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000
FXUS62 KCHS 172231
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
631 PM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE TO THE NORTH WILL SLOWLY WEAKEN THROUGH FRIDAY.
MEANWHILE A LOW PRESSURE SYSTEM WILL MOVE OUT OF THE GULF OF MEXICO
TO A POSITION OFF THE SOUTH CAROLINA COAST FRIDAY NIGHT AND SATURDAY
BEFORE SLOWLY MOVING EAST NORTHEAST AWAY FROM THE AREA. HIGH
PRESSURE WILL BUILD BACK IN EARLY NEXT WEEK. A WEAK COLD FRONT MAY
APPROACH THE AREA FROM THE NORTH BY MID WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
HIGH PRESSURE WILL WEAKEN OVER THE AREA TONIGHT AS LOW PRESSURE
BEGINS TO TAKE SHAPE OVER THE FAR SOUTHERN GULF OF MEXICO. VERY
WEAK ISENTROPIC LIFT HAS BEEN SUPPORTING A DECK OF CLOUDS AROUND
6 KFT ACROSS MUCH OF SOUTHEAST GEORGIA TODAY WHILE MOSTLY SUNNY
SKIES HAVE PREVAILED ACROSS MOST OF SOUTHEAST SOUTH CAROLINA.
ISENTROPIC ASSENT SLOWLY INCREASE OVERNIGHT AND SPREAD NORTH...
BUT CONDENSATION PRESSURE DEFICITS ARE PROGGED TO REMAIN ABOVE 50
BM UNTIL LATE. THEREFORE...MOST OF THE ASSENT WILL GO TOWARDS
CLOUD GENERATION VERSUS LIGHT RAIN. EXPECT MOSTLY CLOUDY SKIES TO
DOMINATE ALL AREAS BY SUNRISE FRIDAY...ALTHOUGH THE MODELS MAY BE
A LITTLE TOO AGGRESSIVE IN MOVING LOW CLOUDS INTO AREAS NORTH OF
HAMPTON-BEAUFORT LINE BY LATE EVENING. ADJUST SKY COVER TO MATCH
EXPECTED TRENDS. CUT BACK ON GRIDDED POPS JUST A BIT ACROSS THE
NORTH WHERE MEASURABLE RAIN IS NOT EXPECTED TO REACH UNTIL LATE
FRIDAY MORNING...BUT DID MAINTAIN 20 PERCENT POPS FOR THE GEORGIA
COASTAL COUNTIES. LOWS FROM THE UPPER 40S WELL INLAND TO THE UPPER
50S/LOWER 60S IMMEDIATE COAST LOOK ON TRACK.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A POWERFUL UPPER LOW WILL MOVE ALONG THE GULF COAST REGION ON FRIDAY
AS A SURFACE LOW PRESSURE SYSTEM MOVES INTO NORTHERN FLORIDA.
MEANWHILE WEAK HIGH PRESSURE WILL PERSIST NORTH OF THE AREA...
ALBEIT GRADUALLY RETREATING TO THE NNE. AS THE DEEP LAYERED LOW
PRESSURE MOVES CLOSER TO THE AREA...LOW-LEVEL FLOW WILL INCREASE OUT
OF THE SOUTHEAST WHILE MID-LEVELS BECOME SOUTHERLY. THE COLUMN WILL
RAPIDLY MOISTEN DURING THE DAY FRIDAY. PWATS ARE EXPECTED TO RANGE
FROM 1.6 TO 1.8 INCHES BY FRIDAY AFTERNOON. A 100 KT JET SHIFTING
INTO THE EASTERN GULF WILL SPREAD UPPER DIVERGENCE ACROSS THE
FORECAST AREA DURING THE AFTERNOON. MODERATE TO STRONG ISENTROPIC
LIFT WILL SPREAD ACROSS SOUTHEAST GA DURING THE MORNING AND THEN
INTO SOUTHERN SC DURING THE AFTERNOON. WE HAVE LIKELY TO CATEGORICAL
POPS FOR FRIDAY...HIGHEST TO THE SOUTH.

WE HAVE BEEN LEANING TOWARD THE GFS AND ECMWF WITH THIS SYSTEM
THOUGH THE ECMWF REMAINS A BIT SLOWER WITH THE LOW TRACK. THE
STRONGEST QC FORCING LOOKS TO PUSH NORTH THROUGH THE AREA FRIDAY
AFTERNOON AND EVENING BEFORE SHIFTING OUT. THIS WILL BE ACCOMPANIED
BY AMPLE FORCING AND A JUICY AIRMASS IN PLACE. THERE WILL BE A
THREAT FOR HEAVY RAINFALL WITH A WIDESPREAD 2-3 INCHES FORECAST BY
WPC. MORE DETAILS IN THE HYDROLOGY SECTION.

THE UPPER LOW WILL MOVE THROUGH ON SATURDAY...BECOMING NEARLY
VERTICALLY STACKED WITH THE SURFACE LOW AS THE SYSTEM MOVES SLOWLY
EAST INTO THE ATLANTIC. LIGHT PRECIP WILL LINGER THROUGH THE DAY DUE
TO ISENTROPIC ASCENT CAUSED BY MOISTURE WRAPPING AROUND THE WESTERN
SIDE OF THE LOW.

IMPROVING CONDITIONS EXPECTED SATURDAY NIGHT AND SUNDAY WITH SOME
POSSIBLE LATE DAY CLEARING.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
OVERALL THE LONG TERM PERIOD LOOKS QUIET FOR THE FORECAST AREA.
RIDGING ALOFT WILL MOVE IN FOR EARLY IN THE WEEK BEHIND THE
DEPARTING UPPER LOW. A WEAK TROUGH MAY MOVE THROUGH BY THE MID WEEK
TIME PERIOD. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH
TUESDAY...WITH A WEAK COLD FRONT ATTEMPTING TO CROSS BY WEDNESDAY.
THERE MAY BE A FEW SHOWERS WITH THE FRONT...BUT POPS HAVE BEEN
LIMITED TO THE SLIGHT CHANCE RANGE. TEMPERATURES FEATURE A WARMING
TREND...REACHING AROUND THE 80 DEGREE MARK BY TUESDAY AND CONTINUING
THROUGH THE END OF THE FORECAST PERIOD.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
LOW CLOUDS WILL EXPAND AND SLOWLY MOVE NORTH LATE TONIGHT INTO
FRIDAY AS LOW PRESSURE APPROACHES FROM THE SOUTH. SUSPECT MODEL
GUIDANCE IS TOO QUICK IN BRINGING MVFR CIGS INTO BOTH TERMINALS
OVERNIGHT...ESPECIALLY AT KCHS. OPTED FOR A SLIGHTLY SLOWER
SOLUTION WITH MVFR CIGS REACHING KSAV BY 10Z. KEPT KCHS JUST ABOVE
MVFR FOR NOW. AN EXPANSIVE AREA OF RAIN WILL MOVE SOUTH-NORTH
DURING THE DAY FRIDAY. EXPECT PREVAILING LIGHT RAIN TO REACH KSAV
BY MID AFTERNOON...ROUGHLY 20Z WITH RAIN LIKELY NOT REACHING KCHS
UNTIL AFTER 00Z SATURDAY. WILL HIGHLIGHT 4SM -RA AT KSAV FOR NOW
WITH NO MENTION OF RAIN AT KCHS JUST YET.

EXTENDED AVIATION OUTLOOK...CHANCES OF SUB-MVFR CONDITIONS ARE
INCREASING...ESPECIALLY BEGINNING FRIDAY NIGHT. THESE CONDITIONS
WILL LIKELY PERSIST THROUGH SATURDAY...IMPROVING SUNDAY AND INTO
EARLY NEXT WEEK.

&&

.MARINE...
TONIGHT...WINDS ARE STILL BLOWING PRETTY GOOD IN THE CHARLESTON
HARBOR THIS AFTERNOON WITH THE VARIOUS WEATHERFLOW SENSORS IN THE
HARBOR INDICATION WINDS NEAR A SOLID 20 KT WITH HIGHER GUSTS. HAVE
ISSUED A SMALL CRAFT ADVISORY UNTIL 10 PM TO COVER. NO OTHER
CHANGES WERE MADE.

SOLID SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL
WATERS OUTSIDE CHARLESTON HARBOR AS THE PRESSURE GRADIENT REMAINS
TIGHT BETWEEN HIGH PRESSURE TO THE NORTH AND DEVELOPING LOW PRESSURE
OVER THE NORTHERN GULF OF MEXICO. WINDS NEAR THE MOUTH OF
CHARLESTON HARBOR COULD SEE 25 KT GUSTS AT TIMES BUT DID NOT THINK
IT WOULD COVER ENOUGH OF THE HARBOR TO WARRANT AN ADVISORY
OVERNIGHT. SEAS WILL REMAIN IN THE 5-8 FT RANGE WITHIN 20 NM AND
UP TO 10 FT OFFSHORE CLOSER TO THE GULF STREAM.

FAIRLY STRONG NORTHEAST FLOW WILL CONTINUE FRIDAY INTO FRIDAY
EVENING BEFORE TEMPORARILY DIMINISHING AS THE SURFACE LOW MOVES
FAIRLY CLOSE TO THE WATERS AND THE STRONGEST GRADIENT SHIFTS NORTH
AND WEST. THEN A STRONG NORTHEAST GRADIENT REDEVELOPS SATURDAY NIGHT
INTO SUNDAY BEHIND THE LOW AS HIGH PRESSURE TRIES TO REBUILD TO THE
WEST. SOLID SMALL CRAFT CONDITIONS EXPECTED FOR MUCH OF THE PERIOD
FRIDAY THROUGH SUNDAY NIGHT WITH THE POSSIBILITY OF GALE CONDITIONS
OVER PORTIONS OF THE WATERS SATURDAY NIGHT AND SUNDAY. WILL MAINTAIN
ONGOING SMALL CRAFT ADVISORIES BUT DISCUSS GALE POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.

RIP CURRENTS...CONSIDERABLE UNCERTAINTY WITH REGARD TO SWELL ON
FRIDAY BUT WE MAINTAINED SIMILAR CONDITIONS TO TODAY WITH 3 FT 10
SEC SWELL. THIS MAINTAINS A MODERATE RISK FOR CHARLESTON AND HIGH
RISK FARTHER SOUTH. AN ENHANCED RISK FOR RIP CURRENTS WILL PERSIST
THROUGH THE WEEKEND AND PERHAPS INTO EARLY NEXT WEEK.

&&

.HYDROLOGY...
PLENTY OF MOISTURE AND FORCING FOR WIDESPREAD MODERATE TO HEAVY
RAINFALL FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. LATEST WPC GUIDANCE
SHOWS 2-3 INCHES DURING THIS PERIOD WITH ISOLATED POCKETS OF 3-4
INCHES. THE LATEST FLASH FLOOD GUIDANCE SHOWS 6 HR VALUES GREATER
THAN 4 INCHES. SINCE WE HAVE NOT SEEN ANY RECENT TORRENTIAL
RAINFALL EVENTS MOST AREAS SHOULD EASILY BE ABLE TO HANDLE THE
EXPECTED RAINFALL. THE ONLY CONCERN WILL BE COASTAL AREAS DUE TO
THE TIDES RUNNING ABOVE NORMAL. THE FRIDAY LATE EVENING HIGH TIDE
COULD BE AT OR NEAR COASTAL FLOOD ADVISORY CRITERIA IN CHARLESTON
AND/OR SAVANNAH DUE TO THE NORTHEAST WINDS. THUS ANY HEAVY
RAINFALL ON TOP OF THE TIDE COULD RESULT IN SIGNIFICANT FLOODING
ISSUES IN URBAN COASTAL LOCATIONS. FOR NOW WE WILL DISCUSS IN THE
HAZARDOUS WEATHER OUTLOOK.

MAIN STEM RIVERS AND ASSOCIATED TRIBUTARIES WILL LIKELY SEE RISES
WITH THE POTENTIAL FOR MINOR FLOODING DEPENDING ON OBSERVED RAINFALL
AMOUNTS.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...HIGH RISK FOR RIP CURRENTS THROUGH FRIDAY EVENING FOR GAZ117-
     119-139-141.
SC...HIGH RISK FOR RIP CURRENTS THROUGH FRIDAY EVENING FOR SCZ048-
     049-051.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ350-352.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR AMZ330.
     SMALL CRAFT ADVISORY FROM 8 AM FRIDAY TO 6 AM EDT MONDAY FOR
     AMZ330.

&&

$$










000
FXUS62 KCHS 172109
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
509 PM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE TO THE NORTH WILL SLOWLY WEAKEN THROUGH FRIDAY.
MEANWHILE A LOW PRESSURE SYSTEM WILL MOVE OUT OF THE GULF OF MEXICO
TO A POSITION OFF THE SOUTH CAROLINA COAST FRIDAY NIGHT AND SATURDAY
BEFORE SLOWLY MOVING EAST NORTHEAST AWAY FROM THE AREA. HIGH
PRESSURE WILL BUILD BACK IN EARLY NEXT WEEK. A WEAK COLD FRONT MAY
APPROACH THE AREA FROM THE NORTH BY MID WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
HIGH PRESSURE WILL CONTINUE NORTH OF THE AREA TONIGHT
ALTHOUGH IT WILL BE WEAKENING WITH TIME AS LOW PRESSURE BEGINS TO
ORGANIZE OVER THE NORTHERN GULF OF MEXICO. DEEP MOISTURE IN ADVANCE
OF THE LOW WILL BEGIN TO ADVECT NORTHWARD INTO THE
AREA...PARTICULARLY SOUTHEAST GEORGIA LATE. LOW-LEVEL ISENTROPIC
ASCENT IS ALSO EXPECTED TO INCREASE LATE WHICH MEANS INCREASING
CLOUDS. HOWEVER...NOT EXPECTING MUCH IN THE WAY OF MEASURABLE
RAINFALL...ESPECIALLY OVER SOUTHERN SOUTH CAROLINA. TEMPS WILL
LIKELY FALL PRETTY QUICKLY THIS EVENING BEFORE LIKELY LEVEL LING OFF
AND/OR EVEN RISING LATE TONIGHT...ESPECIALLY OVER SOUTHEAST GEORGIA
WHERE CLOUDS WILL BE THICKENING EARLIEST. LOWS SHOULD RANGE FROM
THE UPPER 40S INLAND TO MID TO UPPER 50S AT THE COAST...WARMEST
ACROSS GA.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A POWERFUL UPPER LOW WILL MOVE ALONG THE GULF COAST REGION ON FRIDAY
AS A SURFACE LOW PRESSURE SYSTEM MOVES INTO NORTHERN FLORIDA.
MEANWHILE WEAK HIGH PRESSURE WILL PERSIST NORTH OF THE AREA...
ALBEIT GRADUALLY RETREATING TO THE NNE. AS THE DEEP LAYERED LOW
PRESSURE MOVES CLOSER TO THE AREA...LOW-LEVEL FLOW WILL INCREASE OUT
OF THE SOUTHEAST WHILE MID-LEVELS BECOME SOUTHERLY. THE COLUMN WILL
RAPIDLY MOISTEN DURING THE DAY FRIDAY. PWATS ARE EXPECTED TO RANGE
FROM 1.6 TO 1.8 INCHES BY FRIDAY AFTERNOON. A 100 KT JET SHIFTING
INTO THE EASTERN GULF WILL SPREAD UPPER DIVERGENCE ACROSS THE
FORECAST AREA DURING THE AFTERNOON. MODERATE TO STRONG ISENTROPIC
LIFT WILL SPREAD ACROSS SOUTHEAST GA DURING THE MORNING AND THEN
INTO SOUTHERN SC DURING THE AFTERNOON. WE HAVE LIKELY TO CATEGORICAL
POPS FOR FRIDAY...HIGHEST TO THE SOUTH.

WE HAVE BEEN LEANING TOWARD THE GFS AND ECMWF WITH THIS SYSTEM
THOUGH THE ECMWF REMAINS A BIT SLOWER WITH THE LOW TRACK. THE
STRONGEST QC FORCING LOOKS TO PUSH NORTH THROUGH THE AREA FRIDAY
AFTERNOON AND EVENING BEFORE SHIFTING OUT. THIS WILL BE ACCOMPANIED
BY AMPLE FORCING AND A JUICY AIRMASS IN PLACE. THERE WILL BE A
THREAT FOR HEAVY RAINFALL WITH A WIDESPREAD 2-3 INCHES FORECAST BY
WPC. MORE DETAILS IN THE HYDROLOGY SECTION.

THE UPPER LOW WILL MOVE THROUGH ON SATURDAY...BECOMING NEARLY
VERTICALLY STACKED WITH THE SURFACE LOW AS THE SYSTEM MOVES SLOWLY
EAST INTO THE ATLANTIC. LIGHT PRECIP WILL LINGER THROUGH THE DAY DUE
TO ISENTROPIC ASCENT CAUSED BY MOISTURE WRAPPING AROUND THE WESTERN
SIDE OF THE LOW.

IMPROVING CONDITIONS EXPECTED SATURDAY NIGHT AND SUNDAY WITH SOME
POSSIBLE LATE DAY CLEARING.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
OVERALL THE LONG TERM PERIOD LOOKS QUIET FOR THE FORECAST AREA.
RIDGING ALOFT WILL MOVE IN FOR EARLY IN THE WEEK BEHIND THE
DEPARTING UPPER LOW. A WEAK TROUGH MAY MOVE THROUGH BY THE MID WEEK
TIME PERIOD. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH
TUESDAY...WITH A WEAK COLD FRONT ATTEMPTING TO CROSS BY WEDNESDAY.
THERE MAY BE A FEW SHOWERS WITH THE FRONT...BUT POPS HAVE BEEN
LIMITED TO THE SLIGHT CHANCE RANGE. TEMPERATURES FEATURE A WARMING
TREND...REACHING AROUND THE 80 DEGREE MARK BY TUESDAY AND CONTINUING
THROUGH THE END OF THE FORECAST PERIOD.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH AT LEAST 06Z...THEN MVFR/POSSIBLY IFR CIGS. SHOWERS TO
MOVE IN FROM THE SOUTH...LIKELY IMPACTING KSAV INITIALLY. THE RAIN
COULD BE MODERATE TO HEAVY AT TIMES WHICH COULD REDUCE VSBY AS
WELL. NE WINDS WILL BE GUSTY AT TIMES ...LIKELY THE STRONGEST
AFTER DAYBREAK FRI AS THE PRESSURE GRADIENT TIGHTENS MORE AS LOW
PRESSURE BEGINS TO APPROACH FROM THE SOUTHWEST.

EXTENDED AVIATION OUTLOOK...CHANCES OF SUB-VFR CONDITIONS ARE
INCREASING...ESPECIALLY BEGINNING FRIDAY NIGHT. THESE CONDITIONS
WILL LIKELY PERSIST THROUGH SATURDAY...IMPROVING SUNDAY AND INTO
EARLY NEXT WEEK.

&&

.MARINE...
TONIGHT...WINDS ARE STILL BLOWING PRETTY GOOD IN THE CHARLESTON
HARBOR THIS AFTERNOON WITH THE VARIOUS WEATHERFLOW SENSORS IN THE
HARBOR INDICATION WINDS NEAR A SOLID 20 KT WITH HIGHER GUSTS. HAVE
ISSUED A SMALL CRAFT ADVISORY UNTIL 10 PM TO COVER. NO OTHER
CHANGES WERE MADE.

SOLID SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL
WATERS OUTSIDE CHARLESTON HARBOR AS THE PRESSURE GRADIENT REMAINS
TIGHT BETWEEN HIGH PRESSURE TO THE NORTH AND DEVELOPING LOW PRESSURE
OVER THE NORTHERN GULF OF MEXICO. WINDS NEAR THE MOUTH OF
CHARLESTON HARBOR COULD SEE 25 KT GUSTS AT TIMES BUT DID NOT THINK
IT WOULD COVER ENOUGH OF THE HARBOR TO WARRANT AN ADVISORY
OVERNIGHT. SEAS WILL REMAIN IN THE 5-8 FT RANGE WITHIN 20 NM AND
UP TO 10 FT OFFSHORE CLOSER TO THE GULF STREAM.

FAIRLY STRONG NORTHEAST FLOW WILL CONTINUE FRIDAY INTO FRIDAY
EVENING BEFORE TEMPORARILY DIMINISHING AS THE SURFACE LOW MOVES
FAIRLY CLOSE TO THE WATERS AND THE STRONGEST GRADIENT SHIFTS NORTH
AND WEST. THEN A STRONG NORTHEAST GRADIENT REDEVELOPS SATURDAY NIGHT
INTO SUNDAY BEHIND THE LOW AS HIGH PRESSURE TRIES TO REBUILD TO THE
WEST. SOLID SMALL CRAFT CONDITIONS EXPECTED FOR MUCH OF THE PERIOD
FRIDAY THROUGH SUNDAY NIGHT WITH THE POSSIBILITY OF GALE CONDITIONS
OVER PORTIONS OF THE WATERS SATURDAY NIGHT AND SUNDAY. WILL MAINTAIN
ONGOING SMALL CRAFT ADVISORIES BUT DISCUSS GALE POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.

RIP CURRENTS...CONSIDERABLE UNCERTAINTY WITH REGARD TO SWELL ON
FRIDAY BUT WE MAINTAINED SIMILAR CONDITIONS TO TODAY WITH 3 FT 10
SEC SWELL. THIS MAINTAINS A MODERATE RISK FOR CHARLESTON AND HIGH
RISK FARTHER SOUTH. AN ENHANCED RISK FOR RIP CURRENTS WILL PERSIST
THROUGH THE WEEKEND AND PERHAPS INTO EARLY NEXT WEEK.

&&

.HYDROLOGY...
PLENTY OF MOISTURE AND FORCING FOR WIDESPREAD MODERATE TO HEAVY
RAINFALL FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. LATEST WPC GUIDANCE
SHOWS 2-3 INCHES DURING THIS PERIOD WITH ISOLATED POCKETS OF 3-4
INCHES. THE LATEST FLASH FLOOD GUIDANCE SHOWS 6 HR VALUES GREATER
THAN 4 INCHES. SINCE WE HAVE NOT SEEN ANY RECENT TORRENTIAL
RAINFALL EVENTS MOST AREAS SHOULD EASILY BE ABLE TO HANDLE THE
EXPECTED RAINFALL. THE ONLY CONCERN WILL BE COASTAL AREAS DUE TO
THE TIDES RUNNING ABOVE NORMAL. THE FRIDAY LATE EVENING HIGH TIDE
COULD BE AT OR NEAR COASTAL FLOOD ADVISORY CRITERIA IN CHARLESTON
AND/OR SAVANNAH DUE TO THE NORTHEAST WINDS. THUS ANY HEAVY
RAINFALL ON TOP OF THE TIDE COULD RESULT IN SIGNIFICANT FLOODING
ISSUES IN URBAN COASTAL LOCATIONS. FOR NOW WE WILL DISCUSS IN THE
HAZARDOUS WEATHER OUTLOOK.

MAIN STEM RIVERS AND ASSOCIATED TRIBUTARIES WILL LIKELY SEE RISES
WITH THE POTENTIAL FOR MINOR FLOODING DEPENDING ON OBSERVED RAINFALL
AMOUNTS.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...HIGH RISK FOR RIP CURRENTS THROUGH FRIDAY EVENING FOR GAZ117-
     119-139-141.
SC...HIGH RISK FOR RIP CURRENTS THROUGH FRIDAY EVENING FOR SCZ048-
     049-051.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ350-352.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR AMZ330.
     SMALL CRAFT ADVISORY FROM 8 AM FRIDAY TO 6 AM EDT MONDAY FOR
     AMZ330.

&&

$$

ST








000
FXUS62 KCHS 172004
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
404 PM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE TO THE NORTH WILL SLOWLY WEAKEN THROUGH FRIDAY.
MEANWHILE A LOW PRESSURE SYSTEM WILL MOVE OUT OF THE GULF OF MEXICO
TO A POSITION OFF THE SOUTH CAROLINA COAST FRIDAY NIGHT AND SATURDAY
BEFORE SLOWLY MOVING EAST NORTHEAST AWAY FROM THE AREA. HIGH
PRESSURE WILL BUILD BACK IN EARLY NEXT WEEK. A WEAK COLD FRONT MAY
APPROACH THE AREA FROM THE NORTH BY MID WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
HIGH PRESSURE WILL CONTINUE NORTH OF THE AREA TONIGHT
ALTHOUGH IT WILL BE WEAKENING WITH TIME AS LOW PRESSURE BEGINS TO
ORGANIZE OVER THE NORTHERN GULF OF MEXICO. DEEP MOISTURE IN ADVANCE
OF THE LOW WILL BEGIN TO ADVECT NORTHWARD INTO THE
AREA...PARTICULARLY SOUTHEAST GEORGIA LATE. LOW-LEVEL ISENTROPIC
ASCENT IS ALSO EXPECTED TO INCREASE LATE WHICH MEANS INCREASING
CLOUDS. HOWEVER...NOT EXPECTING MUCH IN THE WAY OF MEASURABLE
RAINFALL...ESPECIALLY OVER SOUTHERN SOUTH CAROLINA. TEMPS WILL
LIKELY FALL PRETTY QUICKLY THIS EVENING BEFORE LIKELY LEVEL LING OFF
AND/OR EVEN RISING LATE TONIGHT...ESPECIALLY OVER SOUTHEAST GEORGIA
WHERE CLOUDS WILL BE THICKENING EARLIEST. LOWS SHOULD RANGE FROM
THE UPPER 40S INLAND TO MID TO UPPER 50S AT THE COAST...WARMEST
ACROSS GA.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A POWERFUL UPPER LOW WILL MOVE ALONG THE GULF COAST REGION ON FRIDAY
AS A SURFACE LOW PRESSURE SYSTEM MOVES INTO NORTHERN FLORIDA.
MEANWHILE WEAK HIGH PRESSURE WILL PERSIST NORTH OF THE AREA...
ALBEIT GRADUALLY RETREATING TO THE NNE. AS THE DEEP LAYERED LOW
PRESSURE MOVES CLOSER TO THE AREA...LOW-LEVEL FLOW WILL INCREASE OUT
OF THE SOUTHEAST WHILE MID-LEVELS BECOME SOUTHERLY. THE COLUMN WILL
RAPIDLY MOISTEN DURING THE DAY FRIDAY. PWATS ARE EXPECTED TO RANGE
FROM 1.6 TO 1.8 INCHES BY FRIDAY AFTERNOON. A 100 KT JET SHIFTING
INTO THE EASTERN GULF WILL SPREAD UPPER DIVERGENCE ACROSS THE
FORECAST AREA DURING THE AFTERNOON. MODERATE TO STRONG ISENTROPIC
LIFT WILL SPREAD ACROSS SOUTHEAST GA DURING THE MORNING AND THEN
INTO SOUTHERN SC DURING THE AFTERNOON. WE HAVE LIKELY TO CATEGORICAL
POPS FOR FRIDAY...HIGHEST TO THE SOUTH.

WE HAVE BEEN LEANING TOWARD THE GFS AND ECMWF WITH THIS SYSTEM
THOUGH THE ECMWF REMAINS A BIT SLOWER WITH THE LOW TRACK. THE
STRONGEST QC FORCING LOOKS TO PUSH NORTH THROUGH THE AREA FRIDAY
AFTERNOON AND EVENING BEFORE SHIFTING OUT. THIS WILL BE ACCOMPANIED
BY AMPLE FORCING AND A JUICY AIRMASS IN PLACE. THERE WILL BE A
THREAT FOR HEAVY RAINFALL WITH A WIDESPREAD 2-3 INCHES FORECAST BY
WPC. MORE DETAILS IN THE HYDROLOGY SECTION.

THE UPPER LOW WILL MOVE THROUGH ON SATURDAY...BECOMING NEARLY
VERTICALLY STACKED WITH THE SURFACE LOW AS THE SYSTEM MOVES SLOWLY
EAST INTO THE ATLANTIC. LIGHT PRECIP WILL LINGER THROUGH THE DAY DUE
TO ISENTROPIC ASCENT CAUSED BY MOISTURE WRAPPING AROUND THE WESTERN
SIDE OF THE LOW.

IMPROVING CONDITIONS EXPECTED SATURDAY NIGHT AND SUNDAY WITH SOME
POSSIBLE LATE DAY CLEARING.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
OVERALL THE LONG TERM PERIOD LOOKS QUIET FOR THE FORECAST AREA.
RIDGING ALOFT WILL MOVE IN FOR EARLY IN THE WEEK BEHIND THE
DEPARTING UPPER LOW. A WEAK TROUGH MAY MOVE THROUGH BY THE MID WEEK
TIME PERIOD. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH
TUESDAY...WITH A WEAK COLD FRONT ATTEMPTING TO CROSS BY WEDNESDAY.
THERE MAY BE A FEW SHOWERS WITH THE FRONT...BUT POPS HAVE BEEN
LIMITED TO THE SLIGHT CHANCE RANGE. TEMPERATURES FEATURE A WARMING
TREND...REACHING AROUND THE 80 DEGREE MARK BY TUESDAY AND CONTINUING
THROUGH THE END OF THE FORECAST PERIOD.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH AT LEAST 06Z...THEN MVFR/POSSIBLY IFR CIGS. SHOWERS TO
MOVE IN FROM THE SOUTH...LIKELY IMPACTING KSAV INITIALLY. THE RAIN
COULD BE MODERATE TO HEAVY AT TIMES WHICH COULD REDUCE VSBY AS
WELL. NE WINDS WILL BE GUSTY AT TIMES ...LIKELY THE STRONGEST
AFTER DAYBREAK FRI AS THE PRESSURE GRADIENT TIGHTENS MORE AS LOW
PRESSURE BEGINS TO APPROACH FROM THE SOUTHWEST.

EXTENDED AVIATION OUTLOOK...CHANCES OF SUB-VFR CONDITIONS ARE
INCREASING...ESPECIALLY BEGINNING FRIDAY NIGHT. THESE CONDITIONS
WILL LIKELY PERSIST THROUGH SATURDAY...IMPROVING SUNDAY AND INTO
EARLY NEXT WEEK.

&&

.MARINE...
TONIGHT...SOLID SMALL CRAFT ADVISORY CONDITIONS EXPECTED FOR ALL
WATERS OUTSIDE CHARLESTON HARBOR AS THE PRESSURE GRADIENT REMAINS
TIGHT BETWEEN HIGH PRESSURE TO THE NORTH AND DEVELOPING LOW PRESSURE
OVER THE NORTHERN GULF OF MEXICO. WINDS NEAR THE MOUTH OF
CHARLESTON HARBOR COULD SEE 25 KT GUSTS AT TIMES BUT DIDN/T THINK
IT WOULD COVER ENOUGH OF THE HARBOR TO WARRANT AN ADVISORY. SEAS
WILL REMAIN IN THE 5-8 FT RANGE WITHIN 20 NM AND UP TO 10 FT
OFFSHORE CLOSER TO THE GULF STREAM.

FAIRLY STRONG NORTHEAST FLOW WILL CONTINUE FRIDAY INTO FRIDAY
EVENING BEFORE TEMPORARILY DIMINISHING AS THE SURFACE LOW MOVES
FAIRLY CLOSE TO THE WATERS AND THE STRONGEST GRADIENT SHIFTS NORTH
AND WEST. THEN A STRONG NORTHEAST GRADIENT REDEVELOPS SATURDAY NIGHT
INTO SUNDAY BEHIND THE LOW AS HIGH PRESSURE TRIES TO REBUILD TO THE
WEST. SOLID SMALL CRAFT CONDITIONS EXPECTED FOR MUCH OF THE PERIOD
FRIDAY THROUGH SUNDAY NIGHT WITH THE POSSIBILITY OF GALE CONDITIONS
OVER PORTIONS OF THE WATERS SATURDAY NIGHT AND SUNDAY. WILL MAINTAIN
ONGOING SMALL CRAFT ADVISORIES BUT DISCUSS GALE POTENTIAL IN THE
HAZARDOUS WEATHER OUTLOOK.

RIP CURRENTS...CONSIDERABLE UNCERTAINTY WITH REGARD TO SWELL ON
FRIDAY BUT WE MAINTAINED SIMILAR CONDITIONS TO TODAY WITH 3 FT 10
SEC SWELL. THIS MAINTAINS A MODERATE RISK FOR CHARLESTON AND HIGH
RISK FARTHER SOUTH. AN ENHANCED RISK FOR RIP CURRENTS WILL PERSIST
THROUGH THE WEEKEND AND PERHAPS INTO EARLY NEXT WEEK.

&&

.HYDROLOGY...
PLENTY OF MOISTURE AND FORCING FOR WIDESPREAD MODERATE TO HEAVY
RAINFALL FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. LATEST WPC GUIDANCE
SHOWS 2-3 INCHES DURING THIS PERIOD. THE LATEST FLASH FLOOD GUIDANCE
SHOWS 6 HR VALUES GREATER THAN 4 INCHES. SINCE WE HAVE NOT SEEN ANY
RECENT TORRENTIAL RAINFALL EVENTS MOST AREAS SHOULD EASILY BE ABLE
TO HANDLE THE EXPECTED RAINFALL. THE ONLY CONCERN WILL BE COASTAL
AREAS DUE TO THE TIDES RUNNING ABOVE NORMAL. THE FRIDAY LATE EVENING
HIGH TIDE COULD BE AT OR NEAR COASTAL FLOOD ADVISORY CRITERIA IN
CHARLESTON AND/OR SAVANNAH DUE TO THE NORTHEAST WINDS. THUS ANY
HEAVY RAINFALL ON TOP OF THE TIDE COULD RESULT IN SIGNIFICANT
FLOODING ISSUES IN URBAN COASTAL LOCATIONS. FOR NOW WE WILL DISCUSS
IN THE HAZARDOUS WEATHER OUTLOOK.

MAIN STEM RIVERS AND ASSOCIATED TRIBUTARIES WILL LIKELY SEE RISES
WITH THE POTENTIAL FOR MINOR FLOODING DEPENDING ON OBSERVED RAINFALL
AMOUNTS.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...HIGH RISK FOR RIP CURRENTS THROUGH FRIDAY EVENING FOR GAZ117-
     119-139-141.
SC...HIGH RISK FOR RIP CURRENTS THROUGH FRIDAY EVENING FOR SCZ048-
     051.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ350-352.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 8 AM FRIDAY TO 6 AM EDT MONDAY FOR
     AMZ330.

&&

$$

SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...JRL
LONG TERM...BSH
AVIATION...RJB/JRL
MARINE...RJB/JRL
HYDROLOGY...
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 171803
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
203 PM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED WELL NORTH OF THE REGION WILL PERSIST THROUGH
TONIGHT...ALTHOUGH WILL BE SLOWLY WEAKENING WITH TIME. AN AREA OF
LOW PRESSURE WILL DEVELOP OVER THE NORTHEAST GULF OF MEXICO ON
FRIDAY. THIS LOW WILL THEN SLOWLY CROSS FLORIDA AND EVENTUALLY
MOVE OFF THE SOUTHEAST COAST BY THE LATTER PART OF THE WEEKEND.
HIGH PRESSURE WILL BUILD BACK IN EARLY NEXT WEEK. A WEAK COLD
FRONT MAY APPROACH THE AREA FROM THE NORTH BY MID WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...NO MAJOR CHANGES. SKIES HAVE CLEARED ACROSS MOST OF
SOUTHEAST SOUTH CAROLINA BUT REMAIN RATHER CLOUDY ACROSS SOUTHEAST
GEORGIA...WHICH SHOULD BE THE TREND THE REST OF THE AFTERNOON.
TEMPS SHOULD TOP OUT IN THE UPPER 60S AWAY FROM THE LOCALLY COOLER
IMMEDIATE COASTAL LOCALES...ALTHOUGH SOME SPOTS COULD TOUCH 70. IT
WILL ALSO BE BREEZY AT TIMES WITH SOME GUSTS NEAR 25 MPH...MAINLY
NEAR THE COAST.

TONIGHT...HIGH CLOUDS WILL THICKEN OVERNIGHT AHEAD OF A
DEVELOPING GULF COAST SYSTEM. INCREASING DYNAMICS AND MOISTURE
CONVERGENCE TO OUR SW WILL SPREAD RAINS INTO THE FLORIDA PANHANDLE
AND SW GEORGIA AFTER MIDNIGHT. THE RISK FOR WET WEATHER IS
EXPECTED TO HOLD OFF UNTIL TOWARD DAYBREAK ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. CLOUDS AND LINGERING NE WINDS SHOULD
KEEP TEMPS MILDER OVERNIGHT...RANGING FROM THE MID TO UPPER 40S NW
TIER TO LOWER/MID 50S ALONG THE COAST.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY THROUGH SATURDAY...CONFIDENCE HAS INCREASED SIGNIFICANTLY IN
AN ACTIVE AND VERY WET SCENARIO FOR THE FORECAST AREA. OTHER THAN
THE NAM...THE LATEST RUNS OF THE SUITE OF FORECAST MODELS HAVE
CONVERGED ON A SOLUTION THAT FAVORS A WIDESPREAD SIGNIFICANT
RAINFALL EVENT STRETCHING FROM THE FLORIDA PANHANDLE AND UP THE
GEORGIA/SOUTH CAROLINA COASTLINE. ON FRIDAY...A SOUTHERN STREAM
SHORTWAVE WILL CROSS THE LOWER MISSISSIPPI VALLEY AND INTENSIFY INTO
A CLOSED LOW ACROSS THE DEEP SOUTH. AN IMPRESSIVE DEGREE OF FORCING
WILL TAKE SHAPE WITH RIGHT ENTRANCE REGION UPPER JET
DYNAMICS...STRONG LOW/MID LEVEL FRONTOGENESIS...AND DEEP MOIST
CONVERGENCE ALL ALIGNING ACROSS THE REGION ESPECIALLY FRIDAY NIGHT.
FURTHERMORE...PWATS WILL SURGE TO IN EXCESS OF 1.75 INCHES WHICH
WOULD EXCEED THE 99TH PERCENTILE FOR MID APRIL. PRECIPITATION WILL
INVADE FROM THE SOUTH ON FRIDAY...BECOMING MOST WIDESPREAD FRIDAY
NIGHT. POPS HAVE BEEN ALTERED DRAMATICALLY AND NOW FEATURE NEAR 100
PERCENT CHANCES BY LATE FRIDAY NIGHT. GIVEN THE PRESENCE OF THE
STRONG FORCING AND VERY MOIST AIRMASS...WIDESPREAD MODERATE TO
OCCASIONALLY HEAVY RAIN WILL OCCUR JUST ABOUT EVERYWHERE. BY
SATURDAY MORNING...SOME MODEL SOLUTIONS INDICATE A HIGH PROBABILITY
OF WIDESPREAD RAINFALL AMOUNTS OF 3 OR MORE INCHES. POPS THEN
DECREASE FROM WEST TO EAST DURING THE DAY ON SATURDAY AS THE FORCING
SHIFTS OFFSHORE AND THE SLOW MOVING SURFACE LOW DRIFTS OFF THE
FLORIDA COASTLINE. OF LESSER IMPACT...THE MODELS INDICATE THE
PRESENCE OF A SLOT OF STEEPENING MID LEVEL LAPSE RATES AND NEGATIVE
SHOWALTER INDICES FRIDAY NIGHT. THIS MAY RESULT IN SOME ELEVATED
THUNDERSTORM ACTIVITY...BUT FOR NOW THE HIGHEST PROBABILITIES ARE
OVER THE ADJACENT COASTAL WATERS. THUNDER MAY EVENTUALLY NEED TO BE
ADDED TO INLAND AREAS. THE FORECAST AREA HAS BEEN ADDED TO THE DAY 2
EXCESSIVE RAINFALL OUTLOOK FROM WPC...BUT CURRENT THINKING IS THAT
WIDESPREAD FLASH FLOODING IS NOT EXPECTED SO NOTHING WILL BE ADDED
TO THE HWO. THIS THREAT WILL NEED TO BE REEVALUATED WITH FUTURE
FORECAST PACKAGES. TEMPERATURES WILL BE HELD DOWN BY THE WIDESPREAD
CLOUDS AND PRECIPITATION SO FRIDAY HIGHS WILL BE KEPT IN THE LOW
60S...AND SATURDAY HIGHS IN THE MID/UPPER 60S.

