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000
FXUS62 KCHS 220302
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1002 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM...BUT GIVEN CONSIDERABLE
RAINS EARLY ON THIS WILL ACT TO SHUNT ANY RELAXATION OF THE GRIP
OF THE WEDGE BACK TO THE SOUTH. THE COASTAL WARM FRONT WILL
ATTEMPT TO SWING TOWARD THE COAST BEFORE THE WAVE LIFTS OFF TO THE
NE LATE.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE ACROSS THE LOCAL AREA.

FIRST BATCH OF RAIN WILL LIFT NORTH OF THE SAVANNAH RIVER LATE
THIS EVENING...COVERING MOST OF OUR SC ZONES. THIS IS IN RESPONSE
TO THE SHORT WAVE RIDING NE FROM OUT OF THE GULF OF MEXICO AND
CONSIDERABLE ISENTROPIC LIFT. THERE IS STEADY PROGRESSION OF THIS
ACTIVITY AND MUCH OF IT WILL BE NORTH/NE OF THE SANTEE RIVER AND
OFFSHORE IN THE ATLANTIC BY 1 OR 2 AM. HOWEVER...ANOTHER SHORT
WAVE NEAR THE FLORIDA PANHANDLE AND ANOTHER DOSE OF ISENTROPIC
ASCENT LATE COULD AGAIN CAUSE ADDITIONAL RAINS TO BREAK OUT FROM
SW TO NE. COMBINED WITH LARGE FORCING FROM THE RIGHT ENTRANCE
REGION OF THE 125 KT UPPER JET...WE ARE CARRYING CATEGORICAL POPS
ACROSS MOST OF SC EARLY ON...WITH CHANCE TO LIKELY CHANCES
SOUTH...THEN CHANCE TO LIKELY ALL SECTIONS LATE. THERE CONTINUES
TO BE AN OCCASIONAL LIGHTNING STRIKE HERE OR THERE WITH STEEP MID
LEVEL LAPSE RATES AND MU CAPES OF 100-200 J/KG...AND THIS WILL
CONTINUE FOR A FEW MORE HOURS.

PWATS OF 1.3-1.5 INCHES WILL ALLOW FOR LIGHT TO MODERATE RAINS AND
PRODUCE AS MUCH AS ANOTHER 1/4 TO 1/2 INCH RAINFALL THE REST OF
THE NIGHT.

WIDESPREAD LOW STRATUS CLOUD DECKS WILL LOWER FURTHER AND THIS
WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA WHERE
THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR. HOWEVER...WE
MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND NW WITH
LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF DENSE
FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF RAIN OR DRIZZLE.

KCHS...WHILE WE STILL HAVE LOW-END MVFR CONDITIONS EARLY ON...WITH
OVER-RUNNING RAINS TO RE-ENFORCE THE WEDGE INVERSION ATOP THE
TERMINAL...THIS WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE
OVERNIGHT AND THROUGH THE BALANCE OF THE PERIOD.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT IS STILL PINCHED LATE THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE EXTENDED THE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15-20 KT AND 1-2 FT WAVES. AS THE ATLANTIC WAVE
DROPS A COUPLE MILLIBARS AND GATHERS A CLOSED CIRCULATION
OVERNIGHT IT WILL LIFT NE. AS THIS OCCURS WE LOOK FOR A DROP IN
WINDS AND GRADUALLY ALSO IN THE SEAS TOO. LOW STRATUS AND PERIODS
OF RAIN WILL OCCASIONALLY DROP VISIBILITIES UNDER 2 OR 3 NM
THROUGH THE NIGHT. PLUS THERE CAN ALSO BE A LITTLE THUNDER AND
LIGHTNING IN A FEW TALLER CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY. COASTAL FLOOD ADVISORIES MAY BECOME
NECESSARY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR AMZ350-352.
     SMALL CRAFT ADVISORY UNTIL 1 AM EST MONDAY FOR AMZ354.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 220059
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
759 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM THIS EVENING...BUT GIVEN
CONSIDERABLE RAINS THIS WILL ACT TO SHUNT ANY RELAXATION OF THE
GRIP OF THE WEDGE BACK TO THE SOUTH.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE TOWARD THE LOCAL AREA.

SHORT WAVES EMBEDDED WITHIN THE SW FLOW UPSTAIRS WILL HEAD INTO
THE REGION LATER THIS EVENING AND OVERNIGHT...CAUSING WEAK
CYCLOGENESIS TO OCCUR OFF THE SE COAST NEAR THE GULF
STREAM...BEFORE IT TRIES TO DEVELOP SOME CLOSED ISOBARS BY
MORNING. THE PROXIMITY TO THIS FEATURE AND INCREASING ISENTROPIC
LIFT WILL FUEL THE EXPANSION OF LIGHT TO MODERATE RAINS TONIGHT.
THIS WILL BE AIDED FURTHER BY THE DYNAMICS OF THE SHORT WAVES ALOFT
AND LARGE SCALE FORCING FROM THE RIGHT REAR QUAD OF A 125 KT UPPER
JET. SUFFICE TO SAY WE/RE IN FOR MORE RAINFALL. WITH PWATS
CLIMBING TO 1.2 TO 1.4 INCHES WHICH IS WELL ABOVE LATE DECEMBER
NORMS...WE ANTICIPATE ON AVERAGE ABOUT 1/3 TO 2/3 INCHES OF RAIN.
IN ADDITION RECENT RADAR IS SHOWING SOME CONVECTIVE ELEMENTS
WITHIN THE INCREASING COVERAGE OF THE RAIN IS RESPONSE TO STEEP
MID LEVEL LAPSE RATES...THE DYNAMICS ALOFT AND SURPRISINGLY
MU CAPES CLOSE TO 200 J/KG. THIS COULD LEAD TO LOCALLY HIGHER
RAIN TOTALS...AS WELL AS POSSIBLE SOME THUNDER AND LIGHTNING.

LOW STRATUS AND STRATOCUMULUS CLOUD DECKS WILL LOWER FURTHER AND
THIS WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA
WHERE THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR.
HOWEVER...WE MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND
NW WITH LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF
DENSE FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF LIGHT TO MODERATE RAINS. THERE
ARE ACTUAL EVEN SOME CONVECTIVE ELEMENTS EMBEDDED WITHIN THE RAIN
SHIELD EARLY TONIGHT...BUT ANY DIRECT HIT FROM A TSRA AT THE
TERMINAL IS FAR TO LOW TO INCLUDE AT THIS TIME.

KCHS...WHILE WE BEGIN THE VALID 00Z CYCLE WITH MVFR
CONDITIONS...WITH OVER-RUNNING RAINS TO ARRIVE THROUGH THE NIGHT
IT WILL RE-ENFORCE THE WEDGE INVERSION ATOP THE TERMINAL. THIS
WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE OVERNIGHT AND
THROUGH THE BALANCE OF THE PERIOD. SIMILAR TO KSAV THERE IS A
MINUTE RISK OF TSRA LATER THIS EVENING AND OVERNIGHT. WE CONTINUE
TO KEEP A WATCH FOR MARGINAL LOW LEVEL WIND SHEAR AS WINDS AT 1-2K
FT ARE FORECAST TO BE EASTERLY AS HIGH AS 25-30 KT A LITTLE LATER
TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT HAS PINCHED FURTHER THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE CHOSEN TO RAISE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15 KT...BUT WINDS PICK UP TO AROUND 20 KT AND GUSTY
NEAR THE HARBOR ENTRANCE. AS THE ATLANTIC WAVE DROPS A COUPLE
MILLIBARS AND GATHERS A CLOSED CIRCULATION OVERNIGHT IT WILL LIFT
NE. AS THIS OCCURS WE LOOK FOR A DROP IN WINDS AND GRADUALLY ALSO
IN THE SEAS TOO. LOW STRATUS AND PERIODS OF RAIN WILL OCCASIONALLY
DROP VISIBILITIES UNDER 2 OR 3 NM THROUGH THE NIGHT. PLUS THERE
CAN ALSO BE A LITTLE THUNDER AND LIGHTNING IN A FEW TALLER
CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
     354.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...










000
FXUS62 KCHS 220059
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
759 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM THIS EVENING...BUT GIVEN
CONSIDERABLE RAINS THIS WILL ACT TO SHUNT ANY RELAXATION OF THE
GRIP OF THE WEDGE BACK TO THE SOUTH.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE TOWARD THE LOCAL AREA.

SHORT WAVES EMBEDDED WITHIN THE SW FLOW UPSTAIRS WILL HEAD INTO
THE REGION LATER THIS EVENING AND OVERNIGHT...CAUSING WEAK
CYCLOGENESIS TO OCCUR OFF THE SE COAST NEAR THE GULF
STREAM...BEFORE IT TRIES TO DEVELOP SOME CLOSED ISOBARS BY
MORNING. THE PROXIMITY TO THIS FEATURE AND INCREASING ISENTROPIC
LIFT WILL FUEL THE EXPANSION OF LIGHT TO MODERATE RAINS TONIGHT.
THIS WILL BE AIDED FURTHER BY THE DYNAMICS OF THE SHORT WAVES ALOFT
AND LARGE SCALE FORCING FROM THE RIGHT REAR QUAD OF A 125 KT UPPER
JET. SUFFICE TO SAY WE/RE IN FOR MORE RAINFALL. WITH PWATS
CLIMBING TO 1.2 TO 1.4 INCHES WHICH IS WELL ABOVE LATE DECEMBER
NORMS...WE ANTICIPATE ON AVERAGE ABOUT 1/3 TO 2/3 INCHES OF RAIN.
IN ADDITION RECENT RADAR IS SHOWING SOME CONVECTIVE ELEMENTS
WITHIN THE INCREASING COVERAGE OF THE RAIN IS RESPONSE TO STEEP
MID LEVEL LAPSE RATES...THE DYNAMICS ALOFT AND SURPRISINGLY
MU CAPES CLOSE TO 200 J/KG. THIS COULD LEAD TO LOCALLY HIGHER
RAIN TOTALS...AS WELL AS POSSIBLE SOME THUNDER AND LIGHTNING.

LOW STRATUS AND STRATOCUMULUS CLOUD DECKS WILL LOWER FURTHER AND
THIS WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA
WHERE THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR.
HOWEVER...WE MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND
NW WITH LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF
DENSE FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF LIGHT TO MODERATE RAINS. THERE
ARE ACTUAL EVEN SOME CONVECTIVE ELEMENTS EMBEDDED WITHIN THE RAIN
SHIELD EARLY TONIGHT...BUT ANY DIRECT HIT FROM A TSRA AT THE
TERMINAL IS FAR TO LOW TO INCLUDE AT THIS TIME.

KCHS...WHILE WE BEGIN THE VALID 00Z CYCLE WITH MVFR
CONDITIONS...WITH OVER-RUNNING RAINS TO ARRIVE THROUGH THE NIGHT
IT WILL RE-ENFORCE THE WEDGE INVERSION ATOP THE TERMINAL. THIS
WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE OVERNIGHT AND
THROUGH THE BALANCE OF THE PERIOD. SIMILAR TO KSAV THERE IS A
MINUTE RISK OF TSRA LATER THIS EVENING AND OVERNIGHT. WE CONTINUE
TO KEEP A WATCH FOR MARGINAL LOW LEVEL WIND SHEAR AS WINDS AT 1-2K
FT ARE FORECAST TO BE EASTERLY AS HIGH AS 25-30 KT A LITTLE LATER
TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT HAS PINCHED FURTHER THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE CHOSEN TO RAISE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15 KT...BUT WINDS PICK UP TO AROUND 20 KT AND GUSTY
NEAR THE HARBOR ENTRANCE. AS THE ATLANTIC WAVE DROPS A COUPLE
MILLIBARS AND GATHERS A CLOSED CIRCULATION OVERNIGHT IT WILL LIFT
NE. AS THIS OCCURS WE LOOK FOR A DROP IN WINDS AND GRADUALLY ALSO
IN THE SEAS TOO. LOW STRATUS AND PERIODS OF RAIN WILL OCCASIONALLY
DROP VISIBILITIES UNDER 2 OR 3 NM THROUGH THE NIGHT. PLUS THERE
CAN ALSO BE A LITTLE THUNDER AND LIGHTNING IN A FEW TALLER
CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
     354.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...










000
FXUS62 KCHS 220059
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
759 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM THIS EVENING...BUT GIVEN
CONSIDERABLE RAINS THIS WILL ACT TO SHUNT ANY RELAXATION OF THE
GRIP OF THE WEDGE BACK TO THE SOUTH.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE TOWARD THE LOCAL AREA.

SHORT WAVES EMBEDDED WITHIN THE SW FLOW UPSTAIRS WILL HEAD INTO
THE REGION LATER THIS EVENING AND OVERNIGHT...CAUSING WEAK
CYCLOGENESIS TO OCCUR OFF THE SE COAST NEAR THE GULF
STREAM...BEFORE IT TRIES TO DEVELOP SOME CLOSED ISOBARS BY
MORNING. THE PROXIMITY TO THIS FEATURE AND INCREASING ISENTROPIC
LIFT WILL FUEL THE EXPANSION OF LIGHT TO MODERATE RAINS TONIGHT.
THIS WILL BE AIDED FURTHER BY THE DYNAMICS OF THE SHORT WAVES ALOFT
AND LARGE SCALE FORCING FROM THE RIGHT REAR QUAD OF A 125 KT UPPER
JET. SUFFICE TO SAY WE/RE IN FOR MORE RAINFALL. WITH PWATS
CLIMBING TO 1.2 TO 1.4 INCHES WHICH IS WELL ABOVE LATE DECEMBER
NORMS...WE ANTICIPATE ON AVERAGE ABOUT 1/3 TO 2/3 INCHES OF RAIN.
IN ADDITION RECENT RADAR IS SHOWING SOME CONVECTIVE ELEMENTS
WITHIN THE INCREASING COVERAGE OF THE RAIN IS RESPONSE TO STEEP
MID LEVEL LAPSE RATES...THE DYNAMICS ALOFT AND SURPRISINGLY
MU CAPES CLOSE TO 200 J/KG. THIS COULD LEAD TO LOCALLY HIGHER
RAIN TOTALS...AS WELL AS POSSIBLE SOME THUNDER AND LIGHTNING.

LOW STRATUS AND STRATOCUMULUS CLOUD DECKS WILL LOWER FURTHER AND
THIS WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA
WHERE THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR.
HOWEVER...WE MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND
NW WITH LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF
DENSE FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF LIGHT TO MODERATE RAINS. THERE
ARE ACTUAL EVEN SOME CONVECTIVE ELEMENTS EMBEDDED WITHIN THE RAIN
SHIELD EARLY TONIGHT...BUT ANY DIRECT HIT FROM A TSRA AT THE
TERMINAL IS FAR TO LOW TO INCLUDE AT THIS TIME.

KCHS...WHILE WE BEGIN THE VALID 00Z CYCLE WITH MVFR
CONDITIONS...WITH OVER-RUNNING RAINS TO ARRIVE THROUGH THE NIGHT
IT WILL RE-ENFORCE THE WEDGE INVERSION ATOP THE TERMINAL. THIS
WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE OVERNIGHT AND
THROUGH THE BALANCE OF THE PERIOD. SIMILAR TO KSAV THERE IS A
MINUTE RISK OF TSRA LATER THIS EVENING AND OVERNIGHT. WE CONTINUE
TO KEEP A WATCH FOR MARGINAL LOW LEVEL WIND SHEAR AS WINDS AT 1-2K
FT ARE FORECAST TO BE EASTERLY AS HIGH AS 25-30 KT A LITTLE LATER
TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT HAS PINCHED FURTHER THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE CHOSEN TO RAISE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15 KT...BUT WINDS PICK UP TO AROUND 20 KT AND GUSTY
NEAR THE HARBOR ENTRANCE. AS THE ATLANTIC WAVE DROPS A COUPLE
MILLIBARS AND GATHERS A CLOSED CIRCULATION OVERNIGHT IT WILL LIFT
NE. AS THIS OCCURS WE LOOK FOR A DROP IN WINDS AND GRADUALLY ALSO
IN THE SEAS TOO. LOW STRATUS AND PERIODS OF RAIN WILL OCCASIONALLY
DROP VISIBILITIES UNDER 2 OR 3 NM THROUGH THE NIGHT. PLUS THERE
CAN ALSO BE A LITTLE THUNDER AND LIGHTNING IN A FEW TALLER
CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
     354.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...











000
FXUS62 KCHS 220059
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
759 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM THIS EVENING...BUT GIVEN
CONSIDERABLE RAINS THIS WILL ACT TO SHUNT ANY RELAXATION OF THE
GRIP OF THE WEDGE BACK TO THE SOUTH.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE TOWARD THE LOCAL AREA.

SHORT WAVES EMBEDDED WITHIN THE SW FLOW UPSTAIRS WILL HEAD INTO
THE REGION LATER THIS EVENING AND OVERNIGHT...CAUSING WEAK
CYCLOGENESIS TO OCCUR OFF THE SE COAST NEAR THE GULF
STREAM...BEFORE IT TRIES TO DEVELOP SOME CLOSED ISOBARS BY
MORNING. THE PROXIMITY TO THIS FEATURE AND INCREASING ISENTROPIC
LIFT WILL FUEL THE EXPANSION OF LIGHT TO MODERATE RAINS TONIGHT.
THIS WILL BE AIDED FURTHER BY THE DYNAMICS OF THE SHORT WAVES ALOFT
AND LARGE SCALE FORCING FROM THE RIGHT REAR QUAD OF A 125 KT UPPER
JET. SUFFICE TO SAY WE/RE IN FOR MORE RAINFALL. WITH PWATS
CLIMBING TO 1.2 TO 1.4 INCHES WHICH IS WELL ABOVE LATE DECEMBER
NORMS...WE ANTICIPATE ON AVERAGE ABOUT 1/3 TO 2/3 INCHES OF RAIN.
IN ADDITION RECENT RADAR IS SHOWING SOME CONVECTIVE ELEMENTS
WITHIN THE INCREASING COVERAGE OF THE RAIN IS RESPONSE TO STEEP
MID LEVEL LAPSE RATES...THE DYNAMICS ALOFT AND SURPRISINGLY
MU CAPES CLOSE TO 200 J/KG. THIS COULD LEAD TO LOCALLY HIGHER
RAIN TOTALS...AS WELL AS POSSIBLE SOME THUNDER AND LIGHTNING.

LOW STRATUS AND STRATOCUMULUS CLOUD DECKS WILL LOWER FURTHER AND
THIS WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA
WHERE THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR.
HOWEVER...WE MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND
NW WITH LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF
DENSE FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF LIGHT TO MODERATE RAINS. THERE
ARE ACTUAL EVEN SOME CONVECTIVE ELEMENTS EMBEDDED WITHIN THE RAIN
SHIELD EARLY TONIGHT...BUT ANY DIRECT HIT FROM A TSRA AT THE
TERMINAL IS FAR TO LOW TO INCLUDE AT THIS TIME.

KCHS...WHILE WE BEGIN THE VALID 00Z CYCLE WITH MVFR
CONDITIONS...WITH OVER-RUNNING RAINS TO ARRIVE THROUGH THE NIGHT
IT WILL RE-ENFORCE THE WEDGE INVERSION ATOP THE TERMINAL. THIS
WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE OVERNIGHT AND
THROUGH THE BALANCE OF THE PERIOD. SIMILAR TO KSAV THERE IS A
MINUTE RISK OF TSRA LATER THIS EVENING AND OVERNIGHT. WE CONTINUE
TO KEEP A WATCH FOR MARGINAL LOW LEVEL WIND SHEAR AS WINDS AT 1-2K
FT ARE FORECAST TO BE EASTERLY AS HIGH AS 25-30 KT A LITTLE LATER
TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT HAS PINCHED FURTHER THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE CHOSEN TO RAISE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15 KT...BUT WINDS PICK UP TO AROUND 20 KT AND GUSTY
NEAR THE HARBOR ENTRANCE. AS THE ATLANTIC WAVE DROPS A COUPLE
MILLIBARS AND GATHERS A CLOSED CIRCULATION OVERNIGHT IT WILL LIFT
NE. AS THIS OCCURS WE LOOK FOR A DROP IN WINDS AND GRADUALLY ALSO
IN THE SEAS TOO. LOW STRATUS AND PERIODS OF RAIN WILL OCCASIONALLY
DROP VISIBILITIES UNDER 2 OR 3 NM THROUGH THE NIGHT. PLUS THERE
CAN ALSO BE A LITTLE THUNDER AND LIGHTNING IN A FEW TALLER
CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
     354.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...











000
FXUS62 KCHS 212351
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
651 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM THIS EVENING...BUT GIVEN
CONSIDERABLE RAINS THIS WILL ACT TO SHUNT ANY RELAXATION OF THE
GRIP OF THE WEDGE BACK TO THE SOUTH.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE TOWARD THE LOCAL AREA.

SHORT WAVES EMBEDDED WITHIN THE SW FLOW UPSTAIRS WILL HEAD INTO
THE REGION LATER THIS EVENING AND OVERNIGHT...CAUSING WEAK
CYCLOGENESIS TO OCCUR OFF THE SE COAST NEAR THE GULF
STREAM...BEFORE IT TRIES TO DEVELOP SOME CLOSED ISOBARS BY
MORNING. THE PROXIMITY TO THIS FEATURE AND INCREASING ISENTROPIC
LIFT WILL FUEL THE EXPANSION OF LIGHT TO MODERATE RAINS TONIGHT.
THIS WILL BE AIDED FURTHER BY THE DYNAMICS OF THE SHORT WAVES ALOFT
AND LARGE SCALE FORCING FROM THE RIGHT REAR QUAD OF A 125 KT UPPER
JET. SUFFICE TO SAY WE/RE IN FOR MORE RAINFALL. WITH PWATS
CLIMBING TO 1.2 TO 1.4 INCHES WHICH IS WELL ABOVE LATE DECEMBER
NORMS...WE ANTICIPATE ON AVERAGE ABOUT 1/3 TO 2/3 INCHES OF RAIN.
IN ADDITION RECENT RADAR IS SHOWING SOME CONVECTIVE ELEMENTS
WITHIN THE INCREASING COVERAGE OF THE RAIN IS RESPONSE TO STEEP
MID LEVEL LAPSE RATES...THE DYNAMICS ALOFT AND SURPRISINGLY
MU CAPES CLOSE TO 2000 J/KG. THIS COULD LEAD TO LOCALLY HIGHER
RAIN TOTALS...AS WELL AS POSSIBLE SOME THUNDER AND LIGHTNING.

LOW STRATUS AND STRATOCUMULUS CLOUD DECKS WILL LOWER FURTHER AND
THIS WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA
WHERE THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR.
HOWEVER...WE MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND
NW WITH LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF
DENSE FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF LIGHT TO MODERATE RAINS. THERE
ARE ACTUAL EVEN SOME CONVECTIVE ELEMENTS EMBEDDED WITHIN THE RAIN
SHIELD EARLY TONIGHT...BUT ANY DIRECT HIT FROM A TSRA AT THE
TERMINAL IS FAR TO LOW TO INCLUDE AT THIS TIME.

KCHS...WHILE WE BEGIN THE VALID 00Z CYCLE WITH MVFR
CONDITIONS...WITH OVER-RUNNING RAINS TO ARRIVE THROUGH THE NIGHT
IT WILL RE-ENFORCE THE WEDGE INVERSION ATOP THE TERMINAL. THIS
WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE OVERNIGHT AND
THROUGH THE BALANCE OF THE PERIOD. SIMILAR TO KSAV THERE IS A
MINUTE RISK OF TSRA LATER THIS EVENING AND OVERNIGHT. WE CONTINUE
TO KEEP A WATCH FOR MARGINAL LOW LEVEL WIND SHEAR AS WINDS AT 1-2K
FT ARE FORECAST TO BE EASTERLY AS HIGH AS 25-30 KT A LITTLE LATER
TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT HAS PINCHED FURTHER THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE CHOSEN TO RAISE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15 KT...BUT WINDS PICK UP TO AROUND 20 KT AND GUSTY
NEAR THE HARBOR ENTRANCE. AS THE ATLANTIC WAVE DROPS A COUPLE
MILLIBARS AND GATHERS A CLOSED CIRCULATION OVERNIGHT IT WILL LIFT
NE. AS THIS OCCURS WE LOOK FOR A DROP IN WINDS AND GRADUALLY ALSO
IN THE SEAS TOO. LOW STRATUS AND PERIODS OF RAIN WILL OCCASIONALLY
DROP VISIBILITIES UNDER 2 OR 3 NM THROUGH THE NIGHT. PLUS THERE
CAN ALSO BE A LITTLE THUNDER AND LIGHTNING IN A FEW TALLER
CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
     354.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 212351
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
651 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM THIS EVENING...BUT GIVEN
CONSIDERABLE RAINS THIS WILL ACT TO SHUNT ANY RELAXATION OF THE
GRIP OF THE WEDGE BACK TO THE SOUTH.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE TOWARD THE LOCAL AREA.

SHORT WAVES EMBEDDED WITHIN THE SW FLOW UPSTAIRS WILL HEAD INTO
THE REGION LATER THIS EVENING AND OVERNIGHT...CAUSING WEAK
CYCLOGENESIS TO OCCUR OFF THE SE COAST NEAR THE GULF
STREAM...BEFORE IT TRIES TO DEVELOP SOME CLOSED ISOBARS BY
MORNING. THE PROXIMITY TO THIS FEATURE AND INCREASING ISENTROPIC
LIFT WILL FUEL THE EXPANSION OF LIGHT TO MODERATE RAINS TONIGHT.
THIS WILL BE AIDED FURTHER BY THE DYNAMICS OF THE SHORT WAVES ALOFT
AND LARGE SCALE FORCING FROM THE RIGHT REAR QUAD OF A 125 KT UPPER
JET. SUFFICE TO SAY WE/RE IN FOR MORE RAINFALL. WITH PWATS
CLIMBING TO 1.2 TO 1.4 INCHES WHICH IS WELL ABOVE LATE DECEMBER
NORMS...WE ANTICIPATE ON AVERAGE ABOUT 1/3 TO 2/3 INCHES OF RAIN.
IN ADDITION RECENT RADAR IS SHOWING SOME CONVECTIVE ELEMENTS
WITHIN THE INCREASING COVERAGE OF THE RAIN IS RESPONSE TO STEEP
MID LEVEL LAPSE RATES...THE DYNAMICS ALOFT AND SURPRISINGLY
MU CAPES CLOSE TO 2000 J/KG. THIS COULD LEAD TO LOCALLY HIGHER
RAIN TOTALS...AS WELL AS POSSIBLE SOME THUNDER AND LIGHTNING.

LOW STRATUS AND STRATOCUMULUS CLOUD DECKS WILL LOWER FURTHER AND
THIS WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA
WHERE THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR.
HOWEVER...WE MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND
NW WITH LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF
DENSE FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF LIGHT TO MODERATE RAINS. THERE
ARE ACTUAL EVEN SOME CONVECTIVE ELEMENTS EMBEDDED WITHIN THE RAIN
SHIELD EARLY TONIGHT...BUT ANY DIRECT HIT FROM A TSRA AT THE
TERMINAL IS FAR TO LOW TO INCLUDE AT THIS TIME.

KCHS...WHILE WE BEGIN THE VALID 00Z CYCLE WITH MVFR
CONDITIONS...WITH OVER-RUNNING RAINS TO ARRIVE THROUGH THE NIGHT
IT WILL RE-ENFORCE THE WEDGE INVERSION ATOP THE TERMINAL. THIS
WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE OVERNIGHT AND
THROUGH THE BALANCE OF THE PERIOD. SIMILAR TO KSAV THERE IS A
MINUTE RISK OF TSRA LATER THIS EVENING AND OVERNIGHT. WE CONTINUE
TO KEEP A WATCH FOR MARGINAL LOW LEVEL WIND SHEAR AS WINDS AT 1-2K
FT ARE FORECAST TO BE EASTERLY AS HIGH AS 25-30 KT A LITTLE LATER
TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT HAS PINCHED FURTHER THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE CHOSEN TO RAISE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15 KT...BUT WINDS PICK UP TO AROUND 20 KT AND GUSTY
NEAR THE HARBOR ENTRANCE. AS THE ATLANTIC WAVE DROPS A COUPLE
MILLIBARS AND GATHERS A CLOSED CIRCULATION OVERNIGHT IT WILL LIFT
NE. AS THIS OCCURS WE LOOK FOR A DROP IN WINDS AND GRADUALLY ALSO
IN THE SEAS TOO. LOW STRATUS AND PERIODS OF RAIN WILL OCCASIONALLY
DROP VISIBILITIES UNDER 2 OR 3 NM THROUGH THE NIGHT. PLUS THERE
CAN ALSO BE A LITTLE THUNDER AND LIGHTNING IN A FEW TALLER
CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
     354.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 212351
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
651 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM THIS EVENING...BUT GIVEN
CONSIDERABLE RAINS THIS WILL ACT TO SHUNT ANY RELAXATION OF THE
GRIP OF THE WEDGE BACK TO THE SOUTH.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE TOWARD THE LOCAL AREA.

SHORT WAVES EMBEDDED WITHIN THE SW FLOW UPSTAIRS WILL HEAD INTO
THE REGION LATER THIS EVENING AND OVERNIGHT...CAUSING WEAK
CYCLOGENESIS TO OCCUR OFF THE SE COAST NEAR THE GULF
STREAM...BEFORE IT TRIES TO DEVELOP SOME CLOSED ISOBARS BY
MORNING. THE PROXIMITY TO THIS FEATURE AND INCREASING ISENTROPIC
LIFT WILL FUEL THE EXPANSION OF LIGHT TO MODERATE RAINS TONIGHT.
THIS WILL BE AIDED FURTHER BY THE DYNAMICS OF THE SHORT WAVES ALOFT
AND LARGE SCALE FORCING FROM THE RIGHT REAR QUAD OF A 125 KT UPPER
JET. SUFFICE TO SAY WE/RE IN FOR MORE RAINFALL. WITH PWATS
CLIMBING TO 1.2 TO 1.4 INCHES WHICH IS WELL ABOVE LATE DECEMBER
NORMS...WE ANTICIPATE ON AVERAGE ABOUT 1/3 TO 2/3 INCHES OF RAIN.
IN ADDITION RECENT RADAR IS SHOWING SOME CONVECTIVE ELEMENTS
WITHIN THE INCREASING COVERAGE OF THE RAIN IS RESPONSE TO STEEP
MID LEVEL LAPSE RATES...THE DYNAMICS ALOFT AND SURPRISINGLY
MU CAPES CLOSE TO 2000 J/KG. THIS COULD LEAD TO LOCALLY HIGHER
RAIN TOTALS...AS WELL AS POSSIBLE SOME THUNDER AND LIGHTNING.

LOW STRATUS AND STRATOCUMULUS CLOUD DECKS WILL LOWER FURTHER AND
THIS WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA
WHERE THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR.
HOWEVER...WE MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND
NW WITH LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF
DENSE FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF LIGHT TO MODERATE RAINS. THERE
ARE ACTUAL EVEN SOME CONVECTIVE ELEMENTS EMBEDDED WITHIN THE RAIN
SHIELD EARLY TONIGHT...BUT ANY DIRECT HIT FROM A TSRA AT THE
TERMINAL IS FAR TO LOW TO INCLUDE AT THIS TIME.

KCHS...WHILE WE BEGIN THE VALID 00Z CYCLE WITH MVFR
CONDITIONS...WITH OVER-RUNNING RAINS TO ARRIVE THROUGH THE NIGHT
IT WILL RE-ENFORCE THE WEDGE INVERSION ATOP THE TERMINAL. THIS
WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE OVERNIGHT AND
THROUGH THE BALANCE OF THE PERIOD. SIMILAR TO KSAV THERE IS A
MINUTE RISK OF TSRA LATER THIS EVENING AND OVERNIGHT. WE CONTINUE
TO KEEP A WATCH FOR MARGINAL LOW LEVEL WIND SHEAR AS WINDS AT 1-2K
FT ARE FORECAST TO BE EASTERLY AS HIGH AS 25-30 KT A LITTLE LATER
TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT HAS PINCHED FURTHER THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE CHOSEN TO RAISE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15 KT...BUT WINDS PICK UP TO AROUND 20 KT AND GUSTY
NEAR THE HARBOR ENTRANCE. AS THE ATLANTIC WAVE DROPS A COUPLE
MILLIBARS AND GATHERS A CLOSED CIRCULATION OVERNIGHT IT WILL LIFT
NE. AS THIS OCCURS WE LOOK FOR A DROP IN WINDS AND GRADUALLY ALSO
IN THE SEAS TOO. LOW STRATUS AND PERIODS OF RAIN WILL OCCASIONALLY
DROP VISIBILITIES UNDER 2 OR 3 NM THROUGH THE NIGHT. PLUS THERE
CAN ALSO BE A LITTLE THUNDER AND LIGHTNING IN A FEW TALLER
CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
     354.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 212351
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
651 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
OUR DAMP...COOL AND UNSETTLED WEATHER PATTERN WILL PERSIST TONIGHT
WITH THE STRONG INLAND WEDGE OF HIGH PRESSURE GOING NOWHERE ANY
TIME SOON. IT/LL TRY TO GET NUDGED A LITTLE AS WEAK CYCLOGENESIS
TRANSPIRES OUT NEAR THE GULF STREAM THIS EVENING...BUT GIVEN
CONSIDERABLE RAINS THIS WILL ACT TO SHUNT ANY RELAXATION OF THE
GRIP OF THE WEDGE BACK TO THE SOUTH.

ONE CAN CERTAINLY ASCERTAIN WHERE THE MAIN BAROCLINIC ZONE AND
WARM CONVEYOR BELT IS FOUND...STREAMING FROM SW TO NE ACROSS THE
GULF AND SE PART OF THE NATION. THIS IS ALSO WELL ANALYZED BY THE
BLENDED PW PRODUCT THAT SHOWS THIS DEEPER TROPICAL-LIKE MOISTURE
STREAMING NE TOWARD THE LOCAL AREA.

SHORT WAVES EMBEDDED WITHIN THE SW FLOW UPSTAIRS WILL HEAD INTO
THE REGION LATER THIS EVENING AND OVERNIGHT...CAUSING WEAK
CYCLOGENESIS TO OCCUR OFF THE SE COAST NEAR THE GULF
STREAM...BEFORE IT TRIES TO DEVELOP SOME CLOSED ISOBARS BY
MORNING. THE PROXIMITY TO THIS FEATURE AND INCREASING ISENTROPIC
LIFT WILL FUEL THE EXPANSION OF LIGHT TO MODERATE RAINS TONIGHT.
THIS WILL BE AIDED FURTHER BY THE DYNAMICS OF THE SHORT WAVES ALOFT
AND LARGE SCALE FORCING FROM THE RIGHT REAR QUAD OF A 125 KT UPPER
JET. SUFFICE TO SAY WE/RE IN FOR MORE RAINFALL. WITH PWATS
CLIMBING TO 1.2 TO 1.4 INCHES WHICH IS WELL ABOVE LATE DECEMBER
NORMS...WE ANTICIPATE ON AVERAGE ABOUT 1/3 TO 2/3 INCHES OF RAIN.
IN ADDITION RECENT RADAR IS SHOWING SOME CONVECTIVE ELEMENTS
WITHIN THE INCREASING COVERAGE OF THE RAIN IS RESPONSE TO STEEP
MID LEVEL LAPSE RATES...THE DYNAMICS ALOFT AND SURPRISINGLY
MU CAPES CLOSE TO 2000 J/KG. THIS COULD LEAD TO LOCALLY HIGHER
RAIN TOTALS...AS WELL AS POSSIBLE SOME THUNDER AND LIGHTNING.

LOW STRATUS AND STRATOCUMULUS CLOUD DECKS WILL LOWER FURTHER AND
THIS WILL RESULT IN AT LEAST PATCHY FOG SOUTH OF I-16 IN SE GA
WHERE THE LOWEST CONDENSATION PRESSURE DEFICITS WILL OCCUR.
HOWEVER...WE MAY NEED TO EXPAND THE FOG COVERAGE FURTHER NORTH AND
NW WITH LATER UPDATES...AS WELL AS CONSIDERING POSSIBLE PATCHES OF
DENSE FOG.

TEMPS WON/T CHANGE MUCH WITHIN THIS PATTERN DUE TO THE OVERCAST
SKIES AND EXTENSIVE RAINS. PLUS THE COOLER AIR REMAINS TRAPPED
UNDERNEATH THE WARM ADVECTION...KEEPING MOST OF US IN THE 40S
THROUGH THE NIGHT.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WEATHER POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
KSAV...THE TERMINAL MOST LIKELY WILL REMAIN TANKED AS A STRONG
WEDGE INVERSION PERSISTS JUST OFF THE DECK AND GENERATES IFR OR
LOWER CONDITIONS THROUGH 00Z TUESDAY. IN ADDITION...MID AND UPPER
LEVEL ENERGY AND THE PROXIMITY TO A COASTAL WARM FRONT NEAR THE
GULF STREAM WILL PRODUCE PERIODS OF LIGHT TO MODERATE RAINS. THERE
ARE ACTUAL EVEN SOME CONVECTIVE ELEMENTS EMBEDDED WITHIN THE RAIN
SHIELD EARLY TONIGHT...BUT ANY DIRECT HIT FROM A TSRA AT THE
TERMINAL IS FAR TO LOW TO INCLUDE AT THIS TIME.

KCHS...WHILE WE BEGIN THE VALID 00Z CYCLE WITH MVFR
CONDITIONS...WITH OVER-RUNNING RAINS TO ARRIVE THROUGH THE NIGHT
IT WILL RE-ENFORCE THE WEDGE INVERSION ATOP THE TERMINAL. THIS
WILL LEAD TO IFR OR LOWER CONDITIONS DURING THE OVERNIGHT AND
THROUGH THE BALANCE OF THE PERIOD. SIMILAR TO KSAV THERE IS A
MINUTE RISK OF TSRA LATER THIS EVENING AND OVERNIGHT. WE CONTINUE
TO KEEP A WATCH FOR MARGINAL LOW LEVEL WIND SHEAR AS WINDS AT 1-2K
FT ARE FORECAST TO BE EASTERLY AS HIGH AS 25-30 KT A LITTLE LATER
TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
TONIGHT...THE NE PRESSURE GRADIENT HAS PINCHED FURTHER THIS
EVENING BETWEEN A DEVELOPING WAVE OF LOW PRESSURE OFF THE SE COAST
OUT NEAR THE GULF STREAM AND AN ANCHORED WEDGE OF HIGH PRESSURE
INLAND. AS A RESULT WE HAVE CHOSEN TO RAISE SMALL CRAFT ADVISORIES
FOR ALL 0-20 NM WATERS...WHERE NE WINDS WILL PEAK AT 20-25 KT AND
GUSTY AND SEAS WILL HIT 4-6 FT. ACROSS THE OUTER GA WATERS THE
GRADIENT WILL CONTINUE TO SLACKEN AND WINDS WILL BE UNDER 20 KT.
WHILE A FEW 6 FOOTERS WILL OCCUR TO THE NW OF THE LOW...THE BULK
OF THE AMZ374 SEAS WILL BE LIMITED TO 5 FT. IN CHARLESTON HARBOR
WE WILL SHOW 15 KT...BUT WINDS PICK UP TO AROUND 20 KT AND GUSTY
NEAR THE HARBOR ENTRANCE. AS THE ATLANTIC WAVE DROPS A COUPLE
MILLIBARS AND GATHERS A CLOSED CIRCULATION OVERNIGHT IT WILL LIFT
NE. AS THIS OCCURS WE LOOK FOR A DROP IN WINDS AND GRADUALLY ALSO
IN THE SEAS TOO. LOW STRATUS AND PERIODS OF RAIN WILL OCCASIONALLY
DROP VISIBILITIES UNDER 2 OR 3 NM THROUGH THE NIGHT. PLUS THERE
CAN ALSO BE A LITTLE THUNDER AND LIGHTNING IN A FEW TALLER
CONVECTIVE CLOUD ELEMENTS.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEW POINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
     354.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350.

&&

$$

NEAR TERM...
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 212037
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
337 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
CLOUDY AND DAMP WILL BE THE RULE TONIGHT AS ANOTHER IN A SERIES OF
SHORTWAVES IS EXPECTED TO MOVE FROM THE CENTRAL GULF OF MEXICO
LATE THIS AFTERNOON ACROSS THE CWA DURING THE OVERNIGHT HOURS. THE
AREA WILL REMAIN IN THE GENERAL RIGHT ENTRANCE REGION OF A 125+
KNOT JET OVER THE SOUTHEASTERN QUARTER OF THE COUNTRY...AND
ISENTROPIC LIFT WILL ALSO SUPPORT CLOUDS AND PERIODS OF RAIN.

THE BLENDED PW PRODUCT SHOWS SOME DEEPER MOISTURE BEGINNING TO
MOVE NORTHEASTWARD OUT OF THE GULF OF MEXICO...BUT WITH THE MAIN
SURFACE FRONT EXPECTED TO BE WELL SOUTH OF THE AREA
OVERNIGHT...THE MAIN INSTABILITY SHOULD STAY OUT OF THE CWA.
THEREFORE...I AM KEEPING THE MENTION OF THUNDER AND ANY HEAVY RAIN
OUT OF THE FORECAST FOR TONIGHT. EVEN THOUGH THE RAIN IS EXPECTED
TO BE GENERALLY ON THE LIGHT SIDE COVERAGE SHOULD BE
WIDESPREAD...SO CATEGORICAL POPS WILL BE IN THE FORECAST.

WITH WEDGE REMAINING IN PLACE OVERNIGHT...ALBEIT WEAKENING A
TOUCH...AND A WEAK SURFACE WAVE EXPECTED TO FORM JUST
OFFSHORE...NORTH TO NORTHEAST WINDS WILL RULE...KEEPING CONDITIONS
ON THE COOL SIDE. TEMPS SHOULD BOTTOM OUT IN THE 40S
EVERYWHERE...COOLEST NORTH. THERE IS A POSSIBILITY THAT THE COASTAL
FRONT WILL TRY TO SNEAK ONSHORE IN THE SOUTHERNMOST CWA ALONG THE
MCINTOSH COUNTY COAST...BUT I THINK THE WEDGE WILL HOLD IN STRONG
ENOUGH THROUGH 12Z SO THAT IT WONT BE MUCH OF A FACTOR.


&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WX POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.


&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
KCHS...I EXPECT THE CIGS TO START LOWERING AGAIN IN THE NEXT FEW
HOURS...WITH MVFR CONDITIONS DEVELOPING LATE THIS AFTERNOON AND
IFR BY EVENING. ONCE THE CIGS DROP DOWN...THEY WILL LIKELY STAY
DOWN INTO MONDAY MORNING.

KSAV...CURRENT THINKING IS THAT THE IFR CIGS WILL HAVE A HARD TIME
BREAKING OUT OVER THE NEXT 24 HOURS WITH WEDGE NOT BUDGING MUCH.
IT IS POSSIBLE THAT SOME LIFR CONDITIONS MIGHT DEVELOP LATE
TONIGHT WITH CIGS BELOW 500 FT.


EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
I TOYED WITH PUTTING UP SMALL CRAFT ADVISORIES THIS EVENING...BUT
I THINK WE WILL REMAIN JUST BELOW CRITERIA. SEAS HAVE COME DOWN TO
6 FEET AT BUOY 41004 AND REMAIN AT 5 FEET FOR BUOY 41008...SO I
THINK THE NEAR SHORE WATERS WILL MAX OUT AT 5 FEET WITH 20 KNOT
WINDS OVERNIGHT. THERE MAY STILL BE SOME 6 FOOTERS IN THE OFFSHORE
GEORGIA WATERS RIGHT NOW...BUT WINDS ARE DROPPING SOME AT
41008...AND THIS TREND SHOULD CONTINUE...SO I PLAN ON LETTING THE
CURRENT SCA FOR THE OUTER GEORGIA WATERS EXPIRE AT 4 PM.

ALSO OVER THE OUTER GEORGIA WATERS...WE SHOULD SEE THE WINDS
GRADUALLY VEER TO A MORE SOUTHEASTERLY DIRECTION AS A WAVE FORMS
ALONG THE COASTAL FRONT AND MOVES NORTHEASTWARD. THIS WILL ALSO
ACT TO KNOCK DOWN THE SEAS AS THE EXTENDED NORTHEASTERLY FETCH
BREAKS DOWN FOR A LITTLE WHILE.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEWPOINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.


&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...FWA
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...FWA
MARINE...FWA/JRL
TIDES/COASTAL FLOODING...JRL








000
FXUS62 KCHS 212037
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
337 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
MOVE THROUGH THE AREA WEDNESDAY EVENING. DRY HIGH PRESSURE WILL
SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
CLOUDY AND DAMP WILL BE THE RULE TONIGHT AS ANOTHER IN A SERIES OF
SHORTWAVES IS EXPECTED TO MOVE FROM THE CENTRAL GULF OF MEXICO
LATE THIS AFTERNOON ACROSS THE CWA DURING THE OVERNIGHT HOURS. THE
AREA WILL REMAIN IN THE GENERAL RIGHT ENTRANCE REGION OF A 125+
KNOT JET OVER THE SOUTHEASTERN QUARTER OF THE COUNTRY...AND
ISENTROPIC LIFT WILL ALSO SUPPORT CLOUDS AND PERIODS OF RAIN.

THE BLENDED PW PRODUCT SHOWS SOME DEEPER MOISTURE BEGINNING TO
MOVE NORTHEASTWARD OUT OF THE GULF OF MEXICO...BUT WITH THE MAIN
SURFACE FRONT EXPECTED TO BE WELL SOUTH OF THE AREA
OVERNIGHT...THE MAIN INSTABILITY SHOULD STAY OUT OF THE CWA.
THEREFORE...I AM KEEPING THE MENTION OF THUNDER AND ANY HEAVY RAIN
OUT OF THE FORECAST FOR TONIGHT. EVEN THOUGH THE RAIN IS EXPECTED
TO BE GENERALLY ON THE LIGHT SIDE COVERAGE SHOULD BE
WIDESPREAD...SO CATEGORICAL POPS WILL BE IN THE FORECAST.

WITH WEDGE REMAINING IN PLACE OVERNIGHT...ALBEIT WEAKENING A
TOUCH...AND A WEAK SURFACE WAVE EXPECTED TO FORM JUST
OFFSHORE...NORTH TO NORTHEAST WINDS WILL RULE...KEEPING CONDITIONS
ON THE COOL SIDE. TEMPS SHOULD BOTTOM OUT IN THE 40S
EVERYWHERE...COOLEST NORTH. THERE IS A POSSIBILITY THAT THE COASTAL
FRONT WILL TRY TO SNEAK ONSHORE IN THE SOUTHERNMOST CWA ALONG THE
MCINTOSH COUNTY COAST...BUT I THINK THE WEDGE WILL HOLD IN STRONG
ENOUGH THROUGH 12Z SO THAT IT WONT BE MUCH OF A FACTOR.


&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE ON MONDAY AS A COOL WEDGE
OF HIGH PRESSURE REMAINS ENTRENCHED ACROSS LAND AREAS AND THE
OVERNIGHT COASTAL LOW SHIFTS NORTHEAST AWAY FROM THE AREA. THE BEST
FORCING WILL MOVE AWAY DURING THE MORNING BUT WE WILL STILL SEE
MODERATE ISENTROPIC ASCENT CONTINUING THROUGH EARLY TO MID AFTERNOON
ALONG WITH WEAK UPPER JET DIVERGENCE. WE SHOW LIKELY POPS IN THE
MORNING...TAPERING BACK TO CHANCE POPS IN THE AFTERNOON WITH HIGHEST
VALUES OVER THE WATERS. QPF WILL BE FAIRLY LIGHT BUT SCATTERED RAIN
WILL PERSIST NONETHELESS. CLOUDY SKIES...COLD ADVECTION AND
EVAPORATIONAL COOLING WILL KEEP HIGH TEMPS IN THE 50S.

ON TUESDAY THE WEDGE WILL LIKELY PERSIST AT LEAST THROUGH EARLY
AFTERNOON. SOME EROSION IS POSSIBLE OVER SOUTHERN AND EASTERN AREAS
AS THE UPPER TROUGH DEEPENS TO THE WEST AND THE COASTAL TROUGH
SHIFTS INLAND. INCREASING SHORTWAVE ENERGY WILL LIFT OUT OF THE GULF
COAST REGION DURING THE AFTERNOON...COINCIDENT WITH A BROAD AREA OF
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RT ENTRANCE REGION OF A
155 KT JET. PWATS ARE ALSO PROGGED TO INCREASE TO 1.75" OR HIGHER
DURING THE AFTERNOON. WIDESPREAD SHOWERS WILL OVERSPREAD THE AREA
FROM SW TO NE DURING THE DAY. MODELS INDICATE SOME ELEVATED
INSTABILITY ACROSS SOUTHEAST PORTIONS SO WE MAINTAINED SLIGHT CHANCE
THUNDER DURING THE AFTERNOON. SOME TEMPERATURE RECOVERY IS EXPECTED
IN SOUTHERN AND COASTAL AREAS WHERE THE WINDS VEER TO E OR SE. HIGHS
WILL RANGE FROM LOWER 60S INLAND TO UPPER 60S ALONG THE ALTAMAHA
RIVER.

WIDESPREAD RAIN...LOCALLY HEAVY...WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY AHEAD OF THE COLD FRONT. THE GFS SHOWS IMPRESSIVE PWATS
EXCEEDING 2 INCHES ALONG THE SC COAST AT 12Z WEDNESDAY. NEEDLESS TO
SAY THERE WILL BE NO SHORTAGE OF MOISTURE WITH THIS SYSTEM. THE
WEDGE WILL ERODE AT SOME POINT ON WEDNESDAY WITH STRONG WARM AIR
ADVECTION KICKING IN. TEMPS WILL PUSH INTO THE UPPER 60S TO LOWER
70S DESPITE LITTLE TO NO INSOLATION. LOW-LEVEL WIND FIELDS WILL BE
IMPRESSIVE AHEAD OF THE COLD FRONT. GEOSTROPHIC WINDS WILL INCREASE
TO 35-40 KT DURING THE DAY WHICH WILL EQUATE TO 15-25 MPH SURFACE
WINDS. SEVERE WX POTENTIAL STILL LOOKS LOW DUE TO A LIMITED
OPPORTUNITY FOR BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FROPA.
WE DID MAINTAIN A SLIGHT CHANCE OF TSTMS ON WEDNESDAY DUE TO SOME
ELEVATED INSTABILITY BUT THE HAIL AND DAMAGING WIND THREAT ARE
MARGINAL AT BEST.


&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
KCHS...I EXPECT THE CIGS TO START LOWERING AGAIN IN THE NEXT FEW
HOURS...WITH MVFR CONDITIONS DEVELOPING LATE THIS AFTERNOON AND
IFR BY EVENING. ONCE THE CIGS DROP DOWN...THEY WILL LIKELY STAY
DOWN INTO MONDAY MORNING.

KSAV...CURRENT THINKING IS THAT THE IFR CIGS WILL HAVE A HARD TIME
BREAKING OUT OVER THE NEXT 24 HOURS WITH WEDGE NOT BUDGING MUCH.
IT IS POSSIBLE THAT SOME LIFR CONDITIONS MIGHT DEVELOP LATE
TONIGHT WITH CIGS BELOW 500 FT.


EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
I TOYED WITH PUTTING UP SMALL CRAFT ADVISORIES THIS EVENING...BUT
I THINK WE WILL REMAIN JUST BELOW CRITERIA. SEAS HAVE COME DOWN TO
6 FEET AT BUOY 41004 AND REMAIN AT 5 FEET FOR BUOY 41008...SO I
THINK THE NEAR SHORE WATERS WILL MAX OUT AT 5 FEET WITH 20 KNOT
WINDS OVERNIGHT. THERE MAY STILL BE SOME 6 FOOTERS IN THE OFFSHORE
GEORGIA WATERS RIGHT NOW...BUT WINDS ARE DROPPING SOME AT
41008...AND THIS TREND SHOULD CONTINUE...SO I PLAN ON LETTING THE
CURRENT SCA FOR THE OUTER GEORGIA WATERS EXPIRE AT 4 PM.

ALSO OVER THE OUTER GEORGIA WATERS...WE SHOULD SEE THE WINDS
GRADUALLY VEER TO A MORE SOUTHEASTERLY DIRECTION AS A WAVE FORMS
ALONG THE COASTAL FRONT AND MOVES NORTHEASTWARD. THIS WILL ALSO
ACT TO KNOCK DOWN THE SEAS AS THE EXTENDED NORTHEASTERLY FETCH
BREAKS DOWN FOR A LITTLE WHILE.

EXTENDED MARINE...A WEAK WEDGE OF HIGH PRESSURE TO THE NORTH WILL
MAINTAIN PERSISTENT NORTHEAST WINDS OVER THE WATERS MONDAY AND
TUESDAY WITH SEAS GENERALLY 3-4 FT BUT NO ADVISORIES ANTICIPATED.

WINDS VEER AROUND TO SOUTHERLY LATE TUESDAY NIGHT INTO WEDNESDAY AS
THE WEDGE SCOURS OUT AND A COLD FRONT APPROACHES FROM THE WEST.
STRONG LOW-LEVEL JETTING AHEAD OF THE FRONT WILL LIKELY RESULT IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST/ALL OF THE MARINE ZONES BY
DAYBREAK WEDNESDAY.

GALE FORCE WIND GUSTS REMAIN POSSIBLE AS THE COLD FRONT SHIFTS
OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT WEDNESDAY NIGHT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY NIGHT AS WINDS GUST TO 30-35 KT AWAY FROM THE COAST.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS AND PERIODS OF RAIN OR DRIZZLE COULD REDUCE
VSBYS OVER THE WATERS AT TIMES. POTENTIAL FOR ACTUAL SEA FOG TO
DEVELOP TUESDAY AND PERSIST INTO WEDNESDAY EVENING AS 60 PLUS
DEWPOINTS MOVE OVER THE COOL SHELF WATERS FROM THE SOUTH.


&&

.TIDES/COASTAL FLOODING...
GIVEN THE PERIGEAN SPRING TIDES AND PERSISTENT NORTHEAST WINDS THERE
IS AN INCREASING RISK FOR SHALLOW COASTAL FLOODING WITH THE MORNING
HIGH TIDES MONDAY AND TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...FWA
SHORT TERM...JRL
LONG TERM...DPB
AVIATION...FWA
MARINE...FWA/JRL
TIDES/COASTAL FLOODING...JRL







000
FXUS62 KCHS 211730
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1230 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN APPROACH
FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA WEDNESDAY
AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE WILL THEN SETTLE
OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
A FAIR AMOUNT OF THE RETURNS ON THE RADAR EARLY THIS AFTERNOON ARE
EITHER NOT REACHING THE GROUND OR JUST CAUSING SOME VERY LIGHT
RAIN AND DRIZZLE. THIS IS ONE OF THOSE SITUATIONS WHERE THERE WILL
LIKELY BE SOME RAIN MOST PLACES...BUT THE AMOUNTS WILL BE QUITE LOW AND
IT WONT HAVE A BIG EFFECT ON OUTDOOR ACTIVITIES. I WILL CONTINUE
WITH LIKELY POPS THIS AFTERNOON BUT ITS NOT A WASHOUT...EITHER.

TEMPS RIGHT NOW ARE RUNNING WITHIN A COUPLE OF DEGREES EITHER SIDE
OF 50...AND WITH THE COLD AIR WEDGE FIRMLY ENTRENCHED AND OVERCAST
SKIES EXPECTED...WE WILL LIKELY ONLY SEE ANOTHER COUPLE OF DEGREES
WARMING THIS AFTERNOON. THIS IS CAPTURED WELL IN THE CURRENT
FORECAST...SO NO CHANGES NEEDED.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER SHORT
WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE. MODELS INDICATE
A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION WILL LIFT THROUGH THE
REGION OVERNIGHT AND THIS SHOULD NUDGE THE COASTAL FRONT WELL OFFSHORE
JUST A BIT CLOSER IN...BUT THE WEDGE WILL REMAIN STRONG AND INTACT
ALL AREAS. 1/2 INCH OR LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE
ALONG COASTAL SE GEORGIA... OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS
TONIGHT. WE LOWERED LOW TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW
THE WARM ADVECTION. THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT
AS STRATUS COULD BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST
CONCERN IS INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME
STRONGER FOG MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
KCHS...I HAVE CONTINUED TO BACK OFF ON THE IFR CONDITIONS FOR THE
NEXT SEVERAL HOURS...ALTHOUGH THEY ARE EXPECTED TO REDEVELOP LATE
THIS AFTERNOON AND REMAIN IN PLACE OVERNIGHT INTO EARLY MONDAY.

KSAV...CURRENT THINKING IS THAT THE IFR CIGS WILL HAVE A HARD TIME
BREAKING OUT OVER THE NEXT 24 HOURS WITH WEDGE NOT BUDGING MUCH.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
SCA WILL REMAIN IN PLACE FOR THE OUTER GEORGIA WATERS FOR THE
REMAINDER OF THE AFTERNOON...BUT WILL LIKELY BE ALLOWED TO EXPIRE
AT 4 PM AS GRADIENT SLOWLY RELAXES OVER THE GEORGIA WATERS.

TONIGHT AS THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE
RIDES THE GULF STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING
ALONG THE CHARLESTON COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE
TONIGHT. MODEL PROGS SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS
HAVE NOT DEVELOPED BY THIS EVENING....CHANCES ARE DECENT FOR
SLIGHTLY DIMINISHED WINDS AND SEAS AFTER MIDNIGHT. THERE MAY BE
SOME LOWER VSBYS AT TIMES TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD FRONT
THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT. SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE AS
THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY
BE NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS
GUST TO 30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS
TO 5-8 FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE
IMPROVING LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...FWA
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...FWA
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 211730
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1230 PM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN APPROACH
FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA WEDNESDAY
AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE WILL THEN SETTLE
OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
A FAIR AMOUNT OF THE RETURNS ON THE RADAR EARLY THIS AFTERNOON ARE
EITHER NOT REACHING THE GROUND OR JUST CAUSING SOME VERY LIGHT
RAIN AND DRIZZLE. THIS IS ONE OF THOSE SITUATIONS WHERE THERE WILL
LIKELY BE SOME RAIN MOST PLACES...BUT THE AMOUNTS WILL BE QUITE LOW AND
IT WONT HAVE A BIG EFFECT ON OUTDOOR ACTIVITIES. I WILL CONTINUE
WITH LIKELY POPS THIS AFTERNOON BUT ITS NOT A WASHOUT...EITHER.

TEMPS RIGHT NOW ARE RUNNING WITHIN A COUPLE OF DEGREES EITHER SIDE
OF 50...AND WITH THE COLD AIR WEDGE FIRMLY ENTRENCHED AND OVERCAST
SKIES EXPECTED...WE WILL LIKELY ONLY SEE ANOTHER COUPLE OF DEGREES
WARMING THIS AFTERNOON. THIS IS CAPTURED WELL IN THE CURRENT
FORECAST...SO NO CHANGES NEEDED.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER SHORT
WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE. MODELS INDICATE
A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION WILL LIFT THROUGH THE
REGION OVERNIGHT AND THIS SHOULD NUDGE THE COASTAL FRONT WELL OFFSHORE
JUST A BIT CLOSER IN...BUT THE WEDGE WILL REMAIN STRONG AND INTACT
ALL AREAS. 1/2 INCH OR LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE
ALONG COASTAL SE GEORGIA... OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS
TONIGHT. WE LOWERED LOW TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW
THE WARM ADVECTION. THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT
AS STRATUS COULD BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST
CONCERN IS INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME
STRONGER FOG MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
KCHS...I HAVE CONTINUED TO BACK OFF ON THE IFR CONDITIONS FOR THE
NEXT SEVERAL HOURS...ALTHOUGH THEY ARE EXPECTED TO REDEVELOP LATE
THIS AFTERNOON AND REMAIN IN PLACE OVERNIGHT INTO EARLY MONDAY.

KSAV...CURRENT THINKING IS THAT THE IFR CIGS WILL HAVE A HARD TIME
BREAKING OUT OVER THE NEXT 24 HOURS WITH WEDGE NOT BUDGING MUCH.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
SCA WILL REMAIN IN PLACE FOR THE OUTER GEORGIA WATERS FOR THE
REMAINDER OF THE AFTERNOON...BUT WILL LIKELY BE ALLOWED TO EXPIRE
AT 4 PM AS GRADIENT SLOWLY RELAXES OVER THE GEORGIA WATERS.

TONIGHT AS THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE
RIDES THE GULF STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING
ALONG THE CHARLESTON COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE
TONIGHT. MODEL PROGS SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS
HAVE NOT DEVELOPED BY THIS EVENING....CHANCES ARE DECENT FOR
SLIGHTLY DIMINISHED WINDS AND SEAS AFTER MIDNIGHT. THERE MAY BE
SOME LOWER VSBYS AT TIMES TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD FRONT
THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT. SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE AS
THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY
BE NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS
GUST TO 30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS
TO 5-8 FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE
IMPROVING LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...FWA
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...FWA
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 211430
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
930 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN APPROACH
FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA WEDNESDAY
AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE WILL THEN SETTLE
OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
I MADE THE MORNING UPDATE A LITTLE EARLIER THAN USUAL AS THERE IS
A CLEAR BREAK IN THE RAIN IN THE SOUTHWESTERN AREAS THAT SHOULD
MOVE ITS WAY UP THE COAST THROUGH THE REMINDER OF THE MORNING.
THIS IS DUE TO A COMBINATION OF A PUNCH OF MODESTLY DRIER IN THE
MID LEVELS...WHICH CAN BE SEEN IN THE 11Z POES SOUNDINGS IN
SOUTHEAST GEORGIA AND EXTREME SOUTHERN SC AS WELL AS INFERRED FROM
THE 7.4UM GOES SOUNDER CHANNEL...AND A SMALL AREA OF SUBSIDENCE BETWEEN
THE WAVE DEPARTING OFF THE SC COAST AND THE NEXT WAVE CURRENTLY IN
THE WESTERN GOMEX. THE RESULT IS A LOWERING OF POPS FOR THE NEXT
FEW HOURS BEFORE THINGS BEGIN TO FILL IN AGAIN LATER THIS
AFTERNOON WHEN THE STRONGER DIFFLUENCE AHEAD OF THE NEXT WAVE
BEGINS TO TAKE PLACE.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER SHORT
WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE. MODELS INDICATE
A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION WILL LIFT THROUGH THE
REGION OVERNIGHT AND THIS SHOULD NUDGE THE COASTAL FRONT WELL OFFSHORE
JUST A BIT CLOSER IN...BUT THE WEDGE WILL REMAIN STRONG AND INTACT
ALL AREAS. 1/2 INCH OR LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE
ALONG COASTAL SE GEORGIA... OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS
TONIGHT. WE LOWERED LOW TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW
THE WARM ADVECTION. THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT
AS STRATUS COULD BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST
CONCERN IS INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME
STRONGER FOG MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
KCHS...WITH THE DRIER AIR STARTING TO MOVE IN FOR A WHILE...I
BACKED OFF ON THE IFR CONDITIONS FOR THE NEXT SEVERAL HOURS...AND
MAY NEED TO BACK OFF ON THE REDEVELOPMENT TIME OF SUCH CONDITIONS
UNTIL LATER IN THE DAY WITH SUBSEQUENT UPDATES. IFR CONDITIONS ARE
STILL EXPECTED TO REDEVELOP LATE TODAY AND REMAIN IN PLACE TONIGHT.

KSAV...CURRENT THINKING IS THAT THE IFR CIGS WILL HAVE A HARD TIME
BREAKING OUT TODAY WITH THE WEDGE SOLIDLY IN PLACE...ALTHOUGH I
COULD NOT RULE OUT A PERIODIC BUT SHORT LIVED IMPROVEMENT OVER THE
NEXT FEW HOURS IF SOME OF THE DRIER AIR TRIES TO SNEAK INTO THE
AREA. IFR CONDITIONS LOOK PRETTY CERTAIN TONIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
CURRENT FORECAST LOOKS GOOD FOR WINDS AND SEAS...SO I MADE NO
CHANGES WITH THE MORNING UPDATE. BUOY 41008 STILL HASNT REACHED
SUSTAINED SCA CRITERIA...BUT I EXPECT IT IS OCCURRING IN Z374
CLOSER TO THE GULF STREAM. THE REMAINDER OF THE COASTAL WATERS
WILL LIKELY STAY JUST BELOW THE NEED FOR HEADLINES...BUT IT WILL
BE BREEZY AND CHOPPY NONETHELESS FOR MARINERS TODAY.

TONIGHT AS THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE
RIDES THE GULF STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING
ALONG THE CHARLESTON COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE
TONIGHT. MODEL PROGS SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS
HAVE NOT DEVELOPED BY THIS EVENING....CHANCES ARE DECENT FOR
SLIGHTLY DIMINISHED WINDS AND SEAS AFTER MIDNIGHT. THERE MAY BE
SOME LOWER VSBYS AT TIMES TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD FRONT
THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT. SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE AS
THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY
BE NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS
GUST TO 30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS
TO 5-8 FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE
IMPROVING LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...FWA
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...FWA
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 211228
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
728 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN APPROACH
FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA WEDNESDAY
AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE WILL THEN SETTLE
OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
OUR DAMP AND COOL FORECAST IS ON TRACK THROUGH TONIGHT...THE CHANGES
WE MADE THIS MORNING WERE TO MAKE IT A BIT COOLER AND EVEN DAMPER
IN SOME LOCATIONS. ISENTROPIC ASCENT WILL CONTINUE TO STEEPEN AND
EXPAND OVER GEORGIA AND SOUTH CAROLINA TODAY. ANOTHER SHORT WAVE
TROUGH WILL LIFT FROM NORTH GEORGIA THIS MORNING...THROUGH THE
CAROLINAS TODAY WHILE THE AXIS OF THE BAROCLINIC ZONE REMAINS
ENTRENCHED FROM NORTH CENTRAL FLORIDA TO THE GULF STREAM TO OUR
EAST. OUR FORECAST AREA WILL BE IN THE GRIPS OF AN ANCHORED
SURFACE WEDGE PATTERN WHICH WILL REMAIN LOCKED IN UNDER PERIODS OF
LIGHT RAINS AND A NOSE OF WARMING TEMPS AT 925 MB. WE LOWERED
TEMPS TODAY ACROSS THE BOARD GIVEN OVERNIGHT SURFACE ANALYSIS AND
AN EMPHATICALLY COOLER SURFACE TEMP TREND PROGGED BY MANY OF THE
00Z MODELS. SOME AREAS MAY STRUGGLE TO HIT 50 DEGREES TODAY TO THE
NORTH OF I-16...WHILE RAINS HOLD TEMPS DOWN IN THE LOWER TO MID
50S IN AREAS SUCH AS DARIEN AND LUDOWICI GEORGIA.

FORECAST SOUNDINGS AND MODEL PROJECTIONS INDICATE MANY AREAS WILL SEE
MEASURABLE LIGHT RAINS TODAY WITH HIGHEST CONFIDENCE ACROSS THE SE HALF
OF THE FORECAST AREA GIVEN THE PROXIMITY TO LOWER CONDENSATION PRES
DEFICITS AND DEEPER MOISTURE FIELDS. POPS AVERAGE OUT IN THE LIKELY
CATEGORY TODAY...BUT RAINFALL AMOUNTS ON THE LIGHT SIDE ONCE AGAIN.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER SHORT
WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE. MODELS INDICATE
A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION WILL LIFT THROUGH THE
REGION OVERNIGHT AND THIS SHOULD NUDGE THE COASTAL FRONT WELL OFFSHORE
JUST A BIT CLOSER IN...BUT THE WEDGE WILL REMAIN STRONG AND INTACT
ALL AREAS. 1/2 INCH OR LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE
ALONG COASTAL SE GEORGIA... OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS
TONIGHT. WE LOWERED LOW TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW
THE WARM ADVECTION. THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT
AS STRATUS COULD BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST
CONCERN IS INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME
STRONGER FOG MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
KCHS...WE MAINTAINED CONTINUITY WITH IFR CIGS UNTIL MIDDAY THEN
CIGS WILL BE CLOSE TO 1 KFT THIS AFTERNOON. STRATUS MAY BRIEFLY
SCATTER OUT AT TIMES THROUGH MID MORNING AND CONFIDENCE ON IFR
VERSUS MVFR THIS AFTERNOON IS LOW. THE PATTERN SUGGESTS IT COULD
REMAIN IFR WITH OCCASIONAL RAIN ANTICIPATED. TONIGHT...THE STRATUS
SHOULD BUILD DOWN OVERNIGHT WITH RAIN AND FOG AT TIMES LIKELY.
LIFR CIGS ARE POSSIBLE OVERNIGHT AND ESPECIALLY LATE AS THE LOW
LEVEL WIND FIELDS DIMINISH.

KSAV...MODELS FAIRLY CONSISTENT ON LOCKING IN IFR CIGS ALL DAY AND
AGAIN TONIGHT. THE SYNOPTIC PATTERN IS CERTAINLY FAVORABLE FOR THIS
TO OCCUR WITH A STRENGTHENING WEDGE INVERSION AND WARM AIR ADVECTION
PATTERN ATOP A COOL AND STABLE AIR MASS. WE FOLLOWED THIS GUIDANCE
AND PREVAILED LIGHT RAINS THIS MORNING. IT COULD RAIN LONGER INTO
THE DAY OR AT LEAST DRIZZLE. TONIGHT...CONDITIONS LOOK TO DETERIORATE
EVEN FURTHER WITH CIGS AT OR BELOW 500 FT WITH OCCASIONAL RAINS AND
A CHANCE FOR SOME FOG IF CIGS SETTLE RIGHT OFF THE SURFACE.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
THE NAM AND IT/S LOCAL VARIATION WERE USED TO HANDLE A VERY TRICKY
MARINE FORECAST THIS MORNING AS PINCHING GRADIENT INITIALLY EXTENDING
ALONG THE OUTER FRINGES OF OUR NEAR SHORE SOUTH CAROLINA WATERS
SOUTH INTO THE OUTER GEORGIA WATERS. OVERNIGHT WE RAISED A SMALL
CRAFT ADVISORY FOR GEORGIA WATERS 20-60 NM AS GRAYS REEF HAS BEEN
REPORTING A SOLID 19-20 KT WITH HIGHER GUSTS AND SEAS UP TO 5 FT.

AT SOME POINT TODAY WE MAY NEED TO CONSIDER AN ADVISORY WITHIN 20
NM OF THE COAST BUT IT LOOKS FAIRLY MARGINAL WITH 15-20 KT NE WINDS
AND 4-5 FT COVERING THE SITUATION FOR THE MOST PART. TONIGHT AS
THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE RIDES THE GULF
STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING ALONG THE CHARLESTON
COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE TONIGHT. MODEL PROGS
SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS HAVE NOT DEVELOPED BY
THIS EVENING....CHANCES ARE DECENT FOR SLIGHTLY DIMINISHED WINDS
AND SEAS AFTER MIDNIGHT. THERE MAY BE SOME LOWER VSBYS AT TIMES
TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD FRONT
THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT. SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE AS
THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY
BE NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS
GUST TO 30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS
TO 5-8 FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE
IMPROVING LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 211228
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
728 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN APPROACH
FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA WEDNESDAY
AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE WILL THEN SETTLE
OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
OUR DAMP AND COOL FORECAST IS ON TRACK THROUGH TONIGHT...THE CHANGES
WE MADE THIS MORNING WERE TO MAKE IT A BIT COOLER AND EVEN DAMPER
IN SOME LOCATIONS. ISENTROPIC ASCENT WILL CONTINUE TO STEEPEN AND
EXPAND OVER GEORGIA AND SOUTH CAROLINA TODAY. ANOTHER SHORT WAVE
TROUGH WILL LIFT FROM NORTH GEORGIA THIS MORNING...THROUGH THE
CAROLINAS TODAY WHILE THE AXIS OF THE BAROCLINIC ZONE REMAINS
ENTRENCHED FROM NORTH CENTRAL FLORIDA TO THE GULF STREAM TO OUR
EAST. OUR FORECAST AREA WILL BE IN THE GRIPS OF AN ANCHORED
SURFACE WEDGE PATTERN WHICH WILL REMAIN LOCKED IN UNDER PERIODS OF
LIGHT RAINS AND A NOSE OF WARMING TEMPS AT 925 MB. WE LOWERED
TEMPS TODAY ACROSS THE BOARD GIVEN OVERNIGHT SURFACE ANALYSIS AND
AN EMPHATICALLY COOLER SURFACE TEMP TREND PROGGED BY MANY OF THE
00Z MODELS. SOME AREAS MAY STRUGGLE TO HIT 50 DEGREES TODAY TO THE
NORTH OF I-16...WHILE RAINS HOLD TEMPS DOWN IN THE LOWER TO MID
50S IN AREAS SUCH AS DARIEN AND LUDOWICI GEORGIA.

FORECAST SOUNDINGS AND MODEL PROJECTIONS INDICATE MANY AREAS WILL SEE
MEASURABLE LIGHT RAINS TODAY WITH HIGHEST CONFIDENCE ACROSS THE SE HALF
OF THE FORECAST AREA GIVEN THE PROXIMITY TO LOWER CONDENSATION PRES
DEFICITS AND DEEPER MOISTURE FIELDS. POPS AVERAGE OUT IN THE LIKELY
CATEGORY TODAY...BUT RAINFALL AMOUNTS ON THE LIGHT SIDE ONCE AGAIN.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER SHORT
WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE. MODELS INDICATE
A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION WILL LIFT THROUGH THE
REGION OVERNIGHT AND THIS SHOULD NUDGE THE COASTAL FRONT WELL OFFSHORE
JUST A BIT CLOSER IN...BUT THE WEDGE WILL REMAIN STRONG AND INTACT
ALL AREAS. 1/2 INCH OR LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE
ALONG COASTAL SE GEORGIA... OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS
TONIGHT. WE LOWERED LOW TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW
THE WARM ADVECTION. THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT
AS STRATUS COULD BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST
CONCERN IS INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME
STRONGER FOG MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
KCHS...WE MAINTAINED CONTINUITY WITH IFR CIGS UNTIL MIDDAY THEN
CIGS WILL BE CLOSE TO 1 KFT THIS AFTERNOON. STRATUS MAY BRIEFLY
SCATTER OUT AT TIMES THROUGH MID MORNING AND CONFIDENCE ON IFR
VERSUS MVFR THIS AFTERNOON IS LOW. THE PATTERN SUGGESTS IT COULD
REMAIN IFR WITH OCCASIONAL RAIN ANTICIPATED. TONIGHT...THE STRATUS
SHOULD BUILD DOWN OVERNIGHT WITH RAIN AND FOG AT TIMES LIKELY.
LIFR CIGS ARE POSSIBLE OVERNIGHT AND ESPECIALLY LATE AS THE LOW
LEVEL WIND FIELDS DIMINISH.

KSAV...MODELS FAIRLY CONSISTENT ON LOCKING IN IFR CIGS ALL DAY AND
AGAIN TONIGHT. THE SYNOPTIC PATTERN IS CERTAINLY FAVORABLE FOR THIS
TO OCCUR WITH A STRENGTHENING WEDGE INVERSION AND WARM AIR ADVECTION
PATTERN ATOP A COOL AND STABLE AIR MASS. WE FOLLOWED THIS GUIDANCE
AND PREVAILED LIGHT RAINS THIS MORNING. IT COULD RAIN LONGER INTO
THE DAY OR AT LEAST DRIZZLE. TONIGHT...CONDITIONS LOOK TO DETERIORATE
EVEN FURTHER WITH CIGS AT OR BELOW 500 FT WITH OCCASIONAL RAINS AND
A CHANCE FOR SOME FOG IF CIGS SETTLE RIGHT OFF THE SURFACE.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
THE NAM AND IT/S LOCAL VARIATION WERE USED TO HANDLE A VERY TRICKY
MARINE FORECAST THIS MORNING AS PINCHING GRADIENT INITIALLY EXTENDING
ALONG THE OUTER FRINGES OF OUR NEAR SHORE SOUTH CAROLINA WATERS
SOUTH INTO THE OUTER GEORGIA WATERS. OVERNIGHT WE RAISED A SMALL
CRAFT ADVISORY FOR GEORGIA WATERS 20-60 NM AS GRAYS REEF HAS BEEN
REPORTING A SOLID 19-20 KT WITH HIGHER GUSTS AND SEAS UP TO 5 FT.

AT SOME POINT TODAY WE MAY NEED TO CONSIDER AN ADVISORY WITHIN 20
NM OF THE COAST BUT IT LOOKS FAIRLY MARGINAL WITH 15-20 KT NE WINDS
AND 4-5 FT COVERING THE SITUATION FOR THE MOST PART. TONIGHT AS
THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE RIDES THE GULF
STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING ALONG THE CHARLESTON
COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE TONIGHT. MODEL PROGS
SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS HAVE NOT DEVELOPED BY
THIS EVENING....CHANCES ARE DECENT FOR SLIGHTLY DIMINISHED WINDS
AND SEAS AFTER MIDNIGHT. THERE MAY BE SOME LOWER VSBYS AT TIMES
TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD FRONT
THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT. SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE AS
THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY
BE NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS
GUST TO 30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS
TO 5-8 FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE
IMPROVING LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 211228
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
728 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN APPROACH
FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA WEDNESDAY
AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE WILL THEN SETTLE
OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
OUR DAMP AND COOL FORECAST IS ON TRACK THROUGH TONIGHT...THE CHANGES
WE MADE THIS MORNING WERE TO MAKE IT A BIT COOLER AND EVEN DAMPER
IN SOME LOCATIONS. ISENTROPIC ASCENT WILL CONTINUE TO STEEPEN AND
EXPAND OVER GEORGIA AND SOUTH CAROLINA TODAY. ANOTHER SHORT WAVE
TROUGH WILL LIFT FROM NORTH GEORGIA THIS MORNING...THROUGH THE
CAROLINAS TODAY WHILE THE AXIS OF THE BAROCLINIC ZONE REMAINS
ENTRENCHED FROM NORTH CENTRAL FLORIDA TO THE GULF STREAM TO OUR
EAST. OUR FORECAST AREA WILL BE IN THE GRIPS OF AN ANCHORED
SURFACE WEDGE PATTERN WHICH WILL REMAIN LOCKED IN UNDER PERIODS OF
LIGHT RAINS AND A NOSE OF WARMING TEMPS AT 925 MB. WE LOWERED
TEMPS TODAY ACROSS THE BOARD GIVEN OVERNIGHT SURFACE ANALYSIS AND
AN EMPHATICALLY COOLER SURFACE TEMP TREND PROGGED BY MANY OF THE
00Z MODELS. SOME AREAS MAY STRUGGLE TO HIT 50 DEGREES TODAY TO THE
NORTH OF I-16...WHILE RAINS HOLD TEMPS DOWN IN THE LOWER TO MID
50S IN AREAS SUCH AS DARIEN AND LUDOWICI GEORGIA.

FORECAST SOUNDINGS AND MODEL PROJECTIONS INDICATE MANY AREAS WILL SEE
MEASURABLE LIGHT RAINS TODAY WITH HIGHEST CONFIDENCE ACROSS THE SE HALF
OF THE FORECAST AREA GIVEN THE PROXIMITY TO LOWER CONDENSATION PRES
DEFICITS AND DEEPER MOISTURE FIELDS. POPS AVERAGE OUT IN THE LIKELY
CATEGORY TODAY...BUT RAINFALL AMOUNTS ON THE LIGHT SIDE ONCE AGAIN.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER SHORT
WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE. MODELS INDICATE
A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION WILL LIFT THROUGH THE
REGION OVERNIGHT AND THIS SHOULD NUDGE THE COASTAL FRONT WELL OFFSHORE
JUST A BIT CLOSER IN...BUT THE WEDGE WILL REMAIN STRONG AND INTACT
ALL AREAS. 1/2 INCH OR LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE
ALONG COASTAL SE GEORGIA... OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS
TONIGHT. WE LOWERED LOW TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW
THE WARM ADVECTION. THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT
AS STRATUS COULD BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST
CONCERN IS INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME
STRONGER FOG MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
KCHS...WE MAINTAINED CONTINUITY WITH IFR CIGS UNTIL MIDDAY THEN
CIGS WILL BE CLOSE TO 1 KFT THIS AFTERNOON. STRATUS MAY BRIEFLY
SCATTER OUT AT TIMES THROUGH MID MORNING AND CONFIDENCE ON IFR
VERSUS MVFR THIS AFTERNOON IS LOW. THE PATTERN SUGGESTS IT COULD
REMAIN IFR WITH OCCASIONAL RAIN ANTICIPATED. TONIGHT...THE STRATUS
SHOULD BUILD DOWN OVERNIGHT WITH RAIN AND FOG AT TIMES LIKELY.
LIFR CIGS ARE POSSIBLE OVERNIGHT AND ESPECIALLY LATE AS THE LOW
LEVEL WIND FIELDS DIMINISH.

KSAV...MODELS FAIRLY CONSISTENT ON LOCKING IN IFR CIGS ALL DAY AND
AGAIN TONIGHT. THE SYNOPTIC PATTERN IS CERTAINLY FAVORABLE FOR THIS
TO OCCUR WITH A STRENGTHENING WEDGE INVERSION AND WARM AIR ADVECTION
PATTERN ATOP A COOL AND STABLE AIR MASS. WE FOLLOWED THIS GUIDANCE
AND PREVAILED LIGHT RAINS THIS MORNING. IT COULD RAIN LONGER INTO
THE DAY OR AT LEAST DRIZZLE. TONIGHT...CONDITIONS LOOK TO DETERIORATE
EVEN FURTHER WITH CIGS AT OR BELOW 500 FT WITH OCCASIONAL RAINS AND
A CHANCE FOR SOME FOG IF CIGS SETTLE RIGHT OFF THE SURFACE.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
THE NAM AND IT/S LOCAL VARIATION WERE USED TO HANDLE A VERY TRICKY
MARINE FORECAST THIS MORNING AS PINCHING GRADIENT INITIALLY EXTENDING
ALONG THE OUTER FRINGES OF OUR NEAR SHORE SOUTH CAROLINA WATERS
SOUTH INTO THE OUTER GEORGIA WATERS. OVERNIGHT WE RAISED A SMALL
CRAFT ADVISORY FOR GEORGIA WATERS 20-60 NM AS GRAYS REEF HAS BEEN
REPORTING A SOLID 19-20 KT WITH HIGHER GUSTS AND SEAS UP TO 5 FT.

AT SOME POINT TODAY WE MAY NEED TO CONSIDER AN ADVISORY WITHIN 20
NM OF THE COAST BUT IT LOOKS FAIRLY MARGINAL WITH 15-20 KT NE WINDS
AND 4-5 FT COVERING THE SITUATION FOR THE MOST PART. TONIGHT AS
THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE RIDES THE GULF
STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING ALONG THE CHARLESTON
COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE TONIGHT. MODEL PROGS
SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS HAVE NOT DEVELOPED BY
THIS EVENING....CHANCES ARE DECENT FOR SLIGHTLY DIMINISHED WINDS
AND SEAS AFTER MIDNIGHT. THERE MAY BE SOME LOWER VSBYS AT TIMES
TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD FRONT
THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT. SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE AS
THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY
BE NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS
GUST TO 30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS
TO 5-8 FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE
IMPROVING LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 211228
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
728 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN APPROACH
FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA WEDNESDAY
AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE WILL THEN SETTLE
OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
OUR DAMP AND COOL FORECAST IS ON TRACK THROUGH TONIGHT...THE CHANGES
WE MADE THIS MORNING WERE TO MAKE IT A BIT COOLER AND EVEN DAMPER
IN SOME LOCATIONS. ISENTROPIC ASCENT WILL CONTINUE TO STEEPEN AND
EXPAND OVER GEORGIA AND SOUTH CAROLINA TODAY. ANOTHER SHORT WAVE
TROUGH WILL LIFT FROM NORTH GEORGIA THIS MORNING...THROUGH THE
CAROLINAS TODAY WHILE THE AXIS OF THE BAROCLINIC ZONE REMAINS
ENTRENCHED FROM NORTH CENTRAL FLORIDA TO THE GULF STREAM TO OUR
EAST. OUR FORECAST AREA WILL BE IN THE GRIPS OF AN ANCHORED
SURFACE WEDGE PATTERN WHICH WILL REMAIN LOCKED IN UNDER PERIODS OF
LIGHT RAINS AND A NOSE OF WARMING TEMPS AT 925 MB. WE LOWERED
TEMPS TODAY ACROSS THE BOARD GIVEN OVERNIGHT SURFACE ANALYSIS AND
AN EMPHATICALLY COOLER SURFACE TEMP TREND PROGGED BY MANY OF THE
00Z MODELS. SOME AREAS MAY STRUGGLE TO HIT 50 DEGREES TODAY TO THE
NORTH OF I-16...WHILE RAINS HOLD TEMPS DOWN IN THE LOWER TO MID
50S IN AREAS SUCH AS DARIEN AND LUDOWICI GEORGIA.

FORECAST SOUNDINGS AND MODEL PROJECTIONS INDICATE MANY AREAS WILL SEE
MEASURABLE LIGHT RAINS TODAY WITH HIGHEST CONFIDENCE ACROSS THE SE HALF
OF THE FORECAST AREA GIVEN THE PROXIMITY TO LOWER CONDENSATION PRES
DEFICITS AND DEEPER MOISTURE FIELDS. POPS AVERAGE OUT IN THE LIKELY
CATEGORY TODAY...BUT RAINFALL AMOUNTS ON THE LIGHT SIDE ONCE AGAIN.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER SHORT
WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE. MODELS INDICATE
A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION WILL LIFT THROUGH THE
REGION OVERNIGHT AND THIS SHOULD NUDGE THE COASTAL FRONT WELL OFFSHORE
JUST A BIT CLOSER IN...BUT THE WEDGE WILL REMAIN STRONG AND INTACT
ALL AREAS. 1/2 INCH OR LOCALLY HIGHER RAINFALL AMOUNTS ARE POSSIBLE
ALONG COASTAL SE GEORGIA... OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS
TONIGHT. WE LOWERED LOW TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW
THE WARM ADVECTION. THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT
AS STRATUS COULD BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST
CONCERN IS INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME
STRONGER FOG MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
KCHS...WE MAINTAINED CONTINUITY WITH IFR CIGS UNTIL MIDDAY THEN
CIGS WILL BE CLOSE TO 1 KFT THIS AFTERNOON. STRATUS MAY BRIEFLY
SCATTER OUT AT TIMES THROUGH MID MORNING AND CONFIDENCE ON IFR
VERSUS MVFR THIS AFTERNOON IS LOW. THE PATTERN SUGGESTS IT COULD
REMAIN IFR WITH OCCASIONAL RAIN ANTICIPATED. TONIGHT...THE STRATUS
SHOULD BUILD DOWN OVERNIGHT WITH RAIN AND FOG AT TIMES LIKELY.
LIFR CIGS ARE POSSIBLE OVERNIGHT AND ESPECIALLY LATE AS THE LOW
LEVEL WIND FIELDS DIMINISH.

KSAV...MODELS FAIRLY CONSISTENT ON LOCKING IN IFR CIGS ALL DAY AND
AGAIN TONIGHT. THE SYNOPTIC PATTERN IS CERTAINLY FAVORABLE FOR THIS
TO OCCUR WITH A STRENGTHENING WEDGE INVERSION AND WARM AIR ADVECTION
PATTERN ATOP A COOL AND STABLE AIR MASS. WE FOLLOWED THIS GUIDANCE
AND PREVAILED LIGHT RAINS THIS MORNING. IT COULD RAIN LONGER INTO
THE DAY OR AT LEAST DRIZZLE. TONIGHT...CONDITIONS LOOK TO DETERIORATE
EVEN FURTHER WITH CIGS AT OR BELOW 500 FT WITH OCCASIONAL RAINS AND
A CHANCE FOR SOME FOG IF CIGS SETTLE RIGHT OFF THE SURFACE.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
THE NAM AND IT/S LOCAL VARIATION WERE USED TO HANDLE A VERY TRICKY
MARINE FORECAST THIS MORNING AS PINCHING GRADIENT INITIALLY EXTENDING
ALONG THE OUTER FRINGES OF OUR NEAR SHORE SOUTH CAROLINA WATERS
SOUTH INTO THE OUTER GEORGIA WATERS. OVERNIGHT WE RAISED A SMALL
CRAFT ADVISORY FOR GEORGIA WATERS 20-60 NM AS GRAYS REEF HAS BEEN
REPORTING A SOLID 19-20 KT WITH HIGHER GUSTS AND SEAS UP TO 5 FT.

AT SOME POINT TODAY WE MAY NEED TO CONSIDER AN ADVISORY WITHIN 20
NM OF THE COAST BUT IT LOOKS FAIRLY MARGINAL WITH 15-20 KT NE WINDS
AND 4-5 FT COVERING THE SITUATION FOR THE MOST PART. TONIGHT AS
THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE RIDES THE GULF
STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING ALONG THE CHARLESTON
COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE TONIGHT. MODEL PROGS
SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS HAVE NOT DEVELOPED BY
THIS EVENING....CHANCES ARE DECENT FOR SLIGHTLY DIMINISHED WINDS
AND SEAS AFTER MIDNIGHT. THERE MAY BE SOME LOWER VSBYS AT TIMES
TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD FRONT
THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT. SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE AS
THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY
BE NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS
GUST TO 30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS
TO 5-8 FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE
IMPROVING LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 210947
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
447 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
APPROACH FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA
WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE
WILL THEN SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...DAMP AND COOL WEATHER OVERNIGHT WITH A FEW AREAS ACROSS SE
GEORGIA SEEING LIGHT RAINS WITH ALL LOCATIONS UNDER FULL CLOUD COVER
AND SOME PERIODIC SPRINKLES. TEMPS HAVE BEEN IN THE 45-50 DEGREE RANGE
OVERNIGHT. WEAK UPPER FORCING WAS NOTED ACROSS OUR AREA IN THE BROAD
ENTRANCE JET ENTRANCE REGION BELOW THE PATH OF A 135 KT UPPER JET
FROM UPSTATE SOUTH CAROLINA TO THE WESTERN ATLC EAST OF THE OUTER
BANKS. ISENTROPIC ASCENT ALONG THE 295K PRES SURFACE WAS INCREASING
OVER SOUTH GEORGIA AND REGIONAL RADARS SHOW LIGHT RAIN INCREASING.
WE HAVE LIKELY/CATEGORICAL POPS GOING TO THE SOUTH OF I-16 WITH
CHANCE POPS ELSEWHERE THE NEXT FEW HOURS. WE KEPT SOME PATCHY FOG
MENTIONS BUT STRATUS LAYERS COULD BUILD DOWN OVER INLAND GEORGIA
ZONES NEAR DAYBREAK. WITH THE BEHAVIOR OF THE STRATUS AT 4 AM...WE
ARE NOT ANTICIPATING DENSE FOG AT THIS TIME.

OUR DAMP AND COOL FORECAST ON TRACK THROUGH TONIGHT...THE CHANGES
WE MADE THIS MORNING WERE TO MAKE IT A BIT COOLER AND EVEN DAMPER
IN SOME LOCATIONS. ISENTROPIC ASCENT WILL CONTINUE TO STEEPEN AND
EXPAND OVER GEORGIA AND SOUTH CAROLINA TODAY. ANOTHER SHORT WAVE
TROUGH WILL LIFT FROM NORTH GEORGIA THIS MORNING...THROUGH THE
CAROLINAS TODAY WHILE THE AXIS OF THE BAROCLINIC ZONE REMAINS
ENTRENCHED FROM NORTH CENTRAL FLORIDA TO THE GULF STREAM TO OUR
EAST. OUR FORECAST AREA WILL BE IN THE GRIPS OF AN ANCHORED
SURFACE WEDGE PATTERN WHICH WILL REMAIN LOCKED IN UNDER PERIODS OF
LIGHT RAINS AND A NOSE OF WARMING TEMPS AT 925 MB. WE LOWERED
TEMPS TODAY ACROSS THE BOARD GIVEN OVERNIGHT SURFACE ANALYSIS AND
AN EMPHATICALLY COOLER SURFACE TEMP TREND PROGGED BY MANY OF THE
00Z MODELS. SOME AREAS INLAND MAY STRUGGLE TO HIT 50 DEGREES TODAY
TO THE NORTH OF I-16...WHILE RAINS HOLD TEMPS DOWN IN THE LOWER
TO MID 50S IN AREAS SUCH AS DARIEN AND LUDOWICI GEORGIA.

FORECAST SOUNDINGS AND MODEL PROJECTIONS INDICATE MANY AREAS WILL
SEE MEASURABLE LIGHT RAINS TODAY WITH HIGHEST CONFIDENCE ACROSS THE
SE HALF OF THE FORECAST AREA GIVEN THE PROXIMITY TO LOWER CONDENSATION
PRES DEFICITS AND DEEPER MOISTURE FIELDS. POPS AVERAGE OUT IN THE
LIKELY CATEGORY TODAY...BUT RAINFALL AMOUNTS ON THE LIGHT SIDE ONCE
AGAIN.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER
SHORT WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE.
MODELS INDICATE A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION
WILL LIFT THROUGH THE REGION OVERNIGHT AND THIS SHOULD NUDGE THE
COASTAL FRONT WELL OFFSHORE JUST A BIT CLOSER IN...BUT THE WEDGE
WILL REMAIN STRONG AND INTACT ALL AREAS. 1/2 INCH OR LOCALLY
HIGHER RAINFALL AMOUNTS ARE POSSIBLE ALONG COASTAL SE GEORGIA...
OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS TONIGHT. WE LOWERED LOW
TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW THE WARM ADVECTION.
THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT AS STRATUS COULD
BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST CONCERN IS
INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME STRONGER FOG
MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
IFR CIGS SHOULD REMAIN IN PLACE OVERNIGHT WITH SMALL CHANCES OF LIFR
CIGS OR LOW END MVFR CIGS ON EITHER END. A FEW PERIODS OF LIGHT RAIN
AND EVEN SOME DRIZZLE SHOULD CONTINUE. LATEST SOUNDINGS AT KSAV SHOW
IFR CIGS MAY REMAIN LOCKED IN THROUGH THE TAF CYCLE AS RAINFALL
APPEARS LIKELY AND THE WEDGE INVERSION QUITE STRONG. AT KCHS...
MODELS SHOW A DECENT CHANCE THAT CIGS LIFT INTO LOW END MVFR THIS
AFTERNOON BEFORE FALLING TO IFR AGAIN LATE DAY OR EARLY THIS EVENING.
TIMING PERIODS OF LIGHT RAIN AT EITHER TERMINAL IS VERY DIFFICULT
TO PIN DOWN AT THIS TIME.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
THE NAM AND IT/S LOCAL VARIATION WERE USED TO HANDLE A VERY TRICKY
MARINE FORECAST THIS MORNING AS PINCHING GRADIENT INITIALLY EXTENDING
ALONG THE OUTER FRINGES OF OUR NEAR SHORE SOUTH CAROLINA WATERS
SOUTH INTO THE OUTER GEORGIA WATERS. OVERNIGHT WE RAISED A SMALL
CRAFT ADVISORY FOR GEORGIA WATERS 20-60 NM AS GRAYS REEF HAS BEEN
REPORTING A SOLID 19-20 KT WITH HIGHER GUSTS AND SEAS UP TO 5 FT.

AT SOME POINT TODAY WE MAY NEED TO CONSIDER AN ADVISORY WITHIN 20
NM OF THE COAST BUT IT LOOKS FAIRLY MARGINAL WITH 15-20 KT NE WINDS
AND 4-5 FT COVERING THE SITUATION FOR THE MOST PART. TONIGHT AS
THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE RIDES THE GULF
STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING ALONG THE CHARLESTON
COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE TONIGHT. MODEL PROGS
SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS HAVE NOT DEVELOPED BY
THIS EVENING....CHANCES ARE DECENT FOR SLIGHTLY DIMINISHED WINDS
AND SEAS AFTER MIDNIGHT. THERE MAY BE SOME LOWER VSBYS AT TIMES
TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD
FRONT THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF
THE FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY
FLOW. AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY
LEVELS NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS
AHEAD OF THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE
AS THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY BE
NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS GUST TO
30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS TO 5-8
FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE IMPROVING
LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS.
WINDS/SEAS SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL
WATERS AROUND DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH
LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 210947
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
447 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
APPROACH FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA
WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE
WILL THEN SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...DAMP AND COOL WEATHER OVERNIGHT WITH A FEW AREAS ACROSS SE
GEORGIA SEEING LIGHT RAINS WITH ALL LOCATIONS UNDER FULL CLOUD COVER
AND SOME PERIODIC SPRINKLES. TEMPS HAVE BEEN IN THE 45-50 DEGREE RANGE
OVERNIGHT. WEAK UPPER FORCING WAS NOTED ACROSS OUR AREA IN THE BROAD
ENTRANCE JET ENTRANCE REGION BELOW THE PATH OF A 135 KT UPPER JET
FROM UPSTATE SOUTH CAROLINA TO THE WESTERN ATLC EAST OF THE OUTER
BANKS. ISENTROPIC ASCENT ALONG THE 295K PRES SURFACE WAS INCREASING
OVER SOUTH GEORGIA AND REGIONAL RADARS SHOW LIGHT RAIN INCREASING.
WE HAVE LIKELY/CATEGORICAL POPS GOING TO THE SOUTH OF I-16 WITH
CHANCE POPS ELSEWHERE THE NEXT FEW HOURS. WE KEPT SOME PATCHY FOG
MENTIONS BUT STRATUS LAYERS COULD BUILD DOWN OVER INLAND GEORGIA
ZONES NEAR DAYBREAK. WITH THE BEHAVIOR OF THE STRATUS AT 4 AM...WE
ARE NOT ANTICIPATING DENSE FOG AT THIS TIME.

OUR DAMP AND COOL FORECAST ON TRACK THROUGH TONIGHT...THE CHANGES
WE MADE THIS MORNING WERE TO MAKE IT A BIT COOLER AND EVEN DAMPER
IN SOME LOCATIONS. ISENTROPIC ASCENT WILL CONTINUE TO STEEPEN AND
EXPAND OVER GEORGIA AND SOUTH CAROLINA TODAY. ANOTHER SHORT WAVE
TROUGH WILL LIFT FROM NORTH GEORGIA THIS MORNING...THROUGH THE
CAROLINAS TODAY WHILE THE AXIS OF THE BAROCLINIC ZONE REMAINS
ENTRENCHED FROM NORTH CENTRAL FLORIDA TO THE GULF STREAM TO OUR
EAST. OUR FORECAST AREA WILL BE IN THE GRIPS OF AN ANCHORED
SURFACE WEDGE PATTERN WHICH WILL REMAIN LOCKED IN UNDER PERIODS OF
LIGHT RAINS AND A NOSE OF WARMING TEMPS AT 925 MB. WE LOWERED
TEMPS TODAY ACROSS THE BOARD GIVEN OVERNIGHT SURFACE ANALYSIS AND
AN EMPHATICALLY COOLER SURFACE TEMP TREND PROGGED BY MANY OF THE
00Z MODELS. SOME AREAS INLAND MAY STRUGGLE TO HIT 50 DEGREES TODAY
TO THE NORTH OF I-16...WHILE RAINS HOLD TEMPS DOWN IN THE LOWER
TO MID 50S IN AREAS SUCH AS DARIEN AND LUDOWICI GEORGIA.

FORECAST SOUNDINGS AND MODEL PROJECTIONS INDICATE MANY AREAS WILL
SEE MEASURABLE LIGHT RAINS TODAY WITH HIGHEST CONFIDENCE ACROSS THE
SE HALF OF THE FORECAST AREA GIVEN THE PROXIMITY TO LOWER CONDENSATION
PRES DEFICITS AND DEEPER MOISTURE FIELDS. POPS AVERAGE OUT IN THE
LIKELY CATEGORY TODAY...BUT RAINFALL AMOUNTS ON THE LIGHT SIDE ONCE
AGAIN.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER
SHORT WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE.
MODELS INDICATE A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION
WILL LIFT THROUGH THE REGION OVERNIGHT AND THIS SHOULD NUDGE THE
COASTAL FRONT WELL OFFSHORE JUST A BIT CLOSER IN...BUT THE WEDGE
WILL REMAIN STRONG AND INTACT ALL AREAS. 1/2 INCH OR LOCALLY
HIGHER RAINFALL AMOUNTS ARE POSSIBLE ALONG COASTAL SE GEORGIA...
OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS TONIGHT. WE LOWERED LOW
TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW THE WARM ADVECTION.
THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT AS STRATUS COULD
BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST CONCERN IS
INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME STRONGER FOG
MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
IFR CIGS SHOULD REMAIN IN PLACE OVERNIGHT WITH SMALL CHANCES OF LIFR
CIGS OR LOW END MVFR CIGS ON EITHER END. A FEW PERIODS OF LIGHT RAIN
AND EVEN SOME DRIZZLE SHOULD CONTINUE. LATEST SOUNDINGS AT KSAV SHOW
IFR CIGS MAY REMAIN LOCKED IN THROUGH THE TAF CYCLE AS RAINFALL
APPEARS LIKELY AND THE WEDGE INVERSION QUITE STRONG. AT KCHS...
MODELS SHOW A DECENT CHANCE THAT CIGS LIFT INTO LOW END MVFR THIS
AFTERNOON BEFORE FALLING TO IFR AGAIN LATE DAY OR EARLY THIS EVENING.
TIMING PERIODS OF LIGHT RAIN AT EITHER TERMINAL IS VERY DIFFICULT
TO PIN DOWN AT THIS TIME.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
THE NAM AND IT/S LOCAL VARIATION WERE USED TO HANDLE A VERY TRICKY
MARINE FORECAST THIS MORNING AS PINCHING GRADIENT INITIALLY EXTENDING
ALONG THE OUTER FRINGES OF OUR NEAR SHORE SOUTH CAROLINA WATERS
SOUTH INTO THE OUTER GEORGIA WATERS. OVERNIGHT WE RAISED A SMALL
CRAFT ADVISORY FOR GEORGIA WATERS 20-60 NM AS GRAYS REEF HAS BEEN
REPORTING A SOLID 19-20 KT WITH HIGHER GUSTS AND SEAS UP TO 5 FT.

