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000
FXUS62 KCHS 170822
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
422 AM EDT WED SEP 17 2014

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE REGION THROUGH TONIGHT.
AN INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF
THE FRONT INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM
THE WEST EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...AREAS OF LAYERED CLOUDS ACROSS THE FORECAST AREA THIS
MORNING WITH AREAS OF STRATUS CLOUDS AND FOG DEVELOPING ACROSS
INLAND SOUTH CAROLINA WHERE WIDESPREAD RAINS RE-SATURATED THE
SOILS AGAIN ON TUESDAY. THE LOW CLOUDS COULD CERTAINLY EXPAND EAST
AND SOUTH BY DAYBREAK WITH AREAS OF FOG EXPECTED. AT THIS POINT...
WIDESPREAD DENSE FOG PROBLEMS DO NOT LOOK TOO LIKELY GIVEN LATEST
BUFR FORECAST SOUNDINGS WITH HIGH MOISTURE PROFILES UP TO 850 MB.
A FEW INLAND AREAS COULD SEE VSBYS 1/2 MILE OR LESS AT TIMES.
ISOLATED SHOWERS ARE POSSIBLE JUST ABOUT ANYWHERE NORTH OF
BEAUFORT NEARING DAWN...BUT THE BULK OF THE CONVECTION WILL
PROBABLY REMAIN EITHER CLOSER TO THE BEACHES...JUST OFFSHORE OR
MOSTLY N OF THE AREA.

WEAK CYCLOGENESIS WILL OCCUR OFF THE GEORGIA AND SOUTH CAROLINA
COASTS THIS MORNING AS INCREASING CYCLONIC FLOW ALOFT SPREADS OVER
THE SOUTHEAST STATES TODAY. DEEPER MOISTURE AND ENHANCED UPPER
FORCING WILL ALSO BE ASSOCIATED WITH THE EXITING LOW PRES OFF THE
COAST. IN THE LOW LEVELS A FAIRLY DISORGANIZED BACKDOOR SURFACE
COLD FRONT IS FORECAST TO SLIDE THROUGH THE FORECAST AREA TODAY
IN THE WAKE OF THE ATLC LOW PRES MOVING OUT.

IT LOOKS LIKE MAINLY ISOLATED CONVECTION FOR THE MORNING HOURS
WITH A ROUND OF SCATTERED SHOWERS AND STORMS FOR THIS AFTERNOON
AND EVENING AS A SERIES OF MID LEVEL SHORT WAVE TROUGHS RIPPLE
E AND SE THROUGH GEORGIA AND SOUTH CAROLINA. COVERAGE/DURATION
SHOULD BE LESS OVER SOUTH CAROLINA TODAY BUT WE WILL HAVE TO
WATCH FOR A REGION OF UPPER DIFLUENCE PROGGED BY JUST ABOUT ALL
THE MODELS LATE DAY. UPPER FORCING COULD ENHANCE THE CONVECTIVE
POTENTIAL DURING THE LATE AFTERNOON HOURS ACROSS PARTS OF E
CENTRAL OR NE SOUTH CAROLINA. WE RAISED POPS INTO THE 40 PERCENT
RANGE NE OF WALTERBORO TO ACCOUNT FOR THIS POTENTIAL. OTHERWISE...
TYPICAL LATE SUMMER THERMODYNAMICS ANTICIPATED WITH JUST ENOUGH
MID/UPPER FLOW TO SUGGEST SOME MULTI-CELL ORGANIZATION AT TIMES.
WE CANNOT RULE OUT ISOLATED STRONG TSTMS EITHER BUT CONFIDENCE
WITH THE MESOSCALE IS QUITE LOW WITH THE WEAKLY SLOPED FRONTAL
ZONE IN THE AREA. SOME OF THE TSTMS WILL ALSO PRODUCE DOWNPOURS
WHICH WILL WILL BE SLOW TO RUN OFF AROUND HIGH TIDE IF STORMS CROP
UP ALONG THE COAST TOWARD MID AFTERNOON. DEEP LAYERED STEERING IS
ALSO GENERALLY TOWARD THE COAST AS WELL.

TONIGHT...LATER SHIFTS CAN TAKE A HARDER LOOK AT LATE NIGHT FOG
POTENTIAL BUT CHANCES SEEM TO BE THERE NEARING DAWN ON THU.
POPS SHIFT OFFSHORE LATER IN THE EVENING WITH PARTLY CLOUDY
SKIES MOST AREA.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY...THE COLD FRONT WILL STEADILY PROGRESS OFFSHORE AND
EVENTUALLY PULL NORTH/NORTHEAST...AS A WAVE OF LOW PRESSURE
DEVELOPS ALONG THE FEATURE AND LIFTS AHEAD OF SHORTWAVE ENERGY IN
THE BASE OF THE UPPER TROUGH. HIGH PRESSURE OVER THE GREAT LAKES
REGION WILL SLOWLY BUILD TOWARD THE MID ATLANTIC STATES AND
CAROLINAS BEHIND THE DEPARTING FRONT...INTRODUCING A NOTABLY DRIER
AIR MASS INTO THE FORECAST AREA. ANY ISOLATED SHOWER ACTIVITY ON
THURSDAY WILL LIKELY BE CONFINED TO THE CHARLESTON TRI COUNTY
REGION AND SC/GA COASTAL COUNTIES...WHERE SEABREEZE AND COASTAL
CONVERGENCE COULD PROVIDE SOME FORCING FOR WEAK CONVECTION. HIGH
TEMPERATURES WILL REFLECT A COOLING TREND...PEAKING IN THE LOW TO
MID 80S UNDER PARTLY CLOUDY SKIES. LOW TEMPERATURES WILL ALSO BE
NOTABLY COOLER...FALLING INTO THE MID TO UPPER 60S OVERNIGHT. BEST
RAIN CHANCES DURING THE NIGHTTIME PERIOD WILL BE FOUND OVER THE
MARINE ZONES...HOWEVER AN ISOLATED SHOWER COULD MOVE INTO THE
COASTLINE WITHIN ONSHORE FLOW.

FRIDAY AND SATURDAY...AS THE CENTER OF HIGH PRESSURE TO THE NORTH
MOVES OVER THE NEW ENGLAND STATES FRIDAY AND SHIFTS OFF THE
NORTHERN COASTLINE SATURDAY...AN INLAND WEDGE WILL AMPLIFY DOWN
THE MID ATLANTIC AND SOUTHEAST STATES. THE UPPER TROUGH WILL
GRADUALLY DIMINISH LATE WEEK INTO THE WEEKEND...WHILE A WEAK
UPPER LOW TAKES SHAPE JUST OFF THE SOUTHEAST COAST. EXPECT THE
ENERGY WITHIN THIS FEATURE TO SUPPORT THE DEVELOPMENT OF A WELL-
DEFINED COASTAL TROUGH AT THE SURFACE. BEST RAIN POTENTIAL WILL
MAINLY BE FOUND ALONG THE COAST AND OVER THE MARINE
ZONES...CLOSEST TO MOISTURE AND CONVERGENCE WITHIN THE COASTAL
TROUGH. HAVE THUS INDICATED A DISTINCT WEST-EAST GRADIENT IN RAIN
CHANCES FRIDAY AND SATURDAY...WITH SLIGHT CHANCES LESS THAN 25
PERCENT ACROSS INLAND ZONES THAT INCREASE TO SOLID CHANCES IN THE
30 TO 40 PERCENT RANGE FOR COASTAL COUNTIES...HIGHEST DURING THE
AFTERNOON PERIODS. COOL NORTHEAST FLOW WITHIN THE INLAND WEDGE OF
HIGH PRESSURE WILL SUPPRESS TEMPERATURES BELOW SEASONAL
NORMALS...RISING ONLY INTO THE LOWER 80S EACH DAY. LOW
TEMPERATURES FRIDAY NIGHT WILL TREND EVEN COOLER THAN THE PREVIOUS
DAY...RANGING FROM THE LOW TO MID 60S AWAY FROM THE LOCALLY WARMER
COASTLINE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
A COASTAL TROUGH ON THE PERIPHERY OF INLAND HIGH PRESSURE WILL
LIFT NORTH/NORTHEAST ACROSS THE ATLANTIC WATERS SUNDAY...WHILE
THE INLAND WEDGE EVENTUALLY ERODES AHEAD OF A STRONG COLD FRONT
UPSTREAM. PRECIPITATION POTENTIAL ON SUNDAY WILL BE SIMILAR TO
PREVIOUS DAYS...MAINLY FOCUSED ACROSS THE COASTAL COUNTIES WITH
RAIN-FREE CONDITIONS FARTHER INLAND. THE COLD FRONT WILL CONTINUE
TO APPROACH FROM THE NORTHWEST ON MONDAY...AS A PRE-FRONTAL SURFACE
TROUGH SHIFTS OVER THE EAST COAST STATES. THE COLD FRONT THEN
STEADILY MOVES THROUGH THE FORECAST AREA EARLY TUESDAY...FOLLOWED
BY EXPANSIVE HIGH PRESSURE WITH ORIGINS FROM THE NORTHERN PLAINS.
MEDIUM RANGE MODEL SOLUTIONS ARE NOT INDICATING SIGNIFICANT
PRECIPITATION ASSOCIATED WITH THE FRONTAL PASSAGE...AND HAVE THUS
CAPPED RAIN CHANCES GENERALLY BELOW 30 PERCENT FOR THE EARLY WEEK
PERIOD. TEMPERATURES COULD REBOUND AHEAD OF THE FRONT ON MONDAY AND
PEAK IN THE MID TO UPPER 80S...BEFORE A NOTABLE COOLING TREND
OCCURS IN THE WAKE OF THE FRONT TUESDAY AND WEDNESDAY.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
LOW STRATUS WAS DEVELOPING PRIOR TO 08Z W AND N OF KCHS AND WE
EXPECT IFR CONDITIONS TO SET IN LATER TONIGHT AS THESE LOW CLOUDS
EXPAND. THERE COULD ALSO BE FOG WITH VSBYS BELOW 1 NM BUT AT THIS
TIME CONFIDENCE IS BETTER ON LOW CIGS. AT KSAV,,,WE TRENDED A BIT
MORE OPTIMISTIC LATER TONIGHT WITH MVFR VSBYS AND SCATTERED LOW
CLOUDS IN THE FIRST COUPLE HUNDRED FEET. IF COULD BECOME IFR OR
LOWER BUT FORECAST SOUNDINGS ARE FAR FROM CONCLUSIVE.

LOW CIGS AND ANY FOG AROUND AT DAYBREAK SHOULD GIVEN WAY TO VFR
CONDITIONS BY LATE MORNING INTO THE AFTERNOON HOURS. THERE ARE
ADDITIONAL CHANCES FOR SCATTERED SHOWERS AND TSTMS AGAIN THIS
AFTERNOON...WE HAVE VCSH AFTER MIDDAY TO TREND.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
GROUND SWELL FROM DISTANT MAJOR HURRICANE EDOUARD TRICKLING INTO OUR
COASTAL WATERS EARLY THIS MORNING...AND ADDITIONAL SWELL ENERGY IS
TO ARRIVE AS TIME PROGRESSES. SEAS 2 FT NEAR SHORE WILL BUILD TO
3 TO 4 FT WELL OFFSHORE TODAY INTO TONIGHT. AS A COLD FRONT MOVES
THROUGH THIS MORNING LIGHT AND VARIABLE WINDS SHOULD BECOME MORE
ONSHORE BUT SPEEDS MAINLY 10 KT OR LESS THROUGH TONIGHT. THE
SUBTLE LONG PERIOD SWELL COULD MAKE FOR LOCALLY ROUGH CONDITIONS
AROUND THE JETTIES...ESPECIALLY AROUND TIMES OF LOW TIDE.

THURSDAY THROUGH SUNDAY...LIGHT NORTHEAST WINDS BEHIND THE COLD
FRONT ON THURSDAY WILL BEGIN TO SURGE BY FRIDAY...AS A WEDGE OF
HIGH PRESSURE STRENGTHENS INLAND AND A COASTAL TROUGH AMPLIFIES
TO THE SOUTHEAST. WINDS WILL INCREASE TO 15 TO 20 KT ACROSS
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...WHILE SEAS
BUILD TO 3 TO 5 FT. LATEST NUMERICAL MODEL SOLUTIONS SUGGEST
CONDITIONS WILL REMAIN JUST BELOW SMALL CRAFT ADVISORY CRITERIA
AT THIS TIME. CONDITIONS SHOULD MODERATE OVER THE WATERS AS THE
INLAND WEDGE WEAKENS BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES TODAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...1-2 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS TODAY...AND
POSSIBLY THURSDAY.