SUNDAY...CONDITIONS WILL INCREASE AS THE COLUMN DRIES OUT AND THE
SURFACE LOW MOVES FURTHER OFFSHORE. IN FACT LAND AREAS ARE EXPECTED
TO BE DRY WITH JUST LOW END CHANCES OVER THE COASTAL WATERS. WE MAY
HAVE TO DEAL WITH CONSIDERABLE WRAP AROUND CLOUDINESS WHICH MAY
NEGATIVELY IMPACT TEMPERATURES. FOR NOW...THE FORECAST FEATURES LOW
70S JUST ABOUT EVERYWHERE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
OVERALL THE LONG TERM PERIOD LOOKS QUIET FOR THE FORECAST AREA.
RIDGING ALOFT WILL MOVE IN FOR EARLY IN THE WEEK BEHIND THE
DEPARTING UPPER LOW. A WEAK TROUGH MAY MOVE THROUGH BY THE MID WEEK
TIME PERIOD. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH
TUESDAY...WITH A WEAK COLD FRONT ATTEMPTING TO CROSS BY WEDNESDAY.
THERE MAY BE A FEW SHOWERS WITH THE FRONT...BUT POPS HAVE BEEN
LIMITED TO THE SLIGHT CHANCE RANGE. TEMPERATURES FEATURE A WARMING
TREND...REACHING AROUND THE 80 DEGREE MARK BY TUESDAY AND CONTINUING
THROUGH THE END OF THE FORECAST PERIOD.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH AT LEAST 06Z...THEN MVFR/POSSIBLY IFR CIGS. SHOWERS TO
MOVE IN FROM THE SOUTH...LIKELY IMPACTING KSAV INITIALLY. THE RAIN
COULD BE MODERATE TO HEAVY AT TIMES WHICH COULD REDUCE VSBY AS
WELL. NE WINDS WILL BE GUSTY AT TIMES ...LIKELY THE STRONGEST
AFTER DAYBREAK FRI AS THE PRESSURE GRADIENT TIGHTENS MORE AS LOW
PRESSURE BEGINS TO APPROACH FROM THE SOUTHWEST.

EXTENDED AVIATION OUTLOOK...CHANCES OF SUB-VFR CONDITIONS ARE
INCREASING...ESPECIALLY BEGINNING FRIDAY NIGHT. THESE CONDITIONS
WILL LIKELY PERSIST THROUGH SATURDAY...IMPROVING SUNDAY AND INTO
EARLY NEXT WEEK.

&&

.MARINE...
SOLID SMALL CRAFT ADVISORY CONDITIONS EXPECTED THROUGH TONIGHT AS
THE PRES GRADIENT REMAINS TIGHT BETWEEN HIGH PRES WEDGED DOWN THE
LEE OF THE MOUNTAINS AND DEVELOPING LOW PRES BY TONIGHT OVER
THE NE GULF OF MEXICO. MODELS SUGGEST THE ONGOING SURGE IN THE
20-25 KT WITH GUSTS TO 30 KT MAY EBB ALONG THE CHARLESTON COUNTY
COAST LATER TODAY AND THIS EVENING TO MORE OF A 15-20 KT FLOW
BUT THEN SURGE AGAIN AFTER MIDNIGHT FRIDAY MORNING. OVER GEORGIA
WATERS...NOT MUCH OF A LULL WITH THE STEADY NE FLOW THROUGH
TONIGHT WITH POTENTIAL FOR PINCHING TO PERSIST RIGHT ALONG COASTAL
BEAUFORT AND CHATHAM COUNTIES GIVEN THE ALIGNMENT OF THE ENHANCED
MOISTURE GRADIENTS. SEAS WILL REMAIN IN THE 5-8 FT RANGE WITHIN
20 NM AND UP TO 10 FT OFFSHORE CLOSER TO THE GULF STREAM INTO
TONIGHT.

FRIDAY THROUGH MONDAY...A STRONG NORTHEAST GRADIENT WILL PERSIST
THROUGH FRIDAY BETWEEN HIGH PRESSURE TO THE NORTH AND DEVELOPING LOW
PRESSURE TO THE SOUTH. FORECAST UNCERTAINTY THEN INCREASES FRIDAY
NIGHT ONWARD AS THE SURFACE LOW BEGINS TO MOVE OUT OF THE NORTHEAST
GULF OF MEXICO AND ACROSS FLORIDA. LATEST MODEL GUIDANCE HAS
FLUCTUATED TO FAVORING A SURFACE LOW TRACK CLOSER TO THE COAST AND
TO THE LOCAL WATERS. IF THIS OCCURS...THE GRADIENT MAY ACTUALLY
RELAX AND RESULT IN WEAKER FLOW. HOWEVER...IF THE LOW REMAINS
FURTHER TO THE SOUTH...THE GRADIENT MAY ACTUALLY BE ENHANCED AND
RESULT IN THE POSSIBILITY OF GALE EVENT AND HIGH SURF FRIDAY NIGHT
THROUGH SATURDAY. FORECAST CONFIDENCE IS TOO LOW TO SAY WHICH
SCENARIO IS MORE LIKELY AT THIS POINT. THEREFORE...THE CURRENT SMALL
CRAFT ADVISORIES HAVE BEEN LEFT INTACT...AND SUBSEQUENT FORECAST
UPDATES WILL HAVE TO READDRESS THE POTENTIAL FOR THESE HAZARDS.
THERE IS BETTER CERTAINTY FOR THE LATE WEEKEND AND EARLY WEEK TIME
PERIOD WHEN THE LOW IS EXPECTED TO BE FAR ENOUGH EAST FOR ANOTHER
ROUND OF ENHANCED GRADIENT ACROSS THE WATERS. STRONG WINDS AND
ELEVATED SEAS APPEAR LIKELY SUNDAY INTO MONDAY.

RIP CURRENTS...A BIT OF AN UNDERLYING LONGER PERIOD SWELL NOTED FROM
FRYING PAN SHOALS TO GRAYS REEF OVERNIGHT WAS ENOUGH TO TIP OUR
MODERATE RISK TO A HIGH RISK FROM BEAUFORT COUNTY SOUTHWARD. A
MODERATE RISK FOR RIP CURRENTS CONTINUES FOR CHARLESTON BEACHES
TODAY WITH AN ENHANCED LONGSHORE CURRENT. AN ENHANCED RISK FOR RIP
CURRENTS WILL PERSIST THROUGH THE WEEKEND AND PERHAPS INTO EARLY
NEXT WEEK.

&&

.HYDROLOGY...
THE PROBABILITY OF A WIDESPREAD SIGNIFICANT RAINFALL EVENT IS
INCREASING FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
HEAVIEST RAIN IS EXPECTED TO OCCUR FRIDAY NIGHT THROUGH SATURDAY
MORNING. MODERATE TO OCCASIONALLY HEAVY RAIN IS LIKELY...AND TOTAL
RAINFALL AMOUNTS WILL GENERALLY RANGE FROM 1-3 INCHES. THE HIGHEST
AMOUNTS WILL OCCUR ALONG AND NEAR THE COAST...WITH SOME LOCALLY
GREATER TOTALS POSSIBLE. THIS RAINFALL MAY CAUSE FLOODING ISSUES
AROUND THE TIMES OF HIGH TIDE ALONG THE COAST INCLUDING DOWNTOWN
CHARLESTON AND SAVANNAH...AS WELL AS PONDING OF WATER ELSEWHERE
ESPECIALLY IN LOW LYING AND POOR DRAINAGE AREAS. ALSO...MAIN STEM
RIVERS AND ASSOCIATED TRIBUTARIES WILL LIKELY SEE RISES WITH THE
POTENTIAL FOR MINOR FLOODING DEPENDING ON OBSERVED RAINFALL AMOUNTS.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR
     GAZ117-119-139-141.
SC...HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR
     SCZ048-051.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT SUNDAY FOR AMZ350-352-354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ330.

&&

$$

SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...BSH
LONG TERM...BSH
AVIATION...RJB
MARINE...BSH/RJB
HYDROLOGY...
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 171457
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1057 AM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED WELL NORTH OF THE REGION WILL PERSIST THROUGH
TONIGHT...ALTHOUGH WILL BE SLOWLY WEAKENING WITH TIME. AN AREA OF
LOW PRESSURE WILL DEVELOP OVER THE NORTHEAST GULF OF MEXICO ON
FRIDAY. THIS LOW WILL THEN SLOWLY CROSS FLORIDA AND EVENTUALLY
MOVE OFF THE SOUTHEAST COAST BY THE LATTER PART OF THE WEEKEND.
HIGH PRESSURE WILL BUILD BACK IN EARLY NEXT WEEK. A WEAK COLD
FRONT MAY APPROACH THE AREA FROM THE NORTH BY MID WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...NO MAJOR CHANGES. STRONG HIGH PRESSURE WILL CONTINUE TO
RIDGE DOWN THE EAST COAST MAINTAINING DRY CONDITIONS. ANY SHOWERS
SHOULD REMAIN OVER THE ATLANTIC WHERE THE DEEPER MOISTURE IS
LOCATED. HIGHS WILL BE A WARMER THAN YESTERDAY BUT STILL BELOW
NORMAL...MAINLY MID TO UPPER 60S AWAY FROM THE LOCALLY COOLER
IMMEDIATE COAST. BREEZY CONDITIONS WILL HANG ON GIVEN THE PRESSURE
GRADIENT OVER THE AREA...WITH THE STRONGEST WINDS LIKELY NEAR THE
COAST WHERE GUSTS WILL BE AROUND 25 MPH AT TIMES. SKIES WILL
AVERAGE PARTLY TO MOSTLY CLOUDY.

TONIGHT...HIGH CLOUDS WILL THICKEN OVERNIGHT AHEAD OF A
DEVELOPING GULF COAST SYSTEM. INCREASING DYNAMICS AND MOISTURE
CONVERGENCE TO OUR SW WILL SPREAD RAINS INTO THE FLORIDA PANHANDLE
AND SW GEORGIA AFTER MIDNIGHT. THE RISK FOR WET WEATHER IS
EXPECTED TO HOLD OFF UNTIL TOWARD DAYBREAK ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. CLOUDS AND LINGERING NE WINDS SHOULD
KEEP TEMPS MILDER OVERNIGHT...RANGING FROM THE MID TO UPPER 40S NW
TIER TO LOWER/MID 50S ALONG THE COAST.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY THROUGH SATURDAY...CONFIDENCE HAS INCREASED SIGNIFICANTLY IN
AN ACTIVE AND VERY WET SCENARIO FOR THE FORECAST AREA. OTHER THAN
THE NAM...THE LATEST RUNS OF THE SUITE OF FORECAST MODELS HAVE
CONVERGED ON A SOLUTION THAT FAVORS A WIDESPREAD SIGNIFICANT
RAINFALL EVENT STRETCHING FROM THE FLORIDA PANHANDLE AND UP THE
GEORGIA/SOUTH CAROLINA COASTLINE. ON FRIDAY...A SOUTHERN STREAM
SHORTWAVE WILL CROSS THE LOWER MISSISSIPPI VALLEY AND INTENSIFY INTO
A CLOSED LOW ACROSS THE DEEP SOUTH. AN IMPRESSIVE DEGREE OF FORCING
WILL TAKE SHAPE WITH RIGHT ENTRANCE REGION UPPER JET
DYNAMICS...STRONG LOW/MID LEVEL FRONTOGENESIS...AND DEEP MOIST
CONVERGENCE ALL ALIGNING ACROSS THE REGION ESPECIALLY FRIDAY NIGHT.
FURTHERMORE...PWATS WILL SURGE TO IN EXCESS OF 1.75 INCHES WHICH
WOULD EXCEED THE 99TH PERCENTILE FOR MID APRIL. PRECIPITATION WILL
INVADE FROM THE SOUTH ON FRIDAY...BECOMING MOST WIDESPREAD FRIDAY
NIGHT. POPS HAVE BEEN ALTERED DRAMATICALLY AND NOW FEATURE NEAR 100
PERCENT CHANCES BY LATE FRIDAY NIGHT. GIVEN THE PRESENCE OF THE
STRONG FORCING AND VERY MOIST AIRMASS...WIDESPREAD MODERATE TO
OCCASIONALLY HEAVY RAIN WILL OCCUR JUST ABOUT EVERYWHERE. BY
SATURDAY MORNING...SOME MODEL SOLUTIONS INDICATE A HIGH PROBABILITY
OF WIDESPREAD RAINFALL AMOUNTS OF 3 OR MORE INCHES. POPS THEN
DECREASE FROM WEST TO EAST DURING THE DAY ON SATURDAY AS THE FORCING
SHIFTS OFFSHORE AND THE SLOW MOVING SURFACE LOW DRIFTS OFF THE
FLORIDA COASTLINE. OF LESSER IMPACT...THE MODELS INDICATE THE
PRESENCE OF A SLOT OF STEEPENING MID LEVEL LAPSE RATES AND NEGATIVE
SHOWALTER INDICES FRIDAY NIGHT. THIS MAY RESULT IN SOME ELEVATED
THUNDERSTORM ACTIVITY...BUT FOR NOW THE HIGHEST PROBABILITIES ARE
OVER THE ADJACENT COASTAL WATERS. THUNDER MAY EVENTUALLY NEED TO BE
ADDED TO INLAND AREAS. THE FORECAST AREA HAS BEEN ADDED TO THE DAY 2
EXCESSIVE RAINFALL OUTLOOK FROM WPC...BUT CURRENT THINKING IS THAT
WIDESPREAD FLASH FLOODING IS NOT EXPECTED SO NOTHING WILL BE ADDED
TO THE HWO. THIS THREAT WILL NEED TO BE REEVALUATED WITH FUTURE
FORECAST PACKAGES. TEMPERATURES WILL BE HELD DOWN BY THE WIDESPREAD
CLOUDS AND PRECIPITATION SO FRIDAY HIGHS WILL BE KEPT IN THE LOW
60S...AND SATURDAY HIGHS IN THE MID/UPPER 60S.

SUNDAY...CONDITIONS WILL INCREASE AS THE COLUMN DRIES OUT AND THE
SURFACE LOW MOVES FURTHER OFFSHORE. IN FACT LAND AREAS ARE EXPECTED
TO BE DRY WITH JUST LOW END CHANCES OVER THE COASTAL WATERS. WE MAY
HAVE TO DEAL WITH CONSIDERABLE WRAP AROUND CLOUDINESS WHICH MAY
NEGATIVELY IMPACT TEMPERATURES. FOR NOW...THE FORECAST FEATURES LOW
70S JUST ABOUT EVERYWHERE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
OVERALL THE LONG TERM PERIOD LOOKS QUIET FOR THE FORECAST AREA.
RIDGING ALOFT WILL MOVE IN FOR EARLY IN THE WEEK BEHIND THE
DEPARTING UPPER LOW. A WEAK TROUGH MAY MOVE THROUGH BY THE MID WEEK
TIME PERIOD. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH
TUESDAY...WITH A WEAK COLD FRONT ATTEMPTING TO CROSS BY WEDNESDAY.
THERE MAY BE A FEW SHOWERS WITH THE FRONT...BUT POPS HAVE BEEN
LIMITED TO THE SLIGHT CHANCE RANGE. TEMPERATURES FEATURE A WARMING
TREND...REACHING AROUND THE 80 DEGREE MARK BY TUESDAY AND CONTINUING
THROUGH THE END OF THE FORECAST PERIOD.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
KCHS...VFR CONDITIONS LIKELY TO PERSIST TODAY. STRATOCUMULUS
CLOUDINESS WILL INCREASE LATER TONIGHT BUT A BIT TOO EARLY TO
COMMIT TO ANY CIGS TO MVFR AT THIS STAGE. NE SURFACE WINDS WILL
BE GUSTY AT TIMES AGAIN TODAY WITH OCCASIONAL GUSTS AROUND 15 KT.
ELEVATED SURFACE WINDS 10 TO 15 KT LIKELY AGAIN LATE TONIGHT AS
THE GRADIENT TIGHTENS.

KSAV...BRIEF MVFR CIGS POSSIBLE THROUGH MID MORNING THEN MAINLY
VFR THROUGH LATE TONIGHT. MODELS SUGGEST MVFR CIGS POSSIBLE
BETWEEN 08Z-12Z FRIDAY BUT WILL ALLOW LATER CYCLES A CHANCE TO
PIN DOWN MVFR TIMING. NE SURFACE WINDS WILL BE GUSTY AT TIMES
AGAIN TODAY WITH OCCASIONAL GUSTS NEAR 25 KT POSSIBLE. ELEVATED
SURFACE WINDS 10 TO 15 KT LIKELY AGAIN LATE TONIGHT AS THE
GRADIENT TIGHTENS.

EXTENDED AVIATION OUTLOOK...CHANCES OF SUB-VFR CONDITIONS ARE
INCREASING...ESPECIALLY BEGINNING FRIDAY NIGHT. THESE CONDITIONS
WILL LIKELY PERSIST THROUGH SATURDAY...IMPROVING SUNDAY AND INTO
EARLY NEXT WEEK.

&&

.MARINE...
SOLID SMALL CRAFT ADVISORY CONDITIONS EXPECTED THROUGH TONIGHT AS
THE PRES GRADIENT REMAINS TIGHT BETWEEN HIGH PRES WEDGED DOWN THE
LEE OF THE MOUNTAINS AND DEVELOPING LOW PRES BY TONIGHT OVER
THE NE GULF OF MEXICO. MODELS SUGGEST THE ONGOING SURGE IN THE
20-25 KT WITH GUSTS TO 30 KT MAY EBB ALONG THE CHARLESTON COUNTY
COAST LATER TODAY AND THIS EVENING TO MORE OF A 15-20 KT FLOW
BUT THEN SURGE AGAIN AFTER MIDNIGHT FRIDAY MORNING. OVER GEORGIA
WATERS...NOT MUCH OF A LULL WITH THE STEADY NE FLOW THROUGH
TONIGHT WITH POTENTIAL FOR PINCHING TO PERSIST RIGHT ALONG COASTAL
BEAUFORT AND CHATHAM COUNTIES GIVEN THE ALIGNMENT OF THE ENHANCED
MOISTURE GRADIENTS. SEAS WILL REMAIN IN THE 5-8 FT RANGE WITHIN
20 NM AND UP TO 10 FT OFFSHORE CLOSER TO THE GULF STREAM INTO
TONIGHT.

FRIDAY THROUGH MONDAY...A STRONG NORTHEAST GRADIENT WILL PERSIST
THROUGH FRIDAY BETWEEN HIGH PRESSURE TO THE NORTH AND DEVELOPING LOW
PRESSURE TO THE SOUTH. FORECAST UNCERTAINTY THEN INCREASES FRIDAY
NIGHT ONWARD AS THE SURFACE LOW BEGINS TO MOVE OUT OF THE NORTHEAST
GULF OF MEXICO AND ACROSS FLORIDA. LATEST MODEL GUIDANCE HAS
FLUCTUATED TO FAVORING A SURFACE LOW TRACK CLOSER TO THE COAST AND
TO THE LOCAL WATERS. IF THIS OCCURS...THE GRADIENT MAY ACTUALLY
RELAX AND RESULT IN WEAKER FLOW. HOWEVER...IF THE LOW REMAINS
FURTHER TO THE SOUTH...THE GRADIENT MAY ACTUALLY BE ENHANCED AND
RESULT IN THE POSSIBILITY OF GALE EVENT AND HIGH SURF FRIDAY NIGHT
THROUGH SATURDAY. FORECAST CONFIDENCE IS TOO LOW TO SAY WHICH
SCENARIO IS MORE LIKELY AT THIS POINT. THEREFORE...THE CURRENT SMALL
CRAFT ADVISORIES HAVE BEEN LEFT INTACT...AND SUBSEQUENT FORECAST
UPDATES WILL HAVE TO READDRESS THE POTENTIAL FOR THESE HAZARDS.
THERE IS BETTER CERTAINTY FOR THE LATE WEEKEND AND EARLY WEEK TIME
PERIOD WHEN THE LOW IS EXPECTED TO BE FAR ENOUGH EAST FOR ANOTHER
ROUND OF ENHANCED GRADIENT ACROSS THE WATERS. STRONG WINDS AND
ELEVATED SEAS APPEAR LIKELY SUNDAY INTO MONDAY.

RIP CURRENTS...A BIT OF AN UNDERLYING LONGER PERIOD SWELL NOTED FROM
FRYING PAN SHOALS TO GRAYS REEF OVERNIGHT WAS ENOUGH TO TIP OUR
MODERATE RISK TO A HIGH RISK FROM BEAUFORT COUNTY SOUTHWARD. A
MODERATE RISK FOR RIP CURRENTS CONTINUES FOR CHARLESTON BEACHES
TODAY WITH AN ENHANCED LONGSHORE CURRENT. AN ENHANCED RISK FOR RIP
CURRENTS WILL PERSIST THROUGH THE WEEKEND AND PERHAPS INTO EARLY
NEXT WEEK.

&&

.HYDROLOGY...
THE PROBABILITY OF A WIDESPREAD SIGNIFICANT RAINFALL EVENT IS
INCREASING FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
HEAVIEST RAIN IS EXPECTED TO OCCUR FRIDAY NIGHT THROUGH SATURDAY
MORNING. MODERATE TO OCCASIONALLY HEAVY RAIN IS LIKELY...AND TOTAL
RAINFALL AMOUNTS WILL GENERALLY RANGE FROM 1-3 INCHES. THE HIGHEST
AMOUNTS WILL OCCUR ALONG AND NEAR THE COAST...WITH SOME LOCALLY
GREATER TOTALS POSSIBLE. THIS RAINFALL MAY CAUSE FLOODING ISSUES
AROUND THE TIMES OF HIGH TIDE ALONG THE COAST INCLUDING DOWNTOWN
CHARLESTON AND SAVANNAH...AS WELL AS PONDING OF WATER ELSEWHERE
ESPECIALLY IN LOW LYING AND POOR DRAINAGE AREAS. ALSO...MAIN STEM
RIVERS AND ASSOCIATED TRIBUTARIES WILL LIKELY SEE RISES WITH THE
POTENTIAL FOR MINOR FLOODING DEPENDING ON OBSERVED RAINFALL AMOUNTS.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR
     GAZ117-119-139-141.
SC...HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR
     SCZ048-051.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT SUNDAY FOR AMZ350-352-354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ330.

&&

$$

SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...BSH
LONG TERM...BSH
AVIATION...
MARINE...RJB/BSH
HYDROLOGY...
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 171138
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
738 AM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED WELL NORTH OF THE REGION WILL PERSIST THROUGH
TONIGHT. AN AREA OF LOW PRESSURE WILL DEVELOP OVER THE NORTHEAST GULF
OF MEXICO ON FRIDAY. THIS LOW WILL THEN SLOWLY CROSS FLORIDA AND
EVENTUALLY MOVE OFF THE SOUTHEAST COAST BY THE LATTER PART OF THE
WEEKEND. HIGH PRESSURE WILL BUILD BACK IN EARLY NEXT WEEK. A WEAK
COLD FRONT MAY APPROACH THE AREA FROM THE NORTH BY MID WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
STRONG HIGH PRES CENTERED OVER NORTHERN NEW ENGLAND WILL CONTINUE
TO WEDGE DOWN THE EASTERN SEABOARD INTO GEORGIA AND THE CAROLINAS
THROUGH TONIGHT. DRY WEATHER IS EXPECTED TO PERSIST OVER THE
FORECAST AREA TODAY AS ONLY A NARROW LAYER OF ATLC MOISTURE IS
NOTED UNDER A LARGE SUBSIDENCE INVERSION BETWEEN 4-7 KFT. BONE DRY
AIR NOTED IN THE MID LAYERS AND PWATS BELOW .7 INCHES. ALONG THE
GEORGIA BARRIER ISLANDS CLOSE TO THE ALTAMAHA...CANNOT COMPLETELY
RULE OUT A SPRINKLE BUT MEASURABLE PCPN CHANCES LOOK MINUTE. HIGHS
TODAY IN THE MID TO UPPER 60S...STILL WELL BELOW CLIMO. THE
BREEZES NOT EXPECTED TO ABATE WITH A TIGHT GRADIENT ACROSS MUCH OF
THE AREA AND DEEPER AFTERNOON MIXING PROFILES. SKY COVERAGE IS
QUITE CHALLENGING TODAY BUT GEORGIA ZONES APPEAR MOST LIKELY TO
SEE PERIODS OF CLOUDY SKIES AT TIMES.

TONIGHT...HIGH CLOUDS WILL THICKEN OVERNIGHT AHEAD OF A
DEVELOPING GULF COAST SYSTEM. INCREASING DYNAMICS AND MOISTURE
CONVERGENCE TO OUR SW WILL SPREAD RAINS INTO THE FLORIDA PANHANDLE
AND SW GEORGIA AFTER MIDNIGHT. THE RISK FOR WET WEATHER IS
EXPECTED TO HOLD OFF UNTIL TOWARD DAYBREAK ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. CLOUDS AND LINGERING NE WINDS SHOULD
KEEP TEMPS MILDER OVERNIGHT...RANGING FROM THE MID TO UPPER 40S NW
TIER TO LOWER/MID 50S ALONG THE COAST.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY THROUGH SATURDAY...CONFIDENCE HAS INCREASED SIGNIFICANTLY IN
AN ACTIVE AND VERY WET SCENARIO FOR THE FORECAST AREA. OTHER THAN
THE NAM...THE LATEST RUNS OF THE SUITE OF FORECAST MODELS HAVE
CONVERGED ON A SOLUTION THAT FAVORS A WIDESPREAD SIGNIFICANT
RAINFALL EVENT STRETCHING FROM THE FLORIDA PANHANDLE AND UP THE
GEORGIA/SOUTH CAROLINA COASTLINE. ON FRIDAY...A SOUTHERN STREAM
SHORTWAVE WILL CROSS THE LOWER MISSISSIPPI VALLEY AND INTENSIFY INTO
A CLOSED LOW ACROSS THE DEEP SOUTH. AN IMPRESSIVE DEGREE OF FORCING
WILL TAKE SHAPE WITH RIGHT ENTRANCE REGION UPPER JET
DYNAMICS...STRONG LOW/MID LEVEL FRONTOGENESIS...AND DEEP MOIST
CONVERGENCE ALL ALIGNING ACROSS THE REGION ESPECIALLY FRIDAY NIGHT.
FURTHERMORE...PWATS WILL SURGE TO IN EXCESS OF 1.75 INCHES WHICH
WOULD EXCEED THE 99TH PERCENTILE FOR MID APRIL. PRECIPITATION WILL
INVADE FROM THE SOUTH ON FRIDAY...BECOMING MOST WIDESPREAD FRIDAY
NIGHT. POPS HAVE BEEN ALTERED DRAMATICALLY AND NOW FEATURE NEAR 100
PERCENT CHANCES BY LATE FRIDAY NIGHT. GIVEN THE PRESENCE OF THE
STRONG FORCING AND VERY MOIST AIRMASS...WIDESPREAD MODERATE TO
OCCASIONALLY HEAVY RAIN WILL OCCUR JUST ABOUT EVERYWHERE. BY
SATURDAY MORNING...SOME MODEL SOLUTIONS INDICATE A HIGH PROBABILITY
OF WIDESPREAD RAINFALL AMOUNTS OF 3 OR MORE INCHES. POPS THEN
DECREASE FROM WEST TO EAST DURING THE DAY ON SATURDAY AS THE FORCING
SHIFTS OFFSHORE AND THE SLOW MOVING SURFACE LOW DRIFTS OFF THE
FLORIDA COASTLINE. OF LESSER IMPACT...THE MODELS INDICATE THE
PRESENCE OF A SLOT OF STEEPENING MID LEVEL LAPSE RATES AND NEGATIVE
SHOWALTER INDICES FRIDAY NIGHT. THIS MAY RESULT IN SOME ELEVATED
THUNDERSTORM ACTIVITY...BUT FOR NOW THE HIGHEST PROBABILITIES ARE
OVER THE ADJACENT COASTAL WATERS. THUNDER MAY EVENTUALLY NEED TO BE
ADDED TO INLAND AREAS. THE FORECAST AREA HAS BEEN ADDED TO THE DAY 2
EXCESSIVE RAINFALL OUTLOOK FROM WPC...BUT CURRENT THINKING IS THAT
WIDESPREAD FLASH FLOODING IS NOT EXPECTED SO NOTHING WILL BE ADDED
TO THE HWO. THIS THREAT WILL NEED TO BE REEVALUATED WITH FUTURE
FORECAST PACKAGES. TEMPERATURES WILL BE HELD DOWN BY THE WIDESPREAD
CLOUDS AND PRECIPITATION SO FRIDAY HIGHS WILL BE KEPT IN THE LOW
60S...AND SATURDAY HIGHS IN THE MID/UPPER 60S.

SUNDAY...CONDITIONS WILL INCREASE AS THE COLUMN DRIES OUT AND THE
SURFACE LOW MOVES FURTHER OFFSHORE. IN FACT LAND AREAS ARE EXPECTED
TO BE DRY WITH JUST LOW END CHANCES OVER THE COASTAL WATERS. WE MAY
HAVE TO DEAL WITH CONSIDERABLE WRAP AROUND CLOUDINESS WHICH MAY
NEGATIVELY IMPACT TEMPERATURES. FOR NOW...THE FORECAST FEATURES LOW
70S JUST ABOUT EVERYWHERE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
OVERALL THE LONG TERM PERIOD LOOKS QUIET FOR THE FORECAST AREA.
RIDGING ALOFT WILL MOVE IN FOR EARLY IN THE WEEK BEHIND THE
DEPARTING UPPER LOW. A WEAK TROUGH MAY MOVE THROUGH BY THE MID WEEK
TIME PERIOD. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH
TUESDAY...WITH A WEAK COLD FRONT ATTEMPTING TO CROSS BY WEDNESDAY.
THERE MAY BE A FEW SHOWERS WITH THE FRONT...BUT POPS HAVE BEEN
LIMITED TO THE SLIGHT CHANCE RANGE. TEMPERATURES FEATURE A WARMING
TREND...REACHING AROUND THE 80 DEGREE MARK BY TUESDAY AND CONTINUING
THROUGH THE END OF THE FORECAST PERIOD.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
KCHS...VFR CONDITIONS LIKELY TO PERSIST TODAY. STRATOCUMULUS
CLOUDINESS WILL INCREASE LATER TONIGHT BUT A BIT TOO EARLY TO
COMMIT TO ANY CIGS TO MVFR AT THIS STAGE. NE SURFACE WINDS WILL
BE GUSTY AT TIMES AGAIN TODAY WITH OCCASIONAL GUSTS OVER 20 KT.
ELEVATED SURFACE WINDS 10 TO 15 KT LIKELY AGAIN LATE TONIGHT
AS THE GRADIENT TIGHTENS.

KSAV...BRIEF MVFR CIGS POSSIBLE THROUGH MID MORNING THEN MAINLY
VFR THROUGH LATE TONIGHT. MODELS SUGGEST MVFR CIGS POSSIBLE
BETWEEN 08Z-12Z FRIDAY BUT WILL ALLOW LATER CYCLES A CHANCE TO
PIN DOWN MVFR TIMING. NE SURFACE WINDS WILL BE GUSTY AT TIMES
AGAIN TODAY WITH OCCASIONAL GUSTS NEAR 25 KT POSSIBLE. ELEVATED
SURFACE WINDS 10 TO 15 KT LIKELY AGAIN LATE TONIGHT AS THE
GRADIENT TIGHTENS.

EXTENDED AVIATION OUTLOOK...CHANCES OF SUB-VFR CONDITIONS ARE
INCREASING...ESPECIALLY BEGINNING FRIDAY NIGHT. THESE CONDITIONS
WILL LIKELY PERSIST THROUGH SATURDAY...IMPROVING SUNDAY AND INTO
EARLY NEXT WEEK.

&&

.MARINE...
SOLID SMALL CRAFT ADVISORY CONDITIONS EXPECTED THROUGH TONIGHT AS
THE PRES GRADIENT REMAINS TIGHT BETWEEN HIGH PRES WEDGED DOWN THE
LEE OF THE MOUNTAINS AND DEVELOPING LOW PRES BY TONIGHT OVER
THE NE GULF OF MEXICO. MODELS SUGGEST THE ONGOING SURGE IN THE
20-25 KT WITH GUSTS TO 30 KT MAY EBB ALONG THE CHARLESTON COUNTY
COAST LATER TODAY AND THIS EVENING TO MORE OF A 15-20 KT FLOW
BUT THEN SURGE AGAIN AFTER MIDNIGHT FRIDAY MORNING. OVER GEORGIA
WATERS...NOT MUCH OF A LULL WITH THE STEADY NE FLOW THROUGH
TONIGHT WITH POTENTIAL FOR PINCHING TO PERSIST RIGHT ALONG COASTAL
BEAUFORT AND CHATHAM COUNTIES GIVEN THE ALIGNMENT OF THE ENHANCED
MOISTURE GRADIENTS. SEAS WILL REMAIN IN THE 5-8 FT RANGE WITHIN
20 NM AND UP TO 10 FT OFFSHORE CLOSER TO THE GULF STREAM INTO
TONIGHT.

FRIDAY THROUGH MONDAY...A STRONG NORTHEAST GRADIENT WILL PERSIST
THROUGH FRIDAY BETWEEN HIGH PRESSURE TO THE NORTH AND DEVELOPING LOW
PRESSURE TO THE SOUTH. FORECAST UNCERTAINTY THEN INCREASES FRIDAY
NIGHT ONWARD AS THE SURFACE LOW BEGINS TO MOVE OUT OF THE NORTHEAST
GULF OF MEXICO AND ACROSS FLORIDA. LATEST MODEL GUIDANCE HAS
FLUCTUATED TO FAVORING A SURFACE LOW TRACK CLOSER TO THE COAST AND
TO THE LOCAL WATERS. IF THIS OCCURS...THE GRADIENT MAY ACTUALLY
RELAX AND RESULT IN WEAKER FLOW. HOWEVER...IF THE LOW REMAINS
FURTHER TO THE SOUTH...THE GRADIENT MAY ACTUALLY BE ENHANCED AND
RESULT IN THE POSSIBILITY OF GALE EVENT AND HIGH SURF FRIDAY NIGHT
THROUGH SATURDAY. FORECAST CONFIDENCE IS TOO LOW TO SAY WHICH
SCENARIO IS MORE LIKELY AT THIS POINT. THEREFORE...THE CURRENT SMALL
CRAFT ADVISORIES HAVE BEEN LEFT INTACT...AND SUBSEQUENT FORECAST
UPDATES WILL HAVE TO READDRESS THE POTENTIAL FOR THESE HAZARDS.
THERE IS BETTER CERTAINTY FOR THE LATE WEEKEND AND EARLY WEEK TIME
PERIOD WHEN THE LOW IS EXPECTED TO BE FAR ENOUGH EAST FOR ANOTHER
ROUND OF ENHANCED GRADIENT ACROSS THE WATERS. STRONG WINDS AND
ELEVATED SEAS APPEAR LIKELY SUNDAY INTO MONDAY.

RIP CURRENTS...A BIT OF AN UNDERLYING LONGER PERIOD SWELL NOTED FROM
FRYING PAN SHOALS TO GRAYS REEF OVERNIGHT WAS ENOUGH TO TIP OUR
MODERATE RISK TO A HIGH RISK FROM BEAUFORT COUNTY SOUTHWARD. A
MODERATE RISK FOR RIP CURRENTS CONTINUES FOR CHARLESTON BEACHES
TODAY WITH AN ENHANCED LONGSHORE CURRENT. AN ENHANCED RISK FOR RIP
CURRENTS WILL PERSIST THROUGH THE WEEKEND AND PERHAPS INTO EARLY
NEXT WEEK.

&&

.HYDROLOGY...
THE PROBABILITY OF A WIDESPREAD SIGNIFICANT RAINFALL EVENT IS
INCREASING FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
HEAVIEST RAIN IS EXPECTED TO OCCUR FRIDAY NIGHT THROUGH SATURDAY
MORNING. MODERATE TO OCCASIONALLY HEAVY RAIN IS LIKELY...AND TOTAL
RAINFALL AMOUNTS WILL GENERALLY RANGE FROM 1-3 INCHES. THE HIGHEST
AMOUNTS WILL OCCUR ALONG AND NEAR THE COAST...WITH SOME LOCALLY
GREATER TOTALS POSSIBLE. THIS RAINFALL MAY CAUSE FLOODING ISSUES
AROUND THE TIMES OF HIGH TIDE ALONG THE COAST INCLUDING DOWNTOWN
CHARLESTON AND SAVANNAH...AS WELL AS PONDING OF WATER ELSEWHERE
ESPECIALLY IN LOW LYING AND POOR DRAINAGE AREAS. ALSO...MAIN STEM
RIVERS AND ASSOCIATED TRIBUTARIES WILL LIKELY SEE RISES WITH THE
POTENTIAL FOR MINOR FLOODING DEPENDING ON OBSERVED RAINFALL AMOUNTS.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ330.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT SUNDAY FOR AMZ350-352-354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ374.

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...BSH
LONG TERM...BSH
AVIATION...
MARINE...BSH
HYDROLOGY...
TIDES/COASTAL FLOODING...








