE SE STATES THIS
MORNING...REACHING THE COASTAL WATERS THIS AFTERNOON...PASSING TO
THE EAST/SE AFTER 2 OR 3 PM. DESPITE SOME MARINE LAYERING EFFECTS
WITHIN THE WARM ADVECTION...A FAIRLY DECENT CYCLONIC PRESSURE
GRADIENT WILL ASSIST IN BUMPING SW WINDS UP INTO THE 15 TO 20 KT
RANGE. THERE WILL EVEN BE FREQUENT GUSTS TO NEAR 25 KT ON THE
OUTER GA WATERS AND INFREQUENT GUSTS TO 25 KT ON THE CHARLESTON
COUNTY ATLANTIC WATERS. THIS WILL BE ENOUGH TO CAUSE SEAS TO BUILD
TO 6 FT ON THESE AFOREMENTIONED MARINE ZONES...AND IT IS HERE
WHERE WE HAVE OUR SMALL CRAFT ADVISORIES. THE OTHER WATERS WILL
STAY JUST BELOW ANY ADVISORY CONDITIONS THROUGH THE DAY.
MEANWHILE...SEA FOG IS STILL EVIDENT BASED ON GOES-E SATELLITE
PRODUCTS AND WILL PERSIST INTO THE AFTERNOON UNTIL WINDS VEER TO
WEST AND SCOUR OUT THE FOG. COVERAGE THOUGH DOESN`T APPEAR TO BE
ENOUGH TO JUSTIFY A DENSE FOG ADVISORY. INSTEAD THERE IS A MARINE
WEATHER STATEMENT IN EFFECT. MARINERS ARE ALSO ADVISED THAT A FEW
T-STORMS WILL MOVE THROUGH DURING THE LATE MORNING AND AFTERNOON
HOURS.

TONIGHT...STEADY ISALLOBARIC PRESSURE RISES WILL DEVELOP BEHIND
THE DEPARTING COLD FRONT...KEEPING NW WINDS ELEVATED. AS A RESULT
WE HAVE HOISTED ANOTHER SMALL CRAFT ADVISORY ON THE AMZ354 WHERE
FREQUENT GUSTS TO 25 KT ARE ANTICIPATED WITHIN THE COLD
ADVECTION. THIS WILL GO ALONG WITH AN ALREADY PRE-EXISTING
ADVISORY ON THE OUTER GA WATERS FOR SEAS OF 6 FT AND GUSTS OF 25
OR 30 KT. WE/LL BE CLOSE TO ADVISORY CONDITIONS ON THE SC
ATLANTIC WATERS...AND WE STILL MAY NEED TO RAISE THE FLAGS AT A
LATER TIME.

SATURDAY THROUGH WEDNESDAY...ELEVATED OFFSHORE WINDS AND ASSOCIATED
SMALL CRAFT ADVISORY CONDITIONS SHOULD RELAX AS HIGH PRESSURE SHIFTS
TOWARD THE WATERS SATURDAY AFTERNOON THROUGH SATURDAY EVENING.
HOWEVER...LATE SATURDAY NIGHT INTO SUNDAY GUIDANCE DEPICTS A SURGE
OF NORTHEAST WINDS WHICH COULD PRODUCE A FEW HOURS OF LOCALIZED
SMALL CRAFT ADVISORY CONDITIONS. THEN...AS HIGH PRESSURE SHIFTS
SOUTH OF THE WATERS SUNDAY NIGHT INTO MONDAY...ONSHORE WINDS 10 KT
OR LESS SHOULD VEER TOWARD THE SOUTHWEST AND INCREASE IN
SPEED...ESPECIALLY MONDAY AHEAD OF AN APPROACHING COLD FRONT.

AFTER A WEAKENING COLD FRONT PASSES THEN STALLS MONDAY NIGHT OR
EARLY TUESDAY...WINDS AND SEAS WILL REMAIN WELL BELOW SCA LEVELS
THROUGH MID WEEK.

SEAS WILL CHANGE DURING VIRTUALLY EACH PERIOD OF THIS FORECAST. SEAS
WILL BEGIN SATURDAY AT 2-4 FT WITHIN NEARSHORE WATERS AND 4-6 FT
BEYOND 20 NM WILL SUBSIDE TO 1-3 FT BY SATURDAY EVENING...THEN WILL
BUILD TO 2-4 FT AND PERHAPS AS HIGH AS 5 FT BEYOND 20 NM LATE
SATURDAY NIGHT THROUGH SUNDAY MORNING. SUNDAY NIGHT...SEAS SHOULD
SUBSIDE TO 1-2 FT...THEN INCREASING WINDS WILL SUPPORT SEAS BUILDING
TO AT LEAST 3-5 FT MONDAY. SEAS SHOULD THEN SUBSIDE TO 1-2 FT AGAIN
BY MID WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 5 PM EDT THIS
     AFTERNOON FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...




000
FXUS62 KCHS 270529
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
129 AM EDT FRI MAR 27 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WE ADJUSTED POPS SLIGHTLY TO ACCOUNT FOR THE SHORT WAVE PUSHING
THROUGH THE NEARBY ATLANTIC FROM SW TO NE OVERNIGHT. THE BULK OF
THE ACTIVITY WILL STAY OFFSHORE...BUT WE HAVE SLIGHT CHANCE AND
CHANCES POPS AS A RESULT...HIGHEST ON THE SC COAST.

TEMPS SHOULD BE LINGERING IN THE 60S OVERNIGHT WITH DEW POINTS
REMAINING ELEVATED IN THE LOWER 60S MOST AREAS. LOW LEVEL WIND
FIELDS SHOULD INCREASE OVERNIGHT WHICH DO NOT FAVOR FOG HOWEVER
THE RICH LOW LEVEL MOISTURE CONTENT MAY RESULT IN SOME FORM OF
ADVECTION STRATUS FROM THE GULF OR ATLC OVERNIGHT...PLUS NEARBY
SEA FOG OVER THE ATLANTIC WILL SKIRT COASTAL SECTIONS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
KCHS...AS A SHORT WAVE PASSES ALONG THE SC COAST OVERNIGHT THERE
WILL BE A SHOWERS PASSING NEARBY OR THROUGH THE TERMINAL.
HOWEVER...ANY FLIGHT RESTRICTIONS WILL RESULT FROM DEVELOPING
STRATUS CLOUDS THAT DROP US INTO THE MVFR AFTER 09Z. ADDITIONAL
SUB-VFR CONDITIONS ALONG WITH SHOWERS AND MAYBE AN ISOLATED
T-STORM WILL ACCOMPANY A COLD FRONT...AS IT MOVES TOWARD AND
THROUGH THE AIRFIELD DURING THE LATE MORNING AND AFTERNOON. WEST
AND NW WINDS WILL BE GUSTY AT TIMES...PEAKING AROUND 20
KT...BEFORE FADING WITH SUNSET. VFR CONDITIONS WILL RETURN TONIGHT
BEHIND THE EXITING COLD FRONT...ALTHOUGH A FEW SHOWERS ARE STILL
POSSIBLE AS STRONG ENERGY ALOFT SWINGS THROUGH.

KSAV...IFR CEILINGS WILL PREVAIL AT THE AIRFIELD INTO FRIDAY
MORNING...WITH MOISTURE TRAPPED UNDERNEATH THE INVERSION AROUND
600 FT. HOWEVER...ISOLATED SHOWERS WILL SKIRT NEARBY AND COULD
OCCASIONALLY ALLOW FOR A TEMPORARY IMPROVEMENT BACK INTO THE MVFR
CATEGORY. A BETTER CHANCE FOR MVFR CONDITIONS THOUGH WILL PREVAIL
DURING AFTER 13Z AS THE INVERSION BREAKS AND SHOWERS AND MAYBE A
T-STORM MOVE THROUGH IN ASSOCIATION WITH A STRONG COLD FRONT. VFR
WEATHER WILL FINALLY RETURN LATE FRIDAY AND PERSIST INTO FRIDAY
NIGHT BEHIND THE COLD FRONT. GUSTY WESTERLY WINDS WILL PREVAIL
DURING MUCH OF THE DAYLIGHT HOURS FRIDAY...PEAKING AT 20-25 KT IN
THE AFTERNOON IN WAKE OF THE COLD FRONT.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
OVERNIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF
AN APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND
GUSTS AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WERE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.
SEA FOG IS STILL PREVALENT AS PER GOES-E SATELLITE IMAGERY AND
COASTAL OBSERVATIONS. SOME OF THE FOG WILL BE LOCALLY DENSE...BUT
INCREASING WINDS WILL LIKELY PREVENT IT FROM BECOMING TOO
WIDESPREAD AND THUS NO DENSE FOG ADVISORY AT THIS TIME.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 1 PM EDT
     SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM EDT
     THIS AFTERNOON FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...





000
FXUS62 KCHS 270529
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
129 AM EDT FRI MAR 27 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WE ADJUSTED POPS SLIGHTLY TO ACCOUNT FOR THE SHORT WAVE PUSHING
THROUGH THE NEARBY ATLANTIC FROM SW TO NE OVERNIGHT. THE BULK OF
THE ACTIVITY WILL STAY OFFSHORE...BUT WE HAVE SLIGHT CHANCE AND
CHANCES POPS AS A RESULT...HIGHEST ON THE SC COAST.

TEMPS SHOULD BE LINGERING IN THE 60S OVERNIGHT WITH DEW POINTS
REMAINING ELEVATED IN THE LOWER 60S MOST AREAS. LOW LEVEL WIND
FIELDS SHOULD INCREASE OVERNIGHT WHICH DO NOT FAVOR FOG HOWEVER
THE RICH LOW LEVEL MOISTURE CONTENT MAY RESULT IN SOME FORM OF
ADVECTION STRATUS FROM THE GULF OR ATLC OVERNIGHT...PLUS NEARBY
SEA FOG OVER THE ATLANTIC WILL SKIRT COASTAL SECTIONS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
KCHS...AS A SHORT WAVE PASSES ALONG THE SC COAST OVERNIGHT THERE
WILL BE A SHOWERS PASSING NEARBY OR THROUGH THE TERMINAL.
HOWEVER...ANY FLIGHT RESTRICTIONS WILL RESULT FROM DEVELOPING
STRATUS CLOUDS THAT DROP US INTO THE MVFR AFTER 09Z. ADDITIONAL
SUB-VFR CONDITIONS ALONG WITH SHOWERS AND MAYBE AN ISOLATED
T-STORM WILL ACCOMPANY A COLD FRONT...AS IT MOVES TOWARD AND
THROUGH THE AIRFIELD DURING THE LATE MORNING AND AFTERNOON. WEST
AND NW WINDS WILL BE GUSTY AT TIMES...PEAKING AROUND 20
KT...BEFORE FADING WITH SUNSET. VFR CONDITIONS WILL RETURN TONIGHT
BEHIND THE EXITING COLD FRONT...ALTHOUGH A FEW SHOWERS ARE STILL
POSSIBLE AS STRONG ENERGY ALOFT SWINGS THROUGH.

KSAV...IFR CEILINGS WILL PREVAIL AT THE AIRFIELD INTO FRIDAY
MORNING...WITH MOISTURE TRAPPED UNDERNEATH THE INVERSION AROUND
600 FT. HOWEVER...ISOLATED SHOWERS WILL SKIRT NEARBY AND COULD
OCCASIONALLY ALLOW FOR A TEMPORARY IMPROVEMENT BACK INTO THE MVFR
CATEGORY. A BETTER CHANCE FOR MVFR CONDITIONS THOUGH WILL PREVAIL
DURING AFTER 13Z AS THE INVERSION BREAKS AND SHOWERS AND MAYBE A
T-STORM MOVE THROUGH IN ASSOCIATION WITH A STRONG COLD FRONT. VFR
WEATHER WILL FINALLY RETURN LATE FRIDAY AND PERSIST INTO FRIDAY
NIGHT BEHIND THE COLD FRONT. GUSTY WESTERLY WINDS WILL PREVAIL
DURING MUCH OF THE DAYLIGHT HOURS FRIDAY...PEAKING AT 20-25 KT IN
THE AFTERNOON IN WAKE OF THE COLD FRONT.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
OVERNIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF
AN APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND
GUSTS AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WERE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.
SEA FOG IS STILL PREVALENT AS PER GOES-E SATELLITE IMAGERY AND
COASTAL OBSERVATIONS. SOME OF THE FOG WILL BE LOCALLY DENSE...BUT
INCREASING WINDS WILL LIKELY PREVENT IT FROM BECOMING TOO
WIDESPREAD AND THUS NO DENSE FOG ADVISORY AT THIS TIME.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 1 PM EDT
     SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM EDT
     THIS AFTERNOON FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS62 KCHS 270449
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1249 AM EDT FRI MAR 27 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WE ADJUSTED POPS SLIGHTLY TO ACCOUNT FOR THE SHORT WAVE PUSHING
THROUGH THE NEARBY ATLANTIC FROM SW TO NE OVERNIGHT. THE BULK OF
THE ACTIVITY WILL STAY OFFSHORE...BUT WE HAVE SLIGHT CHANCE AND
CHANCES POPS AS A RESULT...HIGHEST ON THE SC COAST.

TEMPS SHOULD BE LINGERING IN THE 60S OVERNIGHT WITH DEW POINTS
REMAINING ELEVATED IN THE LOWER 60S MOST AREAS. LOW LEVEL WIND
FIELDS SHOULD INCREASE OVERNIGHT WHICH DO NOT FAVOR FOG HOWEVER
THE RICH LOW LEVEL MOISTURE CONTENT MAY RESULT IN SOME FORM OF
ADVECTION STRATUS FROM THE GULF OR ATLC OVERNIGHT...PLUS NEARBY
SEA FOG OVER THE ATLANTIC WILL SKIRT COASTAL SECTIONS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH THE EVENING...WITH INCREASING CHANCES FOR MVFR/IFR
CIGS LATER TONIGHT...ESPECIALLY CLOSING IN ON DAYBREAK. IN THE
NEAR TERM...LIGHT RAINS FALLING FROM RELATIVELY HIGH ALTOCUMULUS
MAY PRODUCE A PERIOD OF VERY LIGHT RAINS AROUND SAVANNAH THROUGH
MID EVENING AND PERHAPS LATER THIS EVENING AT KCHS. LATE TONIGHT
THERE COULD BE ADVECTION STRATUS IN WARM AIR ADVECTION AHEAD OF A
COLD FRONT. MVFR TO OCCASIONAL IFR CIGS ARE LIKELY ON FRIDAY AFTER
MID MORNING AS SHOWERS MOVE INTO THE COASTAL CORRIDOR. LATER IN
THE DAY SOME ENHANCED DRYING BEHIND THE FRONT COULD RESULT IN VFR
CONDITIONS AT KSAV WITH GUSTY WEST WINDS. AT KCHS...HIGH MOISTURE
CONTENT IN THE 1000-850 MB LAYER LIKELY TO KEEP LOWER CLOUDS MORE
RESILIENT TO SHIFTING WINDS IN THE LOWER LEVELS.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
OVERNIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF
AN APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND
GUSTS AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WERE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.
SEA FOG IS STILL PREVALENT AS PER GOES-E SATELLITE IMAGERY AND
COASTAL OBSERVATIONS. SOME OF THE FOG WILL BE LOCALLY DENSE...BUT
INCREASING WINDS WILL LIKELY PREVENT IT FROM BECOMING TOO
WIDESPREAD AND THUS NO DENSE FOG ADVISORY AT THIS TIME.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 1 PM EDT
     SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM EDT
     THIS AFTERNOON FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...





000
FXUS62 KCHS 270449
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1249 AM EDT FRI MAR 27 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WE ADJUSTED POPS SLIGHTLY TO ACCOUNT FOR THE SHORT WAVE PUSHING
THROUGH THE NEARBY ATLANTIC FROM SW TO NE OVERNIGHT. THE BULK OF
THE ACTIVITY WILL STAY OFFSHORE...BUT WE HAVE SLIGHT CHANCE AND
CHANCES POPS AS A RESULT...HIGHEST ON THE SC COAST.