&&

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

&&

$$

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







000
FXUS62 KCHS 170822
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
422 AM EDT WED SEP 17 2014

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE REGION THROUGH TONIGHT.
AN INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF
THE FRONT INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM
THE WEST EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...AREAS OF LAYERED CLOUDS ACROSS THE FORECAST AREA THIS
MORNING WITH AREAS OF STRATUS CLOUDS AND FOG DEVELOPING ACROSS
INLAND SOUTH CAROLINA WHERE WIDESPREAD RAINS RE-SATURATED THE
SOILS AGAIN ON TUESDAY. THE LOW CLOUDS COULD CERTAINLY EXPAND EAST
AND SOUTH BY DAYBREAK WITH AREAS OF FOG EXPECTED. AT THIS POINT...
WIDESPREAD DENSE FOG PROBLEMS DO NOT LOOK TOO LIKELY GIVEN LATEST
BUFR FORECAST SOUNDINGS WITH HIGH MOISTURE PROFILES UP TO 850 MB.
A FEW INLAND AREAS COULD SEE VSBYS 1/2 MILE OR LESS AT TIMES.
ISOLATED SHOWERS ARE POSSIBLE JUST ABOUT ANYWHERE NORTH OF
BEAUFORT NEARING DAWN...BUT THE BULK OF THE CONVECTION WILL
PROBABLY REMAIN EITHER CLOSER TO THE BEACHES...JUST OFFSHORE OR
MOSTLY N OF THE AREA.

WEAK CYCLOGENESIS WILL OCCUR OFF THE GEORGIA AND SOUTH CAROLINA
COASTS THIS MORNING AS INCREASING CYCLONIC FLOW ALOFT SPREADS OVER
THE SOUTHEAST STATES TODAY. DEEPER MOISTURE AND ENHANCED UPPER
FORCING WILL ALSO BE ASSOCIATED WITH THE EXITING LOW PRES OFF THE
COAST. IN THE LOW LEVELS A FAIRLY DISORGANIZED BACKDOOR SURFACE
COLD FRONT IS FORECAST TO SLIDE THROUGH THE FORECAST AREA TODAY
IN THE WAKE OF THE ATLC LOW PRES MOVING OUT.

IT LOOKS LIKE MAINLY ISOLATED CONVECTION FOR THE MORNING HOURS
WITH A ROUND OF SCATTERED SHOWERS AND STORMS FOR THIS AFTERNOON
AND EVENING AS A SERIES OF MID LEVEL SHORT WAVE TROUGHS RIPPLE
E AND SE THROUGH GEORGIA AND SOUTH CAROLINA. COVERAGE/DURATION
SHOULD BE LESS OVER SOUTH CAROLINA TODAY BUT WE WILL HAVE TO
WATCH FOR A REGION OF UPPER DIFLUENCE PROGGED BY JUST ABOUT ALL
THE MODELS LATE DAY. UPPER FORCING COULD ENHANCE THE CONVECTIVE
POTENTIAL DURING THE LATE AFTERNOON HOURS ACROSS PARTS OF E
CENTRAL OR NE SOUTH CAROLINA. WE RAISED POPS INTO THE 40 PERCENT
RANGE NE OF WALTERBORO TO ACCOUNT FOR THIS POTENTIAL. OTHERWISE...
TYPICAL LATE SUMMER THERMODYNAMICS ANTICIPATED WITH JUST ENOUGH
MID/UPPER FLOW TO SUGGEST SOME MULTI-CELL ORGANIZATION AT TIMES.
WE CANNOT RULE OUT ISOLATED STRONG TSTMS EITHER BUT CONFIDENCE
WITH THE MESOSCALE IS QUITE LOW WITH THE WEAKLY SLOPED FRONTAL
ZONE IN THE AREA. SOME OF THE TSTMS WILL ALSO PRODUCE DOWNPOURS
WHICH WILL WILL BE SLOW TO RUN OFF AROUND HIGH TIDE IF STORMS CROP
UP ALONG THE COAST TOWARD MID AFTERNOON. DEEP LAYERED STEERING IS
ALSO GENERALLY TOWARD THE COAST AS WELL.

TONIGHT...LATER SHIFTS CAN TAKE A HARDER LOOK AT LATE NIGHT FOG
POTENTIAL BUT CHANCES SEEM TO BE THERE NEARING DAWN ON THU.
POPS SHIFT OFFSHORE LATER IN THE EVENING WITH PARTLY CLOUDY
SKIES MOST AREA.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY...THE COLD FRONT WILL STEADILY PROGRESS OFFSHORE AND
EVENTUALLY PULL NORTH/NORTHEAST...AS A WAVE OF LOW PRESSURE
DEVELOPS ALONG THE FEATURE AND LIFTS AHEAD OF SHORTWAVE ENERGY IN
THE BASE OF THE UPPER TROUGH. HIGH PRESSURE OVER THE GREAT LAKES
REGION WILL SLOWLY BUILD TOWARD THE MID ATLANTIC STATES AND
CAROLINAS BEHIND THE DEPARTING FRONT...INTRODUCING A NOTABLY DRIER
AIR MASS INTO THE FORECAST AREA. ANY ISOLATED SHOWER ACTIVITY ON
THURSDAY WILL LIKELY BE CONFINED TO THE CHARLESTON TRI COUNTY
REGION AND SC/GA COASTAL COUNTIES...WHERE SEABREEZE AND COASTAL
CONVERGENCE COULD PROVIDE SOME FORCING FOR WEAK CONVECTION. HIGH
TEMPERATURES WILL REFLECT A COOLING TREND...PEAKING IN THE LOW TO
MID 80S UNDER PARTLY CLOUDY SKIES. LOW TEMPERATURES WILL ALSO BE
NOTABLY COOLER...FALLING INTO THE MID TO UPPER 60S OVERNIGHT. BEST
RAIN CHANCES DURING THE NIGHTTIME PERIOD WILL BE FOUND OVER THE
MARINE ZONES...HOWEVER AN ISOLATED SHOWER COULD MOVE INTO THE
COASTLINE WITHIN ONSHORE FLOW.

FRIDAY AND SATURDAY...AS THE CENTER OF HIGH PRESSURE TO THE NORTH
MOVES OVER THE NEW ENGLAND STATES FRIDAY AND SHIFTS OFF THE
NORTHERN COASTLINE SATURDAY...AN INLAND WEDGE WILL AMPLIFY DOWN
THE MID ATLANTIC AND SOUTHEAST STATES. THE UPPER TROUGH WILL
GRADUALLY DIMINISH LATE WEEK INTO THE WEEKEND...WHILE A WEAK
UPPER LOW TAKES SHAPE JUST OFF THE SOUTHEAST COAST. EXPECT THE
ENERGY WITHIN THIS FEATURE TO SUPPORT THE DEVELOPMENT OF A WELL-
DEFINED COASTAL TROUGH AT THE SURFACE. BEST RAIN POTENTIAL WILL
MAINLY BE FOUND ALONG THE COAST AND OVER THE MARINE
ZONES...CLOSEST TO MOISTURE AND CONVERGENCE WITHIN THE COASTAL
TROUGH. HAVE THUS INDICATED A DISTINCT WEST-EAST GRADIENT IN RAIN
CHANCES FRIDAY AND SATURDAY...WITH SLIGHT CHANCES LESS THAN 25
PERCENT ACROSS INLAND ZONES THAT INCREASE TO SOLID CHANCES IN THE
30 TO 40 PERCENT RANGE FOR COASTAL COUNTIES...HIGHEST DURING THE
AFTERNOON PERIODS. COOL NORTHEAST FLOW WITHIN THE INLAND WEDGE OF
HIGH PRESSURE WILL SUPPRESS TEMPERATURES BELOW SEASONAL
NORMALS...RISING ONLY INTO THE LOWER 80S EACH DAY. LOW
TEMPERATURES FRIDAY NIGHT WILL TREND EVEN COOLER THAN THE PREVIOUS
DAY...RANGING FROM THE LOW TO MID 60S AWAY FROM THE LOCALLY WARMER
COASTLINE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
A COASTAL TROUGH ON THE PERIPHERY OF INLAND HIGH PRESSURE WILL
LIFT NORTH/NORTHEAST ACROSS THE ATLANTIC WATERS SUNDAY...WHILE
THE INLAND WEDGE EVENTUALLY ERODES AHEAD OF A STRONG COLD FRONT
UPSTREAM. PRECIPITATION POTENTIAL ON SUNDAY WILL BE SIMILAR TO
PREVIOUS DAYS...MAINLY FOCUSED ACROSS THE COASTAL COUNTIES WITH
RAIN-FREE CONDITIONS FARTHER INLAND. THE COLD FRONT WILL CONTINUE
TO APPROACH FROM THE NORTHWEST ON MONDAY...AS A PRE-FRONTAL SURFACE
TROUGH SHIFTS OVER THE EAST COAST STATES. THE COLD FRONT THEN
STEADILY MOVES THROUGH THE FORECAST AREA EARLY TUESDAY...FOLLOWED
BY EXPANSIVE HIGH PRESSURE WITH ORIGINS FROM THE NORTHERN PLAINS.
MEDIUM RANGE MODEL SOLUTIONS ARE NOT INDICATING SIGNIFICANT
PRECIPITATION ASSOCIATED WITH THE FRONTAL PASSAGE...AND HAVE THUS
CAPPED RAIN CHANCES GENERALLY BELOW 30 PERCENT FOR THE EARLY WEEK
PERIOD. TEMPERATURES COULD REBOUND AHEAD OF THE FRONT ON MONDAY AND
PEAK IN THE MID TO UPPER 80S...BEFORE A NOTABLE COOLING TREND
OCCURS IN THE WAKE OF THE FRONT TUESDAY AND WEDNESDAY.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
LOW STRATUS WAS DEVELOPING PRIOR TO 08Z W AND N OF KCHS AND WE
EXPECT IFR CONDITIONS TO SET IN LATER TONIGHT AS THESE LOW CLOUDS
EXPAND. THERE COULD ALSO BE FOG WITH VSBYS BELOW 1 NM BUT AT THIS
TIME CONFIDENCE IS BETTER ON LOW CIGS. AT KSAV,,,WE TRENDED A BIT
MORE OPTIMISTIC LATER TONIGHT WITH MVFR VSBYS AND SCATTERED LOW
CLOUDS IN THE FIRST COUPLE HUNDRED FEET. IF COULD BECOME IFR OR
LOWER BUT FORECAST SOUNDINGS ARE FAR FROM CONCLUSIVE.

LOW CIGS AND ANY FOG AROUND AT DAYBREAK SHOULD GIVEN WAY TO VFR
CONDITIONS BY LATE MORNING INTO THE AFTERNOON HOURS. THERE ARE
ADDITIONAL CHANCES FOR SCATTERED SHOWERS AND TSTMS AGAIN THIS
AFTERNOON...WE HAVE VCSH AFTER MIDDAY TO TREND.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
GROUND SWELL FROM DISTANT MAJOR HURRICANE EDOUARD TRICKLING INTO OUR
COASTAL WATERS EARLY THIS MORNING...AND ADDITIONAL SWELL ENERGY IS
TO ARRIVE AS TIME PROGRESSES. SEAS 2 FT NEAR SHORE WILL BUILD TO
3 TO 4 FT WELL OFFSHORE TODAY INTO TONIGHT. AS A COLD FRONT MOVES
THROUGH THIS MORNING LIGHT AND VARIABLE WINDS SHOULD BECOME MORE
ONSHORE BUT SPEEDS MAINLY 10 KT OR LESS THROUGH TONIGHT. THE
SUBTLE LONG PERIOD SWELL COULD MAKE FOR LOCALLY ROUGH CONDITIONS
AROUND THE JETTIES...ESPECIALLY AROUND TIMES OF LOW TIDE.

THURSDAY THROUGH SUNDAY...LIGHT NORTHEAST WINDS BEHIND THE COLD
FRONT ON THURSDAY WILL BEGIN TO SURGE BY FRIDAY...AS A WEDGE OF
HIGH PRESSURE STRENGTHENS INLAND AND A COASTAL TROUGH AMPLIFIES
TO THE SOUTHEAST. WINDS WILL INCREASE TO 15 TO 20 KT ACROSS
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...WHILE SEAS
BUILD TO 3 TO 5 FT. LATEST NUMERICAL MODEL SOLUTIONS SUGGEST
CONDITIONS WILL REMAIN JUST BELOW SMALL CRAFT ADVISORY CRITERIA
AT THIS TIME. CONDITIONS SHOULD MODERATE OVER THE WATERS AS THE
INLAND WEDGE WEAKENS BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES TODAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...1-2 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS TODAY...AND
POSSIBLY THURSDAY.