000
FXUS62 KCHS 170837
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
437 AM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED WELL NORTH OF THE REGION WILL PERSIST THROUGH
TONIGHT. AN AREA OF LOW PRESSURE WILL DEVELOP OVER THE NORTHEAST GULF
OF MEXICO ON FRIDAY. THIS LOW WILL THEN SLOWLY CROSS FLORIDA AND
EVENTUALLY MOVE OFF THE SOUTHEAST COAST BY THE LATTER PART OF THE
WEEKEND. HIGH PRESSURE WILL BUILD BACK IN EARLY NEXT WEEK. A WEAK
COLD FRONT MAY APPROACH THE AREA FROM THE NORTH BY MID WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...MOST AREAS HAVE BEEN IN THE 40S OVERNIGHT WITH MOST
INLAND OB SITES REPORTING 4-5 KT OF NE FLOW. ACROSS SE GEORGIA...
MILDER CONDITIONS TO THE WEST OF I-95 WITH EXPANSION OF STRATOCUMULUS
FIELDS NOTED ON OVERNIGHT 11-3.9 MICRON SATELLITE IMAGERY.

STRONG HIGH PRES CENTERED OVER NORTHERN NEW ENGLAND WILL CONTINUE
TO WEDGE DOWN THE EASTERN SEABOARD INTO GEORGIA AND THE CAROLINAS
THROUGH TONIGHT. DRY WEATHER IS EXPECTED TO PERSIST OVER THE
FORECAST AREA TODAY AS ONLY A NARROW LAYER OF ATLC MOISTURE IS
NOTED UNDER A LARGE SUBSIDENCE INVERSION BETWEEN 4-7 KFT. BONE DRY
AIR NOTED IN THE MID LAYERS AND PWATS BELOW .7 INCHES. ALONG THE
GEORGIA BARRIER ISLANDS CLOSE TO THE ALTAMAHA...CANNOT COMPLETELY
RULE OUT A SPRINKLE BUT MEASURABLE PCPN CHANCES LOOK MINUTE. HIGHS
TODAY IN THE MID TO UPPER 60S...STILL WELL BELOW CLIMO. THE BREEZES
NOT EXPECTED TO ABATE WITH A TIGHT GRADIENT ACROSS MUCH OF THE
AREA AND DEEPER AFTERNOON MIXING PROFILES. SKY COVERAGE IS QUITE
CHALLENGING TODAY BUT SOUTHERN ZONES APPEAR MOST LIKELY TO SEE
PERIODS OF MOSTLY CLOUDY SKIES AT TIMES.

TONIGHT...HIGH CLOUDS WILL THICKEN OVERNIGHT AHEAD OF A
DEVELOPING GULF COAST SYSTEM. INCREASING DYNAMICS AND MOISTURE
CONVERGENCE TO OUR SW WILL SPREAD RAINS INTO THE FLORIDA PANHANDLE
AND SW GEORGIA AFTER MIDNIGHT. THE RISK FOR WET WEATHER IS
EXPECTED TO HOLD OFF UNTIL TOWARD DAYBREAK ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. CLOUDS AND LINGERING NE WINDS SHOULD
KEEP TEMPS MILDER OVERNIGHT...RANGING FROM THE MID TO UPPER 40S NW
TIER TO LOWER/MID 50S ALONG THE COAST.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FRIDAY THROUGH SATURDAY...CONFIDENCE HAS INCREASED SIGNIFICANTLY IN
AN ACTIVE AND VERY WET SCENARIO FOR THE FORECAST AREA. OTHER THAN
THE NAM...THE LATEST RUNS OF THE SUITE OF FORECAST MODELS HAVE
CONVERGED ON A SOLUTION THAT FAVORS A WIDESPREAD SIGNIFICANT
RAINFALL EVENT STRETCHING FROM THE FLORIDA PANHANDLE AND UP THE
GEORGIA/SOUTH CAROLINA COASTLINE. ON FRIDAY...A SOUTHERN STREAM
SHORTWAVE WILL CROSS THE LOWER MISSISSIPPI VALLEY AND INTENSIFY INTO
A CLOSED LOW ACROSS THE DEEP SOUTH. AN IMPRESSIVE DEGREE OF FORCING
WILL TAKE SHAPE WITH RIGHT ENTRANCE REGION UPPER JET
DYNAMICS...STRONG LOW/MID LEVEL FRONTOGENESIS...AND DEEP MOIST
CONVERGENCE ALL ALIGNING ACROSS THE REGION ESPECIALLY FRIDAY NIGHT.
FURTHERMORE...PWATS WILL SURGE TO IN EXCESS OF 1.75 INCHES WHICH
WOULD EXCEED THE 99TH PERCENTILE FOR MID APRIL. PRECIPITATION WILL
INVADE FROM THE SOUTH ON FRIDAY...BECOMING MOST WIDESPREAD FRIDAY
NIGHT. POPS HAVE BEEN ALTERED DRAMATICALLY AND NOW FEATURE NEAR 100
PERCENT CHANCES BY LATE FRIDAY NIGHT. GIVEN THE PRESENCE OF THE
STRONG FORCING AND VERY MOIST AIRMASS...WIDESPREAD MODERATE TO
OCCASIONALLY HEAVY RAIN WILL OCCUR JUST ABOUT EVERYWHERE. BY
SATURDAY MORNING...SOME MODEL SOLUTIONS INDICATE A HIGH PROBABILITY
OF WIDESPREAD RAINFALL AMOUNTS OF 3 OR MORE INCHES. POPS THEN
DECREASE FROM WEST TO EAST DURING THE DAY ON SATURDAY AS THE FORCING
SHIFTS OFFSHORE AND THE SLOW MOVING SURFACE LOW DRIFTS OFF THE
FLORIDA COASTLINE. OF LESSER IMPACT...THE MODELS INDICATE THE
PRESENCE OF A SLOT OF STEEPENING MID LEVEL LAPSE RATES AND NEGATIVE
SHOWALTER INDICES FRIDAY NIGHT. THIS MAY RESULT IN SOME ELEVATED
THUNDERSTORM ACTIVITY...BUT FOR NOW THE HIGHEST PROBABILITIES ARE
OVER THE ADJACENT COASTAL WATERS. THUNDER MAY EVENTUALLY NEED TO BE
ADDED TO INLAND AREAS. THE FORECAST AREA HAS BEEN ADDED TO THE DAY 2
EXCESSIVE RAINFALL OUTLOOK FROM WPC...BUT CURRENT THINKING IS THAT
WIDESPREAD FLASH FLOODING IS NOT EXPECTED SO NOTHING WILL BE ADDED
TO THE HWO. THIS THREAT WILL NEED TO BE REEVALUATED WITH FUTURE
FORECAST PACKAGES. TEMPERATURES WILL BE HELD DOWN BY THE WIDESPREAD
CLOUDS AND PRECIPITATION SO FRIDAY HIGHS WILL BE KEPT IN THE LOW
60S...AND SATURDAY HIGHS IN THE MID/UPPER 60S.

SUNDAY...CONDITIONS WILL INCREASE AS THE COLUMN DRIES OUT AND THE
SURFACE LOW MOVES FURTHER OFFSHORE. IN FACT LAND AREAS ARE EXPECTED
TO BE DRY WITH JUST LOW END CHANCES OVER THE COASTAL WATERS. WE MAY
HAVE TO DEAL WITH CONSIDERABLE WRAP AROUND CLOUDINESS WHICH MAY
NEGATIVELY IMPACT TEMPERATURES. FOR NOW...THE FORECAST FEATURES LOW
70S JUST ABOUT EVERYWHERE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
OVERALL THE LONG TERM PERIOD LOOKS QUIET FOR THE FORECAST AREA.
RIDGING ALOFT WILL MOVE IN FOR EARLY IN THE WEEK BEHIND THE
DEPARTING UPPER LOW. A WEAK TROUGH MAY MOVE THROUGH BY THE MID WEEK
TIME PERIOD. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION THROUGH
TUESDAY...WITH A WEAK COLD FRONT ATTEMPTING TO CROSS BY WEDNESDAY.
THERE MAY BE A FEW SHOWERS WITH THE FRONT...BUT POPS HAVE BEEN
LIMITED TO THE SLIGHT CHANCE RANGE. TEMPERATURES FEATURE A WARMING
TREND...REACHING AROUND THE 80 DEGREE MARK BY TUESDAY AND CONTINUING
THROUGH THE END OF THE FORECAST PERIOD.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
KCHS SHOULD REMAIN VFR THROUGH 06Z FRIDAY. KSAV HAS SEEN SOME
MVFR CIGS DEVELOP THIS MORNING AND PATCHY CIGS 2500-3000 FT POSSIBLE
INTO MID MORNING. BREEZY CONDITIONS WILL DEVELOP LATER THIS
MORNING AS A TIGHT PRES GRADIENT RESIDES ALONG THE COASTAL
CORRIDOR. AREAS OF STRATOCU CIGS EXPECTED TO BE TRANSIENT RATHER
THAN WIDESPREAD TODAY. THICKER HIGH LEVEL CLOUDS WILL ALSO BE
INCREASING LATE TODAY AND THIS EVENING.

EXTENDED AVIATION OUTLOOK...CHANCES OF SUB-VFR CONDITIONS ARE
INCREASING...ESPECIALLY BEGINNING FRIDAY NIGHT. THESE CONDITIONS
WILL LIKELY PERSIST THROUGH SATURDAY...IMPROVING SUNDAY AND INTO
EARLY NEXT WEEK.

&&

.MARINE...
SOLID SMALL CRAFT ADVISORY CONDITIONS EXPECTED THROUGH TONIGHT AS
THE PRES GRADIENT REMAINS TIGHT BETWEEN HIGH PRES WEDGED DOWN THE
LEE OF THE MOUNTAINS AND DEVELOPING LOW PRES BY TONIGHT OVER
THE NE GULF OF MEXICO. MODELS SUGGEST THE ONGOING SURGE IN THE
20-25 KT WITH GUSTS TO 30 KT MAY EBB ALONG THE CHARLESTON COUNTY
COAST LATER TODAY AND THIS EVENING TO MORE OF A 15-20 KT FLOW
BUT THEN SURGE AGAIN AFTER MIDNIGHT FRIDAY MORNING. OVER GEORGIA
WATERS...NOT MUCH OF A LULL WITH THE STEADY NE FLOW THROUGH
TONIGHT WITH POTENTIAL FOR PINCHING TO PERSIST RIGHT ALONG COASTAL
BEAUFORT AND CHATHAM COUNTIES GIVEN THE ALIGNMENT OF THE ENHANCED
MOISTURE GRADIENTS. SEAS WILL REMAIN IN THE 5-8 FT RANGE WITHIN
20 NM AND UP TO 10 FT OFFSHORE CLOSER TO THE GULF STREAM INTO
TONIGHT.

FRIDAY THROUGH MONDAY...A STRONG NORTHEAST GRADIENT WILL PERSIST
THROUGH FRIDAY BETWEEN HIGH PRESSURE TO THE NORTH AND DEVELOPING LOW
PRESSURE TO THE SOUTH. FORECAST UNCERTAINTY THEN INCREASES FRIDAY
NIGHT ONWARD AS THE SURFACE LOW BEGINS TO MOVE OUT OF THE NORTHEAST
GULF OF MEXICO AND ACROSS FLORIDA. LATEST MODEL GUIDANCE HAS
FLUCTUATED TO FAVORING A SURFACE LOW TRACK CLOSER TO THE COAST AND
TO THE LOCAL WATERS. IF THIS OCCURS...THE GRADIENT MAY ACTUALLY
RELAX AND RESULT IN WEAKER FLOW. HOWEVER...IF THE LOW REMAINS
FURTHER TO THE SOUTH...THE GRADIENT MAY ACTUALLY BE ENHANCED AND
RESULT IN THE POSSIBILITY OF GALE EVENT AND HIGH SURF FRIDAY NIGHT
THROUGH SATURDAY. FORECAST CONFIDENCE IS TOO LOW TO SAY WHICH
SCENARIO IS MORE LIKELY AT THIS POINT. THEREFORE...THE CURRENT SMALL
CRAFT ADVISORIES HAVE BEEN LEFT INTACT...AND SUBSEQUENT FORECAST
UPDATES WILL HAVE TO READDRESS THE POTENTIAL FOR THESE HAZARDS.
THERE IS BETTER CERTAINTY FOR THE LATE WEEKEND AND EARLY WEEK TIME
PERIOD WHEN THE LOW IS EXPECTED TO BE FAR ENOUGH EAST FOR ANOTHER
ROUND OF ENHANCED GRADIENT ACROSS THE WATERS. STRONG WINDS AND
ELEVATED SEAS APPEAR LIKELY SUNDAY INTO MONDAY.

RIP CURRENTS...A BIT OF AN UNDERLYING LONGER PERIOD SWELL NOTED FROM
FRYING PAN SHOALS TO GRAYS REEF OVERNIGHT WAS ENOUGH TO TIP OUR
MODERATE RISK TO A HIGH RISK FROM BEAUFORT COUNTY SOUTHWARD. A
MODERATE RISK FOR RIP CURRENTS CONTINUES FOR CHARLESTON BEACHES
TODAY WITH AN ENHANCED LONGSHORE CURRENT. AN ENHANCED RISK FOR RIP
CURRENTS WILL PERSIST THROUGH THE WEEKEND AND PERHAPS INTO EARLY
NEXT WEEK.

&&

.HYDROLOGY...
THE PROBABILITY OF A WIDESPREAD SIGNIFICANT RAINFALL EVENT IS
INCREASING FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
HEAVIEST RAIN IS EXPECTED TO OCCUR FRIDAY NIGHT THROUGH SATURDAY
MORNING. MODERATE TO OCCASIONALLY HEAVY RAIN IS LIKELY...AND TOTAL
RAINFALL AMOUNTS WILL GENERALLY RANGE FROM 1-3 INCHES. THE HIGHEST
AMOUNTS WILL OCCUR ALONG AND NEAR THE COAST...WITH SOME LOCALLY
GREATER TOTALS POSSIBLE. THIS RAINFALL MAY CAUSE FLOODING ISSUES
AROUND THE TIMES OF HIGH TIDE ALONG THE COAST INCLUDING DOWNTOWN
CHARLESTON AND SAVANNAH...AS WELL AS PONDING OF WATER ELSEWHERE
ESPECIALLY IN LOW LYING AND POOR DRAINAGE AREAS. ALSO...MAIN STEM
RIVERS AND ASSOCIATED TRIBUTARIES WILL LIKELY SEE RISES WITH THE
POTENTIAL FOR MINOR FLOODING DEPENDING ON OBSERVED RAINFALL AMOUNTS.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ330.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT SUNDAY FOR AMZ350-352-354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ374.

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...BSH
LONG TERM...BSH
AVIATION...
MARINE...BSH
TIDES/COASTAL FLOODING...
HYDROLOGY...BSH







000
FXUS62 KCHS 170530
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
130 AM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF THE REGION THROUGH TONIGHT.
AN AREA OF LOW PRESSURE MAY AFFECT THE REGION FRIDAY AND SATURDAY
AS IT PASSES BY TO THE EAST OVER THE ATLANTIC. HIGH PRESSURE WILL
THEN RETURN TO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE HIGH PRESSURE WEDGE WILL STRENGTHEN OVERNIGHT AS THE CENTER OF
THE PARENT HIGH SHIFTS INTO THE NORTHEAST STATES. MODELS SHOW
MEAGER 290K ISENTROPIC LIFT DEVELOPING FROM MIDNIGHT ON. DESPITE
THE UPTICK IN ASSENT...CONDENSATION PRESSURE DEFICITS LOOK TO
REMAIN ABOVE 100 MB UNTIL EARLY THURSDAY MORNING...WHERE VALUES
DROP BELOW 50 NM ACROSS THE FAR SOUTH A FEW HOURS BEFORE SUNRISE.
THIS WILL RESULT IN A CLEAR CONDITIONS ACROSS THE ENTIRE AREA FOR
MUCH OF THE NIGHT WITH CLOUDS SLOWLY CREEPING INLAND FROM
SOUTHEAST TO NORTHWEST ROUGHLY BETWEEN 3 AM AND SUNRISE. HAVE
ADJUSTED THE GRIDDED SKY FORECASTS TO MATCH EXPECTED
TRENDS...DEPICTING MOSTLY CLEAR WELL INLAND THROUGH 12Z WITH SKIES
BECOMING PARTLY CLOUDY IN SOME AREAS ALONG THE SOUTH CAROLINA
COAST AND MOSTLY CLOUDY ROUGHLY ALONG AND SOUTH OF I-16.

FULL DECOUPLING OF THE BOUNDARY LAYER LOOKS DOUBTFUL TONIGHT GIVEN
THE TIGHTENING PRESSURE GRADIENT. THIS WILL HELP KEEP TEMPERATURES
UP DESPITE THE LACK OF SIGNIFICANT CLOUD COVER...ESPECIALLY ACROSS
THE FAR SOUTHERN AREAS. VERY LITTLE CHANGE ON THE RECENT PRODUCT
UPDATES TO LOW TEMPS AND HOURLY TRENDS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
A LOW-LEVEL RIDGE WILL REMAIN WEDGED DOWN THE EASTERN SEABOARD ON
THURSDAY BUT WILL BE GRADUALLY RETREATING IN RESPONSE TO A DIGGING
UPPER TROUGH FROM THE WEST. MOSTLY SUNNY SKIES WILL PREVAIL IN THE
MORNING...BEFORE CIRRUS STARTS TO INCREASE IN RESPONSE TO A
STRENGTHENING UPPER JET STREAM ACROSS THE SOUTHEAST UNITED STATES.
SCATTERED AFTERNOON CUMULUS IS ALSO POSSIBLE. AS LOW-LEVEL
THICKNESSES WARM...TEMPS SHOULD RESPOND BY RISING INTO THE UPPER 60S
TO AROUND 70.

UPPER VORT ENERGY DEVELOPS THURSDAY NIGHT INTO FRIDAY WITH A SURFACE
LOW FORMING ALONG THE CENTRAL GULF COAST REGION. DEEP LAYERED
MOISTURE WILL INCREASE OVER THE AREA WITH SOME WEAK ISENTROPIC
ASCENT PRODUCING SCATTERED SHOWERS BY DAYBREAK FRIDAY ACROSS
SOUTHERN AREAS. EXTENSIVE CLOUD COVER WILL KEEP HIGHS IN THE
MID/UPPER 60S FRIDAY.

THERE REMAIN MODEL DIFFERENCES REGARDING THE EVENTUAL TRACK OF THE
SURFACE LOW FRIDAY NIGHT AND SATURDAY. THE GFS AND NAM CONTINUE TO
BE THE DRY OUTLIERS WHILE THE CANADIAN AND ECMWF REMAIN QUITE WET
WITH A MORE WESTERN LOW TRACK. WE MAINTAINED SIMILAR POPS TO THE
PREVIOUS PACKAGE BUT INCREASED VALUES A BIT...MAINLY FRIDAY NIGHT
WHEN THE SYSTEM WILL MAKE ITS CLOSEST PASS. THE GREATEST COVERAGE OF
PRECIPITATION WOULD CERTAINLY BE OVER OUR COASTAL WATERS BUT THE
INLAND EXTENT IS QUITE UNCERTAIN AT THIS POINT.

HIGH TEMPS ON SATURDAY WILL REALLY DEPEND ON AMOUNT OF CLOUD COVER
AND WHETHER PRECIPITATION LINGERS AS THE ECMWF CURRENTLY SHOWS. FOR
NOW WE ARE SHOWING HIGHS IN THE MIDDLE 70S...A FEW DEGREES BELOW
CLIMO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EARLY IN THE PERIOD THERE IS STILL CONSIDERABLE UNCERTAINTY
REGARDING THE SURFACE LOW OFF THE FLORIDA COAST. THE DEEPER MODEL
SOLUTIONS KEEP THE LOW LINGERING AROUND WITH RAIN STILL ONGOING
ALONG THE SOUTHEAST COAST. BY MONDAY OR MONDAY NIGHT...THE LOW IS
EXPECTED TO PULL AWAY AND HIGH PRESSURE WILL RETURN TO THE REGION. A
COLD FRONT MAY ATTEMPT TO SAG IN FROM THE NORTH LATE IN THE PERIOD
WITH SOME MODEST INCREASE IN RAIN CHANCES. OVERALL...TEMPERATURES
ARE EXPECTED TO BE RIGHT AROUND CLIMO...ESPECIALLY BY THE MIDDLE OF
NEXT WEEK.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
MAINLY VFR. LOW PROBABILITIES FOR MVFR CIGS AT BOTH TERMINALS
09-12Z...BUT CONFIDENCE IS NOT HIGH ENOUGH AT THIS JUNCTURE TO
INCLUDE A MENTION. BREEZY CONDITIONS WILL DEVELOP TONIGHT AS
A TIGHT PRES GRADIENT RESIDES ALONG THE COASTAL CORRIDOR. AREAS
OF STRATOCU CIGS EXPECTED TO BE TRANSIENT RATHER THAN WIDESPREAD
TODAY. THICKER HIGH LEVEL CLOUDS WILL ALSO BE INCREASING LATE
TODAY AND THIS EVENING.

EXTENDED AVIATION OUTLOOK...LOW CHANCES FOR PERIODIC SUB-VFR
CONDITIONS LATE THURSDAY NIGHT/FRIDAY AS MARINE STRATOCUMULUS
ATTEMPT TO MOVE ONSHORE. BETTER CHANCES FOR FLIGHT RESTRICTIONS
WILL OCCUR FRIDAY NIGHT INTO SATURDAY AS LOW PRESSURE MOVES OUT OF
THE GULF OF MEXICO AND UP THE SOUTHEAST COAST.

&&

.MARINE...
OVERNIGHT....HIGH PRESSURE WILL STRENGTHEN TO THE NORTH TONIGHT
PRODUCING AN ENHANCED GRADIENT ACROSS THE LOCAL WATERS. THIS MEANS
WINDS WILL INCREASE OVERNIGHT WITH GUSTS NEAR 30 KT AT TIMES...
ESPECIALLY OUTSIDE CHARLESTON HARBOR. SEAS MOSTLY 5 TO 7 FT NEAR
SHORE AND UP TO 9 FT CLOSER TO THE GULF STREAM.

THURSDAY THROUGH SUNDAY...A STRONG RIDGE OF HIGH PRESSURE WILL
REMAIN NORTH OF THE WATERS THROUGH THURSDAY NIGHT BEFORE A GULF
LOW PRESSURE SYSTEM STARTS TAKING SHAPE TO THE SOUTH. THERE ARE
CONSIDERABLE MODEL DIFFERENCES REGARDING THE EVENTUAL TRACK OF THE
LOW...BUT IT WILL AT LEAST INDIRECTLY AFFECT OUR WATERS AS IT
LIFTS NORTHEAST. THE BOTTOM LINE IS THAT A PERSISTENT NORTHEAST
FETCH WITH SOLID SMALL CRAFT ADVISORY WINDS AND/OR SEAS WILL
CONTINUE THROUGH MUCH OF THE UPCOMING WEEKEND. SCA CONDITIONS WILL
LIKELY PERSIST OVER THE OFFSHORE GA WATERS INTO MIDDAY MONDAY DUE
TO LINGERING SEAS.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS CONTINUES INTO
THURSDAY DUE TO PERSISTENT SWELL...LINGERING ASTRONOMICAL INFLUENCES
AND GUSTY ONSHORE WINDS. AN ENHANCED RISK MAY PERSIST INTO THE EARLY
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR AMZ330.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT SUNDAY FOR AMZ350-352-354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ374.

&&

$$

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








000
FXUS62 KCHS 170124
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
924 PM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF THE REGION THROUGH THURSDAY NIGHT.
AN AREA OF LOW PRESSURE MAY AFFECT THE REGION FRIDAY AND SATURDAY
AS IT PASSES BY TO THE EAST OVER THE ATLANTIC. HIGH PRESSURE WILL
THEN RETURN TO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE FORECAST IS ON TRACK. ONLY MINOR ADJUSTMENTS TO HOURLY
PARAMETERS THROUGH MIDNIGHT WERE MADE.

THE HIGH PRESSURE WEDGE WILL STRENGTHEN TONIGHT AS THE CENTER OF
THE PARENT HIGH SHIFTS INTO THE NORTHEAST STATES. MODELS SHOW
MEAGER 290K ISENTROPIC LIFT DEVELOPING FROM MIDNIGHT ON. DESPITE
THE UPTICK IN ASSENT...CONDENSATION PRESSURE DEFICITS LOOK TO
REMAIN ABOVE 100 MB UNTIL EARLY THURSDAY MORNING...WHERE VALUES
DROP BELOW 50 NM ACROSS THE FAR SOUTH A FEW HOURS BEFORE SUNRISE.
THIS WILL RESULT IN A CLEAR CONDITIONS ACROSS THE ENTIRE AREA FOR
MUCH OF THE NIGHT WITH CLOUDS SLOWLY CREEPING INLAND FROM
SOUTHEAST TO NORTHWEST ROUGHLY BETWEEN 3 AM AND SUNRISE. HAVE
ADJUSTED THE GRIDDED SKY FORECASTS TO MATCH EXPECTED
TRENDS...DEPICTING MOSTLY CLEAR WELL INLAND THROUGH 12Z WITH
SKIES BECOMING PARTLY CLOUDY ALONG THE SOUTH CAROLINA COAST AND
MOSTLY CLOUDY ROUGHLY ALONG AND SOUTH OF I-16.

FULL DECOUPLING OF THE BOUNDARY LAYER LOOKS DOUBTFUL TONIGHT GIVEN
THE TIGHTENING PRESSURE GRADIENT. THIS WILL HELP KEEP TEMPERATURES
UP DESPITE THE LACK OF SIGNIFICANT CLOUD COVER...ESPECIALLY ACROSS
THE FAR SOUTHERN AREAS. OPTED TO NUDGE OVERNIGHT LOWS UP A FEW
DEGREES FOR MOST AREAS PER 18Z GUIDANCE AND PATTERN RECOGNITION.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
A LOW-LEVEL RIDGE WILL REMAIN WEDGED DOWN THE EASTERN SEABOARD ON
THURSDAY BUT WILL BE GRADUALLY RETREATING IN RESPONSE TO A DIGGING
UPPER TROUGH FROM THE WEST. MOSTLY SUNNY SKIES WILL PREVAIL IN THE
MORNING...BEFORE CIRRUS STARTS TO INCREASE IN RESPONSE TO A
STRENGTHENING UPPER JET STREAM ACROSS THE SOUTHEAST UNITED STATES.
SCATTERED AFTERNOON CUMULUS IS ALSO POSSIBLE. AS LOW-LEVEL
THICKNESSES WARM...TEMPS SHOULD RESPOND BY RISING INTO THE UPPER 60S
TO AROUND 70.

UPPER VORT ENERGY DEVELOPS THURSDAY NIGHT INTO FRIDAY WITH A SURFACE
LOW FORMING ALONG THE CENTRAL GULF COAST REGION. DEEP LAYERED
MOISTURE WILL INCREASE OVER THE AREA WITH SOME WEAK ISENTROPIC
ASCENT PRODUCING SCATTERED SHOWERS BY DAYBREAK FRIDAY ACROSS
SOUTHERN AREAS. EXTENSIVE CLOUD COVER WILL KEEP HIGHS IN THE
MID/UPPER 60S FRIDAY.

THERE REMAIN MODEL DIFFERENCES REGARDING THE EVENTUAL TRACK OF THE
SURFACE LOW FRIDAY NIGHT AND SATURDAY. THE GFS AND NAM CONTINUE TO
BE THE DRY OUTLIERS WHILE THE CANADIAN AND ECMWF REMAIN QUITE WET
WITH A MORE WESTERN LOW TRACK. WE MAINTAINED SIMILAR POPS TO THE
PREVIOUS PACKAGE BUT INCREASED VALUES A BIT...MAINLY FRIDAY NIGHT
WHEN THE SYSTEM WILL MAKE ITS CLOSEST PASS. THE GREATEST COVERAGE OF
PRECIPITATION WOULD CERTAINLY BE OVER OUR COASTAL WATERS BUT THE
INLAND EXTENT IS QUITE UNCERTAIN AT THIS POINT.

HIGH TEMPS ON SATURDAY WILL REALLY DEPEND ON AMOUNT OF CLOUD COVER
AND WHETHER PRECIPITATION LINGERS AS THE ECMWF CURRENTLY SHOWS. FOR
NOW WE ARE SHOWING HIGHS IN THE MIDDLE 70S...A FEW DEGREES BELOW
CLIMO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EARLY IN THE PERIOD THERE IS STILL CONSIDERABLE UNCERTAINTY
REGARDING THE SURFACE LOW OFF THE FLORIDA COAST. THE DEEPER MODEL
SOLUTIONS KEEP THE LOW LINGERING AROUND WITH RAIN STILL ONGOING
ALONG THE SOUTHEAST COAST. BY MONDAY OR MONDAY NIGHT...THE LOW IS
EXPECTED TO PULL AWAY AND HIGH PRESSURE WILL RETURN TO THE REGION. A
COLD FRONT MAY ATTEMPT TO SAG IN FROM THE NORTH LATE IN THE PERIOD
WITH SOME MODEST INCREASE IN RAIN CHANCES. OVERALL...TEMPERATURES
ARE EXPECTED TO BE RIGHT AROUND CLIMO...ESPECIALLY BY THE MIDDLE OF
NEXT WEEK.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
MAINLY VFR. MID-LEVEL CLOUDS WILL INCREASE AFTER 06Z...MAINLY
ACROSS THE SOUTH. LOW PROBABILITIES FOR MVFR CIGS AT BOTH
TERMINALS 09-12Z...BUT CONFIDENCE IS NOT HIGH ENOUGH AT THIS
JUNCTURE TO INCLUDE A MENTION. CAPPED CIGS AT BKN040-050 AT KSAV
AND OPTED NOT TO ESTABLISH CIGS AT KCHS DURING THE ENTIRE TAF
PERIOD.

EXTENDED AVIATION OUTLOOK...LOW CHANCES FOR PERIODIC SUB-VFR
CONDITIONS LATE THURSDAY NIGHT/FRIDAY AS MARINE STRATOCUMULUS
ATTEMPT TO MOVE ONSHORE. BETTER CHANCES FOR FLIGHT RESTRICTIONS
WILL OCCUR FRIDAY NIGHT INTO SATURDAY AS LOW PRESSURE MOVES OUT OF
THE GULF OF MEXICO AND UP THE SOUTHEAST COAST.

&&

.MARINE...
TONIGHT....HIGH PRESSURE WILL STRENGTHEN TO THE NORTH TONIGHT
PRODUCING AN ENHANCED GRADIENT ACROSS THE LOCAL WATERS. THIS MEANS
WINDS WILL INCREASE OVERNIGHT WITH GUSTS NEAR 30 KT AT TIMES...
ESPECIALLY OUTSIDE CHARLESTON HARBOR. SEAS MOSTLY 5 TO 7 FT NEAR
SHORE AND UP TO 9 FT CLOSER TO THE GULF STREAM.

THURSDAY THROUGH SUNDAY...A STRONG RIDGE OF HIGH PRESSURE WILL
REMAIN NORTH OF THE WATERS THROUGH THURSDAY NIGHT BEFORE A GULF
LOW PRESSURE SYSTEM STARTS TAKING SHAPE TO THE SOUTH. THERE ARE
CONSIDERABLE MODEL DIFFERENCES REGARDING THE EVENTUAL TRACK OF THE
LOW...BUT IT WILL AT LEAST INDIRECTLY AFFECT OUR WATERS AS IT
LIFTS NORTHEAST. THE BOTTOM LINE IS THAT A PERSISTENT NORTHEAST
FETCH WITH SOLID SMALL CRAFT ADVISORY WINDS AND/OR SEAS WILL
CONTINUE THROUGH MUCH OF THE UPCOMING WEEKEND. SCA CONDITIONS WILL
LIKELY PERSIST OVER THE OFFSHORE GA WATERS INTO MIDDAY MONDAY DUE
TO LINGERING SEAS.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS CONTINUES INTO
THURSDAY DUE TO PERSISTENT SWELL...LINGERING ASTRONOMICAL INFLUENCES
AND GUSTY ONSHORE WINDS. AN ENHANCED RISK MAY PERSIST INTO THE EARLY
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
CURRENT TIDE TRENDS SUGGEST TIDE LEVELS WILL PEAK JUST UNDER 7.0
FT MLLW IN THE CHARLESTON HARBOR WITH HIGH TIDE THIS EVENING.
HOWEVER...STEADY AND PERSISTENT NORTHEAST WINDS WILL LIKELY CAUSE A
FEW PROBLEMS IN DOWNTOWN CHARLESTON DUE TO ONGOING TIDAL LOADING...
DESPITE TIDES OF 6.7-6.9 FT MLLW. WILL ISSUE A COASTAL FLOOD
STATEMENT FOR CHARLESTON COUNTY TO HIGHLIGHT MINOR IMPACTS IN
DOWNTOWN CHARLESTON...MAINLY IN THE NORMAL FLOOD PRONE AREAS. TIDE
TRENDS WILL CONTINUE TO BE MONITORED OVER THE NEXT FEW HOURS AND
THE NEED FOR A COASTAL FLOOD ADVISORY FOR PARTS OF THE LOWER SOUTH
CAROLINA COAST HAS NOT BEEN COMPLETELY RULED OUT.

TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT SUNDAY FOR AMZ350-352-354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ374.

&&

$$

ST







000
FXUS62 KCHS 162237
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
637 PM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF THE REGION THROUGH THURSDAY NIGHT.
AN AREA OF LOW PRESSURE MAY AFFECT THE REGION FRIDAY AND SATURDAY
AS IT PASSES BY TO THE EAST OVER THE ATLANTIC. HIGH PRESSURE WILL
THEN RETURN TO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE HIGH PRESSURE WEDGE WILL STRENGTHEN TONIGHT AS THE CENTER OF
THE PARENT HIGH SHIFTS INTO THE NORTHEAST STATES. MODELS SHOW
MEAGER 290K ISENTROPIC LIFT DEVELOPING FROM MIDNIGHT ON. DESPITE
THE UPTICK IN ASSENT...CONDENSATION PRESSURE DEFICITS LOOK TO
REMAIN ABOVE 100 MB UNTIL EARLY THURSDAY MORNING...WHERE VALUES
DROP BELOW 50 NM ACROSS THE FAR SOUTH A FEW HOURS BEFORE SUNRISE.
THIS WILL RESULT IN A CLEAR CONDITIONS ACROSS THE ENTIRE AREA FOR
MUCH OF THE NIGHT WITH CLOUDS SLOWLY CREEPING INLAND FROM
SOUTHEAST TO NORTHWEST ROUGHLY BETWEEN 3 AM AND SUNRISE. HAVE
ADJUSTED THE GRIDDED SKY FORECASTS TO MATCH EXPECTED
TRENDS...DEPICTING MOSTLY CLEAR WELL INLAND THROUGH 12Z WITH
SKIES BECOMING PARTLY CLOUDY ALONG THE SOUTH CAROLINA COAST AND
MOSTLY CLOUDY ROUGHLY ALONG AND SOUTH OF I-16.

FULL DECOUPLING OF THE BOUNDARY LAYER LOOKS DOUBTFUL TONIGHT GIVEN
THE TIGHTENING PRESSURE GRADIENT. THIS WILL HELP KEEP TEMPERATURES
UP DESPITE THE LACK OF SIGNIFICANT CLOUD COVER...ESPECIALLY ACROSS
THE FAR SOUTHERN AREAS. OPTED TO NUDGE OVERNIGHT LOWS UP A FEW
DEGREES FOR MOST AREAS PER 18Z GUIDANCE AND PATTERN RECOGNITION.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
A LOW-LEVEL RIDGE WILL REMAIN WEDGED DOWN THE EASTERN SEABOARD ON
THURSDAY BUT WILL BE GRADUALLY RETREATING IN RESPONSE TO A DIGGING
UPPER TROUGH FROM THE WEST. MOSTLY SUNNY SKIES WILL PREVAIL IN THE
MORNING...BEFORE CIRRUS STARTS TO INCREASE IN RESPONSE TO A
STRENGTHENING UPPER JET STREAM ACROSS THE SOUTHEAST UNITED STATES.
SCATTERED AFTERNOON CUMULUS IS ALSO POSSIBLE. AS LOW-LEVEL
THICKNESSES WARM...TEMPS SHOULD RESPOND BY RISING INTO THE UPPER 60S
TO AROUND 70.

UPPER VORT ENERGY DEVELOPS THURSDAY NIGHT INTO FRIDAY WITH A SURFACE
LOW FORMING ALONG THE CENTRAL GULF COAST REGION. DEEP LAYERED
MOISTURE WILL INCREASE OVER THE AREA WITH SOME WEAK ISENTROPIC
ASCENT PRODUCING SCATTERED SHOWERS BY DAYBREAK FRIDAY ACROSS
SOUTHERN AREAS. EXTENSIVE CLOUD COVER WILL KEEP HIGHS IN THE
MID/UPPER 60S FRIDAY.

THERE REMAIN MODEL DIFFERENCES REGARDING THE EVENTUAL TRACK OF THE
SURFACE LOW FRIDAY NIGHT AND SATURDAY. THE GFS AND NAM CONTINUE TO
BE THE DRY OUTLIERS WHILE THE CANADIAN AND ECMWF REMAIN QUITE WET
WITH A MORE WESTERN LOW TRACK. WE MAINTAINED SIMILAR POPS TO THE
PREVIOUS PACKAGE BUT INCREASED VALUES A BIT...MAINLY FRIDAY NIGHT
WHEN THE SYSTEM WILL MAKE ITS CLOSEST PASS. THE GREATEST COVERAGE OF
PRECIPITATION WOULD CERTAINLY BE OVER OUR COASTAL WATERS BUT THE
INLAND EXTENT IS QUITE UNCERTAIN AT THIS POINT.

HIGH TEMPS ON SATURDAY WILL REALLY DEPEND ON AMOUNT OF CLOUD COVER
AND WHETHER PRECIPITATION LINGERS AS THE ECMWF CURRENTLY SHOWS. FOR
NOW WE ARE SHOWING HIGHS IN THE MIDDLE 70S...A FEW DEGREES BELOW
CLIMO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EARLY IN THE PERIOD THERE IS STILL CONSIDERABLE UNCERTAINTY
REGARDING THE SURFACE LOW OFF THE FLORIDA COAST. THE DEEPER MODEL
SOLUTIONS KEEP THE LOW LINGERING AROUND WITH RAIN STILL ONGOING
ALONG THE SOUTHEAST COAST. BY MONDAY OR MONDAY NIGHT...THE LOW IS
EXPECTED TO PULL AWAY AND HIGH PRESSURE WILL RETURN TO THE REGION. A
COLD FRONT MAY ATTEMPT TO SAG IN FROM THE NORTH LATE IN THE PERIOD
WITH SOME MODEST INCREASE IN RAIN CHANCES. OVERALL...TEMPERATURES
ARE EXPECTED TO BE RIGHT AROUND CLIMO...ESPECIALLY BY THE MIDDLE OF
NEXT WEEK.