TEMPS SHOULD BE LINGERING IN THE 60S OVERNIGHT WITH DEW POINTS
REMAINING ELEVATED IN THE LOWER 60S MOST AREAS. LOW LEVEL WIND
FIELDS SHOULD INCREASE OVERNIGHT WHICH DO NOT FAVOR FOG HOWEVER
THE RICH LOW LEVEL MOISTURE CONTENT MAY RESULT IN SOME FORM OF
ADVECTION STRATUS FROM THE GULF OR ATLC OVERNIGHT...PLUS NEARBY
SEA FOG OVER THE ATLANTIC WILL SKIRT COASTAL SECTIONS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH THE EVENING...WITH INCREASING CHANCES FOR MVFR/IFR
CIGS LATER TONIGHT...ESPECIALLY CLOSING IN ON DAYBREAK. IN THE
NEAR TERM...LIGHT RAINS FALLING FROM RELATIVELY HIGH ALTOCUMULUS
MAY PRODUCE A PERIOD OF VERY LIGHT RAINS AROUND SAVANNAH THROUGH
MID EVENING AND PERHAPS LATER THIS EVENING AT KCHS. LATE TONIGHT
THERE COULD BE ADVECTION STRATUS IN WARM AIR ADVECTION AHEAD OF A
COLD FRONT. MVFR TO OCCASIONAL IFR CIGS ARE LIKELY ON FRIDAY AFTER
MID MORNING AS SHOWERS MOVE INTO THE COASTAL CORRIDOR. LATER IN
THE DAY SOME ENHANCED DRYING BEHIND THE FRONT COULD RESULT IN VFR
CONDITIONS AT KSAV WITH GUSTY WEST WINDS. AT KCHS...HIGH MOISTURE
CONTENT IN THE 1000-850 MB LAYER LIKELY TO KEEP LOWER CLOUDS MORE
RESILIENT TO SHIFTING WINDS IN THE LOWER LEVELS.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
OVERNIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF
AN APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND
GUSTS AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WERE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.
SEA FOG IS STILL PREVALENT AS PER GOES-E SATELLITE IMAGERY AND
COASTAL OBSERVATIONS. SOME OF THE FOG WILL BE LOCALLY DENSE...BUT
INCREASING WINDS WILL LIKELY PREVENT IT FROM BECOMING TOO
WIDESPREAD AND THUS NO DENSE FOG ADVISORY AT THIS TIME.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 1 PM EDT
     SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM EDT
     THIS AFTERNOON FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS62 KCHS 270142
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
942 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A MID LEVEL SHORT WAVE LIFTING NE FROM THE SE GULF COAST REGION
THIS AFTERNOON WAS SLIDING THROUGH SE GEORGIA THIS EVENING AND
WILL MOVE OFFSHORE OVERNIGHT. LIGHT RAINS FALLING FROM A THICKER
MID DECK WERE DWINDLING AS THEY PASS OVER THE FORECAST AREA. THE
00Z KCHS SOUNDING INDICATED SOME DEEP LAYERS OF DRY AIR IN THE
SUB-CLOUD REGION WHICH WERE TENDING TO DIMINISH PCPN AS IT
EVAPORATES ON THE WAY DOWN. WE HAVE MADE SOME SIGNIFICANT CHANGES
LATER TONIGHT AS PRE-FRONTAL RAINS APPEAR TO STILL BE MAINLY OFF
TO THE WEST AT DAYBREAK. WE MAINTAINED 20-30 POPS OVERNIGHT WITH
NOT MUCH PROSPECT OF ANY SIGNIFICANT RAINS ANYWHERE. TEMPS SHOULD
BE LINGERING IN THE 60S OVERNIGHT WITH DEW POINTS REMAINING
ELEVATED IN THE LOWER 60S MOST AREAS. LOW LEVEL WIND FIELDS SHOULD
INCREASE OVERNIGHT WHICH DO NOT FAVOR FOG HOWEVER THE RICH LOW
LEVEL MOISTURE CONTENT MAY RESULT IN SOME FORM OF ADVECTION
STRATUS FROM THE GULF OR ATLC OVERNIGHT.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH THE EVENING...WITH INCREASING CHANCES FOR MVFR/IFR
CIGS LATER TONIGHT...ESPECIALLY CLOSING IN ON DAYBREAK. IN THE
NEAR TERM...LIGHT RAINS FALLING FROM RELATIVELY HIGH ALTOCUMULUS
MAY PRODUCE A PERIOD OF VERY LIGHT RAINS AROUND SAVANNAH THROUGH
MID EVENING AND PERHAPS LATER THIS EVENING AT KCHS. LATE TONIGHT
THERE COULD BE ADVECTION STRATUS IN WARM AIR ADVECTION AHEAD OF A
COLD FRONT. MVFR TO OCCASIONAL IFR CIGS ARE LIKELY ON FRIDAY AFTER
MID MORNING AS SHOWERS MOVE INTO THE COASTAL CORRIDOR. LATER IN
THE DAY SOME ENHANCED DRYING BEHIND THE FRONT COULD RESULT IN VFR
CONDITIONS AT KSAV WITH GUSTY WEST WINDS. AT KCHS...HIGH MOISTURE
CONTENT IN THE 1000-850 MB LAYER LIKELY TO KEEP LOWER CLOUDS MORE
RESILIENT TO SHIFTING WINDS IN THE LOWER LEVELS.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
WE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 6 PM PER DISCUSSIONS
WITH BOTH THE CHARLESTON AND SAVANNAH PILOT DISPATCH OFFICES. THE
RISK FOR AT LEAST PATCHY DENSE FOG WILL LINGER THROUGH THE NIGHT
AS WINDS EVENTUALLY VEER AHEAD OF THE COLD FRONT.

OVERNIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF
AN APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND
GUSTS AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WERE RAISED
FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST PACKAGE.
WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING MARINE ZONES
WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS62 KCHS 270142
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
942 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A MID LEVEL SHORT WAVE LIFTING NE FROM THE SE GULF COAST REGION
THIS AFTERNOON WAS SLIDING THROUGH SE GEORGIA THIS EVENING AND
WILL MOVE OFFSHORE OVERNIGHT. LIGHT RAINS FALLING FROM A THICKER
MID DECK WERE DWINDLING AS THEY PASS OVER THE FORECAST AREA. THE
00Z KCHS SOUNDING INDICATED SOME DEEP LAYERS OF DRY AIR IN THE
SUB-CLOUD REGION WHICH WERE TENDING TO DIMINISH PCPN AS IT
EVAPORATES ON THE WAY DOWN. WE HAVE MADE SOME SIGNIFICANT CHANGES
LATER TONIGHT AS PRE-FRONTAL RAINS APPEAR TO STILL BE MAINLY OFF
TO THE WEST AT DAYBREAK. WE MAINTAINED 20-30 POPS OVERNIGHT WITH
NOT MUCH PROSPECT OF ANY SIGNIFICANT RAINS ANYWHERE. TEMPS SHOULD
BE LINGERING IN THE 60S OVERNIGHT WITH DEW POINTS REMAINING
ELEVATED IN THE LOWER 60S MOST AREAS. LOW LEVEL WIND FIELDS SHOULD
INCREASE OVERNIGHT WHICH DO NOT FAVOR FOG HOWEVER THE RICH LOW
LEVEL MOISTURE CONTENT MAY RESULT IN SOME FORM OF ADVECTION
STRATUS FROM THE GULF OR ATLC OVERNIGHT.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH THE EVENING...WITH INCREASING CHANCES FOR MVFR/IFR
CIGS LATER TONIGHT...ESPECIALLY CLOSING IN ON DAYBREAK. IN THE
NEAR TERM...LIGHT RAINS FALLING FROM RELATIVELY HIGH ALTOCUMULUS
MAY PRODUCE A PERIOD OF VERY LIGHT RAINS AROUND SAVANNAH THROUGH
MID EVENING AND PERHAPS LATER THIS EVENING AT KCHS. LATE TONIGHT
THERE COULD BE ADVECTION STRATUS IN WARM AIR ADVECTION AHEAD OF A
COLD FRONT. MVFR TO OCCASIONAL IFR CIGS ARE LIKELY ON FRIDAY AFTER
MID MORNING AS SHOWERS MOVE INTO THE COASTAL CORRIDOR. LATER IN
THE DAY SOME ENHANCED DRYING BEHIND THE FRONT COULD RESULT IN VFR
CONDITIONS AT KSAV WITH GUSTY WEST WINDS. AT KCHS...HIGH MOISTURE
CONTENT IN THE 1000-850 MB LAYER LIKELY TO KEEP LOWER CLOUDS MORE
RESILIENT TO SHIFTING WINDS IN THE LOWER LEVELS.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
WE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 6 PM PER DISCUSSIONS
WITH BOTH THE CHARLESTON AND SAVANNAH PILOT DISPATCH OFFICES. THE
RISK FOR AT LEAST PATCHY DENSE FOG WILL LINGER THROUGH THE NIGHT
AS WINDS EVENTUALLY VEER AHEAD OF THE COLD FRONT.

OVERNIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF
AN APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND
GUSTS AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WERE RAISED
FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST PACKAGE.
WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING MARINE ZONES
WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...





000
FXUS62 KCHS 262341
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
741 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
ON THE EARLY EVENING UPDATE...INITIALIZATION ADJUSTMENTS TO
TEMPS...DEW POINTS...AND SKY COVER. THE REMAINDER OF THE FORECAST
ON TRACK AS AN AREA OF LIGHT RAINS MOVE INTO SE GEORGIA...AMOUNTS
EXPECTED TO BE QUITE LIGHT AS EVAPORATIVE PROCESSES TAKING PLACE
IN A DRIER DEEP LAYER BELOW THE PRECIPITATING HIGHER CLOUD DECKS.

THE AREA WILL REMAIN WELL WITHIN THE WARM SECTOR TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. FAVORABLE UVM INDUCED BY THE RIGHT
ENTRANCE REGION OF A DEPARTING 250 HPA JET STREAK COUPLED WITH A
850 HPA 30-35 KT LOW-LEVEL JET AND RIBBON OF PWATS APPROACHING
1.50 INCHES WILL SUPPORT SOME SHOWER ACTIVITY OVERNIGHT...HOWEVER
IT REMAINS UNCLEAR EXACTLY HOW WIDESPREAD THIS ACTIVITY WILL
BECOME AS EXTENSIVE CONVECTION ALONG THE GULF COAST IS FORECAST TO
PERSIST THROUGH THE NIGHT.

WE CONTINUE TO MAINTAIN FAIRLY LOW POPS FOR TONIGHT ESPECIALLY
DURING THE EVENING HOURS WHERE LITTLE SIGNIFICANT SHOWER ACTIVITY
IS EXPECTED...OUTSIDE OF SOME PATCHY LIGHT RAINS AND A FEW
SHOWERS WAS BLEEDING INTO THE AREA FROM THE SOUTHWEST PER LATEST
KTLH/KVAX RADAR TRENDS. STILL EXPECT SCATTERED TO PERHAPS NUMEROUS
SHOWERS TO BREAK OUT JUST BEFORE SUNRISE AS THE COLD FRONT DRAWS
CLOSER AND LOW-LEVEL CONVERGENCE INCREASES...BUT EVEN THIS MAY
PROVE TO BE TOO QUICK IF MODELS CONTINUE TO TREND SLOWER WITH THE
PROGRESSION OF THE COLD FRONT. MAXIMUM POPS WILL RANGE FROM 40-50
PERCENT AT THE COAST WITH 50-60 PERCENT INLAND. LOWS WILL ONLY
BOTTOM OUT IN THE LOWER 60S WITH A FEW UPPER 50S ALONG THE
BEACHES.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE EVENING...WITH INCREASING CHANCES FOR MVFR/IFR
CIGS LATER TONIGHT...ESPECIALLY CLOSING IN ON DAYBREAK. IN THE
NEAR TERM...LIGHT RAINS FALLING FROM RELATIVELY HIGH ALTOCUMULUS
MAY PRODUCE A PERIOD OF VERY LIGHT RAINS AROUND SAVANNAH THROUGH
MID EVENING AND PERHAPS LATER THIS EVENING AT KCHS. LATE TONIGHT
THERE COULD BE ADVECTION STRATUS IN WARM AIR ADVECTION AHEAD OF A
COLD FRONT. MVFR TO OCCASIONAL IFR CIGS ARE LIKELY ON FRIDAY AFTER
MID MORNING AS SHOWERS MOVE INTO THE COASTAL CORRIDOR. LATER IN
THE DAY SOME ENHANCED DRYING BEHIND THE FRONT COULD RESULT IN VFR
CONDITIONS AT KSAV WITH GUSTY WEST WINDS. AT KCHS...HIGH MOISTURE
CONTENT IN THE 1000-850 MB LAYER LIKELY TO KEEP LOWER CLOUDS MORE
RESILIENT TO SHIFTING WINDS IN THE LOWER LEVELS.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
WE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 6 PM PER DISCUSSIONS
WITH BOTH THE CHARLESTON AND SAVANNAH PILOT DISPATCH OFFICES. THE
RISK FOR AT LEAST PATCHY DENSE FOG WILL LINGER THROUGH THE NIGHT
AS WINDS EVENTUALLY VEER AHEAD OF THE COLD FRONT.

TONIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF AN
APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND GUSTS
AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WILL BE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS62 KCHS 262341
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
741 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
ON THE EARLY EVENING UPDATE...INITIALIZATION ADJUSTMENTS TO
TEMPS...DEW POINTS...AND SKY COVER. THE REMAINDER OF THE FORECAST
ON TRACK AS AN AREA OF LIGHT RAINS MOVE INTO SE GEORGIA...AMOUNTS
EXPECTED TO BE QUITE LIGHT AS EVAPORATIVE PROCESSES TAKING PLACE
IN A DRIER DEEP LAYER BELOW THE PRECIPITATING HIGHER CLOUD DECKS.

THE AREA WILL REMAIN WELL WITHIN THE WARM SECTOR TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. FAVORABLE UVM INDUCED BY THE RIGHT
ENTRANCE REGION OF A DEPARTING 250 HPA JET STREAK COUPLED WITH A
850 HPA 30-35 KT LOW-LEVEL JET AND RIBBON OF PWATS APPROACHING
1.50 INCHES WILL SUPPORT SOME SHOWER ACTIVITY OVERNIGHT...HOWEVER
IT REMAINS UNCLEAR EXACTLY HOW WIDESPREAD THIS ACTIVITY WILL
BECOME AS EXTENSIVE CONVECTION ALONG THE GULF COAST IS FORECAST TO
PERSIST THROUGH THE NIGHT.