AT SOME POINT TODAY WE MAY NEED TO CONSIDER AN ADVISORY WITHIN 20
NM OF THE COAST BUT IT LOOKS FAIRLY MARGINAL WITH 15-20 KT NE WINDS
AND 4-5 FT COVERING THE SITUATION FOR THE MOST PART. TONIGHT AS
THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE RIDES THE GULF
STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING ALONG THE CHARLESTON
COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE TONIGHT. MODEL PROGS
SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS HAVE NOT DEVELOPED BY
THIS EVENING....CHANCES ARE DECENT FOR SLIGHTLY DIMINISHED WINDS
AND SEAS AFTER MIDNIGHT. THERE MAY BE SOME LOWER VSBYS AT TIMES
TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD
FRONT THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF
THE FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY
FLOW. AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY
LEVELS NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS
AHEAD OF THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE
AS THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY BE
NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS GUST TO
30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS TO 5-8
FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE IMPROVING
LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS.
WINDS/SEAS SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL
WATERS AROUND DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH
LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 210947
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
447 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
APPROACH FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA
WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE
WILL THEN SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...DAMP AND COOL WEATHER OVERNIGHT WITH A FEW AREAS ACROSS SE
GEORGIA SEEING LIGHT RAINS WITH ALL LOCATIONS UNDER FULL CLOUD COVER
AND SOME PERIODIC SPRINKLES. TEMPS HAVE BEEN IN THE 45-50 DEGREE RANGE
OVERNIGHT. WEAK UPPER FORCING WAS NOTED ACROSS OUR AREA IN THE BROAD
ENTRANCE JET ENTRANCE REGION BELOW THE PATH OF A 135 KT UPPER JET
FROM UPSTATE SOUTH CAROLINA TO THE WESTERN ATLC EAST OF THE OUTER
BANKS. ISENTROPIC ASCENT ALONG THE 295K PRES SURFACE WAS INCREASING
OVER SOUTH GEORGIA AND REGIONAL RADARS SHOW LIGHT RAIN INCREASING.
WE HAVE LIKELY/CATEGORICAL POPS GOING TO THE SOUTH OF I-16 WITH
CHANCE POPS ELSEWHERE THE NEXT FEW HOURS. WE KEPT SOME PATCHY FOG
MENTIONS BUT STRATUS LAYERS COULD BUILD DOWN OVER INLAND GEORGIA
ZONES NEAR DAYBREAK. WITH THE BEHAVIOR OF THE STRATUS AT 4 AM...WE
ARE NOT ANTICIPATING DENSE FOG AT THIS TIME.

OUR DAMP AND COOL FORECAST ON TRACK THROUGH TONIGHT...THE CHANGES
WE MADE THIS MORNING WERE TO MAKE IT A BIT COOLER AND EVEN DAMPER
IN SOME LOCATIONS. ISENTROPIC ASCENT WILL CONTINUE TO STEEPEN AND
EXPAND OVER GEORGIA AND SOUTH CAROLINA TODAY. ANOTHER SHORT WAVE
TROUGH WILL LIFT FROM NORTH GEORGIA THIS MORNING...THROUGH THE
CAROLINAS TODAY WHILE THE AXIS OF THE BAROCLINIC ZONE REMAINS
ENTRENCHED FROM NORTH CENTRAL FLORIDA TO THE GULF STREAM TO OUR
EAST. OUR FORECAST AREA WILL BE IN THE GRIPS OF AN ANCHORED
SURFACE WEDGE PATTERN WHICH WILL REMAIN LOCKED IN UNDER PERIODS OF
LIGHT RAINS AND A NOSE OF WARMING TEMPS AT 925 MB. WE LOWERED
TEMPS TODAY ACROSS THE BOARD GIVEN OVERNIGHT SURFACE ANALYSIS AND
AN EMPHATICALLY COOLER SURFACE TEMP TREND PROGGED BY MANY OF THE
00Z MODELS. SOME AREAS INLAND MAY STRUGGLE TO HIT 50 DEGREES TODAY
TO THE NORTH OF I-16...WHILE RAINS HOLD TEMPS DOWN IN THE LOWER
TO MID 50S IN AREAS SUCH AS DARIEN AND LUDOWICI GEORGIA.

FORECAST SOUNDINGS AND MODEL PROJECTIONS INDICATE MANY AREAS WILL
SEE MEASURABLE LIGHT RAINS TODAY WITH HIGHEST CONFIDENCE ACROSS THE
SE HALF OF THE FORECAST AREA GIVEN THE PROXIMITY TO LOWER CONDENSATION
PRES DEFICITS AND DEEPER MOISTURE FIELDS. POPS AVERAGE OUT IN THE
LIKELY CATEGORY TODAY...BUT RAINFALL AMOUNTS ON THE LIGHT SIDE ONCE
AGAIN.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER
SHORT WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE.
MODELS INDICATE A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION
WILL LIFT THROUGH THE REGION OVERNIGHT AND THIS SHOULD NUDGE THE
COASTAL FRONT WELL OFFSHORE JUST A BIT CLOSER IN...BUT THE WEDGE
WILL REMAIN STRONG AND INTACT ALL AREAS. 1/2 INCH OR LOCALLY
HIGHER RAINFALL AMOUNTS ARE POSSIBLE ALONG COASTAL SE GEORGIA...
OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS TONIGHT. WE LOWERED LOW
TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW THE WARM ADVECTION.
THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT AS STRATUS COULD
BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST CONCERN IS
INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME STRONGER FOG
MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
IFR CIGS SHOULD REMAIN IN PLACE OVERNIGHT WITH SMALL CHANCES OF LIFR
CIGS OR LOW END MVFR CIGS ON EITHER END. A FEW PERIODS OF LIGHT RAIN
AND EVEN SOME DRIZZLE SHOULD CONTINUE. LATEST SOUNDINGS AT KSAV SHOW
IFR CIGS MAY REMAIN LOCKED IN THROUGH THE TAF CYCLE AS RAINFALL
APPEARS LIKELY AND THE WEDGE INVERSION QUITE STRONG. AT KCHS...
MODELS SHOW A DECENT CHANCE THAT CIGS LIFT INTO LOW END MVFR THIS
AFTERNOON BEFORE FALLING TO IFR AGAIN LATE DAY OR EARLY THIS EVENING.
TIMING PERIODS OF LIGHT RAIN AT EITHER TERMINAL IS VERY DIFFICULT
TO PIN DOWN AT THIS TIME.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
THE NAM AND IT/S LOCAL VARIATION WERE USED TO HANDLE A VERY TRICKY
MARINE FORECAST THIS MORNING AS PINCHING GRADIENT INITIALLY EXTENDING
ALONG THE OUTER FRINGES OF OUR NEAR SHORE SOUTH CAROLINA WATERS
SOUTH INTO THE OUTER GEORGIA WATERS. OVERNIGHT WE RAISED A SMALL
CRAFT ADVISORY FOR GEORGIA WATERS 20-60 NM AS GRAYS REEF HAS BEEN
REPORTING A SOLID 19-20 KT WITH HIGHER GUSTS AND SEAS UP TO 5 FT.

AT SOME POINT TODAY WE MAY NEED TO CONSIDER AN ADVISORY WITHIN 20
NM OF THE COAST BUT IT LOOKS FAIRLY MARGINAL WITH 15-20 KT NE WINDS
AND 4-5 FT COVERING THE SITUATION FOR THE MOST PART. TONIGHT AS
THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE RIDES THE GULF
STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING ALONG THE CHARLESTON
COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE TONIGHT. MODEL PROGS
SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS HAVE NOT DEVELOPED BY
THIS EVENING....CHANCES ARE DECENT FOR SLIGHTLY DIMINISHED WINDS
AND SEAS AFTER MIDNIGHT. THERE MAY BE SOME LOWER VSBYS AT TIMES
TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD
FRONT THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF
THE FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY
FLOW. AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY
LEVELS NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS
AHEAD OF THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE
AS THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY BE
NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS GUST TO
30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS TO 5-8
FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE IMPROVING
LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS.
WINDS/SEAS SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL
WATERS AROUND DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH
LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 210947
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
447 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED TODAY THROUGH TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL THEN
APPROACH FROM THE WEST ON WEDNESDAY...THEN SHIFT THROUGH THE AREA
WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT. DRY HIGH PRESSURE
WILL THEN SETTLE OVER THE SOUTHEAST INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...DAMP AND COOL WEATHER OVERNIGHT WITH A FEW AREAS ACROSS SE
GEORGIA SEEING LIGHT RAINS WITH ALL LOCATIONS UNDER FULL CLOUD COVER
AND SOME PERIODIC SPRINKLES. TEMPS HAVE BEEN IN THE 45-50 DEGREE RANGE
OVERNIGHT. WEAK UPPER FORCING WAS NOTED ACROSS OUR AREA IN THE BROAD
ENTRANCE JET ENTRANCE REGION BELOW THE PATH OF A 135 KT UPPER JET
FROM UPSTATE SOUTH CAROLINA TO THE WESTERN ATLC EAST OF THE OUTER
BANKS. ISENTROPIC ASCENT ALONG THE 295K PRES SURFACE WAS INCREASING
OVER SOUTH GEORGIA AND REGIONAL RADARS SHOW LIGHT RAIN INCREASING.
WE HAVE LIKELY/CATEGORICAL POPS GOING TO THE SOUTH OF I-16 WITH
CHANCE POPS ELSEWHERE THE NEXT FEW HOURS. WE KEPT SOME PATCHY FOG
MENTIONS BUT STRATUS LAYERS COULD BUILD DOWN OVER INLAND GEORGIA
ZONES NEAR DAYBREAK. WITH THE BEHAVIOR OF THE STRATUS AT 4 AM...WE
ARE NOT ANTICIPATING DENSE FOG AT THIS TIME.

OUR DAMP AND COOL FORECAST ON TRACK THROUGH TONIGHT...THE CHANGES
WE MADE THIS MORNING WERE TO MAKE IT A BIT COOLER AND EVEN DAMPER
IN SOME LOCATIONS. ISENTROPIC ASCENT WILL CONTINUE TO STEEPEN AND
EXPAND OVER GEORGIA AND SOUTH CAROLINA TODAY. ANOTHER SHORT WAVE
TROUGH WILL LIFT FROM NORTH GEORGIA THIS MORNING...THROUGH THE
CAROLINAS TODAY WHILE THE AXIS OF THE BAROCLINIC ZONE REMAINS
ENTRENCHED FROM NORTH CENTRAL FLORIDA TO THE GULF STREAM TO OUR
EAST. OUR FORECAST AREA WILL BE IN THE GRIPS OF AN ANCHORED
SURFACE WEDGE PATTERN WHICH WILL REMAIN LOCKED IN UNDER PERIODS OF
LIGHT RAINS AND A NOSE OF WARMING TEMPS AT 925 MB. WE LOWERED
TEMPS TODAY ACROSS THE BOARD GIVEN OVERNIGHT SURFACE ANALYSIS AND
AN EMPHATICALLY COOLER SURFACE TEMP TREND PROGGED BY MANY OF THE
00Z MODELS. SOME AREAS INLAND MAY STRUGGLE TO HIT 50 DEGREES TODAY
TO THE NORTH OF I-16...WHILE RAINS HOLD TEMPS DOWN IN THE LOWER
TO MID 50S IN AREAS SUCH AS DARIEN AND LUDOWICI GEORGIA.

FORECAST SOUNDINGS AND MODEL PROJECTIONS INDICATE MANY AREAS WILL
SEE MEASURABLE LIGHT RAINS TODAY WITH HIGHEST CONFIDENCE ACROSS THE
SE HALF OF THE FORECAST AREA GIVEN THE PROXIMITY TO LOWER CONDENSATION
PRES DEFICITS AND DEEPER MOISTURE FIELDS. POPS AVERAGE OUT IN THE
LIKELY CATEGORY TODAY...BUT RAINFALL AMOUNTS ON THE LIGHT SIDE ONCE
AGAIN.

TONIGHT...RAINFALL COVERAGE WILL EXPAND AS ANOTHER ROUND OF UPPER
SHORT WAVES RIDE NE ALONG THE COOL SIDE OF THE BAROCLINIC ZONE.
MODELS INDICATE A SIGNIFICANT PUNCH OF LOW LEVEL WARM ADVECTION
WILL LIFT THROUGH THE REGION OVERNIGHT AND THIS SHOULD NUDGE THE
COASTAL FRONT WELL OFFSHORE JUST A BIT CLOSER IN...BUT THE WEDGE
WILL REMAIN STRONG AND INTACT ALL AREAS. 1/2 INCH OR LOCALLY
HIGHER RAINFALL AMOUNTS ARE POSSIBLE ALONG COASTAL SE GEORGIA...
OTHERWISE AMOUNTS MAINLY 1/4 INCH OR LESS TONIGHT. WE LOWERED LOW
TEMPS A BIT WITH THE COOL AIR TRAPPED BELOW THE WARM ADVECTION.
THERE IS QUITE A BIT OF CONCERN FOR FOG TONIGHT AS STRATUS COULD
BUILD DOWN AND TANK LOCAL VSBYS. THE AREA OF MOST CONCERN IS
INLAND SE GEORGIA AND LATER FORECASTS MAY NEED SOME STRONGER FOG
MENTIONS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MONDAY...LIGHT SHOWERS SHOULD BE ONGOING TO START THE MORNING AS AN
AREA OF LOW PRESSURE CONTINUES TO LIFT NORTHEAST ALONG THE COAST. A
SOMEWHAT LULL IN PRECIP ACTIVITY IS POSSIBLE DURING THE AFTERNOON
WHILE GREATEST LIFTING SHIFTS TO THE NORTHEAST TEMPORARILY AND A
WEDGE OF HIGH PRESSURE MAINTAINS HOLD INLAND. HOWEVER...GIVEN THE
AMOUNT OF MOISTURE AVAILABLE DURING THE PERIOD...HAVE MAINTAINED
CHANCES OF RAIN THROUGH MONDAY NIGHT. TEMPS WILL BE DEPENDENT ON THE
STRENGTH OF THE WEDGE...BUT SHOULD PEAK INTO THE LOW/MID 50S INLAND
TO UPPER 50S/LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE COAST IN
SOUTH CAROLINA.

MONDAY NIGHT INTO TUESDAY NIGHT...HAVE BACKED OFF CONSIDERABLY ON
POPS TO START OFF MONDAY NIGHT...BUT SHOW AND INCREASING TREND
THROUGH TUESDAY WHILE ANOTHER PLUME OF MOISTURE ADVECTS TO THE AREA
AHEAD OF A COLD FRONT POSITIONED WELL THE OUR WEST. HAVE INTRODUCED
CATEGORICAL POPS TUESDAY AFTERNOON AS A WEAK COASTAL FRONT STRUGGLES
TO LIFT NORTH AGAINST THE PERSISTENT WEDGE INLAND. FOR THIS
REASON...DID NOT EXPAND A SLIGHT CHANCE OF THUNDERSTORMS OVER OUR
INTERIOR COUNTIES. HOWEVER...SBCAPES NEAR 800 J/KG ALONG WITH MODEST
MID LVL LAPSE RATES SHOULD RESULT IN SOME ENHANCEMENT OF SHOWERS AND
PERHAPS A FEW THUNDERSTORMS AS SEVERAL H5 SHORTWAVES SHIFT OVER THE
REGION AHEAD OF THE MAIN TROUGH AXIS DIGGING OVER THE CENTRAL UNITED
STATES. TEMPS WILL ONCE AGAIN BE DEPENDENT ON THE POSITION OF THE
COASTAL FRONT LIFTING NORTH. AT THIS TIME HAVE STAYED SLIGHTLY BELOW
GUIDANCE...WITH OVERALL HIGH TEMPS IN THE LOW 60S INLAND TO MID AND
UPPER 60S SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.

AS DIURNAL HEATING IS LOST TUESDAY NIGHT...THUNDERSTORM CHANCES
SHOULD MAINLY OCCUR OFFSHORE...BUT DEEP MOISTURE CHARACTERIZED BY
PWATS NEAR 1.8 TO 1.9 INCHES SHOULD MAINTAIN WIDESPREAD SHOWERS INTO
WEDNESDAY MORNING WHILE FORCING INCREASES FROM THE WEST. TUESDAY
NIGHT TEMPS WILL BE MILD WITHIN A SOUTH/SOUTHEAST FLOW AHEAD OF THE
APPROACHING COLD FRONT...WITH LOWS ONLY DIPPING INTO THE MID 50S
INLAND TO LOWER 60S ALONG THE COAST.

WEDNESDAY...WIDESPREAD SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS ARE ANTICIPATED AHEAD/ALONG A COLD FRONT THAT IS NOW
EXPECTED TO SHIFT THROUGH THE AREA DURING THE AFTERNOON AND EVENING.
THE DAY SHOULD BRING ABOUT AN INCH OF PRECIP ACCUMULATION OVER MOST
AREAS WITH LOCALLY HIGHER AMOUNTS. STRONG LOW LVL WINDS ALSO SUGGEST
THAT WINDS COULD BE GUSTY WITH SOME MIXING. MODELS INSIST ON WARMING
TEMPS INTO THE LOWER 70S AHEAD OF THE FRONT...BUT WIDESPREAD CLOUD
COVER AND SHOWERS/THUNDERSTORMS SHOULD LIMIT OVERALL HEATING
POTENTIAL. HAVE THEREFORE KEPT HIGH TEMPS A FEW DEGREES BELOW
GUIDANCE...IN THE UPPER 60S TO AROUND 70.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
WIDESPREAD SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL BE POSSIBLE
EARLY WEDNESDAY NIGHT BEFORE A COLD FRONT SHIFTS OFFSHORE. STRONG
COLD AIR ADVECTION BEHIND THE FRONT SHOULD RESULT IN SOME GUSTY WIND
CONDITIONS FOR PART OF THE NIGHT BEFORE ENHANCED WIND FIELDS SLIDE
OFFSHORE. CONDITIONS WILL THEN QUICKLY DRY OUT LATE WEDNESDAY NIGHT
INTO EARLY THURSDAY AS HIGH PRESSURE SETTLES OVER THE REGION BEHIND
THE DEPARTING FRONT AND PERSISTS INTO MUCH OF THE WEEKEND. OVERALL
HIGH TEMPS WILL BE COOLER ON THURSDAY...IN THE MID AND UPPER
50S...BEFORE SLIGHTLY WARMING INTO THE LOWER 60S UNDER A SOMEWHAT
ZONAL FLOW ALOFT. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 30S
THURSDAY NIGHT...BEFORE WARMING INTO THE LOW/MID 40S INTO THE
WEEKEND.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
IFR CIGS SHOULD REMAIN IN PLACE OVERNIGHT WITH SMALL CHANCES OF LIFR
CIGS OR LOW END MVFR CIGS ON EITHER END. A FEW PERIODS OF LIGHT RAIN
AND EVEN SOME DRIZZLE SHOULD CONTINUE. LATEST SOUNDINGS AT KSAV SHOW
IFR CIGS MAY REMAIN LOCKED IN THROUGH THE TAF CYCLE AS RAINFALL
APPEARS LIKELY AND THE WEDGE INVERSION QUITE STRONG. AT KCHS...
MODELS SHOW A DECENT CHANCE THAT CIGS LIFT INTO LOW END MVFR THIS
AFTERNOON BEFORE FALLING TO IFR AGAIN LATE DAY OR EARLY THIS EVENING.
TIMING PERIODS OF LIGHT RAIN AT EITHER TERMINAL IS VERY DIFFICULT
TO PIN DOWN AT THIS TIME.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY NIGHT INTO WEDNESDAY AFTERNOON AS
A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
THUNDERSTORMS. LLWS WILL BE A POSSIBILITY TUESDAY NIGHT AS STRONGER
WIND FIELDS SHIFT OVER THE AREA IN ADVANCE OF THE FRONT. WINDY
CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON
WEDNESDAY. VFR CONDITIONS SHOULD THEN RETURN ON THURSDAY.

&&

.MARINE...
THE NAM AND IT/S LOCAL VARIATION WERE USED TO HANDLE A VERY TRICKY
MARINE FORECAST THIS MORNING AS PINCHING GRADIENT INITIALLY EXTENDING
ALONG THE OUTER FRINGES OF OUR NEAR SHORE SOUTH CAROLINA WATERS
SOUTH INTO THE OUTER GEORGIA WATERS. OVERNIGHT WE RAISED A SMALL
CRAFT ADVISORY FOR GEORGIA WATERS 20-60 NM AS GRAYS REEF HAS BEEN
REPORTING A SOLID 19-20 KT WITH HIGHER GUSTS AND SEAS UP TO 5 FT.

AT SOME POINT TODAY WE MAY NEED TO CONSIDER AN ADVISORY WITHIN 20
NM OF THE COAST BUT IT LOOKS FAIRLY MARGINAL WITH 15-20 KT NE WINDS
AND 4-5 FT COVERING THE SITUATION FOR THE MOST PART. TONIGHT AS
THE COASTAL FRONT TILTS NORTH WHILE A LOW PRES WAVE RIDES THE GULF
STREAM...THE GRADIENT MAY TIGHTEN THIS EVENING ALONG THE CHARLESTON
COAST BUT EVENTUALLY WEAKEN ALL WATERS LATE TONIGHT. MODEL PROGS
SUGGEST IF SMALL CRAFT ADVISORY CONDITIONS HAVE NOT DEVELOPED BY
THIS EVENING....CHANCES ARE DECENT FOR SLIGHTLY DIMINISHED WINDS
AND SEAS AFTER MIDNIGHT. THERE MAY BE SOME LOWER VSBYS AT TIMES
TONIGHT IN RAIN AND FOG OVER THE WATERS.

MONDAY AND TUESDAY...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE PERSISTS INLAND WHILE
LOW PRESSURE SLOWLY LIFTS NORTHEAST ALONG THE COAST. PERIODS OF
RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS THROUGH TUESDAY WHILE A
COASTAL FRONT REMAINS OVER THE COASTAL WATERS. IN GENERAL...WINDS
SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS RANGING BETWEEN
1-3 FT...HIGHEST IN OUTER GEORGIA WATER.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...CONDITIONS SHOULD BEGIN TO
DETERIORATE AS A COASTAL FRONT LIFTS NORTH WELL AHEAD OF A COLD
FRONT THAT EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY EVENING/NIGHT.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF
THE FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY
FLOW. AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY
LEVELS NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS
AHEAD OF THE APPROACHING FRONT. GALE FORCE WIND GUSTS REMAIN POSSIBLE
AS THE COLD FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION
BEHIND IT WEDNESDAY NIGHT. A GALE WATCH/WARNING COULD EVENTUALLY BE
NEEDED FOR A PORTION OF THE WATERS WEDNESDAY NIGHT AS WINDS GUST TO
30-35 KT AWAY FROM THE COAST. SEAS WILL ALSO BUILD UPWARDS TO 5-8
FT WEDNESDAY AFTERNOON INTO EARLY WEDNESDAY NIGHT BEFORE IMPROVING
LATE.

THURSDAY AND FRIDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS
AS HIGH PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS.
WINDS/SEAS SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL
WATERS AROUND DAYBREAK THURSDAY...THEN CONTINUE TO IMPROVE THROUGH
LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES MONDAY...BUT
THE BEST CHANCE OF SEA FOG COULD DEVELOP AS WARMER AIR ARRIVES ATOP
MID/UPPER 50 SHELF WATER TEMPS EARLY TUESDAY PRIOR TO WINDS
INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
THIS MORNING/S HIGH TIDE AROUND 7 AM AT DOWNTOWN CHARLESTON MAY
APPROACH 7 FT MLLW BUT AN ADVISORY IS UNLIKELY AND ANY RAINFALL
AROUND AT THAT TIME WILL BE LIGHT OR JUST SPRINKLES.

GIVEN THE PERIGEAN SPRING TIDES EARLY THIS WEEK...THERE IS AN
INCREASING RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY
AROUND THE TIME OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE
FURTHER EXACERBATED DUE TO STEADY RAINS PRIOR TO AND DURING THE
HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 210619
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
119 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED OVERNIGHT THROUGH TUESDAY AS
SEVERAL DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT
WILL APPROACH LATE TUESDAY NIGHT...THEN SHIFT THROUGH THE AREA ON
WEDNESDAY. DRY HIGH PRESSURE WILL THEN SETTLE OVER THE SOUTHEAST
THROUGH LATE WEEK...WITH A COLD FRONT EXPECTED NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PERIODS OF LIGHT RAIN ARE ANTICIPATED OVERNIGHT. RAINFALL AMOUNTS
CONTINUE TO RUN ON THE LIGHT SIDE.

THE WEDGE REGIME STRATUS COULD PRODUCE SOME DRIZZLE AND COULD
LOWER TOWARD THE SURFACE TO SUPPORT FOG OVERNIGHT. NEAR THE
COAST...PERSISTENT SURFACE WINDS SHOULD LIMIT THE POTENTIAL FOR
SIGNIFICANT DENSE FOG OVERNIGHT...ALTHOUGH CEILINGS COULD
OCCASIONALLY LOWER TO PRODUCE REDUCED VISIBILITY. FARTHER
INLAND...SLIGHTLY HIGHER ELEVATIONS AND LIGHTER WINDS COULD
ENHANCE THE POTENTIAL FOR LOCALLY DENSE FOG.

OTHERWISE...TEMPERATURES WILL FALL ONLY SLOWLY OVERNIGHT AND BY
DAYBREAK WILL RANGE FROM THE LOWER TO MID 40S NORTH TO THE UPPER
40S/LOWER 50S SOUTH AND ON THE COAST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...A WEAK SOUTHERN STREAM MID LEVEL PERTURBATION MOVING
THROUGH THE LOWER MS VALLEY FROM TONIGHT WILL CROSS THE AREA DURING
THE MORNING HOURS AND REINFORCES THE PRE-EXISTING STATIONARY FRONT
OVER THE ATLANTIC TO THE EAST/SE OF THE GULF STREAM. IT ALSO KEEPS
THE INLAND COOL HIGH PRESSURE WEDGE ANCHORED IN PLACE AS IT EXTENDS
SOUTH OF THE FORECAST AREA. THE IMPULSE ALOFT ALSO TRIGGERS WEAK
CYCLOGENESIS OFF THE SE COAST SOME 250 NM EAST OF SAVANNAH AS IT
MOVES LITTLE THROUGHOUT THE DAY. ISENTROPIC ASCENT WILL AGAIN BE THE
MAIN FACTOR FOR GENERATING RAINFALL...AS IT INCREASES IN MAGNITUDE
DURING THE AFTERNOON AND EVENING HOURS...AND POPS ACCORDINGLY WILL
BE ON THE INCREASE AS WELL DURING THE SECOND HALF OF THE DAY. WE/LL
START THE PERIOD WITH A LITTLE LIGHT RAIN...DRIZZLE AND/OR FOG
BEFORE POPS CLIMB INTO THE 30-50 PERCENTILE IN THE AFTERNOON.
GREATEST PROBABILITIES WILL BE OVER SE GA AND ESPECIALLY SOUTH OF
I-16 DURING THAT TIME. OVERCAST SKIES AND A CONTINUED FEED OF AIR
FROM THE NORTH/NE WITHIN THE LOW LEVEL WEDGE WILL KEEP TEMPS DOWN
MAINLY INTO THE 50S FOR MAX TEMPS.

SUNDAY NIGHT INTO MONDAY...ANOTHER AND SLIGHTLY STRONGER SHORT WAVE
ARRIVES FROM THE GULF OF MEXICO AND FORCES THE ATLANTIC WAVE TO
DEEPEN A FEW MILLIBARS AS IT LIFTS NE ROUGHLY ALONG THE GULF STREAM
TO A POSITION OFF CAPE HATTERAS BY 00Z TUESDAY. THIS PATTERN
REINFORCES THE WEDGE INLAND...WHICH IN TURN ALLOWS FOR A FURTHER
INCREASE IN ISENTROPIC ASCENT. THAT ALONG WITH FORCING FROM THE
UPPER JET OVER THE SE CORNER OF THE COUNTRY AND CONVERGENCE
ASSOCIATED WITH THE NEARBY ATLANTIC LOW WILL CAUSE COVERAGE OF RAIN
TO EXPAND INTO AT LEAST THE 70-80 PERCENT RANGE SUNDAY
NIGHT...BEFORE COVERAGE DIMINISHES FROM WEST TO EAST ON MONDAY AS THE
SURFACE LOW PULLS AWAY. PWATS OF 1.3 TO 1.4 INCHES AND THE FLOW
ALOFT OPENING MORE OUT OF THE GULF OF MEXICO SUPPORTS AT LEAST 1/4
TO 1/2 INCH AMOUNTS OF RAIN. IN ADDITION...STEEPER MID LEVEL LAPSE
RATES AND SHOWALTER INDICES DROPPING TO NEAR ZERO COULD SUPPORT A
LITTLE ELEVATED CONVECTION. LOW STRATUS DECKS WILL ALSO SUPPORT SOME
REDUCTION IN SURFACE VISIBILITIES SUNDAY NIGHT INTO MONDAY MORNING
AND WE HAVE ADDED PATCHY FOG TO THE FORECAST. THERE IS ONLY A SMALL
5-10 DEGREE TEMP SWING FROM DAYTIME HIGHS SUNDAY TO NIGHTTIME LOWS
SUNDAY NIGHT. THEN A FAIRLY LARGE NORTH/NW TO SOUTH/SE TEMP GRADIENT
MONDAY WITH HIGHS NEAR OR SLIGHTLY BELOW NORMAL.

MONDAY NIGHT AND TUESDAY...YET ANOTHER QUICK MOVING SOUTHERN STREAM
SHORT WAVE ARRIVES LATE MONDAY NIGHT AND TUESDAY FROM THE GULF OF
MEXICO. FURTHER UPSTREAM A MORE PRONOUNCED SHORT WAVE STARTS TO DIG
THROUGH THE CENTRAL STATES...WHICH IN TURN AMPLIFIES THE LARGE SCALE
PATTERN ACROSS THE CONUS. THIS BACKS OUR FLOW ALOFT FURTHER TO THE
SW AND OPENS THE DOOR FOR A FEED OF EVEN DEEPER AND TROPICAL-LIKE
MOISTURE TO MOVE IN. PWATS CLIMB TO NEAR 2 STANDARD DEVIATIONS ABOVE
NORMAL...AROUND 1.6 TO 1.7 INCHES SO YET ANOTHER ROUND OF RAINFALL
WILL OCCUR. POPS WILL BE IN THE CHANCE TO LIKELY RANGE MONDAY NIGHT
THEN SHOULD PEAK IN THE CATEGORICAL RANGE TUESDAY. ADDITIONAL QPF
WILL BE AT LEAST 1/2 TO 3/4 INCHES...WITH POTENTIAL HIGHER AMOUNTS
IN THIS PATTERN. THE SHORT WAVE IN THE PLAINS WILL ALSO TRIGGER
CYCLOGENESIS NEAR THE ARKLATEX REGION BY TUESDAY...WHICH IN TURN
ATTEMPTS TO LIFT OUR COASTAL WARM FRONT NORTHWARD. NOT SURE HOW THIS
PROGRESSION WILL ACTUAL PAN OUT GIVEN THAT THE INLAND WEDGE WILL BE
RELUCTANT TO GIVE UP ITS HOLD. THIS WILL ALLOW FOR WARM ADVECTION TO
BOOST TEMPS AT LEAST INTO THE LOWER OR MIDDLE 60S...PERHAPS EVEN
HIGHER NEAR THE ALTAMAHA. THIS IN TURN CREATES SOME SURFACE BASED
INSTABILITY ON THE ORDER OF 500-800 J/KG IN SYNC WITH STEEP MID
LEVEL LAPSE RATES OVER OUR COASTAL ZONES AND SOUTH OF I-16. IT/S IN
THESE AREAS WHERE WE HAVE ISOLATED T-STORMS MENTIONED IN THE LATEST
FORECAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
IFR CIGS SHOULD REMAIN IN PLACE OVERNIGHT WITH SMALL CHANCES OF LIFR
CIGS OR LOW END MVFR CIGS ON EITHER END. A FEW PERIODS OF LIGHT RAIN
AND EVEN SOME DRIZZLE SHOULD CONTINUE. LATEST SOUNDINGS AT KSAV SHOW
IFR CIGS MAY REMAIN LOCKED IN THROUGH THE TAF CYCLE AS RAINFALL
APPEARS LIKELY AND THE WEDGE INVERSION QUITE STRONG. AT KCHS...
MODELS SHOW A DECENT CHANCE THAT CIGS LIFT INTO LOW END MVFR THIS
AFTERNOON BEFORE FALLING TO IFR AGAIN LATE DAY OR EARLY THIS EVENING.
TIMING PERIODS OF LIGHT RAIN AT EITHER TERMINAL IS VERY DIFFICULT
TO PIN DOWN AT THIS TIME.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH EARLY TUESDAY
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON AS A STRONG COLD FRONT APPROACHES FROM THE
WEST WITH SHOWERS AND POSSIBLY THUNDERSTORMS. WINDY CONDITIONS
SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
OVERNIGHT...BASED ON THE LATEST SURFACE ANALYSIS AND NEAR TERM PROGS
AS WELL AS THE OBSERVATION FROM GRAYS REEF...WE HOISTED A SMALL CRAFT
ADVISORY FOR THE GEORGIA WATERS 20-60 NM OFFSHORE. WINDS ALL WATERS
15-20 KT OVERNIGHT WITH HIGHER GUSTS 20 NM AND BEYOND WITH SEAS
3-5 FT NEAR SHORE AND 4-6 FT OFFSHORE.

SUNDAY...A PINCHED PRESSURE GRADIENT BETWEEN DEVELOPING LOW PRESSURE
OFF THE GA COAST NEAR THE GULF STREAM AND A STRONG INLAND WEDGE OF
HIGH PRESSURE WILL PERSIST. THIS WILL RESULT IN NORTH/NE WINDS OF AT
LEAST 15-20 KT...WITH GUSTS AT TIMES TO NEAR 25 KT. THE SCA WILL
CONTINUE FOR THE GEORGIA OUTER WATERS AND MAY BE NEED OVER PARTS OF
THE NEAR SHORE WATERS.

SUNDAY NIGHT AND MONDAY...THE ATLANTIC WAVE DEEPENS SOME AS IT
LIFTS NE ALONG THE GULF STREAM...WHILE THE INLAND WEDGE HOLDS
FIRM. THE GRADIENT THOUGH DOES SLACKEN SOME OF THE LOW SHIFTS
NORTH OF THE LOCAL WATERS...AND WINDS AND SEAS WILL BE LESS AND
BELOW ANY ADVISORY CRITERIA.

MONDAY NIGHT AND TUESDAY...THE INLAND WEDGE IS STILL IN PLACE DURING
MUCH OF THE PERIOD...BUT IT DOES ATTEMPT TO ERODE BY TUESDAY NIGHT
AS THE COASTAL WARM FRONT STARTS TO LIFT NORTH/NW. UNTIL THIS
TRANSITION THOUGH OUR WINDS WILL STRUGGLE TO VEER AROUND...AS SPEEDS
HOLD NEAR OR BELOW 15 KT AND SEAS ARE LIMITED TO 3 OR 4 FT.

TUESDAY NIGHT AND WEDNESDAY...FINALLY THE COASTAL WARM FRONT WILL
SHIFT NORTH OF THE LOCAL WATERS TUESDAY NIGHT AS A STRONG COLD FRONT
MOVES THROUGH WEDNESDAY. WARM ADVECTION AND THE RESULTING
MARINE-LAYERING EFFECTS WILL LIMIT THE STRENGTH OF WINDS AHEAD OF
THE FRONT...BUT SMALL CRAFT ADVISORIES ARE CERTAINLY POSSIBLE.
BEHIND THE FRONT THE COMBINATION OF COLD ADVECTION AND STRONG
ISALLOBARIC PRESSURE RISES MAY SUPPORT GALES...OR AT THE LEAST SMALL
CRAFT ADVISORIES. MARINERS ARE ALSO ADVISED THAT SOME STRONGER
T-STORMS ARE POSSIBLE IN ADVANCE OF THE COLD FRONT...CAPABLE OF
PRODUCING GUSTY WINDS AND LIGHTNING STRIKES.

THURSDAY...CONDITIONS WILL IMPROVE OVER ALL WATERS AS HIGH PRESSURE
BECOMES CENTERED JUST SOUTH OF THE AREA. WINDS/SEAS SHOULD
EVENTUALLY LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL MARINE
ZONES AS COLD ADVECTION WANES AND THE GRADIENT RELAXES.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
INTO TUESDAY. ACTUAL SEA FOG MAY HAVE A WINDOW TO DEVELOP AS
SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE TUESDAY INTO TUESDAY NIGHT
PRIOR TO WINDS INCREASING ENOUGH TO SCOUR IT OUT SOMETIME ON
WEDNESDAY.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...GIVEN
THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AN INCREASING
RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY AROUND THE TIME
OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE FURTHER EXACERBATED
DUE TO STEADY RAINS PRIOR TO AND DURING THE HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...33
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 210619
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
119 AM EST SUN DEC 21 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED OVERNIGHT THROUGH TUESDAY AS
SEVERAL DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT
WILL APPROACH LATE TUESDAY NIGHT...THEN SHIFT THROUGH THE AREA ON
WEDNESDAY. DRY HIGH PRESSURE WILL THEN SETTLE OVER THE SOUTHEAST
THROUGH LATE WEEK...WITH A COLD FRONT EXPECTED NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PERIODS OF LIGHT RAIN ARE ANTICIPATED OVERNIGHT. RAINFALL AMOUNTS
CONTINUE TO RUN ON THE LIGHT SIDE.

THE WEDGE REGIME STRATUS COULD PRODUCE SOME DRIZZLE AND COULD
LOWER TOWARD THE SURFACE TO SUPPORT FOG OVERNIGHT. NEAR THE
COAST...PERSISTENT SURFACE WINDS SHOULD LIMIT THE POTENTIAL FOR
SIGNIFICANT DENSE FOG OVERNIGHT...ALTHOUGH CEILINGS COULD
OCCASIONALLY LOWER TO PRODUCE REDUCED VISIBILITY. FARTHER
INLAND...SLIGHTLY HIGHER ELEVATIONS AND LIGHTER WINDS COULD
ENHANCE THE POTENTIAL FOR LOCALLY DENSE FOG.

OTHERWISE...TEMPERATURES WILL FALL ONLY SLOWLY OVERNIGHT AND BY
DAYBREAK WILL RANGE FROM THE LOWER TO MID 40S NORTH TO THE UPPER
40S/LOWER 50S SOUTH AND ON THE COAST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...A WEAK SOUTHERN STREAM MID LEVEL PERTURBATION MOVING
THROUGH THE LOWER MS VALLEY FROM TONIGHT WILL CROSS THE AREA DURING
THE MORNING HOURS AND REINFORCES THE PRE-EXISTING STATIONARY FRONT
OVER THE ATLANTIC TO THE EAST/SE OF THE GULF STREAM. IT ALSO KEEPS
THE INLAND COOL HIGH PRESSURE WEDGE ANCHORED IN PLACE AS IT EXTENDS
SOUTH OF THE FORECAST AREA. THE IMPULSE ALOFT ALSO TRIGGERS WEAK
CYCLOGENESIS OFF THE SE COAST SOME 250 NM EAST OF SAVANNAH AS IT
MOVES LITTLE THROUGHOUT THE DAY. ISENTROPIC ASCENT WILL AGAIN BE THE
MAIN FACTOR FOR GENERATING RAINFALL...AS IT INCREASES IN MAGNITUDE
DURING THE AFTERNOON AND EVENING HOURS...AND POPS ACCORDINGLY WILL
BE ON THE INCREASE AS WELL DURING THE SECOND HALF OF THE DAY. WE/LL
START THE PERIOD WITH A LITTLE LIGHT RAIN...DRIZZLE AND/OR FOG
BEFORE POPS CLIMB INTO THE 30-50 PERCENTILE IN THE AFTERNOON.
GREATEST PROBABILITIES WILL BE OVER SE GA AND ESPECIALLY SOUTH OF
I-16 DURING THAT TIME. OVERCAST SKIES AND A CONTINUED FEED OF AIR
FROM THE NORTH/NE WITHIN THE LOW LEVEL WEDGE WILL KEEP TEMPS DOWN
MAINLY INTO THE 50S FOR MAX TEMPS.

SUNDAY NIGHT INTO MONDAY...ANOTHER AND SLIGHTLY STRONGER SHORT WAVE
ARRIVES FROM THE GULF OF MEXICO AND FORCES THE ATLANTIC WAVE TO
DEEPEN A FEW MILLIBARS AS IT LIFTS NE ROUGHLY ALONG THE GULF STREAM
TO A POSITION OFF CAPE HATTERAS BY 00Z TUESDAY. THIS PATTERN
REINFORCES THE WEDGE INLAND...WHICH IN TURN ALLOWS FOR A FURTHER
INCREASE IN ISENTROPIC ASCENT. THAT ALONG WITH FORCING FROM THE
UPPER JET OVER THE SE CORNER OF THE COUNTRY AND CONVERGENCE
ASSOCIATED WITH THE NEARBY ATLANTIC LOW WILL CAUSE COVERAGE OF RAIN
TO EXPAND INTO AT LEAST THE 70-80 PERCENT RANGE SUNDAY
NIGHT...BEFORE COVERAGE DIMINISHES FROM WEST TO EAST ON MONDAY AS THE
SURFACE LOW PULLS AWAY. PWATS OF 1.3 TO 1.4 INCHES AND THE FLOW
ALOFT OPENING MORE OUT OF THE GULF OF MEXICO SUPPORTS AT LEAST 1/4
TO 1/2 INCH AMOUNTS OF RAIN. IN ADDITION...STEEPER MID LEVEL LAPSE
RATES AND SHOWALTER INDICES DROPPING TO NEAR ZERO COULD SUPPORT A
LITTLE ELEVATED CONVECTION. LOW STRATUS DECKS WILL ALSO SUPPORT SOME
REDUCTION IN SURFACE VISIBILITIES SUNDAY NIGHT INTO MONDAY MORNING
AND WE HAVE ADDED PATCHY FOG TO THE FORECAST. THERE IS ONLY A SMALL
5-10 DEGREE TEMP SWING FROM DAYTIME HIGHS SUNDAY TO NIGHTTIME LOWS
SUNDAY NIGHT. THEN A FAIRLY LARGE NORTH/NW TO SOUTH/SE TEMP GRADIENT
MONDAY WITH HIGHS NEAR OR SLIGHTLY BELOW NORMAL.

MONDAY NIGHT AND TUESDAY...YET ANOTHER QUICK MOVING SOUTHERN STREAM
SHORT WAVE ARRIVES LATE MONDAY NIGHT AND TUESDAY FROM THE GULF OF
MEXICO. FURTHER UPSTREAM A MORE PRONOUNCED SHORT WAVE STARTS TO DIG
THROUGH THE CENTRAL STATES...WHICH IN TURN AMPLIFIES THE LARGE SCALE
PATTERN ACROSS THE CONUS. THIS BACKS OUR FLOW ALOFT FURTHER TO THE
SW AND OPENS THE DOOR FOR A FEED OF EVEN DEEPER AND TROPICAL-LIKE
MOISTURE TO MOVE IN. PWATS CLIMB TO NEAR 2 STANDARD DEVIATIONS ABOVE
NORMAL...AROUND 1.6 TO 1.7 INCHES SO YET ANOTHER ROUND OF RAINFALL
WILL OCCUR. POPS WILL BE IN THE CHANCE TO LIKELY RANGE MONDAY NIGHT
THEN SHOULD PEAK IN THE CATEGORICAL RANGE TUESDAY. ADDITIONAL QPF
WILL BE AT LEAST 1/2 TO 3/4 INCHES...WITH POTENTIAL HIGHER AMOUNTS
IN THIS PATTERN. THE SHORT WAVE IN THE PLAINS WILL ALSO TRIGGER
CYCLOGENESIS NEAR THE ARKLATEX REGION BY TUESDAY...WHICH IN TURN
ATTEMPTS TO LIFT OUR COASTAL WARM FRONT NORTHWARD. NOT SURE HOW THIS
PROGRESSION WILL ACTUAL PAN OUT GIVEN THAT THE INLAND WEDGE WILL BE
RELUCTANT TO GIVE UP ITS HOLD. THIS WILL ALLOW FOR WARM ADVECTION TO
BOOST TEMPS AT LEAST INTO THE LOWER OR MIDDLE 60S...PERHAPS EVEN
HIGHER NEAR THE ALTAMAHA. THIS IN TURN CREATES SOME SURFACE BASED
INSTABILITY ON THE ORDER OF 500-800 J/KG IN SYNC WITH STEEP MID
LEVEL LAPSE RATES OVER OUR COASTAL ZONES AND SOUTH OF I-16. IT/S IN
THESE AREAS WHERE WE HAVE ISOLATED T-STORMS MENTIONED IN THE LATEST
FORECAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
IFR CIGS SHOULD REMAIN IN PLACE OVERNIGHT WITH SMALL CHANCES OF LIFR
CIGS OR LOW END MVFR CIGS ON EITHER END. A FEW PERIODS OF LIGHT RAIN
AND EVEN SOME DRIZZLE SHOULD CONTINUE. LATEST SOUNDINGS AT KSAV SHOW
IFR CIGS MAY REMAIN LOCKED IN THROUGH THE TAF CYCLE AS RAINFALL
APPEARS LIKELY AND THE WEDGE INVERSION QUITE STRONG. AT KCHS...
MODELS SHOW A DECENT CHANCE THAT CIGS LIFT INTO LOW END MVFR THIS
AFTERNOON BEFORE FALLING TO IFR AGAIN LATE DAY OR EARLY THIS EVENING.
TIMING PERIODS OF LIGHT RAIN AT EITHER TERMINAL IS VERY DIFFICULT
TO PIN DOWN AT THIS TIME.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH EARLY TUESDAY
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON AS A STRONG COLD FRONT APPROACHES FROM THE
WEST WITH SHOWERS AND POSSIBLY THUNDERSTORMS. WINDY CONDITIONS
SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
OVERNIGHT...BASED ON THE LATEST SURFACE ANALYSIS AND NEAR TERM PROGS
AS WELL AS THE OBSERVATION FROM GRAYS REEF...WE HOISTED A SMALL CRAFT
ADVISORY FOR THE GEORGIA WATERS 20-60 NM OFFSHORE. WINDS ALL WATERS
15-20 KT OVERNIGHT WITH HIGHER GUSTS 20 NM AND BEYOND WITH SEAS
3-5 FT NEAR SHORE AND 4-6 FT OFFSHORE.

SUNDAY...A PINCHED PRESSURE GRADIENT BETWEEN DEVELOPING LOW PRESSURE
OFF THE GA COAST NEAR THE GULF STREAM AND A STRONG INLAND WEDGE OF
HIGH PRESSURE WILL PERSIST. THIS WILL RESULT IN NORTH/NE WINDS OF AT
LEAST 15-20 KT...WITH GUSTS AT TIMES TO NEAR 25 KT. THE SCA WILL
CONTINUE FOR THE GEORGIA OUTER WATERS AND MAY BE NEED OVER PARTS OF
THE NEAR SHORE WATERS.

SUNDAY NIGHT AND MONDAY...THE ATLANTIC WAVE DEEPENS SOME AS IT
LIFTS NE ALONG THE GULF STREAM...WHILE THE INLAND WEDGE HOLDS
FIRM. THE GRADIENT THOUGH DOES SLACKEN SOME OF THE LOW SHIFTS
NORTH OF THE LOCAL WATERS...AND WINDS AND SEAS WILL BE LESS AND
BELOW ANY ADVISORY CRITERIA.

MONDAY NIGHT AND TUESDAY...THE INLAND WEDGE IS STILL IN PLACE DURING
MUCH OF THE PERIOD...BUT IT DOES ATTEMPT TO ERODE BY TUESDAY NIGHT
AS THE COASTAL WARM FRONT STARTS TO LIFT NORTH/NW. UNTIL THIS
TRANSITION THOUGH OUR WINDS WILL STRUGGLE TO VEER AROUND...AS SPEEDS
HOLD NEAR OR BELOW 15 KT AND SEAS ARE LIMITED TO 3 OR 4 FT.

TUESDAY NIGHT AND WEDNESDAY...FINALLY THE COASTAL WARM FRONT WILL
SHIFT NORTH OF THE LOCAL WATERS TUESDAY NIGHT AS A STRONG COLD FRONT
MOVES THROUGH WEDNESDAY. WARM ADVECTION AND THE RESULTING
MARINE-LAYERING EFFECTS WILL LIMIT THE STRENGTH OF WINDS AHEAD OF
THE FRONT...BUT SMALL CRAFT ADVISORIES ARE CERTAINLY POSSIBLE.
BEHIND THE FRONT THE COMBINATION OF COLD ADVECTION AND STRONG
ISALLOBARIC PRESSURE RISES MAY SUPPORT GALES...OR AT THE LEAST SMALL
CRAFT ADVISORIES. MARINERS ARE ALSO ADVISED THAT SOME STRONGER
T-STORMS ARE POSSIBLE IN ADVANCE OF THE COLD FRONT...CAPABLE OF
PRODUCING GUSTY WINDS AND LIGHTNING STRIKES.

THURSDAY...CONDITIONS WILL IMPROVE OVER ALL WATERS AS HIGH PRESSURE
BECOMES CENTERED JUST SOUTH OF THE AREA. WINDS/SEAS SHOULD
EVENTUALLY LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL MARINE
ZONES AS COLD ADVECTION WANES AND THE GRADIENT RELAXES.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
INTO TUESDAY. ACTUAL SEA FOG MAY HAVE A WINDOW TO DEVELOP AS
SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE TUESDAY INTO TUESDAY NIGHT
PRIOR TO WINDS INCREASING ENOUGH TO SCOUR IT OUT SOMETIME ON
WEDNESDAY.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...GIVEN
THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AN INCREASING
RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY AROUND THE TIME
OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE FURTHER EXACERBATED
DUE TO STEADY RAINS PRIOR TO AND DURING THE HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...33
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 210312
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1012 PM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED OVERNIGHT THROUGH TUESDAY AS
SEVERAL DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT
WILL APPROACH LATE TUESDAY NIGHT...THEN SHIFT THROUGH THE AREA ON
WEDNESDAY. DRY HIGH PRESSURE WILL THEN SETTLE OVER THE SOUTHEAST
THROUGH LATE WEEK...WITH A COLD FRONT EXPECTED NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LATE SATURDAY EVENING...SATELLITE IMAGERY AND AREA RADAR TRENDS
CONTINUED TO DEPICT A WEAK SHORTWAVE TROUGH ALOFT AND ASSOCIATED
AREAS OF LIGHT RAIN EJECTING ENE TOWARD THE AREA. INITIALLY...
POPS GRADUATED FROM HIGH CHANCE ALONG/SOUTH OF INTERSTATE 16 TO
BELOW 15 PERCENT ACROSS FAR NORTHERN COUNTIES WILL SUFFICE AS
MID/UPPER LEVEL DRY AIR HAS TEMPORARILY OVERSPREAD THE REGION AS
SHOWN BY THE 00Z KCHS SOUNDING AND WATER VAPOR IMAGERY. ALSO...
RECENT SURFACE OBSERVATIONS SUGGEST THAT PRECIPITATION THUS FAR
HAS REMAINED LIGHT. HOWEVER...AS THE NIGHT PROGRESSES...MODEL
CONSENSUS INCLUDING RECENT HIGH RESOLUTION SOLUTIONS SUGGEST THAT
PRECIPITATION COVERAGE WILL INCREASE. ACCORDINGLY...RAMPED UP POPS
OVERNIGHT...EVENTUALLY TAPERED FROM LIKELY/HIGH CHANCE ACROSS
SOUTHERN AND COASTAL COUNTIES TO CHANCE INLAND. GIVEN THE MOST
RECENT RUC13 AND HRRR GUIDANCE...LIGHT RAIN YET BECOME MORE
WIDESPREAD THAN INDICATED WITHIN THE LATE EVENING UPDATE...AND
HIGHER POPS COULD BE REQUIRED WITHIN SUBSEQUENT FORECASTS.