&&

.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
MAINLY VFR. MID-LEVEL CLOUDS WILL INCREASE AFTER 06Z...MAINLY
ACROSS THE SOUTH. LOW PROBABILITIES FOR MVFR CIGS AT BOTH
TERMINALS 09-12Z...BUT CONFIDENCE IS NOT HIGH ENOUGH AT THIS
JUNCTURE TO INCLUDE A MENTION. CAPPED CIGS AT BKN040-050 AT KSAV
AND OPTED NOT TO ESTABLISH CIGS AT KCHS DURING THE ENTIRE TAF
PERIOD.

EXTENDED AVIATION OUTLOOK...LOW CHANCES FOR PERIODIC SUB-VFR
CONDITIONS LATE THURSDAY NIGHT/FRIDAY AS MARINE STRATOCUMULUS
ATTEMPT TO MOVE ONSHORE. BETTER CHANCES FOR FLIGHT RESTRICTIONS
WILL OCCUR FRIDAY NIGHT INTO SATURDAY AS LOW PRESSURE MOVES OUT OF
THE GULF OF MEXICO AND UP THE SOUTHEAST COAST.

&&

.MARINE...
TONIGHT....HIGH PRESSURE WILL STRENGTHEN TO THE NORTH TONIGHT
PRODUCING AN ENHANCED GRADIENT ACROSS THE LOCAL WATERS. THIS MEANS
WINDS WILL INCREASE OVERNIGHT WITH GUSTS NEAR 30 KT AT TIMES...
ESPECIALLY OUTSIDE CHARLESTON HARBOR. SEAS MOSTLY 5 TO 7 FT NEAR
SHORE AND UP TO 9 FT CLOSER TO THE GULF STREAM.

THURSDAY THROUGH SUNDAY...A STRONG RIDGE OF HIGH PRESSURE WILL
REMAIN NORTH OF THE WATERS THROUGH THURSDAY NIGHT BEFORE A GULF
LOW PRESSURE SYSTEM STARTS TAKING SHAPE TO THE SOUTH. THERE ARE
CONSIDERABLE MODEL DIFFERENCES REGARDING THE EVENTUAL TRACK OF THE
LOW...BUT IT WILL AT LEAST INDIRECTLY AFFECT OUR WATERS AS IT
LIFTS NORTHEAST. THE BOTTOM LINE IS THAT A PERSISTENT NORTHEAST
FETCH WITH SOLID SMALL CRAFT ADVISORY WINDS AND/OR SEAS WILL
CONTINUE THROUGH MUCH OF THE UPCOMING WEEKEND. SCA CONDITIONS WILL
LIKELY PERSIST OVER THE OFFSHORE GA WATERS INTO MIDDAY MONDAY DUE
TO LINGERING SEAS.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS CONTINUES INTO
THURSDAY DUE TO PERSISTENT SWELL...LINGERING ASTRONOMICAL INFLUENCES
AND GUSTY ONSHORE WINDS. AN ENHANCED RISK MAY PERSIST INTO THE EARLY
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
CURRENT TIDE TRENDS SUGGEST TIDE LEVELS WILL PEAK JUST UNDER 7.0
FT MLLW IN THE CHARLESTON HARBOR WITH HIGH TIDE THIS EVENING.
HOWEVER...STEADY AND PERSISTENT NORTHEAST WINDS WILL LIKELY CAUSE A
FEW PROBLEMS IN DOWNTOWN CHARLESTON DUE TO ONGOING TIDAL LOADING...
DESPITE TIDES OF 6.8-6.9 FT MLLW. WILL ISSUE A COASTAL FLOOD
STATEMENT FOR CHARLESTON COUNTY TO HIGHLIGHT MINOR IMPACTS IN
DOWNTOWN CHARLESTON...MAINLY IN THE NORMAL FLOOD PRONE AREAS. TIDE
TRENDS WILL CONTINUE TO BE MONITORED OVER THE NEXT FEW HOURS AND
THE NEED FOR A COASTAL FLOOD ADVISORY FOR PARTS OF THE LOWER SOUTH
CAROLINA COAST HAS NOT BEEN COMPLETELY RULED OUT.

TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CLIMATE...
THE HIGH TEMPERATURE IN DOWNTOWN CHARLESTON REACHED 59 DEGREES
LATE THIS AFTERNOON. THEREFORE THE RECORD LOW MAXIMUM OF 58
DEGREES SET IN 1962 WILL STAND.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT SUNDAY FOR AMZ350-352-354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ374.

&&

$$

ST







000
FXUS62 KCHS 162001
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
401 PM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF THE REGION THROUGH THURSDAY NIGHT.
AN AREA OF LOW PRESSURE MAY AFFECT THE REGION FRIDAY AND SATURDAY
AS IT PASSES BY TO THE EAST OVER THE ATLANTIC. HIGH PRESSURE WILL
THEN RETURN TO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH PRESSURE WILL STRENGTHEN TO THE NORTH OVER NEW ENGLAND/MID-
ATLANTIC. THIS WILL MAINTAIN A DECENT PRESSURE GRADIENT OVER THE
LOCAL AREA WHICH MEANS WINDS WILL REMAIN ELEVATED...ESPECIALLY
NEAR THE COAST. SOME LOW-LEVEL MOISTURE AND ISENTROPIC ASCENT LATE
COULD BE ENOUGH TO PRODUCE AT LEAST SOME STRATOCUMULUS AND
POSSIBLY A FEW SHOWERS...MAINLY NEAR THE COAST. OF COURSE CLOUD
COVER WILL PLAY A ROLE IN HOW COLD TEMPS GET. FOR NOW WE LEANED
TOWARD THE COOLER GUIDANCE WHICH MAINTAINS GOOD CONTINUITY FROM
THE PREVIOUS FORECAST. THIS MEANS MID TO UPPER 30S INLAND WITH LOWER
TO MID 40S CLOSER TO THE COAST AND AROUND 50 OR EVEN LOWER 50S AT
THE BEACHES...WARMEST ALONG THE GA COAST. IT APPEARS AS THOUGH
WINDS WILL REMAIN UP ENOUGH TO PREVENT MUCH FROST FORMATION BUT
COULD NOT RULE OUT SOME PATCHY FROST IN THE MORE ISOLATED RURAL
LOCALES IF THEY GET INTO THE MID 30S.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
A LOW-LEVEL RIDGE WILL REMAIN WEDGED DOWN THE EASTERN SEABOARD ON
THURSDAY BUT WILL BE GRADUALLY RETREATING IN RESPONSE TO A DIGGING
UPPER TROUGH FROM THE WEST. MOSTLY SUNNY SKIES WILL PREVAIL IN THE
MORNING...BEFORE CIRRUS STARTS TO INCREASE IN RESPONSE TO A
STRENGTHENING UPPER JET STREAM ACROSS THE SOUTHEAST UNITED STATES.
SCATTERED AFTERNOON CUMULUS IS ALSO POSSIBLE. AS LOW-LEVEL
THICKNESSES WARM...TEMPS SHOULD RESPOND BY RISING INTO THE UPPER 60S
TO AROUND 70.

UPPER VORT ENERGY DEVELOPS THURSDAY NIGHT INTO FRIDAY WITH A SURFACE
LOW FORMING ALONG THE CENTRAL GULF COAST REGION. DEEP LAYERED
MOISTURE WILL INCREASE OVER THE AREA WITH SOME WEAK ISENTROPIC
ASCENT PRODUCING SCATTERED SHOWERS BY DAYBREAK FRIDAY ACROSS
SOUTHERN AREAS. EXTENSIVE CLOUD COVER WILL KEEP HIGHS IN THE
MID/UPPER 60S FRIDAY.

THERE REMAIN MODEL DIFFERENCES REGARDING THE EVENTUAL TRACK OF THE
SURFACE LOW FRIDAY NIGHT AND SATURDAY. THE GFS AND NAM CONTINUE TO
BE THE DRY OUTLIERS WHILE THE CANADIAN AND ECMWF REMAIN QUITE WET
WITH A MORE WESTERN LOW TRACK. WE MAINTAINED SIMILAR POPS TO THE
PREVIOUS PACKAGE BUT INCREASED VALUES A BIT...MAINLY FRIDAY NIGHT
WHEN THE SYSTEM WILL MAKE ITS CLOSEST PASS. THE GREATEST COVERAGE OF
PRECIPITATION WOULD CERTAINLY BE OVER OUR COASTAL WATERS BUT THE
INLAND EXTENT IS QUITE UNCERTAIN AT THIS POINT.

HIGH TEMPS ON SATURDAY WILL REALLY DEPEND ON AMOUNT OF CLOUD COVER
AND WHETHER PRECIPITATION LINGERS AS THE ECMWF CURRENTLY SHOWS. FOR
NOW WE ARE SHOWING HIGHS IN THE MIDDLE 70S...A FEW DEGREES BELOW
CLIMO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EARLY IN THE PERIOD THERE IS STILL CONSIDERABLE UNCERTAINTY
REGARDING THE SURFACE LOW OFF THE FLORIDA COAST. THE DEEPER MODEL
SOLUTIONS KEEP THE LOW LINGERING AROUND WITH RAIN STILL ONGOING
ALONG THE SOUTHEAST COAST. BY MONDAY OR MONDAY NIGHT...THE LOW IS
EXPECTED TO PULL AWAY AND HIGH PRESSURE WILL RETURN TO THE REGION. A
COLD FRONT MAY ATTEMPT TO SAG IN FROM THE NORTH LATE IN THE PERIOD
WITH SOME MODEST INCREASE IN RAIN CHANCES. OVERALL...TEMPERATURES
ARE EXPECTED TO BE RIGHT AROUND CLIMO...ESPECIALLY BY THE MIDDLE OF
NEXT WEEK.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS AT BOTH KSAV AND KCHS THROUGH 06Z THURSDAY...THEN
THERE WILL BE A LOW RISK FOR MVFR CIGS AT THE TERMS AS LOW-LEVEL
MOISTURE INCREASES FROM OFF THE ATLANTIC. OTHERWISE...THE MAIN
ISSUE WILL BE ELEVATED/GUSTY N TO NE WINDS...MAINLY LATE TONIGHT
INTO THURSDAY.

EXTENDED AVIATION OUTLOOK...  LOW CHANCES FOR PERIODIC SUB-VFR
CONDITIONS LATE THURSDAY NIGHT/FRIDAY AS MARINE STRATOCUMULUS
ATTEMPT TO MOVE ONSHORE. BETTER CHANCES FOR FLIGHT RESTRICTIONS WILL
OCCUR FRIDAY NIGHT INTO SATURDAY AS LOW PRESSURE MOVES OUT OF THE
GULF OF MEXICO AND UP THE SOUTHEAST COAST.

&&

.MARINE...
TONIGHT....HIGH PRESSURE WILL STRENGTHEN TO THE NORTH TONIGHT
PRODUCING AN ENHANCED GRADIENT ACROSS THE LOCAL WATERS. THIS MEANS
WINDS WILL INCREASE OVERNIGHT WITH GUSTS NEAR 30 KT AT
TIMES...ESPECIALLY OUTSIDE CHARLESTON HARBOR. SEAS MOSTLY 5 TO 7
FT NEAR SHORE AND UP TO 9 FT CLOSER TO THE GULF STREAM.

THURSDAY THROUGH SUNDAY...A STRONG RIDGE OF HIGH PRESSURE WILL
REMAIN NORTH OF THE WATERS THROUGH THURSDAY NIGHT BEFORE A GULF
LOW PRESSURE SYSTEM STARTS TAKING SHAPE TO THE SOUTH. THERE ARE
CONSIDERABLE MODEL DIFFERENCES REGARDING THE EVENTUAL TRACK OF THE
LOW...BUT IT WILL AT LEAST INDIRECTLY AFFECT OUR WATERS AS IT
LIFTS NORTHEAST. THE BOTTOM LINE IS THAT A PERSISTENT NORTHEAST
FETCH WITH SOLID SMALL CRAFT ADVISORY WINDS AND/OR SEAS WILL
CONTINUE THROUGH MUCH OF THE UPCOMING WEEKEND. SCA CONDITIONS WILL
LIKELY PERSIST OVER THE OFFSHORE GA WATERS INTO MIDDAY MONDAY DUE
TO LINGERING SEAS.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS CONTINUES INTO
THURSDAY DUE TO PERSISTENT SWELL...LINGERING ASTRONOMICAL INFLUENCES
AND GUSTY ONSHORE WINDS. AN ENHANCED RISK MAY PERSIST INTO THE EARLY
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
TIDES ARE RUNNING ABOVE WHAT THEY SHOULD BE GIVEN THE STRONG
NORTHEAST WINDS AND THIS COULD PUSH LEVELS HIGH ENOUGH TO PRODUCE
SOME SHALLOW INUNDATION OF SALTWATER NEAR THE COAST DURING THIS
EVENING/S HIGH TIDE...ESPECIALLY AROUND CHARLESTON. THUS...A
COASTAL FLOOD ADVISORY MAY BE NEEDED.

TIDES WILL CONTINUE TO RUN HIGH THROUGH THE WEEKEND AND COASTAL
FLOOD ADVISORIES COULD BE NEEDED DURING THE NIGHTTIME HIGH TIDE
CYCLES.

&&

.CLIMATE...
DOWNTOWN CHARLESTON MAY TIE OR BREAK THE RECORD LOW MAX
TEMPERATURE FOR TODAY. THE CURRENT RECORD IS 58 DEGREES SET IN 1962.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT SUNDAY FOR AMZ350-352-354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR AMZ374.

&&

$$

SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...JRL
LONG TERM...BSH
AVIATION...JRL/RJB
MARINE...JRL/RJB
TIDES/COASTAL FLOODING...
CLIMATE...








000
FXUS62 KCHS 161759
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
159 PM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF THE REGION THROUGH THURSDAY NIGHT.
AN AREA OF LOW PRESSURE MAY AFFECT THE REGION FRIDAY AND SATURDAY
AS IT PASSES BY TO THE EAST OVER THE ATLANTIC. HIGH PRESSURE WILL
THEN RETURN TO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...NO MAJOR CHANGES TO THE PREVIOUS FORECAST BUT DID TWEAK
HIGHS DOWN A BIT AND CANCELLED THE LAKE WIND ADVISORY A BIT EARLY
AS GUSTS SHOULD REMAIN BELOW 25 KT THE REST OF THE AFTERNOON. TEMPERATURES
ONLY IN THE MID TO UPPER 50S AS OF 1 PM...BUT EVEN COOLER AROUND
50 DEGREES ALONG THE COAST. IN FACT...DOWNTOWN CHARLESTON MAY SET
A RECORD LOW MAX TEMP THIS AFTERNOON. THE PREVIOUS RECORD IS 58
DEGREES SET IN 1962. OTHERWISE...WINDS WILL REMAIN BREEZY AT
TIMES...ESPECIALLY AT THE COAST.

TONIGHT...WILL HAVE TO WATCH FOR ANY SIGNIFICANT DECOUPLING
POTENTIAL WELL INLAND TO THE NORTH OF I-16 AS LOW TEMPS DIP TOWARD
THE MID 30S AT SOME OF THE NORMALLY COLDER RURAL LOCATIONS FROM
ALLENDALE TO SUMMERVILLE. WE CONTINUE TO SHOW JUST ENOUGH
GRADIENT/WIND TO OMIT ANY MENTIONS FOR PATCHY FROST ESPECIALLY
SINCE THE GRADIENT TIGHTENS BEFORE DAWN ON THURSDAY AND THERE IS A
WEAK MOIST FLUX COMING IN FROM THE ATLC IN THE BOUNDARY LAYER.
MORE OF AN ONSHORE COMPONENT ACROSS SE GEORGIA SHOULD KEEP
READINGS A BIT WARMER ALONG AND S OF I-16 OVERNIGHT. SOME INCREASE
IN STRATOCU COASTAL AREAS IS LIKELY LATE WITH WEAK ISENTROPIC LIFT
DEVELOPING.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY AND THURSDAY NIGHT...ALOFT THE REGION WILL BE IN THE
SOUTHWEST FLOW ASSOCIATED WITH THE BROAD LONGWAVE THAT ENCOMPASSES
MUCH OF THE EASTERN HALF OF THE CONUS. THE STRONG DAMMING 1043 MB
HIGH OVER THE NORTHEAST WILL PERSIST THOUGH IT WILL BEGIN TO RETREAT
EVEN FURTHER NORTHEASTWARD WITH TIME. THIS WILL LEAVE THE AREA IN
THE STRONG RIDGING EAST OF THE APPALACHIANS WITH COOL NORTHEAST FLOW
PREVAILING. MODEL TIME HEIGHTS AND SOUNDINGS SHOW ALL OF THE
MOISTURE IN THE COLUMN CONFINED TO THE LOWEST 5 KFT WITH
CONSIDERABLE DRY AIR IN THE MID AND UPPER LEVELS. THE MODELS
CONTINUE TO SHOW POTENTIAL FOR SHOWER DEVELOPMENT OVER THE COASTAL
WATERS AND PERHAPS ALONG THE GEORGIA COAST ON THURSDAY. BY THURSDAY
NIGHT RAIN CHANCES BEGIN TO EXPAND NORTHWARD AND FURTHER INLAND AS
AN AREA OF LOW PRESSURE BEGINS TO ORGANIZE OVER THE NORTHEAST GULF.
THURSDAY POPS HAVE BEEN LIMITED TO SLIGHT CHANCES AND THURSDAY NIGHT
HAVE BEEN CAPPED AT CHANCE FOR NOW. HIGHS WILL BE ON THE COOL SIDE
WITH UPPER 60S IN MOST LOCATIONS. LOWS WILL BE IN THE UPPER 40S
INLAND AND NORTH...WITH MID TO UPPER 50S FURTHER SOUTH.

FRIDAY THROUGH SATURDAY...THE FORECAST BECOMES MORE INTERESTING AND
INHERENTLY LESS CERTAIN FOR THE LATE WEEK AND EARLY WEEKEND. IN
GENERAL...THE MODELS SHOW A SOUTHERN STREAM DISTURBANCE IN THE
MID/UPPER LEVELS SWINGING THROUGH THE NORTHERN GULF AND KICKING OFF
SURFACE LOW DEVELOPMENT. AS THIS LOW DEVELOPS...MOISTURE WILL SPREAD
NORTHWARD ALONG AND JUST OFF THE SOUTHEAST COAST WITH THE POTENTIAL
FOR INCREASING RAINFALL CHANCES. SPECIFIC MODEL SOLUTIONS TRULY RUN
THE SPECTRUM. FOR INSTANCE THE 00Z/16 ECMWF ALLOWS THE UPPER
DISTURBANCE TO DEEPEN SIGNIFICANTLY AND FORM A CLOSED LOW OVER THE
FLORIDA PANHANDLE FRIDAY NIGHT. THIS RESULTS IN A SLOWER DEVELOPING
LOW WITH TREMENDOUS MOISTURE AND DEEP FORCING TO SPREAD INTO
SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA. SUCH A SOLUTION
WOULD RESULT IN THE POTENTIAL FOR WIDESPREAD HEAVY RAINFALL THROUGH
THE DAY ON SATURDAY. ON THE OTHER HAND...THE GFS IS MUCH WEAKER WITH
THE UPPER DISTURBANCE AND RESULTING LOW AND KEEPS THE PRECIP AXIS
LIGHTER AND OVER NORTH FLORIDA AND THE ATLANTIC. GIVEN THE
UNCERTAINTY AND EXISTING MODEL DISAGREEMENT...I HAVE NOT MADE ANY
SIGNIFICANT CHANGES TO THE FORECAST. POPS FEATURE A TIGHT GRADIENT
WITH HIGHEST VALUES OVER THE WATERS. I HAVE INTRODUCED SOME
CATEGORICAL POPS OVER THE WATERS AND TO THE SOUTH...BUT MAINTAINED
THE SLIGHT CHANCE TO CHANCE POPS FOR INLAND AREAS. OBVIOUSLY ALL OF
THE FORECAST PARAMETERS WILL ULTIMATELY BE DETERMINED BY THE
DEVELOPMENT AND TRACK OF THE LOW BUT FOR NOW TEMPS FEATURE ANOTHER
COOL DAY ON FRIDAY FOLLOWED BY NEAR NORMAL VALUES FOR SATURDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
EARLY IN THE PERIOD THERE IS STILL CONSIDERABLE UNCERTAINTY
REGARDING THE SURFACE LOW OFF THE FLORIDA COAST. THE DEEPER MODEL
SOLUTIONS KEEP THE LOW LINGERING AROUND WITH RAIN STILL ONGOING
ALONG THE SOUTHEAST COAST. BY MONDAY OR MONDAY NIGHT...THE LOW IS
EXPECTED TO PULL AWAY AND HIGH PRESSURE WILL RETURN TO THE REGION. A
COLD FRONT MAY ATTEMPT TO SAG IN FROM THE NORTH LATE IN THE PERIOD
WITH SOME MODEST INCREASE IN RAIN CHANCES. OVERALL...TEMPERATURES
ARE EXPECTED TO BE RIGHT AROUND CLIMO...ESPECIALLY BY THE MIDDLE OF
NEXT WEEK.

&&

.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS AT BOTH KSAV AND KCHS THROUGH 06Z THURSDAY...THEN
THERE WILL BE A LOW RISK FOR MVFR CIGS AT THE TERMS AS LOW-LEVEL
MOISTURE INCREASES FROM OFF THE ATLANTIC. OTHERWISE...THE MAIN
ISSUE WILL BE ELEVATED/GUSTY N TO NE WINDS...MAINLY LATE TONIGHT
INTO THURSDAY.

EXTENDED AVIATION OUTLOOK... LOW CHANCES FOR PERIODIC SUB-VFR
CONDITIONS LATE THURSDAY NIGHT/FRIDAY AS MARINE STRATOCUMULUS
ATTEMPT TO MOVE ONSHORE. BETTER CHANCES FOR FLIGHT RESTRICTIONS
WILL OCCUR BY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF
MEXICO AND OFF THE EAST COAST OF FLORIDA.

&&

.MARINE...
THROUGH TONIGHT....HIGH PRES WEDGING INTO GEORGIA AND THE
CAROLINAS FROM THE NORTH WILL MAINTAIN TIGHT THERMAL AND MOISTURE
GRADIENTS OVER THE ATLC WATERS FROM CHARLESTON TO SOUTH OF
SAVANNAH. WINDS WILL BE NE WITH THE MORNING SURGE EBBING AND THEN
RAMPING UP AGAIN AFTER MIDNIGHT TONIGHT. SMALL CRAFT ADVISORIES
WILL CONTINUE ALL WATERS AND THE CHARLESTON HARBOR THROUGH TONIGHT
WITH SEAS BUILDING TO 5 TO 7 FT NEAR SHORE AND REMAINING 7-9 FT
CLOSER TO THE GULF STREAM.

THURSDAY THROUGH SUNDAY...A STRONG RIDGE OF HIGH PRESSURE WILL
REMAIN ACROSS INLAND AREAS WITH A TIGHT NORTHEAST GRADIENT IN PLACE
ACROSS THE LOCAL WATERS. THE GRADIENT WILL HELP SUPPORT SOLID SMALL
CRAFT ADVISORY WINDS/SEAS THROUGH THE REST OF THE WEEK AND INTO THE
UPCOMING WEEKEND. FORECAST CONFIDENCE THEN LESSENS EARLY IN THE
WEEKEND AS AN AREA OF LOW PRESSURE IS EXPECTED TO CROSS THE FLORIDA
PENINSULA AND EMERGE OVER THE ATLANTIC. THE EVENTUAL TRACK OF THIS
LOW AND THE RESULTING GRADIENT ON ITS NORTH SIDE WILL DETERMINE
MARINE CONDITIONS THROUGH THE END OF THE FORECAST PERIOD. WINDS AND
SEAS COULD INCREASE IF THE LOW MOVES CLOSER TO THE AREA DURING THIS
TIME...BUT THERE IS NOT ENOUGH CONFIDENCE IN THE FORECAST TO SAY AT
THIS POINT.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS ALL BEACHES TODAY AS
THE LOW-LEVEL FLOW TIPS NORTHEAST AND COMBINE WITH ELEVATED SEAS
AND LINGERING ASTRONOMICAL INFLUENCES. STRONG NORTHEAST WINDS AND
LINGERING ASTRONOMICAL INFLUENCES WILL RESULT IN AN ENHANCED RISK
OF RIP CURRENTS THROUGH AT LEAST FRIDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.
     SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT SUNDAY FOR AMZ374.

&&

$$

SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...BSH
LONG TERM...BSH
AVIATION...RJB
MARINE...BSH








000
FXUS62 KCHS 161506
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1106 AM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF THE REGION THROUGH THURSDAY NIGHT.
AN AREA OF LOW PRESSURE MAY AFFECT THE REGION FRIDAY AND SATURDAY
AS IT PASSES BY TO THE EAST OVER THE ATLANTIC. HIGH PRESSURE WILL
THEN RETURN TO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...NO MAJOR CHANGES TO THE PREVIOUS FORECAST. HIGH PRESSURE
WILL REMAIN TO THE NORTH WITH AN UNSEASONABLY COOL AIR MASS
PERSISTING OVER THE REGION. LOW-LEVEL MOISTURE RIDING SOUTHWEST
AROUND THE EASTERN EDGE OF THE HIGH WILL FLIRT WITH THE
COAST...LIKELY PUSHING A BIT MORE ONSHORE ACROSS SOUTHEAST GEORGIA
WHERE THE TRAJECTORIES ARE MORE EASTERLY. THE TIGHT PRESSURE
GRADIENT WILL SUPPORT BREEZY CONDITIONS THROUGH THE
DAY...STRONGEST AT THE COAST...WHILE THE DIMINISHING LOW-LEVEL JET
WILL MAKE FOR A LESSENING OF THE WIND GUSTS. HIGH TEMPS SHOULD
ONLY REACH THE LOWER 60S ACROSS SOUTHERN SC/INTERIOR SOUTHEAST GA
WITH MID 60S ELSEWHERE. COASTAL LOCALES WILL REMAIN
CHILLIER...LIKELY ONLY TOPPING OUT AROUND 60.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND DECENT MIXING ACROSS LAKE
MOULTRIE WILL SUPPORT A LAKE WIND ADVISORY INTO THE FIRST PART OF
THIS AFTERNOON.

TONIGHT...WILL HAVE TO WATCH FOR ANY SIGNIFICANT DECOUPLING POTENTIAL
WELL INLAND TO THE NORTH OF I-16 AS LOW TEMPS DIP TOWARD THE MID
30S AT SOME OF THE NORMALLY COLDER RURAL LOCATIONS FROM ALLENDALE
TO SUMMERVILLE. WE CONTINUE TO SHOW JUST ENOUGH GRADIENT/WIND TO
OMIT ANY MENTIONS FOR PATCHY FROST ESPECIALLY SINCE THE GRADIENT
TIGHTENS BEFORE DAWN ON THURSDAY AND THERE IS A WEAK MOIST FLUX
COMING IN FROM THE ATLC IN THE BOUNDARY LAYER. MORE OF AN ONSHORE
COMPONENT ACROSS SE GEORGIA SHOULD KEEP READINGS A BIT WARMER
ALONG AND S OF I-16 OVERNIGHT. SOME INCREASE IN STRATOCU COASTAL
AREAS IS LIKELY LATE WITH WEAK ISENTROPIC LIFT DEVELOPING.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY AND THURSDAY NIGHT...ALOFT THE REGION WILL BE IN THE
SOUTHWEST FLOW ASSOCIATED WITH THE BROAD LONGWAVE THAT ENCOMPASSES
MUCH OF THE EASTERN HALF OF THE CONUS. THE STRONG DAMMING 1043 MB
HIGH OVER THE NORTHEAST WILL PERSIST THOUGH IT WILL BEGIN TO RETREAT
EVEN FURTHER NORTHEASTWARD WITH TIME. THIS WILL LEAVE THE AREA IN
THE STRONG RIDGING EAST OF THE APPALACHIANS WITH COOL NORTHEAST FLOW
PREVAILING. MODEL TIME HEIGHTS AND SOUNDINGS SHOW ALL OF THE
MOISTURE IN THE COLUMN CONFINED TO THE LOWEST 5 KFT WITH
CONSIDERABLE DRY AIR IN THE MID AND UPPER LEVELS. THE MODELS
CONTINUE TO SHOW POTENTIAL FOR SHOWER DEVELOPMENT OVER THE COASTAL
WATERS AND PERHAPS ALONG THE GEORGIA COAST ON THURSDAY. BY THURSDAY
NIGHT RAIN CHANCES BEGIN TO EXPAND NORTHWARD AND FURTHER INLAND AS
AN AREA OF LOW PRESSURE BEGINS TO ORGANIZE OVER THE NORTHEAST GULF.
THURSDAY POPS HAVE BEEN LIMITED TO SLIGHT CHANCES AND THURSDAY NIGHT
HAVE BEEN CAPPED AT CHANCE FOR NOW. HIGHS WILL BE ON THE COOL SIDE
WITH UPPER 60S IN MOST LOCATIONS. LOWS WILL BE IN THE UPPER 40S
INLAND AND NORTH...WITH MID TO UPPER 50S FURTHER SOUTH.

FRIDAY THROUGH SATURDAY...THE FORECAST BECOMES MORE INTERESTING AND
INHERENTLY LESS CERTAIN FOR THE LATE WEEK AND EARLY WEEKEND. IN
GENERAL...THE MODELS SHOW A SOUTHERN STREAM DISTURBANCE IN THE
MID/UPPER LEVELS SWINGING THROUGH THE NORTHERN GULF AND KICKING OFF
SURFACE LOW DEVELOPMENT. AS THIS LOW DEVELOPS...MOISTURE WILL SPREAD
NORTHWARD ALONG AND JUST OFF THE SOUTHEAST COAST WITH THE POTENTIAL
FOR INCREASING RAINFALL CHANCES. SPECIFIC MODEL SOLUTIONS TRULY RUN
THE SPECTRUM. FOR INSTANCE THE 00Z/16 ECMWF ALLOWS THE UPPER
DISTURBANCE TO DEEPEN SIGNIFICANTLY AND FORM A CLOSED LOW OVER THE
FLORIDA PANHANDLE FRIDAY NIGHT. THIS RESULTS IN A SLOWER DEVELOPING
LOW WITH TREMENDOUS MOISTURE AND DEEP FORCING TO SPREAD INTO
SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA. SUCH A SOLUTION
WOULD RESULT IN THE POTENTIAL FOR WIDESPREAD HEAVY RAINFALL THROUGH
THE DAY ON SATURDAY. ON THE OTHER HAND...THE GFS IS MUCH WEAKER WITH
THE UPPER DISTURBANCE AND RESULTING LOW AND KEEPS THE PRECIP AXIS
LIGHTER AND OVER NORTH FLORIDA AND THE ATLANTIC. GIVEN THE
UNCERTAINTY AND EXISTING MODEL DISAGREEMENT...I HAVE NOT MADE ANY
SIGNIFICANT CHANGES TO THE FORECAST. POPS FEATURE A TIGHT GRADIENT
WITH HIGHEST VALUES OVER THE WATERS. I HAVE INTRODUCED SOME
CATEGORICAL POPS OVER THE WATERS AND TO THE SOUTH...BUT MAINTAINED
THE SLIGHT CHANCE TO CHANCE POPS FOR INLAND AREAS. OBVIOUSLY ALL OF
THE FORECAST PARAMETERS WILL ULTIMATELY BE DETERMINED BY THE
DEVELOPMENT AND TRACK OF THE LOW BUT FOR NOW TEMPS FEATURE ANOTHER
COOL DAY ON FRIDAY FOLLOWED BY NEAR NORMAL VALUES FOR SATURDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
EARLY IN THE PERIOD THERE IS STILL CONSIDERABLE UNCERTAINTY
REGARDING THE SURFACE LOW OFF THE FLORIDA COAST. THE DEEPER MODEL
SOLUTIONS KEEP THE LOW LINGERING AROUND WITH RAIN STILL ONGOING
ALONG THE SOUTHEAST COAST. BY MONDAY OR MONDAY NIGHT...THE LOW IS
EXPECTED TO PULL AWAY AND HIGH PRESSURE WILL RETURN TO THE REGION. A
COLD FRONT MAY ATTEMPT TO SAG IN FROM THE NORTH LATE IN THE PERIOD
WITH SOME MODEST INCREASE IN RAIN CHANCES. OVERALL...TEMPERATURES
ARE EXPECTED TO BE RIGHT AROUND CLIMO...ESPECIALLY BY THE MIDDLE OF
NEXT WEEK.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS AT BOTH KSAV AND KCHS THROUGH 06Z THURSDAY. THE
MAIN ISSUE TODAY WITH BE N TO NE SURFACE WINDS PRODUCING PREVAILING
GUSTS IN THE 20-25 KT RANGE THROUGH MID-LATE AFTERNOON.

EXTENDED AVIATION OUTLOOK... LOW CHANCES FOR PERIODIC SUB-VFR
CONDITIONS BEGINNING FRIDAY AS MARINE STRATOCUMULUS ATTEMPT TO
MOVE ONSHORE. BETTER CHANCES FOR FLIGHT RESTRICTIONS WILL OCCUR BY
SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND OFF
THE EAST COAST OF FLORIDA.

&&

.MARINE...
THROUGH TONIGHT....HIGH PRES WEDGING INTO GEORGIA AND THE
CAROLINAS FROM THE NORTH WILL MAINTAIN TIGHT THERMAL AND MOISTURE
GRADIENTS OVER THE ATLC WATERS FROM CHARLESTON TO SOUTH OF
SAVANNAH. WINDS WILL BE NE WITH THE MORNING SURGE EBBING AND THEN
RAMPING UP AGAIN AFTER MIDNIGHT TONIGHT. SMALL CRAFT ADVISORIES
WILL CONTINUE ALL WATERS AND THE CHARLESTON HARBOR THROUGH TONIGHT
WITH SEAS BUILDING TO 5 TO 7 FT NEAR SHORE AND REMAINING 7-9 FT
CLOSER TO THE GULF STREAM.

THURSDAY THROUGH SUNDAY...A STRONG RIDGE OF HIGH PRESSURE WILL
REMAIN ACROSS INLAND AREAS WITH A TIGHT NORTHEAST GRADIENT IN PLACE
ACROSS THE LOCAL WATERS. THE GRADIENT WILL HELP SUPPORT SOLID SMALL
CRAFT ADVISORY WINDS/SEAS THROUGH THE REST OF THE WEEK AND INTO THE
UPCOMING WEEKEND. FORECAST CONFIDENCE THEN LESSENS EARLY IN THE
WEEKEND AS AN AREA OF LOW PRESSURE IS EXPECTED TO CROSS THE FLORIDA
PENINSULA AND EMERGE OVER THE ATLANTIC. THE EVENTUAL TRACK OF THIS
LOW AND THE RESULTING GRADIENT ON ITS NORTH SIDE WILL DETERMINE
MARINE CONDITIONS THROUGH THE END OF THE FORECAST PERIOD. WINDS AND
SEAS COULD INCREASE IF THE LOW MOVES CLOSER TO THE AREA DURING THIS
TIME...BUT THERE IS NOT ENOUGH CONFIDENCE IN THE FORECAST TO SAY AT
THIS POINT.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS ALL BEACHES TODAY AS
THE LOW-LEVEL FLOW TIPS NORTHEAST AND COMBINE WITH ELEVATED SEAS
AND LINGERING ASTRONOMICAL INFLUENCES. STRONG NORTHEAST WINDS AND
LINGERING ASTRONOMICAL INFLUENCES WILL RESULT IN AN ENHANCED RISK
OF RIP CURRENTS THROUGH AT LEAST FRIDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT SUNDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...BSH
LONG TERM...BSH
AVIATION...
MARINE...BSH








000
FXUS62 KCHS 160815
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
415 AM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD NORTH OF THE REGION THROUGH THURSDAY NIGHT.
AN AREA OF LOW PRESSURE MAY AFFECT THE REGION FRIDAY AND SATURDAY
AS IT PASSES BY TO THE EAST OVER THE ATLANTIC. HIGH PRESSURE WILL
THEN RETURN TO THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...THE LAST OF THE STRATOCUMULUS FIELDS EXITING FAR SOUTHERN
SOUTH CAROLINA AROUND BEAUFORT AND THE IMMEDIATE GEORGIA COAST. CLEAR
SKIES WITH A FEW THIN CIRRUS OTHERWISE AS SURFACE HIGH PRES BUILDS
IN FROM THE NW IN THE WAKE OF THE STRONG COLD FRONT WHICH SWEPT OFFSHORE
LAST EVENING. STEADY COLD AIR ADVECTION ONGOING AS THE 0C DEGREE
925 MB ISOTHERM FORECAST TO REACH CHARLESTON BY MID MORNING. LOWS
FROM THE UPPER 30S INLAND TO THE MID-UPPER 40S AT THE COAST. NORTH
WINDS WILL PRODUCE WIND CHILLS IN THE LOWER TO MID 30S MANY AREAS.

SURFACE HIGH PRES BUILDING INTO THE NEW ENGLAND AND MID ATLC REGIONS
WILL WEDGE SOUTH INTO GEORGIA AND SOUTH CAROLINA TODAY AND TONIGHT
AS THE BAROCLINIC REGION EVENTUALLY STALLS ACROSS THE SOUTHERN HALF
OF FLORIDA AND THE SW ATLC. SUNSHINE WITH BREEZY WEATHER ON TAP
TODAY. LOW LEVEL GEOSTROPHIC FLOW TENDS TO DECREASE WITH TIME
AFTER MIDDAY...THUS WIND GUSTS SHOULD BECOME LESS FREQUENT TOWARD
THE MID TO LATE AFTERNOON EXCEPT BEACHES AND BARRIER ISLANDS. COOL
LOW LEVEL THICKNESS VALUES AND NORTHERLY FLOW BECOMING NORTHEAST
SUGGEST HIGH TEMPS ONLY IN THE 60-65 DEGREE RANGE ALL INLAND AREAS.