WE CONTINUE TO MAINTAIN FAIRLY LOW POPS FOR TONIGHT ESPECIALLY
DURING THE EVENING HOURS WHERE LITTLE SIGNIFICANT SHOWER ACTIVITY
IS EXPECTED...OUTSIDE OF SOME PATCHY LIGHT RAINS AND A FEW
SHOWERS WAS BLEEDING INTO THE AREA FROM THE SOUTHWEST PER LATEST
KTLH/KVAX RADAR TRENDS. STILL EXPECT SCATTERED TO PERHAPS NUMEROUS
SHOWERS TO BREAK OUT JUST BEFORE SUNRISE AS THE COLD FRONT DRAWS
CLOSER AND LOW-LEVEL CONVERGENCE INCREASES...BUT EVEN THIS MAY
PROVE TO BE TOO QUICK IF MODELS CONTINUE TO TREND SLOWER WITH THE
PROGRESSION OF THE COLD FRONT. MAXIMUM POPS WILL RANGE FROM 40-50
PERCENT AT THE COAST WITH 50-60 PERCENT INLAND. LOWS WILL ONLY
BOTTOM OUT IN THE LOWER 60S WITH A FEW UPPER 50S ALONG THE
BEACHES.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE EVENING...WITH INCREASING CHANCES FOR MVFR/IFR
CIGS LATER TONIGHT...ESPECIALLY CLOSING IN ON DAYBREAK. IN THE
NEAR TERM...LIGHT RAINS FALLING FROM RELATIVELY HIGH ALTOCUMULUS
MAY PRODUCE A PERIOD OF VERY LIGHT RAINS AROUND SAVANNAH THROUGH
MID EVENING AND PERHAPS LATER THIS EVENING AT KCHS. LATE TONIGHT
THERE COULD BE ADVECTION STRATUS IN WARM AIR ADVECTION AHEAD OF A
COLD FRONT. MVFR TO OCCASIONAL IFR CIGS ARE LIKELY ON FRIDAY AFTER
MID MORNING AS SHOWERS MOVE INTO THE COASTAL CORRIDOR. LATER IN
THE DAY SOME ENHANCED DRYING BEHIND THE FRONT COULD RESULT IN VFR
CONDITIONS AT KSAV WITH GUSTY WEST WINDS. AT KCHS...HIGH MOISTURE
CONTENT IN THE 1000-850 MB LAYER LIKELY TO KEEP LOWER CLOUDS MORE
RESILIENT TO SHIFTING WINDS IN THE LOWER LEVELS.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
WE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 6 PM PER DISCUSSIONS
WITH BOTH THE CHARLESTON AND SAVANNAH PILOT DISPATCH OFFICES. THE
RISK FOR AT LEAST PATCHY DENSE FOG WILL LINGER THROUGH THE NIGHT
AS WINDS EVENTUALLY VEER AHEAD OF THE COLD FRONT.

TONIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF AN
APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND GUSTS
AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WILL BE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS62 KCHS 262341
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
741 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
ON THE EARLY EVENING UPDATE...INITIALIZATION ADJUSTMENTS TO
TEMPS...DEW POINTS...AND SKY COVER. THE REMAINDER OF THE FORECAST
ON TRACK AS AN AREA OF LIGHT RAINS MOVE INTO SE GEORGIA...AMOUNTS
EXPECTED TO BE QUITE LIGHT AS EVAPORATIVE PROCESSES TAKING PLACE
IN A DRIER DEEP LAYER BELOW THE PRECIPITATING HIGHER CLOUD DECKS.

THE AREA WILL REMAIN WELL WITHIN THE WARM SECTOR TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. FAVORABLE UVM INDUCED BY THE RIGHT
ENTRANCE REGION OF A DEPARTING 250 HPA JET STREAK COUPLED WITH A
850 HPA 30-35 KT LOW-LEVEL JET AND RIBBON OF PWATS APPROACHING
1.50 INCHES WILL SUPPORT SOME SHOWER ACTIVITY OVERNIGHT...HOWEVER
IT REMAINS UNCLEAR EXACTLY HOW WIDESPREAD THIS ACTIVITY WILL
BECOME AS EXTENSIVE CONVECTION ALONG THE GULF COAST IS FORECAST TO
PERSIST THROUGH THE NIGHT.

WE CONTINUE TO MAINTAIN FAIRLY LOW POPS FOR TONIGHT ESPECIALLY
DURING THE EVENING HOURS WHERE LITTLE SIGNIFICANT SHOWER ACTIVITY
IS EXPECTED...OUTSIDE OF SOME PATCHY LIGHT RAINS AND A FEW
SHOWERS WAS BLEEDING INTO THE AREA FROM THE SOUTHWEST PER LATEST
KTLH/KVAX RADAR TRENDS. STILL EXPECT SCATTERED TO PERHAPS NUMEROUS
SHOWERS TO BREAK OUT JUST BEFORE SUNRISE AS THE COLD FRONT DRAWS
CLOSER AND LOW-LEVEL CONVERGENCE INCREASES...BUT EVEN THIS MAY
PROVE TO BE TOO QUICK IF MODELS CONTINUE TO TREND SLOWER WITH THE
PROGRESSION OF THE COLD FRONT. MAXIMUM POPS WILL RANGE FROM 40-50
PERCENT AT THE COAST WITH 50-60 PERCENT INLAND. LOWS WILL ONLY
BOTTOM OUT IN THE LOWER 60S WITH A FEW UPPER 50S ALONG THE
BEACHES.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE EVENING...WITH INCREASING CHANCES FOR MVFR/IFR
CIGS LATER TONIGHT...ESPECIALLY CLOSING IN ON DAYBREAK. IN THE
NEAR TERM...LIGHT RAINS FALLING FROM RELATIVELY HIGH ALTOCUMULUS
MAY PRODUCE A PERIOD OF VERY LIGHT RAINS AROUND SAVANNAH THROUGH
MID EVENING AND PERHAPS LATER THIS EVENING AT KCHS. LATE TONIGHT
THERE COULD BE ADVECTION STRATUS IN WARM AIR ADVECTION AHEAD OF A
COLD FRONT. MVFR TO OCCASIONAL IFR CIGS ARE LIKELY ON FRIDAY AFTER
MID MORNING AS SHOWERS MOVE INTO THE COASTAL CORRIDOR. LATER IN
THE DAY SOME ENHANCED DRYING BEHIND THE FRONT COULD RESULT IN VFR
CONDITIONS AT KSAV WITH GUSTY WEST WINDS. AT KCHS...HIGH MOISTURE
CONTENT IN THE 1000-850 MB LAYER LIKELY TO KEEP LOWER CLOUDS MORE
RESILIENT TO SHIFTING WINDS IN THE LOWER LEVELS.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
WE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 6 PM PER DISCUSSIONS
WITH BOTH THE CHARLESTON AND SAVANNAH PILOT DISPATCH OFFICES. THE
RISK FOR AT LEAST PATCHY DENSE FOG WILL LINGER THROUGH THE NIGHT
AS WINDS EVENTUALLY VEER AHEAD OF THE COLD FRONT.

TONIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF AN
APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND GUSTS
AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WILL BE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...





000
FXUS62 KCHS 262341
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
741 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
ON THE EARLY EVENING UPDATE...INITIALIZATION ADJUSTMENTS TO
TEMPS...DEW POINTS...AND SKY COVER. THE REMAINDER OF THE FORECAST
ON TRACK AS AN AREA OF LIGHT RAINS MOVE INTO SE GEORGIA...AMOUNTS
EXPECTED TO BE QUITE LIGHT AS EVAPORATIVE PROCESSES TAKING PLACE
IN A DRIER DEEP LAYER BELOW THE PRECIPITATING HIGHER CLOUD DECKS.

THE AREA WILL REMAIN WELL WITHIN THE WARM SECTOR TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. FAVORABLE UVM INDUCED BY THE RIGHT
ENTRANCE REGION OF A DEPARTING 250 HPA JET STREAK COUPLED WITH A
850 HPA 30-35 KT LOW-LEVEL JET AND RIBBON OF PWATS APPROACHING
1.50 INCHES WILL SUPPORT SOME SHOWER ACTIVITY OVERNIGHT...HOWEVER
IT REMAINS UNCLEAR EXACTLY HOW WIDESPREAD THIS ACTIVITY WILL
BECOME AS EXTENSIVE CONVECTION ALONG THE GULF COAST IS FORECAST TO
PERSIST THROUGH THE NIGHT.

WE CONTINUE TO MAINTAIN FAIRLY LOW POPS FOR TONIGHT ESPECIALLY
DURING THE EVENING HOURS WHERE LITTLE SIGNIFICANT SHOWER ACTIVITY
IS EXPECTED...OUTSIDE OF SOME PATCHY LIGHT RAINS AND A FEW
SHOWERS WAS BLEEDING INTO THE AREA FROM THE SOUTHWEST PER LATEST
KTLH/KVAX RADAR TRENDS. STILL EXPECT SCATTERED TO PERHAPS NUMEROUS
SHOWERS TO BREAK OUT JUST BEFORE SUNRISE AS THE COLD FRONT DRAWS
CLOSER AND LOW-LEVEL CONVERGENCE INCREASES...BUT EVEN THIS MAY
PROVE TO BE TOO QUICK IF MODELS CONTINUE TO TREND SLOWER WITH THE
PROGRESSION OF THE COLD FRONT. MAXIMUM POPS WILL RANGE FROM 40-50
PERCENT AT THE COAST WITH 50-60 PERCENT INLAND. LOWS WILL ONLY
BOTTOM OUT IN THE LOWER 60S WITH A FEW UPPER 50S ALONG THE
BEACHES.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE EVENING...WITH INCREASING CHANCES FOR MVFR/IFR
CIGS LATER TONIGHT...ESPECIALLY CLOSING IN ON DAYBREAK. IN THE
NEAR TERM...LIGHT RAINS FALLING FROM RELATIVELY HIGH ALTOCUMULUS
MAY PRODUCE A PERIOD OF VERY LIGHT RAINS AROUND SAVANNAH THROUGH
MID EVENING AND PERHAPS LATER THIS EVENING AT KCHS. LATE TONIGHT
THERE COULD BE ADVECTION STRATUS IN WARM AIR ADVECTION AHEAD OF A
COLD FRONT. MVFR TO OCCASIONAL IFR CIGS ARE LIKELY ON FRIDAY AFTER
MID MORNING AS SHOWERS MOVE INTO THE COASTAL CORRIDOR. LATER IN
THE DAY SOME ENHANCED DRYING BEHIND THE FRONT COULD RESULT IN VFR
CONDITIONS AT KSAV WITH GUSTY WEST WINDS. AT KCHS...HIGH MOISTURE
CONTENT IN THE 1000-850 MB LAYER LIKELY TO KEEP LOWER CLOUDS MORE
RESILIENT TO SHIFTING WINDS IN THE LOWER LEVELS.

EXTENDED AVIATION OUTLOOK...VFR WEATHER WILL PREVAIL FRIDAY NIGHT
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
WE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 6 PM PER DISCUSSIONS
WITH BOTH THE CHARLESTON AND SAVANNAH PILOT DISPATCH OFFICES. THE
RISK FOR AT LEAST PATCHY DENSE FOG WILL LINGER THROUGH THE NIGHT
AS WINDS EVENTUALLY VEER AHEAD OF THE COLD FRONT.

TONIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF AN
APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND GUSTS
AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WILL BE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...





000
FXUS62 KCHS 262015
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
415 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE AREA WILL REMAIN WELL WITHIN THE WARM SECTOR TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. FAVORABLE UVM INDUCED BY THE RIGHT
ENTRANCE REGION OF A DEPARTING 250 HPA JET STREAK COUPLED WITH A
850 HPA 30-35 KT LOW-LEVEL JET AND RIBBON OF PWATS APPROACHING
1.50 INCHES WILL SUPPORT SOME SHOWER ACTIVITY OVERNIGHT...HOWEVER
IT IS UNCLEAR EXACTLY HOW WIDESPREAD THIS ACTIVITY WILL BECOME AS
EXTENSIVE CONVECTION ALONG THE GULF COAST IS FORECAST TO PERSIST
THROUGH THE NIGHT. THIS AREA OF CONVECTION WILL TEND TO DISRUPT
THE NECESSARY LOW-LEVEL INFLOW OF GULF MOISTURE INTO THE REGION
AHEAD OF THE FRONT...WHICH IS ALWAYS A PROBLEMATIC ELEMENT WHEN
FORECASTING PRECIPITATION FOR THE LOWCOUNTRY AND COASTAL EMPIRE.
BOTH THE 26/12Z GFS AND NAM WITH SUPPORT FROM THE LATEST SREF HAVE
PICKED UP ON THIS AND HAVE TRENDED DRIER FOR MUCH OF THE OVERNIGHT
PERIOD.

WILL LOWER POPS FOR TONIGHT ESPECIALLY DURING THE EVENING HOURS
WHERE LITTLE SIGNIFICANT SHOWER ACTIVITY IS EXPECTED...OUTSIDE OF
A FEW SHOWERS WHICH MAY BLEED INTO THE AREA FROM THE SOUTHWEST
PER LATEST KTLH/KVAX RADAR TRENDS. STILL EXPECT SCATTERED TO
PERHAPS NUMEROUS SHOWERS TO BREAK OUT JUST BEFORE SUNRISE AS THE
COLD FRONT DRAWS CLOSER AND LOW- LEVEL CONVERGENCE INCREASES...BUT
EVEN THIS MAY PROVE TO BE TOO QUICK IF MODELS CONTINUE TO TREND
SLOWER WITH THE PROGRESSION OF THE COLD FRONT. MAXIMUM POPS WILL
RANGE FROM 40-50 PERCENT AT THE COAST WITH 50-60 PERCENT INLAND.
LOWS WILL ONLY BOTTOM OUT IN THE LOWER 60S WITH A FEW UPPER 50S
ALONG THE BEACHES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE AFTERNOON INTO THIS EVENING...WITH INCREASING
CHANCES FOR MVFR CIGS AND RAIN SHOWERS AFTER 06Z. THE BULK OF THE
HEAVIEST RAINS WILL LIKELY HOLD OFF UNTIL CLOSER TO SUNRISE
FRIDAY...ALTHOUGH SOME GUIDANCE SUGGESTS EVEN LATER THAN THAT.
WILL INCLUDE PREVAILING 5SM -SHRA FROM 10Z ON AT BOTH TERMINALS.
WILL ALSO INCLUDE A TEMPO FOR BRIEF SHOWERS AT KSAV FROM ROUGHLY
23-01Z AS HIGH RESOLUTION DATA SUPPORT SHOWERS IN THAT AREA ALONG
THE SEA BREEZE.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA...AS A COLD FRONT
MOVES THROUGH THE AREA. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
SEA FOG...TRICKY SEA FOG FORECAST THROUGH THIS EVENING. LOW-LEVEL
WINDS HAVE TURNED A BIT MORE SOUTHEAST ALONG THE GEORGIA COAST
WHICH IS DIMINISHING PARCEL RESIDENCE TIMES ACROSS THE CORE OF THE
COLDER SHELF WATERS. THIS HAS RESULTED IN AN IMPROVEMENT IN VSBYS
ACROSS BOTH GEORGIA MARINE ZONES. FARTHER NORTH...SOUTHWEST WINDS
HAVE NOT SHOWN ANY INDICATION OF BACKING WITH THE SEA BREEZE...SO
WIDESPREAD DENSE SEA FOG LINGERS. HIGH RESOLUTION MODELS SUGGEST
MOST OF THE FOG ALONG THE LOWER SOUTH CAROLINA COASTAL WATER...OR
AT LEAST A GOOD PORTION OF IT...WILL LIKELY LIFT OR THIN OUT AS
WINDS EVENTUALLY BACK WITH THE STRENGTHENING SEA BREEZE
CIRCULATION. THIS TREND IS SUPPORTED BY BOTH THE RAP AND H3R VSBY
PROGS WHICH HAVE DONE QUITE WELL SO FAR TODAY.

WILL TAKE THE DENSE FOG ADVISORY UNTIL 6 PM FOR THE SOUTH
CAROLINA COASTAL MARINE ZONES...BUT CANCEL IT FOR THE GEORGIA
MARINE ZONES. ATTM IT APPEARS THERE WILL BE ENOUGH MIXING AROUND
CHARLESTON HARBOR FOR THE FOG TO MAKE TOO MUCH PROGRESS INTO THE
MAIN HARBOR ITSELF...BUT WILL MORE LIKELY REMAIN JUST AT THE
HARBOR ENTRANCE AROUND FORT SUMTER. WILL NOT ISSUE A DENSE FOG
ADVISORY FOR THE HARBOR ATTM. THE RISK FOR AT LEAST PATCHY FOG
WILL LINGER THROUGH THE NIGHT AS WINDS EVENTUALLY VEER AHEAD OF
THE COLD FRONT.

TONIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF AN
APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND GUSTS
AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WILL BE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR AMZ350-352.
     SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$

ST/WMS





000
FXUS62 KCHS 262015
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
415 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE AREA WILL REMAIN WELL WITHIN THE WARM SECTOR TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. FAVORABLE UVM INDUCED BY THE RIGHT
ENTRANCE REGION OF A DEPARTING 250 HPA JET STREAK COUPLED WITH A
850 HPA 30-35 KT LOW-LEVEL JET AND RIBBON OF PWATS APPROACHING
1.50 INCHES WILL SUPPORT SOME SHOWER ACTIVITY OVERNIGHT...HOWEVER
IT IS UNCLEAR EXACTLY HOW WIDESPREAD THIS ACTIVITY WILL BECOME AS
EXTENSIVE CONVECTION ALONG THE GULF COAST IS FORECAST TO PERSIST
THROUGH THE NIGHT. THIS AREA OF CONVECTION WILL TEND TO DISRUPT
THE NECESSARY LOW-LEVEL INFLOW OF GULF MOISTURE INTO THE REGION
AHEAD OF THE FRONT...WHICH IS ALWAYS A PROBLEMATIC ELEMENT WHEN
FORECASTING PRECIPITATION FOR THE LOWCOUNTRY AND COASTAL EMPIRE.
BOTH THE 26/12Z GFS AND NAM WITH SUPPORT FROM THE LATEST SREF HAVE
PICKED UP ON THIS AND HAVE TRENDED DRIER FOR MUCH OF THE OVERNIGHT
PERIOD.

WILL LOWER POPS FOR TONIGHT ESPECIALLY DURING THE EVENING HOURS
WHERE LITTLE SIGNIFICANT SHOWER ACTIVITY IS EXPECTED...OUTSIDE OF
A FEW SHOWERS WHICH MAY BLEED INTO THE AREA FROM THE SOUTHWEST
PER LATEST KTLH/KVAX RADAR TRENDS. STILL EXPECT SCATTERED TO
PERHAPS NUMEROUS SHOWERS TO BREAK OUT JUST BEFORE SUNRISE AS THE
COLD FRONT DRAWS CLOSER AND LOW- LEVEL CONVERGENCE INCREASES...BUT
EVEN THIS MAY PROVE TO BE TOO QUICK IF MODELS CONTINUE TO TREND
SLOWER WITH THE PROGRESSION OF THE COLD FRONT. MAXIMUM POPS WILL
RANGE FROM 40-50 PERCENT AT THE COAST WITH 50-60 PERCENT INLAND.
LOWS WILL ONLY BOTTOM OUT IN THE LOWER 60S WITH A FEW UPPER 50S
ALONG THE BEACHES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE AFTERNOON INTO THIS EVENING...WITH INCREASING
CHANCES FOR MVFR CIGS AND RAIN SHOWERS AFTER 06Z. THE BULK OF THE
HEAVIEST RAINS WILL LIKELY HOLD OFF UNTIL CLOSER TO SUNRISE
FRIDAY...ALTHOUGH SOME GUIDANCE SUGGESTS EVEN LATER THAN THAT.
WILL INCLUDE PREVAILING 5SM -SHRA FROM 10Z ON AT BOTH TERMINALS.
WILL ALSO INCLUDE A TEMPO FOR BRIEF SHOWERS AT KSAV FROM ROUGHLY
23-01Z AS HIGH RESOLUTION DATA SUPPORT SHOWERS IN THAT AREA ALONG
THE SEA BREEZE.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA...AS A COLD FRONT
MOVES THROUGH THE AREA. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
SEA FOG...TRICKY SEA FOG FORECAST THROUGH THIS EVENING. LOW-LEVEL
WINDS HAVE TURNED A BIT MORE SOUTHEAST ALONG THE GEORGIA COAST
WHICH IS DIMINISHING PARCEL RESIDENCE TIMES ACROSS THE CORE OF THE
COLDER SHELF WATERS. THIS HAS RESULTED IN AN IMPROVEMENT IN VSBYS
ACROSS BOTH GEORGIA MARINE ZONES. FARTHER NORTH...SOUTHWEST WINDS
HAVE NOT SHOWN ANY INDICATION OF BACKING WITH THE SEA BREEZE...SO
WIDESPREAD DENSE SEA FOG LINGERS. HIGH RESOLUTION MODELS SUGGEST
MOST OF THE FOG ALONG THE LOWER SOUTH CAROLINA COASTAL WATER...OR
AT LEAST A GOOD PORTION OF IT...WILL LIKELY LIFT OR THIN OUT AS
WINDS EVENTUALLY BACK WITH THE STRENGTHENING SEA BREEZE
CIRCULATION. THIS TREND IS SUPPORTED BY BOTH THE RAP AND H3R VSBY
PROGS WHICH HAVE DONE QUITE WELL SO FAR TODAY.

WILL TAKE THE DENSE FOG ADVISORY UNTIL 6 PM FOR THE SOUTH
CAROLINA COASTAL MARINE ZONES...BUT CANCEL IT FOR THE GEORGIA
MARINE ZONES. ATTM IT APPEARS THERE WILL BE ENOUGH MIXING AROUND
CHARLESTON HARBOR FOR THE FOG TO MAKE TOO MUCH PROGRESS INTO THE
MAIN HARBOR ITSELF...BUT WILL MORE LIKELY REMAIN JUST AT THE
HARBOR ENTRANCE AROUND FORT SUMTER. WILL NOT ISSUE A DENSE FOG
ADVISORY FOR THE HARBOR ATTM. THE RISK FOR AT LEAST PATCHY FOG
WILL LINGER THROUGH THE NIGHT AS WINDS EVENTUALLY VEER AHEAD OF
THE COLD FRONT.

TONIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF AN
APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND GUSTS
AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WILL BE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR AMZ350-352.
     SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$

ST/WMS




000
FXUS62 KCHS 262015
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
415 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE AREA WILL REMAIN WELL WITHIN THE WARM SECTOR TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. FAVORABLE UVM INDUCED BY THE RIGHT
ENTRANCE REGION OF A DEPARTING 250 HPA JET STREAK COUPLED WITH A
850 HPA 30-35 KT LOW-LEVEL JET AND RIBBON OF PWATS APPROACHING
1.50 INCHES WILL SUPPORT SOME SHOWER ACTIVITY OVERNIGHT...HOWEVER
IT IS UNCLEAR EXACTLY HOW WIDESPREAD THIS ACTIVITY WILL BECOME AS
EXTENSIVE CONVECTION ALONG THE GULF COAST IS FORECAST TO PERSIST
THROUGH THE NIGHT. THIS AREA OF CONVECTION WILL TEND TO DISRUPT
THE NECESSARY LOW-LEVEL INFLOW OF GULF MOISTURE INTO THE REGION
AHEAD OF THE FRONT...WHICH IS ALWAYS A PROBLEMATIC ELEMENT WHEN
FORECASTING PRECIPITATION FOR THE LOWCOUNTRY AND COASTAL EMPIRE.
BOTH THE 26/12Z GFS AND NAM WITH SUPPORT FROM THE LATEST SREF HAVE
PICKED UP ON THIS AND HAVE TRENDED DRIER FOR MUCH OF THE OVERNIGHT
PERIOD.

WILL LOWER POPS FOR TONIGHT ESPECIALLY DURING THE EVENING HOURS
WHERE LITTLE SIGNIFICANT SHOWER ACTIVITY IS EXPECTED...OUTSIDE OF
A FEW SHOWERS WHICH MAY BLEED INTO THE AREA FROM THE SOUTHWEST
PER LATEST KTLH/KVAX RADAR TRENDS. STILL EXPECT SCATTERED TO
PERHAPS NUMEROUS SHOWERS TO BREAK OUT JUST BEFORE SUNRISE AS THE
COLD FRONT DRAWS CLOSER AND LOW- LEVEL CONVERGENCE INCREASES...BUT
EVEN THIS MAY PROVE TO BE TOO QUICK IF MODELS CONTINUE TO TREND
SLOWER WITH THE PROGRESSION OF THE COLD FRONT. MAXIMUM POPS WILL
RANGE FROM 40-50 PERCENT AT THE COAST WITH 50-60 PERCENT INLAND.
LOWS WILL ONLY BOTTOM OUT IN THE LOWER 60S WITH A FEW UPPER 50S
ALONG THE BEACHES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE AFTERNOON INTO THIS EVENING...WITH INCREASING
CHANCES FOR MVFR CIGS AND RAIN SHOWERS AFTER 06Z. THE BULK OF THE
HEAVIEST RAINS WILL LIKELY HOLD OFF UNTIL CLOSER TO SUNRISE
FRIDAY...ALTHOUGH SOME GUIDANCE SUGGESTS EVEN LATER THAN THAT.
WILL INCLUDE PREVAILING 5SM -SHRA FROM 10Z ON AT BOTH TERMINALS.
WILL ALSO INCLUDE A TEMPO FOR BRIEF SHOWERS AT KSAV FROM ROUGHLY
23-01Z AS HIGH RESOLUTION DATA SUPPORT SHOWERS IN THAT AREA ALONG
THE SEA BREEZE.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA...AS A COLD FRONT
MOVES THROUGH THE AREA. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
SEA FOG...TRICKY SEA FOG FORECAST THROUGH THIS EVENING. LOW-LEVEL
WINDS HAVE TURNED A BIT MORE SOUTHEAST ALONG THE GEORGIA COAST
WHICH IS DIMINISHING PARCEL RESIDENCE TIMES ACROSS THE CORE OF THE
COLDER SHELF WATERS. THIS HAS RESULTED IN AN IMPROVEMENT IN VSBYS
ACROSS BOTH GEORGIA MARINE ZONES. FARTHER NORTH...SOUTHWEST WINDS
HAVE NOT SHOWN ANY INDICATION OF BACKING WITH THE SEA BREEZE...SO
WIDESPREAD DENSE SEA FOG LINGERS. HIGH RESOLUTION MODELS SUGGEST
MOST OF THE FOG ALONG THE LOWER SOUTH CAROLINA COASTAL WATER...OR
AT LEAST A GOOD PORTION OF IT...WILL LIKELY LIFT OR THIN OUT AS
WINDS EVENTUALLY BACK WITH THE STRENGTHENING SEA BREEZE
CIRCULATION. THIS TREND IS SUPPORTED BY BOTH THE RAP AND H3R VSBY
PROGS WHICH HAVE DONE QUITE WELL SO FAR TODAY.

WILL TAKE THE DENSE FOG ADVISORY UNTIL 6 PM FOR THE SOUTH
CAROLINA COASTAL MARINE ZONES...BUT CANCEL IT FOR THE GEORGIA
MARINE ZONES. ATTM IT APPEARS THERE WILL BE ENOUGH MIXING AROUND
CHARLESTON HARBOR FOR THE FOG TO MAKE TOO MUCH PROGRESS INTO THE
MAIN HARBOR ITSELF...BUT WILL MORE LIKELY REMAIN JUST AT THE
HARBOR ENTRANCE AROUND FORT SUMTER. WILL NOT ISSUE A DENSE FOG
ADVISORY FOR THE HARBOR ATTM. THE RISK FOR AT LEAST PATCHY FOG
WILL LINGER THROUGH THE NIGHT AS WINDS EVENTUALLY VEER AHEAD OF
THE COLD FRONT.

TONIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF AN
APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND GUSTS
AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WILL BE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR AMZ350-352.
     SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$

ST/WMS




000
FXUS62 KCHS 262015
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
415 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH THE REGION FRIDAY.
COLDER HIGH PRESSURE WILL THEN BUILD FOR THE WEEKEND SUPPORTING A
POSSIBLE FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE
THEN SHIFTS SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT
MOVES THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL
THEN PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE AREA WILL REMAIN WELL WITHIN THE WARM SECTOR TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. FAVORABLE UVM INDUCED BY THE RIGHT
ENTRANCE REGION OF A DEPARTING 250 HPA JET STREAK COUPLED WITH A
850 HPA 30-35 KT LOW-LEVEL JET AND RIBBON OF PWATS APPROACHING
1.50 INCHES WILL SUPPORT SOME SHOWER ACTIVITY OVERNIGHT...HOWEVER
IT IS UNCLEAR EXACTLY HOW WIDESPREAD THIS ACTIVITY WILL BECOME AS
EXTENSIVE CONVECTION ALONG THE GULF COAST IS FORECAST TO PERSIST
THROUGH THE NIGHT. THIS AREA OF CONVECTION WILL TEND TO DISRUPT
THE NECESSARY LOW-LEVEL INFLOW OF GULF MOISTURE INTO THE REGION
AHEAD OF THE FRONT...WHICH IS ALWAYS A PROBLEMATIC ELEMENT WHEN
FORECASTING PRECIPITATION FOR THE LOWCOUNTRY AND COASTAL EMPIRE.
BOTH THE 26/12Z GFS AND NAM WITH SUPPORT FROM THE LATEST SREF HAVE
PICKED UP ON THIS AND HAVE TRENDED DRIER FOR MUCH OF THE OVERNIGHT
PERIOD.

WILL LOWER POPS FOR TONIGHT ESPECIALLY DURING THE EVENING HOURS
WHERE LITTLE SIGNIFICANT SHOWER ACTIVITY IS EXPECTED...OUTSIDE OF
A FEW SHOWERS WHICH MAY BLEED INTO THE AREA FROM THE SOUTHWEST
PER LATEST KTLH/KVAX RADAR TRENDS. STILL EXPECT SCATTERED TO
PERHAPS NUMEROUS SHOWERS TO BREAK OUT JUST BEFORE SUNRISE AS THE
COLD FRONT DRAWS CLOSER AND LOW- LEVEL CONVERGENCE INCREASES...BUT
EVEN THIS MAY PROVE TO BE TOO QUICK IF MODELS CONTINUE TO TREND
SLOWER WITH THE PROGRESSION OF THE COLD FRONT. MAXIMUM POPS WILL
RANGE FROM 40-50 PERCENT AT THE COAST WITH 50-60 PERCENT INLAND.
LOWS WILL ONLY BOTTOM OUT IN THE LOWER 60S WITH A FEW UPPER 50S
ALONG THE BEACHES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A SURFACE TROUGH WILL BE LOCATED ALONG THE MID ATLANTIC
AND SOUTHEAST COASTLINE BY DAYBREAK...WITH A STRONG COLD FRONT
STEADILY DESCENDING FROM THE UPSTATE REGION. THERE IS EVIDENCE OF
A DRY SLOT DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA AHEAD
OF THE APPROACHING COLD FRONT DURING THE MORNING HOURS...LENDING
SOME UNCERTAINTY TO TIMING AND COVERAGE OF RAIN ASSOCIATED WITH
THE FRONTAL PASSAGE. CONSIDERING DEEP MOISTURE ACROSS THE
REGION...A STRONG MID/UPPER LEVEL JET INTENSIFYING OVER THE
AREA...AND DECENT CONVERGENCE ALONG THE FRONTAL ZONE...PREFER TO
INDICATE RAIN CHANCES INCREASING THROUGH THE MORNING HOURS INTO
THE LIKELY RANGE FOR MOST LOCATIONS. WILL ADVERTISE HIGHEST
POTENTIAL DURING THE LATE MORNING AND EARLY AFTERNOON...WITH
FAVORED LOCATIONS TO THE NORTH AND EAST...INCLUDING THE CHARLESTON
TRI COUNTY AND ALONG THE COASTLINE. RAIN CHANCES WILL THEN
DECREASE FROM WEST TO EAST LATER IN THE AFTERNOON...AS THE COLD
FRONT CROSSES THE FORECAST AREA AHEAD OF STRONG SHORTWAVE ENERGY
APPROACHING FROM THE WEST. HIGH TEMPERATURES ON FRIDAY WILL LIKELY
BE REACHED BY EARLY AFTERNOON...WITH A COOLING TREND INTO LATE
AFTERNOON. TEMPERATURES WILL PEAK IN THE MID 60S NORTH TO THE LOW
70S SOUTH.