&&

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

&&

$$

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








000
FXUS62 KCHS 170531
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
131 AM EDT WED SEP 17 2014

.SYNOPSIS...
A TROUGH WILL MOVE THROUGH THE AREA THIS MORNING....FOLLOWED BY A
STRONG COLD FRONT APPROACHING FROM THE NORTHWEST LATE TONIGHT AND
PUSHING THROUGH THE REGION LATE WEDNESDAY. AN INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT INTO THE
WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPSTREAM CONVECTION HAS WEAKENED OVER THE CSRA BUT REMAINING
ROBUST AND PERSISTENT ACROSS NORTHERN PARTS OF SOUTH CAROLINA.
MODELS CONTINUE TO KEEP THE BULK OF THIS CONVECTION NORTH AND
TREND TOWARD WEAKENING OVERNIGHT. AXIS OF DEEPEST MOISTURE WAS
SLIDING SE OVERNIGHT AND WHILE ADDITIONAL COASTAL RAINS ARE
POSSIBLE...THEY WILL TEND TO REMAIN OFFSHORE FOR THE MOST PART
AS A WEAK WAVE OF LOW PRES DEVELOPS ALONG THE GULF STREAM.

GIVEN SATURATED GROUNDS FROM SUBSTANTIAL RAINFALL EARLIER IN THE
DAY AND LIGHT/NEARLY CALM SURFACE WINDS...FOG/STRATUS WILL BE AN
ISSUE ONCE AGAIN LATE TONIGHT. THUS HAVE MAINTAINED AREAS OF FOG
MENTION IN THE GRIDS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
LOW STRATUS WAS DEVELOPING PRIOR TO 06Z W AND N OF KCHS AND WE
EXPECTED IFR CONDITIONS TO SET IN LATER TONIGHT AS THESE LOW
CLOUDS EXPAND. THERE COULD ALSO BE FOG WITH VSBYS BELOW 1 NM
BUT AT THIS TIME CONFIDENCE IS BETTER ON LOW CIGS. AT KSAV,,,WE
TRENDED A BIT MORE OPTIMISTIC LATER TONIGHT WITH MVFR VSBYS AND
SCATTERED LOW CLOUDS IN THE FIRST COUPLE HUNDRED FEET. IF COULD
BECOME IFR OR LOWER BUT FORECAST SOUNDINGS ARE FAR FROM CONCLUSIVE.

LOW CIGS AND ANY FOG AROUND AT DAYBREAK SHOULD GIVEN WAY TO VFR
CONDITIONS BY LATE MORNING INTO THE AFTERNOON HOURS. THERE ARE
ADDITIONAL CHANCES FOR SCATTERED SHOWERS AND TSTMS AGAIN THIS
AFTERNOON...WE HAVE VCSH AFTER MIDDAY TO TREND.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
OVERNIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 FT ORE LESS ...BUILDING ANOTHER FOOT OR TWO LATE.
MEANWHILE...WITH A WEAK PRESSURE PATTERN OUR WIND FIELDS WILL BE
DRIVEN BY A WEAK SURFACE TROUGH DROPPING THROUGH FROM THE
NORTH/NW... AND THE LAND BREEZE CIRCULATION. THIS ALLOWS WINDS TO
VEER TO THE WEST BY MIDNIGHT...THEN AROUND TO THE NW OR NORTH
LATE. OUTSIDE OF THE CONVECTION WINDS WILL OBTAIN NO MORE THAN
ABOUT 10 KT. THERE IS ALSO A MODERATE TO HIGH PROBABILITY OF FOG
IMPACTING THE CHARLESTON HARBOR LATE IN THE OVERNIGHT PERIOD. BE
SAFE ON THE COASTAL WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

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

&&

$$

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







000
FXUS62 KCHS 170300
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1100 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATE EVENING UPDATE...HAVE ADJUSTED POPS BASED ON CURRENT RADAR
TRENDS. ALSO MADE TWEAKS TO TEMP TRENDS DUE TO ATYPICAL DIURNAL
CURVE AS A RESULT OF CONVECTION.

OVERALL...THE PERSISTENT AFTERNOON/EVENING CONVECTION HAS
WEAKENED DUE TO LOSS OF INSOLATION/NOCTURNAL STABILIZATION.
HOWEVER GIVEN SEVERAL REMNANT MESOSCALE BOUNDARIES...THERE IS
STILL SOME NUISANCE ACTIVITY MAINLY ACROSS OUR GEORGIA ZONES. DESPITE
THIS...THE RISK FOR FLASH FLOODING HAS ENDED AND THE FLASH FLOOD
WATCH HAS BEEN CANCELLED. SHOULD SEE MOST ACTIVITY SHIFT OFF THE
COAST BY 06Z.

GIVEN SATURATED GROUNDS FROM SUBSTANTIAL RAINFALL EARLIER IN THE
DAY AND LIGHT/NEARLY CALM SURFACE WINDS...FOG/STRATUS WILL BE AN
ISSUE ONCE AGAIN LATE TONIGHT. THUS HAVE MAINTAINED AREAS OF FOG
MENTION IN THE GRIDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
LINGERING SHOWERS MAY AFFECT KSAV THROUGH 06Z...THEN ACTIVITY IS
EXPECTED TO WANE. GIVEN THE EXTREMELY WET GROUNDS...LITTLE TO NO
WINDS AND A DECENT NOCTURNAL INVERSION TO FORM WE LOOK FOR LOW
STRATUS AND/OR FOG LATE TONIGHT INTO WEDNESDAY MORNING. MVFR OR
LOWER CONDITIONS ARE AGAIN A POSSIBILITY...BEFORE VFR CONDITIONS
RETURN AFTER 13-14Z WEDNESDAY.

ISOLATED TO SCATTERED SHRA/TSRA WILL DEVELOP IN ADVANCE OF THE
COLD FRONT WEDNESDAY AFTERNOON/EVENING...AND WITH THE INTERACTION
OF THE SEA BREEZE THERE CERTAINLY COULD BE SUB-VFR WEATHER LATE IN
THE VALID 00Z TAF CYCLE. WE/LL LET FUTURE TAFS ADDRESS THIS
CONCERN AS PROBABILITIES ARE NOT YET HIGH ENOUGH TO INCLUDE WITH
THE MOST RECENT SET OF TAFS.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A WEAK SURFACE TROUGH
DROPPING THROUGH FROM THE NORTH/NW... AND THE LAND BREEZE
CIRCULATION. THIS ALLOWS WINDS TO VEER TO THE WEST BY
MIDNIGHT...THEN AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE
CONVECTION WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT.
THERE IS ALSO A MODERATE TO HIGH PROBABILITY OF FOG IMPACTING THE
CHARLESTON HARBOR LATE IN THE OVERNIGHT PERIOD. BE SAFE ON THE
COASTAL WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

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

&&

$$

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








000
FXUS62 KCHS 170300
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1100 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATE EVENING UPDATE...HAVE ADJUSTED POPS BASED ON CURRENT RADAR
TRENDS. ALSO MADE TWEAKS TO TEMP TRENDS DUE TO ATYPICAL DIURNAL
CURVE AS A RESULT OF CONVECTION.

OVERALL...THE PERSISTENT AFTERNOON/EVENING CONVECTION HAS
WEAKENED DUE TO LOSS OF INSOLATION/NOCTURNAL STABILIZATION.
HOWEVER GIVEN SEVERAL REMNANT MESOSCALE BOUNDARIES...THERE IS
STILL SOME NUISANCE ACTIVITY MAINLY ACROSS OUR GEORGIA ZONES. DESPITE
THIS...THE RISK FOR FLASH FLOODING HAS ENDED AND THE FLASH FLOOD
WATCH HAS BEEN CANCELLED. SHOULD SEE MOST ACTIVITY SHIFT OFF THE
COAST BY 06Z.

GIVEN SATURATED GROUNDS FROM SUBSTANTIAL RAINFALL EARLIER IN THE
DAY AND LIGHT/NEARLY CALM SURFACE WINDS...FOG/STRATUS WILL BE AN
ISSUE ONCE AGAIN LATE TONIGHT. THUS HAVE MAINTAINED AREAS OF FOG
MENTION IN THE GRIDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
LINGERING SHOWERS MAY AFFECT KSAV THROUGH 06Z...THEN ACTIVITY IS
EXPECTED TO WANE. GIVEN THE EXTREMELY WET GROUNDS...LITTLE TO NO
WINDS AND A DECENT NOCTURNAL INVERSION TO FORM WE LOOK FOR LOW
STRATUS AND/OR FOG LATE TONIGHT INTO WEDNESDAY MORNING. MVFR OR
LOWER CONDITIONS ARE AGAIN A POSSIBILITY...BEFORE VFR CONDITIONS
RETURN AFTER 13-14Z WEDNESDAY.

ISOLATED TO SCATTERED SHRA/TSRA WILL DEVELOP IN ADVANCE OF THE
COLD FRONT WEDNESDAY AFTERNOON/EVENING...AND WITH THE INTERACTION
OF THE SEA BREEZE THERE CERTAINLY COULD BE SUB-VFR WEATHER LATE IN
THE VALID 00Z TAF CYCLE. WE/LL LET FUTURE TAFS ADDRESS THIS
CONCERN AS PROBABILITIES ARE NOT YET HIGH ENOUGH TO INCLUDE WITH
THE MOST RECENT SET OF TAFS.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A WEAK SURFACE TROUGH
DROPPING THROUGH FROM THE NORTH/NW... AND THE LAND BREEZE
CIRCULATION. THIS ALLOWS WINDS TO VEER TO THE WEST BY
MIDNIGHT...THEN AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE
CONVECTION WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT.
THERE IS ALSO A MODERATE TO HIGH PROBABILITY OF FOG IMPACTING THE
CHARLESTON HARBOR LATE IN THE OVERNIGHT PERIOD. BE SAFE ON THE
COASTAL WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

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

&&

$$

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







000
FXUS62 KCHS 162332
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
732 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THIS EVENING...WE HAVE SEEN CONSIDERABLE BACK-BUILDING OF
CONVECTION AS THE WEST/NW STEERING MOTION RUNS INTO THE SEA BREEZE
BOUNDARY AND JUST PILES UP DUE TO THE INTERACTION OF THESE
PROMINENT FEATURES. WE STILL HAVE THE FLASH FLOOD WATCH GOING
UNTIL 8 PM SINCE THERE IS STILL AN ONGOING FLASH FLOOD WARNING FOR
CHARLESTON COUNTY WHERE NUMEROUS ROADS HAVE BEEN CLOSED...MAINLY
IN DOWNTOWN. SINCE WE STILL HAVE ROADS CLOSED IN DOWNTOWN
CHARLESTON AND RAIN ONGOING OR FORECAST TO MOVE BACK INTO THE
COASTAL ZONES AND PARTS OF SE GA WHERE WE HAVE THE FLASH FLOOD
WATCH ONGOING...WE HAVE EXTENDED THE WATCH UNTIL 11 PM. COULD ALSO
EXPERIENCE HEAVY ENOUGH RAINS IN A FEW OTHER NEARBY COUNTIES...BUT
THESE WILL BE HANDLED IN A FLASH FLOOD ADVISORY OR POSSIBLE WARNING.

EARLIER WE SAW A COUPLE OF MARGINALLY SEVERE STORMS IN CHATHAM
AND BEAUFORT COUNTIES WITH A FEW REPORTS OF TREES DOWN. SBCAPES
AND DCAPES ARE DECREASING...SO THE RISK OF ANY ADDITIONAL SEVERE
WEATHER IS VERY LOW...BUT NOT ZERO.