TONIGHT...WILL HAVE TO WATCH FOR ANY SIGNIFICANT DECOUPLING POTENTIAL
WELL INLAND TO THE NORTH OF I-16 AS LOW TEMPS DIP TOWARD THE MID
30S AT SOME OF THE NORMALLY COLDER RURAL LOCATIONS FROM ALLENDALE
TO SUMMERVILLE. WE CONTINUE TO SHOW JUST ENOUGH GRADIENT/WIND TO
OMIT ANY MENTIONS FOR PATCHY FROST ESPECIALLY SINCE THE GRADIENT
TIGHTENS BEFORE DAWN ON THURSDAY AND THERE IS A WEAK MOIST FLUX
COMING IN FROM THE ATLC IN THE BOUNDARY LAYER. MORE OF AN ONSHORE
COMPONENT ACROSS SE GEORGIA SHOULD KEEP READINGS A BIT WARMER
ALONG AND S OF I-16 OVERNIGHT. SOME INCREASE IN STRATOCU COASTAL
AREAS IS LIKELY LATE WITH WEAK ISENTROPIC LIFT DEVELOPING.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND DECENT MIXING ACROSS LAKE
MOULTRIE SUPPORTING A LAKE WIND ADVISORY INTO THE FIRST PART OF
THIS AFTERNOON. THE ADVISORY CONTINUES THROUGH THE MORNING HOURS.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY AND THURSDAY NIGHT...ALOFT THE REGION WILL BE IN THE
SOUTHWEST FLOW ASSOCIATED WITH THE BROAD LONGWAVE THAT ENCOMPASSES
MUCH OF THE EASTERN HALF OF THE CONUS. THE STRONG DAMMING 1043 MB
HIGH OVER THE NORTHEAST WILL PERSIST THOUGH IT WILL BEGIN TO RETREAT
EVEN FURTHER NORTHEASTWARD WITH TIME. THIS WILL LEAVE THE AREA IN
THE STRONG RIDGING EAST OF THE APPALACHIANS WITH COOL NORTHEAST FLOW
PREVAILING. MODEL TIME HEIGHTS AND SOUNDINGS SHOW ALL OF THE
MOISTURE IN THE COLUMN CONFINED TO THE LOWEST 5 KFT WITH
CONSIDERABLE DRY AIR IN THE MID AND UPPER LEVELS. THE MODELS
CONTINUE TO SHOW POTENTIAL FOR SHOWER DEVELOPMENT OVER THE COASTAL
WATERS AND PERHAPS ALONG THE GEORGIA COAST ON THURSDAY. BY THURSDAY
NIGHT RAIN CHANCES BEGIN TO EXPAND NORTHWARD AND FURTHER INLAND AS
AN AREA OF LOW PRESSURE BEGINS TO ORGANIZE OVER THE NORTHEAST GULF.
THURSDAY POPS HAVE BEEN LIMITED TO SLIGHT CHANCES AND THURSDAY NIGHT
HAVE BEEN CAPPED AT CHANCE FOR NOW. HIGHS WILL BE ON THE COOL SIDE
WITH UPPER 60S IN MOST LOCATIONS. LOWS WILL BE IN THE UPPER 40S
INLAND AND NORTH...WITH MID TO UPPER 50S FURTHER SOUTH.

FRIDAY THROUGH SATURDAY...THE FORECAST BECOMES MORE INTERESTING AND
INHERENTLY LESS CERTAIN FOR THE LATE WEEK AND EARLY WEEKEND. IN
GENERAL...THE MODELS SHOW A SOUTHERN STREAM DISTURBANCE IN THE
MID/UPPER LEVELS SWINGING THROUGH THE NORTHERN GULF AND KICKING OFF
SURFACE LOW DEVELOPMENT. AS THIS LOW DEVELOPS...MOISTURE WILL SPREAD
NORTHWARD ALONG AND JUST OFF THE SOUTHEAST COAST WITH THE POTENTIAL
FOR INCREASING RAINFALL CHANCES. SPECIFIC MODEL SOLUTIONS TRULY RUN
THE SPECTRUM. FOR INSTANCE THE 00Z/16 ECMWF ALLOWS THE UPPER
DISTURBANCE TO DEEPEN SIGNIFICANTLY AND FORM A CLOSED LOW OVER THE
FLORIDA PANHANDLE FRIDAY NIGHT. THIS RESULTS IN A SLOWER DEVELOPING
LOW WITH TREMENDOUS MOISTURE AND DEEP FORCING TO SPREAD INTO
SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA. SUCH A SOLUTION
WOULD RESULT IN THE POTENTIAL FOR WIDESPREAD HEAVY RAINFALL THROUGH
THE DAY ON SATURDAY. ON THE OTHER HAND...THE GFS IS MUCH WEAKER WITH
THE UPPER DISTURBANCE AND RESULTING LOW AND KEEPS THE PRECIP AXIS
LIGHTER AND OVER NORTH FLORIDA AND THE ATLANTIC. GIVEN THE
UNCERTAINTY AND EXISTING MODEL DISAGREEMENT...I HAVE NOT MADE ANY
SIGNIFICANT CHANGES TO THE FORECAST. POPS FEATURE A TIGHT GRADIENT
WITH HIGHEST VALUES OVER THE WATERS. I HAVE INTRODUCED SOME
CATEGORICAL POPS OVER THE WATERS AND TO THE SOUTH...BUT MAINTAINED
THE SLIGHT CHANCE TO CHANCE POPS FOR INLAND AREAS. OBVIOUSLY ALL OF
THE FORECAST PARAMETERS WILL ULTIMATELY BE DETERMINED BY THE
DEVELOPMENT AND TRACK OF THE LOW BUT FOR NOW TEMPS FEATURE ANOTHER
COOL DAY ON FRIDAY FOLLOWED BY NEAR NORMAL VALUES FOR SATURDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
EARLY IN THE PERIOD THERE IS STILL CONSIDERABLE UNCERTAINTY
REGARDING THE SURFACE LOW OFF THE FLORIDA COAST. THE DEEPER MODEL
SOLUTIONS KEEP THE LOW LINGERING AROUND WITH RAIN STILL ONGOING
ALONG THE SOUTHEAST COAST. BY MONDAY OR MONDAY NIGHT...THE LOW IS
EXPECTED TO PULL AWAY AND HIGH PRESSURE WILL RETURN TO THE REGION. A
COLD FRONT MAY ATTEMPT TO SAG IN FROM THE NORTH LATE IN THE PERIOD
WITH SOME MODEST INCREASE IN RAIN CHANCES. OVERALL...TEMPERATURES
ARE EXPECTED TO BE RIGHT AROUND CLIMO...ESPECIALLY BY THE MIDDLE OF
NEXT WEEK.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS AT BOTH KSAV AND KCHS THROUGH 06Z THURSDAY. THE
MAIN ISSUE TODAY WITH BE N TO NE SURFACE WINDS PRODUCING PREVAILING
GUSTS IN THE 20-25 KT RANGE FROM MID MORNING THROUGH MID-LATE
AFTERNOON.

LOW CHANCES FOR PERIODIC SUB-VFR CONDITIONS BEGINNING FRIDAY AS
MARINE STRATOCUMULUS ATTEMPT TO MOVE ONSHORE. BETTER CHANCES FOR
FLIGHT RESTRICTIONS WILL OCCUR BY SATURDAY AS LOW PRESSURE MOVES OUT
OF THE GULF OF MEXICO AND OFF THE EAST COAST OF FLORIDA.

&&

.MARINE...
WE HAVE CONTINUED THE GALE WARNING FOR THE OUTER WATERS EARLY THIS
MORNING AS LATEST SURFACE ANALYSIS SHOWS A IMPRESSIVE GRADIENT
SEAWARD FROM GRAYS REEF AND THE LOW LEVEL LAPSE RATES WERE ONLY
STEEPENING WITH TIME.

OTHERWISE THROUGH TONIGHT....HIGH PRES WEDGING INTO GEORGIA AND
THE CAROLINAS FROM THE NORTH WILL MAINTAIN TIGHT THERMAL AND
MOISTURE GRADIENTS OVER THE ATLC WATERS FROM CHARLESTON TO SOUTH
OF SAVANNAH. WINDS WILL VEER NE BY LATER THIS MORNING WITH THE
MORNING SURGE EBBING AND THEN RAMPING UP AGAIN AFTER MIDNIGHT
TONIGHT. SMALL CRAFT ADVISORIES WILL CONTINUE ALL WATERS AND
THE CHARLESTON HARBOR THROUGH TONIGHT WITH SEAS BUILDING TO 5
TO 7 FT NEAR SHORE AND REMAINING 7-9 FT CLOSER TO THE GULF
STREAM.

THURSDAY THROUGH SUNDAY...A STRONG RIDGE OF HIGH PRESSURE WILL
REMAIN ACROSS INLAND AREAS WITH A TIGHT NORTHEAST GRADIENT IN PLACE
ACROSS THE LOCAL WATERS. THE GRADIENT WILL HELP SUPPORT SOLID SMALL
CRAFT ADVISORY WINDS/SEAS THROUGH THE REST OF THE WEEK AND INTO THE
UPCOMING WEEKEND. FORECAST CONFIDENCE THEN LESSENS EARLY IN THE
WEEKEND AS AN AREA OF LOW PRESSURE IS EXPECTED TO CROSS THE FLORIDA
PENINSULA AND EMERGE OVER THE ATLANTIC. THE EVENTUAL TRACK OF THIS
LOW AND THE RESULTING GRADIENT ON ITS NORTH SIDE WILL DETERMINE
MARINE CONDITIONS THROUGH THE END OF THE FORECAST PERIOD. WINDS AND
SEAS COULD INCREASE IF THE LOW MOVES CLOSER TO THE AREA DURING THIS
TIME...BUT THERE IS NOT ENOUGH CONFIDENCE IN THE FORECAST TO SAY AT
THIS POINT.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS ALL BEACHES TODAY AS
THE LOW-LEVEL FLOW TIPS NORTHEAST AND COMBINE WITH ELEVATED SEAS
AND LINGERING ASTRONOMICAL INFLUENCES. STRONG NORTHEAST WINDS AND
LINGERING ASTRONOMICAL INFLUENCES WILL RESULT IN AN ENHANCED RISK
OF RIP CURRENTS THROUGH AT LEAST FRIDAY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...BSH
LONG TERM...BSH
AVIATION...
MARINE...BSH








000
FXUS62 KCHS 160510
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
110 AM EDT WED APR 16 2014

.SYNOPSIS...
UNSEASONABLY COOL HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT
AND CONTINUE THROUGH THURSDAY. A WAVE OF LOW PRESSURE COULD
IMPACT THE AREA AS IT PASSES NORTHEAST ACROSS THE NEARBY ATLANTIC
LATE IN THE WEEK...BEFORE HIGH PRESSURE RETURNS FOR EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE COLD FRONT WAS WELL OFFSHORE AND HIGH PRESSURE IS QUICKLY
BUILDING INTO THE REGION. STRONG COLD AIR ADVECTION SUPPORTING
BREEZY CONDITIONS ACROSS EASTERN SOUTH CAROLINA OVERNIGHT...
OCCASIONALLY GUSTY CONDITIONS FURTHER SOUTH OVER GEORGIA AWAY
FROM THE MAIN AXIS OF SURFACE PRES RISES. TEMPERATURES WERE
STEADILY FALLING INTO/TOWARD THE 40S. LOWS FROM THE UPPER 30S
INLAND TO THE MID-UPPER 40S AT THE COAST LOOK ON TRACK. GUSTY
NORTH WINDS WILL PRODUCE WIND CHILLS IN THE UPPER 20S INLAND TO
MID-UPPER 30S COAST.

A FINAL AREA OF STRATOCUMULUS ACROSS SE SOUTH CAROLINA SHOULD
DISSIPATE OR MOVE OFFSHORE IN THE NEXT FEW HOURS. OTHERWISE...
ONLY SCATTERED/THIN HIGH CLOUDS LINGER.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND DECENT MIXING ACROSS
LAKE MOULTRIE SUPPORTING A LAKE WIND ADVISORY OVERNIGHT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
UNSEASONABLY COOL HIGH PRESSURE WILL PERSIST NORTH OF THE AREA INTO
FRIDAY DRY WITH MAINLY DRY CONDITIONS THROUGH AT LEAST THURSDAY.
DEEP MOISTURE COULD CREEP BACK INTO THE AREA FROM THE SOUTH BY
FRIDAY LEADING TO A BETTER CHANCE OF SHOWERS...ESPECIALLY FRIDAY AS
LOW PRESSURE LIKELY MOVES NORTHEAST OFFSHORE. THERE IS SOME
UNCERTAINTY REGARDING THE STRENGTH OF THE UPPER TROUGH AND THE
ASSOCIATED SURFACE LOW AND AS A RESULT THE LOW/S PROXIMITY TO THE
COAST. AT THE VERY LEAST A DECENT PRESSURE GRADIENT WILL PERSIST
OVER THE AREA BETWEEN THE HIGH TO THE NORTH AND LOW PRESSURE TO THE
SOUTH AND EAST. THIS WILL YIELD BREEZY CONDITIONS...ESPECIALLY NEAR
THE COAST...AND ENOUGH TO WARRANT A LAKE WIND ADVISORY INTO
WEDNESDAY. TEMPS WILL BE QUITE CHILLY FOR THIS TIME OF YEAR THROUGH
THE PERIOD...ALTHOUGH A SLOW WARM-UP IS EXPECTED WITH TIME. THE
COOLEST TEMPS WILL COME THURSDAY MORNING WHEN INLAND AREAS SHOULD
DROP INTO THE MID TO UPPER 30S...ALTHOUGH LITTLE TO NO FROST IS
EXPECTED GIVEN THE ELEVATED WINDS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
MVFR CIGS AT KCHS SHOULD BE OUT OF THE PICTURE BETWEEN 06Z-08Z IF
NOT SOONER. OTHERWISE VFR CONDITIONS AT BOTH KSAV AND KCHS THROUGH
06Z THURSDAY. THE MAIN ISSUE TODAY WITH BE GUSTY N TO NE SURFACE
WINDS IN THE 20-25 KT RANGE THROUGH MID AFTERNOON.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TONIGHT...WINDS AT 41008 ARE ALREADY GUSTING TO GALE FORCE AND
WITH PRESSURES STILL RISING OVER CENTRAL SOUTH CAROLINA BEHIND THE
SECONDARY COLD FRONT...IT APPEARS WINDS WILL INCREASE TO 30 KT
WITH GUSTS TO 40 KT OVER THE GEORGIA OFFSHORE WATERS OVER THE NEXT
FEW HOURS. THE SMALL CRAFT ADVISORY HAS THEREFORE BEEN UPGRADED TO
A GALE WARNING THROUGH SUNRISE WEDNESDAY. SMALL CRAFT ADVISORIES
REMAIN IN EFFECT FOR THE NEARSHORE WATERS...INCLUDING THE
CHARLESTON HARBOR.

WEDNESDAY THROUGH SUNDAY...A STRONG PRESSURE GRADIENT WILL REMAIN IN
PLACE INTO LATE WEEK AS COOL HIGH PRESSURE BUILDS FROM THE NORTH AND
LOW PRESSURE PASSES BY TO THE SOUTH AND EAST FRIDAY INTO SATURDAY.
THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO THURSDAY FOR
CHARLESTON HARBOR...AND INTO AT LEAST FRIDAY ELSEWHERE UNTIL THE LOW
PASSES BY. COULD BE A FEW GALE FORCE GUSTS FROM TIME TO TIME BUT DO
NOT ANTICIPATE ANY GALE WARNINGS. THERE IS STILL SOME UNCERTAINTY
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS MARINERS
SHOULD CONTINUE TO MONITOR THE FORECAST FOR LATE WEEK AS CONDITIONS
COULD POSSIBLY BE MUCH WORSE THAN CURRENTLY FORECAST.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS ALL BEACHES
WEDNESDAY AS THE LOW-LEVEL FLOW TIPS NORTHEAST AND COMBINE WITH
ELEVATED SEAS AND LINGERING ASTRONOMICAL INFLUENCES. AND ELEVATED
RISK FOR RIP CURRENTS WILL LINGER THROUGH MUCH OF THE WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

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








000
FXUS62 KCHS 160240
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1040 PM EDT TUE APR 15 2014

...GALE WARNING ISSUED FOR THE GEORGIA OFFSHORE WATERS UNTIL 8 AM
WEDNESDAY...

.SYNOPSIS...
UNSEASONABLY COOL HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT
AND CONTINUE THROUGH THURSDAY. A WAVE OF LOW PRESSURE COULD
IMPACT THE AREA AS IT PASSES NORTHEAST ACROSS THE NEARBY ATLANTIC
LATE IN THE WEEK...BEFORE HIGH PRESSURE RETURNS FOR EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE COLD FRONT IS NOW OFFSHORE AND POISED TO MOVE ACROSS BUOY
41004 BY 10 PM. HIGH PRESSURE IS QUICKLY BUILDING INTO THE REGION
IN THE WAKE OF THE FRONT WITH STRONG COLD AIR ADVECTION SUPPORTING
BREEZY CONDITIONS. TEMPERATURES ARE STEADILY FALLING WITH 16/01Z
TEMPERATURES RANGING FROM THE LOWER 50S ACROSS INTERIOR SOUTHEAST
GEORGIA TO THE LOWER 60S AT THE COAST AND ACROSS PORTIONS OF THE
CHARLESTON TRI-COUNTY AREA. LOWS FROM THE UPPER 30S INLAND TO THE
MID-UPPER 40S AT THE COAST LOOK ON TRACK. GUSTY NORTH WINDS WILL
PRODUCE WIND CHILLS IN THE UPPER 20S INLAND TO MID-UPPER 30S
COAST...WHICH IS DOWNRIGHT CHILLY FOR MID-APRIL.

LOW AND MID-LEVEL CLOUDS ARE QUICKLY SCOURING OUT AS DOWNSLOPE
TRAJECTORIES TAKE HOLD...HOWEVER CIRRUS ASSOCIATED WITH THE RIGHT
ENTRANCE REGION OF A 120 KT JET CURRENTLY ROUNDING THE BASE OF THE
UPPER TROUGH WILL SUPPORT PARTLY CLOUDY SKIES THROUGH VERY EARLY
WEDNESDAY MORNING BEFORE PUSHING OFFSHORE AS THE UPPER TROUGH
SWINGS BY. DRY WEATHER WILL PREVAIL FOR THE REST OF THE NIGHT.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND DECENT MIXING ACROSS
LAKE MOULTRIE WILL SUPPORT IN A LAKE WIND ADVISORY THROUGH EARLY
WEDNESDAY AFTERNOON.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
UNSEASONABLY COOL HIGH PRESSURE WILL PERSIST NORTH OF THE AREA INTO
FRIDAY DRY WITH MAINLY DRY CONDITIONS THROUGH AT LEAST THURSDAY.
DEEP MOISTURE COULD CREEP BACK INTO THE AREA FROM THE SOUTH BY
FRIDAY LEADING TO A BETTER CHANCE OF SHOWERS...ESPECIALLY FRIDAY AS
LOW PRESSURE LIKELY MOVES NORTHEAST OFFSHORE. THERE IS SOME
UNCERTAINTY REGARDING THE STRENGTH OF THE UPPER TROUGH AND THE
ASSOCIATED SURFACE LOW AND AS A RESULT THE LOW/S PROXIMITY TO THE
COAST. AT THE VERY LEAST A DECENT PRESSURE GRADIENT WILL PERSIST
OVER THE AREA BETWEEN THE HIGH TO THE NORTH AND LOW PRESSURE TO THE
SOUTH AND EAST. THIS WILL YIELD BREEZY CONDITIONS...ESPECIALLY NEAR
THE COAST...AND ENOUGH TO WARRANT A LAKE WIND ADVISORY INTO
WEDNESDAY. TEMPS WILL BE QUITE CHILLY FOR THIS TIME OF YEAR THROUGH
THE PERIOD...ALTHOUGH A SLOW WARM-UP IS EXPECTED WITH TIME. THE
COOLEST TEMPS WILL COME THURSDAY MORNING WHEN INLAND AREAS SHOULD
DROP INTO THE MID TO UPPER 30S...ALTHOUGH LITTLE TO NO FROST IS
EXPECTED GIVEN THE ELEVATED WINDS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
THE DISTINCT LINE OF SHOWERS HAS MOVED EAST OF THE
TERMINALS...LEAVING SOME TRAILING STRATUS BEHIND. CLOUDS SHOULD
CLEAR OUT WITHIN THE FIRST COUPLE OF HOURS AS DRIER AIR FILTERS
IN...OTHERWISE VFR. WINDS WILL REMAIN GUSTY DUE TO THE PRESSURE
GRADIENT BETWEEN THE DEPARTING LOW AND THE STRONG HIGH BUILDING IN
FROM THE NORTHWEST. WINDS WILL CONTINUE TO SHIFT TO A MORE NORTHERLY
DIRECTION THROUGHOUT THE NIGHT BEFORE SETTLING DOWN AT THE END OF
THE TAF PERIOD.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TONIGHT...WINDS AT 41008 ARE ALREADY GUSTING TO GALE FORCE AND
WITH PRESSURES STILL RISING OVER CENTRAL SOUTH CAROLINA BEHIND THE
SECONDARY COLD FRONT...IT APPEARS WINDS WILL INCREASE TO 30 KT
WITH GUSTS TO 40 KT OVER THE GEORGIA OFFSHORE WATERS OVER THE NEXT
FEW HOURS. THE SMALL CRAFT ADVISORY HAS THEREFORE BEEN UPGRADED TO
A GALE WARNING THROUGH SUNRISE WEDNESDAY. SMALL CRAFT ADVISORIES
REMAIN IN EFFECT FOR THE NEARSHORE WATERS...INCLUDING THE
CHARLESTON HARBOR.

WEDNESDAY THROUGH SUNDAY...A STRONG PRESSURE GRADIENT WILL REMAIN IN
PLACE INTO LATE WEEK AS COOL HIGH PRESSURE BUILDS FROM THE NORTH AND
LOW PRESSURE PASSES BY TO THE SOUTH AND EAST FRIDAY INTO SATURDAY.
THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO THURSDAY FOR
CHARLESTON HARBOR...AND INTO AT LEAST FRIDAY ELSEWHERE UNTIL THE LOW
PASSES BY. COULD BE A FEW GALE FORCE GUSTS FROM TIME TO TIME BUT DO
NOT ANTICIPATE ANY GALE WARNINGS. THERE IS STILL SOME UNCERTAINTY
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS MARINERS
SHOULD CONTINUE TO MONITOR THE FORECAST FOR LATE WEEK AS CONDITIONS
COULD POSSIBLY BE MUCH WORSE THAN CURRENTLY FORECAST.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS ALL BEACHES
WEDNESDAY AS THE LOW-LEVEL FLOW TIPS NORTHEAST AND COMBINE WITH
ELEVATED SEAS AND LINGERING ASTRONOMICAL INFLUENCES. AND ELEVATED
RISK FOR RIP CURRENTS WILL LINGER THROUGH MUCH OF THE WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     GALE WARNING UNTIL 8 AM EDT WEDNESDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

ST







000
FXUS62 KCHS 160140
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
940 PM EDT TUE APR 15 2014

.SYNOPSIS...
UNSEASONABLY COOL HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT
AND CONTINUE THROUGH THURSDAY. A WAVE OF LOW PRESSURE COULD
IMPACT THE AREA AS IT PASSES NORTHEAST ACROSS THE NEARBY ATLANTIC
LATE IN THE WEEK...BEFORE HIGH PRESSURE RETURNS FOR EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE COLD FRONT IS NOW OFFSHORE AND POISED TO MOVE ACROSS BUOY
41004 BY 10 PM. HIGH PRESSURE IS QUICKLY BUILDING INTO THE REGION
IN THE WAKE OF THE FRONT WITH STRONG COLD AIR ADVECTION SUPPORTING
BREEZY CONDITIONS. TEMPERATURES ARE STEADILY FALLING WITH 16/01Z
TEMPERATURES RANGING FROM THE LOWER 50S ACROSS INTERIOR SOUTHEAST
GEORGIA TO THE LOWER 60S AT THE COAST AND ACROSS PORTIONS OF THE
CHARLESTON TRI-COUNTY AREA. LOWS FROM THE UPPER 30S INLAND TO THE
MID-UPPER 40S AT THE COAST LOOK ON TRACK. GUSTY NORTH WINDS WILL
PRODUCE WIND CHILLS IN THE UPPER 20S INLAND TO MID-UPPER 30S
COAST...WHICH IS DOWNRIGHT CHILLY FOR MID-APRIL.

LOW AND MID-LEVEL CLOUDS ARE QUICKLY SCOURING OUT AS DOWNSLOPE
TRAJECTORIES TAKE HOLD...HOWEVER CIRRUS ASSOCIATED WITH THE RIGHT
ENTRANCE REGION OF A 120 KT JET CURRENTLY ROUNDING THE BASE OF THE
UPPER TROUGH WILL SUPPORT PARTLY CLOUDY SKIES THROUGH VERY EARLY
WEDNESDAY MORNING BEFORE PUSHING OFFSHORE AS THE UPPER TROUGH
SWINGS BY. DRY WEATHER WILL PREVAIL FOR THE REST OF THE NIGHT.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND DECENT MIXING ACROSS
LAKE MOULTRIE WILL SUPPORT IN A LAKE WIND ADVISORY THROUGH EARLY
WEDNESDAY AFTERNOON.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
UNSEASONABLY COOL HIGH PRESSURE WILL PERSIST NORTH OF THE AREA INTO
FRIDAY DRY WITH MAINLY DRY CONDITIONS THROUGH AT LEAST THURSDAY.
DEEP MOISTURE COULD CREEP BACK INTO THE AREA FROM THE SOUTH BY
FRIDAY LEADING TO A BETTER CHANCE OF SHOWERS...ESPECIALLY FRIDAY AS
LOW PRESSURE LIKELY MOVES NORTHEAST OFFSHORE. THERE IS SOME
UNCERTAINTY REGARDING THE STRENGTH OF THE UPPER TROUGH AND THE
ASSOCIATED SURFACE LOW AND AS A RESULT THE LOW/S PROXIMITY TO THE
COAST. AT THE VERY LEAST A DECENT PRESSURE GRADIENT WILL PERSIST
OVER THE AREA BETWEEN THE HIGH TO THE NORTH AND LOW PRESSURE TO THE
SOUTH AND EAST. THIS WILL YIELD BREEZY CONDITIONS...ESPECIALLY NEAR
THE COAST...AND ENOUGH TO WARRANT A LAKE WIND ADVISORY INTO
WEDNESDAY. TEMPS WILL BE QUITE CHILLY FOR THIS TIME OF YEAR THROUGH
THE PERIOD...ALTHOUGH A SLOW WARM-UP IS EXPECTED WITH TIME. THE
COOLEST TEMPS WILL COME THURSDAY MORNING WHEN INLAND AREAS SHOULD
DROP INTO THE MID TO UPPER 30S...ALTHOUGH LITTLE TO NO FROST IS
EXPECTED GIVEN THE ELEVATED WINDS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
THE DISTINCT LINE OF SHOWERS HAS MOVED EAST OF THE
TERMINALS...LEAVING SOME TRAILING STRATUS BEHIND. CLOUDS SHOULD
CLEAR OUT WITHIN THE FIRST COUPLE OF HOURS AS DRIER AIR FILTERS
IN...OTHERWISE VFR. WINDS WILL REMAIN GUSTY DUE TO THE PRESSURE
GRADIENT BETWEEN THE DEPARTING LOW AND THE STRONG HIGH BUILDING IN
FROM THE NORTHWEST. WINDS WILL CONTINUE TO SHIFT TO A MORE NORTHERLY
DIRECTION THROUGHOUT THE NIGHT BEFORE SETTLING DOWN AT THE END OF
THE TAF PERIOD.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TONIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL DETERIORATE AS
THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT
AND NORTH WINDS SURGE IN ITS WAKE. SOUTHWEST TO WEST WINDS WILL
BECOME 20 TO 25 KT FOR THE MAJORITY OF THE WATERS. THE COLD FRONT
WILL MOVE INTO THE WATERS THIS EVENING AND PROGRESS FARTHER EAST
OVERNIGHT...WITH HIGH PRESSURE BUILDING INTO THE REGION AND WINDS
BECOMING MORE NORTH. THIS NORTHERLY SURGE WILL BRING WINDS INTO
THE 25 TO 30 KT RANGE. THERE IS A LOW CHANCE FOR AN ISOLATED GUST
TO GALE FORCE BEYOND 10 TO 15 NM...BUT THE PROBABILITIES ARE TOO
LOW FOR GALE WARNINGS AT THIS TIME.

WEDNESDAY THROUGH SUNDAY...A STRONG PRESSURE GRADIENT WILL REMAIN IN
PLACE INTO LATE WEEK AS COOL HIGH PRESSURE BUILDS FROM THE NORTH AND
LOW PRESSURE PASSES BY TO THE SOUTH AND EAST FRIDAY INTO SATURDAY.
THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO THURSDAY FOR
CHARLESTON HARBOR...AND INTO AT LEAST FRIDAY ELSEWHERE UNTIL THE LOW
PASSES BY. COULD BE A FEW GALE FORCE GUSTS FROM TIME TO TIME BUT DO
NOT ANTICIPATE ANY GALE WARNINGS. THERE IS STILL SOME UNCERTAINTY
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS MARINERS
SHOULD CONTINUE TO MONITOR THE FORECAST FOR LATE WEEK AS CONDITIONS
COULD POSSIBLY BE MUCH WORSE THAN CURRENTLY FORECAST.

RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS ALL BEACHES
WEDNESDAY AS THE LOW-LEVEL FLOW TIPS NORTHEAST AND COMBINE WITH
ELEVATED SEAS AND LINGERING ASTRONOMICAL INFLUENCES. AND ELEVATED
RISK FOR RIP CURRENTS WILL LINGER THROUGH MUCH OF THE WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

ST







000
FXUS62 KCHS 160002
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
802 PM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING AND
OFF THE COAST TONIGHT. UNSEASONABLY COOL HIGH PRESSURE WILL
FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH THURSDAY. A WAVE OF
LOW PRESSURE COULD IMPACT THE AREA AS IT PASSES NORTHEAST ACROSS
THE NEARBY ATLANTIC LATE IN THE WEEK...BEFORE HIGH PRESSURE
RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AT 15/22Z...THE COLD FRONT EXTENDED FROM ROUGHLY MANNING TO
WALTERBORO...BEAUFORT...TYBEE ISLAND TO JUST OFFSHORE OF SAINT
SIMMONS. THE FRONT IS MOVING RAPIDLY EAST AT 30 KT AND WILL BE
OFFSHORE OF THE CHARLESTON COUNTY COAST BY 8-9 PM. A LINE OF
SHOWERS WITH GUSTY WINDS NEAR 40 MPH ACCOMPANY THE FRONT AND WILL
IMPACT MUCH OF THE CHARLESTON TRI-COUNTY AREA DURING THE NEXT 2
HOURS OR SO. ADJUSTED NEAR TERM POPS TO TAKE CURRENT RADAR TRENDS
INTO ACCOUNT...MAXING GRIDDED POPS AT 70 PERCENT ALONG AND AHEAD
OF THE FRONT. ONCE THE FRONT PASSES...THE RISK FOR MEASURABLE
RAINFALL WILL END.

SATELLITE SHOWS AN IMPRESSIVE DOWNSLOPE SIGNATURE WITH SKIES
RAPIDLY CLEARING ACROSS EASTERN GEORGIA...THE UPSTATE...CSRA AND
WESTERN PORTIONS OF THE MIDLANDS. THIS CLEARING WILL ENCOMPASS THE
FORECAST AREA THROUGH THE EVENING WITH CLEAR SKIES DOMINATING
AFTER 9-10 PM. BREEZY NORTH WINDS WILL DEVELOP BEHIND THE
SECONDARY FRONT THAT IS MOVING RAPIDLY SOUTH THROUGH THE NORTHERN
MIDLANDS. TEMPERATURES LOOK TO DROP A GOOD 15 DEGREES INITIALLY
WITH THE INITIAL FRONTAL PASSAGE AND WILL BOTTOM OUT IN THE UPPER
30S INLAND TO THE UPPER 40S/LOWER 50S AT THE BEACHES PRIOR TO
SUNRISE WEDNESDAY. BREEZY CONDITIONS WILL ALLOW WIND CHILLS TO
DROP INTO THE UPPER 20S TO MID 30S WHICH IS RATHER CHILLY FOR MID
APRIL.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND DECENT MIXING ACROSS
LAKE MOULTRIE WILL SUPPORT IN A LAKE WIND ADVISORY THROUGH EARLY
WEDNESDAY AFTERNOON.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
UNSEASONABLY COOL HIGH PRESSURE WILL PERSIST NORTH OF THE AREA INTO
FRIDAY DRY WITH MAINLY DRY CONDITIONS THROUGH AT LEAST THURSDAY.
DEEP MOISTURE COULD CREEP BACK INTO THE AREA FROM THE SOUTH BY
FRIDAY LEADING TO A BETTER CHANCE OF SHOWERS...ESPECIALLY FRIDAY AS
LOW PRESSURE LIKELY MOVES NORTHEAST OFFSHORE. THERE IS SOME
UNCERTAINTY REGARDING THE STRENGTH OF THE UPPER TROUGH AND THE
ASSOCIATED SURFACE LOW AND AS A RESULT THE LOW/S PROXIMITY TO THE
COAST. AT THE VERY LEAST A DECENT PRESSURE GRADIENT WILL PERSIST
OVER THE AREA BETWEEN THE HIGH TO THE NORTH AND LOW PRESSURE TO THE
SOUTH AND EAST. THIS WILL YIELD BREEZY CONDITIONS...ESPECIALLY NEAR
THE COAST...AND ENOUGH TO WARRANT A LAKE WIND ADVISORY INTO
WEDNESDAY. TEMPS WILL BE QUITE CHILLY FOR THIS TIME OF YEAR THROUGH
THE PERIOD...ALTHOUGH A SLOW WARM-UP IS EXPECTED WITH TIME. THE
COOLEST TEMPS WILL COME THURSDAY MORNING WHEN INLAND AREAS SHOULD
DROP INTO THE MID TO UPPER 30S...ALTHOUGH LITTLE TO NO FROST IS
EXPECTED GIVEN THE ELEVATED WINDS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
THE DISTINCT LINE OF SHOWERS HAS MOVED EAST OF THE
TERMINALS...LEAVING SOME TRAILING STRATUS BEHIND. CLOUDS SHOULD
CLEAR OUT WITHIN THE FIRST COUPLE OF HOURS AS DRIER AIR FILTERS
IN...OTHERWISE VFR. WINDS WILL REMAIN GUSTY DUE TO THE PRESSURE
GRADIENT BETWEEN THE DEPARTING LOW AND THE STRONG HIGH BUILDING IN
FROM THE NORTHWEST. WINDS WILL CONTINUE TO SHIFT TO A MORE NORTHERLY
DIRECTION THROUGHOUT THE NIGHT BEFORE SETTLING DOWN AT THE END OF
THE TAF PERIOD.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TONIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL DETERIORATE AS
THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT
AND NORTH WINDS SURGE IN ITS WAKE. SOUTHWEST TO WEST WINDS WILL
BECOME 20 TO 25 KT FOR THE MAJORITY OF THE WATERS. THE COLD FRONT
WILL MOVE INTO THE WATERS THIS EVENING AND PROGRESS FARTHER EAST
OVERNIGHT...WITH HIGH PRESSURE BUILDING INTO THE REGION AND WINDS
BECOMING MORE NORTH. THIS NORTHERLY SURGE WILL BRING WINDS INTO
THE 25 TO 30 KT RANGE. THERE IS A LOW CHANCE FOR AN ISOLATED GUST
TO GALE FORCE BEYOND 10 TO 15 NM...BUT THE PROBABILITIES ARE TOO
LOW FOR GALE WARNINGS AT THIS TIME.

WEDNESDAY THROUGH SUNDAY...A STRONG PRESSURE GRADIENT WILL REMAIN IN
PLACE INTO LATE WEEK AS COOL HIGH PRESSURE BUILDS FROM THE NORTH AND
LOW PRESSURE PASSES BY TO THE SOUTH AND EAST FRIDAY INTO SATURDAY.
THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO THURSDAY FOR
CHARLESTON HARBOR...AND INTO AT LEAST FRIDAY ELSEWHERE UNTIL THE LOW
PASSES BY. COULD BE A FEW GALE FORCE GUSTS FROM TIME TO TIME BUT DO
NOT ANTICIPATE ANY GALE WARNINGS. THERE IS STILL SOME UNCERTAINTY
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS MARINERS
SHOULD CONTINUE TO MONITOR THE FORECAST FOR LATE WEEK AS CONDITIONS
COULD POSSIBLY BE MUCH WORSE THAN CURRENTLY FORECAST.

RIP CURRENTS...STRONG SOUTHWEST WINDS AND THE FULL MOON SUPPORTS A
HIGH RISK FOR SC BEACHES AND A MODERATE RISK FOR GA BEACHES TODAY.
AN ENHANCED RISK OF RIP CURRENTS WILL PERSIST THROUGH LATE
WEEK...THE RESULT OF ELEVATED SURF AND MODERATE TO STRONG
NORTHEAST WINDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

ST/BDC







000
FXUS62 KCHS 152213
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
613 PM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING AND
OFF THE COAST TONIGHT. UNSEASONABLY COOL HIGH PRESSURE WILL
FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH THURSDAY. A WAVE OF
LOW PRESSURE COULD IMPACT THE AREA AS IT PASSES NORTHEAST ACROSS
THE NEARBY ATLANTIC LATE IN THE WEEK...BEFORE HIGH PRESSURE
RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AT 15/22Z...THE COLD FRONT EXTENDED FROM ROUGHLY MANNING TO
WALTERBORO...BEAUFORT...TYBEE ISLAND TO JUST OFFSHORE OF SAINT
SIMMONS. THE FRONT IS MOVING RAPIDLY EAST AT 30 KT AND WILL BE
OFFSHORE OF THE CHARLESTON COUNTY COAST BY 8-9 PM. A LINE OF
SHOWERS WITH GUSTY WINDS NEAR 40 MPH ACCOMPANY THE FRONT AND WILL
IMPACT MUCH OF THE CHARLESTON TRI-COUNTY AREA DURING THE NEXT 2
HOURS OR SO. ADJUSTED NEAR TERM POPS TO TAKE CURRENT RADAR TRENDS
INTO ACCOUNT...MAXING GRIDDED POPS AT 70 PERCENT ALONG AND AHEAD
OF THE FRONT. ONCE THE FRONT PASSES...THE RISK FOR MEASURABLE
RAINFALL WILL END.