FRIDAY NIGHT...THE COLD FRONT WILL RAPIDLY EXIT THE COASTLINE AND
PROCEED INTO THE ATLANTIC DURING THE EVENING HOURS...WITH STRONG
SURFACE HIGH PRESSURE BUILDING IN ITS WAKE. NORTHERN AND SOUTHERN
STREAM ENERGY WILL MERGE INTO AN AMPLIFYING UPPER TROUGH THAT
SHIFTS DIRECTLY OVER THE COAST AFTER MIDNIGHT. RATHER SIGNIFICANT
UPPER LEVEL FORCING COULD THUS SUPPORT A FEW ISOLATED SHOWERS
ACROSS NORTHERN BERKELEY AND CHARLESTON COUNTIES BETWEEN MIDNIGHT
AND DAWN SATURDAY MORNING. THERE REMAINS A SMALL POTENTIAL FOR
ISOLATED GRAUPEL OR SOFT HAIL CONSIDERING SUCH COLD AIR ALOFT AND
DECENT LARGE SCALE FORCING. HOWEVER...TEMPERATURES AT THE SURFACE
WILL REMAIN ABOVE FREEZING...WITH LOWS IN THE UPPER 30S TO LOW
40S. WIND SPEEDS APPEAR TO HIGH OVERNIGHT...AND GROUNDS WILL
LIKELY BE TOO WET...TO SUPPORT FROST DEVELOPMENT.

SATURDAY...THE DEEP UPPER LEVEL TROUGH WILL LINGER ALONG THE
EASTERN THIRD OF THE UNITED STATES...WHILE COLD CANADIAN HIGH
PRESSURE SHIFTS TOWARD THE EAST COAST. DESPITE DRY CONDITIONS AND
MOSTLY SUNNY SKIES...TEMPERATURES WILL REMAIN SUPPRESSED IN THE
UPPER 50S TO AROUND 60 DEGREES WITHIN BREEZY WEST/NORTHWEST
WINDS...10 TO 15 DEGREES BELOW SEASONAL NORMALS. ADDITIONAL
SHORTWAVE ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION
WILL HELP REINFORCE THE STALLED UPPER TROUGH OVERNIGHT...WITH THE
CENTER OF THE SURFACE HIGH SETTLING DIRECTLY OVER THE REGION. LOW
TEMPERATURES SATURDAY NIGHT WILL REACH THE LOW 30S INLAND TO THE
MID/UPPER 30S CLOSER TO THE COAST. A LIGHT FREEZE REMAINS POSSIBLE
FOR FAR INLAND COUNTIES...WHERE TEMPERATURES COULD REACH 32
DEGREES FOR AN HOUR OR TWO. IT SHOULD BE NOTED THAT IF
NIGHTTIME/EARLY MORNING WIND SPEEDS CAN DIMINISH MORE THAN
CURRENTLY FORECAST...THEN TEMPERATURES COULD BE EVEN COLDER AND
FROST WOULD ALSO BE A CONCERN.

SUNDAY...THE SURFACE HIGH WILL STEADILY DESCEND TOWARD THE
SOUTHEAST COAST...AS THE UPPER TROUGH MOVES INTO THE ATLANTIC.
TEMPERATURES WILL MODERATE JUST A DEGREE OR TWO...AND THUS DESPITE
ANOTHER SUNNY AND DRY DAY...EXPECT HIGHS TO ONLY REACH THE UPPER
50S TO LOW 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE AFTERNOON INTO THIS EVENING...WITH INCREASING
CHANCES FOR MVFR CIGS AND RAIN SHOWERS AFTER 06Z. THE BULK OF THE
HEAVIEST RAINS WILL LIKELY HOLD OFF UNTIL CLOSER TO SUNRISE
FRIDAY...ALTHOUGH SOME GUIDANCE SUGGESTS EVEN LATER THAN THAT.
WILL INCLUDE PREVAILING 5SM -SHRA FROM 10Z ON AT BOTH TERMINALS.
WILL ALSO INCLUDE A TEMPO FOR BRIEF SHOWERS AT KSAV FROM ROUGHLY
23-01Z AS HIGH RESOLUTION DATA SUPPORT SHOWERS IN THAT AREA ALONG
THE SEA BREEZE.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA...AS A COLD FRONT
MOVES THROUGH THE AREA. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...BEFORE POSSIBLE SUB-VFR WEATHER ACCOMPANIES ANOTHER
COLD FRONT LATE MONDAY.

&&

.MARINE...
SEA FOG...TRICKY SEA FOG FORECAST THROUGH THIS EVENING. LOW-LEVEL
WINDS HAVE TURNED A BIT MORE SOUTHEAST ALONG THE GEORGIA COAST
WHICH IS DIMINISHING PARCEL RESIDENCE TIMES ACROSS THE CORE OF THE
COLDER SHELF WATERS. THIS HAS RESULTED IN AN IMPROVEMENT IN VSBYS
ACROSS BOTH GEORGIA MARINE ZONES. FARTHER NORTH...SOUTHWEST WINDS
HAVE NOT SHOWN ANY INDICATION OF BACKING WITH THE SEA BREEZE...SO
WIDESPREAD DENSE SEA FOG LINGERS. HIGH RESOLUTION MODELS SUGGEST
MOST OF THE FOG ALONG THE LOWER SOUTH CAROLINA COASTAL WATER...OR
AT LEAST A GOOD PORTION OF IT...WILL LIKELY LIFT OR THIN OUT AS
WINDS EVENTUALLY BACK WITH THE STRENGTHENING SEA BREEZE
CIRCULATION. THIS TREND IS SUPPORTED BY BOTH THE RAP AND H3R VSBY
PROGS WHICH HAVE DONE QUITE WELL SO FAR TODAY.

WILL TAKE THE DENSE FOG ADVISORY UNTIL 6 PM FOR THE SOUTH
CAROLINA COASTAL MARINE ZONES...BUT CANCEL IT FOR THE GEORGIA
MARINE ZONES. ATTM IT APPEARS THERE WILL BE ENOUGH MIXING AROUND
CHARLESTON HARBOR FOR THE FOG TO MAKE TOO MUCH PROGRESS INTO THE
MAIN HARBOR ITSELF...BUT WILL MORE LIKELY REMAIN JUST AT THE
HARBOR ENTRANCE AROUND FORT SUMTER. WILL NOT ISSUE A DENSE FOG
ADVISORY FOR THE HARBOR ATTM. THE RISK FOR AT LEAST PATCHY FOG
WILL LINGER THROUGH THE NIGHT AS WINDS EVENTUALLY VEER AHEAD OF
THE COLD FRONT.

TONIGHT...SOUTH WINDS WILL VEER SOUTHWEST AND INCREASE AHEAD OF AN
APPROACHING COLD FRONT. THE COMBINATION OF INCREASING WIND GUSTS
AND SLOWLY BUILDING SEAS WILL SUPPORT SMALL CRAFT ADVISORY
CONDITIONS OVER BOTH THE CHARLESTON COUNTY NEARSHORE WATERS AND
THE GEORGIA OFFSHORE WATERS EARLY FRIDAY MORNING. FLAGS WILL BE
RAISED FOR THESE TWO ZONES WITH THE LATE AFTERNOON FORECAST
PACKAGE. WINDS AND SEAS WILL BE A BIT LESS FOR THE REMAINING
MARINE ZONES WITH SEAS ONLY REACHING 3-5 FT WITH WINDS 15-20 KT.

FRIDAY...THE COMBINATION OF A TIGHT PRESSURE GRADIENT AHEAD AND
ALONG A COLD FRONT...AS WELL AS MIXING IN THE WAKE OF THE
FRONT...WILL SUPPORT GUSTS UP TO 25 KT AND SEAS PEAKING AT 6
FT FOR THE CHARLESTON COUNTY WATERS OFFSHORE GEORGIA MARINE
ZONES. SMALL CRAFT ADVISORIES HAVE THUS BEEN ISSUED FOR THESE
MARINE ZONES. ALTHOUGH WIND FIELDS WILL BE SOMEWHAT ELEVATED AHEAD
OF THE FRONT...SEA FOG WILL PERSIST UNTIL THE FRONT PASSES THROUGH
THE AREA. CONDITIONS WILL FALL BELOW ADVISORY THRESHOLDS FOR THE
CHARLESTON WATERS DURING THE AFTERNOON...YET PERSIST BEYOND 20 NM.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE FOR THE OUTER GEORGIA WATERS THROUGH THE MORNING
HOURS....ENDING BY EARLY AFTERNOON. STRONG CONTINENTAL HIGH
PRESSURE WILL BUILD FROM THE NORTHWEST AND SUPPORT A SURGE IN
NORTH/NORTHEAST WINDS AROUND DAYBREAK SUNDAY. HOWEVER...EXPECT
WINDS AND SEAS TO REMAIN BELOW ADVISORY CRITERIA. THE HIGH
PRESSURE CENTER WILL THEN SETTLE DIRECTLY OVER THE WATERS BY LATE
IN THE DAY...AND WINDS AND SEAS WILL DIMINISH ACCORDINGLY.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND SEAS WILL BE LESS THAN 3 TO 5 FT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR AMZ350-352.
     SMALL CRAFT ADVISORY FROM 5 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.
     SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT FRIDAY FOR AMZ350.

&&

$$

ST/WMS





000
FXUS62 KCHS 261656
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1256 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES WERE MADE WITH THE EARLY AFTERNOON UPDATE.
LOCALLY DENSE SEA FOG WILL AFFECT THE COASTAL COMMUNITIES FROM
EDISTO BEACH NORTHEAST ALONG THE CHARLESTON COUNTY COAST FOR A FEW
HOURS THIS AFTERNOON. IT IS UNCLEAR HOW FAR INLAND THE FOG BANK
WILL PENETRATE AS THE SEA BREEZE DEVELOPS...BUT TRENDS ARE BEING
WATCHED.

THE RISK FOR SHOWER ACTIVITY LOOKS MINIMAL WITH MODIFIED OBSERVED
AND FORECAST SOUNDINGS SHOWING LITTLE IN THE WAY OF INSTABILITY.
THIS IS SUPPORTED BY THE LATEST RAP AND H3R RUNS. THE BEST RAIN
CHANCES WILL HOLD OFF UNTIL AFTER 6 PM AS A COLD FRONT AND
ASSOCIATED SHORTWAVE ENERGY DRAW CLOSER. COULD SEE AN ISOLATED
SHOWER DEVELOP ALONG THE RESULTANT SEA BREEZE ITSELF WHERE LOW-
LEVEL MOISTURE FLUX CONVERGENCE WILL BE LOCALLY MAXIMIZED... BUT
THE OVERALL RISK FOR THIS IS TOO SMALL TO JUSTIFY A MENTIONABLE
POP ATTM. WILL CONTINUE TO MONITOR CONVECTIVE TRENDS THROUGH THE
DAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE AFTERNOON INTO THIS EVENING...WITH INCREASING
CHANCES FOR MVFR CIGS AND RAIN SHOWERS AFTER 06Z. THE BULK OF THE
HEAVIEST RAINS WILL LIKELY HOLD OFF UNTIL CLOSER TO SUNRISE
FRIDAY...ALTHOUGH SOME GUIDANCE SUGGESTS EVEN LATER THAN THAT.
WILL INCLUDE PREVAILING 5SM -SHRA FROM 10Z ON AT BOTH TERMINALS.
WILL ALSO INCLUDE A TEMPO FOR BRIEF SHOWERS AT KSAV FROM ROUGHLY
23-01Z AS HIGH RESOLUTION DATA SUPPORT SHOWERS IN THAT AREA ALONG
THE SEA BREEZE.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
EXPANDED THE MARINE DENSE FOG ADV NORTHEAST TO THE CHARLESTON
COUNTY WATERS AND THE GEORGIA OFFSHORE WATER PER SATELLITE TRENDS
AND WEBCAM OBSERVATIONS.

TODAY...WEBCAMS OFF HILTON HEAD AND EDISTO BEACH SUGGEST THE SEA
FOG HAS LIFTED SOME OVER THE PAST 1-2 HOURS. HOWEVER...WINDS ARE
FORECAST TO RETURN TO A MOVE SOUTHERLY DIRECTION AS THE MORNING
LAND BREEZE DISSIPATES AND A SEA BREEZE INITIATES. THIS WILL
RETURN THE LOW- LEVEL FLOW TO A MORE FAVORABLE GEOMETRY FOR SEA
FOG DEVELOPMENT. WILL MAINTAIN THE MARINE DENSE FOG ADVISORY FOR
THE NEARSHORE WATERS FROM EDISTO BEACH SOUTH. THE FOG COULD EXPAND
INTO THE CHARLESTON COUNTY WATERS LATER THIS AFTERNOON...SO THE
ADVISORY MAY NEED TO BE EXPANDED WITH LATER FORECAST CYCLES.

TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD FRONT LATE
TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE CREATING A
GOOD ENVIRONMENT FOR SEA FOG. WINDS/SEAS WILL APPROACH SMALL CRAFT
ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     DENSE FOG ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ350-
     374.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$

ST





000
FXUS62 KCHS 261656
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1256 PM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES WERE MADE WITH THE EARLY AFTERNOON UPDATE.
LOCALLY DENSE SEA FOG WILL AFFECT THE COASTAL COMMUNITIES FROM
EDISTO BEACH NORTHEAST ALONG THE CHARLESTON COUNTY COAST FOR A FEW
HOURS THIS AFTERNOON. IT IS UNCLEAR HOW FAR INLAND THE FOG BANK
WILL PENETRATE AS THE SEA BREEZE DEVELOPS...BUT TRENDS ARE BEING
WATCHED.

THE RISK FOR SHOWER ACTIVITY LOOKS MINIMAL WITH MODIFIED OBSERVED
AND FORECAST SOUNDINGS SHOWING LITTLE IN THE WAY OF INSTABILITY.
THIS IS SUPPORTED BY THE LATEST RAP AND H3R RUNS. THE BEST RAIN
CHANCES WILL HOLD OFF UNTIL AFTER 6 PM AS A COLD FRONT AND
ASSOCIATED SHORTWAVE ENERGY DRAW CLOSER. COULD SEE AN ISOLATED
SHOWER DEVELOP ALONG THE RESULTANT SEA BREEZE ITSELF WHERE LOW-
LEVEL MOISTURE FLUX CONVERGENCE WILL BE LOCALLY MAXIMIZED... BUT
THE OVERALL RISK FOR THIS IS TOO SMALL TO JUSTIFY A MENTIONABLE
POP ATTM. WILL CONTINUE TO MONITOR CONVECTIVE TRENDS THROUGH THE
DAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH THE AFTERNOON INTO THIS EVENING...WITH INCREASING
CHANCES FOR MVFR CIGS AND RAIN SHOWERS AFTER 06Z. THE BULK OF THE
HEAVIEST RAINS WILL LIKELY HOLD OFF UNTIL CLOSER TO SUNRISE
FRIDAY...ALTHOUGH SOME GUIDANCE SUGGESTS EVEN LATER THAN THAT.
WILL INCLUDE PREVAILING 5SM -SHRA FROM 10Z ON AT BOTH TERMINALS.
WILL ALSO INCLUDE A TEMPO FOR BRIEF SHOWERS AT KSAV FROM ROUGHLY
23-01Z AS HIGH RESOLUTION DATA SUPPORT SHOWERS IN THAT AREA ALONG
THE SEA BREEZE.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
EXPANDED THE MARINE DENSE FOG ADV NORTHEAST TO THE CHARLESTON
COUNTY WATERS AND THE GEORGIA OFFSHORE WATER PER SATELLITE TRENDS
AND WEBCAM OBSERVATIONS.

TODAY...WEBCAMS OFF HILTON HEAD AND EDISTO BEACH SUGGEST THE SEA
FOG HAS LIFTED SOME OVER THE PAST 1-2 HOURS. HOWEVER...WINDS ARE
FORECAST TO RETURN TO A MOVE SOUTHERLY DIRECTION AS THE MORNING
LAND BREEZE DISSIPATES AND A SEA BREEZE INITIATES. THIS WILL
RETURN THE LOW- LEVEL FLOW TO A MORE FAVORABLE GEOMETRY FOR SEA
FOG DEVELOPMENT. WILL MAINTAIN THE MARINE DENSE FOG ADVISORY FOR
THE NEARSHORE WATERS FROM EDISTO BEACH SOUTH. THE FOG COULD EXPAND
INTO THE CHARLESTON COUNTY WATERS LATER THIS AFTERNOON...SO THE
ADVISORY MAY NEED TO BE EXPANDED WITH LATER FORECAST CYCLES.

TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD FRONT LATE
TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE CREATING A
GOOD ENVIRONMENT FOR SEA FOG. WINDS/SEAS WILL APPROACH SMALL CRAFT
ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     DENSE FOG ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ350-
     374.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$

ST




000
FXUS62 KCHS 261357
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
957 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE REGION WILL REMAIN SOLIDLY WITHIN THE WARM SECTOR TODAY AHEAD
OF AN APPROACHING COLD FRONT. EXTENSIVE LOW CLOUDS ARE BEGINNING
TO THIN AND BREAK UP PER LATEST SATELLITE TRENDS. THIS INCREASED
INSOLATION COUPLED WITH 850 HPA TEMPERATURES APPROACHING 12C WILL
SUPPORT HIGHS NEAR 80-82F MOST LOCATIONS AWAY FROM THE BEACHES
THIS AFTERNOON. CLOUDS WILL BEGIN TO THICKEN UP LATER THIS
AFTERNOON AS HIGH CLOUDS INCREASE AND A CUMULUS FIELD DEVELOPS...
WHICH WILL RETURN THE SKY CHARACTER BACK TO PARTLY SUNNY TO
MOSTLY CLOUDY.

THE RISK FOR SHOWER ACTIVITY LOOKS MINIMAL WITH MODIFIED OBSERVED
AND FORECAST SOUNDINGS SHOWING LITTLE IN THE WAY OF INSTABILITY.
THIS IS SUPPORTED BY THE LATEST RAP AND H3R RUNS. THE BEST RAIN
CHANCES WILL HOLD OFF UNTIL AFTER 6 PM AS A COLD FRONT AND
ASSOCIATED SHORTWAVE ENERGY DRAW CLOSER. COULD SEE AN ISOLATED
SHOWER DEVELOP ALONG THE RESULTANT SEA BREEZE ITSELF WHERE LOW-
LEVEL MOISTURE FLUX CONVERGENCE WILL BE LOCALLY MAXIMIZED... BUT
THE OVERALL RISK FOR THIS IS TOO SMALL TO JUSTIFY A MENTIONABLE
POP ATTM. WILL CONTINUE TO MONITOR CONVECTIVE TRENDS THROUGH THE
DAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
KCHS...IFR/LIFR CONDITIONS THROUGH 14Z WILL GIVE WAY TO A RETURN
OF VFR WEATHER FOR THE BALANCE OF THE DAY AS INVERSION WEAKENS AND
LIFTS HIGHER. SOUTH/SW WINDS WILL BE GUSTY DURING THE AFTERNOON AS
UNSEASONABLY TEMPS PREVAIL IN ADVANCE OF A COLD FRONT...WHILE
ENHANCEMENT ALSO OCCURS FROM SEA BREEZE INFLUENCES. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH THE OPTION FOR ADJUSTMENTS AT A LATER TIME.

KSAV...A SHARP INVERSION WILL KEEP THE AIRFIELD LOCKED IN WITH
LIFR CONDITIONS AND NEAR AIRPORT MINIMUMS THROUGH 14Z...BEFORE
IMPROVING BACK TO VFR BY 15Z AS THE INVERSION BREAKS AND MOISTURE
SCOURS OUT. GUSTY SOUTH/SW WINDS WILL THEN PREVAIL FOR THE
HEATING OF THE AFTERNOON IN ADVANCE OF A COLD FRONT...WITH
ADDITIONAL IMPETUS FROM THE SEA BREEZE. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH FUTURE ADJUSTMENTS LIKELY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY...WEBCAMS OFF HILTON HEAD AND EDISTO BEACH SUGGEST THE SEA
FOG HAS LIFTED SOME OVER THE PAST 1-2 HOURS. HOWEVER...WINDS ARE
FORECAST TO RETURN TO A MOVE SOUTHERLY DIRECTION AS THE MORNING
LAND BREEZE DISSIPATES AND A SEA BREEZE INITIATES. THIS WILL
RETURN THE LOW- LEVEL FLOW TO A MORE FAVORABLE GEOMETRY FOR SEA
FOG DEVELOPMENT. WILL MAINTAIN THE MARINE DENSE FOG ADVISORY FOR
THE NEARSHORE WATERS FROM EDISTO BEACH SOUTH. THE FOG COULD EXPAND
INTO THE CHARLESTON COUNTY WATERS LATER THIS AFTERNOON...SO THE
ADVISORY MAY NEED TO BE EXPANDED WITH LATER FORECAST CYCLES.

TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD FRONT LATE
TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE CREATING A
GOOD ENVIRONMENT FOR SEA FOG. WINDS/SEAS WILL APPROACH SMALL CRAFT
ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$




000
FXUS62 KCHS 261357
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
957 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE REGION WILL REMAIN SOLIDLY WITHIN THE WARM SECTOR TODAY AHEAD
OF AN APPROACHING COLD FRONT. EXTENSIVE LOW CLOUDS ARE BEGINNING
TO THIN AND BREAK UP PER LATEST SATELLITE TRENDS. THIS INCREASED
INSOLATION COUPLED WITH 850 HPA TEMPERATURES APPROACHING 12C WILL
SUPPORT HIGHS NEAR 80-82F MOST LOCATIONS AWAY FROM THE BEACHES
THIS AFTERNOON. CLOUDS WILL BEGIN TO THICKEN UP LATER THIS
AFTERNOON AS HIGH CLOUDS INCREASE AND A CUMULUS FIELD DEVELOPS...
WHICH WILL RETURN THE SKY CHARACTER BACK TO PARTLY SUNNY TO
MOSTLY CLOUDY.

THE RISK FOR SHOWER ACTIVITY LOOKS MINIMAL WITH MODIFIED OBSERVED
AND FORECAST SOUNDINGS SHOWING LITTLE IN THE WAY OF INSTABILITY.
THIS IS SUPPORTED BY THE LATEST RAP AND H3R RUNS. THE BEST RAIN
CHANCES WILL HOLD OFF UNTIL AFTER 6 PM AS A COLD FRONT AND
ASSOCIATED SHORTWAVE ENERGY DRAW CLOSER. COULD SEE AN ISOLATED
SHOWER DEVELOP ALONG THE RESULTANT SEA BREEZE ITSELF WHERE LOW-
LEVEL MOISTURE FLUX CONVERGENCE WILL BE LOCALLY MAXIMIZED... BUT
THE OVERALL RISK FOR THIS IS TOO SMALL TO JUSTIFY A MENTIONABLE
POP ATTM. WILL CONTINUE TO MONITOR CONVECTIVE TRENDS THROUGH THE
DAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
KCHS...IFR/LIFR CONDITIONS THROUGH 14Z WILL GIVE WAY TO A RETURN
OF VFR WEATHER FOR THE BALANCE OF THE DAY AS INVERSION WEAKENS AND
LIFTS HIGHER. SOUTH/SW WINDS WILL BE GUSTY DURING THE AFTERNOON AS
UNSEASONABLY TEMPS PREVAIL IN ADVANCE OF A COLD FRONT...WHILE
ENHANCEMENT ALSO OCCURS FROM SEA BREEZE INFLUENCES. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH THE OPTION FOR ADJUSTMENTS AT A LATER TIME.

KSAV...A SHARP INVERSION WILL KEEP THE AIRFIELD LOCKED IN WITH
LIFR CONDITIONS AND NEAR AIRPORT MINIMUMS THROUGH 14Z...BEFORE
IMPROVING BACK TO VFR BY 15Z AS THE INVERSION BREAKS AND MOISTURE
SCOURS OUT. GUSTY SOUTH/SW WINDS WILL THEN PREVAIL FOR THE
HEATING OF THE AFTERNOON IN ADVANCE OF A COLD FRONT...WITH
ADDITIONAL IMPETUS FROM THE SEA BREEZE. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH FUTURE ADJUSTMENTS LIKELY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY...WEBCAMS OFF HILTON HEAD AND EDISTO BEACH SUGGEST THE SEA
FOG HAS LIFTED SOME OVER THE PAST 1-2 HOURS. HOWEVER...WINDS ARE
FORECAST TO RETURN TO A MOVE SOUTHERLY DIRECTION AS THE MORNING
LAND BREEZE DISSIPATES AND A SEA BREEZE INITIATES. THIS WILL
RETURN THE LOW- LEVEL FLOW TO A MORE FAVORABLE GEOMETRY FOR SEA
FOG DEVELOPMENT. WILL MAINTAIN THE MARINE DENSE FOG ADVISORY FOR
THE NEARSHORE WATERS FROM EDISTO BEACH SOUTH. THE FOG COULD EXPAND
INTO THE CHARLESTON COUNTY WATERS LATER THIS AFTERNOON...SO THE
ADVISORY MAY NEED TO BE EXPANDED WITH LATER FORECAST CYCLES.

TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD FRONT LATE
TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE CREATING A
GOOD ENVIRONMENT FOR SEA FOG. WINDS/SEAS WILL APPROACH SMALL CRAFT
ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$





000
FXUS62 KCHS 261357
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
957 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE REGION WILL REMAIN SOLIDLY WITHIN THE WARM SECTOR TODAY AHEAD
OF AN APPROACHING COLD FRONT. EXTENSIVE LOW CLOUDS ARE BEGINNING
TO THIN AND BREAK UP PER LATEST SATELLITE TRENDS. THIS INCREASED
INSOLATION COUPLED WITH 850 HPA TEMPERATURES APPROACHING 12C WILL
SUPPORT HIGHS NEAR 80-82F MOST LOCATIONS AWAY FROM THE BEACHES
THIS AFTERNOON. CLOUDS WILL BEGIN TO THICKEN UP LATER THIS
AFTERNOON AS HIGH CLOUDS INCREASE AND A CUMULUS FIELD DEVELOPS...
WHICH WILL RETURN THE SKY CHARACTER BACK TO PARTLY SUNNY TO
MOSTLY CLOUDY.

THE RISK FOR SHOWER ACTIVITY LOOKS MINIMAL WITH MODIFIED OBSERVED
AND FORECAST SOUNDINGS SHOWING LITTLE IN THE WAY OF INSTABILITY.
THIS IS SUPPORTED BY THE LATEST RAP AND H3R RUNS. THE BEST RAIN
CHANCES WILL HOLD OFF UNTIL AFTER 6 PM AS A COLD FRONT AND
ASSOCIATED SHORTWAVE ENERGY DRAW CLOSER. COULD SEE AN ISOLATED
SHOWER DEVELOP ALONG THE RESULTANT SEA BREEZE ITSELF WHERE LOW-
LEVEL MOISTURE FLUX CONVERGENCE WILL BE LOCALLY MAXIMIZED... BUT
THE OVERALL RISK FOR THIS IS TOO SMALL TO JUSTIFY A MENTIONABLE
POP ATTM. WILL CONTINUE TO MONITOR CONVECTIVE TRENDS THROUGH THE
DAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
KCHS...IFR/LIFR CONDITIONS THROUGH 14Z WILL GIVE WAY TO A RETURN
OF VFR WEATHER FOR THE BALANCE OF THE DAY AS INVERSION WEAKENS AND
LIFTS HIGHER. SOUTH/SW WINDS WILL BE GUSTY DURING THE AFTERNOON AS
UNSEASONABLY TEMPS PREVAIL IN ADVANCE OF A COLD FRONT...WHILE
ENHANCEMENT ALSO OCCURS FROM SEA BREEZE INFLUENCES. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH THE OPTION FOR ADJUSTMENTS AT A LATER TIME.

KSAV...A SHARP INVERSION WILL KEEP THE AIRFIELD LOCKED IN WITH
LIFR CONDITIONS AND NEAR AIRPORT MINIMUMS THROUGH 14Z...BEFORE
IMPROVING BACK TO VFR BY 15Z AS THE INVERSION BREAKS AND MOISTURE
SCOURS OUT. GUSTY SOUTH/SW WINDS WILL THEN PREVAIL FOR THE
HEATING OF THE AFTERNOON IN ADVANCE OF A COLD FRONT...WITH
ADDITIONAL IMPETUS FROM THE SEA BREEZE. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH FUTURE ADJUSTMENTS LIKELY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY...WEBCAMS OFF HILTON HEAD AND EDISTO BEACH SUGGEST THE SEA
FOG HAS LIFTED SOME OVER THE PAST 1-2 HOURS. HOWEVER...WINDS ARE
FORECAST TO RETURN TO A MOVE SOUTHERLY DIRECTION AS THE MORNING
LAND BREEZE DISSIPATES AND A SEA BREEZE INITIATES. THIS WILL
RETURN THE LOW- LEVEL FLOW TO A MORE FAVORABLE GEOMETRY FOR SEA
FOG DEVELOPMENT. WILL MAINTAIN THE MARINE DENSE FOG ADVISORY FOR
THE NEARSHORE WATERS FROM EDISTO BEACH SOUTH. THE FOG COULD EXPAND
INTO THE CHARLESTON COUNTY WATERS LATER THIS AFTERNOON...SO THE
ADVISORY MAY NEED TO BE EXPANDED WITH LATER FORECAST CYCLES.

TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD FRONT LATE
TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE CREATING A
GOOD ENVIRONMENT FOR SEA FOG. WINDS/SEAS WILL APPROACH SMALL CRAFT
ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$





000
FXUS62 KCHS 261124
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
724 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...MORNING LOW CLOUDS/FOG WILL CLEAR BY 9 OR 10 AM...EXCEPT
POSSIBLY LINGERING NEAR THE COAST MUCH IF NOT ALL OF THE DAY. SOME
OF THE FOG COULD BE DENSE BUT WE DO NOT THINK IT WILL BE
WIDESPREAD ENOUGH TO WARRANT AN ADVISORY GIVEN SOME MIXING FROM
THE LOW-LEVEL JET. PROBABLY THE BEST RISK FOR DENSE FOG WILL COME
FROM ANY SEA FOG THAT DEVELOPS OVER THE NEARBY ATLANTIC AND PUSHES
INLAND.

THE AREA WILL BECOME INCREASINGLY IN THE WARM SECTOR AHEAD OF AN
APPROACHING COLD FRONT. AS THE LOW LEVEL FLOW VEERS TO
SOUTH/SOUTHWEST THE SHOWERS ACROSS THE ATLANTIC THIS MORNING WILL
REMAIN OFFSHORE. IT WILL THEN REMAIN DRY UNTIL LATE AFTERNOON
WHEN DEEP MOISTURE BEGINS TO ADVECT BACK IN FROM THE SOUTHWEST AND
A RESULTANT SEA BREEZE DEVELOPS. THUS...RAIN CHANCES WILL BE ON
THE INCREASE FROM THE SOUTH WITH THE POTENTIAL FOR SOME WEAK
THUNDERSTORMS TOWARD LATE AFTERNOON...MAINLY OVER SOUTHEAST
GEORGIA. HIGHS SHOULD PUSH INTO THE LOWER 80S MOST PLACES INLAND
AWAY FROM THE COOLER COASTAL AREAS.

TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
KCHS...IFR/LIFR CONDITIONS THROUGH 14Z WILL GIVE WAY TO A RETURN
OF VFR WEATHER FOR THE BALANCE OF THE DAY AS INVERSION WEAKENS AND
LIFTS HIGHER. SOUTH/SW WINDS WILL BE GUSTY DURING THE AFTERNOON AS
UNSEASONABLY TEMPS PREVAIL IN ADVANCE OF A COLD FRONT...WHILE
ENHANCEMENT ALSO OCCURS FROM SEA BREEZE INFLUENCES. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH THE OPTION FOR ADJUSTMENTS AT A LATER TIME.