CONVECTION WILL BEGIN TO WANE DURING THE LATE EVENING AS CINH
REDEVELOPS AND THE TYPICAL NOCTURNAL COOLING/STABILIZATION TAKES
PLACE. HOWEVER...GIVEN NUMEROUS BOUNDARY INTERACTIONS THAT WILL
CONTINUE WE HAVE HELD ONTO ISOLATED POPS FAR INLAND AND SCATTERED
POPS FURTHER SOUTH AND EAST THROUGH AT LEAST 03-05Z. THE HIGH
RESOLUTION MODEL GUIDANCE IS INDICATING THAT CONVECTION WILL
ATTEMPT TO MERGE FROM NEAR BEAUFORT COUNTY SOUTH TO THE ALTAMAHA
LATE THIS EVENING AND WE MAY HAVE TO EXTEND THE FLASH FLOOD WATCH
FOR THESE COUNTIES IF THIS COMES TO FRUITION. BY DAYBREAK
WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV. MVFR
OR LOWER CONDITIONS ARE LIKELY AS A RESULT...WITH HEAVY RAINS AND
GUSTY WINDS ALSO A CONCERN...ESPECIALLY AT KSAV.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN THE EXTREMELY WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

ISOLATED TO SCATTERED SHRA/TSRA WILL DEVELOP IN ADVANCE OF THE
COLD FRONT WEDNESDAY AFTERNOON/EVENING...AND WITH THE INTERACTION
OF THE SEA BREEZE THERE CERTAINLY COULD BE SUB-VFR WEATHER LATE IN
THE VALID 00Z TAF CYCLE. WE/LL LET FUTURE TAFS ADDRESS THIS
CONCERN AS PROBABILITIES ARE NOT YET HIGH ENOUGH TO INCLUDE WITH
THE MOST RECENT SET OF TAFS.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. THERE IS ALSO A
MODERATE TO HIGH PROBABILITY OF FOG IMPACTING THE CHARLESTON
HARBOR LATE IN THE OVERNIGHT PERIOD. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN EXTENDED IN TIME FOR AREAS SOUTH OF
I-16 IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS STILL HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 162332
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
732 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THIS EVENING...WE HAVE SEEN CONSIDERABLE BACK-BUILDING OF
CONVECTION AS THE WEST/NW STEERING MOTION RUNS INTO THE SEA BREEZE
BOUNDARY AND JUST PILES UP DUE TO THE INTERACTION OF THESE
PROMINENT FEATURES. WE STILL HAVE THE FLASH FLOOD WATCH GOING
UNTIL 8 PM SINCE THERE IS STILL AN ONGOING FLASH FLOOD WARNING FOR
CHARLESTON COUNTY WHERE NUMEROUS ROADS HAVE BEEN CLOSED...MAINLY
IN DOWNTOWN. SINCE WE STILL HAVE ROADS CLOSED IN DOWNTOWN
CHARLESTON AND RAIN ONGOING OR FORECAST TO MOVE BACK INTO THE
COASTAL ZONES AND PARTS OF SE GA WHERE WE HAVE THE FLASH FLOOD
WATCH ONGOING...WE HAVE EXTENDED THE WATCH UNTIL 11 PM. COULD ALSO
EXPERIENCE HEAVY ENOUGH RAINS IN A FEW OTHER NEARBY COUNTIES...BUT
THESE WILL BE HANDLED IN A FLASH FLOOD ADVISORY OR POSSIBLE WARNING.

EARLIER WE SAW A COUPLE OF MARGINALLY SEVERE STORMS IN CHATHAM
AND BEAUFORT COUNTIES WITH A FEW REPORTS OF TREES DOWN. SBCAPES
AND DCAPES ARE DECREASING...SO THE RISK OF ANY ADDITIONAL SEVERE
WEATHER IS VERY LOW...BUT NOT ZERO.

CONVECTION WILL BEGIN TO WANE DURING THE LATE EVENING AS CINH
REDEVELOPS AND THE TYPICAL NOCTURNAL COOLING/STABILIZATION TAKES
PLACE. HOWEVER...GIVEN NUMEROUS BOUNDARY INTERACTIONS THAT WILL
CONTINUE WE HAVE HELD ONTO ISOLATED POPS FAR INLAND AND SCATTERED
POPS FURTHER SOUTH AND EAST THROUGH AT LEAST 03-05Z. THE HIGH
RESOLUTION MODEL GUIDANCE IS INDICATING THAT CONVECTION WILL
ATTEMPT TO MERGE FROM NEAR BEAUFORT COUNTY SOUTH TO THE ALTAMAHA
LATE THIS EVENING AND WE MAY HAVE TO EXTEND THE FLASH FLOOD WATCH
FOR THESE COUNTIES IF THIS COMES TO FRUITION. BY DAYBREAK
WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV. MVFR
OR LOWER CONDITIONS ARE LIKELY AS A RESULT...WITH HEAVY RAINS AND
GUSTY WINDS ALSO A CONCERN...ESPECIALLY AT KSAV.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN THE EXTREMELY WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

ISOLATED TO SCATTERED SHRA/TSRA WILL DEVELOP IN ADVANCE OF THE
COLD FRONT WEDNESDAY AFTERNOON/EVENING...AND WITH THE INTERACTION
OF THE SEA BREEZE THERE CERTAINLY COULD BE SUB-VFR WEATHER LATE IN
THE VALID 00Z TAF CYCLE. WE/LL LET FUTURE TAFS ADDRESS THIS
CONCERN AS PROBABILITIES ARE NOT YET HIGH ENOUGH TO INCLUDE WITH
THE MOST RECENT SET OF TAFS.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. THERE IS ALSO A
MODERATE TO HIGH PROBABILITY OF FOG IMPACTING THE CHARLESTON
HARBOR LATE IN THE OVERNIGHT PERIOD. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN EXTENDED IN TIME FOR AREAS SOUTH OF
I-16 IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS STILL HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 162311
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
711 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THIS EVENING...WE HAVE SEEN CONSIDERABLE BACK-BUILDING OF
CONVECTION AS THE WEST/NW STEERING MOTION RUNS INTO THE SEA BREEZE
BOUNDARY AND JUST PILES UP DUE TO THE INTERACTION OF THESE
PROMINENT FEATURES. WE STILL HAVE THE FLASH FLOOD WATCH GOING
UNTIL 8 PM SINCE THERE IS STILL AN ONGOING FLASH FLOOD WARNING FOR
CHARLESTON COUNTY WHERE NUMEROUS ROADS HAVE BEEN CLOSED...MAINLY
IN DOWNTOWN. WE ALSO SAW A COUPLE OF MARGINALLY SEVERE STORMS IN
CHATHAM AND BEAUFORT COUNTIES WITH A FEW REPORTS OF TREES DOWN.
SBCAPES AND DCAPES ARE DECREASING...SO THE RISK OF ANY ADDITIONAL
SEVERE WEATHER IS VERY LOW...BUT NOT ZERO.

CONVECTION WILL BEGIN TO WANE DURING THE LATE EVENING AS CINH
REDEVELOPS AND THE TYPICAL NOCTURNAL COOLING/STABILIZATION TAKES
PLACE. HOWEVER...GIVEN NUMEROUS BOUNDARY INTERACTIONS THAT WILL
CONTINUE WE HAVE HELD ONTO ISOLATED POPS FAR INLAND AND SCATTERED
POPS FURTHER SOUTH AND EAST THROUGH AT LEAST 03-05Z. THE HIGH
RESOLUTION MODEL GUIDANCE IS INDICATING THAT CONVECTION WILL
ATTEMPT TO MERGE FROM NEAR BEAUFORT COUNTY SOUTH TO THE ALTAMAHA
LATE THIS EVENING AND WE MAY HAVE TO EXTEND THE FLASH FLOOD WATCH
FOR THESE COUNTIES IF THIS COMES TO FRUITION. BY DAYBREAK
WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV. MVFR
OR LOWER CONDITIONS ARE LIKELY AS A RESULT...WITH HEAVY RAINS AND
GUSTY WINDS ALSO A CONCERN.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN THE EXTREMELY WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

ISOLATED TO SCATTERED SHRA/TSRA WILL DEVELOP IN ADVANCE OF THE
COLD FRONT WEDNESDAY AFTERNOON/EVENING...AND WITH THE INTERACTION
OF THE SEA BREEZE THERE CERTAINLY COULD BE SUB-VFR WEATHER LATE IN
THE VALID 00Z TAF CYCLE. WE/LL LET FUTURE TAFS ADDRESS THIS
CONCERN AS PROBABILITIES ARE NOT YET HIGH ENOUGH TO INCLUDE WITH
THE MOST RECENT SET OF TAFS.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. THERE IS ALSO A
MODERATE TO HIGH PROBABILITY OF FOG IMPACTING THE CHARLESTON
HARBOR LATE IN THE OVERNIGHT PERIOD. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC...SO NO REASON TO DEVIATE FROM THE
EARLIER ISSUANCE OF THE FLASH FLOOD WATCH.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 162311
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
711 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THIS EVENING...WE HAVE SEEN CONSIDERABLE BACK-BUILDING OF
CONVECTION AS THE WEST/NW STEERING MOTION RUNS INTO THE SEA BREEZE
BOUNDARY AND JUST PILES UP DUE TO THE INTERACTION OF THESE
PROMINENT FEATURES. WE STILL HAVE THE FLASH FLOOD WATCH GOING
UNTIL 8 PM SINCE THERE IS STILL AN ONGOING FLASH FLOOD WARNING FOR
CHARLESTON COUNTY WHERE NUMEROUS ROADS HAVE BEEN CLOSED...MAINLY
IN DOWNTOWN. WE ALSO SAW A COUPLE OF MARGINALLY SEVERE STORMS IN
CHATHAM AND BEAUFORT COUNTIES WITH A FEW REPORTS OF TREES DOWN.
SBCAPES AND DCAPES ARE DECREASING...SO THE RISK OF ANY ADDITIONAL
SEVERE WEATHER IS VERY LOW...BUT NOT ZERO.

CONVECTION WILL BEGIN TO WANE DURING THE LATE EVENING AS CINH
REDEVELOPS AND THE TYPICAL NOCTURNAL COOLING/STABILIZATION TAKES
PLACE. HOWEVER...GIVEN NUMEROUS BOUNDARY INTERACTIONS THAT WILL
CONTINUE WE HAVE HELD ONTO ISOLATED POPS FAR INLAND AND SCATTERED
POPS FURTHER SOUTH AND EAST THROUGH AT LEAST 03-05Z. THE HIGH
RESOLUTION MODEL GUIDANCE IS INDICATING THAT CONVECTION WILL
ATTEMPT TO MERGE FROM NEAR BEAUFORT COUNTY SOUTH TO THE ALTAMAHA
LATE THIS EVENING AND WE MAY HAVE TO EXTEND THE FLASH FLOOD WATCH
FOR THESE COUNTIES IF THIS COMES TO FRUITION. BY DAYBREAK
WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV. MVFR
OR LOWER CONDITIONS ARE LIKELY AS A RESULT...WITH HEAVY RAINS AND
GUSTY WINDS ALSO A CONCERN.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN THE EXTREMELY WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

ISOLATED TO SCATTERED SHRA/TSRA WILL DEVELOP IN ADVANCE OF THE
COLD FRONT WEDNESDAY AFTERNOON/EVENING...AND WITH THE INTERACTION
OF THE SEA BREEZE THERE CERTAINLY COULD BE SUB-VFR WEATHER LATE IN
THE VALID 00Z TAF CYCLE. WE/LL LET FUTURE TAFS ADDRESS THIS
CONCERN AS PROBABILITIES ARE NOT YET HIGH ENOUGH TO INCLUDE WITH
THE MOST RECENT SET OF TAFS.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. THERE IS ALSO A
MODERATE TO HIGH PROBABILITY OF FOG IMPACTING THE CHARLESTON
HARBOR LATE IN THE OVERNIGHT PERIOD. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC...SO NO REASON TO DEVIATE FROM THE
EARLIER ISSUANCE OF THE FLASH FLOOD WATCH.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 162246
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
646 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THIS EVENING...WE HAVE SEEN CONSIDERABLE BACK-BUILDING OF
CONVECTION AS THE WEST/NW STEERING MOTION RUNS INTO THE SEA BREEZE
BOUNDARY AND JUST PILES UP DUE TO THE INTERACTION OF THESE
PROMINENT FEATURES. WE STILL HAVE THE FLASH FLOOD WATCH GOING
UNTIL 8 PM SINCE THERE IS STILL AN ONGOING FLASH FLOOD WARNING FOR
CHARLESTON COUNTY WHERE NUMEROUS ROADS HAVE BEEN CLOSED...MAINLY
IN DOWNTOWN. WE ALSO SAW A COUPLE OF MARGINALLY SEVERE STORMS IN
CHATHAM AND BEAUFORT COUNTIES WITH A FEW REPORTS OF TREES DOWN.
SBCAPES AND DCAPES ARE DECREASING...SO THE RISK OF ANY ADDITIONAL
SEVERE WEATHER IS VERY LOW...BUT NOT ZERO.