SATELLITE SHOWS AN IMPRESSIVE DOWNSLOPE SIGNATURE WITH SKIES
RAPIDLY CLEARING ACROSS EASTERN GEORGIA...THE UPSTATE...CSRA AND
WESTERN PORTIONS OF THE MIDLANDS. THIS CLEARING WILL ENCOMPASS THE
FORECAST AREA THROUGH THE EVENING WITH CLEAR SKIES DOMINATING
AFTER 9-10 PM. BREEZY NORTH WINDS WILL DEVELOP BEHIND THE
SECONDARY FRONT THAT IS MOVING RAPIDLY SOUTH THROUGH THE NORTHERN
MIDLANDS. TEMPERATURES LOOK TO DROP A GOOD 15 DEGREES INITIALLY
WITH THE INITIAL FRONTAL PASSAGE AND WILL BOTTOM OUT IN THE UPPER
30S INLAND TO THE UPPER 40S/LOWER 50S AT THE BEACHES PRIOR TO
SUNRISE WEDNESDAY. BREEZY CONDITIONS WILL ALLOW WIND CHILLS TO
DROP INTO THE UPPER 20S TO MID 30S WHICH IS RATHER CHILLY FOR MID
APRIL.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND DECENT MIXING ACROSS
LAKE MOULTRIE WILL SUPPORT IN A LAKE WIND ADVISORY THROUGH EARLY
WEDNESDAY AFTERNOON.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
UNSEASONABLY COOL HIGH PRESSURE WILL PERSIST NORTH OF THE AREA INTO
FRIDAY DRY WITH MAINLY DRY CONDITIONS THROUGH AT LEAST THURSDAY.
DEEP MOISTURE COULD CREEP BACK INTO THE AREA FROM THE SOUTH BY
FRIDAY LEADING TO A BETTER CHANCE OF SHOWERS...ESPECIALLY FRIDAY AS
LOW PRESSURE LIKELY MOVES NORTHEAST OFFSHORE. THERE IS SOME
UNCERTAINTY REGARDING THE STRENGTH OF THE UPPER TROUGH AND THE
ASSOCIATED SURFACE LOW AND AS A RESULT THE LOW/S PROXIMITY TO THE
COAST. AT THE VERY LEAST A DECENT PRESSURE GRADIENT WILL PERSIST
OVER THE AREA BETWEEN THE HIGH TO THE NORTH AND LOW PRESSURE TO THE
SOUTH AND EAST. THIS WILL YIELD BREEZY CONDITIONS...ESPECIALLY NEAR
THE COAST...AND ENOUGH TO WARRANT A LAKE WIND ADVISORY INTO
WEDNESDAY. TEMPS WILL BE QUITE CHILLY FOR THIS TIME OF YEAR THROUGH
THE PERIOD...ALTHOUGH A SLOW WARM-UP IS EXPECTED WITH TIME. THE
COOLEST TEMPS WILL COME THURSDAY MORNING WHEN INLAND AREAS SHOULD
DROP INTO THE MID TO UPPER 30S...ALTHOUGH LITTLE TO NO FROST IS
EXPECTED GIVEN THE ELEVATED WINDS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
TO BE ISSUED.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TONIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL DETERIORATE AS
THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT
AND NORTH WINDS SURGE IN ITS WAKE. SOUTHWEST TO WEST WINDS WILL
BECOME 20 TO 25 KT FOR THE MAJORITY OF THE WATERS. THE COLD FRONT
WILL MOVE INTO THE WATERS THIS EVENING AND PROGRESS FARTHER EAST
OVERNIGHT...WITH HIGH PRESSURE BUILDING INTO THE REGION AND WINDS
BECOMING MORE NORTH. THIS NORTHERLY SURGE WILL BRING WINDS INTO
THE 25 TO 30 KT RANGE. THERE IS A LOW CHANCE FOR AN ISOLATED GUST
TO GALE FORCE BEYOND 10 TO 15 NM...BUT THE PROBABILITIES ARE TOO
LOW FOR GALE WARNINGS AT THIS TIME.

WEDNESDAY THROUGH SUNDAY...A STRONG PRESSURE GRADIENT WILL REMAIN IN
PLACE INTO LATE WEEK AS COOL HIGH PRESSURE BUILDS FROM THE NORTH AND
LOW PRESSURE PASSES BY TO THE SOUTH AND EAST FRIDAY INTO SATURDAY.
THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO THURSDAY FOR
CHARLESTON HARBOR...AND INTO AT LEAST FRIDAY ELSEWHERE UNTIL THE LOW
PASSES BY. COULD BE A FEW GALE FORCE GUSTS FROM TIME TO TIME BUT DO
NOT ANTICIPATE ANY GALE WARNINGS. THERE IS STILL SOME UNCERTAINTY
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS MARINERS
SHOULD CONTINUE TO MONITOR THE FORECAST FOR LATE WEEK AS CONDITIONS
COULD POSSIBLY BE MUCH WORSE THAN CURRENTLY FORECAST.

RIP CURRENTS...STRONG SOUTHWEST WINDS AND THE FULL MOON SUPPORTS A
HIGH RISK FOR SC BEACHES AND A MODERATE RISK FOR GA BEACHES TODAY.
AN ENHANCED RISK OF RIP CURRENTS WILL PERSIST THROUGH LATE
WEEK...THE RESULT OF ELEVATED SURF AND MODERATE TO STRONG
NORTHEAST WINDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$









000
FXUS62 KCHS 152011
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
411 PM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING AND
OFF THE COAST TONIGHT. UNSEASONABLY COOL HIGH PRESSURE WILL
FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH THURSDAY. A WAVE OF
LOW PRESSURE COULD IMPACT THE AREA AS IT PASSES NORTHEAST ACROSS
THE NEARBY ATLANTIC LATE IN THE WEEK...BEFORE HIGH PRESSURE
RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE REMAINDER OF THE AFTERNOON...THE STRONG COLD FRONT IS
CURRENTLY PROGRESSING INTO THE SOUTHWEST ZONES BY MID TO LATE
AFTERNOON AND ORIENTED NEARLY PARALLEL WITH INTERSTATE 95. THE
BULK OF SHOWER ACTIVITY HAS SHIFTED OFF THE COAST WITH THE
EXCEPTION OF SCATTERED LIGHT RAIN ACROSS COASTAL GEORGIA AND A
LINE OF WEAK CONVECTION ALONG THE IMMEDIATE FRONTAL ZONE. EXPECT
THE SHOWER ACTIVITY ASSOCIATED WITH THE FRONT TO STEADILY SHIFT
THROUGH THE FORECAST AREA DURING THE REMAINDER OF THE AFTERNOON
INTO THE EARLY EVENING HOURS...EVENTUALLY FOLLOWING THE FRONT AS
IT LIFTS EAST/NORTHEAST AND OUT OF THE AREA AROUND SUNSET. DESPITE
IMPRESSIVE UPPER LEVEL DYNAMICS...AS SEEN IN 50 TO 60 KT OF DEEP
LAYER SHEAR...INSTABILITY HAS BEEN LIMITED BY THICK CLOUD COVER
AND CONSISTENT RAIN. CONSIDERING THE LACK OF INSTABILITY TO TAP
INTO THE SIGNIFICANT FORCING IN THE LOW/MID LEVELS...HAVE REMOVED
MENTION OF THUNDER FROM THE FORECAST. BREEZY CONDITIONS ARE
CURRENTLY BEING REPORTED ACROSS THE FORECAST AREA...YET WITH
SUSTAINED WINDS BELOW 25 MPH AND GUSTS BELOW 30 MPH...WIND
ADVISORY CRITERIA IS NOT BEING MET.

TONIGHT...THE COLD FRONT WILL CROSS THE COASTLINE THIS EVENING AND
MOVE OFFSHORE OVERNIGHT...DRIVEN BY THE DAMPENING UPPER TROUGH
ALSO SWEEPING THE EAST COAST. DOWNSLOPE FLOW BEHIND THE FRONT IS
RAPIDLY ERODING CLOUD COVER ACROSS THE UPSTATE REGION...AND EXPECT
SKY COVER TO STEADILY SCATTER/CLEAR FROM WEST TO EAST DURING THE
EVENING TIME FRAME. THE COLD FRONT WILL DELINEATE A SIGNIFICANT
CHANGE IN AIR MASS...AS OBSERVATION SITES IN ITS WAKE HAVE DROPPED
OVER 10 DEGREES IN LESS THAN AN HOUR OF ITS PASSING. COLDER AND
DRIER AIR WILL THUS ALSO ADVECT INTO SOUTHEAST SOUTH CAROLINA AND
GEORGIA TONIGHT...WITH TEMPERATURES FALLING INTO THE UPPER 30S
INLAND TO THE LOWER 40S NEAR THE COAST...MORE THAN 10 DEGREES
BELOW SEASONAL NORMALS. ISALLOBARIC PRESSURE RISES AND A VERY
TIGHT PRESSURE GRADIENT WILL MAINTAIN RATHER BREEZY CONDITIONS
OVERNIGHT...AND WHEN COMBINED WITH COLD TEMPERATURES...WILL
SUPPORT WIND CHILLS BELOW FREEZING.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND DECENT MIXING ACROSS
LAKE MOULTRIE WILL SUPPORT IN A LAKE WIND ADVISORY THROUGH EARLY
WEDNESDAY AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
UNSEASONABLY COOL HIGH PRESSURE WILL PERSIST NORTH OF THE AREA INTO
FRIDAY DRY WITH MAINLY DRY CONDITIONS THROUGH AT LEAST THURSDAY.
DEEP MOISTURE COULD CREEP BACK INTO THE AREA FROM THE SOUTH BY
FRIDAY LEADING TO A BETTER CHANCE OF SHOWERS...ESPECIALLY FRIDAY AS
LOW PRESSURE LIKELY MOVES NORTHEAST OFFSHORE. THERE IS SOME
UNCERTAINTY REGARDING THE STRENGTH OF THE UPPER TROUGH AND THE
ASSOCIATED SURFACE LOW AND AS A RESULT THE LOW/S PROXIMITY TO THE
COAST. AT THE VERY LEAST A DECENT PRESSURE GRADIENT WILL PERSIST
OVER THE AREA BETWEEN THE HIGH TO THE NORTH AND LOW PRESSURE TO THE
SOUTH AND EAST. THIS WILL YIELD BREEZY CONDITIONS...ESPECIALLY NEAR
THE COAST...AND ENOUGH TO WARRANT A LAKE WIND ADVISORY INTO
WEDNESDAY. TEMPS WILL BE QUITE CHILLY FOR THIS TIME OF YEAR THROUGH
THE PERIOD...ALTHOUGH A SLOW WARM-UP IS EXPECTED WITH TIME. THE
COOLEST TEMPS WILL COME THURSDAY MORNING WHEN INLAND AREAS SHOULD
DROP INTO THE MID TO UPPER 30S...ALTHOUGH LITTLE TO NO FROST IS
EXPECTED GIVEN THE ELEVATED WINDS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
MVFR OR LOWER CONDITIONS ARE EXPECTED THROUGH THE EARLY EVENING
BEFORE GRADUALLY IMPROVING TONIGHT. RAIN COVERAGE HAS DIMINISHED
AHEAD OF THE COLD FRONT...YET EXPECT AT LEAST A SLIGHT CHANCE FOR
SHOWERS UNTIL THE FRONT MOVES OFFSHORE THIS EVENING. CEILINGS
WILL BE THE MAIN CAUSE OF PREVAILING FLIGHT RESTRICTIONS...WITH
CURRENT OBSERVATIONS SHOWING A VARIETY OF CLOUD BASES BETWEEN IFR
AND MVFR LEVELS. HAVE ATTEMPTED TO ACCOUNT FOR THESE CONDITIONS IN
THE 18Z TAF ISSUANCE...BUT AMENDMENTS WILL LIKELY BE NEEDED AS
TRENDS PROGRESS. ONCE THE FRONT PASSES...LOW CEILINGS SHOULD
QUICKLY SCATTER WITH CLEAR SKIES EXPECTED BY TONIGHT.

ANOTHER AVIATION CONCERN IS THE WINDS. WIND SPEEDS HAVE BEEN
LOWER THAN INITIALLY EXPECTED...ALTHOUGH IT IS STILL QUITE BREEZY.
SOUTH/SOUTHWEST WINDS AT THE START OF THE PERIOD WILL QUICKLY
SHIFT TO THE NORTHWEST AS THE FRONT MOVES ACROSS THE
TERMINALS...SO HAVE INCLUDED BEST GUESS TIMING OF THE WIND SHIFT
IN THE TAF. MODELS INDICATE THAT WINDS WILL CONTINUE TO BE GUSTY
THROUGH MUCH OF THE REMAINING TAF PERIOD...ALTHOUGH THERE IS SOME
DISCREPANCY AS TO HOW STRONG THE WINDS WILL BE.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TONIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL DETERIORATE AS
THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT
AND NORTH WINDS SURGE IN ITS WAKE. SOUTHWEST TO WEST WINDS WILL
BECOME 20 TO 25 KT FOR THE MAJORITY OF THE WATERS. THE COLD FRONT
WILL MOVE INTO THE WATERS THIS EVENING AND PROGRESS FARTHER EAST
OVERNIGHT...WITH HIGH PRESSURE BUILDING INTO THE REGION AND WINDS
BECOMING MORE NORTH. THIS NORTHERLY SURGE WILL BRING WINDS INTO
THE 25 TO 30 KT RANGE. THERE IS A LOW CHANCE FOR AN ISOLATED GUST
TO GALE FORCE BEYOND 10 TO 15 NM...BUT THE PROBABILITIES ARE TOO
LOW FOR GALE WARNINGS AT THIS TIME.

WEDNESDAY THROUGH SUNDAY...A STRONG PRESSURE GRADIENT WILL REMAIN IN
PLACE INTO LATE WEEK AS COOL HIGH PRESSURE BUILDS FROM THE NORTH AND
LOW PRESSURE PASSES BY TO THE SOUTH AND EAST FRIDAY INTO SATURDAY.
THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO THURSDAY FOR
CHARLESTON HARBOR...AND INTO AT LEAST FRIDAY ELSEWHERE UNTIL THE LOW
PASSES BY. COULD BE A FEW GALE FORCE GUSTS FROM TIME TO TIME BUT DO
NOT ANTICIPATE ANY GALE WARNINGS. THERE IS STILL SOME UNCERTAINTY
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS MARINERS
SHOULD CONTINUE TO MONITOR THE FORECAST FOR LATE WEEK AS CONDITIONS
COULD POSSIBLY BE MUCH WORSE THAN CURRENTLY FORECAST.

RIP CURRENTS...STRONG SOUTHWEST WINDS AND THE FULL MOON SUPPORTS A
HIGH RISK FOR SC BEACHES AND A MODERATE RISK FOR GA BEACHES TODAY.
AN ENHANCED RISK OF RIP CURRENTS WILL PERSIST THROUGH LATE
WEEK...THE RESULT OF ELEVATED SURF AND MODERATE TO STRONG
NORTHEAST WINDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR SCZ045.
     HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR
     SCZ048>051.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

NEAR TERM...WMS
SHORT TERM...RJB
LONG TERM...
AVIATION...ECT/RJB
MARINE...WMS/RJB








000
FXUS62 KCHS 151821
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
221 PM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION TODAY. UNSEASONABLY
COOL HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH
THURSDAY. A WAVE OF LOW PRESSURE COULD IMPACT THE AREA AS IT PASSES
NORTHEAST ACROSS THE NEARBY ATLANTIC LATE IN THE WEEK...BEFORE HIGH
PRESSURE RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONT IS JUST ALONG THE WESTERN PERIPHERY OF THE FORECAST
AREA BY EARLY AFTERNOON...AS SEEN IN RATHER ABRUPT CHANGES IN WIND
DIRECTION AND SIGNIFICANT DROPS IN TEMPERATURES IN ITS WAKE. THE
MAIN SWATH OF PRECIPITATION THAT HAS BEEN AFFECTING THE FORECAST
AREA HAS SHIFTED EAST OVER THE CHARLESTON TRI COUNTY AREA AND
ALONG THE COASTLINE...WITH ANOTHER NARROW LINE OF SHOWER ACTIVITY
RIGHT ALONG THE FRONTAL ZONE TO THE WEST. HAVE MADE SOME
ADJUSTMENTS TO RAIN CHANCES TO ACCOUNT FOR THESE
TRENDS...MAINTAINING HIGH RAIN CHANCES THROUGH THE REMAINDER OF
THE AFTERNOON BEFORE DECREASING POPS FROM SOUTHWEST TO NORTHEAST
INTO THE EVENING. DESPITE IMPRESSIVE UPPER LEVEL DYNAMICS...AS
SEEN IN 50 TO 60 KT OF DEEP LAYER SHEAR...INSTABILITY HAS BEEN
LIMITED BY THICK CLOUD COVER AND CONSISTENT RAIN. CONSIDERING
THE LACK OF INSTABILITY TO TAP INTO THE SIGNIFICANT FORCING IN THE
LOW/MID LEVELS...IT WOULD APPEAR THE ONLY SOLID POTENTIAL FOR
STRONG THUNDERSTORM DEVELOPMENT WOULD BE WHERE ANY CLOUD BREAKS
OCCUR LATER TODAY JUST AHEAD OF THE APPROACHING COLD FRONT. ANY
THUNDERSTORMS THAT CAN INTENSIFY COULD BE CAPABLE OF PRODUCING
DAMAGING WINDS GUSTS AND EVEN AN ISOLATED TORNADO. HOWEVER...STORM
PREDICTION CENTER AGREES WITH A MORE LIMITED POTENTIAL BY TAKING
THE FORECAST AREA OUT OF THE DAY ONE SEVERE WEATHER OUTLOOK. HAVE
ACCOUNTED FOR THESE TRENDS BY LIMITING MENTION OF THUNDER TO JUST
SLIGHT CHANCE FOR THE NEXT FEW HOURS...WHILE ALSO REMOVING SEVERE
WEATHER FROM THE HAZARDOUS WEATHER OUTLOOK.

BREEZY TO GUSTY CONDITIONS ARE CURRENTLY BEING REPORTED ACROSS THE
FORECAST AREA...ESPECIALLY WHERE HEAVIEST RAIN IS OCCURRING IN THE
CHARLESTON TRI COUNTY AREA. DESPITE THESE OBSERVATIONS...SUSTAINED
WINDS HAVE BEEN REMAINED BELOW 25 MPH WITH GUSTS BELOW 30
MPH...AS LIMITED INSTABILITY HAS BEEN UNABLE TO FULLY TAP INTO
HIGHER WINDS ALOFT. SINCE THE EARLY AFTERNOON TIME FRAME HAD THE
BEST WIND POTENTIAL...AND THESE WIND SPEEDS ARE BELOW WIND
ADVISORY CRITERIA...HAVE CANCELLED THE WIND ADVISORY FOR THIS
AFTERNOON.

TEMPERATURES ARE AT THEIR PEAK BY 2 PM...RANGING FROM THE UPPER
60S TO LOWER 70S. EXPECT RATHER RAPID COOLING LATER THIS AFTERNOON
ACROSS SOUTHWEST ZONES AS THE FRONT CROSSES INTO THE AREA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE COLD FRONT WILL PUSH OFF THE COAST AND MUCH DRIER AIR
WILL BEGIN TO FILTER IN FROM THE WEST. SKIES SHOULD CLEAR RAPIDLY
THROUGH THE NIGHT AND WILL BE CLEAR BY THE EARLY MORNING HOURS.
STRENGTHENING HIGH PRESSURE WILL BUILD IN AND RIDGE DOWN THE EAST
SIDE OF THE APPALACHIANS. THE TIGHT NORTHEAST PRESSURE GRADIENT WILL
RESULT IN ABNORMALLY STRONG WINDS FOR THE OVERNIGHT WITH FREQUENT
GUSTS TO 30 MPH EXPECTED THROUGH DAYBREAK. A MUCH COLDER AIR MASS
WILL MOVE IN AND LOWS WILL FALL INTO THE UPPER 30S INLAND...RANGING
TO LOW/MID 40S AT THE COAST. THESE COOL TEMPERATURES COMBINED WITH
THE STRONG AND PERSISTENT NORTHEAST WIND WILL MAKE IT QUITE BLUSTERY
AND WIND CHILLS TO AROUND FREEZING ARE EXPECTED.

WEDNESDAY AND THURSDAY...ROBUST AND STRENGTHENING HIGH PRESSURE WILL
COVER THE AREA EAST OF THE APPALACHIANS...AS IT WEDGES INTO THE SE
PART OF THE COUNTRY. FURTHER OFFSHORE IN THE ATLANTIC WE/LL FIND THE
REMNANTS OF THE COLD FRONT...NOW MORE IN THE SHAPE OF A COASTAL
TROUGH. BETWEEN THESE TWO FEATURES WE LOOK FOR A PINCHING OF THE
PRESSURE PATTERN AND A CONSTANT FEED OF COOL AIR FROM THE NORTH AND
NE. THERE IS EVENTUALLY SOME RETURN FLOW FROM OFF THE OCEAN THAT
WILL FIRST GENERATE SOME MARINE INDUCED STRATOCUMULUS LATE WEDNESDAY
NIGHT AND THURSDAY...WITH MAYBE JUST ENOUGH CONVERGENCE TO PRODUCE
A FEW LOW-TOPPED SHOWERS OVER COASTAL SE GA DURING THURSDAY. THE
TIGHTER PACKING OF THE ISOBARS WILL RESULT IN BREEZY CONDITIONS EACH
DAY INLAND...WITH BREEZY TO WINDY WEATHER THROUGH THE PERIOD CLOSER
TO AND ALONG THE COAST. TEMPS WEDNESDAY WILL BE AT THEIR COOLEST
LEVELS IN ABOUT 3 WEEKS...AND DESPITE THE STRONG APRIL SUNSHINE OUR
MAX TEMPS WILL ONLY ACHIEVE THE LOWER OR MIDDLE 60S AT BEST. IT/S
ANOTHER COOL/CHILLY NIGHT WEDNESDAY NIGHT...ALTHOUGH THE MODERATING
PROCESS BEGINS CLOSER TO THE COAST. THURSDAY WON/T BE AS COOL...BUT
GIVEN A LITTLE GREATER CONCENTRATION OF CLOUDINESS SOUTH AND EAST IT
WILL LIMIT HIGHS TO THE UPPER 60S/LOWER 70S...COOLER ALONG THE
IMMEDIATE COAST.

FRIDAY...A SOUTHERN STREAM SHORT WAVE WILL MOVE INTO THE NE GULF OF
MEXICO...AND DEPENDING UPON WHETHER OR NOT IT PHASES WITH THE
NORTHERN JET WILL DETERMINE WHEN/WHERE AND AT WHAT STRENGTH DOES IT
TRIGGER SURFACE CYCLOGENESIS. CLIMATOLOGY SUGGESTS THIS WILL BE
SOMEWHERE NOT FAR TO OUR SOUTH OR SE. EVEN SO...THE PROXIMITY TO
THESE SYSTEMS AND A NEARBY BAROCLINIC ZONE OVER THE ATLANTIC WILL
COMBINE WITH DEEPER MOISTURE AND ISENTROPIC ASCENT TO PRODUCE AT
LEAST A SLIGHT CHANCE/CHANCE OF SHOWERS. ADJUSTMENTS MAY BE REQUIRED
IN FUTURISTIC FORECASTS ONCE IT BECOMES BETTER DEFINED ON EXACTLY
HOW EVERYTHING WILL UNFOLD. WITH CONSIDERABLE CLOUD COVER AND THE
POTENTIAL FOR SOME WET WEATHER TO ARRIVE...IT/LL BE ANOTHER DAY WITH
MAX TEMPS BELOW SEASONAL NORMS.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND GOOD MIXING ACROSS LAKE
MOULTRIE WILL RESULT IN A LAKE WIND ADVISORY CONTINUING DURING THE
DAY WEDNESDAY...PERHAPS EVEN INTO WEDNESDAY NIGHT OR THURSDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
MVFR OR LOWER CONDITIONS ARE EXPECTED THROUGH THE EARLY EVENING
BEFORE GRADUALLY IMPROVING TONIGHT. RAIN SHOWERS ARE EXPECTED TO
CONTINUE AT THE TERMINALS AHEAD OF AN APPROACHING COLD
FRONT...ALTHOUGH THERE WILL BE BREAKS IN COVERAGE UNTIL THE FRONT
PASSES. CIGS WILL BE THE MAIN CAUSE OF PREVAILING FLIGHT
RESTRICTIONS...WITH CURRENT OBSERVATIONS SHOWING A VARIETY OF CLOUD
BASES BETWEEN IFR AND MVFR LEVELS. HAVE TRIED TO ACCOUNT FOR THESE
CONDITIONS IN THE TAF...BUT AMENDMENTS WILL LIKELY BE NEEDED AS TRENDS
PROGRESS. ONCE THE FRONT PASSES...LOW CIGS SHOULD START TO SCATTER
OUT WITH CLEAR SKIES EXPECTED BY LATE TONIGHT.

ANOTHER AVIATION CONCERN IS THE WINDS. WIND SPEEDS HAVE BEEN A GOOD
BIT LOWER THAN INITIALLY EXPECTED...ALTHOUGH IT IS STILL QUITE
BREEZY. SOUTH/SOUTHWEST WINDS AT THE START OF THE PERIOD WILL
QUICKLY SHIFT TO THE NORTHWEST AS THE FRONT MOVES ACROSS THE
TERMINALS...SO HAVE INCLUDED BEST GUESS TIMING OF THE WIND SHIFT IN
THE TAF. MODELS INDICATE THAT WINDS WILL CONTINUE TO BE GUSTY
THROUGH MUCH OF THE REMAINING TAF PERIOD ALTHOUGH THERE IS SOME
DISCREPANCY AS TO HOW STRONG THE WINDS WILL BE.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TODAY AND TONIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL
DETERIORATE AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN
APPROACHING COLD FRONT. WINDS AND SEAS WILL INCREASE INTO THE
SMALL CRAFT ADVISORY RANGE ACROSS ALL MARINE AREAS BY THIS
AFTERNOON...WHEN SOUTH TO SOUTHWEST WINDS BECOME 20-25 KT
EVERYWHERE. THE COLD FRONT WILL BEGIN TO MOVE INTO THE COASTAL
WATERS IN THE MID AFTERNOON AND PUSH EAST BY THE EVENING.
OVERNIGHT AND BEHIND THE FRONT...HIGH PRESSURE WILL BEGIN TO
BUILD IN AND WINDS WILL TURN MORE NORTH. THIS NORTHERLY SURGE WILL
BRING WINDS INTO THE 25-30 KT RANGE. THERE IS A LOW CHANCE FOR AN
ISOLATED GUST TO GALE FORCE...BUT THE PROBABILITIES ARE LOW ENOUGH
NOT TO ISSUE A GALE WATCH/WARNING FOR NOW. MARINERS ARE ALSO
ADVISED THAT SHOWERS AND POSSIBLY THUNDERSTORMS COULD MOVE INTO
THE LOCAL WATERS THIS AFTERNOON...SOME OF WHICH WILL BE
ACCOMPANIED BY WIND GUSTS UP TO 40 KT...LIGHTNING AND HEAVY RAIN
THAT REDUCES VISIBILITY.

WEDNESDAY THROUGH FRIDAY...A PROLONGED PERIOD WITH SOLID SMALL
CRAFT ADVISORIES IS IN THE OFFING...COURTESY OF AN IMPRESSIVE RIDGE
OF HIGH PRESSURE THAT EXTENDS OVER THE EASTERN SEABOARD. A PACKED
PRESSURE GRADIENT...THE SO-CALLED PINCHING WILL PREVAIL BETWEEN THIS
HUGE HIGH AND A BAROCLINIC ZONE OVER THE ATLANTIC NOT TOO FAR TO THE
EAST AND SE. THIS GENERATES NORTHEASTERLY WINDS OF 20-30 KT ACROSS
THE OPEN ATLANTIC AND 15-20 KT AND FREQUENTLY HIGHER IN CHARLESTON
HARBOR. THIS FAVORABLE FETCH IN TURN KEEPS SEAS ELEVATED...UP TO 8
OR 9 FT ACROSS THE OUTER GA WATERS...AS HIGH AS 6 OR 7 FT WITHIN 20
NM OF THE SHORE AND UP TO 2 FT IN CHARLESTON HARBOR.

FRIDAY NIGHT THROUGH EASTER SUNDAY...A WAVE OF LOW PRESSURE WILL
FORM OVER OR NEAR THE WATERS LATE IN THE WEEK...BEFORE IT PULLS AWAY
AND ALLOWS FOR CONTINENTAL HIGH PRESSURE TO BUILD BACK IN LATER
SATURDAY AND SUNDAY. WIND AND SEA CONDITIONS WON/T BE QUITE AS HARSH
AS EARLIER IN THE WEEK...BUT WE COULD STILL FLIRT WITH SMALL CRAFT
ADVISORIES ACROSS AT LEAST AMZ374.

RIP CURRENTS...STRONG SOUTHWEST WINDS AND THE FULL MOON SUPPORTS A
HIGH RISK FOR SC BEACHES AND A MODERATE RISK FOR GA BEACHES TODAY.
AN ENHANCED RISK OF RIP CURRENTS WILL PERSIST THROUGH LATE
WEEK...THE RESULT OF ELEVATED SURF AND MODERATE TO STRONG
NORTHEAST WINDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR SCZ045.
     HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR
     SCZ048>051.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350-352-
     354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

NEAR TERM...WMS
SHORT TERM...
LONG TERM...
AVIATION...ECT
MARINE...WMS








000
FXUS62 KCHS 151506
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1106 AM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION TODAY. UNSEASONABLY
COOL HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH
THURSDAY. A WAVE OF LOW PRESSURE COULD IMPACT THE AREA AS IT PASSES
NORTHEAST ACROSS THE NEARBY ATLANTIC LATE IN THE WEEK...BEFORE HIGH
PRESSURE RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST MESOANALYSIS PLACES THE STRONG COLD ACROSS FAR WESTERN
NORTH CAROLINA AND FAR WESTERN GEORGIA BY MID MORNING. ABUNDANT
MOISTURE AND FORCING AHEAD OF THE FRONTAL SYSTEM HAS SUPPORTED
WIDESPREAD SHOWERS ACROSS MUCH OF THE SOUTHEAST STATES...WITH
RAIN COVERAGE STEADILY SPREADING ACROSS THE FORECAST AREA DURING
THE PAST FEW HOURS. DESPITE IMPRESSIVE UPPER LEVEL DYNAMICS...AS
SEEN IN 50 TO 60 KT OF DEEP LAYER SHEAR...INSTABILITY HAS BEEN
LIMITED BY THICK CLOUD COVER AND PRE-DAWN RAIN. MOST LIGHTNING
THIS MORNING HAS BEEN FOCUSED ACROSS A CONVECTIVE LINE EXTENDING
FROM SOUTH OF THE ALTAMAHA RIVER INTO THE EASTERN GULF OF
MEXICO...WITH NO LIGHTNING REPORTED AT THIS POINT ACROSS THE
FORECAST AREA WHERE CAPE VALUES ARE WELL BELOW 100 J/KG.
CONSIDERING THE LACK OF INSTABILITY TO TAP INTO THE SIGNIFICANT
FORCING IN THE LOW/MID LEVELS...IT WOULD APPEAR THE ONLY SOLID
POTENTIAL FOR STRONG THUNDERSTORM DEVELOPMENT WOULD BE WHERE ANY
CLOUD BREAKS OCCUR LATER TODAY JUST AHEAD OF THE APPROACHING COLD
FRONT. ANY THUNDERSTORMS THAT CAN INTENSIFY COULD BE CAPABLE OF
PRODUCING DAMAGING WINDS GUSTS AND EVEN AN ISOLATED TORNADO.
HOWEVER...STORM PREDICTION CENTER AGREES WITH A MORE LIMITED
POTENTIAL BY TAKING SOUTH CAROLINA ZONES OUT OF THE DAY ONE SEVERE
WEATHER OUTLOOK AND MAINTAINING SOUTHEAST GEORGIA ZONES TO ACCOUNT
FOR ONGOING CONVECTION FARTHER TO THE SOUTH. HAVE ACCOUNTED FOR
THESE TRENDS BY LIMITING MENTION OF THUNDER TO JUST CHANCE FOR A
FEW HOURS THIS AFTERNOON AND EARLY EVENING WITHIN CATEGORICAL RAIN
COVERAGE.

CONFIDENCE IN WIND POTENTIAL OUTSIDE OF THUNDERSTORMS IS QUITE LOW
WITH THE LATE MORNING UPDATE...AS MODEL GUIDANCE IS PERFORMING
VERY POORLY WHEN COMPARED TO LATEST OBSERVATIONS. FOR SIMILAR
REASONS THAT STRONGER CONVECTION COULD BE SUPPRESSED TODAY...THE
RATHER STABLE AIR MASS CURRENTLY IN PLACE COULD LACK THE ABILITY
TO TAP INTO STRONGER WIND FIELDS JUST ABOVE THE SURFACE. THE BEST
POTENTIAL FOR WIND ADVISORY CRITERIA TO BE MET WOULD BE AFTER
NOON...IF CLOUDS SCATTER ACROSS THE CHARLESTON TRI COUNTY AREA AND
SUPPORT BETTER MIXING INTO THE LOW LEVEL JET. PREFER TO MAINTAIN
THE ADVISORY WITH THIS FORECAST UPDATE TO MONITOR UPSTREAM
OBSERVATIONS AND NEAR TERM TRENDS...YET MAY CONSIDER CANCELING
EARLY IF CONDITIONS CONTINUE TO LOOK UN-CONDUCIVE.

WILL NEED TO ADJUST HOURLY TEMPERATURES TO ACCOUNT FOR COOLER
CONDITIONS GOING INTO THE AFTERNOON PERIOD. HIGH TEMPERATURES WILL
LIKELY RANGE FROM THE UPPER 60S TO MID 70S...WARMEST ACROSS THE
CHARLESTON TRI COUNTY REGION WHERE PRECIPITATION HAS BEEN LESS
PERSISTENT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE COLD FRONT WILL PUSH OFF THE COAST AND MUCH DRIER AIR
WILL BEGIN TO FILTER IN FROM THE WEST. SKIES SHOULD CLEAR RAPIDLY
THROUGH THE NIGHT AND WILL BE CLEAR BY THE EARLY MORNING HOURS.
STRENGTHENING HIGH PRESSURE WILL BUILD IN AND RIDGE DOWN THE EAST
SIDE OF THE APPALACHIANS. THE TIGHT NORTHEAST PRESSURE GRADIENT WILL
RESULT IN ABNORMALLY STRONG WINDS FOR THE OVERNIGHT WITH FREQUENT
GUSTS TO 30 MPH EXPECTED THROUGH DAYBREAK. A MUCH COLDER AIR MASS
WILL MOVE IN AND LOWS WILL FALL INTO THE UPPER 30S INLAND...RANGING
TO LOW/MID 40S AT THE COAST. THESE COOL TEMPERATURES COMBINED WITH
THE STRONG AND PERSISTENT NORTHEAST WIND WILL MAKE IT QUITE BLUSTERY
AND WIND CHILLS TO AROUND FREEZING ARE EXPECTED.

WEDNESDAY AND THURSDAY...ROBUST AND STRENGTHENING HIGH PRESSURE WILL
COVER THE AREA EAST OF THE APPALACHIANS...AS IT WEDGES INTO THE SE
PART OF THE COUNTRY. FURTHER OFFSHORE IN THE ATLANTIC WE/LL FIND THE
REMNANTS OF THE COLD FRONT...NOW MORE IN THE SHAPE OF A COASTAL
TROUGH. BETWEEN THESE TWO FEATURES WE LOOK FOR A PINCHING OF THE
PRESSURE PATTERN AND A CONSTANT FEED OF COOL AIR FROM THE NORTH AND
NE. THERE IS EVENTUALLY SOME RETURN FLOW FROM OFF THE OCEAN THAT
WILL FIRST GENERATE SOME MARINE INDUCED STRATOCUMULUS LATE WEDNESDAY
NIGHT AND THURSDAY...WITH MAYBE JUST ENOUGH CONVERGENCE TO PRODUCE
A FEW LOW-TOPPED SHOWERS OVER COASTAL SE GA DURING THURSDAY. THE
TIGHTER PACKING OF THE ISOBARS WILL RESULT IN BREEZY CONDITIONS EACH
DAY INLAND...WITH BREEZY TO WINDY WEATHER THROUGH THE PERIOD CLOSER
TO AND ALONG THE COAST. TEMPS WEDNESDAY WILL BE AT THEIR COOLEST
LEVELS IN ABOUT 3 WEEKS...AND DESPITE THE STRONG APRIL SUNSHINE OUR
MAX TEMPS WILL ONLY ACHIEVE THE LOWER OR MIDDLE 60S AT BEST. IT/S
ANOTHER COOL/CHILLY NIGHT WEDNESDAY NIGHT...ALTHOUGH THE MODERATING
PROCESS BEGINS CLOSER TO THE COAST. THURSDAY WON/T BE AS COOL...BUT
GIVEN A LITTLE GREATER CONCENTRATION OF CLOUDINESS SOUTH AND EAST IT
WILL LIMIT HIGHS TO THE UPPER 60S/LOWER 70S...COOLER ALONG THE
IMMEDIATE COAST.