MEANWHILE...WITHIN THE WEDGE REGIME STRATUS COULD PRODUCE SOME
DRIZZLE AND COULD LOWER TOWARD THE SURFACE TO SUPPORT FOG
OVERNIGHT. NEAR THE COAST...PERSISTENT SURFACE WINDS SHOULD
LIMIT THE POTENTIAL FOR SIGNIFICANT DENSE FOG OVERNIGHT...ALTHOUGH
CEILINGS COULD OCCASIONALLY LOWER TO PRODUCE REDUCED VISIBILITY.
FARTHER INLAND...SLIGHTLY HIGHER ELEVATIONS AND LIGHTER WINDS
COULD ENHANCE THE POTENTIAL FOR LOCALLY DENSE FOG.

OTHERWISE...TEMPERATURES WILL FALL ONLY SLOWLY OVERNIGHT AND BY
DAYBREAK WILL RANGE FROM THE LOWER TO MID 40S NORTH TO THE UPPER
40S/LOWER 50S SOUTH AND ON THE COAST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...A WEAK SOUTHERN STREAM MID LEVEL PERTURBATION MOVING
THROUGH THE LOWER MS VALLEY FROM TONIGHT WILL CROSS THE AREA DURING
THE MORNING HOURS AND REINFORCES THE PRE-EXISTING STATIONARY FRONT
OVER THE ATLANTIC TO THE EAST/SE OF THE GULF STREAM. IT ALSO KEEPS
THE INLAND COOL HIGH PRESSURE WEDGE ANCHORED IN PLACE AS IT EXTENDS
SOUTH OF THE FORECAST AREA. THE IMPULSE ALOFT ALSO TRIGGERS WEAK
CYCLOGENESIS OFF THE SE COAST SOME 250 NM EAST OF SAVANNAH AS IT
MOVES LITTLE THROUGHOUT THE DAY. ISENTROPIC ASCENT WILL AGAIN BE THE
MAIN FACTOR FOR GENERATING RAINFALL...AS IT INCREASES IN MAGNITUDE
DURING THE AFTERNOON AND EVENING HOURS...AND POPS ACCORDINGLY WILL
BE ON THE INCREASE AS WELL DURING THE SECOND HALF OF THE DAY. WE/LL
START THE PERIOD WITH A LITTLE LIGHT RAIN...DRIZZLE AND/OR FOG
BEFORE POPS CLIMB INTO THE 30-50 PERCENTILE IN THE AFTERNOON.
GREATEST PROBABILITIES WILL BE OVER SE GA AND ESPECIALLY SOUTH OF
I-16 DURING THAT TIME. OVERCAST SKIES AND A CONTINUED FEED OF AIR
FROM THE NORTH/NE WITHIN THE LOW LEVEL WEDGE WILL KEEP TEMPS DOWN
MAINLY INTO THE 50S FOR MAX TEMPS.

SUNDAY NIGHT INTO MONDAY...ANOTHER AND SLIGHTLY STRONGER SHORT WAVE
ARRIVES FROM THE GULF OF MEXICO AND FORCES THE ATLANTIC WAVE TO
DEEPEN A FEW MILLIBARS AS IT LIFTS NE ROUGHLY ALONG THE GULF STREAM
TO A POSITION OFF CAPE HATTERAS BY 00Z TUESDAY. THIS PATTERN
REINFORCES THE WEDGE INLAND...WHICH IN TURN ALLOWS FOR A FURTHER
INCREASE IN ISENTROPIC ASCENT. THAT ALONG WITH FORCING FROM THE
UPPER JET OVER THE SE CORNER OF THE COUNTRY AND CONVERGENCE
ASSOCIATED WITH THE NEARBY ATLANTIC LOW WILL CAUSE COVERAGE OF RAIN
TO EXPAND INTO AT LEAST THE 70-80 PERCENT RANGE SUNDAY
NIGHT...BEFORE COVERAGE DIMINISHES FROM WEST TO EST ON MONDAY AS THE
SURFACE LOW PULLS AWAY. PWATS OF 1.3 TO 1.4 INCHES AND THE FLOW
ALOFT OPENING MORE OUT OF THE GULF OF MEXICO SUPPORTS AT LEAST 1/4
TO 1/2 INCH AMOUNTS OF RAIN. IN ADDITION...STEEPER MID LEVEL LAPSE
RATES AND SHOWALTER INDICES DROPPING TO NEAR ZERO COULD SUPPORT A
LITTLE ELEVATED CONVECTION. LOW STRATUS DECKS WILL ALSO SUPPORT SOME
REDUCTION IN SURFACE VISIBILITIES SUNDAY NIGHT INTO MONDAY MORNING
AND WE HAVE ADDED PATCHY FOG TO THE FORECAST. THERE IS ONLY A SMALL
5-10 DEGREE TEMP SWING FROM DAYTIME HIGHS SUNDAY TO NIGHTTIME LOWS
SUNDAY NIGHT. THEN A FAIRLY LARGE NORTH/NW TO SOUTH/SE TEMP GRADIENT
MONDAY WITH HIGHS NEAR OR SLIGHTLY BELOW NORMAL.

MONDAY NIGHT AND TUESDAY...YET ANOTHER QUICK MOVING SOUTHERN STREAM
SHORT WAVE ARRIVES LATE MONDAY NIGHT AND TUESDAY FROM THE GULF OF
MEXICO. FURTHER UPSTREAM A MORE PRONOUNCED SHORT WAVE STARTS TO DIG
THROUGH THE CENTRAL STATES...WHICH IN TURN AMPLIFIES THE LARGE SCALE
PATTERN ACROSS THE CONUS. THIS BACKS OUR FLOW ALOFT FURTHER TO THE
SW AND OPENS THE DOOR FOR A FEED OF EVEN DEEPER AND TROPICAL-LIKE
MOISTURE TO MOVE IN. PWATS CLIMB TO NEAR 2 STANDARD DEVIATIONS ABOVE
NORMAL...AROUND 1.6 TO 1.7 INCHES SO YET ANOTHER ROUND OF RAINFALL
WILL OCCUR. POPS WILL BE IN THE CHANCE TO LIKELY RANGE MONDAY NIGHT
THEN SHOULD PEAK IN THE CATEGORICAL RANGE TUESDAY. ADDITIONAL QPF
WILL BE AT LEAST 1/2 TO 3/4 INCHES...WITH POTENTIAL HIGHER AMOUNTS
IN THIS PATTERN. THE SHORT WAVE IN THE PLAINS WILL ALSO TRIGGER
CYCLOGENESIS NEAR THE ARKLATEX REGION BY TUESDAY...WHICH IN TURN
ATTEMPTS TO LIFT OUR COASTAL WARM FRONT NORTHWARD. NOT SURE HOW THIS
PROGRESSION WILL ACTUAL PAN OUT GIVEN THAT THE INLAND WEDGE WILL BE
RELUCTANT TO GIVE UP ITS HOLD. THIS WILL ALLOW FOR WARM ADVECTION TO
BOOST TEMPS AT LEAST INTO THE LOWER OR MIDDLE 60S...PERHAPS EVEN
HIGHER NEAR THE ALTAMAHA. THIS IN TURN CREATES SOME SURFACE BASED
INSTABILITY ON THE ORDER OF 500-800 J/KG IN SYNC WITH STEEP MID
LEVEL LAPSE RATES OVER OUR COASTAL ZONES AND SOUTH OF I-16. IT/S IN
THESE AREAS WHERE WE HAVE ISOLATED T-STORMS MENTIONED IN THE LATEST
FORECAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
DO NOT EXPECTED IMPROVEMENT BEYOND MVFR CEILINGS TONIGHT AND
SUNDAY...AND IFR/LIFR CEILINGS WILL PREVAIL MUCH OF THE TIME THIS
EVENING INTO SUNDAY MORNING. PREVALENCE OF LIGHT RAIN REMAINS
SOMEWHAT UNCERTAIN AS ADDITIONAL WAVES PUSH E/NE INTO THE REGION
OVERNIGHT AND AGAIN SUNDAY. HIGHEST POPS SHOULD OCCUR AT KSAV
TONIGHT...ALTHOUGH RAIN COULD EXPAND INTO THE KCHS AREA. EVEN IF A
BREAK IN PRECIPITATION DEVELOPS LATE TONIGHT INTO SUNDAY MORNING...
ANOTHER ROUND OF RAIN SHOULD COMMENCE AT BOTH SITES SUNDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH EARLY TUESDAY
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON AS A STRONG COLD FRONT APPROACHES FROM THE
WEST WITH SHOWERS AND POSSIBLY THUNDERSTORMS. WINDY CONDITIONS
SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
OVERNIGHT...MARINE LAYER MIXING AND A TIGHT SURFACE PRESSURE
GRADIENT BETWEEN AN INLAND WEDGE OF HIGH PRESSURE AND A TROUGH OF
LOW PRESSURE OVER THE GULF STREAM WILL MAINTAIN ELEVATED NORTHEAST
WINDS...AS HIGH AS 15-20 KT...AND ASSOCIATED SEAS 3-5 FT...HIGHEST
BEYOND 20 NM. OVERALL...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY LEVELS.

SUNDAY...A PINCHED PRESSURE GRADIENT BETWEEN DEVELOPING LOW PRESSURE
OFF THE GA COAST NEAR THE GULF STREAM AND A STRONG INLAND WEDGE OF
HIGH PRESSURE WILL PERSIST. THIS WILL RESULT IN NORTH/NE WINDS OF AT
LEAST 15-20 KT...WITH GUSTS AT TIMES TO NEAR 25 KT. IF THE GUSTS
BECOME FREQUENT ENOUGH WE/D NEED A SMALL CRAFT ADVISORY...WHICH
WE/LL DEFER TO FUTURE SHIFTS TO SEE IF WE INDEED SHOULD HOIST THE
ADVISORY HEADLINE. THE FETCH IS FAVORABLE ENOUGH FOR SEAS TO BE AS
HIGH AS 3-5 FT...GREATEST OVER AMZ374 AND THE EASTERNMOST PARTS OF
AMZ350.

SUNDAY NIGHT AND MONDAY...THE ATLANTIC WAVE DEEPENS SOME AS IT LIFTS
NE ALONG THE GULF STREAM...WHILE THE INLAND WEDGE HOLDS FIRM. THE
GRADIENT THOUGH DOES SLACKEN SOME OF THE LOW SHIFTS NORTH OF THE
LOCAL WATERS...AND WINDS AND SEAS WILL BE LESS AND BELOW ANY
ADVISORY CRITERIA.

MONDAY NIGHT AND TUESDAY...THE INLAND WEDGE IS STILL IN PLACE DURING
MUCH OF THE PERIOD...BUT IT DOES ATTEMPT TO ERODE BY TUESDAY NIGHT
AS THE COASTAL WARM FRONT STARTS TO LIFT NORTH/NW. UNTIL THIS
TRANSITION THOUGH OUR WINDS WILL STRUGGLE TO VEER AROUND...AS SPEEDS
HOLD NEAR OR BELOW 15 KT AND SEAS ARE LIMITED TO 3 OR 4 FT.

TUESDAY NIGHT AND WEDNESDAY...FINALLY THE COASTAL WARM FRONT WILL
SHIFT NORTH OF THE LOCAL WATERS TUESDAY NIGHT AS A STRONG COLD FRONT
MOVES THROUGH WEDNESDAY. WARM ADVECTION AND THE RESULTING
MARINE-LAYERING EFFECTS WILL LIMIT THE STRENGTH OF WINDS AHEAD OF
THE FRONT...BUT SMALL CRAFT ADVISORIES ARE CERTAINLY POSSIBLE.
BEHIND THE FRONT THE COMBINATION OF COLD ADVECTION AND STRONG
ISALLOBARIC PRESSURE RISES MAY SUPPORT GALES...OR AT THE LEAST SMALL
CRAFT ADVISORIES. MARINERS ARE ALSO ADVISED THAT SOME STRONGER
T-STORMS ARE POSSIBLE IN ADVANCE OF THE COLD FRONT...CAPABLE OF
PRODUCING GUSTY WINDS AND LIGHTNING STRIKES.

THURSDAY...CONDITIONS WILL IMPROVE OVER ALL WATERS AS HIGH PRESSURE
BECOMES CENTERED JUST SOUTH OF THE AREA. WINDS/SEAS SHOULD
EVENTUALLY LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL MARINE
ZONES AS COLD ADVECTION WANES AND THE GRADIENT RELAXES.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
INTO TUESDAY. ACTUAL SEA FOG MAY HAVE A WINDOW TO DEVELOP AS
SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE TUESDAY INTO TUESDAY NIGHT
PRIOR TO WINDS INCREASING ENOUGH TO SCOUR IT OUT WEDNESDAY. NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...GIVEN
THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AN INCREASING
RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY AROUND THE TIME
OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE FURTHER EXACERBATED
DUE TO STEADY RAINS PRIOR TO AND DURING THE HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...DPB
AVIATION...33/SPR
MARINE...33/SPR
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 210312
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1012 PM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED OVERNIGHT THROUGH TUESDAY AS
SEVERAL DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT
WILL APPROACH LATE TUESDAY NIGHT...THEN SHIFT THROUGH THE AREA ON
WEDNESDAY. DRY HIGH PRESSURE WILL THEN SETTLE OVER THE SOUTHEAST
THROUGH LATE WEEK...WITH A COLD FRONT EXPECTED NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LATE SATURDAY EVENING...SATELLITE IMAGERY AND AREA RADAR TRENDS
CONTINUED TO DEPICT A WEAK SHORTWAVE TROUGH ALOFT AND ASSOCIATED
AREAS OF LIGHT RAIN EJECTING ENE TOWARD THE AREA. INITIALLY...
POPS GRADUATED FROM HIGH CHANCE ALONG/SOUTH OF INTERSTATE 16 TO
BELOW 15 PERCENT ACROSS FAR NORTHERN COUNTIES WILL SUFFICE AS
MID/UPPER LEVEL DRY AIR HAS TEMPORARILY OVERSPREAD THE REGION AS
SHOWN BY THE 00Z KCHS SOUNDING AND WATER VAPOR IMAGERY. ALSO...
RECENT SURFACE OBSERVATIONS SUGGEST THAT PRECIPITATION THUS FAR
HAS REMAINED LIGHT. HOWEVER...AS THE NIGHT PROGRESSES...MODEL
CONSENSUS INCLUDING RECENT HIGH RESOLUTION SOLUTIONS SUGGEST THAT
PRECIPITATION COVERAGE WILL INCREASE. ACCORDINGLY...RAMPED UP POPS
OVERNIGHT...EVENTUALLY TAPERED FROM LIKELY/HIGH CHANCE ACROSS
SOUTHERN AND COASTAL COUNTIES TO CHANCE INLAND. GIVEN THE MOST
RECENT RUC13 AND HRRR GUIDANCE...LIGHT RAIN YET BECOME MORE
WIDESPREAD THAN INDICATED WITHIN THE LATE EVENING UPDATE...AND
HIGHER POPS COULD BE REQUIRED WITHIN SUBSEQUENT FORECASTS.

MEANWHILE...WITHIN THE WEDGE REGIME STRATUS COULD PRODUCE SOME
DRIZZLE AND COULD LOWER TOWARD THE SURFACE TO SUPPORT FOG
OVERNIGHT. NEAR THE COAST...PERSISTENT SURFACE WINDS SHOULD
LIMIT THE POTENTIAL FOR SIGNIFICANT DENSE FOG OVERNIGHT...ALTHOUGH
CEILINGS COULD OCCASIONALLY LOWER TO PRODUCE REDUCED VISIBILITY.
FARTHER INLAND...SLIGHTLY HIGHER ELEVATIONS AND LIGHTER WINDS
COULD ENHANCE THE POTENTIAL FOR LOCALLY DENSE FOG.

OTHERWISE...TEMPERATURES WILL FALL ONLY SLOWLY OVERNIGHT AND BY
DAYBREAK WILL RANGE FROM THE LOWER TO MID 40S NORTH TO THE UPPER
40S/LOWER 50S SOUTH AND ON THE COAST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...A WEAK SOUTHERN STREAM MID LEVEL PERTURBATION MOVING
THROUGH THE LOWER MS VALLEY FROM TONIGHT WILL CROSS THE AREA DURING
THE MORNING HOURS AND REINFORCES THE PRE-EXISTING STATIONARY FRONT
OVER THE ATLANTIC TO THE EAST/SE OF THE GULF STREAM. IT ALSO KEEPS
THE INLAND COOL HIGH PRESSURE WEDGE ANCHORED IN PLACE AS IT EXTENDS
SOUTH OF THE FORECAST AREA. THE IMPULSE ALOFT ALSO TRIGGERS WEAK
CYCLOGENESIS OFF THE SE COAST SOME 250 NM EAST OF SAVANNAH AS IT
MOVES LITTLE THROUGHOUT THE DAY. ISENTROPIC ASCENT WILL AGAIN BE THE
MAIN FACTOR FOR GENERATING RAINFALL...AS IT INCREASES IN MAGNITUDE
DURING THE AFTERNOON AND EVENING HOURS...AND POPS ACCORDINGLY WILL
BE ON THE INCREASE AS WELL DURING THE SECOND HALF OF THE DAY. WE/LL
START THE PERIOD WITH A LITTLE LIGHT RAIN...DRIZZLE AND/OR FOG
BEFORE POPS CLIMB INTO THE 30-50 PERCENTILE IN THE AFTERNOON.
GREATEST PROBABILITIES WILL BE OVER SE GA AND ESPECIALLY SOUTH OF
I-16 DURING THAT TIME. OVERCAST SKIES AND A CONTINUED FEED OF AIR
FROM THE NORTH/NE WITHIN THE LOW LEVEL WEDGE WILL KEEP TEMPS DOWN
MAINLY INTO THE 50S FOR MAX TEMPS.

SUNDAY NIGHT INTO MONDAY...ANOTHER AND SLIGHTLY STRONGER SHORT WAVE
ARRIVES FROM THE GULF OF MEXICO AND FORCES THE ATLANTIC WAVE TO
DEEPEN A FEW MILLIBARS AS IT LIFTS NE ROUGHLY ALONG THE GULF STREAM
TO A POSITION OFF CAPE HATTERAS BY 00Z TUESDAY. THIS PATTERN
REINFORCES THE WEDGE INLAND...WHICH IN TURN ALLOWS FOR A FURTHER
INCREASE IN ISENTROPIC ASCENT. THAT ALONG WITH FORCING FROM THE
UPPER JET OVER THE SE CORNER OF THE COUNTRY AND CONVERGENCE
ASSOCIATED WITH THE NEARBY ATLANTIC LOW WILL CAUSE COVERAGE OF RAIN
TO EXPAND INTO AT LEAST THE 70-80 PERCENT RANGE SUNDAY
NIGHT...BEFORE COVERAGE DIMINISHES FROM WEST TO EST ON MONDAY AS THE
SURFACE LOW PULLS AWAY. PWATS OF 1.3 TO 1.4 INCHES AND THE FLOW
ALOFT OPENING MORE OUT OF THE GULF OF MEXICO SUPPORTS AT LEAST 1/4
TO 1/2 INCH AMOUNTS OF RAIN. IN ADDITION...STEEPER MID LEVEL LAPSE
RATES AND SHOWALTER INDICES DROPPING TO NEAR ZERO COULD SUPPORT A
LITTLE ELEVATED CONVECTION. LOW STRATUS DECKS WILL ALSO SUPPORT SOME
REDUCTION IN SURFACE VISIBILITIES SUNDAY NIGHT INTO MONDAY MORNING
AND WE HAVE ADDED PATCHY FOG TO THE FORECAST. THERE IS ONLY A SMALL
5-10 DEGREE TEMP SWING FROM DAYTIME HIGHS SUNDAY TO NIGHTTIME LOWS
SUNDAY NIGHT. THEN A FAIRLY LARGE NORTH/NW TO SOUTH/SE TEMP GRADIENT
MONDAY WITH HIGHS NEAR OR SLIGHTLY BELOW NORMAL.

MONDAY NIGHT AND TUESDAY...YET ANOTHER QUICK MOVING SOUTHERN STREAM
SHORT WAVE ARRIVES LATE MONDAY NIGHT AND TUESDAY FROM THE GULF OF
MEXICO. FURTHER UPSTREAM A MORE PRONOUNCED SHORT WAVE STARTS TO DIG
THROUGH THE CENTRAL STATES...WHICH IN TURN AMPLIFIES THE LARGE SCALE
PATTERN ACROSS THE CONUS. THIS BACKS OUR FLOW ALOFT FURTHER TO THE
SW AND OPENS THE DOOR FOR A FEED OF EVEN DEEPER AND TROPICAL-LIKE
MOISTURE TO MOVE IN. PWATS CLIMB TO NEAR 2 STANDARD DEVIATIONS ABOVE
NORMAL...AROUND 1.6 TO 1.7 INCHES SO YET ANOTHER ROUND OF RAINFALL
WILL OCCUR. POPS WILL BE IN THE CHANCE TO LIKELY RANGE MONDAY NIGHT
THEN SHOULD PEAK IN THE CATEGORICAL RANGE TUESDAY. ADDITIONAL QPF
WILL BE AT LEAST 1/2 TO 3/4 INCHES...WITH POTENTIAL HIGHER AMOUNTS
IN THIS PATTERN. THE SHORT WAVE IN THE PLAINS WILL ALSO TRIGGER
CYCLOGENESIS NEAR THE ARKLATEX REGION BY TUESDAY...WHICH IN TURN
ATTEMPTS TO LIFT OUR COASTAL WARM FRONT NORTHWARD. NOT SURE HOW THIS
PROGRESSION WILL ACTUAL PAN OUT GIVEN THAT THE INLAND WEDGE WILL BE
RELUCTANT TO GIVE UP ITS HOLD. THIS WILL ALLOW FOR WARM ADVECTION TO
BOOST TEMPS AT LEAST INTO THE LOWER OR MIDDLE 60S...PERHAPS EVEN
HIGHER NEAR THE ALTAMAHA. THIS IN TURN CREATES SOME SURFACE BASED
INSTABILITY ON THE ORDER OF 500-800 J/KG IN SYNC WITH STEEP MID
LEVEL LAPSE RATES OVER OUR COASTAL ZONES AND SOUTH OF I-16. IT/S IN
THESE AREAS WHERE WE HAVE ISOLATED T-STORMS MENTIONED IN THE LATEST
FORECAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
DO NOT EXPECTED IMPROVEMENT BEYOND MVFR CEILINGS TONIGHT AND
SUNDAY...AND IFR/LIFR CEILINGS WILL PREVAIL MUCH OF THE TIME THIS
EVENING INTO SUNDAY MORNING. PREVALENCE OF LIGHT RAIN REMAINS
SOMEWHAT UNCERTAIN AS ADDITIONAL WAVES PUSH E/NE INTO THE REGION
OVERNIGHT AND AGAIN SUNDAY. HIGHEST POPS SHOULD OCCUR AT KSAV
TONIGHT...ALTHOUGH RAIN COULD EXPAND INTO THE KCHS AREA. EVEN IF A
BREAK IN PRECIPITATION DEVELOPS LATE TONIGHT INTO SUNDAY MORNING...
ANOTHER ROUND OF RAIN SHOULD COMMENCE AT BOTH SITES SUNDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH EARLY TUESDAY
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON AS A STRONG COLD FRONT APPROACHES FROM THE
WEST WITH SHOWERS AND POSSIBLY THUNDERSTORMS. WINDY CONDITIONS
SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
OVERNIGHT...MARINE LAYER MIXING AND A TIGHT SURFACE PRESSURE
GRADIENT BETWEEN AN INLAND WEDGE OF HIGH PRESSURE AND A TROUGH OF
LOW PRESSURE OVER THE GULF STREAM WILL MAINTAIN ELEVATED NORTHEAST
WINDS...AS HIGH AS 15-20 KT...AND ASSOCIATED SEAS 3-5 FT...HIGHEST
BEYOND 20 NM. OVERALL...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY LEVELS.

SUNDAY...A PINCHED PRESSURE GRADIENT BETWEEN DEVELOPING LOW PRESSURE
OFF THE GA COAST NEAR THE GULF STREAM AND A STRONG INLAND WEDGE OF
HIGH PRESSURE WILL PERSIST. THIS WILL RESULT IN NORTH/NE WINDS OF AT
LEAST 15-20 KT...WITH GUSTS AT TIMES TO NEAR 25 KT. IF THE GUSTS
BECOME FREQUENT ENOUGH WE/D NEED A SMALL CRAFT ADVISORY...WHICH
WE/LL DEFER TO FUTURE SHIFTS TO SEE IF WE INDEED SHOULD HOIST THE
ADVISORY HEADLINE. THE FETCH IS FAVORABLE ENOUGH FOR SEAS TO BE AS
HIGH AS 3-5 FT...GREATEST OVER AMZ374 AND THE EASTERNMOST PARTS OF
AMZ350.

SUNDAY NIGHT AND MONDAY...THE ATLANTIC WAVE DEEPENS SOME AS IT LIFTS
NE ALONG THE GULF STREAM...WHILE THE INLAND WEDGE HOLDS FIRM. THE
GRADIENT THOUGH DOES SLACKEN SOME OF THE LOW SHIFTS NORTH OF THE
LOCAL WATERS...AND WINDS AND SEAS WILL BE LESS AND BELOW ANY
ADVISORY CRITERIA.

MONDAY NIGHT AND TUESDAY...THE INLAND WEDGE IS STILL IN PLACE DURING
MUCH OF THE PERIOD...BUT IT DOES ATTEMPT TO ERODE BY TUESDAY NIGHT
AS THE COASTAL WARM FRONT STARTS TO LIFT NORTH/NW. UNTIL THIS
TRANSITION THOUGH OUR WINDS WILL STRUGGLE TO VEER AROUND...AS SPEEDS
HOLD NEAR OR BELOW 15 KT AND SEAS ARE LIMITED TO 3 OR 4 FT.

TUESDAY NIGHT AND WEDNESDAY...FINALLY THE COASTAL WARM FRONT WILL
SHIFT NORTH OF THE LOCAL WATERS TUESDAY NIGHT AS A STRONG COLD FRONT
MOVES THROUGH WEDNESDAY. WARM ADVECTION AND THE RESULTING
MARINE-LAYERING EFFECTS WILL LIMIT THE STRENGTH OF WINDS AHEAD OF
THE FRONT...BUT SMALL CRAFT ADVISORIES ARE CERTAINLY POSSIBLE.
BEHIND THE FRONT THE COMBINATION OF COLD ADVECTION AND STRONG
ISALLOBARIC PRESSURE RISES MAY SUPPORT GALES...OR AT THE LEAST SMALL
CRAFT ADVISORIES. MARINERS ARE ALSO ADVISED THAT SOME STRONGER
T-STORMS ARE POSSIBLE IN ADVANCE OF THE COLD FRONT...CAPABLE OF
PRODUCING GUSTY WINDS AND LIGHTNING STRIKES.

THURSDAY...CONDITIONS WILL IMPROVE OVER ALL WATERS AS HIGH PRESSURE
BECOMES CENTERED JUST SOUTH OF THE AREA. WINDS/SEAS SHOULD
EVENTUALLY LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL MARINE
ZONES AS COLD ADVECTION WANES AND THE GRADIENT RELAXES.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
INTO TUESDAY. ACTUAL SEA FOG MAY HAVE A WINDOW TO DEVELOP AS
SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE TUESDAY INTO TUESDAY NIGHT
PRIOR TO WINDS INCREASING ENOUGH TO SCOUR IT OUT WEDNESDAY. NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...GIVEN
THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AN INCREASING
RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY AROUND THE TIME
OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE FURTHER EXACERBATED
DUE TO STEADY RAINS PRIOR TO AND DURING THE HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...DPB
AVIATION...33/SPR
MARINE...33/SPR
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 202359
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
659 PM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH LATE TUESDAY
NIGHT...THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE
WILL THEN SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK...WITH A COLD
FRONT EXPECTED NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SATURDAY EVENING...SATELLITE IMAGERY AND AREA RADAR TRENDS
DEPICTED ANOTHER WAVE AND ASSOCIATED EXPANDING COVERAGE OF LIGHT
RAIN EJECTING ENE TOWARD THE AREA. ACCORDINGLY...RAISED POPS TO
HIGH CHANCE ESPECIALLY ALONG/S OF I-16 AND ALONG THE IMMEDIATE
COAST...TAPERED TO CHANCE/SLIGHT CHANCE FARTHER N/NW. RECENT HIGH
RESOLUTION GUIDANCE...ESPECIALLY THE HRRR...SUGGESTS THAT LIGHT
RAIN COULD BECOME WIDESPREAD AND THAT HIGHER POPS COULD BE
REQUIRED WITHIN SUBSEQUENT FORECASTS.

OTHERWISE...PER ONGOING/EXPECTED TRENDS SLOWED THE RATE OF
TEMPERATURE DECREASE TONIGHT. WITHIN THE WEDGE REGIME...STRATUS
COULD PRODUCE SOME DRIZZLE AND COULD LOWER TOWARD THE SURFACE TO
SUPPORT AT LEAST PATCHY FOG OVERNIGHT. PERSISTENT SURFACE WINDS
SHOULD LIMIT THE POTENTIAL FOR SIGNIFICANT DENSE FOG
OVERNIGHT...WILL CONTINUE TO ASSESS.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...A WEAK SOUTHERN STREAM MID LEVEL PERTURBATION MOVING
THROUGH THE LOWER MS VALLEY FROM TONIGHT WILL CROSS THE AREA DURING
THE MORNING HOURS AND REINFORCES THE PRE-EXISTING STATIONARY FRONT
OVER THE ATLANTIC TO THE EAST/SE OF THE GULF STREAM. IT ALSO KEEPS
THE INLAND COOL HIGH PRESSURE WEDGE ANCHORED IN PLACE AS IT EXTENDS
SOUTH OF THE FORECAST AREA. THE IMPULSE ALOFT ALSO TRIGGERS WEAK
CYCLOGENESIS OFF THE SE COAST SOME 250 NM EAST OF SAVANNAH AS IT
MOVES LITTLE THROUGHOUT THE DAY. ISENTROPIC ASCENT WILL AGAIN BE THE
MAIN FACTOR FOR GENERATING RAINFALL...AS IT INCREASES IN MAGNITUDE
DURING THE AFTERNOON AND EVENING HOURS...AND POPS ACCORDINGLY WILL
BE ON THE INCREASE AS WELL DURING THE SECOND HALF OF THE DAY. WE/LL
START THE PERIOD WITH A LITTLE LIGHT RAIN...DRIZZLE AND/OR FOG
BEFORE POPS CLIMB INTO THE 30-50 PERCENTILE IN THE AFTERNOON.
GREATEST PROBABILITIES WILL BE OVER SE GA AND ESPECIALLY SOUTH OF
I-16 DURING THAT TIME. OVERCAST SKIES AND A CONTINUED FEED OF AIR
FROM THE NORTH/NE WITHIN THE LOW LEVEL WEDGE WILL KEEP TEMPS DOWN
MAINLY INTO THE 50S FOR MAX TEMPS.

SUNDAY NIGHT INTO MONDAY...ANOTHER AND SLIGHTLY STRONGER SHORT WAVE
ARRIVES FROM THE GULF OF MEXICO AND FORCES THE ATLANTIC WAVE TO
DEEPEN A FEW MILLIBARS AS IT LIFTS NE ROUGHLY ALONG THE GULF STREAM
TO A POSITION OFF CAPE HATTERAS BY 00Z TUESDAY. THIS PATTERN
REINFORCES THE WEDGE INLAND...WHICH IN TURN ALLOWS FOR A FURTHER
INCREASE IN ISENTROPIC ASCENT. THAT ALONG WITH FORCING FROM THE
UPPER JET OVER THE SE CORNER OF THE COUNTRY AND CONVERGENCE
ASSOCIATED WITH THE NEARBY ATLANTIC LOW WILL CAUSE COVERAGE OF RAIN
TO EXPAND INTO AT LEAST THE 70-80 PERCENT RANGE SUNDAY
NIGHT...BEFORE COVERAGE DIMINISHES FROM WEST TO EST ON MONDAY AS THE
SURFACE LOW PULLS AWAY. PWATS OF 1.3 TO 1.4 INCHES AND THE FLOW
ALOFT OPENING MORE OUT OF THE GULF OF MEXICO SUPPORTS AT LEAST 1/4
TO 1/2 INCH AMOUNTS OF RAIN. IN ADDITION...STEEPER MID LEVEL LAPSE
RATES AND SHOWALTER INDICES DROPPING TO NEAR ZERO COULD SUPPORT A
LITTLE ELEVATED CONVECTION. LOW STRATUS DECKS WILL ALSO SUPPORT SOME
REDUCTION IN SURFACE VISIBILITIES SUNDAY NIGHT INTO MONDAY MORNING
AND WE HAVE ADDED PATCHY FOG TO THE FORECAST. THERE IS ONLY A SMALL
5-10 DEGREE TEMP SWING FROM DAYTIME HIGHS SUNDAY TO NIGHTTIME LOWS
SUNDAY NIGHT. THEN A FAIRLY LARGE NORTH/NW TO SOUTH/SE TEMP GRADIENT
MONDAY WITH HIGHS NEAR OR SLIGHTLY BELOW NORMAL.

MONDAY NIGHT AND TUESDAY...YET ANOTHER QUICK MOVING SOUTHERN STREAM
SHORT WAVE ARRIVES LATE MONDAY NIGHT AND TUESDAY FROM THE GULF OF
MEXICO. FURTHER UPSTREAM A MORE PRONOUNCED SHORT WAVE STARTS TO DIG
THROUGH THE CENTRAL STATES...WHICH IN TURN AMPLIFIES THE LARGE SCALE
PATTERN ACROSS THE CONUS. THIS BACKS OUR FLOW ALOFT FURTHER TO THE
SW AND OPENS THE DOOR FOR A FEED OF EVEN DEEPER AND TROPICAL-LIKE
MOISTURE TO MOVE IN. PWATS CLIMB TO NEAR 2 STANDARD DEVIATIONS ABOVE
NORMAL...AROUND 1.6 TO 1.7 INCHES SO YET ANOTHER ROUND OF RAINFALL
WILL OCCUR. POPS WILL BE IN THE CHANCE TO LIKELY RANGE MONDAY NIGHT
THEN SHOULD PEAK IN THE CATEGORICAL RANGE TUESDAY. ADDITIONAL QPF
WILL BE AT LEAST 1/2 TO 3/4 INCHES...WITH POTENTIAL HIGHER AMOUNTS
IN THIS PATTERN. THE SHORT WAVE IN THE PLAINS WILL ALSO TRIGGER
CYCLOGENESIS NEAR THE ARKLATEX REGION BY TUESDAY...WHICH IN TURN
ATTEMPTS TO LIFT OUR COASTAL WARM FRONT NORTHWARD. NOT SURE HOW THIS
PROGRESSION WILL ACTUAL PAN OUT GIVEN THAT THE INLAND WEDGE WILL BE
RELUCTANT TO GIVE UP ITS HOLD. THIS WILL ALLOW FOR WARM ADVECTION TO
BOOST TEMPS AT LEAST INTO THE LOWER OR MIDDLE 60S...PERHAPS EVEN
HIGHER NEAR THE ALTAMAHA. THIS IN TURN CREATES SOME SURFACE BASED
INSTABILITY ON THE ORDER OF 500-800 J/KG IN SYNC WITH STEEP MID
LEVEL LAPSE RATES OVER OUR COASTAL ZONES AND SOUTH OF I-16. IT/S IN
THESE AREAS WHERE WE HAVE ISOLATED T-STORMS MENTIONED IN THE LATEST
FORECAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
DO NOT EXPECTED IMPROVEMENT BEYOND MVFR CEILINGS TONIGHT AND
SUNDAY...AND IFR/LIFR CEILINGS WILL PREVAIL MUCH OF THE TIME THIS
EVENING INTO SUNDAY MORNING. PREVALENCE OF LIGHT RAIN REMAINS
SOMEWHAT UNCERTAIN AS ADDITIONAL WAVES PUSH E/NE INTO THE REGION
OVERNIGHT AND AGAIN SUNDAY. HIGHEST POPS SHOULD OCCUR AT KSAV
TONIGHT...ALTHOUGH RAIN COULD EXPAND INTO THE KCHS AREA. EVEN IF A
BREAK IN PRECIPITATION DEVELOPS LATE TONIGHT INTO SUNDAY MORNING...
ANOTHER ROUND OF RAIN SHOULD COMMENCE AT BOTH SITES SUNDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH EARLY TUESDAY
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON AS A STRONG COLD FRONT APPROACHES FROM THE
WEST WITH SHOWERS AND POSSIBLY THUNDERSTORMS. WINDY CONDITIONS
SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
THE TIGHT NORTHEAST GRADIENT WILL PERSIST THROUGH TONIGHT AS HIGH
PRESSURE CONTINUES TO WEDGE DOWN THE EASTERN SEABOARD AND LOW
PRESSURE SPINS OFF THE SC COAST. A STEADY 15-20 KT WIND EXPECTED
OVER MOST OF THE MARINE AREA OVERNIGHT WITH SEAS 3-5 FT...HIGHEST
BEYOND 20 NM.

SUNDAY...A PINCHED PRESSURE GRADIENT BETWEEN DEVELOPING LOW PRESSURE
OFF THE GA COAST NEAR THE GULF STREAM AND A STRONG INLAND WEDGE OF
HIGH PRESSURE WILL PERSIST. THIS WILL RESULT IN NORTH/NE WINDS OF AT
LEAST 15-20 KT...WITH GUSTS AT TIMES TO NEAR 25 KT. IF THE GUSTS
BECOME FREQUENT ENOUGH WE/D NEED A SMALL CRAFT ADVISORY...WHICH
WE/LL DEFER TO FUTURE SHIFTS TO SEE IF WE INDEED SHOULD HOIST THE
ADVISORY HEADLINE. THE FETCH IS FAVORABLE ENOUGH FOR SEAS TO BE AS
HIGH AS 3-5 FT...GREATEST OVER AMZ374 AND THE EASTERNMOST PARTS OF
AMZ350.

SUNDAY NIGHT AND MONDAY...THE ATLANTIC WAVE DEEPENS SOME AS IT LIFTS
NE ALONG THE GULF STREAM...WHILE THE INLAND WEDGE HOLDS FIRM. THE
GRADIENT THOUGH DOES SLACKEN SOME OF THE LOW SHIFTS NORTH OF THE
LOCAL WATERS...AND WINDS AND SEAS WILL BE LESS AND BELOW ANY
ADVISORY CRITERIA.

MONDAY NIGHT AND TUESDAY...THE INLAND WEDGE IS STILL IN PLACE DURING
MUCH OF THE PERIOD...BUT IT DOES ATTEMPT TO ERODE BY TUESDAY NIGHT
AS THE COASTAL WARM FRONT STARTS TO LIFT NORTH/NW. UNTIL THIS
TRANSITION THOUGH OUR WINDS WILL STRUGGLE TO VEER AROUND...AS SPEEDS
HOLD NEAR OR BELOW 15 KT AND SEAS ARE LIMITED TO 3 OR 4 FT.

TUESDAY NIGHT AND WEDNESDAY...FINALLY THE COASTAL WARM FRONT WILL
SHIFT NORTH OF THE LOCAL WATERS TUESDAY NIGHT AS A STRONG COLD FRONT
MOVES THROUGH WEDNESDAY. WARM ADVECTION AND THE RESULTING
MARINE-LAYERING EFFECTS WILL LIMIT THE STRENGTH OF WINDS AHEAD OF
THE FRONT...BUT SMALL CRAFT ADVISORIES ARE CERTAINLY POSSIBLE.
BEHIND THE FRONT THE COMBINATION OF COLD ADVECTION AND STRONG
ISALLOBARIC PRESSURE RISES MAY SUPPORT GALES...OR AT THE LEAST SMALL
CRAFT ADVISORIES. MARINERS ARE ALSO ADVISED THAT SOME STRONGER
T-STORMS ARE POSSIBLE IN ADVANCE OF THE COLD FRONT...CAPABLE OF
PRODUCING GUSTY WINDS AND LIGHTNING STRIKES.

THURSDAY...CONDITIONS WILL IMPROVE OVER ALL WATERS AS HIGH PRESSURE
BECOMES CENTERED JUST SOUTH OF THE AREA. WINDS/SEAS SHOULD
EVENTUALLY LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL MARINE
ZONES AS COLD ADVECTION WANES AND THE GRADIENT RELAXES.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
INTO TUESDAY. ACTUAL SEA FOG MAY HAVE A WINDOW TO DEVELOP AS
SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE TUESDAY INTO TUESDAY NIGHT
PRIOR TO WINDS INCREASING ENOUGH TO SCOUR IT OUT WEDNESDAY. NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...GIVEN
THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AN INCREASING
RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY AROUND THE TIME
OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE FURTHER EXACERBATED
DUE TO STEADY RAINS PRIOR TO AND DURING THE HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...JRL/SPR
SHORT TERM...33
LONG TERM...DPB
AVIATION...33/JRL/SPR
MARINE...33/JRL/SPR
TIDES/COASTAL FLOODING...33







000
FXUS62 KCHS 202359
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
659 PM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH LATE TUESDAY
NIGHT...THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE
WILL THEN SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK...WITH A COLD
FRONT EXPECTED NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SATURDAY EVENING...SATELLITE IMAGERY AND AREA RADAR TRENDS
DEPICTED ANOTHER WAVE AND ASSOCIATED EXPANDING COVERAGE OF LIGHT
RAIN EJECTING ENE TOWARD THE AREA. ACCORDINGLY...RAISED POPS TO
HIGH CHANCE ESPECIALLY ALONG/S OF I-16 AND ALONG THE IMMEDIATE
COAST...TAPERED TO CHANCE/SLIGHT CHANCE FARTHER N/NW. RECENT HIGH
RESOLUTION GUIDANCE...ESPECIALLY THE HRRR...SUGGESTS THAT LIGHT
RAIN COULD BECOME WIDESPREAD AND THAT HIGHER POPS COULD BE
REQUIRED WITHIN SUBSEQUENT FORECASTS.

OTHERWISE...PER ONGOING/EXPECTED TRENDS SLOWED THE RATE OF
TEMPERATURE DECREASE TONIGHT. WITHIN THE WEDGE REGIME...STRATUS
COULD PRODUCE SOME DRIZZLE AND COULD LOWER TOWARD THE SURFACE TO
SUPPORT AT LEAST PATCHY FOG OVERNIGHT. PERSISTENT SURFACE WINDS
SHOULD LIMIT THE POTENTIAL FOR SIGNIFICANT DENSE FOG
OVERNIGHT...WILL CONTINUE TO ASSESS.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...A WEAK SOUTHERN STREAM MID LEVEL PERTURBATION MOVING
THROUGH THE LOWER MS VALLEY FROM TONIGHT WILL CROSS THE AREA DURING
THE MORNING HOURS AND REINFORCES THE PRE-EXISTING STATIONARY FRONT
OVER THE ATLANTIC TO THE EAST/SE OF THE GULF STREAM. IT ALSO KEEPS
THE INLAND COOL HIGH PRESSURE WEDGE ANCHORED IN PLACE AS IT EXTENDS
SOUTH OF THE FORECAST AREA. THE IMPULSE ALOFT ALSO TRIGGERS WEAK
CYCLOGENESIS OFF THE SE COAST SOME 250 NM EAST OF SAVANNAH AS IT
MOVES LITTLE THROUGHOUT THE DAY. ISENTROPIC ASCENT WILL AGAIN BE THE
MAIN FACTOR FOR GENERATING RAINFALL...AS IT INCREASES IN MAGNITUDE
DURING THE AFTERNOON AND EVENING HOURS...AND POPS ACCORDINGLY WILL
BE ON THE INCREASE AS WELL DURING THE SECOND HALF OF THE DAY. WE/LL
START THE PERIOD WITH A LITTLE LIGHT RAIN...DRIZZLE AND/OR FOG
BEFORE POPS CLIMB INTO THE 30-50 PERCENTILE IN THE AFTERNOON.
GREATEST PROBABILITIES WILL BE OVER SE GA AND ESPECIALLY SOUTH OF
I-16 DURING THAT TIME. OVERCAST SKIES AND A CONTINUED FEED OF AIR
FROM THE NORTH/NE WITHIN THE LOW LEVEL WEDGE WILL KEEP TEMPS DOWN
MAINLY INTO THE 50S FOR MAX TEMPS.

SUNDAY NIGHT INTO MONDAY...ANOTHER AND SLIGHTLY STRONGER SHORT WAVE
ARRIVES FROM THE GULF OF MEXICO AND FORCES THE ATLANTIC WAVE TO
DEEPEN A FEW MILLIBARS AS IT LIFTS NE ROUGHLY ALONG THE GULF STREAM
TO A POSITION OFF CAPE HATTERAS BY 00Z TUESDAY. THIS PATTERN
REINFORCES THE WEDGE INLAND...WHICH IN TURN ALLOWS FOR A FURTHER
INCREASE IN ISENTROPIC ASCENT. THAT ALONG WITH FORCING FROM THE
UPPER JET OVER THE SE CORNER OF THE COUNTRY AND CONVERGENCE
ASSOCIATED WITH THE NEARBY ATLANTIC LOW WILL CAUSE COVERAGE OF RAIN
TO EXPAND INTO AT LEAST THE 70-80 PERCENT RANGE SUNDAY
NIGHT...BEFORE COVERAGE DIMINISHES FROM WEST TO EST ON MONDAY AS THE
SURFACE LOW PULLS AWAY. PWATS OF 1.3 TO 1.4 INCHES AND THE FLOW
ALOFT OPENING MORE OUT OF THE GULF OF MEXICO SUPPORTS AT LEAST 1/4
TO 1/2 INCH AMOUNTS OF RAIN. IN ADDITION...STEEPER MID LEVEL LAPSE
RATES AND SHOWALTER INDICES DROPPING TO NEAR ZERO COULD SUPPORT A
LITTLE ELEVATED CONVECTION. LOW STRATUS DECKS WILL ALSO SUPPORT SOME
REDUCTION IN SURFACE VISIBILITIES SUNDAY NIGHT INTO MONDAY MORNING
AND WE HAVE ADDED PATCHY FOG TO THE FORECAST. THERE IS ONLY A SMALL
5-10 DEGREE TEMP SWING FROM DAYTIME HIGHS SUNDAY TO NIGHTTIME LOWS
SUNDAY NIGHT. THEN A FAIRLY LARGE NORTH/NW TO SOUTH/SE TEMP GRADIENT
MONDAY WITH HIGHS NEAR OR SLIGHTLY BELOW NORMAL.

MONDAY NIGHT AND TUESDAY...YET ANOTHER QUICK MOVING SOUTHERN STREAM
SHORT WAVE ARRIVES LATE MONDAY NIGHT AND TUESDAY FROM THE GULF OF
MEXICO. FURTHER UPSTREAM A MORE PRONOUNCED SHORT WAVE STARTS TO DIG
THROUGH THE CENTRAL STATES...WHICH IN TURN AMPLIFIES THE LARGE SCALE
PATTERN ACROSS THE CONUS. THIS BACKS OUR FLOW ALOFT FURTHER TO THE
SW AND OPENS THE DOOR FOR A FEED OF EVEN DEEPER AND TROPICAL-LIKE
MOISTURE TO MOVE IN. PWATS CLIMB TO NEAR 2 STANDARD DEVIATIONS ABOVE
NORMAL...AROUND 1.6 TO 1.7 INCHES SO YET ANOTHER ROUND OF RAINFALL
WILL OCCUR. POPS WILL BE IN THE CHANCE TO LIKELY RANGE MONDAY NIGHT
THEN SHOULD PEAK IN THE CATEGORICAL RANGE TUESDAY. ADDITIONAL QPF
WILL BE AT LEAST 1/2 TO 3/4 INCHES...WITH POTENTIAL HIGHER AMOUNTS
IN THIS PATTERN. THE SHORT WAVE IN THE PLAINS WILL ALSO TRIGGER
CYCLOGENESIS NEAR THE ARKLATEX REGION BY TUESDAY...WHICH IN TURN
ATTEMPTS TO LIFT OUR COASTAL WARM FRONT NORTHWARD. NOT SURE HOW THIS
PROGRESSION WILL ACTUAL PAN OUT GIVEN THAT THE INLAND WEDGE WILL BE
RELUCTANT TO GIVE UP ITS HOLD. THIS WILL ALLOW FOR WARM ADVECTION TO
BOOST TEMPS AT LEAST INTO THE LOWER OR MIDDLE 60S...PERHAPS EVEN
HIGHER NEAR THE ALTAMAHA. THIS IN TURN CREATES SOME SURFACE BASED
INSTABILITY ON THE ORDER OF 500-800 J/KG IN SYNC WITH STEEP MID
LEVEL LAPSE RATES OVER OUR COASTAL ZONES AND SOUTH OF I-16. IT/S IN
THESE AREAS WHERE WE HAVE ISOLATED T-STORMS MENTIONED IN THE LATEST
FORECAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
DO NOT EXPECTED IMPROVEMENT BEYOND MVFR CEILINGS TONIGHT AND
SUNDAY...AND IFR/LIFR CEILINGS WILL PREVAIL MUCH OF THE TIME THIS
EVENING INTO SUNDAY MORNING. PREVALENCE OF LIGHT RAIN REMAINS
SOMEWHAT UNCERTAIN AS ADDITIONAL WAVES PUSH E/NE INTO THE REGION
OVERNIGHT AND AGAIN SUNDAY. HIGHEST POPS SHOULD OCCUR AT KSAV
TONIGHT...ALTHOUGH RAIN COULD EXPAND INTO THE KCHS AREA. EVEN IF A
BREAK IN PRECIPITATION DEVELOPS LATE TONIGHT INTO SUNDAY MORNING...
ANOTHER ROUND OF RAIN SHOULD COMMENCE AT BOTH SITES SUNDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH EARLY TUESDAY
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON AS A STRONG COLD FRONT APPROACHES FROM THE
WEST WITH SHOWERS AND POSSIBLY THUNDERSTORMS. WINDY CONDITIONS
SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
THE TIGHT NORTHEAST GRADIENT WILL PERSIST THROUGH TONIGHT AS HIGH
PRESSURE CONTINUES TO WEDGE DOWN THE EASTERN SEABOARD AND LOW
PRESSURE SPINS OFF THE SC COAST. A STEADY 15-20 KT WIND EXPECTED
OVER MOST OF THE MARINE AREA OVERNIGHT WITH SEAS 3-5 FT...HIGHEST
BEYOND 20 NM.

SUNDAY...A PINCHED PRESSURE GRADIENT BETWEEN DEVELOPING LOW PRESSURE
OFF THE GA COAST NEAR THE GULF STREAM AND A STRONG INLAND WEDGE OF
HIGH PRESSURE WILL PERSIST. THIS WILL RESULT IN NORTH/NE WINDS OF AT
LEAST 15-20 KT...WITH GUSTS AT TIMES TO NEAR 25 KT. IF THE GUSTS
BECOME FREQUENT ENOUGH WE/D NEED A SMALL CRAFT ADVISORY...WHICH
WE/LL DEFER TO FUTURE SHIFTS TO SEE IF WE INDEED SHOULD HOIST THE
ADVISORY HEADLINE. THE FETCH IS FAVORABLE ENOUGH FOR SEAS TO BE AS
HIGH AS 3-5 FT...GREATEST OVER AMZ374 AND THE EASTERNMOST PARTS OF
AMZ350.

SUNDAY NIGHT AND MONDAY...THE ATLANTIC WAVE DEEPENS SOME AS IT LIFTS
NE ALONG THE GULF STREAM...WHILE THE INLAND WEDGE HOLDS FIRM. THE
GRADIENT THOUGH DOES SLACKEN SOME OF THE LOW SHIFTS NORTH OF THE
LOCAL WATERS...AND WINDS AND SEAS WILL BE LESS AND BELOW ANY
ADVISORY CRITERIA.