CONVECTION WILL BEGIN TO WANE DURING THE LATE EVENING AS CINH
REDEVELOPS AND THE TYPICAL NOCTURNAL COOLING/STABILIZATION TAKES
PLACE. HOWEVER...GIVEN NUMEROUS BOUNDARY INTERACTIONS THAT WILL
CONTINUE WE HAVE HELD ONTO ISOLATED POPS FAR INLAND AND SCATTERED
POPS FURTHER SOUTH AND EAST THROUGH AT LEAST 03-05Z. THE HIGH
RESOLUTION MODEL GUIDANCE IS INDICATING THAT CONVECTION WILL
ATTEMPT TO MERGE FROM NEAR BEAUFORT COUNTY SOUTH TO THE ALTAMAHA
LATE THIS EVENING AND WE MAY HAVE TO EXTEND THE FLASH FLOOD WATCH
FOR THESE COUNTIES IF THIS COMES TO FRUITION. BY DAYBREAK
WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV. MVFR
OR LOWER CONDITIONS ARE LIKELY AS A RESULT...WITH HEAVY RAINS AND
GUSTY WINDS ALSO A CONCERN.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR SOME LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. THERE IS ALSO A
MODERATE TO HIGH PROBABILITY OF FOG IMPACTING THE CHARLESTON
HARBOR LATE IN THE OVERNIGHT PERIOD. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC...SO NO REASON TO DEVIATE FROM THE
EARLIER ISSUANCE OF THE FLASH FLOOD WATCH.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 162246
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
646 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THIS EVENING...WE HAVE SEEN CONSIDERABLE BACK-BUILDING OF
CONVECTION AS THE WEST/NW STEERING MOTION RUNS INTO THE SEA BREEZE
BOUNDARY AND JUST PILES UP DUE TO THE INTERACTION OF THESE
PROMINENT FEATURES. WE STILL HAVE THE FLASH FLOOD WATCH GOING
UNTIL 8 PM SINCE THERE IS STILL AN ONGOING FLASH FLOOD WARNING FOR
CHARLESTON COUNTY WHERE NUMEROUS ROADS HAVE BEEN CLOSED...MAINLY
IN DOWNTOWN. WE ALSO SAW A COUPLE OF MARGINALLY SEVERE STORMS IN
CHATHAM AND BEAUFORT COUNTIES WITH A FEW REPORTS OF TREES DOWN.
SBCAPES AND DCAPES ARE DECREASING...SO THE RISK OF ANY ADDITIONAL
SEVERE WEATHER IS VERY LOW...BUT NOT ZERO.

CONVECTION WILL BEGIN TO WANE DURING THE LATE EVENING AS CINH
REDEVELOPS AND THE TYPICAL NOCTURNAL COOLING/STABILIZATION TAKES
PLACE. HOWEVER...GIVEN NUMEROUS BOUNDARY INTERACTIONS THAT WILL
CONTINUE WE HAVE HELD ONTO ISOLATED POPS FAR INLAND AND SCATTERED
POPS FURTHER SOUTH AND EAST THROUGH AT LEAST 03-05Z. THE HIGH
RESOLUTION MODEL GUIDANCE IS INDICATING THAT CONVECTION WILL
ATTEMPT TO MERGE FROM NEAR BEAUFORT COUNTY SOUTH TO THE ALTAMAHA
LATE THIS EVENING AND WE MAY HAVE TO EXTEND THE FLASH FLOOD WATCH
FOR THESE COUNTIES IF THIS COMES TO FRUITION. BY DAYBREAK
WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV. MVFR
OR LOWER CONDITIONS ARE LIKELY AS A RESULT...WITH HEAVY RAINS AND
GUSTY WINDS ALSO A CONCERN.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR SOME LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. THERE IS ALSO A
MODERATE TO HIGH PROBABILITY OF FOG IMPACTING THE CHARLESTON
HARBOR LATE IN THE OVERNIGHT PERIOD. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC...SO NO REASON TO DEVIATE FROM THE
EARLIER ISSUANCE OF THE FLASH FLOOD WATCH.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 162115
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
515 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH THIS EVENING...WATER VAPOR SATELLITE IMAGES SHOWING A
COUPLE OF MID LEVEL IMPULSES HEADING OUR WAY FROM UPSTREAM. ONE IS
OVER SOUTHERN GA AND THE SECOND IS A STRUNG OUT BUT PRONOUNCED
VORT LOBE ENTERING THE UPSTATE OF SC AND INTO NORTHERN GA. THESE
FEATURES WILL IMPACT THE AREA INTO THIS EVENING...AND THAT PLUS
UPPER DIFLUENCE ASSOCIATED WITH THE RIGHT REAR QUAD OF AN 250 MB
JET WILL SUPPLY THE NECESSARY FORCING FOR ASCENT. MEANWHILE THERE
IS STILL AN ABUNDANCE OF MOISTURE...UP ALMOST AT 2 STANDARD
DEVIATIONS ABOVE NORMAL. STEERING FLOW IS A LITTLE MORE NOTICEABLE
THAN RECENT DAYS...BUT STILL SLOW ENOUGH TO SUPPORT LIMITED
MOVEMENT TO OUR SHOWERS AND T-STORMS. PLUS THE CONVECTION WILL BE
STEERED TOWARD THE COAST WITH THE WEST/NW FLOW AND WILL BUMP UP
AGAINST THE PINNED SEA BREEZE...WHICH IMPLIES THAT A PILING UP OF
RAINFALL CAN OCCUR AS IT HAS NOWHERE FURTHER EAST OR SE TO
GO...STUCK AT THE SEA BREEZE BOUNDARY. WE ARE STILL HITTING THE
COASTAL ZONES OF SC AND AREAS SOUTH OF I-16 IN SE GA WITH THE
FLASH FLOOD WATCH THROUGH 8 PM...AND IT/S IN THESE AREAS THAT HAVE
THE HIGHEST POPS IN THE 60-80 PERCENT RANGE. FURTHER WEST AND NW
WE/LL RELY ON BOUNDARY INTERACTIONS TO POP ANY CONVECTION...AND
POPS ARE HELD TO 30-40 PERCENT DURING THE SECOND HALF OF THE
AFTERNOON.

ALSO OF NOTE...THERE IS A TAD BIT DRIER AND COLDER AIR IN THE MID
LEVELS AND MORE MOVEMENT IN THE TROPOSPHERE THAN OF LATE.
MODIFIED 12Z SOUNDINGS AND RECENT SPC MESO-ANALYSIS HAS SOME
DECENT THERMODYNAMICS....PERHAPS SUPPORTIVE A FEW STRONGER OR
EVEN MARGINALLY SEVERE STORMS WHERE THE BOUNDARY
INTERACTIONS...MERGERS AND/OR COLLISIONS OCCUR. THIS IS A LOW END
PROBABILITY...BUT WORTHY OF TALKING ABOUT WITH FREQUENT LIGHTNING
AND STRONG DOWNBURSTS OF WIND POSSIBLE IN A COUPLE OF THE TALLER
STORMS.

FOR TONIGHT...CONVECTION WILL BEGIN TO WANE DURING THE LATE
EVENING AS CINH REDEVELOPS AND THE TYPICAL NOCTURNAL
COOLING/STABILIZATION TAKES PLACE. HOWEVER...GIVEN NUMEROUS
BOUNDARY INTERACTIONS THAT WILL CONTINUE WE HAVE HELD ONTO
ISOLATED POPS FAR INLAND AND SCATTERED POPS FURTHER SOUTH AND EAST
THROUGH AT LEAST 03-05Z. THE HIGH RESOLUTION MODEL GUIDANCE IS
INDICATING THAT CONVECTION WILL ATTEMPT TO MERGE FROM NEAR BEAUFORT
COUNTY SOUTH TO THE ALTAMAHA LATE THIS EVENING AND WE MAY HAVE TO
EXTEND THE FLASH FLOOD WATCH FOR THESE COUNTIES IF THIS COMES TO
FRUITION. BY DAYBREAK WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE
SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE INTO THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV.
MVFR OR LOWER CONDITIONS ARE LIKELY AS A RESULT...WITH HEAVY
RAINS AND GUSTY WINDS ALSO A CONCERN.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR SOME LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC...SO NO REASON TO DEVIATE FROM THE
EARLIER ISSUANCE OF THE FLASH FLOOD WATCH.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 162115
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
515 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH THIS EVENING...WATER VAPOR SATELLITE IMAGES SHOWING A
COUPLE OF MID LEVEL IMPULSES HEADING OUR WAY FROM UPSTREAM. ONE IS
OVER SOUTHERN GA AND THE SECOND IS A STRUNG OUT BUT PRONOUNCED
VORT LOBE ENTERING THE UPSTATE OF SC AND INTO NORTHERN GA. THESE
FEATURES WILL IMPACT THE AREA INTO THIS EVENING...AND THAT PLUS
UPPER DIFLUENCE ASSOCIATED WITH THE RIGHT REAR QUAD OF AN 250 MB
JET WILL SUPPLY THE NECESSARY FORCING FOR ASCENT. MEANWHILE THERE
IS STILL AN ABUNDANCE OF MOISTURE...UP ALMOST AT 2 STANDARD
DEVIATIONS ABOVE NORMAL. STEERING FLOW IS A LITTLE MORE NOTICEABLE
THAN RECENT DAYS...BUT STILL SLOW ENOUGH TO SUPPORT LIMITED
MOVEMENT TO OUR SHOWERS AND T-STORMS. PLUS THE CONVECTION WILL BE
STEERED TOWARD THE COAST WITH THE WEST/NW FLOW AND WILL BUMP UP
AGAINST THE PINNED SEA BREEZE...WHICH IMPLIES THAT A PILING UP OF
RAINFALL CAN OCCUR AS IT HAS NOWHERE FURTHER EAST OR SE TO
GO...STUCK AT THE SEA BREEZE BOUNDARY. WE ARE STILL HITTING THE
COASTAL ZONES OF SC AND AREAS SOUTH OF I-16 IN SE GA WITH THE
FLASH FLOOD WATCH THROUGH 8 PM...AND IT/S IN THESE AREAS THAT HAVE
THE HIGHEST POPS IN THE 60-80 PERCENT RANGE. FURTHER WEST AND NW
WE/LL RELY ON BOUNDARY INTERACTIONS TO POP ANY CONVECTION...AND
POPS ARE HELD TO 30-40 PERCENT DURING THE SECOND HALF OF THE
AFTERNOON.

ALSO OF NOTE...THERE IS A TAD BIT DRIER AND COLDER AIR IN THE MID
LEVELS AND MORE MOVEMENT IN THE TROPOSPHERE THAN OF LATE.
MODIFIED 12Z SOUNDINGS AND RECENT SPC MESO-ANALYSIS HAS SOME
DECENT THERMODYNAMICS....PERHAPS SUPPORTIVE A FEW STRONGER OR
EVEN MARGINALLY SEVERE STORMS WHERE THE BOUNDARY
INTERACTIONS...MERGERS AND/OR COLLISIONS OCCUR. THIS IS A LOW END
PROBABILITY...BUT WORTHY OF TALKING ABOUT WITH FREQUENT LIGHTNING
AND STRONG DOWNBURSTS OF WIND POSSIBLE IN A COUPLE OF THE TALLER
STORMS.

FOR TONIGHT...CONVECTION WILL BEGIN TO WANE DURING THE LATE
EVENING AS CINH REDEVELOPS AND THE TYPICAL NOCTURNAL
COOLING/STABILIZATION TAKES PLACE. HOWEVER...GIVEN NUMEROUS
BOUNDARY INTERACTIONS THAT WILL CONTINUE WE HAVE HELD ONTO
ISOLATED POPS FAR INLAND AND SCATTERED POPS FURTHER SOUTH AND EAST
THROUGH AT LEAST 03-05Z. THE HIGH RESOLUTION MODEL GUIDANCE IS
INDICATING THAT CONVECTION WILL ATTEMPT TO MERGE FROM NEAR BEAUFORT
COUNTY SOUTH TO THE ALTAMAHA LATE THIS EVENING AND WE MAY HAVE TO
EXTEND THE FLASH FLOOD WATCH FOR THESE COUNTIES IF THIS COMES TO
FRUITION. BY DAYBREAK WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE
SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE INTO THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV.
MVFR OR LOWER CONDITIONS ARE LIKELY AS A RESULT...WITH HEAVY
RAINS AND GUSTY WINDS ALSO A CONCERN.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR SOME LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC...SO NO REASON TO DEVIATE FROM THE
EARLIER ISSUANCE OF THE FLASH FLOOD WATCH.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 162002
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
402 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH THIS EVENING...WATER VAPOR SATELLITE IMAGES SHOWING A
COUPLE OF MID LEVEL IMPULSES HEADING OUR WAY FROM UPSTREAM. ONE IS
OVER SOUTHERN GA AND THE SECOND IS A STRUNG OUT BUT PRONOUNCED
VORT LOBE ENTERING THE UPSTATE OF SC AND INTO NORTHERN GA. THESE
FEATURES WILL IMPACT THE AREA INTO THIS EVENING...AND THAT PLUS
UPPER DIFLUENCE ASSOCIATED WITH THE RIGHT REAR QUAD OF AN 250 MB
JET WILL SUPPLY THE NECESSARY FORCING FOR ASCENT. MEANWHILE THERE
IS STILL AN ABUNDANCE OF MOISTURE...UP ALMOST AT 2 STANDARD
DEVIATIONS ABOVE NORMAL. STEERING FLOW IS A LITTLE MORE NOTICEABLE
THAN RECENT DAYS...BUT STILL SLOW ENOUGH TO SUPPORT LIMITED
MOVEMENT TO OUR SHOWERS AND T-STORMS. PLUS THE CONVECTION WILL BE
STEERED TOWARD THE COAST WITH THE WEST/NW FLOW AND WILL BUMP UP
AGAINST THE PINNED SEA BREEZE...WHICH IMPLIES THAT A PILING UP OF
RAINFALL CAN OCCUR AS IT HAS NOWHERE FURTHER EAST OR SE TO
GO...STUCK AT THE SEA BREEZE BOUNDARY. WE ARE STILL HITTING THE
COASTAL ZONES OF SC AND AREAS SOUTH OF I-16 IN SE GA WITH THE
FLASH FLOOD WATCH THROUGH 8 PM...AND IT/S IN THESE AREAS THAT HAVE
THE HIGHEST POPS IN THE 60-70 PERCENT RANGE. FURTHER WEST AND NW
WE/LL RELY ON BOUNDARY INTERACTIONS TO POP ANY CONVECTION...AND
POPS ARE HELD TO 30-40 PERCENT DURING THE SECOND HALF OF THE
AFTERNOON.