KSAV...A SHARP INVERSION WILL KEEP THE AIRFIELD LOCKED IN WITH
LIFR CONDITIONS AND NEAR AIRPORT MINIMUMS THROUGH 14Z...BEFORE
IMPROVING BACK TO VFR BY 15Z AS THE INVERSION BREAKS AND MOISTURE
SCOURS OUT. GUSTY SOUTH/SW WINDS WILL THEN PREVAIL FOR THE
HEATING OF THE AFTERNOON IN ADVANCE OF A COLD FRONT...WITH
ADDITIONAL IMPETUS FROM THE SEA BREEZE. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH FUTURE ADJUSTMENTS LIKELY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY AND TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD
FRONT LATE TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE
CREATING A GOOD ENVIRONMENT FOR SEA FOG. BASED ON REPORTS FROM THE
PORT OF SAVANNAH...WEBCAMS...COASTAL OBSERVATIONAL SITES AND
GOES-E PRODUCTS WE HAVE RAISED A DENSE FOG ADVISORY FOR
AMZ352-354 THROUGH EARLY TONIGHT AS THE FLOW BECOMES SOUTH/SW.
THIS WILL DIRECT THE FOG FURTHER NORTH INTO THE AMZ350
WATERS...MAYBE EVEN BRUSHING CHARLESTON HARBOR FOR A TIME...AND
ADDITIONAL DENSE FOG ADVISORIES MAY BE REQUIRED. WINDS/SEAS WILL
APPROACH SMALL CRAFT ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...





000
FXUS62 KCHS 261124
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
724 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...MORNING LOW CLOUDS/FOG WILL CLEAR BY 9 OR 10 AM...EXCEPT
POSSIBLY LINGERING NEAR THE COAST MUCH IF NOT ALL OF THE DAY. SOME
OF THE FOG COULD BE DENSE BUT WE DO NOT THINK IT WILL BE
WIDESPREAD ENOUGH TO WARRANT AN ADVISORY GIVEN SOME MIXING FROM
THE LOW-LEVEL JET. PROBABLY THE BEST RISK FOR DENSE FOG WILL COME
FROM ANY SEA FOG THAT DEVELOPS OVER THE NEARBY ATLANTIC AND PUSHES
INLAND.

THE AREA WILL BECOME INCREASINGLY IN THE WARM SECTOR AHEAD OF AN
APPROACHING COLD FRONT. AS THE LOW LEVEL FLOW VEERS TO
SOUTH/SOUTHWEST THE SHOWERS ACROSS THE ATLANTIC THIS MORNING WILL
REMAIN OFFSHORE. IT WILL THEN REMAIN DRY UNTIL LATE AFTERNOON
WHEN DEEP MOISTURE BEGINS TO ADVECT BACK IN FROM THE SOUTHWEST AND
A RESULTANT SEA BREEZE DEVELOPS. THUS...RAIN CHANCES WILL BE ON
THE INCREASE FROM THE SOUTH WITH THE POTENTIAL FOR SOME WEAK
THUNDERSTORMS TOWARD LATE AFTERNOON...MAINLY OVER SOUTHEAST
GEORGIA. HIGHS SHOULD PUSH INTO THE LOWER 80S MOST PLACES INLAND
AWAY FROM THE COOLER COASTAL AREAS.

TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
KCHS...IFR/LIFR CONDITIONS THROUGH 14Z WILL GIVE WAY TO A RETURN
OF VFR WEATHER FOR THE BALANCE OF THE DAY AS INVERSION WEAKENS AND
LIFTS HIGHER. SOUTH/SW WINDS WILL BE GUSTY DURING THE AFTERNOON AS
UNSEASONABLY TEMPS PREVAIL IN ADVANCE OF A COLD FRONT...WHILE
ENHANCEMENT ALSO OCCURS FROM SEA BREEZE INFLUENCES. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH THE OPTION FOR ADJUSTMENTS AT A LATER TIME.

KSAV...A SHARP INVERSION WILL KEEP THE AIRFIELD LOCKED IN WITH
LIFR CONDITIONS AND NEAR AIRPORT MINIMUMS THROUGH 14Z...BEFORE
IMPROVING BACK TO VFR BY 15Z AS THE INVERSION BREAKS AND MOISTURE
SCOURS OUT. GUSTY SOUTH/SW WINDS WILL THEN PREVAIL FOR THE
HEATING OF THE AFTERNOON IN ADVANCE OF A COLD FRONT...WITH
ADDITIONAL IMPETUS FROM THE SEA BREEZE. CONDITIONS AT
SOME POINT TONIGHT MAY LOWER INTO THE MVFR RANGE AS SHOWERS
DEVELOP IN RESPONSE TO A SHORT WAVE ARRIVING FROM THE GULF AND THE
COLD FRONT APPROACHES FROM THE WEST/NW. UNTIL TRENDS CAN BE BETTER
DEFINED WE HAVE KEPT VFR CONDITIONS GOING THROUGH 12Z
FRIDAY...WITH FUTURE ADJUSTMENTS LIKELY.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY AND TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD
FRONT LATE TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE
CREATING A GOOD ENVIRONMENT FOR SEA FOG. BASED ON REPORTS FROM THE
PORT OF SAVANNAH...WEBCAMS...COASTAL OBSERVATIONAL SITES AND
GOES-E PRODUCTS WE HAVE RAISED A DENSE FOG ADVISORY FOR
AMZ352-354 THROUGH EARLY TONIGHT AS THE FLOW BECOMES SOUTH/SW.
THIS WILL DIRECT THE FOG FURTHER NORTH INTO THE AMZ350
WATERS...MAYBE EVEN BRUSHING CHARLESTON HARBOR FOR A TIME...AND
ADDITIONAL DENSE FOG ADVISORIES MAY BE REQUIRED. WINDS/SEAS WILL
APPROACH SMALL CRAFT ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS62 KCHS 261045
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
645 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...MORNING LOW CLOUDS/FOG WILL CLEAR BY 9 OR 10 AM...EXCEPT
POSSIBLY LINGERING NEAR THE COAST MUCH IF NOT ALL OF THE DAY. SOME
OF THE FOG COULD BE DENSE BUT WE DO NOT THINK IT WILL BE
WIDESPREAD ENOUGH TO WARRANT AN ADVISORY GIVEN SOME MIXING FROM
THE LOW-LEVEL JET. PROBABLY THE BEST RISK FOR DENSE FOG WILL COME
FROM ANY SEA FOG THAT DEVELOPS OVER THE NEARBY ATLANTIC AND PUSHES
INLAND.

THE AREA WILL BECOME INCREASINGLY IN THE WARM SECTOR AHEAD OF AN
APPROACHING COLD FRONT. AS THE LOW LEVEL FLOW VEERS TO
SOUTH/SOUTHWEST THE SHOWERS ACROSS THE ATLANTIC THIS MORNING WILL
REMAIN OFFSHORE. IT WILL THEN REMAIN DRY UNTIL LATE AFTERNOON
WHEN DEEP MOISTURE BEGINS TO ADVECT BACK IN FROM THE SOUTHWEST AND
A RESULTANT SEA BREEZE DEVELOPS. THUS...RAIN CHANCES WILL BE ON
THE INCREASE FROM THE SOUTH WITH THE POTENTIAL FOR SOME WEAK
THUNDERSTORMS TOWARD LATE AFTERNOON...MAINLY OVER SOUTHEAST
GEORGIA. HIGHS SHOULD PUSH INTO THE LOWER 80S MOST PLACES INLAND
AWAY FROM THE COOLER COASTAL AREAS.

TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW CLOUDS AND SOME FOG THROUGH ABOUT 13Z WITH PRETTY QUICK
IMPROVEMENT THEREAFTER. EXPECT THE WORST CONDS AT KSAV WITH LIFR
CIGS...POSSIBLY AT KCHS AS WELL BUT LESS LIKELY. VSBYS SHOULD
GO NO LOWER THAN MVFR AT KCHS BUT IFR IS POSSIBLE...WHILE AT KSAV
IFR VSBYS ARE EXPECTED...POSSIBLY DROPPING TO LIFR.

LOW CLOUDS AND FOG WILL GIVE WAY TO VFR CONDITIONS BY ABOUT 14Z AS
DRIER LOW LEVEL AIR MOVES IN FROM THE SOUTHWEST. LOW CLOUDS/SHOWER
CHANCES WILL BE INCREASING LATE IN THE AFTERNOON AT KSAV AND THEN
AT KCHS EARLY IN THE EVENING BUT WITH SOME TIMING UNCERTAINTY
REMAINING WE WILL KEEP TAFS VFR.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY AND TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD
FRONT LATE TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE
CREATING A GOOD ENVIRONMENT FOR SEA FOG. BASED ON REPORTS FROM THE
PORT OF SAVANNAH...WEBCAMS...COASTAL OBSERVATIONAL SITES AND
GOES-E PRODUCTS WE HAVE RAISED A DENSE FOG ADVISORY FOR
AMZ352-354 THROUGH EARLY TONIGHT AS THE FLOW BECOMES SOUTH/SW.
THIS WILL DIRECT THE FOG FURTHER NORTH INTO THE AMZ350
WATERS...MAYBE EVEN BRUSHING CHARLESTON HARBOR FOR A TIME...AND
ADDITIONAL DENSE FOG ADVISORIES MAY BE REQUIRED. WINDS/SEAS WILL
APPROACH SMALL CRAFT ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS62 KCHS 261045
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
645 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...MORNING LOW CLOUDS/FOG WILL CLEAR BY 9 OR 10 AM...EXCEPT
POSSIBLY LINGERING NEAR THE COAST MUCH IF NOT ALL OF THE DAY. SOME
OF THE FOG COULD BE DENSE BUT WE DO NOT THINK IT WILL BE
WIDESPREAD ENOUGH TO WARRANT AN ADVISORY GIVEN SOME MIXING FROM
THE LOW-LEVEL JET. PROBABLY THE BEST RISK FOR DENSE FOG WILL COME
FROM ANY SEA FOG THAT DEVELOPS OVER THE NEARBY ATLANTIC AND PUSHES
INLAND.

THE AREA WILL BECOME INCREASINGLY IN THE WARM SECTOR AHEAD OF AN
APPROACHING COLD FRONT. AS THE LOW LEVEL FLOW VEERS TO
SOUTH/SOUTHWEST THE SHOWERS ACROSS THE ATLANTIC THIS MORNING WILL
REMAIN OFFSHORE. IT WILL THEN REMAIN DRY UNTIL LATE AFTERNOON
WHEN DEEP MOISTURE BEGINS TO ADVECT BACK IN FROM THE SOUTHWEST AND
A RESULTANT SEA BREEZE DEVELOPS. THUS...RAIN CHANCES WILL BE ON
THE INCREASE FROM THE SOUTH WITH THE POTENTIAL FOR SOME WEAK
THUNDERSTORMS TOWARD LATE AFTERNOON...MAINLY OVER SOUTHEAST
GEORGIA. HIGHS SHOULD PUSH INTO THE LOWER 80S MOST PLACES INLAND
AWAY FROM THE COOLER COASTAL AREAS.

TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW CLOUDS AND SOME FOG THROUGH ABOUT 13Z WITH PRETTY QUICK
IMPROVEMENT THEREAFTER. EXPECT THE WORST CONDS AT KSAV WITH LIFR
CIGS...POSSIBLY AT KCHS AS WELL BUT LESS LIKELY. VSBYS SHOULD
GO NO LOWER THAN MVFR AT KCHS BUT IFR IS POSSIBLE...WHILE AT KSAV
IFR VSBYS ARE EXPECTED...POSSIBLY DROPPING TO LIFR.

LOW CLOUDS AND FOG WILL GIVE WAY TO VFR CONDITIONS BY ABOUT 14Z AS
DRIER LOW LEVEL AIR MOVES IN FROM THE SOUTHWEST. LOW CLOUDS/SHOWER
CHANCES WILL BE INCREASING LATE IN THE AFTERNOON AT KSAV AND THEN
AT KCHS EARLY IN THE EVENING BUT WITH SOME TIMING UNCERTAINTY
REMAINING WE WILL KEEP TAFS VFR.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY AND TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD
FRONT LATE TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE
CREATING A GOOD ENVIRONMENT FOR SEA FOG. BASED ON REPORTS FROM THE
PORT OF SAVANNAH...WEBCAMS...COASTAL OBSERVATIONAL SITES AND
GOES-E PRODUCTS WE HAVE RAISED A DENSE FOG ADVISORY FOR
AMZ352-354 THROUGH EARLY TONIGHT AS THE FLOW BECOMES SOUTH/SW.
THIS WILL DIRECT THE FOG FURTHER NORTH INTO THE AMZ350
WATERS...MAYBE EVEN BRUSHING CHARLESTON HARBOR FOR A TIME...AND
ADDITIONAL DENSE FOG ADVISORIES MAY BE REQUIRED. WINDS/SEAS WILL
APPROACH SMALL CRAFT ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...





000
FXUS62 KCHS 261045
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
645 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...MORNING LOW CLOUDS/FOG WILL CLEAR BY 9 OR 10 AM...EXCEPT
POSSIBLY LINGERING NEAR THE COAST MUCH IF NOT ALL OF THE DAY. SOME
OF THE FOG COULD BE DENSE BUT WE DO NOT THINK IT WILL BE
WIDESPREAD ENOUGH TO WARRANT AN ADVISORY GIVEN SOME MIXING FROM
THE LOW-LEVEL JET. PROBABLY THE BEST RISK FOR DENSE FOG WILL COME
FROM ANY SEA FOG THAT DEVELOPS OVER THE NEARBY ATLANTIC AND PUSHES
INLAND.

THE AREA WILL BECOME INCREASINGLY IN THE WARM SECTOR AHEAD OF AN
APPROACHING COLD FRONT. AS THE LOW LEVEL FLOW VEERS TO
SOUTH/SOUTHWEST THE SHOWERS ACROSS THE ATLANTIC THIS MORNING WILL
REMAIN OFFSHORE. IT WILL THEN REMAIN DRY UNTIL LATE AFTERNOON
WHEN DEEP MOISTURE BEGINS TO ADVECT BACK IN FROM THE SOUTHWEST AND
A RESULTANT SEA BREEZE DEVELOPS. THUS...RAIN CHANCES WILL BE ON
THE INCREASE FROM THE SOUTH WITH THE POTENTIAL FOR SOME WEAK
THUNDERSTORMS TOWARD LATE AFTERNOON...MAINLY OVER SOUTHEAST
GEORGIA. HIGHS SHOULD PUSH INTO THE LOWER 80S MOST PLACES INLAND
AWAY FROM THE COOLER COASTAL AREAS.

TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW CLOUDS AND SOME FOG THROUGH ABOUT 13Z WITH PRETTY QUICK
IMPROVEMENT THEREAFTER. EXPECT THE WORST CONDS AT KSAV WITH LIFR
CIGS...POSSIBLY AT KCHS AS WELL BUT LESS LIKELY. VSBYS SHOULD
GO NO LOWER THAN MVFR AT KCHS BUT IFR IS POSSIBLE...WHILE AT KSAV
IFR VSBYS ARE EXPECTED...POSSIBLY DROPPING TO LIFR.

LOW CLOUDS AND FOG WILL GIVE WAY TO VFR CONDITIONS BY ABOUT 14Z AS
DRIER LOW LEVEL AIR MOVES IN FROM THE SOUTHWEST. LOW CLOUDS/SHOWER
CHANCES WILL BE INCREASING LATE IN THE AFTERNOON AT KSAV AND THEN
AT KCHS EARLY IN THE EVENING BUT WITH SOME TIMING UNCERTAINTY
REMAINING WE WILL KEEP TAFS VFR.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY AND TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD
FRONT LATE TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE
CREATING A GOOD ENVIRONMENT FOR SEA FOG. BASED ON REPORTS FROM THE
PORT OF SAVANNAH...WEBCAMS...COASTAL OBSERVATIONAL SITES AND
GOES-E PRODUCTS WE HAVE RAISED A DENSE FOG ADVISORY FOR
AMZ352-354 THROUGH EARLY TONIGHT AS THE FLOW BECOMES SOUTH/SW.
THIS WILL DIRECT THE FOG FURTHER NORTH INTO THE AMZ350
WATERS...MAYBE EVEN BRUSHING CHARLESTON HARBOR FOR A TIME...AND
ADDITIONAL DENSE FOG ADVISORIES MAY BE REQUIRED. WINDS/SEAS WILL
APPROACH SMALL CRAFT ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...