MONDAY NIGHT AND TUESDAY...THE INLAND WEDGE IS STILL IN PLACE DURING
MUCH OF THE PERIOD...BUT IT DOES ATTEMPT TO ERODE BY TUESDAY NIGHT
AS THE COASTAL WARM FRONT STARTS TO LIFT NORTH/NW. UNTIL THIS
TRANSITION THOUGH OUR WINDS WILL STRUGGLE TO VEER AROUND...AS SPEEDS
HOLD NEAR OR BELOW 15 KT AND SEAS ARE LIMITED TO 3 OR 4 FT.

TUESDAY NIGHT AND WEDNESDAY...FINALLY THE COASTAL WARM FRONT WILL
SHIFT NORTH OF THE LOCAL WATERS TUESDAY NIGHT AS A STRONG COLD FRONT
MOVES THROUGH WEDNESDAY. WARM ADVECTION AND THE RESULTING
MARINE-LAYERING EFFECTS WILL LIMIT THE STRENGTH OF WINDS AHEAD OF
THE FRONT...BUT SMALL CRAFT ADVISORIES ARE CERTAINLY POSSIBLE.
BEHIND THE FRONT THE COMBINATION OF COLD ADVECTION AND STRONG
ISALLOBARIC PRESSURE RISES MAY SUPPORT GALES...OR AT THE LEAST SMALL
CRAFT ADVISORIES. MARINERS ARE ALSO ADVISED THAT SOME STRONGER
T-STORMS ARE POSSIBLE IN ADVANCE OF THE COLD FRONT...CAPABLE OF
PRODUCING GUSTY WINDS AND LIGHTNING STRIKES.

THURSDAY...CONDITIONS WILL IMPROVE OVER ALL WATERS AS HIGH PRESSURE
BECOMES CENTERED JUST SOUTH OF THE AREA. WINDS/SEAS SHOULD
EVENTUALLY LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL MARINE
ZONES AS COLD ADVECTION WANES AND THE GRADIENT RELAXES.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
INTO TUESDAY. ACTUAL SEA FOG MAY HAVE A WINDOW TO DEVELOP AS
SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE TUESDAY INTO TUESDAY NIGHT
PRIOR TO WINDS INCREASING ENOUGH TO SCOUR IT OUT WEDNESDAY. NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...GIVEN
THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AN INCREASING
RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY AROUND THE TIME
OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE FURTHER EXACERBATED
DUE TO STEADY RAINS PRIOR TO AND DURING THE HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...JRL/SPR
SHORT TERM...33
LONG TERM...DPB
AVIATION...33/JRL/SPR
MARINE...33/JRL/SPR
TIDES/COASTAL FLOODING...33








000
FXUS62 KCHS 202054
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
354 PM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH LATE TUESDAY
NIGHT...THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE
WILL THEN SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK...WITH A COLD
FRONT EXPECTED NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE PRIMARY UPPER VORT CAN BE SEEN ON WATER VAPOR IMAGERY SHIFTING
OFF THE SC COAST THIS AFTERNOON WITH SOME DRIER MID AND UPPER
LEVEL AIR MOVING INTO THE SOUTHEAST. THE RAIN TAPERED OFF OVER
MOST AREAS EARLIER THIS AFTERNOON WITH ONLY RESIDUAL PRECIP OVER
THE SC COASTAL WATERS. HOWEVER...MORE RECENTLY WE HAVE BEGUN TO
SEE SOME RADAR RETURNS ACROSS SOUTHERN GA MOVING NORTHEAST TOWARD
OUR FAR SW ZONES. THE 18Z NAM IS PICKING UP ON A WEAK 700 MB
DISTURBANCE LIFTING OUT OF THE CENTRAL GULF COAST REGION...PROGGED
TO LIFT THROUGH THE FORECAST AREA THROUGH THE OVERNIGHT HOURS. A
STRONGER MID-LEVEL SHORTWAVE WILL APPROACH FROM THE SW LATE
TONIGHT. ALTHOUGH FORCING AND MOISTURE WILL REMAIN LIMITED THROUGH
EARLY SUNDAY MORNING...WE MAINTAINED 20-40 POPS OVER MUCH OF THE
AREA.

THE HIGH PRESSURE WEDGE WILL BECOME FURTHER ENTRENCHED TONIGHT AS
THE SURFACE LOW STRENGTHENS OFF THE SC COAST. ABUNDANT BOUNDARY
LAYER MOISTURE WILL SUPPORT LOW OVERCAST SKIES...WITH THE
POTENTIAL FOR SOME BUILD-DOWN FOG. GEOSTROPHIC FLOW EXPECTED TO BE
GREATER THAN 15 KT OVERNIGHT WHICH MAY PRECLUDE A DENSE FOG EVENT.
ADDITIONALLY...NONE OF THE MODEL GUIDANCE IS CURRENTLY INDICATING
DENSE FOG POTENTIAL. WE MAINTAINED PATCHY FOG IN THE FORECAST
AFTER MIDNIGHT WITH CLOUDY SKIES. WEAK COLD ADVECTION WILL RESULT
IN LOW TEMPS IN THE LOWER TO MIDDLE 40S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...A WEAK SOUTHERN STREAM MID LEVEL PERTURBATION MOVING
THROUGH THE LOWER MS VALLEY FROM TONIGHT WILL CROSS THE AREA DURING
THE MORNING HOURS AND REINFORCES THE PRE-EXISTING STATIONARY FRONT
OVER THE ATLANTIC TO THE EAST/SE OF THE GULF STREAM. IT ALSO KEEPS
THE INLAND COOL HIGH PRESSURE WEDGE ANCHORED IN PLACE AS IT EXTENDS
SOUTH OF THE FORECAST AREA. THE IMPULSE ALOFT ALSO TRIGGERS WEAK
CYCLOGENESIS OFF THE SE COAST SOME 250 NM EAST OF SAVANNAH AS IT
MOVES LITTLE THROUGHOUT THE DAY. ISENTROPIC ASCENT WILL AGAIN BE THE
MAIN FACTOR FOR GENERATING RAINFALL...AS IT INCREASES IN MAGNITUDE
DURING THE AFTERNOON AND EVENING HOURS...AND POPS ACCORDINGLY WILL
BE ON THE INCREASE AS WELL DURING THE SECOND HALF OF THE DAY. WE/LL
START THE PERIOD WITH A LITTLE LIGHT RAIN...DRIZZLE AND/OR FOG
BEFORE POPS CLIMB INTO THE 30-50 PERCENTILE IN THE AFTERNOON.
GREATEST PROBABILITIES WILL BE OVER SE GA AND ESPECIALLY SOUTH OF
I-16 DURING THAT TIME. OVERCAST SKIES AND A CONTINUED FEED OF AIR
FROM THE NORTH/NE WITHIN THE LOW LEVEL WEDGE WILL KEEP TEMPS DOWN
MAINLY INTO THE 50S FOR MAX TEMPS.

SUNDAY NIGHT INTO MONDAY...ANOTHER AND SLIGHTLY STRONGER SHORT WAVE
ARRIVES FROM THE GULF OF MEXICO AND FORCES THE ATLANTIC WAVE TO
DEEPEN A FEW MILLIBARS AS IT LIFTS NE ROUGHLY ALONG THE GULF STREAM
TO A POSITION OFF CAPE HATTERAS BY 00Z TUESDAY. THIS PATTERN
REINFORCES THE WEDGE INLAND...WHICH IN TURN ALLOWS FOR A FURTHER
INCREASE IN ISENTROPIC ASCENT. THAT ALONG WITH FORCING FROM THE
UPPER JET OVER THE SE CORNER OF THE COUNTRY AND CONVERGENCE
ASSOCIATED WITH THE NEARBY ATLANTIC LOW WILL CAUSE COVERAGE OF RAIN
TO EXPAND INTO AT LEAST THE 70-80 PERCENT RANGE SUNDAY
NIGHT...BEFORE COVERAGE DIMINISHES FROM WEST TO EST ON MONDAY AS THE
SURFACE LOW PULLS AWAY. PWATS OF 1.3 TO 1.4 INCHES AND THE FLOW
ALOFT OPENING MORE OUT OF THE GULF OF MEXICO SUPPORTS AT LEAST 1/4
TO 1/2 INCH AMOUNTS OF RAIN. IN ADDITION...STEEPER MID LEVEL LAPSE
RATES AND SHOWALTER INDICES DROPPING TO NEAR ZERO COULD SUPPORT A
LITTLE ELEVATED CONVECTION. LOW STRATUS DECKS WILL ALSO SUPPORT SOME
REDUCTION IN SURFACE VISIBILITIES SUNDAY NIGHT INTO MONDAY MORNING
AND WE HAVE ADDED PATCHY FOG TO THE FORECAST. THERE IS ONLY A SMALL
5-10 DEGREE TEMP SWING FROM DAYTIME HIGHS SUNDAY TO NIGHTTIME LOWS
SUNDAY NIGHT. THEN A FAIRLY LARGE NORTH/NW TO SOUTH/SE TEMP GRADIENT
MONDAY WITH HIGHS NEAR OR SLIGHTLY BELOW NORMAL.

MONDAY NIGHT AND TUESDAY...YET ANOTHER QUICK MOVING SOUTHERN STREAM
SHORT WAVE ARRIVES LATE MONDAY NIGHT AND TUESDAY FROM THE GULF OF
MEXICO. FURTHER UPSTREAM A MORE PRONOUNCED SHORT WAVE STARTS TO DIG
THROUGH THE CENTRAL STATES...WHICH IN TURN AMPLIFIES THE LARGE SCALE
PATTERN ACROSS THE CONUS. THIS BACKS OUR FLOW ALOFT FURTHER TO THE
SW AND OPENS THE DOOR FOR A FEED OF EVEN DEEPER AND TROPICAL-LIKE
MOISTURE TO MOVE IN. PWATS CLIMB TO NEAR 2 STANDARD DEVIATIONS ABOVE
NORMAL...AROUND 1.6 TO 1.7 INCHES SO YET ANOTHER ROUND OF RAINFALL
WILL OCCUR. POPS WILL BE IN THE CHANCE TO LIKELY RANGE MONDAY NIGHT
THEN SHOULD PEAK IN THE CATEGORICAL RANGE TUESDAY. ADDITIONAL QPF
WILL BE AT LEAST 1/2 TO 3/4 INCHES...WITH POTENTIAL HIGHER AMOUNTS
IN THIS PATTERN. THE SHORT WAVE IN THE PLAINS WILL ALSO TRIGGER
CYCLOGENESIS NEAR THE ARKLATEX REGION BY TUESDAY...WHICH IN TURN
ATTEMPTS TO LIFT OUR COASTAL WARM FRONT NORTHWARD. NOT SURE HOW THIS
PROGRESSION WILL ACTUAL PAN OUT GIVEN THAT THE INLAND WEDGE WILL BE
RELUCTANT TO GIVE UP ITS HOLD. THIS WILL ALLOW FOR WARM ADVECTION TO
BOOST TEMPS AT LEAST INTO THE LOWER OR MIDDLE 60S...PERHAPS EVEN
HIGHER NEAR THE ALTAMAHA. THIS IN TURN CREATES SOME SURFACE BASED
INSTABILITY ON THE ORDER OF 500-800 J/KG IN SYNC WITH STEEP MID
LEVEL LAPSE RATES OVER OUR COASTAL ZONES AND SOUTH OF I-16. IT/S IN
THESE AREAS WHERE WE HAVE ISOLATED T-STORMS MENTIONED IN THE LATEST
FORECAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CEILINGS WILL CONTINUE TO BOUNCE ALL OVER THE PLACE THIS AFTERNOON
AS POCKETS OF DRY AIR INTERACT WITH AN OTHERWISE DEEP MOIST LAYER
IN PLACE. SPORADIC IFR CONDITIONS THROUGH MID AFTERNOON WILL
RETURN TO VFR FOR MUCH OF THE EVENING AS DRIER MID AND HIGH LEVEL
AIR SHIFTS IN. OVERNIGHT...THE MODELS ARE SPLIT REGARDING THE
POTENTIAL FOR IFR CEILINGS AND BUILD-DOWN FOG. MODEL SOUNDINGS AND
SEASONAL CLIMATOLOGY BOTH SUPPORT PREVAILING IFR CEILINGS AND
3-4SM VSBYS FROM LATE THIS EVENING THROUGH DAYBREAK SUNDAY. AT
LEAST MVFR CEILINGS ARE LIKELY TO PERSIST THROUGH MUCH OF THE DAY
SUNDAY. RAIN WILL OVERSPREAD THE AREA FROM THE SOUTH DURING THE
DAY SUNDAY BUT THE BEST CHANCE WILL BE AFTER 18Z SO WE DID NOT
INCORPORATE INTO THE CURRENT TAF SET.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH EARLY TUESDAY
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON AS A STRONG COLD FRONT APPROACHES FROM THE
WEST WITH SHOWERS AND POSSIBLY THUNDERSTORMS. WINDY CONDITIONS
SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
THE TIGHT NORTHEAST GRADIENT WILL PERSIST THROUGH TONIGHT AS HIGH
PRESSURE CONTINUES TO WEDGE DOWN THE EASTERN SEABOARD AND LOW
PRESSURE SPINS OFF THE SC COAST. A STEADY 15-20 KT WIND EXPECTED
OVER MOST OF THE MARINE AREA OVERNIGHT WITH SEAS BUILDING TO 5 FT
OVER OUTER PORTIONS BY LATE TONIGHT.

SUNDAY...A PINCHED PRESSURE GRADIENT BETWEEN DEVELOPING LOW PRESSURE
OFF THE GA COAST NEAR THE GULF STREAM AND A STRONG INLAND WEDGE OF
HIGH PRESSURE WILL PERSIST. THIS WILL RESULT IN NORTH/NE WINDS OF AT
LEAST 15-20 KT...WITH GUSTS AT TIMES TO NEAR 25 KT. IF THE GUSTS
BECOME FREQUENT ENOUGH WE/D NEED A SMALL CRAFT ADVISORY...WHICH
WE/LL DEFER TO FUTURE SHIFTS TO SEE IF WE INDEED SHOULD HOIST THE
ADVISORY HEADLINE. THE FETCH IS FAVORABLE ENOUGH FOR SEAS TO BE AS
HIGH AS 3-5 FT...GREATEST OVER AMZ374 AND THE EASTERNMOST PARTS OF
AMZ350.

SUNDAY NIGHT AND MONDAY...THE ATLANTIC WAVE DEEPENS SOME AS IT LIFTS
NE ALONG THE GULF STREAM...WHILE THE INLAND WEDGE HOLDS FIRM. THE
GRADIENT THOUGH DOES SLACKEN SOME OF THE LOW SHIFTS NORTH OF THE
LOCAL WATERS...AND WINDS AND SEAS WILL BE LESS AND BELOW ANY
ADVISORY CRITERIA.

MONDAY NIGHT AND TUESDAY...THE INLAND WEDGE IS STILL IN PLACE DURING
MUCH OF THE PERIOD...BUT IT DOES ATTEMPT TO ERODE BY TUESDAY NIGHT
AS THE COASTAL WARM FRONT STARTS TO LIFT NORTH/NW. UNTIL THIS
TRANSITION THOUGH OUR WINDS WILL STRUGGLE TO VEER AROUND...AS SPEEDS
HOLD NEAR OR BELOW 15 KT AND SEAS ARE LIMITED TO 3 OR 4 FT.

TUESDAY NIGHT AND WEDNESDAY...FINALLY THE COASTAL WARM FRONT WILL
SHIFT NORTH OF THE LOCAL WATERS TUESDAY NIGHT AS A STRONG COLD FRONT
MOVES THROUGH WEDNESDAY. WARM ADVECTION AND THE RESULTING
MARINE-LAYERING EFFECTS WILL LIMIT THE STRENGTH OF WINDS AHEAD OF
THE FRONT...BUT SMALL CRAFT ADVISORIES ARE CERTAINLY POSSIBLE.
BEHIND THE FRONT THE COMBINATION OF COLD ADVECTION AND STRONG
ISALLOBARIC PRESSURE RISES MAY SUPPORT GALES...OR AT THE LEAST SMALL
CRAFT ADVISORIES. MARINERS ARE ALSO ADVISED THAT SOME STRONGER
T-STORMS ARE POSSIBLE IN ADVANCE OF THE COLD FRONT...CAPABLE OF
PRODUCING GUSTY WINDS AND LIGHTNING STRIKES.

THURSDAY...CONDITIONS WILL IMPROVE OVER ALL WATERS AS HIGH PRESSURE
BECOMES CENTERED JUST SOUTH OF THE AREA. WINDS/SEAS SHOULD
EVENTUALLY LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL MARINE
ZONES AS COLD ADVECTION WANES AND THE GRADIENT RELAXES.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
INTO TUESDAY. ACTUAL SEA FOG MAY HAVE A WINDOW TO DEVELOP AS
SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE TUESDAY INTO TUESDAY NIGHT
PRIOR TO WINDS INCREASING ENOUGH TO SCOUR IT OUT WEDNESDAY. NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...GIVEN
THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AN INCREASING
RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY AROUND THE TIME
OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE FURTHER EXACERBATED
DUE TO STEADY RAINS PRIOR TO AND DURING THE HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...JRL
SHORT TERM...33
LONG TERM...DPB
AVIATION...33/JRL
MARINE...33/JRL
TIDES/COASTAL FLOODING...33







000
FXUS62 KCHS 202054
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
354 PM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH LATE TUESDAY
NIGHT...THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE
WILL THEN SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK...WITH A COLD
FRONT EXPECTED NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE PRIMARY UPPER VORT CAN BE SEEN ON WATER VAPOR IMAGERY SHIFTING
OFF THE SC COAST THIS AFTERNOON WITH SOME DRIER MID AND UPPER
LEVEL AIR MOVING INTO THE SOUTHEAST. THE RAIN TAPERED OFF OVER
MOST AREAS EARLIER THIS AFTERNOON WITH ONLY RESIDUAL PRECIP OVER
THE SC COASTAL WATERS. HOWEVER...MORE RECENTLY WE HAVE BEGUN TO
SEE SOME RADAR RETURNS ACROSS SOUTHERN GA MOVING NORTHEAST TOWARD
OUR FAR SW ZONES. THE 18Z NAM IS PICKING UP ON A WEAK 700 MB
DISTURBANCE LIFTING OUT OF THE CENTRAL GULF COAST REGION...PROGGED
TO LIFT THROUGH THE FORECAST AREA THROUGH THE OVERNIGHT HOURS. A
STRONGER MID-LEVEL SHORTWAVE WILL APPROACH FROM THE SW LATE
TONIGHT. ALTHOUGH FORCING AND MOISTURE WILL REMAIN LIMITED THROUGH
EARLY SUNDAY MORNING...WE MAINTAINED 20-40 POPS OVER MUCH OF THE
AREA.

THE HIGH PRESSURE WEDGE WILL BECOME FURTHER ENTRENCHED TONIGHT AS
THE SURFACE LOW STRENGTHENS OFF THE SC COAST. ABUNDANT BOUNDARY
LAYER MOISTURE WILL SUPPORT LOW OVERCAST SKIES...WITH THE
POTENTIAL FOR SOME BUILD-DOWN FOG. GEOSTROPHIC FLOW EXPECTED TO BE
GREATER THAN 15 KT OVERNIGHT WHICH MAY PRECLUDE A DENSE FOG EVENT.
ADDITIONALLY...NONE OF THE MODEL GUIDANCE IS CURRENTLY INDICATING
DENSE FOG POTENTIAL. WE MAINTAINED PATCHY FOG IN THE FORECAST
AFTER MIDNIGHT WITH CLOUDY SKIES. WEAK COLD ADVECTION WILL RESULT
IN LOW TEMPS IN THE LOWER TO MIDDLE 40S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...A WEAK SOUTHERN STREAM MID LEVEL PERTURBATION MOVING
THROUGH THE LOWER MS VALLEY FROM TONIGHT WILL CROSS THE AREA DURING
THE MORNING HOURS AND REINFORCES THE PRE-EXISTING STATIONARY FRONT
OVER THE ATLANTIC TO THE EAST/SE OF THE GULF STREAM. IT ALSO KEEPS
THE INLAND COOL HIGH PRESSURE WEDGE ANCHORED IN PLACE AS IT EXTENDS
SOUTH OF THE FORECAST AREA. THE IMPULSE ALOFT ALSO TRIGGERS WEAK
CYCLOGENESIS OFF THE SE COAST SOME 250 NM EAST OF SAVANNAH AS IT
MOVES LITTLE THROUGHOUT THE DAY. ISENTROPIC ASCENT WILL AGAIN BE THE
MAIN FACTOR FOR GENERATING RAINFALL...AS IT INCREASES IN MAGNITUDE
DURING THE AFTERNOON AND EVENING HOURS...AND POPS ACCORDINGLY WILL
BE ON THE INCREASE AS WELL DURING THE SECOND HALF OF THE DAY. WE/LL
START THE PERIOD WITH A LITTLE LIGHT RAIN...DRIZZLE AND/OR FOG
BEFORE POPS CLIMB INTO THE 30-50 PERCENTILE IN THE AFTERNOON.
GREATEST PROBABILITIES WILL BE OVER SE GA AND ESPECIALLY SOUTH OF
I-16 DURING THAT TIME. OVERCAST SKIES AND A CONTINUED FEED OF AIR
FROM THE NORTH/NE WITHIN THE LOW LEVEL WEDGE WILL KEEP TEMPS DOWN
MAINLY INTO THE 50S FOR MAX TEMPS.

SUNDAY NIGHT INTO MONDAY...ANOTHER AND SLIGHTLY STRONGER SHORT WAVE
ARRIVES FROM THE GULF OF MEXICO AND FORCES THE ATLANTIC WAVE TO
DEEPEN A FEW MILLIBARS AS IT LIFTS NE ROUGHLY ALONG THE GULF STREAM
TO A POSITION OFF CAPE HATTERAS BY 00Z TUESDAY. THIS PATTERN
REINFORCES THE WEDGE INLAND...WHICH IN TURN ALLOWS FOR A FURTHER
INCREASE IN ISENTROPIC ASCENT. THAT ALONG WITH FORCING FROM THE
UPPER JET OVER THE SE CORNER OF THE COUNTRY AND CONVERGENCE
ASSOCIATED WITH THE NEARBY ATLANTIC LOW WILL CAUSE COVERAGE OF RAIN
TO EXPAND INTO AT LEAST THE 70-80 PERCENT RANGE SUNDAY
NIGHT...BEFORE COVERAGE DIMINISHES FROM WEST TO EST ON MONDAY AS THE
SURFACE LOW PULLS AWAY. PWATS OF 1.3 TO 1.4 INCHES AND THE FLOW
ALOFT OPENING MORE OUT OF THE GULF OF MEXICO SUPPORTS AT LEAST 1/4
TO 1/2 INCH AMOUNTS OF RAIN. IN ADDITION...STEEPER MID LEVEL LAPSE
RATES AND SHOWALTER INDICES DROPPING TO NEAR ZERO COULD SUPPORT A
LITTLE ELEVATED CONVECTION. LOW STRATUS DECKS WILL ALSO SUPPORT SOME
REDUCTION IN SURFACE VISIBILITIES SUNDAY NIGHT INTO MONDAY MORNING
AND WE HAVE ADDED PATCHY FOG TO THE FORECAST. THERE IS ONLY A SMALL
5-10 DEGREE TEMP SWING FROM DAYTIME HIGHS SUNDAY TO NIGHTTIME LOWS
SUNDAY NIGHT. THEN A FAIRLY LARGE NORTH/NW TO SOUTH/SE TEMP GRADIENT
MONDAY WITH HIGHS NEAR OR SLIGHTLY BELOW NORMAL.

MONDAY NIGHT AND TUESDAY...YET ANOTHER QUICK MOVING SOUTHERN STREAM
SHORT WAVE ARRIVES LATE MONDAY NIGHT AND TUESDAY FROM THE GULF OF
MEXICO. FURTHER UPSTREAM A MORE PRONOUNCED SHORT WAVE STARTS TO DIG
THROUGH THE CENTRAL STATES...WHICH IN TURN AMPLIFIES THE LARGE SCALE
PATTERN ACROSS THE CONUS. THIS BACKS OUR FLOW ALOFT FURTHER TO THE
SW AND OPENS THE DOOR FOR A FEED OF EVEN DEEPER AND TROPICAL-LIKE
MOISTURE TO MOVE IN. PWATS CLIMB TO NEAR 2 STANDARD DEVIATIONS ABOVE
NORMAL...AROUND 1.6 TO 1.7 INCHES SO YET ANOTHER ROUND OF RAINFALL
WILL OCCUR. POPS WILL BE IN THE CHANCE TO LIKELY RANGE MONDAY NIGHT
THEN SHOULD PEAK IN THE CATEGORICAL RANGE TUESDAY. ADDITIONAL QPF
WILL BE AT LEAST 1/2 TO 3/4 INCHES...WITH POTENTIAL HIGHER AMOUNTS
IN THIS PATTERN. THE SHORT WAVE IN THE PLAINS WILL ALSO TRIGGER
CYCLOGENESIS NEAR THE ARKLATEX REGION BY TUESDAY...WHICH IN TURN
ATTEMPTS TO LIFT OUR COASTAL WARM FRONT NORTHWARD. NOT SURE HOW THIS
PROGRESSION WILL ACTUAL PAN OUT GIVEN THAT THE INLAND WEDGE WILL BE
RELUCTANT TO GIVE UP ITS HOLD. THIS WILL ALLOW FOR WARM ADVECTION TO
BOOST TEMPS AT LEAST INTO THE LOWER OR MIDDLE 60S...PERHAPS EVEN
HIGHER NEAR THE ALTAMAHA. THIS IN TURN CREATES SOME SURFACE BASED
INSTABILITY ON THE ORDER OF 500-800 J/KG IN SYNC WITH STEEP MID
LEVEL LAPSE RATES OVER OUR COASTAL ZONES AND SOUTH OF I-16. IT/S IN
THESE AREAS WHERE WE HAVE ISOLATED T-STORMS MENTIONED IN THE LATEST
FORECAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CEILINGS WILL CONTINUE TO BOUNCE ALL OVER THE PLACE THIS AFTERNOON
AS POCKETS OF DRY AIR INTERACT WITH AN OTHERWISE DEEP MOIST LAYER
IN PLACE. SPORADIC IFR CONDITIONS THROUGH MID AFTERNOON WILL
RETURN TO VFR FOR MUCH OF THE EVENING AS DRIER MID AND HIGH LEVEL
AIR SHIFTS IN. OVERNIGHT...THE MODELS ARE SPLIT REGARDING THE
POTENTIAL FOR IFR CEILINGS AND BUILD-DOWN FOG. MODEL SOUNDINGS AND
SEASONAL CLIMATOLOGY BOTH SUPPORT PREVAILING IFR CEILINGS AND
3-4SM VSBYS FROM LATE THIS EVENING THROUGH DAYBREAK SUNDAY. AT
LEAST MVFR CEILINGS ARE LIKELY TO PERSIST THROUGH MUCH OF THE DAY
SUNDAY. RAIN WILL OVERSPREAD THE AREA FROM THE SOUTH DURING THE
DAY SUNDAY BUT THE BEST CHANCE WILL BE AFTER 18Z SO WE DID NOT
INCORPORATE INTO THE CURRENT TAF SET.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH EARLY TUESDAY
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON AS A STRONG COLD FRONT APPROACHES FROM THE
WEST WITH SHOWERS AND POSSIBLY THUNDERSTORMS. WINDY CONDITIONS
SHOULD ALSO OCCUR NEAR THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
THE TIGHT NORTHEAST GRADIENT WILL PERSIST THROUGH TONIGHT AS HIGH
PRESSURE CONTINUES TO WEDGE DOWN THE EASTERN SEABOARD AND LOW
PRESSURE SPINS OFF THE SC COAST. A STEADY 15-20 KT WIND EXPECTED
OVER MOST OF THE MARINE AREA OVERNIGHT WITH SEAS BUILDING TO 5 FT
OVER OUTER PORTIONS BY LATE TONIGHT.

SUNDAY...A PINCHED PRESSURE GRADIENT BETWEEN DEVELOPING LOW PRESSURE
OFF THE GA COAST NEAR THE GULF STREAM AND A STRONG INLAND WEDGE OF
HIGH PRESSURE WILL PERSIST. THIS WILL RESULT IN NORTH/NE WINDS OF AT
LEAST 15-20 KT...WITH GUSTS AT TIMES TO NEAR 25 KT. IF THE GUSTS
BECOME FREQUENT ENOUGH WE/D NEED A SMALL CRAFT ADVISORY...WHICH
WE/LL DEFER TO FUTURE SHIFTS TO SEE IF WE INDEED SHOULD HOIST THE
ADVISORY HEADLINE. THE FETCH IS FAVORABLE ENOUGH FOR SEAS TO BE AS
HIGH AS 3-5 FT...GREATEST OVER AMZ374 AND THE EASTERNMOST PARTS OF
AMZ350.

SUNDAY NIGHT AND MONDAY...THE ATLANTIC WAVE DEEPENS SOME AS IT LIFTS
NE ALONG THE GULF STREAM...WHILE THE INLAND WEDGE HOLDS FIRM. THE
GRADIENT THOUGH DOES SLACKEN SOME OF THE LOW SHIFTS NORTH OF THE
LOCAL WATERS...AND WINDS AND SEAS WILL BE LESS AND BELOW ANY
ADVISORY CRITERIA.

MONDAY NIGHT AND TUESDAY...THE INLAND WEDGE IS STILL IN PLACE DURING
MUCH OF THE PERIOD...BUT IT DOES ATTEMPT TO ERODE BY TUESDAY NIGHT
AS THE COASTAL WARM FRONT STARTS TO LIFT NORTH/NW. UNTIL THIS
TRANSITION THOUGH OUR WINDS WILL STRUGGLE TO VEER AROUND...AS SPEEDS
HOLD NEAR OR BELOW 15 KT AND SEAS ARE LIMITED TO 3 OR 4 FT.

TUESDAY NIGHT AND WEDNESDAY...FINALLY THE COASTAL WARM FRONT WILL
SHIFT NORTH OF THE LOCAL WATERS TUESDAY NIGHT AS A STRONG COLD FRONT
MOVES THROUGH WEDNESDAY. WARM ADVECTION AND THE RESULTING
MARINE-LAYERING EFFECTS WILL LIMIT THE STRENGTH OF WINDS AHEAD OF
THE FRONT...BUT SMALL CRAFT ADVISORIES ARE CERTAINLY POSSIBLE.
BEHIND THE FRONT THE COMBINATION OF COLD ADVECTION AND STRONG
ISALLOBARIC PRESSURE RISES MAY SUPPORT GALES...OR AT THE LEAST SMALL
CRAFT ADVISORIES. MARINERS ARE ALSO ADVISED THAT SOME STRONGER
T-STORMS ARE POSSIBLE IN ADVANCE OF THE COLD FRONT...CAPABLE OF
PRODUCING GUSTY WINDS AND LIGHTNING STRIKES.

THURSDAY...CONDITIONS WILL IMPROVE OVER ALL WATERS AS HIGH PRESSURE
BECOMES CENTERED JUST SOUTH OF THE AREA. WINDS/SEAS SHOULD
EVENTUALLY LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL MARINE
ZONES AS COLD ADVECTION WANES AND THE GRADIENT RELAXES.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
INTO TUESDAY. ACTUAL SEA FOG MAY HAVE A WINDOW TO DEVELOP AS
SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE TUESDAY INTO TUESDAY NIGHT
PRIOR TO WINDS INCREASING ENOUGH TO SCOUR IT OUT WEDNESDAY. NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...GIVEN
THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AN INCREASING
RISK FOR SHALLOW COASTAL FLOODING MONDAY AND TUESDAY AROUND THE TIME
OF THE MORNING HIGH TIDE. THIS SITUATION MIGHT BE FURTHER EXACERBATED
DUE TO STEADY RAINS PRIOR TO AND DURING THE HIGH TIDAL CYCLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...JRL
SHORT TERM...33
LONG TERM...DPB
AVIATION...33/JRL
MARINE...33/JRL
TIDES/COASTAL FLOODING...33








000
FXUS62 KCHS 201847
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
147 PM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH TUESDAY NIGHT...
THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE WILL THEN
SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL SHORTWAVE IS PROGRESSING INTO NORTH GA AND THE SC
UPSTATE LATE THIS MORNING. MEANWHILE THE SUBTROPICAL JET STREAM
HAS SHIFTED EVER SO SLIGHTLY NORTH...MOVING THE REGION OF DIVERGENCE
TO OUR NORTH. WATER VAPOR IMAGERY SHOWS A LARGE AREA OF MID AND
HIGH LEVEL DRY AIR THAT WILL PUSH INTO THE REGION LATER THIS
AFTERNOON BEHIND THE SHORTWAVE. AT THE SURFACE WE HAVE WEAK HIGH
PRESSURE WEDGING DOWN THE EASTERN SEABOARD AND A SURFACE LOW
DEVELOPING OFF THE COAST. WE EXPECT FAIRLY WIDESPREAD LIGHT RAIN
TO CONTINUE INTO EARLY THIS AFTERNOON...ESPECIALLY ACROSS THE
NORTHERN HALF OF THE AREA CLOSER TO THE UPPER FORCING. BY MID TO
LATE AFTERNOON...ONCE PVA ASSOCIATED WITH THE SHORTWAVE SHIFTS OFF
THE COAST AND SOME DRIER AIR SHIFTS IN ALOFT...THE RAIN SHOULD
QUICKLY TAPER OFF FROM WEST TO EAST. CURRENT POP SCHEME LOOKS VERY
GOOD. CLOUDY SKIES SHOULD CONTINUE TODAY. TEMPS WILL REMAIN FAIRLY
STEADY THROUGH EARLY TO MID AFTERNOON DUE TO WEAK LOW-LEVEL COLD
ADVECTION AND EVAPORATIONAL COOLING. LATE IN THE DAY WE COULD SEE
A BRIEF REBOUND IN TEMPERATURES ONCE THE RAIN ENDS...BUT HIGHS
WILL NOT MAKE IT OUT OF THE 50S.

TONIGHT WE LIKE THE SREF REPRESENTATION OF LOW CLOUDS EXPANDING
INLAND THIS EVENING WITH STRATUS PERHAPS BUILDING DOWN IN SOME
AREAS BUT CONFIDENCE ONLY ENOUGH TO ADD PATCHY FOG TO THE FORECAST
OVERNIGHT AS LOW CLOUDS REMAIN MORE CERTAIN AT THIS POINT. LACK OF
FORCING SUGGESTS ANY LIGHT RAINS AROUND TONIGHT WOULD BE PATCHY
WITH SOME DRIZZLE AROUND THE REGION. POPS ONLY IN THE SLIGHT
CHANCE WERE MAINTAINED AND LOWS IN THE 40S ACROSS THE BOARD.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE DAY SHOULD START OFF SOMEWHAT DRY...BEFORE A PLUME OF
MOISTURE ADVECTS NORTH AS AN AREA OF LOW PRESSURE OVER THE NORTHEAST
GULF OF MEXICO SLOWLY SHIFTS OVER THE SOUTHEASTERN UNITED STATES
SUNDAY NIGHT. HAVE THEREFORE KEPT A GENERAL TREND OF RAMPING UP POPS
FROM SOUTHEAST GEORGIA TO SOUTHEAST SOUTH CAROLINA...WITH POPS
APPROACHING 80-90 SUNDAY NIGHT. GREATEST CHANCES OF PRECIP STILL
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...GIVEN THE LATEST TRACK ALONG THE SOUTHEAST
COAST. OVERALL HIGH TEMPS WILL BE DEPENDENT ON THE LOW TRACK...BUT
SHOULD REACH THE MID/UPPER 50S OVER MOST LOCATIONS AWAY FROM THE
COAST. TEMPS COULD PEAK NEAR 60 ALONG COASTAL AREAS IN SOUTHEAST
GEORGIA. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 40S AWAY FROM
THE COAST...AND IN THE LOW 50S ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE DURING THE AFTERNOON...BUT ELEVATED
PRECIP CHANCES WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE
EVENING WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE HIGH
PRESSURE WEDGE INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER
50S INLAND TO LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH
CAROLINA COAST.

MONDAY NIGHT INTO TUESDAY...MODELS CONTINUE TO SUGGEST INCREASING
PRECIP CHANCES LATE MONDAY NIGHT INTO TUESDAY AS A COASTAL FRONT
LIFTS NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A
PERIOD OF WARMING SHOULD OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
STRONG COLD FRONT TO THE WEST...WITH HIGH TEMPS APPROACHING THE
MID/UPPER 60S TUESDAY AFTERNOON. DEEPENING MOISTURE CHARACTERIZED BY
PWATS BETWEEN 1.8-1.9 INCHES ALONG WITH THE WARMER TEMPS SHOULD BE
SUFFICIENT FOR A FEW THUNDERSTORMS DURING THE AFTERNOON. GREATEST
CHANCES SHOULD OCCUR OVER SOUTHEAST GEORGIA WHERE SBCAPES APPROACH
800 J/KG AND MID LVL LAPSE RATES ARE NEAR 7 C/KM.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
CEILINGS WILL CONTINUE TO BOUNCE ALL OVER THE PLACE THIS AFTERNOON
AS POCKETS OF DRY AIR INTERACT WITH AN OTHERWISE DEEP MOIST LAYER
IN PLACE. SPORADIC IFR CONDITIONS THROUGH MID AFTERNOON WILL
RETURN TO VFR FOR MUCH OF THE EVENING AS DRIER MID AND HIGH LEVEL
AIR SHIFTS IN. OVERNIGHT...THE MODELS ARE SPLIT REGARDING THE
POTENTIAL FOR IFR CEILINGS AND BUILD-DOWN FOG. MODEL SOUNDINGS AND
SEASONAL CLIMATOLOGY BOTH SUPPORT PREVAILING IFR CEILINGS AND
3-4SM VSBYS FROM LATE THIS EVENING THROUGH DAYBREAK SUNDAY. AT
LEAST MVFR CEILINGS ARE LIKELY TO PERSIST THROUGH MUCH OF THE DAY
SUNDAY. RAIN WILL OVERSPREAD THE AREA FROM THE SOUTH DURING THE
DAY SUNDAY BUT THE BEST CHANCE WILL BE AFTER 18Z SO WE DID NOT
INCORPORATE INTO THE CURRENT TAF SET.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
ARE LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH MONDAY NIGHT
WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW
PRESSURE LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL
FLIGHT RESTRICTIONS APPEAR LIKELY TUESDAY INTO WEDNESDAY AFTERNOON
AS A STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND
POSSIBLY THUNDERSTORMS. WINDY CONDITIONS SHOULD ALSO OCCUR NEAR
THE TIME OF FRONTAL PASSAGE ON WEDNESDAY.

&&

.MARINE...
PINCHED NORTHEAST GRADIENT ONGOING DUE TO INLAND SURFACE HIGH
PRESSURE AND LOW PRESSURE DEEPENING OFF OUR COAST. THE TIGHTEST
GRADIENT IS ACROSS THE CHARLESTON NEARSHORE WATERS BUT WILL RIPPLE
DOWN THE COAST THROUGH THIS EVENING. SEAS WILL GRADUALLY BUILD
THIS AFTERNOON BUT ALL AREAS WILL REMAIN BELOW ADVISORY CRITERIA.

SUNDAY THROUGH MONDAY NIGHT...CONDITIONS SHOULD REMAIN JUST BELOW
SMALL CRAFT ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE HOLDS INLAND
WHILE LOW PRESSURE SLOWLY DEVELOPS AND SHIFTS NORTHEAST ALONG THE
COAST. PERIODS OF RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS
THROUGH MONDAY NIGHT WHILE A COASTAL FRONT REMAINS ALONG THE COAST.
IN GENERAL...WINDS SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS UP TO
3-4 FT.

TUESDAY AND WEDNESDAY....CONDITIONS SHOULD BEGIN TO DETERIORATE AS A
COASTAL FRONT LIFTS NORTH WELL AHEAD OF A STRONG COLD FRONT THAT
EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WINDS ARE POSSIBLE AS THE COLD
FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY AFTERNOON AND NIGHT AS WINDS GUST TO 30-35 KT.
SEAS WILL ALSO BUILD UPWARDS TO 6-9 FT WEDNESDAY AFTERNOON INTO
EARLY WEDNESDAY NIGHT BEFORE IMPROVING LATE.

THURSDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS AS HIGH
PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
TONIGHT INTO MONDAY. SEA FOG COULD DEVELOP AS SLIGHTLY WARMER AIR
ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS WITHIN A SOUTH AND
SOUTHWEST FLOW LATE MONDAY INTO TUESDAY PRIOR TO WINDS INCREASING
ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...JRL
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...JRL
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 201541
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1041 AM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH TUESDAY NIGHT...
THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE WILL THEN
SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL SHORTWAVE IS PROGRESSING INTO NORTH GA AND THE SC
UPSTATE LATE THIS MORNING. MEANWHILE THE SUBTROPICAL JET STREAM
HAS SHIFTED EVER SO SLIGHTLY NORTH...MOVING THE REGION OF DIVERGENCE
TO OUR NORTH. WATER VAPOR IMAGERY SHOWS A LARGE AREA OF MID AND
HIGH LEVEL DRY AIR THAT WILL PUSH INTO THE REGION LATER THIS
AFTERNOON BEHIND THE SHORTWAVE. AT THE SURFACE WE HAVE WEAK HIGH
PRESSURE WEDGING DOWN THE EASTERN SEABOARD AND A SURFACE LOW
DEVELOPING OFF THE COAST. WE EXPECT FAIRLY WIDESPREAD LIGHT RAIN
TO CONTINUE INTO EARLY THIS AFTERNOON...ESPECIALLY ACROSS THE
NORTHERN HALF OF THE AREA CLOSER TO THE UPPER FORCING. BY MID TO
LATE AFTERNOON...ONCE PVA ASSOCIATED WITH THE SHORTWAVE SHIFTS OFF
THE COAST AND SOME DRIER AIR SHIFTS IN ALOFT...THE RAIN SHOULD
QUICKLY TAPER OFF FROM WEST TO EAST. CURRENT POP SCHEME LOOKS VERY
GOOD. CLOUDY SKIES SHOULD CONTINUE TODAY. TEMPS WILL REMAIN FAIRLY
STEADY THROUGH EARLY TO MID AFTERNOON DUE TO WEAK LOW-LEVEL COLD
ADVECTION AND EVAPORATIONAL COOLING. LATE IN THE DAY WE COULD SEE
A BRIEF REBOUND IN TEMPERATURES ONCE THE RAIN ENDS...BUT HIGHS
WILL NOT MAKE IT OUT OF THE 50S.

TONIGHT WE LIKE THE SREF REPRESENTATION OF LOW CLOUDS EXPANDING
INLAND THIS EVENING WITH STRATUS PERHAPS BUILDING DOWN IN SOME
AREAS BUT CONFIDENCE ONLY ENOUGH TO ADD PATCHY FOG TO THE FORECAST
OVERNIGHT AS LOW CLOUDS REMAIN MORE CERTAIN AT THIS POINT. LACK OF
FORCING SUGGESTS ANY LIGHT RAINS AROUND TONIGHT WOULD BE PATCHY
WITH SOME DRIZZLE AROUND THE REGION. POPS ONLY IN THE SLIGHT
CHANCE WERE MAINTAINED AND LOWS IN THE 40S ACROSS THE BOARD.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE DAY SHOULD START OFF SOMEWHAT DRY...BEFORE A PLUME OF
MOISTURE ADVECTS NORTH AS AN AREA OF LOW PRESSURE OVER THE NORTHEAST
GULF OF MEXICO SLOWLY SHIFTS OVER THE SOUTHEASTERN UNITED STATES
SUNDAY NIGHT. HAVE THEREFORE KEPT A GENERAL TREND OF RAMPING UP POPS
FROM SOUTHEAST GEORGIA TO SOUTHEAST SOUTH CAROLINA...WITH POPS
APPROACHING 80-90 SUNDAY NIGHT. GREATEST CHANCES OF PRECIP STILL
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...GIVEN THE LATEST TRACK ALONG THE SOUTHEAST
COAST. OVERALL HIGH TEMPS WILL BE DEPENDENT ON THE LOW TRACK...BUT
SHOULD REACH THE MID/UPPER 50S OVER MOST LOCATIONS AWAY FROM THE
COAST. TEMPS COULD PEAK NEAR 60 ALONG COASTAL AREAS IN SOUTHEAST
GEORGIA. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 40S AWAY FROM
THE COAST...AND IN THE LOW 50S ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE DURING THE AFTERNOON...BUT ELEVATED
PRECIP CHANCES WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE
EVENING WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE HIGH
PRESSURE WEDGE INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER
50S INLAND TO LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH
CAROLINA COAST.

MONDAY NIGHT INTO TUESDAY...MODELS CONTINUE TO SUGGEST INCREASING
PRECIP CHANCES LATE MONDAY NIGHT INTO TUESDAY AS A COASTAL FRONT
LIFTS NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A
PERIOD OF WARMING SHOULD OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
STRONG COLD FRONT TO THE WEST...WITH HIGH TEMPS APPROACHING THE
MID/UPPER 60S TUESDAY AFTERNOON. DEEPENING MOISTURE CHARACTERIZED BY
PWATS BETWEEN 1.8-1.9 INCHES ALONG WITH THE WARMER TEMPS SHOULD BE
SUFFICIENT FOR A FEW THUNDERSTORMS DURING THE AFTERNOON. GREATEST
CHANCES SHOULD OCCUR OVER SOUTHEAST GEORGIA WHERE SBCAPES APPROACH
800 J/KG AND MID LVL LAPSE RATES ARE NEAR 7 C/KM.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
GRADUALLY DETERIORATING CIGS ANTICIPATED THIS MORNING PER LATEST
FORECAST SOUNDINGS AT KCHS/KSAV. AS MOISTURE DEEPENS WITH THE
UPPER DISTURBANCE APPROACHING AND SOME INFLUX OF ATLC MOISTURE...
CIGS SHOULD FALL TO MVFR LEVELS BY MIDDAY WITH A CHANCE OF IFR CIGS
THIS AFTERNOON AT EITHER TERMINAL. CONFIDENCE IN LOWER CIGS INCREASES
TONIGHT AS A WEDGE INVERSION STRENGTHENS AND STRATUS EXPANDS AND
LOWERS. FORECAST 06Z SOUNDINGS NOT CLEAR CUT HOWEVER AND VARY GREATER
FROM GFS SOUNDINGS AT THIS TIME. WE TRENDED INTO IFR RANGE AFTER
MIDNIGHT ON THIS TAF CYCLE AND INTRODUCED MVFR VSBYS IN FOG. RAIN
SHOULD TAPER OFF AT KCHS LATE TODAY AND BRUSH KSAV THROUGH EARLY
TO MID AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH MONDAY NIGHT WHILE
A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY INTO WEDNESDAY AFTERNOON AS A
STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND POSSIBLY
THUNDERSTORMS. WINDY CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF
FROPA ON WEDNESDAY.

&&

.MARINE...
A WAVE OF LOW PRESSURE DEVELOPING ALONG THE WEST WALL OF THE GULF
STREAM TODAY AND DRIFTING ENE THROUGH TONIGHT. HIGH PRES WILL WEDGE
IN FROM THE NORTH IN THE WAKE OF THIS LOW AND BEGIN TO PINCH THE
PRES GRADIENT OFF THE COAST. A 4-6 MILLIBAR PRES GRADIENT FROM THE
GULF STREAM TO THE LAND WILL LIKELY ANCHOR A NE FLOW IN THE 15 TO
20 KT RANGE INTO TONIGHT. SEAS STARTING OFF ONLY 1-2 FT AT GRAYS
REEF EARLY THIS MORNING WILL GRADUALLY BUILD THROUGH TONIGHT.
SLIGHT SURGING ALREADY NOTED AT DAYBREAK ALONG CHARLESTON COUNTY
AND MODEST PINCHING IS LIKELY THROUGH TONIGHT. SEAS 3-5 FT ARE
LIKELY SEAWARD FROM THE SAVANNAH AND CHARLESTON BUOYS LATER TODAY
AND TONIGHT.

SUNDAY THROUGH MONDAY NIGHT...CONDITIONS SHOULD REMAIN JUST BELOW
SMALL CRAFT ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE HOLDS INLAND
WHILE LOW PRESSURE SLOWLY DEVELOPS AND SHIFTS NORTHEAST ALONG THE
COAST. PERIODS OF RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS
THROUGH MONDAY NIGHT WHILE A COASTAL FRONT REMAINS ALONG THE COAST.
IN GENERAL...WINDS SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS UP TO
3-4 FT.

TUESDAY AND WEDNESDAY....CONDITIONS SHOULD BEGIN TO DETERIORATE AS A
COASTAL FRONT LIFTS NORTH WELL AHEAD OF A STRONG COLD FRONT THAT
EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WINDS ARE POSSIBLE AS THE COLD
FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY AFTERNOON AND NIGHT AS WINDS GUST TO 30-35 KT.
SEAS WILL ALSO BUILD UPWARDS TO 6-9 FT WEDNESDAY AFTERNOON INTO
EARLY WEDNESDAY NIGHT BEFORE IMPROVING LATE.

THURSDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS AS HIGH
PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
TONIGHT INTO MONDAY. SEA FOG COULD DEVELOP AS SLIGHTLY WARMER AIR
ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS WITHIN A SOUTH AND
SOUTHWEST FLOW LATE MONDAY INTO TUESDAY PRIOR TO WINDS INCREASING
ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...JRL
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 201541
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1041 AM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH TUESDAY NIGHT...
THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE WILL THEN
SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL SHORTWAVE IS PROGRESSING INTO NORTH GA AND THE SC
UPSTATE LATE THIS MORNING. MEANWHILE THE SUBTROPICAL JET STREAM
HAS SHIFTED EVER SO SLIGHTLY NORTH...MOVING THE REGION OF DIVERGENCE
TO OUR NORTH. WATER VAPOR IMAGERY SHOWS A LARGE AREA OF MID AND
HIGH LEVEL DRY AIR THAT WILL PUSH INTO THE REGION LATER THIS
AFTERNOON BEHIND THE SHORTWAVE. AT THE SURFACE WE HAVE WEAK HIGH
PRESSURE WEDGING DOWN THE EASTERN SEABOARD AND A SURFACE LOW
DEVELOPING OFF THE COAST. WE EXPECT FAIRLY WIDESPREAD LIGHT RAIN
TO CONTINUE INTO EARLY THIS AFTERNOON...ESPECIALLY ACROSS THE
NORTHERN HALF OF THE AREA CLOSER TO THE UPPER FORCING. BY MID TO
LATE AFTERNOON...ONCE PVA ASSOCIATED WITH THE SHORTWAVE SHIFTS OFF
THE COAST AND SOME DRIER AIR SHIFTS IN ALOFT...THE RAIN SHOULD
QUICKLY TAPER OFF FROM WEST TO EAST. CURRENT POP SCHEME LOOKS VERY
GOOD. CLOUDY SKIES SHOULD CONTINUE TODAY. TEMPS WILL REMAIN FAIRLY
STEADY THROUGH EARLY TO MID AFTERNOON DUE TO WEAK LOW-LEVEL COLD
ADVECTION AND EVAPORATIONAL COOLING. LATE IN THE DAY WE COULD SEE
A BRIEF REBOUND IN TEMPERATURES ONCE THE RAIN ENDS...BUT HIGHS
WILL NOT MAKE IT OUT OF THE 50S.