ALSO OF NOTE...THERE IS A TAD BIT DRIER AND COLDER AIR IN THE MID
LEVELS AND MORE MOVEMENT IN THE TROPOSPHERE THAN OF LATE.
MODIFIED 12Z SOUNDINGS AND RECENT SPC MESO-ANALYSIS HAS SOME
DECENT THERMODYNAMICS....PERHAPS SUPPORTIVE A FEW STRONGER OR
EVEN MARGINALLY SEVERE STORMS WHERE THE BOUNDARY
INTERACTIONS...MERGERS AND/OR COLLISIONS OCCUR. THIS IS A LOW END
PROBABILITY...BUT WORTHY OF TALKING ABOUT WITH FREQUENT LIGHTNING
AND STRONG DOWNBURSTS OF WIND POSSIBLE IN A COUPLE OF THE TALLER
STORMS.

FOR TONIGHT...CONVECTION WILL BEGIN TO WANE DURING THE LATE
EVENING AS CINH REDEVELOPS AND THE TYPICAL NOCTURNAL
COOLING/STABILIZATION TAKES PLACE. HOWEVER...GIVEN NUMEROUS
BOUNDARY INTERACTIONS THAT WILL CONTINUE WE HAVE HELD ONTO
ISOLATED POPS FAR INLAND AND SCATTERED POPS FURTHER SOUTH AND EAST
THROUGH AT LEAST 03-05Z. THE HIGH RESOLUTION MODEL GUIDANCE IS
INDICATING THAT CONVECTION WILL ATTEMPT TO MERGE FROM NEAR BEAUFORT
COUNTY SOUTH TO THE ALTAMAHA LATE THIS EVENING AND WE MAY HAVE TO
EXTEND THE FLASH FLOOD WATCH FOR THESE COUNTIES IF THIS COMES TO
FRUITION. BY DAYBREAK WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE
SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE INTO THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV. MOST
LIKELY TIME FRAME IS FROM 20-23Z AT KCHS AND FROM 21-24Z AT KSAV.
MVFR OR LOWER CONDITIONS ARE POSSIBLE AS A RESULT...WITH HEAVY
RAINS AND GUSTY WINDS ALSO A CONCERN.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR SOME LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC...SO NO REASON TO DEVIATE FROM THE
EARLIER ISSUANCE OF THE FLASH FLOOD WATCH.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 162002
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
402 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A TROUGH WILL MOVE INTO AND THROUGH THE AREA TONIGHT....FOLLOWED
BY A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
TONIGHT AND PUSHES THROUGH THE REGION LATE WEDNESDAY. AN INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT
INTO THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH THIS EVENING...WATER VAPOR SATELLITE IMAGES SHOWING A
COUPLE OF MID LEVEL IMPULSES HEADING OUR WAY FROM UPSTREAM. ONE IS
OVER SOUTHERN GA AND THE SECOND IS A STRUNG OUT BUT PRONOUNCED
VORT LOBE ENTERING THE UPSTATE OF SC AND INTO NORTHERN GA. THESE
FEATURES WILL IMPACT THE AREA INTO THIS EVENING...AND THAT PLUS
UPPER DIFLUENCE ASSOCIATED WITH THE RIGHT REAR QUAD OF AN 250 MB
JET WILL SUPPLY THE NECESSARY FORCING FOR ASCENT. MEANWHILE THERE
IS STILL AN ABUNDANCE OF MOISTURE...UP ALMOST AT 2 STANDARD
DEVIATIONS ABOVE NORMAL. STEERING FLOW IS A LITTLE MORE NOTICEABLE
THAN RECENT DAYS...BUT STILL SLOW ENOUGH TO SUPPORT LIMITED
MOVEMENT TO OUR SHOWERS AND T-STORMS. PLUS THE CONVECTION WILL BE
STEERED TOWARD THE COAST WITH THE WEST/NW FLOW AND WILL BUMP UP
AGAINST THE PINNED SEA BREEZE...WHICH IMPLIES THAT A PILING UP OF
RAINFALL CAN OCCUR AS IT HAS NOWHERE FURTHER EAST OR SE TO
GO...STUCK AT THE SEA BREEZE BOUNDARY. WE ARE STILL HITTING THE
COASTAL ZONES OF SC AND AREAS SOUTH OF I-16 IN SE GA WITH THE
FLASH FLOOD WATCH THROUGH 8 PM...AND IT/S IN THESE AREAS THAT HAVE
THE HIGHEST POPS IN THE 60-70 PERCENT RANGE. FURTHER WEST AND NW
WE/LL RELY ON BOUNDARY INTERACTIONS TO POP ANY CONVECTION...AND
POPS ARE HELD TO 30-40 PERCENT DURING THE SECOND HALF OF THE
AFTERNOON.

ALSO OF NOTE...THERE IS A TAD BIT DRIER AND COLDER AIR IN THE MID
LEVELS AND MORE MOVEMENT IN THE TROPOSPHERE THAN OF LATE.
MODIFIED 12Z SOUNDINGS AND RECENT SPC MESO-ANALYSIS HAS SOME
DECENT THERMODYNAMICS....PERHAPS SUPPORTIVE A FEW STRONGER OR
EVEN MARGINALLY SEVERE STORMS WHERE THE BOUNDARY
INTERACTIONS...MERGERS AND/OR COLLISIONS OCCUR. THIS IS A LOW END
PROBABILITY...BUT WORTHY OF TALKING ABOUT WITH FREQUENT LIGHTNING
AND STRONG DOWNBURSTS OF WIND POSSIBLE IN A COUPLE OF THE TALLER
STORMS.

FOR TONIGHT...CONVECTION WILL BEGIN TO WANE DURING THE LATE
EVENING AS CINH REDEVELOPS AND THE TYPICAL NOCTURNAL
COOLING/STABILIZATION TAKES PLACE. HOWEVER...GIVEN NUMEROUS
BOUNDARY INTERACTIONS THAT WILL CONTINUE WE HAVE HELD ONTO
ISOLATED POPS FAR INLAND AND SCATTERED POPS FURTHER SOUTH AND EAST
THROUGH AT LEAST 03-05Z. THE HIGH RESOLUTION MODEL GUIDANCE IS
INDICATING THAT CONVECTION WILL ATTEMPT TO MERGE FROM NEAR BEAUFORT
COUNTY SOUTH TO THE ALTAMAHA LATE THIS EVENING AND WE MAY HAVE TO
EXTEND THE FLASH FLOOD WATCH FOR THESE COUNTIES IF THIS COMES TO
FRUITION. BY DAYBREAK WEDNESDAY WE LOOK FOR ALL CONVECTION TO HAVE
SHIFTED OFFSHORE.

OF ADDITIONAL CONCERN TONIGHT IS THE POTENTIAL FOR A RETURN OF FOG
AND LOW STRATUS WITH A FAVORABLE 1-2C INVERSION TO SET UP OFF THE
DECK. GIVEN THE COPIOUS AMOUNTS OF RAINFALL IN RECENT DAYS AND
THAT FROM EARLIER TODAY...WITH LITTLE TO NO WINDS AND A SMIDGEN OF
DRIER AIR ALOFT SHIFTING IN...CONDITIONS AGAIN APPEAR FAVORABLE
FOR AREAS OF FOG TO OCCUR AFTER 2 OR 3 AM...EVEN DOWN TO THE COAST
WITH AN OFFSHORE FLOW DEVELOPING AND CONDENSATION PRESSURE DEFICITS
FALL TO UNDER 10 OR 20 MB. OUTSIDE RISK OF DENSE FOG IN LOCATIONS
WHERE THE HEAVIEST RAINS HAVE OCCURRED.

THE TEMP CURVE HAS BECOME INTERRUPTED IN AND NEAR CONVECTION AND
WE HAVE ATTEMPTED OUR BEST TO SHOW THIS IN THE HOURLY GRIDS. AS
COVERAGE/INTENSITY OF CONVECTION WINDS DOWN LATER THIS EVENING THE
TREND WILL BE FOR A SLOW BUT STEADY FALL TO TEMPS. DUE TO THE
PASSAGE OF A WEAK SURFACE TROUGH OVERNIGHT...A TAD COOLER AIR WILL
FILTER IN AS THE PLANETARY BOUNDARY LAYER FLOW VEERS AROUND TO THE
NW AND NORTH. THUS WE SHOULD BE ABLE TO ACHIEVE UPPER 60S INTO OUR
NW HALF OF THE CWFA BY MORNING...WITH LOWER 70S CLOSER TO THE
COAST AND A FEW MID 70S ON THE BARRIER ISLANDS.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A MID LVL TROUGH OF LOW PRESSURE WILL BEGIN SLIDING
OFF THE EASTERN SEABOARD BY DAYBREAK...SPAWNING AN AREA OF LOW
PRESSURE ALONG AN EAST-WEST EXTENDING SFC COLD FRONT THAT
GRADUALLY SHIFTS THROUGH THE ENTIRE AREA BY WEDNESDAY EVENING. THE
FRONT WILL LIKELY SLOW IN PROGRESSION WHILE ENCOUNTERING AN
AFTERNOON SEABREEZE IN SOUTHEAST GEORGIA...BEFORE SHIFTING FURTHER
SOUTH AND/OR OFFSHORE THROUGH WEDNESDAY EVENING. AMPLE MOISTURE
ALONG AND AHEAD OF THE FRONT SHOULD SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY AFTERNOON...WITH BEST CHANCES
OCCURRING WHERE THE FRONT AND SEABREEZE COLLIDE. A FEW SHOWERS
AND/OR ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE INTO LATE
EVENING AND EARLY OVERNIGHT HOURS AS SOME MOISTURE CONTINUES TO
LINGER BEHIND THE FRONT. ACTIVITY SHOULD THEN DIMINISH THEREAFTER
AS DRYER AIR ASSOCIATED WITH HIGH PRESSURE BUILDS FROM THE
NORTH/NORTHWEST.

LATEST 1000-850 THICKNESS VALUES SUPPORT ALONG WITH A DOWNSLOPING
WIND COMPONENT OFF THE SFC SUPPORT OVERALL HIGH TEMPS IN THE
MID/UPPER 80S WEDNESDAY AFTERNOON. OVERNIGHT LOW TEMPS SHOULD BE
SLIGHTLY COOLER THAN PREVIOUS DAYS AS HIGH PRESSURE BUILDS FROM THE
NORTH LATE...IN THE MID 60S AWAY FROM THE COAST.

THURSDAY AND FRIDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND
NORTHWEST THROUGH EARLY THIS WEEKEND...RESULTING IN DRYER CONDITIONS
ON THURSDAY AS THE FLOW REMAINS MAINLY OFFSHORE. WE COULD SEE AN
ISOLATED SHOWER AND/OR THUNDERSTORMS DEVELOP ALONG THE COAST LATE AS
SFC FLOW BECOMES MORE NORTH/NORTHEAST IN RESPONSE TO THE CENTER OF
HIGH PRESSURE SHIFTING OVER THE NORTHEASTERN UNITED STATES.
HOWEVER...ACTIVITY WILL LIKELY REMAIN CONFINED TO COASTAL LOCATIONS.
BY FRIDAY...A STRONGER NORTHEAST FLOW WILL SET UP ALONG THE
SOUTHEAST COAST AS HIGH PRESSURE BECOMES CENTERED OFF THE NORTHEAST
COAST. THIS SHOULD SUPPORT SLIGHTLY HIGHER CHANCES OF PRECIP AS
MOISTURE BEGINS TO RETURN OFF THE ATLANTIC. EXPECT MOST ACTIVITY TO
REMAIN ALONG THE COAST INITIALLY BEFORE GRADUALLY SHIFTING INLAND
WITH AN AFTERNOON SEABREEZE. HAVE MAINTAINED LOW-END CHANCE POPS
FRIDAY ALONG THE COAST AND SLIGHT CHANCE POPS FURTHER INLAND WITH
THE AFTERNOON SEABREEZE.