000
FXUS62 KCHS 261045
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
645 AM EDT THU MAR 26 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL WEAKEN AHEAD OF A STRONG COLD FRONT
APPROACHING TONIGHT AND SWEEPING THROUGH DURING FRIDAY. COLDER HIGH
PRESSURE WILL THEN BUILD FOR THE WEEKEND...SUPPORTING A POSSIBLE
FREEZE FOR SOME INLAND AREAS EARLY SUNDAY. HIGH PRESSURE THEN SHIFTS
SOUTH OF THE REGION MONDAY...BEFORE ANOTHER COLD FRONT MOVES
THROUGH LATE MONDAY OR EARLY TUESDAY. HIGH PRESSURE WILL THEN
PREVAIL INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...MORNING LOW CLOUDS/FOG WILL CLEAR BY 9 OR 10 AM...EXCEPT
POSSIBLY LINGERING NEAR THE COAST MUCH IF NOT ALL OF THE DAY. SOME
OF THE FOG COULD BE DENSE BUT WE DO NOT THINK IT WILL BE
WIDESPREAD ENOUGH TO WARRANT AN ADVISORY GIVEN SOME MIXING FROM
THE LOW-LEVEL JET. PROBABLY THE BEST RISK FOR DENSE FOG WILL COME
FROM ANY SEA FOG THAT DEVELOPS OVER THE NEARBY ATLANTIC AND PUSHES
INLAND.

THE AREA WILL BECOME INCREASINGLY IN THE WARM SECTOR AHEAD OF AN
APPROACHING COLD FRONT. AS THE LOW LEVEL FLOW VEERS TO
SOUTH/SOUTHWEST THE SHOWERS ACROSS THE ATLANTIC THIS MORNING WILL
REMAIN OFFSHORE. IT WILL THEN REMAIN DRY UNTIL LATE AFTERNOON
WHEN DEEP MOISTURE BEGINS TO ADVECT BACK IN FROM THE SOUTHWEST AND
A RESULTANT SEA BREEZE DEVELOPS. THUS...RAIN CHANCES WILL BE ON
THE INCREASE FROM THE SOUTH WITH THE POTENTIAL FOR SOME WEAK
THUNDERSTORMS TOWARD LATE AFTERNOON...MAINLY OVER SOUTHEAST
GEORGIA. HIGHS SHOULD PUSH INTO THE LOWER 80S MOST PLACES INLAND
AWAY FROM THE COOLER COASTAL AREAS.

TONIGHT...RAIN CHANCES INCREASE AS THE FRONT APPROACHES FROM THE
WEST AND LARGE SCALE LIFT/DEEP MOISTURE MOVE INTO THE AREA.
INSTABILITY APPEARS WEAK BUT CANNOT RULE OUT A FEW THUNDERSTORMS
GIVEN THE INCREASING LOW-LEVEL JET/DEEP LAYER SHEAR. GIVEN THE
WARM AND HUMID AIR MASS ADVECTING INTO THE AREA THERE MIGHT STILL
BE SOME SEA FOG NEAR THE COAST...ESPECIALLY UNTIL WINDS BECOME
MORE SOUTHWEST AFTER MIDNIGHT. TEMPS WILL LIKELY NOT DROP BELOW
60 DEGREES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY...A DEEPENING AND AMPLIFYING LONG WAVE TROUGH WILL PREVAIL
OVER THE EASTERN STATES...WITH SOME PHASING OF A SHORT WAVE OVER THE
LOWER MS VALLEY WITH ANOTHER AND STRONGER SHORT WAVE THAT DIVES FROM
THE MID MS VALLEY INTO THE TN VALLEY IN THE AFTERNOON. THIS
TRANSITION WILL CAUSE HEIGHTS ALOFT TO STEADILY FALL AND WILL SHOVE
A STRONG COLD FRONT INTO THE NW TIER DURING THE MID-LATE
MORNING...TOWARD OUR COASTAL CORRIDOR BY EARLY AFTERNOON...AND INTO
THE ATLANTIC THEREAFTER. LOW LEVEL CONVERGENCE WILL COMBINE WITH
LARGER SCALE FORCING FOR ASCENT DUE TO STRONG VERTICAL WIND FIELDS
THROUGHOUT THE TROPOSPHERE...MOST NOTABLY A 30-40 KT LOW LEVEL JET
AND A 130-150 UPPER JET. THESE DYNAMICS WILL HAVE CONSIDERABLE
MOISTURE TO WORK WITH...AS PWATS ARE AS MUCH AS 1-2 STANDARD
DEVIATIONS ABOVE NORMAL FOR LATE MARCH. THIS WILL RESULT IN AT
LEAST 60-70 POPS MAINLY IN THE FORM OF SHOWERS. HOWEVER...GIVEN 50-
60 KT OF BULK SHEAR AND SBCAPES THAT COULD BE AS GREAT AS 300-500
J/KG THERE CERTAINLY COULD BE A FEW RUMBLES OF THUNDER. RAIN CHANCES
WILL PEAK IN THE MORNING...THEN TAIL OFF FROM WEST TO EAST IN THE
AFTERNOON.

WARM ADVECTION IN ADVANCE OF THE COLD FRONT WILL ASSIST IN NEGATING
THE LACK OF INSOLATION...BUT FRIDAY WILL CERTAINLY BE NOTICEABLY
COOLER THAN IT WILL BE TODAY. IN FACT AS COLD ADVECTION ARRIVES IN
THE AFTERNOON THERE COULD ACTUALLY BE SOME SLOW FALL TO SOME OF OUR
TEMPS THE REST OF THE DAY.

FRIDAY NIGHT...ALTHOUGH THE DEEP MOISTURE WILL HAVE PULLED EAST WITH
THE COLD FRONT...THERE IS STILL SOME LINGERING LOW LEVEL MOISTURE
WITHIN THE FIRST COUPLE OF MILES OFF THE DECK. A POTENT SHORT WAVE
EMBEDDED WITHIN THE LONG WAVE TROUGH ALOFT WILL MOVE DIRECTLY
THROUGH THE CWFA AROUND 05-08Z. THIS WILL SUPPORT 20-30 POPS AND
MAINLY ACROSS THE CHARLESTON TRI-COUNTY REGION WHERE THE BEST
MOISTURE WILL REMAIN. ALTHOUGH COLDER AIR WILL BE FILTERING IN...AS
PER SOUNDING PROFILES IT LOOKS LIKE ONE OF THOSE EVENTS WHERE THE
COLD AIR IS TRYING TO CATCH UP TO THE DEPARTING MOISTURE AND IT WILL
ARRIVE TOO LATE TO PRODUCE ANYTHING OTHER THAN LIQUID. BUT DUE TO
THE STEEP MID LEVEL LAPSE RATES WHERE 500 MB TEMPS ARE NEAR MINUS
27C...THERE APPEARS TO BE A RISK FOR SOME GRAUPEL OR SOFT HAIL. 850
MB TEMPS WILL PLUNGE TO -3C SOUTH AND -6C NORTH...SUPPORTIVE OF
LOWEST TEMPS IN THE MID 30S TO LOWER 40S. BUT THERE IS TOO MUCH WIND
AND THE GROUNDS ARE TOO WET FOR ANY FROST.

SATURDAY...THE LARGE SCALE EAST COAST TROUGH REMAINS IN
PLACE...WHILE SIMULTANEOUSLY SURFACE HIGH PRESSURE GRADUALLY BUILDS
FROM THE WEST/NW. ANOTHER SHORT WAVE EMBEDDED WITHIN THE DEEP NW
FLOW WILL DROP THROUGH THE UPPER MIDWEST TO NEAR THE SOUTHERN
APPALACHIANS LATE. THIS WILL RESULT IN AN INCREASE IN MID/HIGH LEVEL
CLOUDS OVER THE SW PART OF THE CWFA. ALTHOUGH THERE IS DECENT
INSOLATION...WITH 850 MB TEMPS CLOSE TO 2 STANDARD DEVIATIONS BELOW
NORMAL WE/LL BE HARD PRESSED TO REACH AN MORE THAN 55-60F.

SATURDAY NIGHT...THE AFOREMENTIONED SHORT WAVE WILL PULL THROUGH
OVERNIGHT AND USHER IN A 1033 ARCTIC HIGH FROM THE OHIO VALLEY. THE
ASSOCIATED COLD ADVECTION WILL RESULT IN UNSEASONABLY COLD AIR
PENETRATING INTO THE BULK OF THE FORECAST DISTRICT. THERE LOOKS TO
BE TOO MUCH MIXING TO PREVENT A HARD FREEZE...BUT A LIGHT FREEZE IS
CERTAINLY POSSIBLE ACROSS AT LEAST THE NW TIER. IF WINDS DO DROP OFF
ENOUGH THEN TEMPS COULD BE EVEN COLDER THAN 30-32F IN THESE SECTIONS
AND FROST WOULD ALSO BE A CONCERN IN MANY OTHER COMMUNITIES SOUTH
AND EAST.

SUNDAY...THE EAST COAST TROUGH LIFTS OUT AND GIVES WAY TO SHORT WAVE
RIDGING AND ITS ASSOCIATED RISING HEIGHTS...AS THE CORE OF THE
ARCTIC HIGH SHIFTS DIRECTLY OVERHEAD. DESPITE PLENTIFUL SUNSHINE AND
THE AIR MASS MODIFYING...TEMPS WILL ONLY BE ABLE TO MUSTER THE UPPER
50S AND LOWER 60S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MID LEVEL PATTERN WILL FLATTEN THROUGH THE EARLY AND MIDDLE
PARTS OF NEXT WEEK...ALTHOUGH A SUBTLE IMPULSE WILL MOVE THROUGH
LATE MONDAY/EARLY TUESDAY. THIS WILL FORCE A COLD FRONT THROUGH THE
FORECAST ZONES...ACCOMPANYING ONLY BY MODEST MOISTURE AND JUST
LIMITED CHANCES FOR SHOWERS. THE FRONT THEN WASHES OUT AND GIVES WAY
TO HIGH PRESSURE THROUGH MID WEEK. WARMER CONDITIONS WILL RETURN AS
EVEN THE AIR MASS BEHIND THE COLD FRONT IS OF PACIFIC ORIGIN SO
TEMPS SHOULD GET BACK NEAR OR EVEN ABOVE SEASONAL NORMS.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW CLOUDS AND SOME FOG THROUGH ABOUT 13Z WITH PRETTY QUICK
IMPROVEMENT THEREAFTER. EXPECT THE WORST CONDS AT KSAV WITH LIFR
CIGS...POSSIBLY AT KCHS AS WELL BUT LESS LIKELY. VSBYS SHOULD
GO NO LOWER THAN MVFR AT KCHS BUT IFR IS POSSIBLE...WHILE AT KSAV
IFR VSBYS ARE EXPECTED...POSSIBLY DROPPING TO LIFR.

LOW CLOUDS AND FOG WILL GIVE WAY TO VFR CONDITIONS BY ABOUT 14Z AS
DRIER LOW LEVEL AIR MOVES IN FROM THE SOUTHWEST. LOW CLOUDS/SHOWER
CHANCES WILL BE INCREASING LATE IN THE AFTERNOON AT KSAV AND THEN
AT KCHS EARLY IN THE EVENING BUT WITH SOME TIMING UNCERTAINTY
REMAINING WE WILL KEEP TAFS VFR.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY FRIDAY IN
ASSOCIATION WITH SCATTERED TO NUMEROUS SHRA AND POSSIBLE TSRA AS A
COLD FRONT MOVES THROUGH. VFR WEATHER WILL THEN PREVAIL LATE FRIDAY
INTO MONDAY...WITH POSSIBLE SUB-VFR WEATHER WITH ANOTHER COLD FRONT
LATE MONDAY.

&&

.MARINE...
TODAY AND TONIGHT...VEERING WINDS AHEAD OF AN APPROACHING COLD
FRONT LATE TONIGHT. WARM AND MOIST AIR MASS WILL REMAIN IN PLACE
CREATING A GOOD ENVIRONMENT FOR SEA FOG. BASED ON REPORTS FROM THE
PORT OF SAVANNAH...WEBCAMS...COASTAL OBSERVATIONAL SITES AND
GOES-E PRODUCTS WE HAVE RAISED A DENSE FOG ADVISORY FOR
AMZ352-354 THROUGH EARLY TONIGHT AS THE FLOW BECOMES SOUTH/SW.
THIS WILL DIRECT THE FOG FURTHER NORTH INTO THE AMZ350
WATERS...MAYBE EVEN BRUSHING CHARLESTON HARBOR FOR A TIME...AND
ADDITIONAL DENSE FOG ADVISORIES MAY BE REQUIRED. WINDS/SEAS WILL
APPROACH SMALL CRAFT ADVISORY LEVELS LATE TONIGHT BEYOND 20 NM.

FRIDAY...A FAIRLY TIGHT AND CYCLONIC SW PRESSURE PATTERN WILL
PREVAIL IN ADVANCE OF THE COLD FRONT THAT DOESN/T MOVE THROUGH AFTER
1 OR 2 PM. WARM ADVECTION WILL RESTRICT THE AMOUNT OF MIXING...BUT
GIVEN GEOSTROPHIC WINDS OF 30 KT OR SO THIS WILL SUPPORT MARGINAL
SMALL CRAFT ADVISORIES ACROSS THE AMZ374 WATERS FOR GUSTS UP NEAR 25
KT AND SEAS AS HIGH AS 6 FT. WE STILL MIGHT NEED TO EXPAND THE
ADVISORY TO ENCOMPASS AMZ350...BUT FOR NOW THOSE WATERS LOOK TO
REMAIN JUST BELOW ANY ADVISORY CONDITIONS. EVEN THOUGH WIND FIELDS
WILL BE SOMEWHAT ELEVATED...SEA FOG WILL CONTINUE UNTIL THE FRONT
SCOURS THINGS OUT AND VISIBILITIES IMPROVE. MARINERS SHOULD ALSO
REMAIN ALERT FOR POSSIBLE T-STORMS...MOST ESPECIALLY ACROSS THE GULF
STREAM WATERS.

FRIDAY NIGHT AND SATURDAY...A MIXTURE OF COLD ADVECTION AND GOOD
ISALLOBARIC PRESSURE RISES WILL LIKELY SUPPORT ADDITIONAL SMALL
CRAFT ADVISORIES AS NW WINDS APPROACH 20-25 KT IN WAKE OF THE COLD
FRONT AND STRENGTHENING ATLANTIC LOW PRESSURE SOUTH/SE OF NEW ENGLAND.

SATURDAY NIGHT AND SUNDAY...STRONG CONTINENTAL HIGH PRESSURE WILL
BUILD FROM THE NW AND WILL BE ACCOMPANIED BY A SURGE OF NORTH/NE
WINDS AROUND DAYBREAK SUNDAY...BUT LIKELY BENEATH ANY ADVISORY
CRITERIA. THE HIGH WILL THEN SETTLE ATOP THE WATERS BY LATE IN THE
DAY AND WINDS AND SEAS WILL COME DOWN.

MONDAY AND TUESDAY...HIGH PRESSURE EARLY NEXT WEEK WILL GIVE WAY TO
A COLD FRONT THAT MOVES THROUGH BY EARLY TUESDAY...BEFORE BECOMING
DIFFUSE. MARINE CONDITIONS WILL BE AT OR LESS THAN 15 OR 20 KT FOR
WINDS AND LESS THAN 3-5 FOOT SEAS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ352-354.
     SMALL CRAFT ADVISORY FROM 6 AM FRIDAY TO 1 PM EDT SATURDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...





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