TONIGHT WE LIKE THE SREF REPRESENTATION OF LOW CLOUDS EXPANDING
INLAND THIS EVENING WITH STRATUS PERHAPS BUILDING DOWN IN SOME
AREAS BUT CONFIDENCE ONLY ENOUGH TO ADD PATCHY FOG TO THE FORECAST
OVERNIGHT AS LOW CLOUDS REMAIN MORE CERTAIN AT THIS POINT. LACK OF
FORCING SUGGESTS ANY LIGHT RAINS AROUND TONIGHT WOULD BE PATCHY
WITH SOME DRIZZLE AROUND THE REGION. POPS ONLY IN THE SLIGHT
CHANCE WERE MAINTAINED AND LOWS IN THE 40S ACROSS THE BOARD.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE DAY SHOULD START OFF SOMEWHAT DRY...BEFORE A PLUME OF
MOISTURE ADVECTS NORTH AS AN AREA OF LOW PRESSURE OVER THE NORTHEAST
GULF OF MEXICO SLOWLY SHIFTS OVER THE SOUTHEASTERN UNITED STATES
SUNDAY NIGHT. HAVE THEREFORE KEPT A GENERAL TREND OF RAMPING UP POPS
FROM SOUTHEAST GEORGIA TO SOUTHEAST SOUTH CAROLINA...WITH POPS
APPROACHING 80-90 SUNDAY NIGHT. GREATEST CHANCES OF PRECIP STILL
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...GIVEN THE LATEST TRACK ALONG THE SOUTHEAST
COAST. OVERALL HIGH TEMPS WILL BE DEPENDENT ON THE LOW TRACK...BUT
SHOULD REACH THE MID/UPPER 50S OVER MOST LOCATIONS AWAY FROM THE
COAST. TEMPS COULD PEAK NEAR 60 ALONG COASTAL AREAS IN SOUTHEAST
GEORGIA. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 40S AWAY FROM
THE COAST...AND IN THE LOW 50S ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE DURING THE AFTERNOON...BUT ELEVATED
PRECIP CHANCES WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE
EVENING WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE HIGH
PRESSURE WEDGE INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER
50S INLAND TO LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH
CAROLINA COAST.

MONDAY NIGHT INTO TUESDAY...MODELS CONTINUE TO SUGGEST INCREASING
PRECIP CHANCES LATE MONDAY NIGHT INTO TUESDAY AS A COASTAL FRONT
LIFTS NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A
PERIOD OF WARMING SHOULD OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
STRONG COLD FRONT TO THE WEST...WITH HIGH TEMPS APPROACHING THE
MID/UPPER 60S TUESDAY AFTERNOON. DEEPENING MOISTURE CHARACTERIZED BY
PWATS BETWEEN 1.8-1.9 INCHES ALONG WITH THE WARMER TEMPS SHOULD BE
SUFFICIENT FOR A FEW THUNDERSTORMS DURING THE AFTERNOON. GREATEST
CHANCES SHOULD OCCUR OVER SOUTHEAST GEORGIA WHERE SBCAPES APPROACH
800 J/KG AND MID LVL LAPSE RATES ARE NEAR 7 C/KM.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
GRADUALLY DETERIORATING CIGS ANTICIPATED THIS MORNING PER LATEST
FORECAST SOUNDINGS AT KCHS/KSAV. AS MOISTURE DEEPENS WITH THE
UPPER DISTURBANCE APPROACHING AND SOME INFLUX OF ATLC MOISTURE...
CIGS SHOULD FALL TO MVFR LEVELS BY MIDDAY WITH A CHANCE OF IFR CIGS
THIS AFTERNOON AT EITHER TERMINAL. CONFIDENCE IN LOWER CIGS INCREASES
TONIGHT AS A WEDGE INVERSION STRENGTHENS AND STRATUS EXPANDS AND
LOWERS. FORECAST 06Z SOUNDINGS NOT CLEAR CUT HOWEVER AND VARY GREATER
FROM GFS SOUNDINGS AT THIS TIME. WE TRENDED INTO IFR RANGE AFTER
MIDNIGHT ON THIS TAF CYCLE AND INTRODUCED MVFR VSBYS IN FOG. RAIN
SHOULD TAPER OFF AT KCHS LATE TODAY AND BRUSH KSAV THROUGH EARLY
TO MID AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH MONDAY NIGHT WHILE
A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY INTO WEDNESDAY AFTERNOON AS A
STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND POSSIBLY
THUNDERSTORMS. WINDY CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF
FROPA ON WEDNESDAY.

&&

.MARINE...
A WAVE OF LOW PRESSURE DEVELOPING ALONG THE WEST WALL OF THE GULF
STREAM TODAY AND DRIFTING ENE THROUGH TONIGHT. HIGH PRES WILL WEDGE
IN FROM THE NORTH IN THE WAKE OF THIS LOW AND BEGIN TO PINCH THE
PRES GRADIENT OFF THE COAST. A 4-6 MILLIBAR PRES GRADIENT FROM THE
GULF STREAM TO THE LAND WILL LIKELY ANCHOR A NE FLOW IN THE 15 TO
20 KT RANGE INTO TONIGHT. SEAS STARTING OFF ONLY 1-2 FT AT GRAYS
REEF EARLY THIS MORNING WILL GRADUALLY BUILD THROUGH TONIGHT.
SLIGHT SURGING ALREADY NOTED AT DAYBREAK ALONG CHARLESTON COUNTY
AND MODEST PINCHING IS LIKELY THROUGH TONIGHT. SEAS 3-5 FT ARE
LIKELY SEAWARD FROM THE SAVANNAH AND CHARLESTON BUOYS LATER TODAY
AND TONIGHT.

SUNDAY THROUGH MONDAY NIGHT...CONDITIONS SHOULD REMAIN JUST BELOW
SMALL CRAFT ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE HOLDS INLAND
WHILE LOW PRESSURE SLOWLY DEVELOPS AND SHIFTS NORTHEAST ALONG THE
COAST. PERIODS OF RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS
THROUGH MONDAY NIGHT WHILE A COASTAL FRONT REMAINS ALONG THE COAST.
IN GENERAL...WINDS SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS UP TO
3-4 FT.

TUESDAY AND WEDNESDAY....CONDITIONS SHOULD BEGIN TO DETERIORATE AS A
COASTAL FRONT LIFTS NORTH WELL AHEAD OF A STRONG COLD FRONT THAT
EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WINDS ARE POSSIBLE AS THE COLD
FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY AFTERNOON AND NIGHT AS WINDS GUST TO 30-35 KT.
SEAS WILL ALSO BUILD UPWARDS TO 6-9 FT WEDNESDAY AFTERNOON INTO
EARLY WEDNESDAY NIGHT BEFORE IMPROVING LATE.

THURSDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS AS HIGH
PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
TONIGHT INTO MONDAY. SEA FOG COULD DEVELOP AS SLIGHTLY WARMER AIR
ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS WITHIN A SOUTH AND
SOUTHWEST FLOW LATE MONDAY INTO TUESDAY PRIOR TO WINDS INCREASING
ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...JRL
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 201226
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
726 AM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH TUESDAY NIGHT...
THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE WILL THEN
SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING A BROAD BAROCLINIC ZONE FROM THE LOWER GULF COAST
ACROSS GEORGIA AND SOUTH CAROLINA WAS BECOMING BETTER DEFINED AS A MID
LEVEL SHORT WAVE SWINGS ENE ACROSS THE GULF COAST STATES. SURFACE HIGH
PRES WILL BUILD FROM THE OHIO VALLEY INTO THE MID ATLC REGION TODAY
WHILE WEAK SECONDARY SURFACE CYCLONGENESIS TAKES FORM OFF OUR COAST.
COOLER N TO NE FLOW ENSUES OVER THE FORECAST AREA WHILE WIDESPREAD
CLOUDS AND LIGHT RAINS START THE DAY. THIS IS A STRONG SIGNAL THAT
TEMPS WILL STRUGGLE TO MOVE MUCH THIS MORNING. AS THE BACK EDGE OF
THE RAIN SHIELD SLIDES INTO THE PICTURE BY THIS AFTERNOON...POTENTIAL
FOR TEMP RECOVERY LOOKS FAIRLY LIMITED AND LIMITED TO SOUTH GEORGIA.
A FAIRLY DEEP LAYER OF DRIER AIR ATOP THE BOUNDARY LAYER TO ABOUT
8 KFT WORKS IN FROM THE WSW AND EFFECTIVELY SHUTS DOWN THE RAINS
FOR ALL BUT PARTS OF OUR NORTHERN ZONES IN THE CHARLESTON AREA BY
MID-LATE AFTERNOON. IT IS A BIT UNCLEAR WHETHER THIS DRIER AIR
ABOVE WILL TRAP A LOT OF LOWER CLOUDS INITIALLY BUT WITH PLENTY OF
MID AND UPPER LEVEL MOISTURE LINGERING LATER IN THE DAY...CONFIDENCE
IS VERY GOOD THAT CLOUDS PREVAIL FOR THE ENTIRE FORECAST AREA.
CATEGORICAL POPS ACROSS THE BULK OF THE REGION THIS MORNING WILL
TRIM DOWNWARD INTO LIKELY RANGES TO THE N OF I-16 BY 18Z AND THEN
ONLY CHANCE POPS BY SUNSET ACROSS THE CHARLESTON AREA. QPF LIMITED
TO AMOUNTS LESS THAN 1/4 INCH NORTHERN ZONES WITH MANY AREAS ALONG
AND SOUTH OF I-16 MANAGING TO MEASURE WITH ONLY LIGHT AMOUNTS.

TONIGHT WE LIKE THE SREF REPRESENTATION OF LOW CLOUDS EXPANDING
INLAND THIS EVENING WITH STRATUS PERHAPS BUILDING DOWN IN SOME
AREAS BUT CONFIDENCE ONLY ENOUGH TO ADD PATCHY FOG TO THE FORECAST
OVERNIGHT AS LOW CLOUDS REMAIN MORE CERTAIN AT THIS POINT. LACK OF
FORCING SUGGESTS ANY LIGHT RAINS AROUND TONIGHT WOULD BE PATCHY WITH
SOME DRIZZLE AROUND THE REGION. POPS ONLY IN THE SLIGHT CHANCE WERE
MAINTAINED AND LOWS IN THE 40S ACROSS THE BOARD.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE DAY SHOULD START OFF SOMEWHAT DRY...BEFORE A PLUME OF
MOISTURE ADVECTS NORTH AS AN AREA OF LOW PRESSURE OVER THE NORTHEAST
GULF OF MEXICO SLOWLY SHIFTS OVER THE SOUTHEASTERN UNITED STATES
SUNDAY NIGHT. HAVE THEREFORE KEPT A GENERAL TREND OF RAMPING UP POPS
FROM SOUTHEAST GEORGIA TO SOUTHEAST SOUTH CAROLINA...WITH POPS
APPROACHING 80-90 SUNDAY NIGHT. GREATEST CHANCES OF PRECIP STILL
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...GIVEN THE LATEST TRACK ALONG THE SOUTHEAST
COAST. OVERALL HIGH TEMPS WILL BE DEPENDENT ON THE LOW TRACK...BUT
SHOULD REACH THE MID/UPPER 50S OVER MOST LOCATIONS AWAY FROM THE
COAST. TEMPS COULD PEAK NEAR 60 ALONG COASTAL AREAS IN SOUTHEAST
GEORGIA. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 40S AWAY FROM
THE COAST...AND IN THE LOW 50S ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE DURING THE AFTERNOON...BUT ELEVATED
PRECIP CHANCES WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE
EVENING WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE HIGH
PRESSURE WEDGE INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER
50S INLAND TO LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH
CAROLINA COAST.

MONDAY NIGHT INTO TUESDAY...MODELS CONTINUE TO SUGGEST INCREASING
PRECIP CHANCES LATE MONDAY NIGHT INTO TUESDAY AS A COASTAL FRONT
LIFTS NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A
PERIOD OF WARMING SHOULD OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
STRONG COLD FRONT TO THE WEST...WITH HIGH TEMPS APPROACHING THE
MID/UPPER 60S TUESDAY AFTERNOON. DEEPENING MOISTURE CHARACTERIZED BY
PWATS BETWEEN 1.8-1.9 INCHES ALONG WITH THE WARMER TEMPS SHOULD BE
SUFFICIENT FOR A FEW THUNDERSTORMS DURING THE AFTERNOON. GREATEST
CHANCES SHOULD OCCUR OVER SOUTHEAST GEORGIA WHERE SBCAPES APPROACH
800 J/KG AND MID LVL LAPSE RATES ARE NEAR 7 C/KM.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
GRADUALLY DETERIORATING CIGS ANTICIPATED THIS MORNING PER LATEST
FORECAST SOUNDINGS AT KCHS/KSAV. AS MOISTURE DEEPENS WITH THE
UPPER DISTURBANCE APPROACHING AND SOME INFLUX OF ATLC MOISTURE...
CIGS SHOULD FALL TO MVFR LEVELS BY MIDDAY WITH A CHANCE OF IFR CIGS
THIS AFTERNOON AT EITHER TERMINAL. CONFIDENCE IN LOWER CIGS INCREASES
TONIGHT AS A WEDGE INVERSION STRENGTHENS AND STRATUS EXPANDS AND
LOWERS. FORECAST 06Z SOUNDINGS NOT CLEAR CUT HOWEVER AND VARY GREATER
FROM GFS SOUNDINGS AT THIS TIME. WE TRENDED INTO IFR RANGE AFTER
MIDNIGHT ON THIS TAF CYCLE AND INTRODUCED MVFR VSBYS IN FOG. RAIN
SHOULD TAPER OFF AT KCHS LATE TODAY AND BRUSH KSAV THROUGH EARLY
TO MID AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH MONDAY NIGHT WHILE
A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY INTO WEDNESDAY AFTERNOON AS A
STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND POSSIBLY
THUNDERSTORMS. WINDY CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF
FROPA ON WEDNESDAY.

&&

.MARINE...
A WAVE OF LOW PRESSURE DEVELOPING ALONG THE WEST WALL OF THE GULF
STREAM TODAY AND DRIFTING ENE THROUGH TONIGHT. HIGH PRES WILL WEDGE
IN FROM THE NORTH IN THE WAKE OF THIS LOW AND BEGIN TO PINCH THE
PRES GRADIENT OFF THE COAST. A 4-6 MILLIBAR PRES GRADIENT FROM THE
GULF STREAM TO THE LAND WILL LIKELY ANCHOR A NE FLOW IN THE 15 TO
20 KT RANGE INTO TONIGHT. SEAS STARTING OFF ONLY 1-2 FT AT GRAYS
REEF EARLY THIS MORNING WILL GRADUALLY BUILD THROUGH TONIGHT.
SLIGHT SURGING ALREADY NOTED AT DAYBREAK ALONG CHARLESTON COUNTY
AND MODEST PINCHING IS LIKELY THROUGH TONIGHT. SEAS 3-5 FT ARE
LIKELY SEAWARD FROM THE SAVANNAH AND CHARLESTON BUOYS LATER TODAY
AND TONIGHT.

SUNDAY THROUGH MONDAY NIGHT...CONDITIONS SHOULD REMAIN JUST BELOW
SMALL CRAFT ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE HOLDS INLAND
WHILE LOW PRESSURE SLOWLY DEVELOPS AND SHIFTS NORTHEAST ALONG THE
COAST. PERIODS OF RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS
THROUGH MONDAY NIGHT WHILE A COASTAL FRONT REMAINS ALONG THE COAST.
IN GENERAL...WINDS SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS UP TO
3-4 FT.

TUESDAY AND WEDNESDAY....CONDITIONS SHOULD BEGIN TO DETERIORATE AS A
COASTAL FRONT LIFTS NORTH WELL AHEAD OF A STRONG COLD FRONT THAT
EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WINDS ARE POSSIBLE AS THE COLD
FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY AFTERNOON AND NIGHT AS WINDS GUST TO 30-35 KT.
SEAS WILL ALSO BUILD UPWARDS TO 6-9 FT WEDNESDAY AFTERNOON INTO
EARLY WEDNESDAY NIGHT BEFORE IMPROVING LATE.

THURSDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS AS HIGH
PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...LOW STRATUS DECKS COULD EQUATE TO REDUCED VISIBILITIES
TONIGHT INTO MONDAY. SEA FOG COULD DEVELOP AS SLIGHTLY WARMER AIR
ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS WITHIN A SOUTH AND
SOUTHWEST FLOW LATE MONDAY INTO TUESDAY PRIOR TO WINDS INCREASING
ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 201005
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
505 AM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH TUESDAY NIGHT...
THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE WILL THEN
SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...WIDESPREAD LIGHT RAINFALL ECHOES ON RADAR HAVE NOT BEEN
TRANSLATING TO MEASURABLE RAINS ACROSS THE REGION AS OF 3 AM. QUITE
A BIT OF VIRGA OUT THERE INITIALLY. LOWER LEVELS WERE GRADUALLY
SATURATING AND EXPECT MOST OF OUR FORECAST AREA WILL SEE SOME LIGHT
MEASURABLE RAINFALL PRIOR TO DAYBREAK. THE CLOUD COVER AND INCREASED
LOW LEVEL MOISTURE RESPONSIBLE FOR A FAIRLY UNIFORM SURFACE THERMAL
FIELD WITH READINGS IN THE 45-50 DEGREE RANGE.

EARLY THIS MORNING A BROAD BAROCLINIC ZONE FROM THE LOWER GULF COAST
ACROSS GEORGIA AND SOUTH CAROLINA WAS BECOMING BETTER DEFINED AS A
MID LEVEL SHORT WAVE SWINGS ENE ACROSS THE GULF COAST STATES. SURFACE
HIGH PRES WILL BUILD FROM THE OHIO VALLEY INTO THE MID ATLC REGION
TODAY WHILE WEAK SECONDARY SURFACE CYCLONGENESIS TAKES FORM OFF
OUR COAST. COOLER N TO NE FLOW ENSUES OVER THE FORECAST AREA WHILE
WIDESPREAD CLOUDS AND LIGHT RAINS START THE DAY. THIS IS A STRONG
SIGNAL THAT TEMPS WILL STRUGGLE TO MOVE MUCH THIS MORNING. AS THE BACK
EDGE OF THE RAIN SHIELD SLIDES INTO THE PICTURE BY THIS AFTERNOON...
POTENTIAL FOR TEMP RECOVERY LOOKS FAIRLY LIMITED AND LIMITED TO SOUTH
GEORGIA. A FAIRLY DEEP LAYER OF DRIER AIR ATOP THE BOUNDARY LAYER TO
ABOUT 8 KFT WORKS IN FROM THE WSW AND EFFECTIVELY SHUTS DOWN THE RAINS
FOR ALL BUT PARTS OF OUR NORTHERN ZONES IN THE CHARLESTON AREA BY
MID-LATE AFTERNOON. IT IS A BIT UNCLEAR WHETHER THIS DRIER AIR ABOVE
WILL TRAP A LOT OF LOWER CLOUDS INITIALLY BUT WITH PLENTY OF MID AND
UPPER LEVEL MOISTURE LINGERING LATER IN THE DAY...CONFIDENCE IS VERY
GOOD THAT CLOUDS PREVAIL FOR THE ENTIRE FORECAST AREA. CATEGORICAL
POPS ACROSS THE BULK OF THE REGION THIS MORNING WILL TRIM DOWNWARD
INTO LIKELY RANGES TO THE N OF I-16 BY 18Z AND THEN ONLY CHANCE
POPS BY SUNSET ACROSS THE CHARLESTON AREA. QPF LIMITED TO AMOUNTS
LESS THAN 1/4 INCH NORTHERN ZONES WITH MANY AREAS ALONG AND SOUTH
OF I-16 MANAGING TO MEASURE WITH ONLY LIGHT AMOUNTS.

TONIGHT WE LIKE THE SREF REPRESENTATION OF LOW CLOUDS EXPANDING
SOUTHWARD THIS EVENING WITH STRATUS PERHAPS BUILDING DOWN IN SOME
AREAS BUT CONFIDENCE ONLY ENOUGH TO ADD PATCHY FOG TO THE FORECAST
OVERNIGHT AS LOW CLOUDS REMAIN MORE CERTAIN AT THIS POINT. LACK OF
FORCING SUGGESTS ANY LIGHT RAINS AROUND TONIGHT WOULD BE PATCHY WITH
SOME DRIZZLE AROUND THE REGION. POPS ONLY IN THE SLIGHT CHANCE WERE
MAINTAINED AND LOWS IN THE 40S ACROSS THE BOARD.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE DAY SHOULD START OFF SOMEWHAT DRY...BEFORE A PLUME OF
MOISTURE ADVECTS NORTH AS AN AREA OF LOW PRESSURE OVER THE NORTHEAST
GULF OF MEXICO SLOWLY SHIFTS OVER THE SOUTHEASTERN UNITED STATES
SUNDAY NIGHT. HAVE THEREFORE KEPT A GENERAL TREND OF RAMPING UP POPS
FROM SOUTHEAST GEORGIA TO SOUTHEAST SOUTH CAROLINA...WITH POPS
APPROACHING 80-90 SUNDAY NIGHT. GREATEST CHANCES OF PRECIP STILL
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...GIVEN THE LATEST TRACK ALONG THE SOUTHEAST
COAST. OVERALL HIGH TEMPS WILL BE DEPENDENT ON THE LOW TRACK...BUT
SHOULD REACH THE MID/UPPER 50S OVER MOST LOCATIONS AWAY FROM THE
COAST. TEMPS COULD PEAK NEAR 60 ALONG COASTAL AREAS IN SOUTHEAST
GEORGIA. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 40S AWAY FROM
THE COAST...AND IN THE LOW 50S ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE DURING THE AFTERNOON...BUT ELEVATED
PRECIP CHANCES WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE
EVENING WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE HIGH
PRESSURE WEDGE INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER
50S INLAND TO LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH
CAROLINA COAST.

MONDAY NIGHT INTO TUESDAY...MODELS CONTINUE TO SUGGEST INCREASING
PRECIP CHANCES LATE MONDAY NIGHT INTO TUESDAY AS A COASTAL FRONT
LIFTS NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A
PERIOD OF WARMING SHOULD OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
STRONG COLD FRONT TO THE WEST...WITH HIGH TEMPS APPROACHING THE
MID/UPPER 60S TUESDAY AFTERNOON. DEEPENING MOISTURE CHARACTERIZED BY
PWATS BETWEEN 1.8-1.9 INCHES ALONG WITH THE WARMER TEMPS SHOULD BE
SUFFICIENT FOR A FEW THUNDERSTORMS DURING THE AFTERNOON. GREATEST
CHANCES SHOULD OCCUR OVER SOUTHEAST GEORGIA WHERE SBCAPES APPROACH
800 J/KG AND MID LVL LAPSE RATES ARE NEAR 7 C/KM.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
THE MAIN FORECAST PROBLEM IS WHEN AND WHERE LOW CLOUDS FILL-IN AFTER
A DEVELOPING SURFACE WAVE OFFSHORE DEPARTS AND A WEDGE INVERSION
CAN SOLIDLY LOCK IN. GIVEN THE LATEST SREF PROGS AND 00Z NAM...IT
MAKE TAKE UNTIL LATER TODAY IN AT KCHS AND THIS EVENING AT KSAV.
WE MADE SOME MINOR ADJUSTMENTS TO THE PREVIOUS TAF CYCLE BUT KEPT
PERSISTENCE OVERALL. MVFR CIGS ARE LIKELY AT KCHS BY THIS AFTERNOON
AND MVFR/IFR TONIGHT. AT KSAV...MVFR CIGS POSSIBLE AFTER SUNRISE
THEN CONFIDENCE INCREASES IN MVFR GOING IFR TONIGHT AS THE INVERSION
STRENGTHENS.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH MONDAY NIGHT WHILE
A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY INTO WEDNESDAY AFTERNOON AS A
STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND POSSIBLY
THUNDERSTORMS. WINDY CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF
FROPA ON WEDNESDAY.

&&

.MARINE...
A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE WEST WALL OF THE GULF
STREAM TODAY AND DRIFT ENE THROUGH TONIGHT. HIGH PRES WILL WEDGE IN
FROM THE NORTH IN THE WAKE OF THIS LOW AND BEGIN TO PINCH THE PRES
GRADIENT OFF THE COAST. A 4-6 MILLIBAR PRES GRADIENT FROM THE GULF
STREAM TO THE LAND WILL LIKELY ANCHOR A NE FLOW IN THE 15 TO 20 KT
RANGE LATER THIS MORNING INTO TONIGHT. SEAS STARTING OFF ONLY 1-2
FT EARLY THIS MORNING WILL GRADUALLY BUILD THROUGH TONIGHT. SEAS
3-5 FT ARE LIKELY SEAWARD FROM THE SAVANNAH AND CHARLESTON BUOYS
TONIGHT.

SUNDAY THROUGH MONDAY NIGHT...CONDITIONS SHOULD REMAIN JUST BELOW
SMALL CRAFT ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE HOLDS INLAND
WHILE LOW PRESSURE SLOWLY DEVELOPS AND SHIFTS NORTHEAST ALONG THE
COAST. PERIODS OF RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS
THROUGH MONDAY NIGHT WHILE A COASTAL FRONT REMAINS ALONG THE COAST.
IN GENERAL...WINDS SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS UP TO
3-4 FT.

TUESDAY AND WEDNESDAY....CONDITIONS SHOULD BEGIN TO DETERIORATE AS A
COASTAL FRONT LIFTS NORTH WELL AHEAD OF A STRONG COLD FRONT THAT
EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WINDS ARE POSSIBLE AS THE COLD
FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY AFTERNOON AND NIGHT AS WINDS GUST TO 30-35 KT.
SEAS WILL ALSO BUILD UPWARDS TO 6-9 FT WEDNESDAY AFTERNOON INTO
EARLY WEDNESDAY NIGHT BEFORE IMPROVING LATE.

THURSDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS AS HIGH
PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS COULD EQUATE
TO REDUCED VISIBILITIES TONIGHT INTO MONDAY. SEA FOG COULD DEVELOP
AS SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE MONDAY INTO TUESDAY PRIOR
TO WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND
TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 201005
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
505 AM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH TUESDAY NIGHT...
THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE WILL THEN
SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...WIDESPREAD LIGHT RAINFALL ECHOES ON RADAR HAVE NOT BEEN
TRANSLATING TO MEASURABLE RAINS ACROSS THE REGION AS OF 3 AM. QUITE
A BIT OF VIRGA OUT THERE INITIALLY. LOWER LEVELS WERE GRADUALLY
SATURATING AND EXPECT MOST OF OUR FORECAST AREA WILL SEE SOME LIGHT
MEASURABLE RAINFALL PRIOR TO DAYBREAK. THE CLOUD COVER AND INCREASED
LOW LEVEL MOISTURE RESPONSIBLE FOR A FAIRLY UNIFORM SURFACE THERMAL
FIELD WITH READINGS IN THE 45-50 DEGREE RANGE.

EARLY THIS MORNING A BROAD BAROCLINIC ZONE FROM THE LOWER GULF COAST
ACROSS GEORGIA AND SOUTH CAROLINA WAS BECOMING BETTER DEFINED AS A
MID LEVEL SHORT WAVE SWINGS ENE ACROSS THE GULF COAST STATES. SURFACE
HIGH PRES WILL BUILD FROM THE OHIO VALLEY INTO THE MID ATLC REGION
TODAY WHILE WEAK SECONDARY SURFACE CYCLONGENESIS TAKES FORM OFF
OUR COAST. COOLER N TO NE FLOW ENSUES OVER THE FORECAST AREA WHILE
WIDESPREAD CLOUDS AND LIGHT RAINS START THE DAY. THIS IS A STRONG
SIGNAL THAT TEMPS WILL STRUGGLE TO MOVE MUCH THIS MORNING. AS THE BACK
EDGE OF THE RAIN SHIELD SLIDES INTO THE PICTURE BY THIS AFTERNOON...
POTENTIAL FOR TEMP RECOVERY LOOKS FAIRLY LIMITED AND LIMITED TO SOUTH
GEORGIA. A FAIRLY DEEP LAYER OF DRIER AIR ATOP THE BOUNDARY LAYER TO
ABOUT 8 KFT WORKS IN FROM THE WSW AND EFFECTIVELY SHUTS DOWN THE RAINS
FOR ALL BUT PARTS OF OUR NORTHERN ZONES IN THE CHARLESTON AREA BY
MID-LATE AFTERNOON. IT IS A BIT UNCLEAR WHETHER THIS DRIER AIR ABOVE
WILL TRAP A LOT OF LOWER CLOUDS INITIALLY BUT WITH PLENTY OF MID AND
UPPER LEVEL MOISTURE LINGERING LATER IN THE DAY...CONFIDENCE IS VERY
GOOD THAT CLOUDS PREVAIL FOR THE ENTIRE FORECAST AREA. CATEGORICAL
POPS ACROSS THE BULK OF THE REGION THIS MORNING WILL TRIM DOWNWARD
INTO LIKELY RANGES TO THE N OF I-16 BY 18Z AND THEN ONLY CHANCE
POPS BY SUNSET ACROSS THE CHARLESTON AREA. QPF LIMITED TO AMOUNTS
LESS THAN 1/4 INCH NORTHERN ZONES WITH MANY AREAS ALONG AND SOUTH
OF I-16 MANAGING TO MEASURE WITH ONLY LIGHT AMOUNTS.

TONIGHT WE LIKE THE SREF REPRESENTATION OF LOW CLOUDS EXPANDING
SOUTHWARD THIS EVENING WITH STRATUS PERHAPS BUILDING DOWN IN SOME
AREAS BUT CONFIDENCE ONLY ENOUGH TO ADD PATCHY FOG TO THE FORECAST
OVERNIGHT AS LOW CLOUDS REMAIN MORE CERTAIN AT THIS POINT. LACK OF
FORCING SUGGESTS ANY LIGHT RAINS AROUND TONIGHT WOULD BE PATCHY WITH
SOME DRIZZLE AROUND THE REGION. POPS ONLY IN THE SLIGHT CHANCE WERE
MAINTAINED AND LOWS IN THE 40S ACROSS THE BOARD.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE DAY SHOULD START OFF SOMEWHAT DRY...BEFORE A PLUME OF
MOISTURE ADVECTS NORTH AS AN AREA OF LOW PRESSURE OVER THE NORTHEAST
GULF OF MEXICO SLOWLY SHIFTS OVER THE SOUTHEASTERN UNITED STATES
SUNDAY NIGHT. HAVE THEREFORE KEPT A GENERAL TREND OF RAMPING UP POPS
FROM SOUTHEAST GEORGIA TO SOUTHEAST SOUTH CAROLINA...WITH POPS
APPROACHING 80-90 SUNDAY NIGHT. GREATEST CHANCES OF PRECIP STILL
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...GIVEN THE LATEST TRACK ALONG THE SOUTHEAST
COAST. OVERALL HIGH TEMPS WILL BE DEPENDENT ON THE LOW TRACK...BUT
SHOULD REACH THE MID/UPPER 50S OVER MOST LOCATIONS AWAY FROM THE
COAST. TEMPS COULD PEAK NEAR 60 ALONG COASTAL AREAS IN SOUTHEAST
GEORGIA. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 40S AWAY FROM
THE COAST...AND IN THE LOW 50S ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE DURING THE AFTERNOON...BUT ELEVATED
PRECIP CHANCES WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE
EVENING WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE HIGH
PRESSURE WEDGE INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER
50S INLAND TO LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH
CAROLINA COAST.

MONDAY NIGHT INTO TUESDAY...MODELS CONTINUE TO SUGGEST INCREASING
PRECIP CHANCES LATE MONDAY NIGHT INTO TUESDAY AS A COASTAL FRONT
LIFTS NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A
PERIOD OF WARMING SHOULD OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
STRONG COLD FRONT TO THE WEST...WITH HIGH TEMPS APPROACHING THE
MID/UPPER 60S TUESDAY AFTERNOON. DEEPENING MOISTURE CHARACTERIZED BY
PWATS BETWEEN 1.8-1.9 INCHES ALONG WITH THE WARMER TEMPS SHOULD BE
SUFFICIENT FOR A FEW THUNDERSTORMS DURING THE AFTERNOON. GREATEST
CHANCES SHOULD OCCUR OVER SOUTHEAST GEORGIA WHERE SBCAPES APPROACH
800 J/KG AND MID LVL LAPSE RATES ARE NEAR 7 C/KM.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
THE MAIN FORECAST PROBLEM IS WHEN AND WHERE LOW CLOUDS FILL-IN AFTER
A DEVELOPING SURFACE WAVE OFFSHORE DEPARTS AND A WEDGE INVERSION
CAN SOLIDLY LOCK IN. GIVEN THE LATEST SREF PROGS AND 00Z NAM...IT
MAKE TAKE UNTIL LATER TODAY IN AT KCHS AND THIS EVENING AT KSAV.
WE MADE SOME MINOR ADJUSTMENTS TO THE PREVIOUS TAF CYCLE BUT KEPT
PERSISTENCE OVERALL. MVFR CIGS ARE LIKELY AT KCHS BY THIS AFTERNOON
AND MVFR/IFR TONIGHT. AT KSAV...MVFR CIGS POSSIBLE AFTER SUNRISE
THEN CONFIDENCE INCREASES IN MVFR GOING IFR TONIGHT AS THE INVERSION
STRENGTHENS.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH MONDAY NIGHT WHILE
A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY INTO WEDNESDAY AFTERNOON AS A
STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND POSSIBLY
THUNDERSTORMS. WINDY CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF
FROPA ON WEDNESDAY.

&&

.MARINE...
A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE WEST WALL OF THE GULF
STREAM TODAY AND DRIFT ENE THROUGH TONIGHT. HIGH PRES WILL WEDGE IN
FROM THE NORTH IN THE WAKE OF THIS LOW AND BEGIN TO PINCH THE PRES
GRADIENT OFF THE COAST. A 4-6 MILLIBAR PRES GRADIENT FROM THE GULF
STREAM TO THE LAND WILL LIKELY ANCHOR A NE FLOW IN THE 15 TO 20 KT
RANGE LATER THIS MORNING INTO TONIGHT. SEAS STARTING OFF ONLY 1-2
FT EARLY THIS MORNING WILL GRADUALLY BUILD THROUGH TONIGHT. SEAS
3-5 FT ARE LIKELY SEAWARD FROM THE SAVANNAH AND CHARLESTON BUOYS
TONIGHT.

SUNDAY THROUGH MONDAY NIGHT...CONDITIONS SHOULD REMAIN JUST BELOW
SMALL CRAFT ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE HOLDS INLAND
WHILE LOW PRESSURE SLOWLY DEVELOPS AND SHIFTS NORTHEAST ALONG THE
COAST. PERIODS OF RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS
THROUGH MONDAY NIGHT WHILE A COASTAL FRONT REMAINS ALONG THE COAST.
IN GENERAL...WINDS SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS UP TO
3-4 FT.

TUESDAY AND WEDNESDAY....CONDITIONS SHOULD BEGIN TO DETERIORATE AS A
COASTAL FRONT LIFTS NORTH WELL AHEAD OF A STRONG COLD FRONT THAT
EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WINDS ARE POSSIBLE AS THE COLD
FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY AFTERNOON AND NIGHT AS WINDS GUST TO 30-35 KT.
SEAS WILL ALSO BUILD UPWARDS TO 6-9 FT WEDNESDAY AFTERNOON INTO
EARLY WEDNESDAY NIGHT BEFORE IMPROVING LATE.

THURSDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS AS HIGH
PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS COULD EQUATE
TO REDUCED VISIBILITIES TONIGHT INTO MONDAY. SEA FOG COULD DEVELOP
AS SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE MONDAY INTO TUESDAY PRIOR
TO WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND
TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 201005
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
505 AM EST SAT DEC 20 2014

.SYNOPSIS...
UNSETTLED WEATHER IS EXPECTED THROUGH TUESDAY AS SEVERAL DISTURBANCES
MOVE OVER THE REGION. A STRONG COLD FRONT WILL APPROACH TUESDAY NIGHT...
THEN SHIFT THROUGH THE AREA ON WEDNESDAY. DRY HIGH PRESSURE WILL THEN
SETTLE OVER THE SOUTHEAST THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...WIDESPREAD LIGHT RAINFALL ECHOES ON RADAR HAVE NOT BEEN
TRANSLATING TO MEASURABLE RAINS ACROSS THE REGION AS OF 3 AM. QUITE
A BIT OF VIRGA OUT THERE INITIALLY. LOWER LEVELS WERE GRADUALLY
SATURATING AND EXPECT MOST OF OUR FORECAST AREA WILL SEE SOME LIGHT
MEASURABLE RAINFALL PRIOR TO DAYBREAK. THE CLOUD COVER AND INCREASED
LOW LEVEL MOISTURE RESPONSIBLE FOR A FAIRLY UNIFORM SURFACE THERMAL
FIELD WITH READINGS IN THE 45-50 DEGREE RANGE.

EARLY THIS MORNING A BROAD BAROCLINIC ZONE FROM THE LOWER GULF COAST
ACROSS GEORGIA AND SOUTH CAROLINA WAS BECOMING BETTER DEFINED AS A
MID LEVEL SHORT WAVE SWINGS ENE ACROSS THE GULF COAST STATES. SURFACE
HIGH PRES WILL BUILD FROM THE OHIO VALLEY INTO THE MID ATLC REGION
TODAY WHILE WEAK SECONDARY SURFACE CYCLONGENESIS TAKES FORM OFF
OUR COAST. COOLER N TO NE FLOW ENSUES OVER THE FORECAST AREA WHILE
WIDESPREAD CLOUDS AND LIGHT RAINS START THE DAY. THIS IS A STRONG
SIGNAL THAT TEMPS WILL STRUGGLE TO MOVE MUCH THIS MORNING. AS THE BACK
EDGE OF THE RAIN SHIELD SLIDES INTO THE PICTURE BY THIS AFTERNOON...
POTENTIAL FOR TEMP RECOVERY LOOKS FAIRLY LIMITED AND LIMITED TO SOUTH
GEORGIA. A FAIRLY DEEP LAYER OF DRIER AIR ATOP THE BOUNDARY LAYER TO
ABOUT 8 KFT WORKS IN FROM THE WSW AND EFFECTIVELY SHUTS DOWN THE RAINS
FOR ALL BUT PARTS OF OUR NORTHERN ZONES IN THE CHARLESTON AREA BY
MID-LATE AFTERNOON. IT IS A BIT UNCLEAR WHETHER THIS DRIER AIR ABOVE
WILL TRAP A LOT OF LOWER CLOUDS INITIALLY BUT WITH PLENTY OF MID AND
UPPER LEVEL MOISTURE LINGERING LATER IN THE DAY...CONFIDENCE IS VERY
GOOD THAT CLOUDS PREVAIL FOR THE ENTIRE FORECAST AREA. CATEGORICAL
POPS ACROSS THE BULK OF THE REGION THIS MORNING WILL TRIM DOWNWARD
INTO LIKELY RANGES TO THE N OF I-16 BY 18Z AND THEN ONLY CHANCE
POPS BY SUNSET ACROSS THE CHARLESTON AREA. QPF LIMITED TO AMOUNTS
LESS THAN 1/4 INCH NORTHERN ZONES WITH MANY AREAS ALONG AND SOUTH
OF I-16 MANAGING TO MEASURE WITH ONLY LIGHT AMOUNTS.

TONIGHT WE LIKE THE SREF REPRESENTATION OF LOW CLOUDS EXPANDING
SOUTHWARD THIS EVENING WITH STRATUS PERHAPS BUILDING DOWN IN SOME
AREAS BUT CONFIDENCE ONLY ENOUGH TO ADD PATCHY FOG TO THE FORECAST
OVERNIGHT AS LOW CLOUDS REMAIN MORE CERTAIN AT THIS POINT. LACK OF
FORCING SUGGESTS ANY LIGHT RAINS AROUND TONIGHT WOULD BE PATCHY WITH
SOME DRIZZLE AROUND THE REGION. POPS ONLY IN THE SLIGHT CHANCE WERE
MAINTAINED AND LOWS IN THE 40S ACROSS THE BOARD.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...THE DAY SHOULD START OFF SOMEWHAT DRY...BEFORE A PLUME OF
MOISTURE ADVECTS NORTH AS AN AREA OF LOW PRESSURE OVER THE NORTHEAST
GULF OF MEXICO SLOWLY SHIFTS OVER THE SOUTHEASTERN UNITED STATES
SUNDAY NIGHT. HAVE THEREFORE KEPT A GENERAL TREND OF RAMPING UP POPS
FROM SOUTHEAST GEORGIA TO SOUTHEAST SOUTH CAROLINA...WITH POPS
APPROACHING 80-90 SUNDAY NIGHT. GREATEST CHANCES OF PRECIP STILL
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...GIVEN THE LATEST TRACK ALONG THE SOUTHEAST
COAST. OVERALL HIGH TEMPS WILL BE DEPENDENT ON THE LOW TRACK...BUT
SHOULD REACH THE MID/UPPER 50S OVER MOST LOCATIONS AWAY FROM THE
COAST. TEMPS COULD PEAK NEAR 60 ALONG COASTAL AREAS IN SOUTHEAST
GEORGIA. OVERNIGHT LOWS SHOULD RANGE IN THE MID/UPPER 40S AWAY FROM
THE COAST...AND IN THE LOW 50S ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE DURING THE AFTERNOON...BUT ELEVATED
PRECIP CHANCES WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE
EVENING WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE HIGH
PRESSURE WEDGE INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER
50S INLAND TO LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH
CAROLINA COAST.

MONDAY NIGHT INTO TUESDAY...MODELS CONTINUE TO SUGGEST INCREASING
PRECIP CHANCES LATE MONDAY NIGHT INTO TUESDAY AS A COASTAL FRONT
LIFTS NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A
PERIOD OF WARMING SHOULD OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
STRONG COLD FRONT TO THE WEST...WITH HIGH TEMPS APPROACHING THE
MID/UPPER 60S TUESDAY AFTERNOON. DEEPENING MOISTURE CHARACTERIZED BY
PWATS BETWEEN 1.8-1.9 INCHES ALONG WITH THE WARMER TEMPS SHOULD BE
SUFFICIENT FOR A FEW THUNDERSTORMS DURING THE AFTERNOON. GREATEST
CHANCES SHOULD OCCUR OVER SOUTHEAST GEORGIA WHERE SBCAPES APPROACH
800 J/KG AND MID LVL LAPSE RATES ARE NEAR 7 C/KM.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT TEMPS WILL REMAIN RATHER MILD AHEAD OF A COLD FRONT TO
THE WEST. WE COULD SEE A FEW THUNDERSTORMS BEFORE THE FRONT SHIFTS
OFFSHORE WEDNESDAY AFTERNOON. GUSTY WINDS SHOULD ALSO ACCOMPANY THE
FRONT AS STRONG COLD AIR ADVECTION OCCURS BEHIND IT. A MUCH
QUIETER/DRY PERIOD OF WEATHER IS THEN ANTICIPATED AS HIGH PRESSURE
BUILDS OVER THE REGION BEHIND THE FRONT STARTING WEDNESDAY NIGHT.
TEMPS WILL BE SLOW TO WARM THROUGH THURSDAY...UNTIL HIGH PRESSURE
BECOMES MORE CENTERED OVER THE WESTERN ATLANTIC. OVERALL HIGH TEMPS
SHOULD RANGE IN THE MID/UPPER 50S THURSDAY...BEFORE SOUTHERLY FLOW
RETURNS TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON
FRIDAY. TEMPS SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK. ANOTHER
COLD FRONT COULD APPROACH NEXT WEEKEND...BRINGING THE NEXT CHANCE OF
PRECIP TO THE AREA.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
THE MAIN FORECAST PROBLEM IS WHEN AND WHERE LOW CLOUDS FILL-IN AFTER
A DEVELOPING SURFACE WAVE OFFSHORE DEPARTS AND A WEDGE INVERSION
CAN SOLIDLY LOCK IN. GIVEN THE LATEST SREF PROGS AND 00Z NAM...IT
MAKE TAKE UNTIL LATER TODAY IN AT KCHS AND THIS EVENING AT KSAV.
WE MADE SOME MINOR ADJUSTMENTS TO THE PREVIOUS TAF CYCLE BUT KEPT
PERSISTENCE OVERALL. MVFR CIGS ARE LIKELY AT KCHS BY THIS AFTERNOON
AND MVFR/IFR TONIGHT. AT KSAV...MVFR CIGS POSSIBLE AFTER SUNRISE
THEN CONFIDENCE INCREASES IN MVFR GOING IFR TONIGHT AS THE INVERSION
STRENGTHENS.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS ARE
LIKELY WITH RAIN/SHOWERS AND LOW STRATUS THROUGH MONDAY NIGHT WHILE
A WEDGE OF HIGH PRESSURE PERSISTS INLAND AND WAVES OF LOW PRESSURE
LIFT NORTHEAST ACROSS THE NEARBY ATLANTIC. ADDITIONAL FLIGHT
RESTRICTIONS APPEAR LIKELY TUESDAY INTO WEDNESDAY AFTERNOON AS A
STRONG COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS AND POSSIBLY
THUNDERSTORMS. WINDY CONDITIONS SHOULD ALSO OCCUR NEAR THE TIME OF
FROPA ON WEDNESDAY.

&&

.MARINE...
A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE WEST WALL OF THE GULF
STREAM TODAY AND DRIFT ENE THROUGH TONIGHT. HIGH PRES WILL WEDGE IN
FROM THE NORTH IN THE WAKE OF THIS LOW AND BEGIN TO PINCH THE PRES
GRADIENT OFF THE COAST. A 4-6 MILLIBAR PRES GRADIENT FROM THE GULF
STREAM TO THE LAND WILL LIKELY ANCHOR A NE FLOW IN THE 15 TO 20 KT
RANGE LATER THIS MORNING INTO TONIGHT. SEAS STARTING OFF ONLY 1-2
FT EARLY THIS MORNING WILL GRADUALLY BUILD THROUGH TONIGHT. SEAS
3-5 FT ARE LIKELY SEAWARD FROM THE SAVANNAH AND CHARLESTON BUOYS
TONIGHT.

SUNDAY THROUGH MONDAY NIGHT...CONDITIONS SHOULD REMAIN JUST BELOW
SMALL CRAFT ADVISORY LEVELS AS A WEDGE OF HIGH PRESSURE HOLDS INLAND
WHILE LOW PRESSURE SLOWLY DEVELOPS AND SHIFTS NORTHEAST ALONG THE
COAST. PERIODS OF RAIN/SHOWERS ARE ANTICIPATED OVER THE WATERS
THROUGH MONDAY NIGHT WHILE A COASTAL FRONT REMAINS ALONG THE COAST.
IN GENERAL...WINDS SHOULD BE NO HIGHER THAN 15-20 KT WITH SEAS UP TO
3-4 FT.

TUESDAY AND WEDNESDAY....CONDITIONS SHOULD BEGIN TO DETERIORATE AS A
COASTAL FRONT LIFTS NORTH WELL AHEAD OF A STRONG COLD FRONT THAT
EVENTUALLY SHIFTS OVER THE WATERS WEDNESDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE OVER MOST WATERS AHEAD OF THE
FRONT...WHILE WINDS AND SEAS INCREASE/BUILD WITHIN A SOUTHERLY FLOW.
AT THIS TIME...CONDITIONS SHOULD REACH SMALL CRAFT ADVISORY LEVELS
NEAR DAYBREAK WEDNESDAY AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF
THE APPROACHING FRONT. GALE FORCE WINDS ARE POSSIBLE AS THE COLD
FRONT SHIFTS OFFSHORE WITH STRONG COLD AIR ADVECTION BEHIND IT. A
GALE WATCH/WARNING COULD EVENTUALLY BE NEEDED FOR A PORTION OF THE
WATERS WEDNESDAY AFTERNOON AND NIGHT AS WINDS GUST TO 30-35 KT.
SEAS WILL ALSO BUILD UPWARDS TO 6-9 FT WEDNESDAY AFTERNOON INTO
EARLY WEDNESDAY NIGHT BEFORE IMPROVING LATE.

THURSDAY...CONDITIONS WILL IMPROVE QUICKLY OVER ALL WATERS AS HIGH
PRESSURE BECOMES CENTERED JUST SOUTH OF THE WATERS. WINDS/SEAS
SHOULD LOWER BELOW SMALL CRAFT ADVISORY LEVELS FOR ALL WATERS AROUND
DAYBREAK...THEN CONTINUE TO IMPROVE THROUGH LATE WEEK.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS COULD EQUATE
TO REDUCED VISIBILITIES TONIGHT INTO MONDAY. SEA FOG COULD DEVELOP
AS SLIGHTLY WARMER AIR ARRIVES ATOP MID/UPPER 50 SHELF WATER TEMPS
WITHIN A SOUTH AND SOUTHWEST FLOW LATE MONDAY INTO TUESDAY PRIOR
TO WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND
TUESDAY NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 200622
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
122 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AREAS OF SPRINKLES ARE EXPECTED TO INCREASE OVERNIGHT INTO AREAS
OF LIGHT RAIN AS THE LOWER LEVELS MOISTEN WITH TIME. OUR TRENDS
WITH POPS INCREASING TO LIKELY TO CATEGORICAL STILL LOOKS TO WORK
OUT ALTHOUGH QPF AMOUNTS WILL BE LOW-END MANY AREAS. MIDNIGHT
UPDATE INITIALIZED TEMPS MILDER IN SE GEORGIA AND RAISED LOW TEMPS
IN A FEW SPOTS GIVEN THE BLANKET OF CLOUD COVER AND ONGOING
TRENDS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COAST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE
ARRIVAL OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS
SUNDAY...BUT RAMPING UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO
THE CATEGORICAL RANGE. WE DON/T YET HAVE 100 POPS GIVEN SOME MINOR
TIMING ISSUES...BUT FIGURE THAT EVERYONE WILL GET A STEADY RAIN
DEVELOPING AT SOME POINT SUNDAY NIGHT WITH THE LARGE SCALE FORCING
FROM THE SHORT WAVE AND THE RIGHT ENTRANCE REGION OF THE UPPER
JET. WITH PWATS TO CLIMB TO AROUND 1.4 TO 1.5 INCHES WE ANTICIPATE
HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4 INCH RANGE. TEMPS WILL BE
BELOW NORMAL DURING THE DAY...THEN FALL ONLY ABOUT 6-10 DEGREES AT
NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS IS NOT
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE
CONTINUE TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR
MOST AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S
ARE EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD
QUICKLY DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE
AREA LATE TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE
UPPER 40S TO AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THE MAIN FORECAST PROBLEM IS WHEN AND WHERE LOW CLOUDS FILL-IN AFTER
A DEVELOPING SURFACE WAVE OFFSHORE DEPARTS AND A WEDGE INVERSION
CAN SOLIDLY LOCK IN. GIVEN THE LATEST SREF PROGS AND 00Z NAM...IT
MAKE TAKE UNTIL LATER TODAY IN AT KCHS AND THIS EVENING AT KSAV.
WE MADE SOME MINOR ADJUSTMENTS TO THE PREVIOUS TAF CYCLE BUT KEPT
PERSISTENCE OVERALL. MVFR CIGS ARE LIKELY AT KCHS BY THIS AFTERNOON
AND MVFR/IFR TONIGHT. AT KSAV...MVFR CIGS POSSIBLE AFTER SUNRISE
THEN CONFIDENCE INCREASES IN MVFR GOING IFR TONIGHT AS THE INVERSION
STRENGTHENS.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
TONIGHT...A TIGHTENING PRESSURE GRADIENT SHOULD TRANSLATE TO MORE
UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE TO 10-15 KT
OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. ACCORDINGLY...
SEAS SHOULD BUILD TO 2-3 FT LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 200622
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
122 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AREAS OF SPRINKLES ARE EXPECTED TO INCREASE OVERNIGHT INTO AREAS
OF LIGHT RAIN AS THE LOWER LEVELS MOISTEN WITH TIME. OUR TRENDS
WITH POPS INCREASING TO LIKELY TO CATEGORICAL STILL LOOKS TO WORK
OUT ALTHOUGH QPF AMOUNTS WILL BE LOW-END MANY AREAS. MIDNIGHT
UPDATE INITIALIZED TEMPS MILDER IN SE GEORGIA AND RAISED LOW TEMPS
IN A FEW SPOTS GIVEN THE BLANKET OF CLOUD COVER AND ONGOING
TRENDS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COAST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE
ARRIVAL OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS
SUNDAY...BUT RAMPING UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO
THE CATEGORICAL RANGE. WE DON/T YET HAVE 100 POPS GIVEN SOME MINOR
TIMING ISSUES...BUT FIGURE THAT EVERYONE WILL GET A STEADY RAIN
DEVELOPING AT SOME POINT SUNDAY NIGHT WITH THE LARGE SCALE FORCING
FROM THE SHORT WAVE AND THE RIGHT ENTRANCE REGION OF THE UPPER
JET. WITH PWATS TO CLIMB TO AROUND 1.4 TO 1.5 INCHES WE ANTICIPATE
HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4 INCH RANGE. TEMPS WILL BE
BELOW NORMAL DURING THE DAY...THEN FALL ONLY ABOUT 6-10 DEGREES AT
NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS IS NOT
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE
CONTINUE TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR
MOST AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S
ARE EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD
QUICKLY DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE
AREA LATE TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE
UPPER 40S TO AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THE MAIN FORECAST PROBLEM IS WHEN AND WHERE LOW CLOUDS FILL-IN AFTER
A DEVELOPING SURFACE WAVE OFFSHORE DEPARTS AND A WEDGE INVERSION
CAN SOLIDLY LOCK IN. GIVEN THE LATEST SREF PROGS AND 00Z NAM...IT
MAKE TAKE UNTIL LATER TODAY IN AT KCHS AND THIS EVENING AT KSAV.
WE MADE SOME MINOR ADJUSTMENTS TO THE PREVIOUS TAF CYCLE BUT KEPT
PERSISTENCE OVERALL. MVFR CIGS ARE LIKELY AT KCHS BY THIS AFTERNOON
AND MVFR/IFR TONIGHT. AT KSAV...MVFR CIGS POSSIBLE AFTER SUNRISE
THEN CONFIDENCE INCREASES IN MVFR GOING IFR TONIGHT AS THE INVERSION
STRENGTHENS.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
TONIGHT...A TIGHTENING PRESSURE GRADIENT SHOULD TRANSLATE TO MORE
UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE TO 10-15 KT
OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. ACCORDINGLY...
SEAS SHOULD BUILD TO 2-3 FT LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...