OVERALL HIGH TEMPS WILL BE COOLER AS HIGH PRESSURE EXTENDS OVER THE
AREA FROM THE NORTH. EXPECT AFTERNOON HIGHS IN THE LOW/MID 80S ON
THURSDAY AND LOW 80S ON FRIDAY. THURSDAY NIGHT TEMPS WILL ALSO REFLECT
COOLER CONDITIONS...WITH LOWS IN THE LOW/MID 60S AWAY FROM THE
COAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE INTO THIS
EVENING...ALLOWING FOR DIRECT IMPACTS AT BOTH KCHS AND KSAV. MOST
LIKELY TIME FRAME IS FROM 20-23Z AT KCHS AND FROM 21-24Z AT KSAV.
MVFR OR LOWER CONDITIONS ARE POSSIBLE AS A RESULT...WITH HEAVY
RAINS AND GUSTY WINDS ALSO A CONCERN.

ACTIVITY WILL WANE LATE THIS EVENING...AND GIVEN WET
GROUNDS...LITTLE TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO
FORM WE LOOK FOR SOME LOW STRATUS AND/OR FOG LATE TONIGHT INTO
WEDNESDAY MORNING. MVFR OR LOWER CONDITIONS ARE AGAIN A
POSSIBILITY...BEFORE VFR CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...OUTSIDE OF SHRA AND/OR TSRA...FLIGHT
RESTRICTIONS WILL BE POSSIBLE EACH MORNING WITH FOG AND/OR LOW
STRATUS SHIFTING ONSHORE.

&&

.MARINE...
TONIGHT...WE HAVE SEEN A LITTLE SWELL ENERGY FROM DISTANT MAJOR
HURRICANE EDOUARD TRICKLING INTO OUR COASTAL WATERS...AND
ADDITIONAL SWELL ENERGY IS TO ARRIVE AS TIME PROGRESSES. THE BULK
OF THE WAVE SPECTRUM WILL BE COMPRISED OF THESE CONDITIONS...WHICH
AVERAGES 2 OR 3 FT EARLY TONIGHT...BUILDING ANOTHER FOOT
LATE...EXCEPT CLIMBING UP TO SOME 5 FOOTERS ON THE OUTER GA
WATERS BY SUNRISE WEDNESDAY. MEANWHILE...WITH A WEAK PRESSURE
PATTERN OUR WIND FIELDS WILL BE DRIVEN BY A LIGHT SE BREEZE
CIRCULATION AND SCATTERED TO NUMEROUS CONVECTION INTO THIS
EVENING. THEN AS THIS ACTIVITY STARTS TO FADE DURING THE LATE
EVENING AND OVERNIGHT...AND A WEAK SURFACE TROUGH DROPS THROUGH
FROM THE NORTH/NW...LAND BREEZE CIRCULATIONS WILL FORM. THIS
ALLOWS FOR VEERING WINDS TO THE SW AND WEST BY MIDNIGHT...THEN
AROUND TO THE NW OR NORTH LATE. OUTSIDE OF THE STRONGER CONVECTION
WINDS WILL OBTAIN NO MORE THAN ABOUT 10 KT. HOWEVER...MARINERS ARE
ADVISED THAT THE STRONGER STORMS EARLY TONIGHT WILL PRODUCE GUSTY
WINDS UP NEAR 30 OR 35 KT...HEAVY RAINS LOWERING VISIBILITIES TO
UNDER 1 NM AND FREQUENT LIGHTNING STRIKES. BE SAFE ON THE COASTAL
WATERS.

WEDNESDAY THROUGH SUNDAY...LIGHT WINDS WILL INCREASE AND BECOME
NORTH/NORTHEAST BEHIND A COLD FRONT THAT SHIFTS OVER THE WATERS
WEDNESDAY THROUGH THURSDAY. SEAS WILL BE COMPRISED MAINLY OF LONG
PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND 2 TO
4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE. A STRONGER
NORTHEAST FLOW WILL THEN DEVELOP OVER THE WATERS ON FRIDAY AND
PERSIST INTO SATURDAY AS THE PRESSURE GRADIENT BECOMES ENHANCED
ALONG THE SOUTHERN EDGE OF HIGH PRESSURE CENTERED ALONG THE
NORTHEAST COAST. HOWEVER...WINDS/SEAS ARE EXPECTED TO REMAIN JUST
BELOW SMALL CRAFT ADVISORY CRITERIA AT THIS TIME. CONDITIONS
SHOULD MODERATE OVER THE WATERS WITHIN A TRANSITIONING PATTERN BY
SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL OCCUR
ALONG THE BEACHES WEDNESDAY INTO THURSDAY. DESPITE ONLY LIGHT
ONSHORE WINDS...2-3 FT SWELLS WITH PERIODS NEAR 14 SECONDS SUPPORT
AN ENHANCED PERIOD OF RIP CURRENTS ALONG THE SOUTH CAROLINA AND
GEORGIA BEACHES. A MODERATE RISK OF RIP CURRENTS IS THEREFORE
EXPECTED ALONG ALL BEACHES ON WEDNESDAY...AND POSSIBLY THURSDAY.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING AS THE CONVECTION RUNS INTO THE SEA
BREEZE BOUNDARY THAT IS STRUGGLING TO MOVE INLAND.

WITH FAVORABLE UPPER JET DYNAMICS AND FORCING FROM SHORT
WAVES...ABUNDANT PWATS APPROACHING 2 STANDARD DEVIATIONS ABOVE
NORMAL FOR MID-SEPTEMBER AND STORM MOTIONS LESS THAN 10 KT WE LOOK
FOR HOURLY RAINFALL RATES OF 2-3 INCHES...AND 6 HOUR AMOUNTS OF AS
MUCH AS 4 OR 5 INCHES. THESE ARE NEAR OR GREATER THAN THE FLASH
FLOOD GUIDANCE FROM THE SERFC...SO NO REASON TO DEVIATE FROM THE
EARLIER ISSUANCE OF THE FLASH FLOOD WATCH.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 161726
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
126 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND
PUSH THROUGH THE REGION LATE WEDNESDAY. AN INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT INTO THE
WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A BROAD LARGE SCALE TROUGH WILL PREVAIL ACROSS THE EASTERN HALF OF
THE NATION TODAY AS SHORT WAVE ENERGY CONTINUES TO FEED INTO THE
TROUGH WITHIN THE WEST/NW FLOW ALOFT. OUR SURFACE PATTERN IS WEAK
BUT DEFINED BY DEVELOPING PRE-FRONTAL TROUGH ALIGNED NE-SW THAT
LOOKS TO STAY OFF TO OUR NW THROUGH DARK. THIS SCENARIO SETS THE
STAGE FOR MORE MORE FAIRLY ACTIVE CONVECTIVE AFTERNOON.

WATER VAPOR SATELLITE IMAGES SHOWING A COUPLE OF MID LEVEL
IMPULSES HEADING OUR WAY FROM UPSTREAM. ONE IS OVER SOUTHERN GA
AND THE SECOND IS A STRUNG OUT BUT PRONOUNCED VORT LOBE ENTERING
THE UPSTATE OF SC AND INTO NORTHERN GA. THESE FEATURES WILL IMPACT
THE AREA THIS AFTERNOON OR EVENING...AND THAT PLUS UPPER DIFLUENCE
ASSOCIATED WITH THE RIGHT REAR QUAD OF AN 250 MB JET WILL SUPPLY
THE NECESSARY FORCING FOR ASCENT. MEANWHILE THERE IS STILL AN
ABUNDANCE OF MOISTURE...UP ALMOST AT 2 STANDARD DEVIATIONS ABOVE
NORMAL. STEERING FLOW IS A LITTLE MORE NOTICEABLE THAN RECENT
DAYS...BUT STILL SLOW ENOUGH TO SUPPORT LIMITED MOVEMENT TO OUR
SHOWERS AND T-STORMS. PLUS THE CONVECTION WILL BE STEERED TOWARD
THE COAST WITH THE WEST/NW FLOW AND WILL BUMP UP AGAINST THE
PINNED SEA BREEZE /ONCE IT ACTUALLY DEVELOPS/...WHICH IMPLIES THAT A
PILING UP OF RAINFALL CAN OCCUR AS IT HAS NOWHERE FURTHER EAST OR
SE TO GO...STUCK AT THE SEA BREEZE BOUNDARY. WE ARE STILL HITTING
THE COASTAL ZONES OF SC AND AREAS SOUTH OF I-16 IN SE GA WITH THE
FLASH FLOOD WATCH...AND IT/S IN THESE AREAS THAT HAVE THE HIGHEST
POPS IN THE 60-70 PERCENT RANGE.

COVERAGE OF SHOWERS AND T-STORMS WILL CONTINUE TO INCREASE THIS
AFTERNOON OVER OUR NORTHERN AND EASTERN FIRST WHERE WE HAVE SEEN
SOME INSOLATION FROM EARLIER IN THE DAY. FURTHER SOUTH THE
INSOLATION HAS BEEN SLOWER IN ARRIVING AND CINH HAS BEEN HOLDING
ON...THUS DELAYING THE ONSET OF CONVECTION. BUT THAT AREA WILL
ALSO GET IN ON THE ACTION BY 3 OR 4 PM. RAINFALL IN OUR EASTERN
AND SOUTHERN ZONES WILL EXPERIENCE RAINFALL HEAVY AT TIMES. THE
INCREASE IN SHOWERS AND T-STORMS WILL BE THE RESULT OF THE
PERTURBATIONS ALOFT...THE PINNED SEA BREEZE...DIFFERENTIAL HEATING
BOUNDARIES FROM MORNING FOG/STRATUS AND OUTFLOW BOUNDARY
INTERACTIONS OCCUR. FURTHER WEST AND NW WE/LL RELY ON BOUNDARY
INTERACTIONS TO POP ANY CONVECTION...AND POPS ARE HELD TO 30-40
PERCENT DURING THE SECOND HALF OF THE AFTERNOON.

ALSO OF NOTE...THERE IS A TAD BIT DRIER AND COLDER AIR IN THE MID
LEVELS AND MORE MOVEMENT IN THE TROPOSPHERE THAN OF LATE.
MODIFIED 12Z SOUNDINGS AND RECENT SPC MESO-ANALYSIS HAS SOME
DECENT THERMODYNAMICS....PERHAPS SUPPORTIVE A FEW STRONGER OR
EVEN MARGINALLY SEVERE STORMS WHERE THE BOUNDARY
INTERACTIONS...MERGERS AND/OR COLLISIONS OCCUR. THIS IS A LOW END
PROBABILITY...BUT WORTHY OF TALKING ABOUT WITH FREQUENT LIGHTNING
AND STRONG DOWNBURSTS OF WIND POSSIBLE IN A COUPLE OF THE TALLER
STORMS.

DOWNSLOPE FLOW OFF THE MOUNTAINS AND WARM ADVECTION IN ADVANCE OF
THE SURFACE TROUGH AND UPSTREAM COLD FRONT WILL NEGATE THE EFFECTS
OF EXTENSIVE CLOUD COVER TO WARM TEMPS YET AGAIN ABOVE
CLIMATOLOGICAL NORMS. THERE IS EVEN SOME POCKETS OF DECENT
INSOLATION BETWEEN LARGE BREAKS IN THE CLOUD COVER THROWN INTO THE
MIX. WE MIGHT BE A LITTLE CONSERVATIVE ON ACTUAL HIGHS...BUT WE
HAVE TWEAKED TEMPS A DEGREE OR 2...MAINLY INTO THE UPPER 80S OR
NEAR 90 AWAY FROM THE IMMEDIATE COAST. PENDING TRENDS WE MIGHT
EVEN NEED TO GO A TAD HIGHER. KEEP IN MIND THAT ONCE CONVECTION
INITIATES AND COVERAGE SPREADS OUT THAT OUR DIURNAL TEMP CURVE
WILL NEED BIG ADJUSTMENTS. WE HAVE LEANED THIS WAY IN OUR HOURLY
TEMP FORECAST...BUT NO DOUBT FUTURE AMENDMENTS WILL BE REQUIRED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...CONVECTION WILL QUICKLY WANE THIS EVENING WITH THE LOSS
OF INSOLATION. THE RISK FOR RAINFALL WILL GRADUALLY SHIFT OFFSHORE
CLOSER TO THE WESTERN WALL OF THE GULF STREAM AS A COLD FRONT
QUICKLY APPROACHES FROM THE NORTH. THE FRONT LOOKS TO REMAIN NORTH
AND NORTHWEST OF THE AREA THROUGH SUNRISE WEDNESDAY. SOME CLEARING
WILL LIKELY TAKE HOLD EARLY WEDNESDAY...ESPECIALLY ACROSS THE
WESTERN ZONES. WILL HAVE TO WATCH FOR POSSIBLE LOW STRATUS AND FOG
ONCE AGAIN GIVEN THE WET GROUNDS AND THE LIGHT WIND FIELDS THAT
WILL BE IN PLACE.