FRIDAY...A SOUTHERN STREAM SHORT WAVE WILL MOVE INTO THE NE GULF OF
MEXICO...AND DEPENDING UPON WHETHER OR NOT IT PHASES WITH THE
NORTHERN JET WILL DETERMINE WHEN/WHERE AND AT WHAT STRENGTH DOES IT
TRIGGER SURFACE CYCLOGENESIS. CLIMATOLOGY SUGGESTS THIS WILL BE
SOMEWHERE NOT FAR TO OUR SOUTH OR SE. EVEN SO...THE PROXIMITY TO
THESE SYSTEMS AND A NEARBY BAROCLINIC ZONE OVER THE ATLANTIC WILL
COMBINE WITH DEEPER MOISTURE AND ISENTROPIC ASCENT TO PRODUCE AT
LEAST A SLIGHT CHANCE/CHANCE OF SHOWERS. ADJUSTMENTS MAY BE REQUIRED
IN FUTURISTIC FORECASTS ONCE IT BECOMES BETTER DEFINED ON EXACTLY
HOW EVERYTHING WILL UNFOLD. WITH CONSIDERABLE CLOUD COVER AND THE
POTENTIAL FOR SOME WET WEATHER TO ARRIVE...IT/LL BE ANOTHER DAY WITH
MAX TEMPS BELOW SEASONAL NORMS.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND GOOD MIXING ACROSS LAKE
MOULTRIE WILL RESULT IN A LAKE WIND ADVISORY CONTINUING DURING THE
DAY WEDNESDAY...PERHAPS EVEN INTO WEDNESDAY NIGHT OR THURSDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
RAIN WILL CONTINUE TO IMPACT THE TERMINALS THROUGH THE MAJORITY OF
THE AFTERNOON IN ADVANCE OF A POTENT COLD FRONT. VFR CEILINGS WILL
PREVAIL FOR ANOTHER FEW HOURS...BEFORE MOISTURE INCREASES AT THE
LOWER LEVELS THIS AFTERNOON AND SUPPORTS 3 TO 6 HOURS OF MVFR
WEATHER. VFR WEATHER WILL RETURN AGAIN TONIGHT. THE POTENTIAL FOR
THUNDER AT EITHER KCHS OR KSAV APPEARS LOWER...CONSIDERING THE
RATHER STABLE AIR MASS IN PLACE UNDER THICK CLOUD COVER AND
WIDESPREAD RAIN. THE BEST TIMING FOR ANY TSRA IS EARLY THIS
AFTERNOON FROM ABOUT 17Z TO 20Z. PERIODIC IFR CONDITIONS COULD
OCCUR WITHIN ANY STRONG SHRA OR TSRA. EVEN OUTSIDE OF
CONVECTION...WINDS WILL BE GUSTY...PEAKING AT 20 TO 25 KT AT TIMES
THROUGH THE EARLY AFTERNOON. THE COLD FRONT PASSAGE WILL THEN
ALLOW WINDS TO VEER FROM SOUTHWEST TO WEST AND DIMINISH 5 TO 10
KT. ANY REDUCTION IN WIND SPEEDS LATE AFTERNOON/EARLY EVENING WILL
LIKELY BE TEMPORARY...AS WINDS INCREASE AGAIN TONIGHT ONCE COLDER
AIR SURGES INTO THE REGION AND KEEPS THE LOWER LEVELS WELL MIXED.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TODAY AND TONIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL
DETERIORATE AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN
APPROACHING COLD FRONT. WINDS AND SEAS WILL INCREASE INTO THE
SMALL CRAFT ADVISORY RANGE ACROSS ALL MARINE AREAS BY THIS
AFTERNOON...WHEN SOUTH TO SOUTHWEST WINDS BECOME 20-25 KT
EVERYWHERE. THE COLD FRONT WILL BEGIN TO MOVE INTO THE COASTAL
WATERS IN THE MID AFTERNOON AND PUSH EAST BY THE EVENING.
OVERNIGHT AND BEHIND THE FRONT...HIGH PRESSURE WILL BEGIN TO
BUILD IN AND WINDS WILL TURN MORE NORTH. THIS NORTHERLY SURGE WILL
BRING WINDS INTO THE 25-30 KT RANGE. THERE IS A LOW CHANCE FOR AN
ISOLATED GUST TO GALE FORCE...BUT THE PROBABILITIES ARE LOW ENOUGH
NOT TO ISSUE A GALE WATCH/WARNING FOR NOW. MARINERS ARE ALSO
ADVISED THAT SHOWERS AND POSSIBLY THUNDERSTORMS COULD MOVE INTO
THE LOCAL WATERS THIS AFTERNOON...SOME OF WHICH WILL BE
ACCOMPANIED BY WIND GUSTS UP TO 40 KT...LIGHTNING AND HEAVY RAIN
THAT REDUCES VISIBILITY.

WEDNESDAY THROUGH FRIDAY...A PROLONGED PERIOD WITH SOLID SMALL
CRAFT ADVISORIES IS IN THE OFFING...COURTESY OF AN IMPRESSIVE RIDGE
OF HIGH PRESSURE THAT EXTENDS OVER THE EASTERN SEABOARD. A PACKED
PRESSURE GRADIENT...THE SO-CALLED PINCHING WILL PREVAIL BETWEEN THIS
HUGE HIGH AND A BAROCLINIC ZONE OVER THE ATLANTIC NOT TOO FAR TO THE
EAST AND SE. THIS GENERATES NORTHEASTERLY WINDS OF 20-30 KT ACROSS
THE OPEN ATLANTIC AND 15-20 KT AND FREQUENTLY HIGHER IN CHARLESTON
HARBOR. THIS FAVORABLE FETCH IN TURN KEEPS SEAS ELEVATED...UP TO 8
OR 9 FT ACROSS THE OUTER GA WATERS...AS HIGH AS 6 OR 7 FT WITHIN 20
NM OF THE SHORE AND UP TO 2 FT IN CHARLESTON HARBOR.

FRIDAY NIGHT THROUGH EASTER SUNDAY...A WAVE OF LOW PRESSURE WILL
FORM OVER OR NEAR THE WATERS LATE IN THE WEEK...BEFORE IT PULLS AWAY
AND ALLOWS FOR CONTINENTAL HIGH PRESSURE TO BUILD BACK IN LATER
SATURDAY AND SUNDAY. WIND AND SEA CONDITIONS WON/T BE QUITE AS HARSH
AS EARLIER IN THE WEEK...BUT WE COULD STILL FLIRT WITH SMALL CRAFT
ADVISORIES ACROSS AT LEAST AMZ374.

RIP CURRENTS...STRONG SOUTHWEST WINDS AND THE FULL MOON SUPPORTS A
HIGH RISK FOR SC BEACHES AND A MODERATE RISK FOR GA BEACHES TODAY.
AN ENHANCED RISK OF RIP CURRENTS WILL PERSIST THROUGH LATE
WEEK...THE RESULT OF ELEVATED SURF AND MODERATE TO STRONG
NORTHEAST WINDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...WIND ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR SCZ044-045-050-
     052.
     HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR
     SCZ048>051.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO NOON EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

NEAR TERM...WMS
SHORT TERM...
LONG TERM...
AVIATION...WMS/
MARINE...WMS/








000
FXUS62 KCHS 151138
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
738 AM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION TODAY. UNSEASONABLY
COOL HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH
THURSDAY. A WAVE OF LOW PRESSURE COULD IMPACT THE AREA AS IT PASSES
NORTHEAST ACROSS THE NEARBY ATLANTIC LATE IN THE WEEK...BEFORE HIGH
PRESSURE RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...A INCREASINGLY ACTIVE DAY IS ON TAP AS A COLD FRONT
APPROACHES THE REGION AND MOVES THROUGH. AS WITH ANY STRONGLY FORCED
SYSTEM DURING THIS TIME OF YEAR...SEVERAL FORECAST PARAMETERS ARE
HIGHLY DEPENDENT ON THE EXACT EVOLUTION AND TIMING OF THE FRONT AND
ASSOCIATED CONVECTION. THE MAIN DRIVER IS A SHARP MID/UPPER LEVEL
TROUGH LIFTING THROUGH THE EASTERN CONUS WITH AN IMPRESSIVE
CHANNELED VORT MAX. THIS FEATURE WILL PUSH A WELL DEFINED COLD FRONT
INTO THE WESTERN PORTIONS OF THE FORECAST AREA THIS MORNING...AND
EVENTUALLY OFF THE COAST BY THIS EVENING. PRECIPITATION CHANCES RAMP
UP RAPIDLY THIS MORNING AND ALL LOCATIONS ARE EXPECTED TO SEE
RAINFALL WITH THUNDERSTORMS SO 100 POPS ARE ATTAINED EVERYWHERE AT
ONE POINT OR ANOTHER. THERE ARE A FEW ASPECTS OF THE FORECAST THAT
ARE WORTH DISCUSSING INDEPENDENTLY GIVEN THE COMPLEXITY OF THE
SETUP.

THUNDERSTORMS AND SEVERE WEATHER...CLUSTERS OF THUNDERSTORMS WILL
PRECEDE AND ACCOMPANY THE FRONT AS IT PUSHES IN FROM THE WEST THIS
MORNING. AN IMPRESSIVE LOW LEVEL JET IS NOTED WITH THE SYSTEM AS
850 MB WINDS SURGE INTO THE 40-50 KT RANGE. AS THE MID/UPPER LEVEL
JET INCREASES IN STRENGTH...DEEP LAYER 0-6 KM SHEAR WILL INCREASE
INTO THE 50-55 KT RANGE. FURTHERMORE...0-3 KM SHEAR WILL BE ON THE
ORDER OF 45 KT. WINDS ARE FAIRLY UNIDIRECTIONAL THROUGH THESE TWO
LAYERS WITH NOT MUCH BACKING OF THE LOW LEVEL FLOW NOTED. SHEAR IS
CERTAINLY NOT IN SHORT SUPPLY...AND THE THREAT OF SEVERE WEATHER
AS USUAL HINGES ON THE DEGREE TO WHICH WE ARE ABLE TO DESTABILIZE.
MODELS ARE PRETTY CONSISTENT IN DEPICTING CAPE VALUES IN THE
250-750 J/KG RANGE IMMEDIATELY ALONG AND AHEAD OF THE PROGRESSING
COLD FRONT. GIVEN THE WIDESPREAD CLOUD COVER AHEAD OF THE
FRONT...NOT MUCH IN THE WAY OF DIRECT SURFACE HEATING WILL BE ABLE
TO OCCUR...SO I WOULD LIKELY FAVOR CAPE VALUES BEING MORE TOWARD
THE 250 J/KG RANGE OF WHAT THE MODELS ARE SHOWING. SO THE
THERMODYNAMIC ENVIRONMENT ISN/T OVERWHELMING FOR SURE. FROM A
DYNAMICS PERSPECTIVE...THE MODELS DO SHOW THE FORECAST AREA BEING
ON THE SOUTHERN END OF THE BETTER LOW LEVEL JETTING WHICH IS
FOCUSED TO THE NORTH. ALSO...IT APPEARS THAT THE UPPER TROUGH IS
BEGINNING TO LIFT AND DEAMPLIFY WITH TIME SO THE BEST DYNAMICS MAY
WELL OCCUR JUST TO OUR NORTH AS WELL. SO...IT DOES NOT APPEAR TO
BE A WIDESPREAD SEVERE WEATHER EVENT BY ANY MEANS...BUT THE SLIGHT
RISK DOES STILL EXIST. GIVEN THE NEAR STORM ENVIRONMENT...THE
CONVECTIVE MODE IS EXPECTED TO FAVOR LINEAR SEGMENTS. GIVEN THE
MAGNITUDE OF THE SHEAR DAMAGING WIND GUSTS ARE THE GREATEST SEVERE
THREAT...BUT A COUPLE OF SHORT- LIVED QLCS TORNADOES ARE CERTAINLY
POSSIBLE WITH BROKEN S RADAR SIGNATURES. THE BEST SEVERE THREAT IS
EAST OF I-95 STRETCHING ACROSS A TIME PERIOD OF ROUGHLY 11 AM TO 4
PM.

WINDS OUTSIDE OF THUNDERSTORMS...MODELS CONSISTENTLY SHOW THE
POTENTIAL FOR WIND ADVISORY CRITERIA WINDS ACROSS MAINLY THE
TRI-COUNTY REGION IN THE LATE MORNING/EARLY AFTERNOON HOURS. A LOT
OF THIS DEPENDS ON HOW MUCH THIS AREA WARMS AHEAD OF THE FRONT AND
THE ASSOCIATED MIXING. SOUNDINGS SHOW 35 KT WINDS ONLY ABOUT 1200 FT
OFF THE SURFACE DURING THIS TIME...AND WE SHOULD SUFFICIENTLY MIX TO
THAT LEVEL FOR GUSTS TO BE THAT STRONG. WE HAVE MAINTAINED THE
WIND ADVISORY FOR DORCHESTER/BERKELEY/CHARLESTON COUNTIES...BUT
LOOKING AT RECENT TRENDS ON SATELLITE AND RADAR THIS CHANCE IS
DEFINITELY LOWER THAN IT APPEARED EARLIER THIS MORNING. ONCE THE
ADVISORY COMES DOWN IN THE AFTERNOON...A LAKE WIND ADVISORY WILL
BE NEEDED FOR LAKE MOULTRIE THAT RUNS THROUGH TUESDAY NIGHT.

TEMPERATURES...A TRICKY HIGH TEMPERATURE FORECAST AS AREAS TO THE
WEST WILL LIKELY SEE LITTLE DIURNAL RISE AS THE FRONT MOVES IN...AND
AREAS TO THE EAST HAVE THE POTENTIAL TO GET INTO THE LOW 80S. THE
FORECAST FEATURES A NARROW AREA ALONG AND EAST OF I-95 WITH MID TO
UPPER 70S AND EVEN SOME VALUES AT 80. THEN ONCE THE FRONT AND
ASSOCIATED THUNDERSTORMS MOVE IN...TEMPERATURES WILL BE CONTROLLED
BY PRECIPITATION EFFECTS...AND PLACES OVER WESTERN INTERIOR GA
WON/T BUDGE OUT OF THE MID AND UPPER 60S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE COLD FRONT WILL PUSH OFF THE COAST AND MUCH DRIER AIR
WILL BEGIN TO FILTER IN FROM THE WEST. SKIES SHOULD CLEAR RAPIDLY
THROUGH THE NIGHT AND WILL BE CLEAR BY THE EARLY MORNING HOURS.
STRENGTHENING HIGH PRESSURE WILL BUILD IN AND RIDGE DOWN THE EAST
SIDE OF THE APPALACHIANS. THE TIGHT NORTHEAST PRESSURE GRADIENT WILL
RESULT IN ABNORMALLY STRONG WINDS FOR THE OVERNIGHT WITH FREQUENT
GUSTS TO 30 MPH EXPECTED THROUGH DAYBREAK. A MUCH COLDER AIRMASS
WILL MOVE IN AND LOWS WILL FALL INTO THE UPPER 30S INLAND...RANGING
TO LOW/MID 40S AT THE COAST. THESE COOL TEMPERATURES COMBINED WITH
THE STRONG AND PERSISTENT NORTHEAST WIND WILL MAKE IT QUITE BLUSTERY
AND WIND CHILLS TO AROUND FREEZING ARE EXPECTED.

WEDNESDAY AND THURSDAY...ROBUST AND STRENGTHENING HIGH PRESSURE WILL
COVER THE AREA EAST OF THE APPALACHIANS...AS IT WEDGES INTO THE SE
PART OF THE COUNTRY. FURTHER OFFSHORE IN THE ATLANTIC WE/LL FIND THE
REMNANTS OF THE COLD FRONT...NOW MORE IN THE SHAPE OF A COASTAL
TROUGH. BETWEEN THESE TWO FEATURES WE LOOK FOR A PINCHING OF THE
PRESSURE PATTERN AND A CONSTANT FEED OF COOL AIR FROM THE NORTH AND
NE. THERE IS EVENTUALLY SOME RETURN FLOW FROM OFF THE OCEAN THAT
WILL FIRST GENERATE SOME MARINE INDUCED STRATOCUMULUS LATE WEDNESDAY
NIGHT AND THURSDAY...WITH MAYBE JUST ENOUGH CONVERGENCE TO PRODUCE
A FEW LOW-TOPPED SHOWERS OVER COASTAL SE GA DURING THURSDAY. THE
TIGHTER PACKING OF THE ISOBARS WILL RESULT IN BREEZY CONDITIONS EACH
DAY INLAND...WITH BREEZY TO WINDY WEATHER THROUGH THE PERIOD CLOSER
TO AND ALONG THE COAST. TEMPS WEDNESDAY WILL BE AT THEIR COOLEST
LEVELS IN ABOUT 3 WEEKS...AND DESPITE THE STRONG APRIL SUNSHINE OUR
MAX TEMPS WILL ONLY ACHIEVE THE LOWER OR MIDDLE 60S AT BEST. IT/S
ANOTHER COOL/CHILLY NIGHT WEDNESDAY NIGHT...ALTHOUGH THE MODERATING
PROCESS BEGINS CLOSER TO THE COAST. THURSDAY WON/T BE AS COOL...BUT
GIVEN A LITTLE GREATER CONCENTRATION OF CLOUDINESS SOUTH AND EAST IT
WILL LIMIT HIGHS TO THE UPPER 60S/LOWER 70S...COOLER ALONG THE
IMMEDIATE COAST.

FRIDAY...A SOUTHERN STREAM SHORT WAVE WILL MOVE INTO THE NE GULF OF
MEXICO...AND DEPENDING UPON WHETHER OR NOT IT PHASES WITH THE
NORTHERN JET WILL DETERMINE WHEN/WHERE AND AT WHAT STRENGTH DOES IT
TRIGGER SURFACE CYCLOGENESIS. CLIMATOLOGY SUGGESTS THIS WILL BE
SOMEWHERE NOT FAR TO OUR SOUTH OR SE. EVEN SO...THE PROXIMITY TO
THESE SYSTEMS AND A NEARBY BAROCLINIC ZONE OVER THE ATLANTIC WILL
COMBINE WITH DEEPER MOISTURE AND ISENTROPIC ASCENT TO PRODUCE AT
LEAST A SLIGHT CHANCE/CHANCE OF SHOWERS. ADJUSTMENTS MAY BE REQUIRED
IN FUTURISTIC FORECASTS ONCE IT BECOMES BETTER DEFINED ON EXACTLY
HOW EVERYTHING WILL UNFOLD. WITH CONSIDERABLE CLOUD COVER AND THE
POTENTIAL FOR SOME WET WEATHER TO ARRIVE...IT/LL BE ANOTHER DAY WITH
MAX TEMPS BELOW SEASONAL NORMS.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND GOOD MIXING ACROSS LAKE
MOULTRIE WILL RESULT IN A LAKE WIND ADVISORY CONTINUING DURING THE
DAY WEDNESDAY...PERHAPS EVEN INTO WEDNESDAY NIGHT OR THURSDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
CONVECTION WILL CONTINUE TO SPREAD INTO THE TERMINALS FROM THE SW
THIS MORNING IN ADVANCE OF A POTENT COLD FRONT. WE/LL HAVE A FEW
HOURS OF VFR CEILINGS...BUT EVENTUALLY THE LOWER ATMOSPHERE
MOISTENS ENOUGH WHERE WE LOOK FOR ABOUT 3-6 HOURS OF MVFR WEATHER
DURING THE AFTERNOON. VFR WEATHER WILL RETURN AGAIN TONIGHT.

THE MOST LIKELY TIME FOR ANY TSRA IS FROM ABOUT 16-19Z AT KSAV AND
17-20Z AT KCHS...A FEW OF WHICH COULD PRODUCE STRONG WINDS AND
HEAVY RAINS...AND THE POTENTIAL FOR PERIODIC IFR WEATHER. EVEN
OUTSIDE OF SHRA AND TSRA WINDS WILL BE GUSTY...PEAKING AT 20-30 KT
AT TIMES FROM LATE MORNING THROUGH EARLY AFTERNOON...BEFORE THE
COLD FRONT CAUSES WINDS TO VEER FROM SW TO WEST AND DROPS SOME
5-10 KT. HOWEVER...THIS IS ONLY TEMPORARY AS WINDS LOOK TO
INCREASE AGAIN TONIGHT AS COLDER AIR SURGES IN AND KEEPS THE LOWER
REACHES OF THE ATMOSPHERE WELL MIXED.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TODAY AND TONIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL
DETERIORATE AS THE PRESSURE GRADIENT TIGHTENS UP AHEAD OF AN
APPROACHING COLD FRONT. WINDS AND SEAS WILL INCREASE INTO THE
SMALL CRAFT ADVISORY RANGE WITH ALL MARINE AREAS BEING UNDER AN
ADVISORY BY THE AFTERNOON. NO SIGNIFICANT CHANGES WERE MADE TO THE
FORECAST...AND SOUTH TO SOUTHWEST WINDS WILL BECOME 20-25 KT
EVERYWHERE BY THE AFTERNOON. THE ONE TRICKY SPOT WILL BE THE
CHARLESTON HARBOR LATE THIS MORNING AND INTO THE AFTERNOON HOURS.
LAND AREAS AROUND THE HARBOR ARE EXPECTED TO SEE GUSTS TO 35 KT
FOR A FEW HOURS...BUT GIVEN THE FACT THAT IDEAL MIXING WILL NOT
OCCUR IN THE WARM ADVECTION WINDS IN THE HARBOR WILL REMAIN JUST
BELOW GALE FORCE. THE COLD FRONT WILL BEGIN TO MOVE INTO THE
COASTAL WATERS IN THE MID AFTERNOON AND WILL PUSH OFF TO THE EAST
BY THE EVENING. OVERNIGHT BEHIND THE FRONT...HIGH PRESSURE WILL
BEGIN TO BUILD IN AND WINDS WILL TURN MORE N. THIS NORTHERLY SURGE
WILL BRING WINDS INTO THE 25-30 KT RANGE. THERE IS A LOW CHANCE
FOR AN ISOLATED GUST TO GALE FORCE...BUT THE PROBABILITIES ARE LOW
ENOUGH TO NOT GO WITH A GALE WATCH/WARNING FOR NOW. MARINERS ARE
ALSO ADVISED THAT STRONG T-STORMS WILL MOVE INTO THE LOCAL WATERS
LATE THIS MORNING AND AFTERNOON...SOME OF WHICH WILL BE
ACCOMPANIED BY WIND GUSTS PAST 40 KT...FREQUENT LIGHTNING AND
HEAVY RAINS DROPPING VISIBILITY.

WEDNESDAY THROUGH FRIDAY...A PROLONGED PERIOD WITH SOLID SMALL
CRAFT ADVISORIES IS IN THE OFFING...COURTESY OF AN IMPRESSIVE RIDGE
OF HIGH PRESSURE THAT EXTENDS OVER THE EASTERN SEABOARD. A PACKED
PRESSURE GRADIENT...THE SO-CALLED PINCHING WILL PREVAIL BETWEEN THIS
HUGE HIGH AND A BAROCLINIC ZONE OVER THE ATLANTIC NOT TOO FAR TO THE
EAST AND SE. THIS GENERATES NORTHEASTERLY WINDS OF 20-30 KT ACROSS
THE OPEN ATLANTIC AND 15-20 KT AND FREQUENTLY HIGHER IN CHARLESTON
HARBOR. THIS FAVORABLE FETCH IN TURN KEEPS SEAS ELEVATED...UP TO 8
OR 9 FT ACROSS THE OUTER GA WATERS...AS HIGH AS 6 OR 7 FT WITHIN 20
NM OF THE SHORE AND UP TO 2 FT IN CHARLESTON HARBOR.

FRIDAY NIGHT THROUGH EASTER SUNDAY...A WAVE OF LOW PRESSURE WILL
FORM OVER OR NEAR THE WATERS LATE IN THE WEEK...BEFORE IT PULLS AWAY
AND ALLOWS FOR CONTINENTAL HIGH PRESSURE TO BUILD BACK IN LATER
SATURDAY AND SUNDAY. WIND AND SEA CONDITIONS WON/T BE QUITE AS HARSH
AS EARLIER IN THE WEEK...BUT WE COULD STILL FLIRT WITH SMALL CRAFT
ADVISORIES ACROSS AT LEAST AMZ374.

RIP CURRENTS...STRONG SOUTHWEST WINDS AND THE FULL MOON RESULT IN
A HIGH RISK FOR SC BEACHES AND A MODERATE RISK FOR GA BEACHES
TODAY. AN ENHANCED RISK OF RIP CURRENTS WILL PERSIST THROUGH LATE
WEEK...THE RESULT OF ELEVATED SURF AND MODERATE TO STRONG NE
WINDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...WIND ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR SCZ044-045-050-
     052.
     HIGH RISK FOR RIP CURRENTS THROUGH THIS EVENING FOR SCZ048>051.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO NOON EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THURSDAY FOR AMZ330.

&&

$$

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








000
FXUS62 KCHS 150803
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
403 AM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION TODAY. UNSEASONABLY
COOL HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH
THURSDAY. A WAVE OF LOW PRESSURE COULD IMPACT THE AREA AS IT PASSES
NORTHEAST ACROSS THE NEARBY ATLANTIC LATE IN THE WEEK...BEFORE HIGH
PRESSURE RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...A INCREASINGLY ACTIVE DAY IS ON TAP AS A COLD FRONT
APPROACHES THE REGION AND MOVES THROUGH. AS WITH ANY STRONGLY FORCED
SYSTEM DURING THIS TIME OF YEAR...SEVERAL FORECAST PARAMETERS ARE
HIGHLY DEPENDENT ON THE EXACT EVOLUTION AND TIMING OF THE FRONT AND
ASSOCIATED CONVECTION. THE MAIN DRIVER IS A SHARP MID/UPPER LEVEL
TROUGH LIFTING THROUGH THE EASTERN CONUS WITH AN IMPRESSIVE
CHANNELED VORT MAX. THIS FEATURE WILL PUSH A WELL DEFINED COLD FRONT
INTO THE WESTERN PORTIONS OF THE FORECAST AREA THIS MORNING...AND
EVENTUALLY OFF THE COAST BY THIS EVENING. PRECIPITATION CHANCES RAMP
UP RAPIDLY THIS MORNING AND ALL LOCATIONS ARE EXPECTED TO SEE
RAINFALL WITH THUNDERSTORMS SO 100 POPS ARE ATTAINED EVERYWHERE AT
ONE POINT OR ANOTHER. THERE ARE A FEW ASPECTS OF THE FORECAST THAT
ARE WORTH DISCUSSING INDEPENDENTLY GIVEN THE COMPLEXITY OF THE
SETUP.

THUNDERSTORMS AND SEVERE WEATHER...A LINE OF THUNDERSTORMS IS
EXPECTED TO ACCOMPANY THE FRONT AS IT PUSHES IN FROM THE WEST THIS
MORNING. AN IMPRESSIVE LOW LEVEL JET IS NOTED WITH THE SYSTEM AS 850
MB WINDS SURGE INTO THE 40-50 KT RANGE. AS THE MID/UPPER LEVEL JET
INCREASES IN STRENGTH...DEEP LAYER 0-6 KM SHEAR WILL INCREASE INTO
THE 50-55 KT RANGE. FURTHERMORE...0-3 KM SHEAR WILL BE ON THE ORDER
OF 45 KT. WINDS ARE FAIRLY UNIDIRECTIONAL THROUGH THESE TWO LAYERS
WITH NOT MUCH BACKING OF THE LOW LEVEL FLOW NOTED. SHEAR IS
CERTAINLY NOT IN SHORT SUPPLY...AND THE THREAT OF SEVERE WEATHER AS
USUAL HINGES ON THE DEGREE TO WHICH WE ARE ABLE TO DESTABILIZE.
MODELS ARE PRETTY CONSISTENT IN DEPICTING CAPE VALUES IN THE 250-750
J/KG RANGE IMMEDIATELY ALONG AND AHEAD OF THE PROGRESSING COLD
FRONT. GIVEN THE WIDESPREAD CLOUD COVER AHEAD OF THE FRONT...NOT
MUCH IN THE WAY OF DIRECT SURFACE HEATING WILL BE ABLE TO OCCUR...SO
I WOULD LIKELY FAVOR CAPE VALUES BEING MORE TOWARD THE 250 J/KG
RANGE OF WHAT THE MODELS ARE SHOWING. SO THE THERMODYNAMIC
ENVIRONMENT ISN/T OVERWHELMING FOR SURE. FROM A DYNAMICS
PERSPECTIVE...THE MODELS DO SHOW THE FORECAST AREA BEING ON THE
SOUTHERN END OF THE BETTER LOW LEVEL JETTING WHICH IS FOCUSED TO THE
NORTH. ALSO...IT APPEARS THAT THE UPPER TROUGH IS BEGINNING TO LIFT
AND DEAMPLIFY WITH TIME SO THE BEST DYNAMICS MAY WELL OCCUR JUST TO
OUR NORTH AS WELL. SO...ITS HARD TO SAY WITH MUCH CONFIDENCE THAT
THIS WILL BE A WIDESPREAD SEVERE WEATHER EVENT...BUT I ALSO CANNOT
RULE IT OUT EITHER. GIVEN THE NEAR STORM ENVIRONMENT...THE
CONVECTIVE MODE IS EXPECTED TO FAVOR LINEAR SEGMENTS. GIVEN THE
MAGNITUDE OF THE SHEAR DAMAGING WIND GUSTS ARE THE GREATEST SEVERE
THREAT...BUT A COUPLE OF SHORT-LIVED QLCS TORNADOES ARE CERTAINLY
POSSIBLE WITH BROKEN S RADAR SIGNATURES. THE BEST SEVERE THREAT MAY
END UP BEING EAST OF I-95 STRETCHING ACROSS A TIME PERIOD OF ROUGHLY
9 AM TO 4 PM.

WINDS OUTSIDE OF THUNDERSTORMS...MODELS CONSISTENTLY SHOW THE
POTENTIAL FOR WIND ADVISORY CRITERIA WINDS ACROSS MAINLY THE
TRI-COUNTY REGION IN THE LATE MORNING/EARLY AFTERNOON HOURS. A LOT
OF THIS DEPENDS ON HOW MUCH THIS AREA WARMS AHEAD OF THE FRONT AND
THE ASSOCIATED MIXING. SOUNDINGS SHOW 35 KT WINDS ONLY ABOUT 1200 FT
OFF THE SURFACE DURING THIS TIME...AND WE SHOULD SUFFICIENTLY MIX TO
THAT LEVEL FOR GUSTS TO BE THAT STRONG. THEREFORE...WILL HOIST A
WIND ADVISORY FOR DORCHESTER/BERKELEY/CHARLESTON COUNTIES. ONCE
THE ADVISORY COMES DOWN IN THE AFTERNOON...A LAKE WIND ADVISORY
WILL BE NEEDED FOR LAKE MOULTRIE THAT RUNS THROUGH TUESDAY NIGHT.

TEMPERATURES...A TRICKY HIGH TEMPERATURE FORECAST AS AREAS TO THE
WEST WILL LIKELY SEE LITTLE DIURNAL RISE AS THE FRONT MOVES IN...AND
AREAS TO THE EAST HAVE THE POTENTIAL TO GET INTO THE LOW 80S. THE
FORECAST FEATURES A NARROW AREA ALONG AND EAST OF I-95 WITH MID TO
UPPER 70S AND EVEN SOME VALUES AT 80. THEN ONCE THE FRONT AND
ASSOCIATED THUNDERSTORMS MOVE IN...TEMPERATURES WILL BE CONTROLLED
BY PRECIPITATION EFFECTS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE COLD FRONT WILL PUSH OFF THE COAST AND MUCH DRIER AIR
WILL BEGIN TO FILTER IN FROM THE WEST. SKIES SHOULD CLEAR RAPIDLY
THROUGH THE NIGHT AND WILL BE CLEAR BY THE EARLY MORNING HOURS.
STRENGTHENING HIGH PRESSURE WILL BUILD IN AND RIDGE DOWN THE EAST
SIDE OF THE APPALACHIANS. THE TIGHT NORTHEAST PRESSURE GRADIENT WILL
RESULT IN ABNORMALLY STRONG WINDS FOR THE OVERNIGHT WITH FREQUENT
GUSTS TO 30 MPH EXPECTED THROUGH DAYBREAK. A MUCH COLDER AIRMASS
WILL MOVE IN AND LOWS WILL FALL INTO THE UPPER 30S INLAND...RANGING
TO LOW/MID 40S AT THE COAST. THESE COOL TEMPERATURES COMBINED WITH
THE STRONG AND PERSISTENT NORTHEAST WIND WILL MAKE IT QUITE BLUSTERY
AND WIND CHILLS TO AROUND FREEZING ARE EXPECTED.

WEDNESDAY AND THURSDAY...ROBUST AND STRENGTHENING HIGH PRESSURE WILL
COVER THE AREA EAST OF THE APPALACHIANS...AS IT WEDGES INTO THE SE
PART OF THE COUNTRY. FURTHER OFFSHORE IN THE ATLANTIC WE/LL FIND THE
REMNANTS OF THE COLD FRONT...NOW MORE IN THE SHAPE OF A COASTAL
TROUGH. BETWEEN THESE TWO FEATURES WE LOOK FOR A PINCHING OF THE
PRESSURE PATTERN AND A CONSTANT FEED OF COOL AIR FROM THE NORTH AND
NE. THERE IS EVENTUALLY SOME RETURN FLOW FROM OFF THE OCEAN THAT
WILL FIRST GENERATE SOME MARINE INDUCED STRATOCUMULUS LATE WEDNESDAY
NIGHT AND THURSDAY...WITH MAYBE JUST ENOUGH CONVERGENCE TO PRODUCE
A FEW LOW-TOPPED SHOWERS OVER COASTAL SE GA DURING THURSDAY. THE
TIGHTER PACKING OF THE ISOBARS WILL RESULT IN BREEZY CONDITIONS EACH
DAY INLAND...WITH BREEZY TO WINDY WEATHER THROUGH THE PERIOD CLOSER
TO AND ALONG THE COAST. TEMPS WEDNESDAY WILL BE AT THEIR COOLEST
LEVELS IN ABOUT 3 WEEKS...AND DESPITE THE STRONG APRIL SUNSHINE OUR
MAX TEMPS WILL ONLY ACHIEVE THE LOWER OR MIDDLE 60S AT BEST. IT/S
ANOTHER COOL/CHILLY NIGHT WEDNESDAY NIGHT...ALTHOUGH THE MODERATING
PROCESS BEGINS CLOSER TO THE COAST. THURSDAY WON/T BE AS COOL...BUT
GIVEN A LITTLE GREATER CONCENTRATION OF CLOUDINESS SOUTH AND EAST IT
WILL LIMIT HIGHS TO THE UPPER 60S/LOWER 70S...COOLER ALONG THE
IMMEDIATE COAST.

FRIDAY...A SOUTHERN STREAM SHORT WAVE WILL MOVE INTO THE NE GULF OF
MEXICO...AND DEPENDING UPON WHETHER OR NOT IT PHASES WITH THE
NORTHERN JET WILL DETERMINE WHEN/WHERE AND AT WHAT STRENGTH DOES IT
TRIGGER SURFACE CYCLOGENESIS. CLIMATOLOGY SUGGESTS THIS WILL BE
SOMEWHERE NOT FAR TO OUR SOUTH OR SE. EVEN SO...THE PROXIMITY TO
THESE SYSTEMS AND A NEARBY BAROCLINIC ZONE OVER THE ATLANTIC WILL
COMBINE WITH DEEPER MOISTURE AND ISENTROPIC ASCENT TO PRODUCE AT
LEAST A SLIGHT CHANCE/CHANCE OF SHOWERS. ADJUSTMENTS MAY BE REQUIRED
IN FUTURISTIC FORECASTS ONCE IT BECOMES BETTER DEFINED ON EXACTLY
HOW EVERYTHING WILL UNFOLD. WITH CONSIDERABLE CLOUD COVER AND THE
POTENTIAL FOR SOME WET WEATHER TO ARRIVE...IT/LL BE ANOTHER DAY WITH
MAX TEMPS BELOW SEASONAL NORMS.

LAKE WINDS...A TIGHT PRESSURE GRADIENT AND GOOD MIXING ACROSS LAKE
MOULTRIE WILL RESULT IN A LAKE WIND ADVISORY CONTINUING DURING THE
DAY WEDNESDAY...PERHAPS EVEN INTO WEDNESDAY NIGHT OR THURSDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A SURFACE LOW PRESSURE AREA WILL LIFT NE ACROSS THE NEARBY ATLANTIC
WATERS LATE IN THE WEEK...BEFORE SHIFTING FURTHER EAST OF NE AND
AWAY FROM THE AREA BEFORE EASTER MORN. HIGH PRESSURE THEN RETURNS
FOR EARLY NEXT WEEK. WE ANTICIPATE AT LEAST SOME WET WEATHER IN
ASSOCIATION WITH THE LOW AND ITS CO-LOCATED SHORT WAVE IMPULSE ALOFT
FRIDAY NIGHT INTO EARLY SATURDAY. AND THERE IS PROBABLY A SHARP
GRADIENT OF RAINFALL...WITH HIGHEST COVERAGE SOUTHEAST AND LESS
PROBABILITIES NORTHWEST. DRIER CONDITIONS WILL THEN PREVAIL LATER
SATURDAY...EASTER DAY AND MONDAY...BEFORE SOME MOISTURE RETURN
COULD TRIGGER A FEW SHOWERS NEXT TUESDAY. NO EXTREMES IN TEMPS ARE
EXPECTED THROUGH THE EXTENDED PERIODS.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THE PRIMARY NEAR TERM CONCERN IS THE POTENTIAL FOR TEMPO MVFR
CONDITIONS AT KCHS WITH PASSING SHOWERS OVER THE NEXT COUPLE OF
HOURS. OVERALL I ANTICIPATE BOTH SITES BEING PREVAILING VFR...BUT
BRIEF REDUCTIONS IN CEILINGS TO MVFR CANNOT BE RULED OUT. THEN
AFTER SUNRISE CONDITIONS WILL BECOME MUCH MORE ACTIVE AS A STRONG
COLD FRONT BEGINS TO IMPACT THE REGION. THE FRONT IS EXPECTED TO
BRING A LINE OF THUNDERSTORMS INTO BOTH SITES...AND I HAVE
ADJUSTED TO TIMING OF TSRA EARLIER THAN THE PREVIOUS FORECAST.
THIS INTRODUCES THUNDER AT 17Z AT KSAV AND 18Z AT KCHS. FOR NOW I
HAVE GONE WITH MVFR CONDITIONS WITH THE THUNDER...BUT THERE IS THE
POTENTIAL FOR BRIEF IFR REDUCTIONS IN VISIBILITY AS THE LINE OF
STORMS PASSES. BUT WILL LET FUTURE FORECASTS NAIL DOWN THE
LIKELIHOOD OF IFR DURING THAT TIME. THUNDERSTORMS SHOULD BE
RELATIVELY SHORT-LIVED AT BOTH SITES...FOR AN HOUR OR TWO...AND
THEN FOLLOWED BY A PERIOD OF LIGHTER SHOWERS OR STRATIFORM RAIN.
CONDITIONS WILL THEN CLEAR OUT THIS EVENING WITH SKC EXPECTED LATE
IN THE FORECAST PERIOD. WINDS WILL ALSO BE A CONCERN...ESPECIALLY
AT KCHS AS SOUTHWEST FLOW BECOMES QUITE GUSTY. THERE IS A NARROW
TIME WINDOW AROUND 17Z WHERE KCHS COULD GUST TO NEAR 35 KT. GUSTS
AT KSAV ARE NOT EXPECTED TO BE QUITE THIS STRONG AS THE LOW LEVEL
JET WILL BE WEAKER THERE.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER IS POSSIBLE LATE
WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM
OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE FRIDAY NIGHT INTO
EARLY SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND
PASSES NEARBY ACROSS THE ADJACENT ATLANTIC.