000
FXUS62 KCHS 200458
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1158 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WEAK CYCLOGENESIS IS ONGOING OFF THE SOUTHWEST LOUISIANA COAST
THIS EVENING WITH SUPPORT FROM THE RIGHT ENTRANCE REGION OF THE
SUBTROPICAL JET AND SUBTLE SHORTWAVE ENERGY MOVING ACROSS
NORTHEAST TEXAS. THESE FEATURES WILL GRADUALLY TRANSLATE EAST
TONIGHT WITH SECONDARY CYCLOGENESIS INITIATING OFF THE SOUTHEAST
U.S. COAST NEAR THE WESTERN WALL OF THE GULF STREAM BY SUNRISE
SATURDAY. FORCING WITH THIS SYSTEM DOES NOT LOOK OVERLY IMPRESSIVE
IN THE VARIOUS MODEL MASS FIELDS WITH ONLY MODEST ISENTROPIC
ASSENT NOTED ALONG THE 290-305K SURFACES. SOUTHWEST FLOW AHEAD OF
THIS SYSTEM WILL ADVECT GULF MOISTURE NORTHEAST INTO SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA OVERNIGHT WITH MODEL PWAT
PROGS SHOWING PWAT VALUES REACHING AS HIGH AS 1 TO 1.10 INCHES BY
MID-MORNING SATURDAY. LIGHT RAIN IS THEREFORE EXPECTED TO
GRADUALLY OVERSPREAD THE AREA WELL AFTER MIDNIGHT AS NOSE OF
STRONGEST ISENTROPIC ASSENT NUDGES IN FROM THE SOUTHWEST...BUT IT
WILL TAKE SOME TIME FOR THE SUB-CLOUD LAYER TO MOISTEN UP ENOUGH
TO SUPPORT ANYTHING MORE THAN SPRINKLES OR VERY LIGHT RAIN.

HAVE ADJUSTED THE TIMING OF HIGHEST POPS ONCE AGAIN WITH THE LATE
EVENING UPDATE...MAINLY TO DELAY THE ONSET OF CATEGORICAL POPS
UNTIL AFTER 4 AM BASED ON THE LATEST HIGH RESOLUTION DATA. THE
HIGHEST PROBABILITIES FOR MEASURABLE RAINFALL WILL REMAIN CONFINED
TO A CORRIDOR ROUGHLY BOUNDED BY MILLEN-REIDSVILLE-NORTH
CHARLESTON-HARLEYVILLE BOX THROUGH SUNRISE. LOWS WILL RANGE FROM
THE LOWER 40S NORTH AND FAR WEST TO THE MID- UPPER 40S
CENTRAL...SOUTH AND COASTAL AREAS.

CHANGE SUMMARY FOR THE EARLY EVENING UPDATE...
* MODIFIED HOURLY POPS TO BETTER FIX THE EXPECTED EVOLUTION OF
  RAIN OVERNIGHT INTO EARLY SATURDAY MORNING.
* ADJUSTED HOURLY TEMPERATURE AND DEWPOINT GRIDS THROUGH 3 AM
  BASED ON CURRENT OBSERVATIONS AND A 50/50 BLEND OF GLAMP AND RAP
  DATA.
* LOWERED QPF THROUGH 20/12Z SLIGHTLY.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COAST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE
ARRIVAL OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS
SUNDAY...BUT RAMPING UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO
THE CATEGORICAL RANGE. WE DON/T YET HAVE 100 POPS GIVEN SOME MINOR
TIMING ISSUES...BUT FIGURE THAT EVERYONE WILL GET A STEADY RAIN
DEVELOPING AT SOME POINT SUNDAY NIGHT WITH THE LARGE SCALE FORCING
FROM THE SHORT WAVE AND THE RIGHT ENTRANCE REGION OF THE UPPER
JET. WITH PWATS TO CLIMB TO AROUND 1.4 TO 1.5 INCHES WE ANTICIPATE
HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4 INCH RANGE. TEMPS WILL BE
BELOW NORMAL DURING THE DAY...THEN FALL ONLY ABOUT 6-10 DEGREES AT
NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS IS NOT
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE
CONTINUE TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR
MOST AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S
ARE EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD
QUICKLY DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE
AREA LATE TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE
UPPER 40S TO AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THIS EVENING...AND GIVEN
LOW-LEVEL DRY AIR INITIALLY IN PLACE ODDS FAVOR VFR CONDITIONS
PERSISTING THROUGH 12Z. HOWEVER...AS RAIN OVERSPREADS THE
AREA...THE POTENTIAL FOR AT LEAST MVFR CEILINGS WILL INCREASE
AFTER AFTER 09Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR
CEILINGS SHOULD PREVAIL AT KCHS FOR THE BALANCE OF THE 18Z TAF
PERIOD WITH CIGS IMPROVING TO LOW-END VFR AT KSAV. IFR VSBYS/CIGS CAN
NOT BE COMPLETELY RULED OUT WHERE POCKETS OF HEAVIER RAINS
OCCUR...BUT PROBABILITIES ARE TOO LOW TO INCLUDE ANY MENTION ATTM.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
TONIGHT...A TIGHTENING PRESSURE GRADIENT SHOULD TRANSLATE TO MORE
UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE TO 10-15 KT
OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. ACCORDINGLY...
SEAS SHOULD BUILD TO 2-3 FT LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST








000
FXUS62 KCHS 200458
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1158 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WEAK CYCLOGENESIS IS ONGOING OFF THE SOUTHWEST LOUISIANA COAST
THIS EVENING WITH SUPPORT FROM THE RIGHT ENTRANCE REGION OF THE
SUBTROPICAL JET AND SUBTLE SHORTWAVE ENERGY MOVING ACROSS
NORTHEAST TEXAS. THESE FEATURES WILL GRADUALLY TRANSLATE EAST
TONIGHT WITH SECONDARY CYCLOGENESIS INITIATING OFF THE SOUTHEAST
U.S. COAST NEAR THE WESTERN WALL OF THE GULF STREAM BY SUNRISE
SATURDAY. FORCING WITH THIS SYSTEM DOES NOT LOOK OVERLY IMPRESSIVE
IN THE VARIOUS MODEL MASS FIELDS WITH ONLY MODEST ISENTROPIC
ASSENT NOTED ALONG THE 290-305K SURFACES. SOUTHWEST FLOW AHEAD OF
THIS SYSTEM WILL ADVECT GULF MOISTURE NORTHEAST INTO SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA OVERNIGHT WITH MODEL PWAT
PROGS SHOWING PWAT VALUES REACHING AS HIGH AS 1 TO 1.10 INCHES BY
MID-MORNING SATURDAY. LIGHT RAIN IS THEREFORE EXPECTED TO
GRADUALLY OVERSPREAD THE AREA WELL AFTER MIDNIGHT AS NOSE OF
STRONGEST ISENTROPIC ASSENT NUDGES IN FROM THE SOUTHWEST...BUT IT
WILL TAKE SOME TIME FOR THE SUB-CLOUD LAYER TO MOISTEN UP ENOUGH
TO SUPPORT ANYTHING MORE THAN SPRINKLES OR VERY LIGHT RAIN.

HAVE ADJUSTED THE TIMING OF HIGHEST POPS ONCE AGAIN WITH THE LATE
EVENING UPDATE...MAINLY TO DELAY THE ONSET OF CATEGORICAL POPS
UNTIL AFTER 4 AM BASED ON THE LATEST HIGH RESOLUTION DATA. THE
HIGHEST PROBABILITIES FOR MEASURABLE RAINFALL WILL REMAIN CONFINED
TO A CORRIDOR ROUGHLY BOUNDED BY MILLEN-REIDSVILLE-NORTH
CHARLESTON-HARLEYVILLE BOX THROUGH SUNRISE. LOWS WILL RANGE FROM
THE LOWER 40S NORTH AND FAR WEST TO THE MID- UPPER 40S
CENTRAL...SOUTH AND COASTAL AREAS.

CHANGE SUMMARY FOR THE EARLY EVENING UPDATE...
* MODIFIED HOURLY POPS TO BETTER FIX THE EXPECTED EVOLUTION OF
  RAIN OVERNIGHT INTO EARLY SATURDAY MORNING.
* ADJUSTED HOURLY TEMPERATURE AND DEWPOINT GRIDS THROUGH 3 AM
  BASED ON CURRENT OBSERVATIONS AND A 50/50 BLEND OF GLAMP AND RAP
  DATA.
* LOWERED QPF THROUGH 20/12Z SLIGHTLY.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COAST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE
ARRIVAL OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS
SUNDAY...BUT RAMPING UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO
THE CATEGORICAL RANGE. WE DON/T YET HAVE 100 POPS GIVEN SOME MINOR
TIMING ISSUES...BUT FIGURE THAT EVERYONE WILL GET A STEADY RAIN
DEVELOPING AT SOME POINT SUNDAY NIGHT WITH THE LARGE SCALE FORCING
FROM THE SHORT WAVE AND THE RIGHT ENTRANCE REGION OF THE UPPER
JET. WITH PWATS TO CLIMB TO AROUND 1.4 TO 1.5 INCHES WE ANTICIPATE
HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4 INCH RANGE. TEMPS WILL BE
BELOW NORMAL DURING THE DAY...THEN FALL ONLY ABOUT 6-10 DEGREES AT
NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS IS NOT
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE
CONTINUE TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR
MOST AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S
ARE EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD
QUICKLY DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE
AREA LATE TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE
UPPER 40S TO AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THIS EVENING...AND GIVEN
LOW-LEVEL DRY AIR INITIALLY IN PLACE ODDS FAVOR VFR CONDITIONS
PERSISTING THROUGH 12Z. HOWEVER...AS RAIN OVERSPREADS THE
AREA...THE POTENTIAL FOR AT LEAST MVFR CEILINGS WILL INCREASE
AFTER AFTER 09Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR
CEILINGS SHOULD PREVAIL AT KCHS FOR THE BALANCE OF THE 18Z TAF
PERIOD WITH CIGS IMPROVING TO LOW-END VFR AT KSAV. IFR VSBYS/CIGS CAN
NOT BE COMPLETELY RULED OUT WHERE POCKETS OF HEAVIER RAINS
OCCUR...BUT PROBABILITIES ARE TOO LOW TO INCLUDE ANY MENTION ATTM.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
TONIGHT...A TIGHTENING PRESSURE GRADIENT SHOULD TRANSLATE TO MORE
UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE TO 10-15 KT
OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. ACCORDINGLY...
SEAS SHOULD BUILD TO 2-3 FT LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST







000
FXUS62 KCHS 200216
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
916 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WEAK CYCLOGENESIS IS ONGOING OFF THE SOUTHWEST LOUISIANA COAST
THIS EVENING WITH SUPPORT FROM THE RIGHT ENTRANCE REGION OF THE
SUBTROPICAL JET AND SUBTLE SHORTWAVE ENERGY MOVING ACROSS
NORTHEAST TEXAS. THESE FEATURES WILL GRADUALLY TRANSLATE EAST
TONIGHT WITH SECONDARY CYCLOGENESIS INITIATING OFF THE SOUTHEAST
U.S. COAST NEAR THE WESTERN WALL OF THE GULF STREAM BY SUNRISE
SATURDAY. FORCING WITH THIS SYSTEM DOES NOT LOOK OVERLY IMPRESSIVE
IN THE VARIOUS MODEL MASS FIELDS WITH ONLY MODEST ISENTROPIC
ASSENT NOTED ALONG THE 290-305K SURFACES. SOUTHWEST FLOW AHEAD OF
THIS SYSTEM WILL ADVECT GULF MOISTURE NORTHEAST INTO SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA OVERNIGHT WITH MODEL PWAT
PROGS SHOWING PWAT VALUES REACHING AS HIGH AS 1 TO 1.10 INCHES BY
MID-MORNING SATURDAY. LIGHT RAIN IS THEREFORE EXPECTED TO
GRADUALLY OVERSPREAD THE AREA WELL AFTER MIDNIGHT AS NOSE OF
STRONGEST ISENTROPIC ASSENT NUDGES IN FROM THE SOUTHWEST...BUT IT
WILL TAKE SOME TIME FOR THE SUB-CLOUD LAYER TO MOISTEN UP ENOUGH
TO SUPPORT ANYTHING MORE THAN SPRINKLES OR VERY LIGHT RAIN.

HAVE ADJUSTED THE TIMING OF HIGHEST POPS ONCE AGAIN WITH THE LATE
EVENING UPDATE...MAINLY TO DELAY THE ONSET OF CATEGORICAL POPS
UNTIL AFTER 4 AM BASED ON THE LATEST HIGH RESOLUTION DATA. THE
HIGHEST PROBABILITIES FOR MEASURABLE RAINFALL WILL REMAIN CONFINED
TO A CORRIDOR ROUGHLY BOUNDED BY MILLEN-REIDSVILLE-NORTH
CHARLESTON-HARLEYVILLE BOX THROUGH SUNRISE. LOWS WILL RANGE FROM
THE LOWER 40S NORTH AND FAR WEST TO THE MID- UPPER 40S
CENTRAL...SOUTH AND COASTAL AREAS.

CHANGE SUMMARY FOR THE EARLY EVENING UPDATE...
* MODIFIED HOURLY POPS TO BETTER FIX THE EXPECTED EVOLUTION OF
  RAIN OVERNIGHT INTO EARLY SATURDAY MORNING.
* ADJUSTED HOURLY TEMPERATURE AND DEWPOINT GRIDS THROUGH 3 AM
  BASED ON CURRENT OBSERVATIONS AND A 50/50 BLEND OF GLAMP AND RAP
  DATA.
* LOWERED QPF THROUGH 20/12Z SLIGHTLY.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE ARRIVAL
OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS SUNDAY...BUT RAMPING
UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO THE CATEGORICAL RANGE. WE
DON/T YET HAVE 100 POPS GIVEN SOME MINOR TIMING ISSUES...BUT FIGURE
THAT EVERYONE WILL GET A STEADY RAIN DEVELOPING AT SOME POINT SUNDAY
NIGHT WITH THE LARGE SCALE FORCING FROM THE SHORT WAVE AND THE RIGHT
ENTRANCE REGION OF THE UPPER JET. WITH PWATS TO CLIMB TO AROUND 1.4
TO 1.5 INCHES WE ANTICIPATE HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4
INCH RANGE. TEMPS WILL BE BELOW NORMAL DURING THE DAY...THEN FALL
ONLY ABOUT 6-10 DEGREES AT NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS IS NOT
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE
CONTINUE TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THIS EVENING...AND GIVEN
LOW-LEVEL DRY AIR INITIALLY IN PLACE ODDS FAVOR VFR CONDITIONS
PERSISTING THROUGH 12Z. HOWEVER...AS RAIN OVERSPREADS THE
AREA...THE POTENTIAL FOR AT LEAST MVFR CEILINGS WILL INCREASE
AFTER AFTER 09Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR
CEILINGS SHOULD PREVAIL AT KCHS FOR THE BALANCE OF THE 18Z TAF
PERIOD WITH CIGS IMPROVING TO LOW-END VFR AT KSAV. IFR VSBYS/CIGS CAN
NOT BE COMPLETELY RULED OUT WHERE POCKETS OF HEAVIER RAINS
OCCUR...BUT PROBABILITIES ARE TOO LOW TO INCLUDE ANY MENTION ATTM.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
TONIGHT...A TIGHTENING PRESSURE GRADIENT SHOULD TRANSLATE TO MORE
UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE TO 10-15 KT
OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. ACCORDINGLY...
SEAS SHOULD BUILD TO 2-3 FT LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST







000
FXUS62 KCHS 200216
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
916 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WEAK CYCLOGENESIS IS ONGOING OFF THE SOUTHWEST LOUISIANA COAST
THIS EVENING WITH SUPPORT FROM THE RIGHT ENTRANCE REGION OF THE
SUBTROPICAL JET AND SUBTLE SHORTWAVE ENERGY MOVING ACROSS
NORTHEAST TEXAS. THESE FEATURES WILL GRADUALLY TRANSLATE EAST
TONIGHT WITH SECONDARY CYCLOGENESIS INITIATING OFF THE SOUTHEAST
U.S. COAST NEAR THE WESTERN WALL OF THE GULF STREAM BY SUNRISE
SATURDAY. FORCING WITH THIS SYSTEM DOES NOT LOOK OVERLY IMPRESSIVE
IN THE VARIOUS MODEL MASS FIELDS WITH ONLY MODEST ISENTROPIC
ASSENT NOTED ALONG THE 290-305K SURFACES. SOUTHWEST FLOW AHEAD OF
THIS SYSTEM WILL ADVECT GULF MOISTURE NORTHEAST INTO SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA OVERNIGHT WITH MODEL PWAT
PROGS SHOWING PWAT VALUES REACHING AS HIGH AS 1 TO 1.10 INCHES BY
MID-MORNING SATURDAY. LIGHT RAIN IS THEREFORE EXPECTED TO
GRADUALLY OVERSPREAD THE AREA WELL AFTER MIDNIGHT AS NOSE OF
STRONGEST ISENTROPIC ASSENT NUDGES IN FROM THE SOUTHWEST...BUT IT
WILL TAKE SOME TIME FOR THE SUB-CLOUD LAYER TO MOISTEN UP ENOUGH
TO SUPPORT ANYTHING MORE THAN SPRINKLES OR VERY LIGHT RAIN.

HAVE ADJUSTED THE TIMING OF HIGHEST POPS ONCE AGAIN WITH THE LATE
EVENING UPDATE...MAINLY TO DELAY THE ONSET OF CATEGORICAL POPS
UNTIL AFTER 4 AM BASED ON THE LATEST HIGH RESOLUTION DATA. THE
HIGHEST PROBABILITIES FOR MEASURABLE RAINFALL WILL REMAIN CONFINED
TO A CORRIDOR ROUGHLY BOUNDED BY MILLEN-REIDSVILLE-NORTH
CHARLESTON-HARLEYVILLE BOX THROUGH SUNRISE. LOWS WILL RANGE FROM
THE LOWER 40S NORTH AND FAR WEST TO THE MID- UPPER 40S
CENTRAL...SOUTH AND COASTAL AREAS.

CHANGE SUMMARY FOR THE EARLY EVENING UPDATE...
* MODIFIED HOURLY POPS TO BETTER FIX THE EXPECTED EVOLUTION OF
  RAIN OVERNIGHT INTO EARLY SATURDAY MORNING.
* ADJUSTED HOURLY TEMPERATURE AND DEWPOINT GRIDS THROUGH 3 AM
  BASED ON CURRENT OBSERVATIONS AND A 50/50 BLEND OF GLAMP AND RAP
  DATA.
* LOWERED QPF THROUGH 20/12Z SLIGHTLY.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE ARRIVAL
OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS SUNDAY...BUT RAMPING
UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO THE CATEGORICAL RANGE. WE
DON/T YET HAVE 100 POPS GIVEN SOME MINOR TIMING ISSUES...BUT FIGURE
THAT EVERYONE WILL GET A STEADY RAIN DEVELOPING AT SOME POINT SUNDAY
NIGHT WITH THE LARGE SCALE FORCING FROM THE SHORT WAVE AND THE RIGHT
ENTRANCE REGION OF THE UPPER JET. WITH PWATS TO CLIMB TO AROUND 1.4
TO 1.5 INCHES WE ANTICIPATE HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4
INCH RANGE. TEMPS WILL BE BELOW NORMAL DURING THE DAY...THEN FALL
ONLY ABOUT 6-10 DEGREES AT NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS IS NOT
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE
CONTINUE TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THIS EVENING...AND GIVEN
LOW-LEVEL DRY AIR INITIALLY IN PLACE ODDS FAVOR VFR CONDITIONS
PERSISTING THROUGH 12Z. HOWEVER...AS RAIN OVERSPREADS THE
AREA...THE POTENTIAL FOR AT LEAST MVFR CEILINGS WILL INCREASE
AFTER AFTER 09Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR
CEILINGS SHOULD PREVAIL AT KCHS FOR THE BALANCE OF THE 18Z TAF
PERIOD WITH CIGS IMPROVING TO LOW-END VFR AT KSAV. IFR VSBYS/CIGS CAN
NOT BE COMPLETELY RULED OUT WHERE POCKETS OF HEAVIER RAINS
OCCUR...BUT PROBABILITIES ARE TOO LOW TO INCLUDE ANY MENTION ATTM.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
TONIGHT...A TIGHTENING PRESSURE GRADIENT SHOULD TRANSLATE TO MORE
UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE TO 10-15 KT
OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. ACCORDINGLY...
SEAS SHOULD BUILD TO 2-3 FT LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST






000
FXUS62 KCHS 192316
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
616 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WEAK CYCLOGENESIS IS ONGOING EARLY THIS EVENING SOUTH OFF THE COAST
OF SOUTHWEST LOUISIANA WITH SUPPORT FROM THE RIGHT ENTRANCE REGION
OF THE SUBTROPICAL JET AND SUBTLE SHORTWAVE ENERGY MOVING ACROSS
NORTHEAST TEXAS. THESE FEATURES WILL GRADUALLY TRANSLATE EAST
TONIGHT WITH SECONDARY CYCLOGENESIS INITIATING OFF THE SOUTHEAST
U.S. COAST NEAR THE WESTERN WALL OF THE GULF STREAM BY SUNRISE
SATURDAY. FORCING WITH THIS SYSTEM DOES NOT LOOK OVERLY IMPRESSIVE
IN THE VARIOUS MODEL MASS FIELDS WITH ONLY MODEST ISENTROPIC
ASSENT NOTED ALONG THE 290-305K SURFACES. SOUTHWEST FLOW AHEAD OF
THIS SYSTEM WILL ALLOW GULF MOISTURE TO ADVECT NORTHEAST INTO
SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA OVERNIGHT WITH
MODEL PWAT PROGS SHOWING PWAT VALUES REACHING AS HIGH AS 1 TO 1.10
INCHES BY MID-MORNING SATURDAY. LIGHT RAIN IS THEREFORE EXPECTED
TO GRADUALLY OVERSPREAD THE AREA WELL AFTER MIDNIGHT AS NOSE OF
STRONGEST ISENTROPIC ASSENT NUDGES IN FROM THE SOUTHWEST...BUT IT
WILL TAKE SOME TIME FOR THE SUB-CLOUD LAYER TO MOISTEN UP ENOUGH TO
SUPPORT ANYTHING MORE THAN SPRINKLES OR VERY LIGHT RAIN. HAVE
ADJUSTED THE TIMING OF HIGHEST POPS SLIGHTLY WITH THE EARLY
EVENING UPDATE...MAINLY TO DELAY THE ONSET OF CATEGORICAL POPS
UNTIL AFTER 3-4 AM BASED ON THE LATEST HIGH RESOLUTION DATA. THE
HIGHEST PROBABILITIES FOR MEASURABLE RAINFALL WILL REMAIN CONFINED
TO A CORRIDOR ROUGHLY BOUNDED BY A MILLEN-REIDSVILLE-HARLEYVILLE-
NORTH CHARLESTON BOX THROUGH SUNRISE. LOWS WILL RANGE FROM THE
LOWER 40S NORTH AND FAR WEST TO THE MID-UPPER 40S CENTRAL...SOUTH
AND COASTAL AREAS.

CHANGE SUMMARY FOR THE EARLY EVENING UPDATE...
* MODIFIED HOURLY POPS TO BETTER FIX THE EXPECTED EVOLUTION OF
  RAIN OVERNIGHT INTO EARLY SATURDAY MORNING.
* ADJUSTED HOURLY TEMPERATURE AND DEWPOINT GRIDS THROUGH MIDNIGHT
  BASED ON CURRENT OBSERVATIONS AND A 50/50 BLEND OF GLAMP AND RAP
  DATA.
* SLIGHT ADJUSTMENT TO WIND DIRECTIONS AND SPEEDS BASED ON SHORT
  TERM GUIDANCE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE ARRIVAL
OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS SUNDAY...BUT RAMPING
UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO THE CATEGORICAL RANGE. WE
DON/T YET HAVE 100 POPS GIVEN SOME MINOR TIMING ISSUES...BUT FIGURE
THAT EVERYONE WILL GET A STEADY RAIN DEVELOPING AT SOME POINT SUNDAY
NIGHT WITH THE LARGE SCALE FORCING FROM THE SHORT WAVE AND THE RIGHT
ENTRANCE REGION OF THE UPPER JET. WITH PWATS TO CLIMB TO AROUND 1.4
TO 1.5 INCHES WE ANTICIPATE HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4
INCH RANGE. TEMPS WILL BE BELOW NORMAL DURING THE DAY...THEN FALL
ONLY ABOUT 6-10 DEGREES AT NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS IS NOT
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE
CONTINUE TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THIS EVENING...AND GIVEN
LOW-LEVEL DRY AIR INITIALLY IN PLACE ODDS FAVOR VFR CONDITIONS
PERSISTING THROUGH 12Z. HOWEVER...AS RAIN OVERSPREADS THE
AREA...THE POTENTIAL FOR AT LEAST MVFR CEILINGS WILL INCREASE
AFTER AFTER 09Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR
CEILINGS SHOULD PREVAIL AT KCHS FOR THE BALANCE OF THE 18Z TAF
PERIOD WITH CIGS IMPROVING TO LOW-END VFR AT KSAV. IFR VSBYS/CIGS CAN
NOT BE COMPLETELY RULED OUT WHERE POCKETS OF HEAVIER RAINS
OCCUR...BUT PROBABILITIES ARE TOO LOW TO INCLUDE ANY MENTION ATTM.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
TONIGHT...A TIGHTENING PRESSURE GRADIENT SHOULD TRANSLATE TO MORE
UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE TO 10-15 KT
OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. ACCORDINGLY...
SEAS SHOULD BUILD TO 2-3 FT LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST





000
FXUS62 KCHS 192316
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
616 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WEAK CYCLOGENESIS IS ONGOING EARLY THIS EVENING SOUTH OFF THE COAST
OF SOUTHWEST LOUISIANA WITH SUPPORT FROM THE RIGHT ENTRANCE REGION
OF THE SUBTROPICAL JET AND SUBTLE SHORTWAVE ENERGY MOVING ACROSS
NORTHEAST TEXAS. THESE FEATURES WILL GRADUALLY TRANSLATE EAST
TONIGHT WITH SECONDARY CYCLOGENESIS INITIATING OFF THE SOUTHEAST
U.S. COAST NEAR THE WESTERN WALL OF THE GULF STREAM BY SUNRISE
SATURDAY. FORCING WITH THIS SYSTEM DOES NOT LOOK OVERLY IMPRESSIVE
IN THE VARIOUS MODEL MASS FIELDS WITH ONLY MODEST ISENTROPIC
ASSENT NOTED ALONG THE 290-305K SURFACES. SOUTHWEST FLOW AHEAD OF
THIS SYSTEM WILL ALLOW GULF MOISTURE TO ADVECT NORTHEAST INTO
SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA OVERNIGHT WITH
MODEL PWAT PROGS SHOWING PWAT VALUES REACHING AS HIGH AS 1 TO 1.10
INCHES BY MID-MORNING SATURDAY. LIGHT RAIN IS THEREFORE EXPECTED
TO GRADUALLY OVERSPREAD THE AREA WELL AFTER MIDNIGHT AS NOSE OF
STRONGEST ISENTROPIC ASSENT NUDGES IN FROM THE SOUTHWEST...BUT IT
WILL TAKE SOME TIME FOR THE SUB-CLOUD LAYER TO MOISTEN UP ENOUGH TO
SUPPORT ANYTHING MORE THAN SPRINKLES OR VERY LIGHT RAIN. HAVE
ADJUSTED THE TIMING OF HIGHEST POPS SLIGHTLY WITH THE EARLY
EVENING UPDATE...MAINLY TO DELAY THE ONSET OF CATEGORICAL POPS
UNTIL AFTER 3-4 AM BASED ON THE LATEST HIGH RESOLUTION DATA. THE
HIGHEST PROBABILITIES FOR MEASURABLE RAINFALL WILL REMAIN CONFINED
TO A CORRIDOR ROUGHLY BOUNDED BY A MILLEN-REIDSVILLE-HARLEYVILLE-
NORTH CHARLESTON BOX THROUGH SUNRISE. LOWS WILL RANGE FROM THE
LOWER 40S NORTH AND FAR WEST TO THE MID-UPPER 40S CENTRAL...SOUTH
AND COASTAL AREAS.

CHANGE SUMMARY FOR THE EARLY EVENING UPDATE...
* MODIFIED HOURLY POPS TO BETTER FIX THE EXPECTED EVOLUTION OF
  RAIN OVERNIGHT INTO EARLY SATURDAY MORNING.
* ADJUSTED HOURLY TEMPERATURE AND DEWPOINT GRIDS THROUGH MIDNIGHT
  BASED ON CURRENT OBSERVATIONS AND A 50/50 BLEND OF GLAMP AND RAP
  DATA.
* SLIGHT ADJUSTMENT TO WIND DIRECTIONS AND SPEEDS BASED ON SHORT
  TERM GUIDANCE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE ARRIVAL
OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS SUNDAY...BUT RAMPING
UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO THE CATEGORICAL RANGE. WE
DON/T YET HAVE 100 POPS GIVEN SOME MINOR TIMING ISSUES...BUT FIGURE
THAT EVERYONE WILL GET A STEADY RAIN DEVELOPING AT SOME POINT SUNDAY
NIGHT WITH THE LARGE SCALE FORCING FROM THE SHORT WAVE AND THE RIGHT
ENTRANCE REGION OF THE UPPER JET. WITH PWATS TO CLIMB TO AROUND 1.4
TO 1.5 INCHES WE ANTICIPATE HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4
INCH RANGE. TEMPS WILL BE BELOW NORMAL DURING THE DAY...THEN FALL
ONLY ABOUT 6-10 DEGREES AT NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS IS NOT
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE
CONTINUE TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THIS EVENING...AND GIVEN
LOW-LEVEL DRY AIR INITIALLY IN PLACE ODDS FAVOR VFR CONDITIONS
PERSISTING THROUGH 12Z. HOWEVER...AS RAIN OVERSPREADS THE
AREA...THE POTENTIAL FOR AT LEAST MVFR CEILINGS WILL INCREASE
AFTER AFTER 09Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR
CEILINGS SHOULD PREVAIL AT KCHS FOR THE BALANCE OF THE 18Z TAF
PERIOD WITH CIGS IMPROVING TO LOW-END VFR AT KSAV. IFR VSBYS/CIGS CAN
NOT BE COMPLETELY RULED OUT WHERE POCKETS OF HEAVIER RAINS
OCCUR...BUT PROBABILITIES ARE TOO LOW TO INCLUDE ANY MENTION ATTM.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
TONIGHT...A TIGHTENING PRESSURE GRADIENT SHOULD TRANSLATE TO MORE
UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE TO 10-15 KT
OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS OFFSHORE. ACCORDINGLY...
SEAS SHOULD BUILD TO 2-3 FT LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO TIDES...
GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS AT
LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST






000
FXUS62 KCHS 192052
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
352 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A SHORT-LIVED PERIOD OF MOSTLY CLEAR TO PARTLY CLOUDY SKIES WILL
SUPPORT DECENT RADIATIONAL COOLING EARLY. THEN...CLOUD COVER WILL
INCREASE/THICKEN AS UPSTREAM MOISTURE STREAMS INTO THE REGION.
A SHORTWAVE TROUGH APPROACHING THE LOWER MS RIVER VALLEY LATE
FRIDAY AFTERNOON WILL ADVANCE E/NE AND WILL CROSS THE SOUTHERN
APPALACHIANS OVERNIGHT. AHEAD OF THIS SYSTEM...RAIN SUPPORTED BY
FOCUSED/DEEP-LAYERED MOISTURE TRANSPORT AS DEPICTED BY PWATS
INCREASING TO AROUND 1 INCH...ISENTROPIC ASCENT AND UPPER LEVEL
DIVERGENCE WILL OVERSPREAD THE REGION FROM W/SW TO E/NE. PRIMARY
FORECAST UNCERTAINTY CENTERS ON TIMING AND LOCATION OF THE ONSET
OF THE RAIN. DRY AIR IN PLACE COULD INITIALLY DELAY THE ONSET OF
RAIN UNTIL LATER THIS EVENING...AND HIGH RESOLUTION GUIDANCE
SUGGESTS THAT RAIN COULD INITIALLY SPREAD ACROSS SOUTHERN COUNTIES
ALONG/SOUTH OF I-16 AND ADJACENT COASTAL WATERS BEFORE SPREADING
INTO AREAS FARTHER NORTH. GIVEN HIGH RES GUIDANCE AND UPSTREAM
RADAR TRENDS INDICATED THE EARLIEST ONSET OF HIGH CHANCE/LIKELY
FOR THESE SOUTHERN AREAS LATE THIS EVENING. EVENTUALLY...WIDESPREAD
RAIN/CATEGORICAL POPS ARE EXPECTED OVERNIGHT. BEST COVERAGE OF
RAIN COULD SHIFT FARTHER NORTH...THUS OVERNIGHT POPS ARE GRADUATED
FROM CATEGORICAL CENTRAL/NORTH TO CHANCE FAR SOUTH. HOWEVER...HIGHER
POPS COULD EVENTUALLY BE REQUIRED EVEN ACROSS FAR SOUTHERN
COUNTIES. BY EARLY SATURDAY MORNING...ONE TO TWO TENTHS OF AN INCH OF
RAIN COULD FALL IN MANY AREAS...WITH LOCALLY GREATER AMOUNTS
POSSIBLE NORTH AND LESSER AMOUNTS POSSIBLE FAR SOUTH.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE ARRIVAL
OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS SUNDAY...BUT RAMPING
UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO THE CATEGORICAL RANGE. WE
DON/T YET HAVE 100 POPS GIVEN SOME MINOR TIMING ISSUES...BUT FIGURE
THAT EVERYONE WILL GET A STEADY RAIN DEVELOPING AT SOME POINT SUNDAY
NIGHT WITH THE LARGE SCALE FORCING FROM THE SHORT WAVE AND THE RIGHT
ENTRANCE REGION OF THE UPPER JET. WITH PWATS TO CLIMB TO AROUND 1.4
TO 1.5 INCHES WE ANTICIPATE HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4
INCH RANGE. TEMPS WILL BE BELOW NORMAL DURING THE DAY...THEN FALL
ONLY ABOUT 6-10 DEGREES AT NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS ISN/T
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE CONTINUE
TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THIS EVENING...AND GIVEN
LOW-LEVEL DRY AIR INITIALLY IN PLACE ODDS FAVOR VFR CONDITIONS
PERSISTING THROUGH 12Z. HOWEVER...AS RAIN OVERSPREADS THE
AREA...THE POTENTIAL FOR AT LEAST MVFR CEILINGS WILL INCREASE
AFTER 06Z- 09Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR
CEILINGS SHOULD PREVAIL FOR THE BALANCE OF THE 18Z TAF
PERIOD...AND AT LEAST OCCASIONAL IFR CEILINGS/MVFR VISIBILITIES
CANNOT BE RULED OUT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
A WEAK PRESSURE PATTERN WILL MAINTAIN VARIABLE WINDS 10 KT OR
LESS INCLUDING AN EARLY SEA BREEZE CIRCULATION AND SEAS AROUND 1
FOOT INTO THIS EVENING. A TIGHTENING PRESSURE GRADIENT SHOULD
TRANSLATE TO MORE UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE
TO 10-15 KT OVERNIGHT. ACCORDINGLY...SEAS SHOULD BUILD TO 2-3 FT
LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO
TIDES...GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS
AT LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...DPB
AVIATION...33/SPR
MARINE...33/SPR
TIDES/COASTAL FLOODING...33








000
FXUS62 KCHS 192052
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
352 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH THIS EVENING. UNSETTLED
WEATHER IS EXPECTED LATER TONIGHT THROUGH MONDAY NIGHT AS SEVERAL
DISTURBANCES MOVE OVER THE REGION. A STRONG COLD FRONT WILL
APPROACH TUESDAY NIGHT AND SHIFT THROUGH THE AREA WEDNESDAY...WITH
DRIER CONDITIONS TO FOLLOW THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A SHORT-LIVED PERIOD OF MOSTLY CLEAR TO PARTLY CLOUDY SKIES WILL
SUPPORT DECENT RADIATIONAL COOLING EARLY. THEN...CLOUD COVER WILL
INCREASE/THICKEN AS UPSTREAM MOISTURE STREAMS INTO THE REGION.
A SHORTWAVE TROUGH APPROACHING THE LOWER MS RIVER VALLEY LATE
FRIDAY AFTERNOON WILL ADVANCE E/NE AND WILL CROSS THE SOUTHERN
APPALACHIANS OVERNIGHT. AHEAD OF THIS SYSTEM...RAIN SUPPORTED BY
FOCUSED/DEEP-LAYERED MOISTURE TRANSPORT AS DEPICTED BY PWATS
INCREASING TO AROUND 1 INCH...ISENTROPIC ASCENT AND UPPER LEVEL
DIVERGENCE WILL OVERSPREAD THE REGION FROM W/SW TO E/NE. PRIMARY
FORECAST UNCERTAINTY CENTERS ON TIMING AND LOCATION OF THE ONSET
OF THE RAIN. DRY AIR IN PLACE COULD INITIALLY DELAY THE ONSET OF
RAIN UNTIL LATER THIS EVENING...AND HIGH RESOLUTION GUIDANCE
SUGGESTS THAT RAIN COULD INITIALLY SPREAD ACROSS SOUTHERN COUNTIES
ALONG/SOUTH OF I-16 AND ADJACENT COASTAL WATERS BEFORE SPREADING
INTO AREAS FARTHER NORTH. GIVEN HIGH RES GUIDANCE AND UPSTREAM
RADAR TRENDS INDICATED THE EARLIEST ONSET OF HIGH CHANCE/LIKELY
FOR THESE SOUTHERN AREAS LATE THIS EVENING. EVENTUALLY...WIDESPREAD
RAIN/CATEGORICAL POPS ARE EXPECTED OVERNIGHT. BEST COVERAGE OF
RAIN COULD SHIFT FARTHER NORTH...THUS OVERNIGHT POPS ARE GRADUATED
FROM CATEGORICAL CENTRAL/NORTH TO CHANCE FAR SOUTH. HOWEVER...HIGHER
POPS COULD EVENTUALLY BE REQUIRED EVEN ACROSS FAR SOUTHERN
COUNTIES. BY EARLY SATURDAY MORNING...ONE TO TWO TENTHS OF AN INCH OF
RAIN COULD FALL IN MANY AREAS...WITH LOCALLY GREATER AMOUNTS
POSSIBLE NORTH AND LESSER AMOUNTS POSSIBLE FAR SOUTH.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...CONDITIONS WILL BE UNSETTLED AND COOLER THAN TODAY IN
RESPONSE TO ISENTROPIC ASCENT THAT LIFTS MOISTURE OVER A SHALLOW
HIGH PRESSURE WEDGE AND A STALLED FRONT OVER THE ATLANTIC TO THE SE.
THAT ALONG WITH AN EMBEDDED SHORT WAVE WITHIN THE FAST MOVING
WESTERLY FLOW ALOFT THAT WILL MOVE THROUGH THE TN VALLEY
TONIGHT...AND AN ELONGATED 125 KT UPPER JET THAT STRETCHES FROM OFF
THE MID ATLANTIC COAST TO TEXAS WILL PROVIDE ADDITIONAL FORCING FOR
ASCENT. THERE IS STILL A LITTLE DRY AIR IN THE LOWER LEVELS AT THE
START OF THE PERIOD...BUT IT WON/T MATTER AS THE VERTICAL COLUMN
BECOMES QUICKLY SATURATED INTO THE MID LEVELS. LIGHT RAINS WILL BE
ONGOING ACROSS MUCH OF THE FORECAST AREA AT DAYBREAK...AND WILL
BECOME MODERATE AT TIMES ACROSS OUR CENTRAL AND NORTHERN ZONES IN
CLOSER PROXIMITY TO THE DYNAMICS ALOFT. WE MIGHT FIND AN EVEN
SHARPER GRADIENT IN REGARDS TO PRECIP THAN WE ARE NOT
FORECASTING...BUT FIGURE ON NEAR 100 PERCENT POPS OVER MOST OF SC
AND IN MOST COMMUNITIES NORTH OF I-16 IN SE GA. POPS THEN TAPER TO
40-50 PERCENT OVER MCINTOSH COUNTY. AS THE SHORT WAVE MOVES EAST
TOWARD THE ATLANTIC BY LATE IN THE DAY OUR RAIN CHANCES WILL DWINDLE
FROM SW/WEST TO EAST/NE...WITH THE BULK OF THE RAIN OFFSHORE BY
NIGHTFALL. DUE TO THE PROGRESSIVE NATURE OF THE RAIN AND THE BULK OF
THE INFLUX OF MOISTURE FROM OFF THE ATLANTIC...OUR QPF IS NO MORE
THAN ABOUT 1/10 TO 2/10 OF AN INCH. COOL AIR WITHIN THE INLAND WEDGE
WILL LIMIT TEMPS TO THE LOWER AND MIDDLE 50S NORTH OF I-16 IN
GA...WITH UPPER 50S TO MAYBE NEAR 60 CLOSER TO THE ALTAMAHA RIVER
BASIN.

SATURDAY NIGHT...THE HIGH PRESSURE WEDGE HOLDS FIRMLY IN PLACE WITH
A WAVE OF LOW PRESSURE ON A STATIONARY FRONT TO THE EAST/SE OF THE
GULF STREAM. HE LACK OF FORCING UPSTAIRS WILL ALLOW FOR MUCH OF THE
RAIN TO HAVE ENDED...BUT SOUNDINGS SHOW A SHARP INVERSION OFF THE
DECK THAT WILL HOLD IN PLACE. THIS WILL RESULT IN AT LEAST A LITTLE
LIGHT RAIN OR MORE LIKELY DRIZZLE. DEPENDING UPON HOW LONG THE BUILD
DOWN OF STRATUS TRANSPIRES WE COULD SEE SOME FOG CONCERNS. LIMITED
COOL ADVECTION AND WIDESPREAD CLOUD COVER WILL PREVENT MUCH OF A
DROP IN TEMPS...AT BEST ABOUT A 10 DEGREE DIURNAL SWING.

SUNDAY AND SUNDAY NIGHT...ANOTHER SOUTHERN SHORT WAVE FEATURE WILL
ARRIVE FROM THE SW LATE IN THE DAY OR AT NIGHT. THIS WILL TRIGGER
ANOTHER WAVE OF LOW PRESSURE ALONG THE BAROCLINIC ZONE TO OUR
EAST/SE...WHILE THE INLAND WEDGE REMAINS ANCHORED IN PLACE. BUT AS
THE FLOW ALOFT BACKS MORE SW IT PULLS THIS FEATURE A LITTLE CLOSER
TO THE COST AND ALSO OPENS UP THE GULF ALOFT FOR IT/S FEED OF
MOISTURE. WE DON/T HAVE TOO MUCH COVERAGE OF RAIN UNTIL THE ARRIVAL
OF THIS SHORT WAVE...SHOWING MAINLY 20-30 POPS SUNDAY...BUT RAMPING
UP QUICKLY FROM SW TO NE SUNDAY NIGHT INTO THE CATEGORICAL RANGE. WE
DON/T YET HAVE 100 POPS GIVEN SOME MINOR TIMING ISSUES...BUT FIGURE
THAT EVERYONE WILL GET A STEADY RAIN DEVELOPING AT SOME POINT SUNDAY
NIGHT WITH THE LARGE SCALE FORCING FROM THE SHORT WAVE AND THE RIGHT
ENTRANCE REGION OF THE UPPER JET. WITH PWATS TO CLIMB TO AROUND 1.4
TO 1.5 INCHES WE ANTICIPATE HIGHER PRECIP AMOUNTS IN THE 1/2 TO 3/4
INCH RANGE. TEMPS WILL BE BELOW NORMAL DURING THE DAY...THEN FALL
ONLY ABOUT 6-10 DEGREES AT NIGHT.

MONDAY...WE/RE STILL STUCK WITHIN THE COOL AIR WEDGE REGIME WITH ANY
COASTAL WARM FRONT TO REMAIN OUT NEAR THE GULF STREAM. THERE IS
STILL ENOUGH FORCING IN RESPONSE TO THE PROXIMITY TO THE WARM
FRONT...THE TAIL OF THE MID LEVEL SHORT WAVE AND NEARBY UPPER
JET...PLUS ISENTROPIC UPGLIDE PERSISTS. PWATS ACTUALLY MAKE A RUN
FOR ALMOST 2 STANDARD DEVIATIONS ABOVE NORMAL...SO WE/RE STILL
SHOWING 80-90 PERCENT RAIN CHANCES. THERE IS AT LEAST A LITTLE
ELEVATED INSTABILITY...WITH DECENT MID LEVEL LAPSE RATES AND
SHOWALTER INDICES APPROACHING ZERO. BUT CERTAINLY NOT ENOUGH TO
JUSTIFY ADDING MENTION OF THUNDER TO THE GRIDDED ELEMENTS.
ADDITIONAL QPF OF 1/2 TO 2/3 INCHES. MY CONFIDENCE ON TEMPS ISN/T
THE GREATEST...BUT WITH COOL AIR DAMMING STILL IN PLACE WE CONTINUE
TO SHOW BELOW NORMAL TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THIS EVENING...AND GIVEN
LOW-LEVEL DRY AIR INITIALLY IN PLACE ODDS FAVOR VFR CONDITIONS
PERSISTING THROUGH 12Z. HOWEVER...AS RAIN OVERSPREADS THE
AREA...THE POTENTIAL FOR AT LEAST MVFR CEILINGS WILL INCREASE
AFTER 06Z- 09Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR
CEILINGS SHOULD PREVAIL FOR THE BALANCE OF THE 18Z TAF
PERIOD...AND AT LEAST OCCASIONAL IFR CEILINGS/MVFR VISIBILITIES
CANNOT BE RULED OUT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS AND LOW STRATUS SATURDAY AFTERNOON
THROUGH MONDAY NIGHT WHILE A WEDGE OF HIGH PRESSURE PERSISTS INLAND
AND WAVES OF LOW PRESSURE LIFT NE ACROSS THE NEARBY ATLANTIC.
ADDITIONAL FLIGHT RESTRICTIONS LIKELY TUESDAY INTO EARLY WEDNESDAY
AS A STRONG COLD FRONT APPROACHES FROM THE WEST...ACCOMPANIED BY
SHRA AND POSSIBLE TSRA. WINDY WEATHER BEHIND THE FRONT WEDNESDAY.

&&

.MARINE...
A WEAK PRESSURE PATTERN WILL MAINTAIN VARIABLE WINDS 10 KT OR
LESS INCLUDING AN EARLY SEA BREEZE CIRCULATION AND SEAS AROUND 1
FOOT INTO THIS EVENING. A TIGHTENING PRESSURE GRADIENT SHOULD
TRANSLATE TO MORE UNIFORM N/NE WINDS WHICH ARE EXPECTED TO INCREASE
TO 10-15 KT OVERNIGHT. ACCORDINGLY...SEAS SHOULD BUILD TO 2-3 FT
LATE.

SATURDAY AND SATURDAY NIGHT...A WAVE OF LOW PRESSURE WILL FORM ALONG
A STALLED OUT FRONT TO THE EAST/SE OF THE LOCAL WATERS...WHILE AN
INLAND WEDGE OF HIGH PRESSURE HOLDS IN PLACE. THERE IS AT LEAST SOME
PINCHING OF THE PRESSURE GRADIENT TO GENERATE NORTH OR NE WINDS AS
HIGH AS 15 OR 20 KT. THE RESULTING SEAS WILL PEAK AT 3 OR 4 FT. SO
FOR NOW WE DON/T ANTICIPATE ANY SMALL CRAFT ADVISORY HEADLINES.

SUNDAY THROUGH MONDAY...THE FIRST WAVE OF LOW PRESSURE PULLS AWAY OR
DISSIPATES...BUT A SECOND WAVE OF WILL TAKE SHAPE IN SIMILAR
POSITION TO THE EAST/SE OF THE MARINE AREA. AS THE FLOW ALOFT BACKS
TO THE SW WILL ATTEMPT TO DRAW THE SURFACE WAVE AND ASSOCIATED WARM
FRONT BACK CLOSER TO THE COAST BY LATE IN THE PERIOD. BUT INLAND
WEDGE IS RELUCTANT TO RELAX ITS GRIP ACROSS THE SE...SO ANY VEERING
OF WINDS FROM THE NE AROUND TO THE SE OR SOUTH WILL TAKE SOME
TIME...IF AT ALL DURING THIS PERIOD. WINDS WILL AGAIN PEAK AT 15 OR
20 KT PENDING THE EXACT EVOLUTION OF THE PATTERN...WITH SEAS AGAIN
NO MORE THAN 3 OR 4 FT. THERE COULD BE A LITTLE THUNDER AND
LIGHTNING OUT NEAR THE GULF STREAM SUNDAY NIGHT INTO MONDAY...IN
CLOSE PROXIMITY TO THE COASTAL WARM FRONT.

TUESDAY AND WEDNESDAY...THE COASTAL WARM FRONT LIFTS NORTH OF THE
AREA TUESDAY AND GIVES WAY TO A STRONG COLD FRONT EARLY WEDNESDAY.
MARINE LAYERING EFFECTS WITHIN THE WARM ADVECTION REGIME WILL LIKELY
HOLD WINDS BELOW ANY SMALL CRAFT THRESHOLDS...BUT STEADY ISALLOBARIC
PRESSURE RISES AND COLD ADVECTION BEHIND THE FRONT WILL LEAD TO AT
LEAST SMALL CRAFT ADVISORIES OR MAYBE GALES. NOT YET SURE HOW THE
SITUATION WILL UNFOLD...BUT THERE IS AT LEAST A LOW END RISK OF SOME
STRONG OR SEVERE T-STORMS.

SEA FOG...MARINERS ARE ADVISED THAT LOW STRATUS DECKS AND PERIODS OF
RAIN OR DRIZZLE COULD EQUATE TO REDUCED VISIBILITIES SATURDAY INTO
MONDAY. THEN AS SLIGHTLY WARMER AIR ARRIVES ATOP THE MID AND UPPER
50S SHELF WATERS WITHIN A SOUTH AND SW FLOW LATE MONDAY NIGHT AND
TUESDAY...THIS MAY ALLOW FOR THE DEVELOPMENT OF SEA FOG PRIOR TO
WINDS INCREASING ENOUGH TO SCOUR IT OUT LATER TUESDAY AND TUESDAY
NIGHT.

&&

.TIDES/COASTAL FLOODING...
ALTHOUGH THERE ARE NO IMMEDIATE CONCERNS IN REGARDS TO
TIDES...GIVEN THE PERIGEAN SPRING TIDES EARLY NEXT WEEK...THERE IS
AT LEAST A MODERATE RISK OF SHALLOW COASTAL FLOODING CONCERNS MONDAY
AND TUESDAY AROUND THE TIME OF THE MORNING HIGH TIDE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...DPB
AVIATION...33/SPR
MARINE...33/SPR
TIDES/COASTAL FLOODING...33







000
FXUS62 KCHS 191745
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1245 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THIS AFTERNOON AND THIS EVENING.
UNSETTLED WEATHER IS EXPECTED LATER TONIGHT THROUGH TUESDAY NIGHT
AS SEVERAL DISTURBANCES SHIFT OVER THE REGION. A STRONG COLD FRONT
WILL EVENTUALLY SHIFT THROUGH THE AREA WEDNESDAY WITH DRYER
CONDITIONS TO FOLLOW THROUGH LATE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY FRIDAY AFTERNOON...SATELLITE IMAGERY DEPICTED A GRADUAL
DIMINISHING COVERAGE TREND OF MID/HIGH LEVEL CLOUDS CROSSING THE
AREA. THUS FAR...CLOUDS HAVE LIMITED TEMPERATURE RECOVERY...BUT A
GENERAL INCREASE IN INSOLATION SHOULD STILL ALLOW TEMPS TO PUSH
INTO THE LOWER TO MID 60S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR THROUGH 12Z. AS RAIN OVERSPREADS THE AREA...THE POTENTIAL FOR
AT LEAST MVFR CEILINGS WILL INCREASE AFTER 06Z-09Z...BUT GIVEN
LOW-LEVEL DRY AIR IN PLACE OPTED TO DELAY FLIGHT RESTRICTIONS
UNTIL AFTER 12Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR CEILINGS
SHOULD PREVAIL FOR THE BALANCE OF THE 18Z TAF PERIOD...AND AT
LEAST OCCASIONAL IFR CEILINGS/MVFR VISIBILITIES CANNOT BE RULED
OUT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
A WEAK PRESSURE PATTERN WILL MAINTAIN N/NE WINDS AND SEAS AROUND 1
FOOT THIS AFTERNOON THROUGH THIS EVENING. THEN...A TIGHTENING
PRESSURE GRADIENT SHOULD TRANSLATE TO NE WINDS INCREASING TO 10-15
KT OVERNIGHT...ACCOMPANIED BY SEAS BUILDING TO 2-3 FT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...SPR
MARINE...DPB/SPR








000
FXUS62 KCHS 191745
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1245 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THIS AFTERNOON AND THIS EVENING.
UNSETTLED WEATHER IS EXPECTED LATER TONIGHT THROUGH TUESDAY NIGHT
AS SEVERAL DISTURBANCES SHIFT OVER THE REGION. A STRONG COLD FRONT
WILL EVENTUALLY SHIFT THROUGH THE AREA WEDNESDAY WITH DRYER
CONDITIONS TO FOLLOW THROUGH LATE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY FRIDAY AFTERNOON...SATELLITE IMAGERY DEPICTED A GRADUAL
DIMINISHING COVERAGE TREND OF MID/HIGH LEVEL CLOUDS CROSSING THE
AREA. THUS FAR...CLOUDS HAVE LIMITED TEMPERATURE RECOVERY...BUT A
GENERAL INCREASE IN INSOLATION SHOULD STILL ALLOW TEMPS TO PUSH
INTO THE LOWER TO MID 60S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR THROUGH 12Z. AS RAIN OVERSPREADS THE AREA...THE POTENTIAL FOR
AT LEAST MVFR CEILINGS WILL INCREASE AFTER 06Z-09Z...BUT GIVEN
LOW-LEVEL DRY AIR IN PLACE OPTED TO DELAY FLIGHT RESTRICTIONS
UNTIL AFTER 12Z. ONCE CEILINGS LOWER SATURDAY MORNING...MVFR CEILINGS
SHOULD PREVAIL FOR THE BALANCE OF THE 18Z TAF PERIOD...AND AT
LEAST OCCASIONAL IFR CEILINGS/MVFR VISIBILITIES CANNOT BE RULED
OUT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
A WEAK PRESSURE PATTERN WILL MAINTAIN N/NE WINDS AND SEAS AROUND 1
FOOT THIS AFTERNOON THROUGH THIS EVENING. THEN...A TIGHTENING
PRESSURE GRADIENT SHOULD TRANSLATE TO NE WINDS INCREASING TO 10-15
KT OVERNIGHT...ACCOMPANIED BY SEAS BUILDING TO 2-3 FT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...SPR
MARINE...DPB/SPR







000
FXUS62 KCHS 191442
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
942 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. UNSETTLED WEATHER IS EXPECTED
LATER TONIGHT THROUGH TUESDAY NIGHT AS SEVERAL DISTURBANCES SHIFT
OVER THE REGION. A STRONG COLD FRONT WILL EVENTUALLY SHIFT
THROUGH THE AREA WEDNESDAY WITH DRYER CONDITIONS TO FOLLOW
THROUGH LATE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FRIDAY MORNING...SATELLITE IMAGERY SUGGESTED THAT MID/HIGH LEVEL
CLOUDS DEVELOPING WITHIN ISENTROPIC ASCENT REGIME ENHANCED BY A
SHORTWAVE CROSSING TX WILL CONTINUE TO STREAM ACROSS THE REGION
FROM W/SW TO E/NE TODAY...PRODUCING PARTLY SUNNY/MOSTLY CLOUDY
SKIES. ADJUSTED SKY COVER ACCORDINGLY. CLOUD COVER COULD TRANSLATE
TO SLIGHTLY COOLER THAN EXPECTED TEMPERATURES...BUT GIVEN THE
POTENTIAL FOR MID/HIGH CLOUDS THINNING FOR AT LEAST BREAKS OF
SUNSHINE MAINTAINED HIGHS IN THE LOWER TO MID 60S...WARMEST NEAR
THE ALTAMAHA RIVER. OTHERWISE...FORECAST PARAMETERS REMAIN ON
TRACK AND REQUIRED LITTLE/NO ADJUSTMENT WITHIN THE MORNING UPDATE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
VFR AT KSAV AND KCHS LIKELY THROUGH 12Z SATURDAY. CIGS SHOULD
BEGIN TO LOWER AFTER MIDNIGHT BUT LATEST FORECAST SOUNDINGS
SUGGEST CIGS REMAIN VFR UNTIL 12Z SATURDAY ALTHOUGH SOME LOWER
CLOUDS ARE CERTAINLY POSSIBLE IF RAINS DEVELOP EVEN SOONER THAN
EXPECTED. AS OF THE 12Z CYCLE...THESE RAINS ARE EXPECTED TO BREAK
OUT AFTER MIDNIGHT ACROSS THE COASTAL CORRIDOR BUT MAINLY REMAIN
RELATIVELY LIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
ANOTHER DAY OF LIGHT WINDS AND FLAT SEAS PRIOR TO SOME SLOWLY
BUILDING NE FLOW TONIGHT AS A SECONDARY LOW PRES WAVE DEVELOPS
ALONG THE WEST WALL OF THE GULF STREAM EARLY SATURDAY MORNING.
WINDS WILL REMAIN MAINLY 10 KT OR LESS THROUGH THIS EVENING...THEN WE
WILL SEE NE WINDS INCREASE CLOSER TO 15 KT BY 12Z SATURDAY OFF THE
CHARLESTON COUNTY COAST BUT LESSER SPEEDS FURTHER SOUTHWARD GIVEN
THE ANGLE OF THE DEVELOPING PINCHING GRADIENTS. SEAS LESS THAN 2
FT SEAS MOST OF TODAY WILL BUILD TO 2-3 FT TONIGHT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...SPR
MARINE...DPB/SPR







000
FXUS62 KCHS 191442
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
942 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. UNSETTLED WEATHER IS EXPECTED
LATER TONIGHT THROUGH TUESDAY NIGHT AS SEVERAL DISTURBANCES SHIFT
OVER THE REGION. A STRONG COLD FRONT WILL EVENTUALLY SHIFT
THROUGH THE AREA WEDNESDAY WITH DRYER CONDITIONS TO FOLLOW
THROUGH LATE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FRIDAY MORNING...SATELLITE IMAGERY SUGGESTED THAT MID/HIGH LEVEL
CLOUDS DEVELOPING WITHIN ISENTROPIC ASCENT REGIME ENHANCED BY A
SHORTWAVE CROSSING TX WILL CONTINUE TO STREAM ACROSS THE REGION
FROM W/SW TO E/NE TODAY...PRODUCING PARTLY SUNNY/MOSTLY CLOUDY
SKIES. ADJUSTED SKY COVER ACCORDINGLY. CLOUD COVER COULD TRANSLATE
TO SLIGHTLY COOLER THAN EXPECTED TEMPERATURES...BUT GIVEN THE
POTENTIAL FOR MID/HIGH CLOUDS THINNING FOR AT LEAST BREAKS OF
SUNSHINE MAINTAINED HIGHS IN THE LOWER TO MID 60S...WARMEST NEAR
THE ALTAMAHA RIVER. OTHERWISE...FORECAST PARAMETERS REMAIN ON
TRACK AND REQUIRED LITTLE/NO ADJUSTMENT WITHIN THE MORNING UPDATE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
VFR AT KSAV AND KCHS LIKELY THROUGH 12Z SATURDAY. CIGS SHOULD
BEGIN TO LOWER AFTER MIDNIGHT BUT LATEST FORECAST SOUNDINGS
SUGGEST CIGS REMAIN VFR UNTIL 12Z SATURDAY ALTHOUGH SOME LOWER
CLOUDS ARE CERTAINLY POSSIBLE IF RAINS DEVELOP EVEN SOONER THAN
EXPECTED. AS OF THE 12Z CYCLE...THESE RAINS ARE EXPECTED TO BREAK
OUT AFTER MIDNIGHT ACROSS THE COASTAL CORRIDOR BUT MAINLY REMAIN
RELATIVELY LIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
ANOTHER DAY OF LIGHT WINDS AND FLAT SEAS PRIOR TO SOME SLOWLY
BUILDING NE FLOW TONIGHT AS A SECONDARY LOW PRES WAVE DEVELOPS
ALONG THE WEST WALL OF THE GULF STREAM EARLY SATURDAY MORNING.
WINDS WILL REMAIN MAINLY 10 KT OR LESS THROUGH THIS EVENING...THEN WE
WILL SEE NE WINDS INCREASE CLOSER TO 15 KT BY 12Z SATURDAY OFF THE
CHARLESTON COUNTY COAST BUT LESSER SPEEDS FURTHER SOUTHWARD GIVEN
THE ANGLE OF THE DEVELOPING PINCHING GRADIENTS. SEAS LESS THAN 2
FT SEAS MOST OF TODAY WILL BUILD TO 2-3 FT TONIGHT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...SPR
MARINE...DPB/SPR








000
FXUS62 KCHS 191212
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
712 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. UNSETTLED WEATHER IS EXPECTED LATER
TONIGHT THROUGH TUESDAY NIGHT AS SEVERAL DISTURBANCES SHIFT OVER THE
REGION. A COLD FRONT WILL EVENTUALLY SHIFT THROUGH THE AREA ON WEDNESDAY
WITH DRYER CONDITIONS TO FOLLOW THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
WEAK MID LEVEL RIDGING AHEAD AND GENERAL SUBSIDENCE IS ON TAP
TODAY ACROSS THE FORECAST AREA...ALONG WITH THE ARRIVAL OF A WEAK
SURFACE TROUGH THE EASTERN CAROLINAS THIS MORNING. THIS PRECEDES A
PROGRESSIVE SHORT WAVE TROUGH EJECTING THROUGH THE SOUTHERN PLAINS
WHICH WILL TAP SOME MOISTURE FROM THE GULF OF MEXICO AND SPREAD A
MIX OF CONVECTIVE AND STRATIFORM RAINS ACROSS THE LOWER GULF COAST
REGION. PERIODS OF MAINLY HIGH CLOUDS ANTICIPATED TODAY WITH MILD
TEMPS IN THE 60S ALL AREAS THIS AFTERNOON. 00Z H3R...NAM...AND GEM
CLOUD FIELD PROGS INDICATED THICKER HIGH CLOUDS AROUND DAYBREAK...
THINNING LATE MORNING INTO MID AFTERNOON BEFORE EXPANDING LATER IN
THE DAY. WE MAINTAINED STRONG PERSISTENCE WITH OUR PREVIOUS MAX
TEMP FORECAST GIVEN THE LOW LEVEL THICKNESS PROGS AND MAINLY THIN
CLOUDS EXPECTED.

VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHALLOW GROUND FOG AT KCHS AT DAWN...DISSIPATING BY MID MORNING. VFR
AT KSAV AND KCHS LIKELY THROUGH 12Z SATURDAY. CIGS SHOULD BEGIN
TO LOWER AFTER MIDNIGHT BUT LATEST FORECAST SOUNDINGS SUGGEST CIGS
REMAIN VFR UNTIL 12Z SATURDAY ALTHOUGH SOME LOWER CLOUDS ARE CERTAINLY
POSSIBLE IF RAINS DEVELOP EVEN SOONER THAN EXPECTED. AS OF THE 12Z
CYCLE...THESE RAINS ARE EXPECTED TO BREAK OUT AFTER MIDNIGHT
ACROSS THE COASTAL CORRIDOR BUT MAINLY REMAIN RELATIVELY LIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
ANOTHER DAY OF LIGHT WINDS AND FLAT SEAS PRIOR TO SOME SLOWLY
BUILDING NE FLOW TONIGHT AS A SECONDARY LOW PRES WAVE DEVELOPS
ALONG THE WEST WALL OF THE GULF STREAM EARLY SATURDAY MORNING. WE
WILL SEE NE WINDS INCREASE CLOSER TO 15 KT BY 12Z SATURDAY OFF THE
CHARLESTON COUNTY COAST BUT LESSER SPEEDS FURTHER SOUTHWARD GIVEN
THE ANGLE OF THE DEVELOPING PINCHING GRADIENTS. 1-2 FT SEAS MOST
OF TODAY WILL BUILD TO 2-3 FT TONIGHT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB








000
FXUS62 KCHS 191212
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
712 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. UNSETTLED WEATHER IS EXPECTED LATER
TONIGHT THROUGH TUESDAY NIGHT AS SEVERAL DISTURBANCES SHIFT OVER THE
REGION. A COLD FRONT WILL EVENTUALLY SHIFT THROUGH THE AREA ON WEDNESDAY
WITH DRYER CONDITIONS TO FOLLOW THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
WEAK MID LEVEL RIDGING AHEAD AND GENERAL SUBSIDENCE IS ON TAP
TODAY ACROSS THE FORECAST AREA...ALONG WITH THE ARRIVAL OF A WEAK
SURFACE TROUGH THE EASTERN CAROLINAS THIS MORNING. THIS PRECEDES A
PROGRESSIVE SHORT WAVE TROUGH EJECTING THROUGH THE SOUTHERN PLAINS
WHICH WILL TAP SOME MOISTURE FROM THE GULF OF MEXICO AND SPREAD A
MIX OF CONVECTIVE AND STRATIFORM RAINS ACROSS THE LOWER GULF COAST
REGION. PERIODS OF MAINLY HIGH CLOUDS ANTICIPATED TODAY WITH MILD
TEMPS IN THE 60S ALL AREAS THIS AFTERNOON. 00Z H3R...NAM...AND GEM
CLOUD FIELD PROGS INDICATED THICKER HIGH CLOUDS AROUND DAYBREAK...
THINNING LATE MORNING INTO MID AFTERNOON BEFORE EXPANDING LATER IN
THE DAY. WE MAINTAINED STRONG PERSISTENCE WITH OUR PREVIOUS MAX
TEMP FORECAST GIVEN THE LOW LEVEL THICKNESS PROGS AND MAINLY THIN
CLOUDS EXPECTED.

VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHALLOW GROUND FOG AT KCHS AT DAWN...DISSIPATING BY MID MORNING. VFR
AT KSAV AND KCHS LIKELY THROUGH 12Z SATURDAY. CIGS SHOULD BEGIN
TO LOWER AFTER MIDNIGHT BUT LATEST FORECAST SOUNDINGS SUGGEST CIGS
REMAIN VFR UNTIL 12Z SATURDAY ALTHOUGH SOME LOWER CLOUDS ARE CERTAINLY
POSSIBLE IF RAINS DEVELOP EVEN SOONER THAN EXPECTED. AS OF THE 12Z
CYCLE...THESE RAINS ARE EXPECTED TO BREAK OUT AFTER MIDNIGHT
ACROSS THE COASTAL CORRIDOR BUT MAINLY REMAIN RELATIVELY LIGHT.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
ANOTHER DAY OF LIGHT WINDS AND FLAT SEAS PRIOR TO SOME SLOWLY
BUILDING NE FLOW TONIGHT AS A SECONDARY LOW PRES WAVE DEVELOPS
ALONG THE WEST WALL OF THE GULF STREAM EARLY SATURDAY MORNING. WE
WILL SEE NE WINDS INCREASE CLOSER TO 15 KT BY 12Z SATURDAY OFF THE
CHARLESTON COUNTY COAST BUT LESSER SPEEDS FURTHER SOUTHWARD GIVEN
THE ANGLE OF THE DEVELOPING PINCHING GRADIENTS. 1-2 FT SEAS MOST
OF TODAY WILL BUILD TO 2-3 FT TONIGHT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB







000
FXUS62 KCHS 190945
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
445 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. UNSETTLED WEATHER IS EXPECTED LATER
TONIGHT THROUGH TUESDAY NIGHT AS SEVERAL DISTURBANCES SHIFT OVER THE
REGION. A COLD FRONT WILL EVENTUALLY SHIFT THROUGH THE AREA ON WEDNESDAY
WITH DRYER CONDITIONS TO FOLLOW THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...MOST AREAS SHOULD BE STARTING OFF MILDER THIS MORNING.
1000 MB TO 850 MB RH IS ELEVATED FROM 24 HOURS AGO WITH SURFACE DEW
POINTS CLOSER TO 5C ALONG WITH THICKER PATCHES OF CIRROSTRATUS FROM
TIME TO TIME. MANY LOCATIONS SHOULD BE IN THE 38-43 DEGREE RANGE
AROUND DAYBREAK...COOLEST NORTH OF I-16 AND INLAND FROM THE
BEAUFORT-CHARLESTON CORRIDOR.

WEAK MID LEVEL RIDGING AHEAD AND GENERAL SUBSIDENCE IS ON TAP TODAY
ACROSS THE FORECAST AREA...ALONG WITH THE ARRIVAL OF A WEAK SURFACE
TROUGH THE EASTERN CAROLINAS THIS MORNING. THIS PRECEDES A PROGRESSIVE
SHORT WAVE TROUGH EJECTING THROUGH THE SOUTHERN PLAINS WHICH WILL
TAP SOME MOISTURE FROM THE GULF OF MEXICO AND SPREAD A MIX OF CONVECTIVE
AND STRATIFORM RAINS ACROSS THE LOWER GULF COAST REGION. PERIODS
OF MAINLY HIGH CLOUDS ANTICIPATED TODAY WITH MILD TEMPS IN THE 60S
ALL AREAS THIS AFTERNOON. 00Z H3R...NAM...AND GEM CLOUD FIELD PROGS
INDICATED THICKER HIGH CLOUDS AROUND DAYBREAK... THINNING LATE
MORNING INTO MID AFTERNOON BEFORE EXPANDING LATER IN THE DAY. WE
MAINTAINED STRONG PERSISTENCE WITH OUR PREVIOUS MAX TEMP FORECAST
GIVEN THE LOW LEVEL THICKNESS PROGS AND MAINLY THIN CLOUDS EXPECTED.

VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
VFR AT KSAV AND KCHS THROUGH 06Z SATURDAY.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
ANOTHER DAY OF LIGHT WINDS AND FLAT SEAS PRIOR TO SOME SLOWLY
BUILDING NE FLOW TONIGHT AS A SECONDARY LOW PRES WAVE DEVELOPS
ALONG THE WEST WALL OF THE GULF STREAM EARLY SATURDAY MORNING. WE
WILL SEE NE WINDS INCREASE CLOSER TO 15 KT BY 12Z SATURDAY OFF THE
CHARLESTON COUNTY COAST BUT LESSER SPEEDS FURTHER SOUTHWARD GIVEN
THE ANGLE OF THE DEVELOPING PINCHING GRADIENTS. 1-2 FT SEAS MOST
OF TODAY WILL BUILD TO 2-3 FT TONIGHT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB








000
FXUS62 KCHS 190945
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
445 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. UNSETTLED WEATHER IS EXPECTED LATER
TONIGHT THROUGH TUESDAY NIGHT AS SEVERAL DISTURBANCES SHIFT OVER THE
REGION. A COLD FRONT WILL EVENTUALLY SHIFT THROUGH THE AREA ON WEDNESDAY
WITH DRYER CONDITIONS TO FOLLOW THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...MOST AREAS SHOULD BE STARTING OFF MILDER THIS MORNING.
1000 MB TO 850 MB RH IS ELEVATED FROM 24 HOURS AGO WITH SURFACE DEW
POINTS CLOSER TO 5C ALONG WITH THICKER PATCHES OF CIRROSTRATUS FROM
TIME TO TIME. MANY LOCATIONS SHOULD BE IN THE 38-43 DEGREE RANGE
AROUND DAYBREAK...COOLEST NORTH OF I-16 AND INLAND FROM THE
BEAUFORT-CHARLESTON CORRIDOR.

WEAK MID LEVEL RIDGING AHEAD AND GENERAL SUBSIDENCE IS ON TAP TODAY
ACROSS THE FORECAST AREA...ALONG WITH THE ARRIVAL OF A WEAK SURFACE
TROUGH THE EASTERN CAROLINAS THIS MORNING. THIS PRECEDES A PROGRESSIVE
SHORT WAVE TROUGH EJECTING THROUGH THE SOUTHERN PLAINS WHICH WILL
TAP SOME MOISTURE FROM THE GULF OF MEXICO AND SPREAD A MIX OF CONVECTIVE
AND STRATIFORM RAINS ACROSS THE LOWER GULF COAST REGION. PERIODS
OF MAINLY HIGH CLOUDS ANTICIPATED TODAY WITH MILD TEMPS IN THE 60S
ALL AREAS THIS AFTERNOON. 00Z H3R...NAM...AND GEM CLOUD FIELD PROGS
INDICATED THICKER HIGH CLOUDS AROUND DAYBREAK... THINNING LATE
MORNING INTO MID AFTERNOON BEFORE EXPANDING LATER IN THE DAY. WE
MAINTAINED STRONG PERSISTENCE WITH OUR PREVIOUS MAX TEMP FORECAST
GIVEN THE LOW LEVEL THICKNESS PROGS AND MAINLY THIN CLOUDS EXPECTED.

VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
VFR AT KSAV AND KCHS THROUGH 06Z SATURDAY.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
ANOTHER DAY OF LIGHT WINDS AND FLAT SEAS PRIOR TO SOME SLOWLY
BUILDING NE FLOW TONIGHT AS A SECONDARY LOW PRES WAVE DEVELOPS
ALONG THE WEST WALL OF THE GULF STREAM EARLY SATURDAY MORNING. WE
WILL SEE NE WINDS INCREASE CLOSER TO 15 KT BY 12Z SATURDAY OFF THE
CHARLESTON COUNTY COAST BUT LESSER SPEEDS FURTHER SOUTHWARD GIVEN
THE ANGLE OF THE DEVELOPING PINCHING GRADIENTS. 1-2 FT SEAS MOST
OF TODAY WILL BUILD TO 2-3 FT TONIGHT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB








000
FXUS62 KCHS 190945
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
445 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL TODAY. UNSETTLED WEATHER IS EXPECTED LATER
TONIGHT THROUGH TUESDAY NIGHT AS SEVERAL DISTURBANCES SHIFT OVER THE
REGION. A COLD FRONT WILL EVENTUALLY SHIFT THROUGH THE AREA ON WEDNESDAY
WITH DRYER CONDITIONS TO FOLLOW THROUGH LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...MOST AREAS SHOULD BE STARTING OFF MILDER THIS MORNING.
1000 MB TO 850 MB RH IS ELEVATED FROM 24 HOURS AGO WITH SURFACE DEW
POINTS CLOSER TO 5C ALONG WITH THICKER PATCHES OF CIRROSTRATUS FROM
TIME TO TIME. MANY LOCATIONS SHOULD BE IN THE 38-43 DEGREE RANGE
AROUND DAYBREAK...COOLEST NORTH OF I-16 AND INLAND FROM THE
BEAUFORT-CHARLESTON CORRIDOR.

WEAK MID LEVEL RIDGING AHEAD AND GENERAL SUBSIDENCE IS ON TAP TODAY
ACROSS THE FORECAST AREA...ALONG WITH THE ARRIVAL OF A WEAK SURFACE
TROUGH THE EASTERN CAROLINAS THIS MORNING. THIS PRECEDES A PROGRESSIVE
SHORT WAVE TROUGH EJECTING THROUGH THE SOUTHERN PLAINS WHICH WILL
TAP SOME MOISTURE FROM THE GULF OF MEXICO AND SPREAD A MIX OF CONVECTIVE
AND STRATIFORM RAINS ACROSS THE LOWER GULF COAST REGION. PERIODS
OF MAINLY HIGH CLOUDS ANTICIPATED TODAY WITH MILD TEMPS IN THE 60S
ALL AREAS THIS AFTERNOON. 00Z H3R...NAM...AND GEM CLOUD FIELD PROGS
INDICATED THICKER HIGH CLOUDS AROUND DAYBREAK... THINNING LATE
MORNING INTO MID AFTERNOON BEFORE EXPANDING LATER IN THE DAY. WE
MAINTAINED STRONG PERSISTENCE WITH OUR PREVIOUS MAX TEMP FORECAST
GIVEN THE LOW LEVEL THICKNESS PROGS AND MAINLY THIN CLOUDS EXPECTED.

VERY FAST UPPER FLOW ACROSS THE SOUTHEAST STATES CONTINUES TO MAKE
FOR A TRICKY FORECAST INTRODUCING POPS TONIGHT. ALTHOUGH MODELS
MAINTAIN SIMILAR QPF TIMING FROM PREVIOUS RUNS... A SOMEWHAT QUICKER
PROGRESSION OF RAINS IS POSSIBLE AND WE HAD TO MAKE ONLY MINOR
ADJUSTMENTS FROM OUR PREVIOUS THINKING GIVEN CONSENSUS OF CONDENSATION
DEFICIT PROGS AND INITIAL ARRIVAL OF UPPER FORCING. SPRINKLES AND
PATCHY LIGHT RAINS MAY BREAK OUT IN THE EVENING HOURS IN A FEW AREAS
TO THE WEST OF I-95 BUT MUCH HIGHER CONFIDENCE RAINS EXPAND AFTER
06Z WITH CATEGORICAL POPS LATE AS SUNRISE ARRIVES SATURDAY. OVERNIGHT
QPF SHOULD MAINLY BE LIGHT WITH VERTICAL PROFILES ONLY MOISTENING
UP SIGNIFICANTLY LATER IN THE NIGHT. CLOUDS AND RAIN WILL HELP TO
ANCHOR A WEAK WEDGE PATTERN AT THE SURFACE WITH LOWS 40-45 NORTH
AND MID 40S S OF I-16.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY...A WET DAY REMAINS IN THE FORECAST AS ISENTROPIC ASCENT
LIFTS MOISTURE OVER A WEDGE OF HIGH PRESSURE AT THE SFC. ACTIVITY
WILL LIKELY BE ONGOING INTO AT LEAST EARLY AFTERNOON WHILE FORCING
PERSISTS FROM A H5 SHORTWAVE PASSING OVER THE SOUTHEAST AND A STRONG
UPPER LVL JET POSITIONED OVER MUCH OF THE SOUTHERN UNITED STATES.
HOWEVER...THE MID/UPPER PATTERN SUGGESTS A QUICKLY PACED EVENT THAT
OFFERS LESS PRECIP ACCUMULATION...WITH PERHAPS JUST A FEW TENTHS OF
INCH OVER MOST AREAS. PRECIP SHOULD END FROM WEST TO EAST DURING THE
EVENING AS THE DEEPEST MOISTURE SHIFTS OFFSHORE. OVERALL TEMPS WILL
BE COOLER WITHIN THE WEDGE AND UNDER CLOUDY SKIES. EXPECT TEMPS TO
PEAK IN THE LOWER 50S IN SOUTHEAST SOUTH CAROLINA AND MID/UPPER 50S
IN SOUTHEAST GEORGIA. WE COULD SEE A FEW LOCATIONS REACH 60 IN OUR
MOST SOUTHERN ZONES.

SATURDAY NIGHT...WE SHOULD SEE A PERIOD OF DRY WEATHER...BUT
MOISTURE WILL BEGIN INCREASING FROM THE SOUTH AHEAD OF ANOTHER WAVE
OF LOW PRESSURE SHIFTING/DEVELOPING OVER THE NORTHEAST GULF OF
MEXICO. LOW TEMPS SHOULD RANGE IN THE LOW/MID 40S...COOLEST OVER
INLAND SOUTHEAST SOUTH CAROLINA. TEMPS SHOULD BE SLIGHTLY WARMER
ALONG THE IMMEDIATE COAST.

SUNDAY...THE DAY SHOULD START OFF MOSTLY DRY...BUT MODELS ARE IN
GENERAL AGREEMENT THAT MOISTURE WILL BUILD FROM THE SOUTH AS AN AREA
OF LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO SLOWLY SHIFTS OVER
THE SOUTHEASTERN UNITED STATES SUNDAY AFTERNOON AND NIGHT. HAVE
THEREFORE INDICATED 20-30 POPS IN SOUTHEAST GEORGIA SPREADING INTO
SOUTHEAST SOUTH CAROLINA SUNDAY EVENING AND THEN INCREASING UPWARDS
TO AROUND 70 POPS SUNDAY NIGHT FOR ALL AREAS AS THE LOW TRACKS OVER
OR IMMEDIATELY ALONG THE SOUTHEAST COAST. GREATEST CHANCES OF PRECIP
APPEAR TO BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA
COAST AT THIS TIME...ESPECIALLY AS A SERIES OF H5 SHORTWAVES SHIFT
OVER THE AREA SUNDAY NIGHT. OVERALL HIGH TEMPS WILL BE DEPENDENT ON
THE TRACK OF THE SFC LOW...BUT SHOULD REACH THE MID/UPPER 50S OVER
MOST LOCATIONS AWAY FROM THE COAST. TEMPS COULD PEAK IN THE LOWER
60S ALONG COASTAL AREAS IN SOUTHEAST GEORGIA. OVERNIGHT LOWS SHOULD
RANGE IN THE MID/UPPER 40S AWAY FROM THE COAST...AND IN THE LOW 50S
ALONG THE COAST.

MONDAY...SHOWERS WILL LIKELY BE ONGOING TO START OFF THE DAY AS AN
AREA OF LOW PRESSURE CONTINUES TO MAKE WAY TO THE NORTHEAST. MOST
PRECIP SHOULD SHIFT OFFSHORE BY THE AFTERNOON...BUT CHANCES OF
SHOWERS WILL REMAIN IN THE FORECAST THROUGH MUCH OF THE EVENING
WHILE ABUNDANT LOW-LVL MOISTURE LAGS BEHIND THE LOW TO THE
NORTHEAST. TEMPS WILL BE DEPENDENT ON WHAT IS LEFT OF THE WEDGE
INLAND...BUT SHOULD BE SLIGHTLY WARMER...IN THE UPPER 50S INLAND TO
LOWER 60S IN SOUTHEAST GEORGIA AND ALONG THE SOUTH CAROLINA COAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT INTO TUESDAY NIGHT...THE PATTERN WILL REMAIN UNSETTLED
AS AHEAD OF COLD FRONT THAT EVENTUALLY PUSHES THROUGH THE SOUTHEAST
EARLY WEDNESDAY. AT THIS TIME...MODELS SUGGEST CHANCES OF PRECIP
INCREASING MONDAY NIGHT INTO TUESDAY AS A WARM FRONT TRIES TO LIFT
NORTH INTO A WEAKENING WEDGE OF HIGH PRESSURE AT THE SFC. A PERIOD
OF WARMING SHOULD ALSO OCCUR WITHIN A SOUTHERLY FLOW AHEAD OF THE
APPROACHING COLD FRONT TO THE WEST. HAVE THEREFORE INTRODUCED
SHOWERS FOR ALL AREAS...RATHER THAN RAIN. WE COULD SEE ENOUGH
INSTABILITY TO INCLUDE A FEW THUNDERSTORMS IN THE FORECAST SHOULD
TRENDS PERSIST...MAINLY IN SOUTHEAST GEORGIA TUESDAY AFTERNOON AND
EVENING. OVERALL HIGH TEMPS SHOULD RANGE IN THE LOW/MID 60S FOR MOST
AREAS ON TUESDAY...EVEN WITH CLOUD COVER PRESENT. UPPER 60S ARE
EXPECTED OVER SOUTHEAST GEORGIA. CHANCES OF PRECIP SHOULD QUICKLY
DIMINISH AS THE COLD FRONT BEGINS TO SHIFT THROUGH THE AREA LATE
TUESDAY NIGHT. TUESDAY NIGHT LOWS SHOULD RANGE IN THE UPPER 40S TO
AROUND 50 OVER MOST AREAS.

WEDNESDAY THROUGH FRIDAY...A MUCH QUIETER/DRY PERIOD OF WEATHER IS
ANTICIPATED AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A COLD
FRONT SHIFTING OFFSHORE EARLY WEDNESDAY. TEMPS WILL BE SLOW TO WARM
THROUGH THURSDAY...UNTIL HIGH PRESSURE BECOMES MORE CENTERED OVER
THE WESTERN ATLANTIC. OVERALL HIGH TEMPS SHOULD RANGE IN THE
MID/UPPER 50S WEDNESDAY AND THURSDAY...BEFORE SOUTHERLY FLOW RETURNS
TO THE AREA ALONG THE WESTERN EDGE OF HIGH PRESSURE ON FRIDAY. TEMPS
SHOULD PEAK INTO THE LOW/MID 60S BY LATE WEEK.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
VFR AT KSAV AND KCHS THROUGH 06Z SATURDAY.

EXTENDED AVIATION OUTLOOK...PERIODS OF MVFR OR LOWER CONDITIONS
APPEAR LIKELY WITH RAIN/SHOWERS SATURDAY THROUGH TUESDAY WHILE A
WEDGE OF HIGH PRESSURE PERSISTS INLAND AND SEVERAL AREAS OF LOW
PRESSURE SHIFT ALONG THE SOUTHEAST COAST.

&&

.MARINE...
ANOTHER DAY OF LIGHT WINDS AND FLAT SEAS PRIOR TO SOME SLOWLY
BUILDING NE FLOW TONIGHT AS A SECONDARY LOW PRES WAVE DEVELOPS
ALONG THE WEST WALL OF THE GULF STREAM EARLY SATURDAY MORNING. WE
WILL SEE NE WINDS INCREASE CLOSER TO 15 KT BY 12Z SATURDAY OFF THE
CHARLESTON COUNTY COAST BUT LESSER SPEEDS FURTHER SOUTHWARD GIVEN
THE ANGLE OF THE DEVELOPING PINCHING GRADIENTS. 1-2 FT SEAS MOST
OF TODAY WILL BUILD TO 2-3 FT TONIGHT.

SATURDAY THROUGH WEDNESDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THIS WEEKEND AS A WEDGE OF HIGH
PRESSURE STRENGTHENS INLAND AND A LOW PRESSURE SYSTEM SHIFTS FROM THE
NORTHEAST GULF OF MEXICO ALONG THE SOUTHEAST COAST. PERIODS OF
RAIN/SHOWERS WILL CONTINUE OVER THE WATERS INTO EARLY NEXT WEEK
UNTIL A COLD FRONT SHIFTS OFFSHORE WEDNESDAY. STRONG WINDS WILL
ACCOMPANY THE FRONT AS IT SHIFTS OFFSHORE EARLY WEDNESDAY...WITH AT
LEAST SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL WATERS. A
GALE WATCH COULD BE EVENTUALLY NEEDED FOR A PORTION OF THE WATERS ON
WEDNESDAY MORNING AND AFTERNOON AS WINDS GUST TO 30-35 KT. SEAS WILL
ALSO BUILD UPWARDS TO 6-8 FT WEDNESDAY AFTERNOON BEFORE SLOWLY
IMPROVING WEDNESDAY NIGHT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB







000
FXUS62 KCHS 190602
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
102 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL INTO FRIDAY. UNSETTLED WEATHER IS
EXPECTED MUCH OF THE FRIDAY NIGHT THROUGH TUESDAY NIGHT PERIOD AS
SEVERAL DISTURBANCES AND EVENTUALLY A COLD FRONT TOWARD THE MIDDLE
OF NEXT WEEK AFFECT THE AREA.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH PRESSURE WILL EXTEND ACROSS THE AREA OVERNIGHT. A WEAK SURFACE
TROUGH WILL SHIFT SOUTH OVERNIGHT. CIRRUS CLOUDS WILL TRAVERSE THE
SOUTHEAST U.S. THROUGH THE NIGHT RESULTING IN MOSTLY CLEAR TO
PARTLY CLOUDY SKIES. LOWS WILL RANGE FROM THE MID-UPPER 30S INLAND
TO THE MID 40S AT THE BEACHES. NO SIGNIFICANT CHANGES ON MIDNIGHT
UPDATE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...MAINLY JUST AN INCREASE IN MID AND UPPER LEVEL CLOUDS
THROUGH THE DAY WITH NO RAINFALL EXPECTED. TEMPERATURES SHOULD CLIMB
SLIGHTLY ABOVE NORMAL INTO THE LOWER TO MID 60S...WARMEST GENERALLY
SOUTH OF I-16 AND WEST OF I-95. RAIN SHOULD SPREAD INTO THE AREA
FROM THE WEST FRIDAY NIGHT AS DEEPER MOISTURE MOVES IN AHEAD OF LOW
PRESSURE NEAR THE CENTRAL GULF COAST. LOWS SHOULD RANGE FROM THE
LOWER TO MID 40S NORTH AND WEST TO CLOSER TO 50 ALONG THE COAST.

SATURDAY...PRETTY WET AT LEAST THE FIRST PART OF THE DAY WITH
LOWERING RAIN CHANCES FROM WEST TO EAST AS THE DEEPER MOISTURE AND
FORCING SHIFT OFFSHORE. THE QUICK PACE OF THE SYSTEM MEANS THERE
WILL NOT BE A LOT OF RAIN...WITH MOST PLACES LIKELY ONLY GETTING NO
MORE THAN A FEW TENTHS OF AN INCH. WILL BE A RATHER CHILLY DAY WITH
THE HIGH PRESSURE WEDGE IN PLACE LEADING TO CLOUDY SKIES AND COOL
NORTH/NORTHEAST FLOW. OPTED TO STAY BELOW MOS GUIDANCE FOR HIGHS
GIVEN THE PATTERN...MAINLY AROUND 50 NEAR LAKE MOULTRIE WITH LOWER
TO MID 50S ELSEWHERE EXCEPT UPPER 50S TO NEAR 60 NEAR LUDOWICI AND
DARIEN. SATURDAY NIGHT SHOULD BE DRY ALTHOUGH MOISTURE WILL BE
INCREASING AGAIN FROM THE SOUTH AHEAD OF ANOTHER WAVE OF LOW
PRESSURE IN THE NORTHEAST GULF OF MEXICO. LOWS MAINLY AROUND 40
NORTH AND WEST AND NEAR 50 SOUTH AND EAST.

SUNDAY...THERE ARE SOME TIMING UNCERTAINTIES REGARDING AMOUNT OF
DEEP MOISTURE MOVING IN FROM THE SOUTH...WITH THE ECMWF A BIT MORE
AGGRESSIVE THAN THE GFS. FOR NOW WE MAINTAINED HIGHEST CHANCES /30
PERCENT/ NEAR THE COAST AND INTO SOUTHEAST GEORGIA. CLOUDS WILL
LINGER BUT IT SHOULD BE A BIT WARMER THAN SATURDAY WITH MOST LOCALES
IN THE MID TO UPPER 50S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE LONG TERM PERIOD CONTINUES TO LOOK UNSETTLED AND COMPLEX THROUGH
THE MIDDLE OF NEXT WEEK...LEADING TO A BELOW AVERAGE OVERALL
FORECAST CONFIDENCE CONCERNING THE PERIODS OF HIGHEST RAIN CHANCES.
THE INLAND WEDGE WILL PERSIST AS A WAVE DEVELOPS ALONG THE COAST AND
LIFTS OFF TO THE NORTHEAST THROUGH MONDAY. THIS INLAND WEDGE WILL
LINGER THROUGH TUESDAY BEFORE THE MAIN COLD FRONT AND SURFACE LOW
FINALLY SWEEP THROUGH THE REGION. MODELS STILL DISPLAY NOTABLE
DIFFERENCES IN THE DETAILS IN THIS PERIOD...MAINLY THANKS TO
DISCREPANCIES IN HOW DEEP THE UPPER LOW GETS AND THE OVERALL
AMPLITUDE OF THE MID/UPPER LEVEL TROUGH. MOST AREAS WILL EXPERIENCE
A FEW DAYS OF CLOUD COVER WITH PERIODS OF PRECIPITATION UNTIL THE
COLD FRONT FINALLY SWEEPS THROUGH ON WEDNESDAY. POPS HAVE BEEN KEPT
IN THE CHANCE RANGE FOR NOW...THOUGH IT IS EXPECTED TO PERIODS OF
HIGHER POPS WILL BE NEEDED AS THE FORECAST DETAILS BECOME CLEARER.
TEMPERATURES WILL BE BELOW NORMAL THROUGH MID WEEK.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR AT KSAV AND KCHS THROUGH 06Z SATURDAY.

EXTENDED AVIATION OUTLOOK...MVFR CONDITIONS APPEAR LIKELY AS
EARLY AS FRIDAY NIGHT WITH MVFR/IFR CONDITIONS CONTINUING THROUGH
MONDAY AS HIGH PRESSURE BUILDS FROM THE NORTH AND SEVERAL LOW
PRESSURE SYSTEMS MOVE UP THE COAST.

&&

.MARINE...
OVERNIGHT...WEAK PRESSURE PATTERN WILL PERSIST OVER THE WATERS
TONIGHT. VARIABLE WINDS OF AROUND 5 KT OR LESS WILL EVENTUALLY
BECOME NW/N AFTER MIDNIGHT WITH SPEEDS INCREASING TO 5-10 KT. SEAS
WILL BE 1-2 FEET.

A HIGH PRESSURE WEDGE WILL STRENGTHEN A BIT THIS WEEKEND WITH AN
UPPER LEVEL DISTURBANCE BRINGING UNSETTLED WEATHER LATE FRIDAY NIGHT
INTO SATURDAY. A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF
MEXICO WILL THEN SHIFT NORTHEAST THROUGH THE LOCAL WATERS MONDAY.
ALTHOUGH THERE COULD BE SOME WIND SURGES DEPENDING ON THE STRENGTH
AND TRACK OF THE LOW...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY THRESHOLDS THROUGH TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...









000
FXUS62 KCHS 190602
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
102 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL INTO FRIDAY. UNSETTLED WEATHER IS
EXPECTED MUCH OF THE FRIDAY NIGHT THROUGH TUESDAY NIGHT PERIOD AS
SEVERAL DISTURBANCES AND EVENTUALLY A COLD FRONT TOWARD THE MIDDLE
OF NEXT WEEK AFFECT THE AREA.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH PRESSURE WILL EXTEND ACROSS THE AREA OVERNIGHT. A WEAK SURFACE
TROUGH WILL SHIFT SOUTH OVERNIGHT. CIRRUS CLOUDS WILL TRAVERSE THE
SOUTHEAST U.S. THROUGH THE NIGHT RESULTING IN MOSTLY CLEAR TO
PARTLY CLOUDY SKIES. LOWS WILL RANGE FROM THE MID-UPPER 30S INLAND
TO THE MID 40S AT THE BEACHES. NO SIGNIFICANT CHANGES ON MIDNIGHT
UPDATE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...MAINLY JUST AN INCREASE IN MID AND UPPER LEVEL CLOUDS
THROUGH THE DAY WITH NO RAINFALL EXPECTED. TEMPERATURES SHOULD CLIMB
SLIGHTLY ABOVE NORMAL INTO THE LOWER TO MID 60S...WARMEST GENERALLY
SOUTH OF I-16 AND WEST OF I-95. RAIN SHOULD SPREAD INTO THE AREA
FROM THE WEST FRIDAY NIGHT AS DEEPER MOISTURE MOVES IN AHEAD OF LOW
PRESSURE NEAR THE CENTRAL GULF COAST. LOWS SHOULD RANGE FROM THE
LOWER TO MID 40S NORTH AND WEST TO CLOSER TO 50 ALONG THE COAST.

SATURDAY...PRETTY WET AT LEAST THE FIRST PART OF THE DAY WITH
LOWERING RAIN CHANCES FROM WEST TO EAST AS THE DEEPER MOISTURE AND
FORCING SHIFT OFFSHORE. THE QUICK PACE OF THE SYSTEM MEANS THERE
WILL NOT BE A LOT OF RAIN...WITH MOST PLACES LIKELY ONLY GETTING NO
MORE THAN A FEW TENTHS OF AN INCH. WILL BE A RATHER CHILLY DAY WITH
THE HIGH PRESSURE WEDGE IN PLACE LEADING TO CLOUDY SKIES AND COOL
NORTH/NORTHEAST FLOW. OPTED TO STAY BELOW MOS GUIDANCE FOR HIGHS
GIVEN THE PATTERN...MAINLY AROUND 50 NEAR LAKE MOULTRIE WITH LOWER
TO MID 50S ELSEWHERE EXCEPT UPPER 50S TO NEAR 60 NEAR LUDOWICI AND
DARIEN. SATURDAY NIGHT SHOULD BE DRY ALTHOUGH MOISTURE WILL BE
INCREASING AGAIN FROM THE SOUTH AHEAD OF ANOTHER WAVE OF LOW
PRESSURE IN THE NORTHEAST GULF OF MEXICO. LOWS MAINLY AROUND 40
NORTH AND WEST AND NEAR 50 SOUTH AND EAST.

SUNDAY...THERE ARE SOME TIMING UNCERTAINTIES REGARDING AMOUNT OF
DEEP MOISTURE MOVING IN FROM THE SOUTH...WITH THE ECMWF A BIT MORE
AGGRESSIVE THAN THE GFS. FOR NOW WE MAINTAINED HIGHEST CHANCES /30
PERCENT/ NEAR THE COAST AND INTO SOUTHEAST GEORGIA. CLOUDS WILL
LINGER BUT IT SHOULD BE A BIT WARMER THAN SATURDAY WITH MOST LOCALES
IN THE MID TO UPPER 50S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE LONG TERM PERIOD CONTINUES TO LOOK UNSETTLED AND COMPLEX THROUGH
THE MIDDLE OF NEXT WEEK...LEADING TO A BELOW AVERAGE OVERALL
FORECAST CONFIDENCE CONCERNING THE PERIODS OF HIGHEST RAIN CHANCES.
THE INLAND WEDGE WILL PERSIST AS A WAVE DEVELOPS ALONG THE COAST AND
LIFTS OFF TO THE NORTHEAST THROUGH MONDAY. THIS INLAND WEDGE WILL
LINGER THROUGH TUESDAY BEFORE THE MAIN COLD FRONT AND SURFACE LOW
FINALLY SWEEP THROUGH THE REGION. MODELS STILL DISPLAY NOTABLE
DIFFERENCES IN THE DETAILS IN THIS PERIOD...MAINLY THANKS TO
DISCREPANCIES IN HOW DEEP THE UPPER LOW GETS AND THE OVERALL
AMPLITUDE OF THE MID/UPPER LEVEL TROUGH. MOST AREAS WILL EXPERIENCE
A FEW DAYS OF CLOUD COVER WITH PERIODS OF PRECIPITATION UNTIL THE
COLD FRONT FINALLY SWEEPS THROUGH ON WEDNESDAY. POPS HAVE BEEN KEPT
IN THE CHANCE RANGE FOR NOW...THOUGH IT IS EXPECTED TO PERIODS OF
HIGHER POPS WILL BE NEEDED AS THE FORECAST DETAILS BECOME CLEARER.
TEMPERATURES WILL BE BELOW NORMAL THROUGH MID WEEK.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR AT KSAV AND KCHS THROUGH 06Z SATURDAY.

EXTENDED AVIATION OUTLOOK...MVFR CONDITIONS APPEAR LIKELY AS
EARLY AS FRIDAY NIGHT WITH MVFR/IFR CONDITIONS CONTINUING THROUGH
MONDAY AS HIGH PRESSURE BUILDS FROM THE NORTH AND SEVERAL LOW
PRESSURE SYSTEMS MOVE UP THE COAST.

&&

.MARINE...
OVERNIGHT...WEAK PRESSURE PATTERN WILL PERSIST OVER THE WATERS
TONIGHT. VARIABLE WINDS OF AROUND 5 KT OR LESS WILL EVENTUALLY
BECOME NW/N AFTER MIDNIGHT WITH SPEEDS INCREASING TO 5-10 KT. SEAS
WILL BE 1-2 FEET.

A HIGH PRESSURE WEDGE WILL STRENGTHEN A BIT THIS WEEKEND WITH AN
UPPER LEVEL DISTURBANCE BRINGING UNSETTLED WEATHER LATE FRIDAY NIGHT
INTO SATURDAY. A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF
MEXICO WILL THEN SHIFT NORTHEAST THROUGH THE LOCAL WATERS MONDAY.
ALTHOUGH THERE COULD BE SOME WIND SURGES DEPENDING ON THE STRENGTH
AND TRACK OF THE LOW...CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY THRESHOLDS THROUGH TUESDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...








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