&&

.MARINE...
TODAY AND TONIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL
DETERIORATE AS THE PRESSURE GRADIENT TIGHTENS UP AHEAD OF AN
APPROACHING COLD FRONT. WINDS AND SEAS WILL INCREASE INTO THE
SMALL CRAFT ADVISORY RANGE WITH ALL MARINE AREAS BEING UNDER AN
ADVISORY BY THE AFTERNOON. NO SIGNIFICANT CHANGES WERE MADE TO THE
FORECAST...AND SOUTH TO SOUTHWEST WINDS WILL BECOME 20-25 KT
EVERYWHERE BY THE AFTERNOON. THE ONE TRICKY SPOT WILL BE THE
CHARLESTON HARBOR LATE THIS MORNING AND INTO THE AFTERNOON HOURS.
LAND AREAS AROUND THE HARBOR ARE EXPECTED TO SEE GUSTS TO 35 KT
FOR A FEW HOURS...BUT GIVEN THE FACT THAT IDEAL MIXING WILL NOT
OCCUR IN THE WARM ADVECTION WINDS IN THE HARBOR WILL REMAIN JUST
BELOW GALE FORCE. THE COLD FRONT WILL BEGIN TO MOVE INTO THE
COASTAL WATERS IN THE MID AFTERNOON AND WILL PUSH OFF TO THE EAST
BY THE EVENING. OVERNIGHT BEHIND THE FRONT...HIGH PRESSURE WILL
BEGIN TO BUILD IN AND WINDS WILL TURN MORE N. THIS NORTHERLY SURGE
WILL BRING WINDS INTO THE 25-30 KT RANGE. THERE IS A LOW CHANCE
FOR AN ISOLATED GUST TO GALE FORCE...BUT THE PROBABILITIES ARE LOW
ENOUGH TO NOT GO WITH A GALE WATCH/WARNING FOR NOW.

WEDNESDAY THROUGH FRIDAY...A PROLONGED PERIOD WITH SOLID SMALL
CRAFT ADVISORIES IS IN THE OFFING...COURTESY OF AN IMPRESSIVE RIDGE
OF HIGH PRESSURE THAT EXTENDS OVER THE EASTERN SEABOARD. A PACKED
PRESSURE GRADIENT...THE SO-CALLED PINCHING WILL PREVAIL BETWEEN THIS
HUGE HIGH AND A BAROCLINIC ZONE OVER THE ATLANTIC NOT TOO FAR TO THE
EAST AND SE. THIS GENERATES NORTHEASTERLY WINDS OF 20-30 KT ACROSS
THE OPEN ATLANTIC AND 15-20 KT AND FREQUENTLY HIGHER IN CHARLESTON
HARBOR. THIS FAVORABLE FETCH IN TURN KEEPS SEAS ELEVATED...UP TO 8
OR 9 FT ACROSS THE OUTER GA WATERS...AS HIGH AS 6 OR 7 FT WITHIN 20
NM OF THE SHORE AND UP TO 2 FT IN CHARLESTON HARBOR.

FRIDAY NIGHT THROUGH EASTER SUNDAY...A WAVE OF LOW PRESSURE WILL
FORM OVER OR NEAR THE WATERS LATE IN THE WEEK...BEFORE IT PULLS AWAY
AND ALLOWS FOR CONTINENTAL HIGH PRESSURE TO BUILD BACK IN LATER
SATURDAY AND SUNDAY. WIND AND SEA CONDITIONS WON/T BE QUITE AS HARSH
AS EARLIER IN THE WEEK...BUT WE COULD STILL FLIRT WITH SMALL CRAFT
ADVISORIES ACROSS AT LEAST AMZ374.

RIP CURRENTS...STRONG SOUTHWEST WINDS AND THE FULL MOON RESULT IN
A HIGH RISK FOR SC BEACHES AND A MODERATE RISK FOR GA BEACHES
TODAY. AN ENHANCED RISK OF RIP CURRENTS WILL PERSIST THROUGH LATE
WEEK...THE RESULT OF ELEVATED SURF AND MODERATE TO STRONG NE
WINDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...WIND ADVISORY FROM 10 AM THIS MORNING TO 5 PM EDT THIS
     AFTERNOON FOR SCZ044-045-050-052.
     HIGH RISK FOR RIP CURRENTS FROM 8 AM EDT THIS MORNING THROUGH
     THIS EVENING FOR SCZ048>051.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO NOON EDT
     SATURDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO NOON EDT
     SATURDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 5 PM EDT
     THURSDAY FOR AMZ330.

&&

$$

SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...33
LONG TERM...33
AVIATION...BSH
MARINE...BSH/33






000
FXUS62 KCHS 150614
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
214 AM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH THE AREA FROM THE WEST EARLY
TUESDAY...POSSIBLY ACCOMPANIED BY SEVERE THUNDERSTORMS...THEN PUSH
OFFSHORE LATER IN THE AFTERNOON. UNSEASONABLY COOL HIGH PRESSURE
WILL FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH THURSDAY. A WAVE
OF LOW PRESSURE COULD SKIRT THE AREA FROM OUT OF THE GULF LATE IN
THE WEEK...BEFORE HIGH PRESSURE RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
EARLY THIS MORNING...WARM AND MOIST SOUTHERLY FLOW CONTINUES
ACROSS THE REGION AND WE ARE NOW SEEING SOME SHOWERS FROM THE
COASTAL WATERS START TO PUSH ONSHORE ALONG THE CHARLESTON COUNTY
COAST. I HAVE ADJUSTED POPS TO MATCH CURRENT RADAR TRENDS AND THEN
POPS RAMP UP THROUGH THE MORNING AS PRECIPITATION CHANCES INCREASE
WITH THE APPROACHING COLD FRONT. TEMPERATURES WILL REMAIN QUITE
WARM THROUGH THE NIGHT...WITH MANY AREAS NOT FALLING OUT OF THE
LOW 70S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY...VERY ACTIVE DAY AS A STRONG COLD FRONT APPROACHES FROM THE
WEST EARLY IN THE MORNING...THEN PUSHES OFFSHORE LATER IN THE
AFTERNOON. AHEAD OF THE FRONT UNSEASONABLY MOIST AND POSSIBLY WARM
AIR WILL MOVE INTO THE AREA. VERY STRONG WIND FIELDS WILL BE IN
PLACE AS LOW PRESSURE INTENSIFIES ALONG THE FRONT. AS USUAL FOR THIS
TIME OF YEAR...INSTABILITY IS THE BIGGEST QUESTION...BUT THERE
SHOULD BE ENOUGH IN THE LOWER LEVELS TO AT LEAST YIELD SOME STRONGER
STORMS AS TEMPS PUSH INTO THE MID TO UPPER 70S. SOME GUIDANCE
INDICATES LOWER TO MID 80S AROUND CHARLESTON...AND IF THIS WERE
TO BE THE CASE...INSTABILITY WILL BE PLENTY SUFFICIENT FOR SEVERE
STORMS. ALTHOUGH DAMAGING WINDS WILL BE THE MAIN HAZARD...LOW-LEVEL
HELICITY VALUES LOOK HIGH ENOUGH TO WARRANT AT LEAST A LOW END
TORNADO RISK AS WELL. EVEN OUTSIDE ANY STORMS...THE PRESSURE
GRADIENT WILL BE STRONG ENOUGH TO MAKE FOR A BREEZY TO POTENTIALLY
WINDY DAY...WITH THE STRONGEST WINDS MOST LIKELY ALONG THE SC
COAST UP INTO THE CHARLESTON METRO AREA. A WIND ADVISORY MAY
EVENTUALLY BE NEEDED...AND AT THE VERY LEAST A WIND ADVISORY FOR
LAKE MOULTRIE. THE FRONT SHOULD PUSH INTO THE ATLANTIC LATER IN
THE AFTERNOON WITH RAIN CHANCES QUICKLY ENDING THEREAFTER AS MUCH
DRIER AIR FILTERS IN FROM THE WEST. TEMPS BY DAYBREAK WEDNESDAY
WILL BE AROUND 40 INLAND WITH LOWER TO MID 40S AT THE COAST.

WEDNESDAY...DRY AND BREEZY WITH TEMPS WELL BELOW NORMAL AS COOL HIGH
PRESSURE BUILDS FROM THE NORTH. ANY ATLANTIC SHOWERS SHOULD REMAIN
OFFSHORE. HIGHS LIKELY NEAR 60 NORTH WITH MID 60S SOUTH. ANOTHER
CHILLY NIGHT WEDNESDAY NIGHT WITH TEMPS LIKELY INTO THE UPPER 30S
WELL INLAND AND MID/UPPER 40S ALONG THE SC COAST AND LOWER 50S ALONG
THE GA COAST.

THURSDAY...PRETTY MUCH A CARBON COPY OF WEDNESDAY EXCEPT A LITTLE
WARMER.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR LATE IN THE WEEK INTO EASTER WEEKEND IS A FAIRLY
LOW CONFIDENCE FORECAST IN REGARDS TO EXACT DETAILS. HOWEVER...THE
MID WEEK WEDGE OF HIGH PRESSURE EVENTUALLY STARTS TO ERODE ON
FRIDAY...AS A TROUGH OF LOW PRESSURE FORMS OVER THE SW ATLANTIC AND
WAVES OF LOW PRESSURE DEVELOP ALONG THE PRE-EXISTING BAROCLINIC ZONE
OVER THE OCEAN AND/OR A MORE PRONOUNCED LOW ARRIVES FROM OUT OF THE
GULF OF MEXICO FOR SATURDAY. DRIER HIGH PRESSURE EITHER WAY LOOKS TO
BUILD BACK IN FOR EASTER DAY AND NEXT MONDAY AS WELL. TEMPS LOOK TO
BE NEAR OR SLIGHTLY ABOVE CLIMATOLOGY THROUGH THE PERIOD. AT LEAST
SOME RAIN CHANCE IS EVIDENT THROUGH SATURDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THE PRIMARY NEAR TERM CONCERN IS THE POTENTIAL FOR TEMPO MVFR
CONDITIONS AT KCHS WITH PASSING SHOWERS OVER THE NEXT COUPLE OF
HOURS. OVERALL I ANTICIPATE BOTH SITES BEING PREVAILING VFR...BUT
BRIEF REDUCTIONS IN CEILINGS TO MVFR CANNOT BE RULED OUT. THEN
AFTER SUNRISE CONDITIONS WILL BECOME MUCH MORE ACTIVE AS A STRONG
COLD FRONT BEGINS TO IMPACT THE REGION. THE FRONT IS EXPECTED TO
BRING A LINE OF THUNDERSTORMS INTO BOTH SITES...AND I HAVE
ADJUSTED TO TIMING OF TSRA EARLIER THAN THE PREVIOUS FORECAST.
THIS INTRODUCES THUNDER AT 17Z AT KSAV AND 18Z AT KCHS. FOR NOW I
HAVE GONE WITH MVFR CONDITIONS WITH THE THUNDER...BUT THERE IS THE
POTENTIAL FOR BRIEF IFR REDUCTIONS IN VISIBILITY AS THE LINE OF
STORMS PASSES. BUT WILL LET FUTURE FORECASTS NAIL DOWN THE
LIKELIHOOD OF IFR DURING THAT TIME. THUNDERSTORMS SHOULD BE
RELATIVELY SHORT-LIVED AT BOTH SITES...FOR AN HOUR OR TWO...AND
THEN FOLLOWED BY A PERIOD OF LIGHTER SHOWERS OR STRATIFORM RAIN.
CONDITIONS WILL THEN CLEAR OUT THIS EVENING WITH SKC EXPECTED LATE
IN THE FORECAST PERIOD. WINDS WILL ALSO BE A CONCERN...ESPECIALLY
AT KCHS AS SOUTHWEST FLOW BECOMES QUITE GUSTY. THERE IS A NARROW
TIME WINDOW AROUND 17Z WHERE KCHS COULD GUST TO NEAR 35 KT. GUSTS
AT KSAV ARE NOT EXPECTED TO BE QUITE THIS STRONG AS THE LOW LEVEL
JET WILL BE WEAKER THERE.

EXTENDED AVIATION OUTLOOK...WIND GUSTS WILL CONTINUE AND BE THE
DOMINANT IMPACT INTO LATE WEEK. SUB-VFR WEATHER AGAIN POSSIBLE
LATE WEDNESDAY NIGHT OR THURSDAY THROUGH FRIDAY AS MOISTURE
RETURNS FROM OFF THE ATLANTIC...THEN POSSIBLY A BETTER CHANCE INTO
SATURDAY AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND OVER
THE AREA OR JUST OFFSHORE.

&&

.MARINE...
TONIGHT...SEAS AT 41004 AND 41008 ARE RUNNING ABOUT 1-2 FT HIGHER
THAN THE LATEST WW4 RUN. ASSUMING THIS TREND CONTINUES AS WINDS
INCREASE TO 15 KT NEARSHORE...15-20 KT OFFSHORE...SEAS WILL REACH
SMALL CRAFT ADVISORY THRESHOLDS A LITTLE EARLIER THAN PREVIOUSLY
THOUGHT. ADJUSTED THE START TIME OF THE VARIOUS ADVISORIES GIVEN
THIS.

TUESDAY THROUGH SATURDAY...A COLD FRONT APPROACHING FROM THE WEST
TUESDAY WILL KEEP A STRONG PRESSURE GRADIENT IN PLACE OVER THE LOCAL
WATERS AND ADVISORIES ARE EXPECTED FOR ALL WATERS. THERE IS THE
POTENTIAL THAT WINDS COULD GUST NEAR GALE FORCE...ESPECIALLY ACROSS
FAR INLAND PORTIONS OF CHARLESTON HARBOR WHERE BETTER MIXING IS
EXPECTED OVER LAND AREAS DURING THE AFTERNOON UNTIL THE FRONT PASSES
LATER IN THE AFTERNOON. OTHERWISE...THE STRONG GRADIENT WILL REMAIN
IN PLACE THROUGH MID WEEK AS COOL HIGH PRESSURE BUILDS FROM THE
NORTH AND THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO
FRIDAY...ALTHOUGH POSSIBLY ENDING THURSDAY IN CHARLESTON HARBOR.

RIP CURRENTS...STRONG SOUTH TO SOUTHWEST WINDS AHEAD OF AN
APPROACHING COLD FRONT WILL COMBINE WITH ASTRONOMICAL INFLUENCES
FROM THE FULL MOON TO RESULT IN AN ENHANCED RISK FOR RIP CURRENTS ON
TUESDAY. LOOKS LIKE A HIGH RISK ALONG THE SC COAST AND A MODERATE
RISK ALONG THE GA COAST. BEHIND THE FRONT BEGINNING WEDNESDAY...STRONG
NORTH/NORTHEAST WINDS ARE EXPECTED THROUGH AT LEAST FRIDAY. AS
SUCH...THE ENHANCED RISK FOR RIP CURRENTS WILL CONTINUE THROUGH THE
REMAINDER OF THE WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...HIGH RISK FOR RIP CURRENTS FROM 8 AM EDT THIS MORNING THROUGH
     THIS EVENING FOR SCZ048>051.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 PM EDT
     FRIDAY FOR AMZ352.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT FRIDAY FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 5 PM EDT
     FRIDAY FOR AMZ354.
     SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 PM EDT
     THURSDAY FOR AMZ330.

&&

$$

SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...RJB
LONG TERM...33
AVIATION...BSH
MARINE...RJB/ST






000
FXUS62 KCHS 150317
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1117 PM EDT MON APR 14 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH THE AREA FROM THE WEST EARLY
TUESDAY...POSSIBLY ACCOMPANIED BY SEVERE THUNDERSTORMS...THEN PUSH
OFFSHORE LATER IN THE AFTERNOON. UNSEASONABLY COOL HIGH PRESSURE
WILL FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH THURSDAY. A WAVE
OF LOW PRESSURE COULD SKIRT THE AREA FROM OUT OF THE GULF LATE IN
THE WEEK...BEFORE HIGH PRESSURE RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A WELL-DEFINED OUTFLOW BOUNDARY IS BECOMING INCREASINGLY MORE
DEFINED ACROSS CENTRAL GEORGIA THIS EVENING PER KJGX REFLECTIVITY
DATA. SHOWERS/TSTMS HAVE BEEN SLOWLY INCREASING IN COVERAGE
ACROSS CENTRAL GEORGIA...THE CSRA...THE WESTERN MIDLANDS AND MORE
RECENTLY FAR INTERIOR SOUTHEAST GEORGIA IN RESPONSE TO A
STRENGTHENING NOCTURNAL LOW-LEVEL JET. GUIDANCE IS STILL SHOWING A
SPREAD IN THE COVERAGE OF SHOWER/TSTM ACTIVITY THAT WILL AFFECT
THE AREA OVERNIGHT...BUT RECENT RADAR TRENDS SUGGEST AN INCREASE
IN POPS TO 50 PERCENT IS WARRANTED FOR OVER THE FAR WESTERN ZONES
FROM ROUGHLY ALLENDALE TO REIDSVILLE AND POINTS WEST. THE H3R
STILL DEPICTS A LINE OF SHOWERS/TSTMS APPROACHING THE FAR
INTERIOR SOUTHEAST GEORGIA PRIOR TO SUNRISE...BUT HAS SLOWED DOWN
THE LINE/S PROGRESS FROM PREVIOUS RUNS. THIS TREND MAY PERSIST
FOR THE NEXT SEVERAL RUNS GIVEN OUTPUT FROM THE 18Z LOWER
RESOLUTION MODEL SUITE. ALTHOUGH SIGNIFICANT SURFACE BASED
INSTABILITY WILL BE LACKING--SBCAPE 500-700 J/KG AT BEST--STRONG
SHEAR AND AN IMPRESSIVE LOW-LEVEL JET COULD SUPPORT A FEW STRONG
TSTMS OVERNIGHT WITH GUSTY WINDS BEING THE PRIMARY HAZARD.
ALTHOUGH NOT IMPOSSIBLE...THE RISK FOR ORGANIZED SEVERE TSTMS
TONIGHT IS ONLY SLIGHTLY ELEVATED...AT LEAST THROUGH SUNRISE.

IT WILL BE A RELATIVELY WARM AND MUGGY NIGHT FOR THE AREA WITH THE
LATEST TEMPERATURE DATA SUPPORTING SLIGHTLY WARMER OVERNIGHT
LOWS...ESPECIALLY EAST OF I-95. LOWS WILL RANGE FROM THE MID 60S
WELL INLAND TO AROUND 70 DEGREES AT THE COAST. ITS VERY POSSIBLE
LOWS COULD BE SLIGHTLY WARMER...ESPECIALLY ALONG THE LOWER SOUTH
CAROLINA COAST.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...VERY ACTIVE DAY AS A STRONG COLD FRONT APPROACHES FROM THE
WEST EARLY IN THE MORNING...THEN PUSHES OFFSHORE LATER IN THE
AFTERNOON. AHEAD OF THE FRONT UNSEASONABLY MOIST AND POSSIBLY WARM
AIR WILL MOVE INTO THE AREA. VERY STRONG WIND FIELDS WILL BE IN
PLACE AS LOW PRESSURE INTENSIFIES ALONG THE FRONT. AS USUAL FOR THIS
TIME OF YEAR...INSTABILITY IS THE BIGGEST QUESTION...BUT THERE
SHOULD BE ENOUGH IN THE LOWER LEVELS TO AT LEAST YIELD SOME STRONGER
STORMS AS TEMPS PUSH INTO THE MID TO UPPER 70S. SOME GUIDANCE
INDICATES LOWER TO MID 80S AROUND CHARLESTON...AND IF THIS WERE
TO BE THE CASE...INSTABILITY WILL BE PLENTY SUFFICIENT FOR SEVERE
STORMS. ALTHOUGH DAMAGING WINDS WILL BE THE MAIN HAZARD...LOW-LEVEL
HELICITY VALUES LOOK HIGH ENOUGH TO WARRANT AT LEAST A LOW END
TORNADO RISK AS WELL. EVEN OUTSIDE ANY STORMS...THE PRESSURE
GRADIENT WILL BE STRONG ENOUGH TO MAKE FOR A BREEZY TO POTENTIALLY
WINDY DAY...WITH THE STRONGEST WINDS MOST LIKELY ALONG THE SC
COAST UP INTO THE CHARLESTON METRO AREA. A WIND ADVISORY MAY
EVENTUALLY BE NEEDED...AND AT THE VERY LEAST A WIND ADVISORY FOR
LAKE MOULTRIE. THE FRONT SHOULD PUSH INTO THE ATLANTIC LATER IN
THE AFTERNOON WITH RAIN CHANCES QUICKLY ENDING THEREAFTER AS MUCH
DRIER AIR FILTERS IN FROM THE WEST. TEMPS BY DAYBREAK WEDNESDAY
WILL BE AROUND 40 INLAND WITH LOWER TO MID 40S AT THE COAST.

WEDNESDAY...DRY AND BREEZY WITH TEMPS WELL BELOW NORMAL AS COOL HIGH
PRESSURE BUILDS FROM THE NORTH. ANY ATLANTIC SHOWERS SHOULD REMAIN
OFFSHORE. HIGHS LIKELY NEAR 60 NORTH WITH MID 60S SOUTH. ANOTHER
CHILLY NIGHT WEDNESDAY NIGHT WITH TEMPS LIKELY INTO THE UPPER 30S
WELL INLAND AND MID/UPPER 40S ALONG THE SC COAST AND LOWER 50S ALONG
THE GA COAST.

THURSDAY...PRETTY MUCH A CARBON COPY OF WEDNESDAY EXCEPT A LITTLE
WARMER.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR LATE IN THE WEEK INTO EASTER WEEKEND IS A FAIRLY
LOW CONFIDENCE FORECAST IN REGARDS TO EXACT DETAILS. HOWEVER...THE
MID WEEK WEDGE OF HIGH PRESSURE EVENTUALLY STARTS TO ERODE ON
FRIDAY...AS A TROUGH OF LOW PRESSURE FORMS OVER THE SW ATLANTIC AND
WAVES OF LOW PRESSURE DEVELOP ALONG THE PRE-EXISTING BAROCLINIC ZONE
OVER THE OCEAN AND/OR A MORE PRONOUNCED LOW ARRIVES FROM OUT OF THE
GULF OF MEXICO FOR SATURDAY. DRIER HIGH PRESSURE EITHER WAY LOOKS TO
BUILD BACK IN FOR EASTER DAY AND NEXT MONDAY AS WELL. TEMPS LOOK TO
BE NEAR OR SLIGHTLY ABOVE CLIMATOLOGY THROUGH THE PERIOD. AT LEAST
SOME RAIN CHANCE IS EVIDENT THROUGH SATURDAY.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
VFR THROUGH THE NIGHT AND INTO MUCH OF THE DAY TUESDAY. SLIGHT
CHANCE FOR A BRIEF PERIOD OF MVFR CIGS THIS EVENING...BUT ANY CIGS
SHOULD SCOUR OUT AS STRONG 35-40 KT LOW-LEVEL JETTING INITIATES.
WINDS SHOULD REMAIN HIGH ENOUGH OVERNIGHT TO PRECLUDE LOW-LEVEL
WIND SHEAR UNLESS DIRECTION DIFFERENTIALS REACH 60 DEGS WHICH IS
UNLIKELY. SOME LIGHT SHOWER ACTIVITY WILL REMAIN EAST OF KCHS FOR
MUCH OF THE NIGHT...BUT SHOULD NOT IMPACT THE TERMINAL. VERY GUSTY
WINDS ARE EXPECTED AT BOTH TERMINALS TUESDAY AS A STRONG COLD
FRONT MOVES IN FROM THE WEST. HIGH PROBABILITY FOR FREQUENT GUSTS
OF 25-30 KT WITH OCCASIONAL HIGHER GUSTS. A LINE OF STRONG TSTMS
WILL REACH THE TERMINALS MID-LATE AFTERNOON...POSSIBLY IN THE FORM
OF A SQUALL LINE. WILL INTRODUCE A CONSERVATIVE MVFR VSBY IN
TSRA BEGINNING AT 19Z AT KSAV AND 20Z AT KCHS...BUT LOWER
CONDITIONS MAY VERY WELL BE NEEDED FOR A PERIOD.

EXTENDED AVIATION OUTLOOK...SHOWERS AND STORMS WILL BE PASSING EAST
OF THE TERMS LATER TUE AFTERNOON WITH IMPROVING CONDITIONS.
HOWEVER...WIND GUSTS WILL CONTINUE AND BE THE DOMINANT IMPACT INTO
LATE WEEK. SUB-VFR WEATHER AGAIN POSSIBLE LATE WEDNESDAY NIGHT OR
THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM OFF THE
ATLANTIC...THEN POSSIBLY A BETTER CHANCE INTO SATURDAY AS LOW
PRESSURE MOVES OUT OF THE GULF OF MEXICO AND OVER THE AREA OR JUST
OFFSHORE.

&&

.MARINE...
TONIGHT...SEAS AT 41004 AND 41008 ARE RUNNING ABOUT 1-2 FT HIGHER
THAN THE LATEST WW4 RUN. ASSUMING THIS TREND CONTINUES AS WINDS
INCREASE TO 15 KT NEARSHORE...15-20 KT OFFSHORE...SEAS WILL REACH
SMALL CRAFT ADVISORY THRESHOLDS A LITTLE EARLIER THAN PREVIOUSLY
THOUGHT. ADJUSTED THE START TIME OF THE VARIOUS ADVISORIES GIVEN
THIS.

TUESDAY THROUGH SATURDAY...A COLD FRONT APPROACHING FROM THE WEST
TUESDAY WILL KEEP A STRONG PRESSURE GRADIENT IN PLACE OVER THE LOCAL
WATERS AND ADVISORIES ARE EXPECTED FOR ALL WATERS. THERE IS THE
POTENTIAL THAT WINDS COULD GUST NEAR GALE FORCE...ESPECIALLY ACROSS
FAR INLAND PORTIONS OF CHARLESTON HARBOR WHERE BETTER MIXING IS
EXPECTED OVER LAND AREAS DURING THE AFTERNOON UNTIL THE FRONT PASSES
LATER IN THE AFTERNOON. OTHERWISE...THE STRONG GRADIENT WILL REMAIN
IN PLACE THROUGH MID WEEK AS COOL HIGH PRESSURE BUILDS FROM THE
NORTH AND THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO
FRIDAY...ALTHOUGH POSSIBLY ENDING THURSDAY IN CHARLESTON HARBOR.

RIP CURRENTS...STRONG SOUTH TO SOUTHWEST WINDS AHEAD OF AN
APPROACHING COLD FRONT WILL COMBINE WITH ASTRONOMICAL INFLUENCES
FROM THE FULL MOON TO RESULT IN AN ENHANCED RISK FOR RIP CURRENTS ON
TUESDAY. LOOKS LIKE A HIGH RISK ALONG THE SC COAST AND A MODERATE
RISK ALONG THE GA COAST. BEHIND THE FRONT BEGINNING WEDNESDAY...STRONG
NORTH/NORTHEAST WINDS ARE EXPECTED THROUGH AT LEAST FRIDAY. AS
SUCH...THE ENHANCED RISK FOR RIP CURRENTS WILL CONTINUE THROUGH THE
REMAINDER OF THE WEEK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...HIGH RISK FOR RIP CURRENTS FROM 8 AM EDT TUESDAY THROUGH
     TUESDAY EVENING FOR SCZ048>051.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM TUESDAY TO 5 PM EDT FRIDAY FOR
     AMZ352.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT FRIDAY FOR AMZ350.
     SMALL CRAFT ADVISORY FROM 2 PM TUESDAY TO 5 PM EDT FRIDAY FOR
     AMZ354.
     SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM TUESDAY TO 5 PM EDT THURSDAY
     FOR AMZ330.

&&

$$

ST







000
FXUS62 KCHS 150118
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
918 PM EDT MON APR 14 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH THE AREA FROM THE WEST EARLY
TUESDAY...POSSIBLY ACCOMPANIED BY SEVERE THUNDERSTORMS...THEN PUSH
OFFSHORE LATER IN THE AFTERNOON. UNSEASONABLY COOL HIGH PRESSURE
WILL FOLLOW BEHIND THE FRONT AND CONTINUE THROUGH THURSDAY. A WAVE
OF LOW PRESSURE COULD SKIRT THE AREA FROM OUT OF THE GULF LATE IN
THE WEEK...BEFORE HIGH PRESSURE RETURNS FOR EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A WELL-DEFINED OUTFLOW BOUNDARY IS BECOMING INCREASINGLY MORE
DEFINED ACROSS CENTRAL GEORGIA THIS EVENING PER KJGX REFLECTIVITY
DATA. SHOWERS/TSTMS HAVE BEEN SLOWLY INCREASING IN COVERAGE
ACROSS CENTRAL GEORGIA...THE CSRA...THE WESTERN MIDLANDS AND MORE
RECENTLY FAR INTERIOR SOUTHEAST GEORGIA IN RESPONSE TO A
STRENGTHENING NOCTURNAL LOW-LEVEL JET. GUIDANCE IS STILL SHOWING A
SPREAD IN THE COVERAGE OF SHOWER/TSTM ACTIVITY THAT WILL AFFECT
THE AREA OVERNIGHT...BUT RECENT RADAR TRENDS SUGGEST AN INCREASE
IN POPS TO 50 PERCENT IS WARRANTED FOR OVER THE FAR WESTERN ZONES
FROM ROUGHLY ALLENDALE TO REIDSVILLE AND POINTS WEST. THE H3R
STILL DEPICTS A LINE OF SHOWERS/TSTMS APPROACHING THE FAR
INTERIOR SOUTHEAST GEORGIA PRIOR TO SUNRISE...BUT HAS SLOWED DOWN
THE LINE/S PROGRESS FROM PREVIOUS RUNS. THIS TREND MAY PERSIST
FOR THE NEXT SEVERAL RUNS GIVEN OUTPUT FROM THE 18Z LOWER
RESOLUTION MODEL SUITE. ALTHOUGH SIGNIFICANT SURFACE BASED
INSTABILITY WILL BE LACKING--SBCAPE 500-700 J/KG AT BEST--STRONG
SHEAR AND AN IMPRESSIVE LOW-LEVEL JET COULD SUPPORT A FEW STRONG
TSTMS OVERNIGHT WITH GUSTY WINDS BEING THE PRIMARY HAZARD.
ALTHOUGH NOT IMPOSSIBLE...THE RISK FOR ORGANIZED SEVERE TSTMS
TONIGHT IS ONLY SLIGHTLY ELEVATED...AT LEAST THROUGH SUNRISE.

IT WILL BE A RELATIVELY WARM AND MUGGY NIGHT FOR THE AREA WITH THE
LATEST TEMPERATURE DATA SUPPORTING SLIGHTLY WARMER OVERNIGHT
LOWS...ESPECIALLY EAST OF I-95. LOWS WILL RANGE FROM THE MID 60S
WELL INLAND TO AROUND 70 DEGREES AT THE COAST. ITS VERY POSSIBLE
LOWS COULD BE SLIGHTLY WARMER...ESPECIALLY ALONG THE LOWER SOUTH
CAROLINA COAST.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...VERY ACTIVE DAY AS A STRONG COLD FRONT APPROACHES FROM THE
WEST EARLY IN THE MORNING...THEN PUSHES OFFSHORE LATER IN THE
AFTERNOON. AHEAD OF THE FRONT UNSEASONABLY MOIST AND POSSIBLY WARM
AIR WILL MOVE INTO THE AREA. VERY STRONG WIND FIELDS WILL BE IN
PLACE AS LOW PRESSURE INTENSIFIES ALONG THE FRONT. AS USUAL FOR THIS
TIME OF YEAR...INSTABILITY IS THE BIGGEST QUESTION...BUT THERE
SHOULD BE ENOUGH IN THE LOWER LEVELS TO AT LEAST YIELD SOME STRONGER
STORMS AS TEMPS PUSH INTO THE MID TO UPPER 70S. SOME GUIDANCE
INDICATES LOWER TO MID 80S AROUND CHARLESTON...AND IF THIS WERE
TO BE THE CASE...INSTABILITY WILL BE PLENTY SUFFICIENT FOR SEVERE
STORMS. ALTHOUGH DAMAGING WINDS WILL BE THE MAIN HAZARD...LOW-LEVEL
HELICITY VALUES LOOK HIGH ENOUGH TO WARRANT AT LEAST A LOW END
TORNADO RISK AS WELL. EVEN OUTSIDE ANY STORMS...THE PRESSURE
GRADIENT WILL BE STRONG ENOUGH TO MAKE FOR A BREEZY TO POTENTIALLY
WINDY DAY...WITH THE STRONGEST WINDS MOST LIKELY ALONG THE SC
COAST UP INTO THE CHARLESTON METRO AREA. A WIND ADVISORY MAY
EVENTUALLY BE NEEDED...AND AT THE VERY LEAST A WIND ADVISORY FOR
LAKE MOULTRIE. THE FRONT SHOULD PUSH INTO THE ATLANTIC LATER IN
THE AFTERNOON WITH RAIN CHANCES QUICKLY ENDING THEREAFTER AS MUCH
DRIER AIR FILTERS IN FROM THE WEST. TEMPS BY DAYBREAK WEDNESDAY
WILL BE AROUND 40 INLAND WITH LOWER TO MID 40S AT THE COAST.

WEDNESDAY...DRY AND BREEZY WITH TEMPS WELL BELOW NORMAL AS COOL HIGH
PRESSURE BUILDS FROM THE NORTH. ANY ATLANTIC SHOWERS SHOULD REMAIN
OFFSHORE. HIGHS LIKELY NEAR 60 NORTH WITH MID 60S SOUTH. ANOTHER
CHILLY NIGHT WEDNESDAY NIGHT WITH TEMPS LIKELY INTO THE UPPER 30S
WELL INLAND AND MID/UPPER 40S ALONG THE SC COAST AND LOWER 50S ALONG
THE GA COAST.

THURSDAY...PRETTY MUCH A CARBON COPY OF WEDNESDAY EXCEPT A LITTLE
WARMER.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR LATE IN THE WEEK INTO EASTER WEEKEND IS A FAIRLY
LOW CONFIDENCE FORECAST IN REGARDS TO EXACT DETAILS. HOWEVER...THE
MID WEEK WEDGE OF HIGH PRESSURE EVENTUALLY STARTS TO ERODE ON
FRIDAY...AS A TROUGH OF LOW PRESSURE FORMS OVER THE SW ATLANTIC AND
WAVES OF LOW PRESSURE DEVELOP ALONG THE PRE-EXISTING BAROCLINIC ZONE
OVER THE OCEAN AND/OR A MORE PRONOUNCED LOW ARRIVES FROM OUT OF THE
GULF OF MEXICO FOR SATURDAY. DRIER HIGH PRESSURE EITHER WAY LOOKS TO
BUILD BACK IN FOR EASTER DAY AND NEXT MONDAY AS WELL. TEMPS LOOK TO
BE NEAR OR SLIGHTLY ABOVE CLIMATOLOGY THROUGH THE PERIOD. AT LEAST
SOME RAIN CHANCE IS EVIDENT THROUGH SATURDAY.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
VFR THROUGH THE NIGHT AND INTO MUCH OF THE DAY TUESDAY. SLIGHT
CHANCE FOR A BRIEF PERIOD OF MVFR CIGS THIS EVENING...BUT ANY CIGS
SHOULD SCOUR OUT AS STRONG 35-40 KT LOW-LEVEL JETTING INITIATES.
WINDS SHOULD REMAIN HIGH ENOUGH OVERNIGHT TO PRECLUDE LOW-LEVEL
WIND SHEAR UNLESS DIRECTION DIFFERENTIALS REACH 60 DEGS WHICH IS
UNLIKELY. SOME LIGHT SHOWER ACTIVITY WILL REMAIN EAST OF KCHS FOR
MUCH OF THE NIGHT...BUT SHOULD NOT IMPACT THE TERMINAL. VERY GUSTY
WINDS ARE EXPECTED AT BOTH TERMINALS TUESDAY AS A STRONG COLD
FRONT MOVES IN FROM THE WEST. HIGH PROBABILITY FOR FREQUENT GUSTS
OF 25-30 KT WITH OCCASIONAL HIGHER GUSTS. A LINE OF STRONG TSTMS
WILL REACH THE TERMINALS MID-LATE AFTERNOON...POSSIBLY IN THE FORM
OF A SQUALL LINE. WILL INTRODUCE A CONSERVATIVE MVFR VSBY IN
TSRA BEGINNING AT 19Z AT KSAV AND 20Z AT KCHS...BUT LOWER
CONDITIONS MAY VERY WELL BE NEEDED FOR A PERIOD.

EXTENDED AVIATION OUTLOOK...SHOWERS AND STORMS WILL BE PASSING EAST
OF THE TERMS LATER TUE AFTERNOON WITH IMPROVING CONDITIONS.
HOWEVER...WIND GUSTS WILL CONTINUE AND BE THE DOMINANT IMPACT INTO
LATE WEEK. SUB-VFR WEATHER AGAIN POSSIBLE LATE WEDNESDAY NIGHT OR
THURSDAY THROUGH FRIDAY AS MOISTURE RETURNS FROM OFF THE
ATLANTIC...THEN POSSIBLY A BETTER CHANCE INTO SATURDAY AS LOW
PRESSURE MOVES OUT OF THE GULF OF MEXICO AND OVER THE AREA OR JUST
OFFSHORE.

&&

.MARINE...
TONIGHT...SEAS AT 41004 AND 41008 ARE RUNNING ABOUT 1-2 FT HIGHER
THAN THE LATEST WW4 RUN. ASSUMING THIS TREND CONTINUES AS WINDS
INCREASE TO 15 KT NEARSHORE...15-20 KT OFFSHORE...SEAS WILL REACH
SMALL CRAFT ADVISORY THRESHOLDS A LITTLE EARLIER THAN PREVIOUSLY
THOUGHT. ADJUSTED THE START TIME OF THE VARIOUS ADVISORIES GIVEN
THIS.

TUESDAY THROUGH SATURDAY...A COLD FRONT APPROACHING FROM THE WEST
TUESDAY WILL KEEP A STRONG PRESSURE GRADIENT IN PLACE OVER THE LOCAL
WATERS AND ADVISORIES ARE EXPECTED FOR ALL WATERS. THERE IS THE
POTENTIAL THAT WINDS COULD GUST NEAR GALE FORCE...ESPECIALLY ACROSS
FAR INLAND PORTIONS OF CHARLESTON HARBOR WHERE BETTER MIXING IS
EXPECTED OVER LAND AREAS DURING THE AFTERNOON UNTIL THE FRONT PASSES
LATER IN THE AFTERNOON. OTHERWISE...THE STRONG GRADIENT WILL REMAIN
IN PLACE THROUGH MID WEEK AS COOL HIGH PRESSURE BUILDS FROM THE
NORTH AND THUS ADVISORIES ARE EXPECTED TO CONTINUE INTO
FRIDAY...ALTHOUGH POSSIBLY ENDING THURSDAY IN CHARLESTON HARBOR.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...HIGH RISK FOR RIP CURRENTS FROM 8 AM EDT TUESDAY THROUGH
     TUESDAY EVENING FOR SCZ048>051.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM TUESDAY TO 5 PM EDT FRIDAY FOR
     AMZ352.
     SMALL CRAFT ADVISORY FROM 2 AM TUESDAY TO 5 PM EDT FRIDAY FOR
     AMZ350.
     SMALL CRAFT ADVISORY FROM 2 PM TUESDAY TO 5 PM EDT FRIDAY FOR
     AMZ354.
     SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ374.
     SMALL CRAFT ADVISORY FROM 11 AM TUESDAY TO 5 PM EDT THURSDAY
     FOR AMZ330.

&&

$$









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