WEDNESDAY...THE SURFACE TROUGH WILL HAVE SHIFTED OFF THE SOUTHEAST
COASTLINE BY DAYBREAK...JUST DOWNSTREAM OF A SERIES OF SHORTWAVES
EMBEDDED WITHIN THE BASE OF A SHARPENING UPPER TROUGH AXIS.
PROGRESSION OF A STRONG COLD FRONT THROUGH THE FORECAST AREA
WILL LIKELY BE DELAYED UNTIL THE EVENING OR NIGHTTIME
PERIOD...WHEN A MORE DISTINCT AIR MASS CHANGE IS EVIDENT ALONG THE
LEADING EDGE OF STRONG HIGH PRESSURE BUILDING FROM THE
WEST/NORTHWEST. THE RIBBON OF DEEP LAYER MOISTURE RESPONSIBLE FOR
SEVERAL DAYS OF HEAVY RAIN EARLIER IN THE WEEK WILL HAVE MOVED TO
THE EAST/SOUTHEAST WITH THE SURFACE TROUGH. HOWEVER...THERE
APPEARS SUFFICIENT RESIDUAL MOISTURE TO SUPPORT SCATTERED
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON TIME
FRAME...ESPECIALLY AS SHORTWAVE ENERGY TRACKS THROUGH THE REGION
AND SEABREEZE DEVELOPMENT PROVIDES SOME FORCING/CONVERGENCE.
ISOLATED SHOWERS/THUNDERSTORMS COULD ACCOMPANY THE FRONT TOWARD
THE COASTLINE THROUGH MIDNIGHT...AND THEN EXPECT BEST RAIN CHANCES
TO SHIFT OVER THE MARINE ZONES DURING THE PRE-DAWN HOURS. HIGH
TEMPERATURES WILL ONCE AGAIN RISE ABOVE SEASONAL NORMALS WITHIN
DOWNSLOPE FLOW AND PRE-FRONTAL COMPRESSION...PEAKING IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES WILL
STILL BE A DEGREE OR TWO ABOVE NORMAL...YET TREND COOLER THAN
PREVIOUS NIGHTS BY FALLING INTO THE MID TO UPPER 60S.

THURSDAY AND FRIDAY...NORTHEAST FLOW DEVELOPING IN THE WAKE OF THE
FRONT AND WITHIN BUILDING HIGH PRESSURE FROM THE NORTH WILL
SUPPORT A NOTABLE COOLING TREND LATE IN THE WEEK. HIGH
TEMPERATURES ON THURSDAY WILL ONLY PEAK IN THE LOW TO MID
80S...WHILE ONLY RISING TO THE LOWER 80S FOR FRIDAY AFTERNOON.
NIGHTTIME LOW TEMPERATURES WILL ALSO REFLECT THE AIR MASS
CHANGE...AS LOWER DEWPOINTS/DRIER AIR ALLOW TEMPERATURES TO FALL
INTO THE LOW TO MID 60S. AS THE CENTER OF THE SURFACE HIGH TRACKS
FROM THE GREAT LAKES REGION THURSDAY AND INTO THE NEW ENGLAND
STATES FRIDAY...THE INLAND WEDGE WILL AMPLIFY DOWN THE
APPALACHIANS AND A COASTAL TROUGH WILL TAKE SHAPE ON THE SOUTHERN
COASTLINE. THIS PATTERN COULD ALLOW A DISTINCT GRADIENT IN
PRECIPITATION POTENTIAL BETWEEN THE DRIER INLAND AREAS AND COASTAL
COUNTIES NEAR CONVERGENCE ALONG THE TROUGH. RAIN COVERAGE WILL
STILL BE CONSIDERABLY LOWER THAN EARLIER IN THE WEEK FOR ALL
LOCATIONS...AND WILL ADVERTISE JUST ISOLATED SHOWERS/THUNDERSTORMS
INLAND AND SCATTERED ALONG THE COAST...MAINLY DURING THE AFTERNOON
PERIOD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
COVERAGE OF SHRA AND TSRA WILL BE ON THE RISE DURING THE MID AND
LATE AFTERNOON...ALLOWING FOR POSSIBLE DIRECT IMPACTS AT BOTH KCHS
AND KSAV. MOST LIKELY TIME FRAME IS FROM 20-23Z AT KCHS AND FROM
21-24Z AT KSAV. MVFR OR LOWER CONDITIONS ARE POSSIBLE AS A
RESULT...WITH HEAVY RAINS AND GUSTY WINDS A CONCERN.

ACTIVITY WILL WANE THIS EVENING...AND GIVEN WET GROUNDS...LITTLE
TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO FORM WE LOOK FOR
SOME LOW STRATUS AND/OR FOG LATE TONIGHT INTO WEDNESDAY MORNING.
MVFR OR LOWER CONDITIONS ARE AGAIN A POSSIBILITY...BEFORE VFR
CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY...A FAIRLY NEBULOUS PRESSURE PATTERN SETS UP UNDERNEATH
WEAK HIGH PRESSURE AND IN ADVANCE OF OUR NEXT UPSTREAM COLD FRONT.
THIS WILL ALLOW FOR LIGHT WEST/NW TO GIVE WAY TO A RESULTANT
SOUTH/SW SEA BREEZE CIRCULATION DURING THE MID AND LATE AFTERNOON.
ALTHOUGH AT TIMES THE WIND FIELDS WILL BECOME SOMEWHAT MUDDLED IN
CHARLESTON HARBOR AND THE NEARBY COASTAL WATERS DUE TO CONVECTION.
WE/RE STARTING TO SEE A LITTLE SWELL ENERGY FROM DISTANT HURRICANE
EDOUARD APPROACHING OUR WATERS FROM THE EAST...BUT AVERAGE WAVE
HEIGHTS WILL BE HELD TO AROUND 2 FT THROUGHOUT THE DAY. MARINERS
ARE ALERTED TO A FEW STRONGER STORMS WHICH CAN PRODUCE FREQUENT
LIGHTNING...HEAVY RAINS AND GUSTY WINDS.

TONIGHT...LONG PERIOD SWELLS FROM HURRICANE EDOUARD WILL BEGIN TO
AFFECT THE WATERS WITH PERIODS OF 11-14 SECONDS. SEAS OF 1-2 FT
WILL BUILD TO 2-4 FT NEARSHORE WATERS AND 4-5 FT OFFSHORE WATERS.
ATTM IT APPEARS SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS...ALTHOUGH IT WILL BE CLOSE FOR THE GEORGIA OFFSHORE
WATERS.

WEDNESDAY AND THURSDAY...A COLD FRONT WILL PROGRESS INTO AND
THROUGH THE WATERS DURING THE MID WEEK PERIOD. LIGHT WINDS IN
ADVANCE OF THE FRONT WEDNESDAY WILL BECOME NORTH/NORTHEAST AND
INCREASE IN ITS WAKE BY THURSDAY. SEAS WILL BE COMPRISED MAINLY OF
LONG PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND
2 TO 4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS FAR OFFSHORE AND REMAINS FAIRLY
STATIONARY ALONG THE PERIPHERY OF AN INLAND WEDGE OF HIGH
PRESSURE. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE FOR
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...BEFORE
CONDITIONS MODERATE WITHIN A TRANSITIONING PATTERN BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL
ARRIVE AT THE BEACHES LATE THIS AFTERNOON AND CONTINUE INTO
THURSDAY. THERE DOES NOT APPEAR TO BE MUCH MORE THAN ABOUT 1 OR 2 FT
SWELL THAT MAKES IT TO THE BEACHES BY LATE AFTERNOON...SO THE RIP
CURRENT RISK WILL REMAIN IN THE LOW CATEGORY FOR TODAY. LARGER
SWELLS AROUND 3 FT WILL OCCUR WEDNESDAY INTO THURSDAY AND THIS
WILL LEAD TO AN ENHANCED RISK OF RIP CURRENTS. FOR FRIDAY THROUGH
SUNDAY SWELL FROM EDOUARD WILL DIMINISH...BUT STRONGER NE WINDS
WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK OF RIP CURRENTS
TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING IN PARTS
OF THE AREA. HIGH RESOLUTION MODELS ARE SHOWING A DISTINCT SIGNAL
THAT AN AREA OF HEAVY RAIN WILL SETUP IN THE AREA FROM SAVANNAH
SOUTH TO DARIEN AND OVER TO SPRINGFIELD AND GLENNVILLE FOR SEVERAL
HOURS THIS AFTERNOON ALONG A PINNED SEA BREEZE CIRCULATION.
ALTHOUGH STORM MOTIONS WILL BE FASTER THAN PREVIOUS DAYS...THE
POTENTIAL FOR NUMEROUS MESOSCALE BOUNDARY INTERACTIONS...STRONG
UPPER DIVERGENCE AND HIGH PWAT VALUES APPROACHING 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR MID SEPTEMBER SUGGEST THERE IS A HIGH
POTENTIAL FOR EXCESSIVE HOURLY RAINFALL RATES EXCEEDING 2-3
IN/HR...WHICH IS NEAR OR HIGHER THAN THE LATEST 1-HR FLASH FLOOD
GUIDANCE. IN ADDITION...SOME AREAS HAVE ALREADY SEEN IN EXCESS OF
6 INCHES OVER THE PAST FEW DAYS.

A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING TODAY. THE COASTAL SOUTH CAROLINA
ZONES HAVE BEEN INCLUDED IN THE WATCH MAINLY TO ACCOUNT FOR
POSSIBLE HEAVY RAIN FALLING AROUND HIGH TIDE THIS AFTERNOON.
SIMILAR TO THE PAST FEW DAYS...ISOLATED RAIN AMOUNTS IN EXCESS OF
4 OR EVEN 5 INCHES WILL BE POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 161726
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
126 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND
PUSH THROUGH THE REGION LATE WEDNESDAY. AN INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT INTO THE
WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A BROAD LARGE SCALE TROUGH WILL PREVAIL ACROSS THE EASTERN HALF OF
THE NATION TODAY AS SHORT WAVE ENERGY CONTINUES TO FEED INTO THE
TROUGH WITHIN THE WEST/NW FLOW ALOFT. OUR SURFACE PATTERN IS WEAK
BUT DEFINED BY DEVELOPING PRE-FRONTAL TROUGH ALIGNED NE-SW THAT
LOOKS TO STAY OFF TO OUR NW THROUGH DARK. THIS SCENARIO SETS THE
STAGE FOR MORE MORE FAIRLY ACTIVE CONVECTIVE AFTERNOON.

WATER VAPOR SATELLITE IMAGES SHOWING A COUPLE OF MID LEVEL
IMPULSES HEADING OUR WAY FROM UPSTREAM. ONE IS OVER SOUTHERN GA
AND THE SECOND IS A STRUNG OUT BUT PRONOUNCED VORT LOBE ENTERING
THE UPSTATE OF SC AND INTO NORTHERN GA. THESE FEATURES WILL IMPACT
THE AREA THIS AFTERNOON OR EVENING...AND THAT PLUS UPPER DIFLUENCE
ASSOCIATED WITH THE RIGHT REAR QUAD OF AN 250 MB JET WILL SUPPLY
THE NECESSARY FORCING FOR ASCENT. MEANWHILE THERE IS STILL AN
ABUNDANCE OF MOISTURE...UP ALMOST AT 2 STANDARD DEVIATIONS ABOVE
NORMAL. STEERING FLOW IS A LITTLE MORE NOTICEABLE THAN RECENT
DAYS...BUT STILL SLOW ENOUGH TO SUPPORT LIMITED MOVEMENT TO OUR
SHOWERS AND T-STORMS. PLUS THE CONVECTION WILL BE STEERED TOWARD
THE COAST WITH THE WEST/NW FLOW AND WILL BUMP UP AGAINST THE
PINNED SEA BREEZE /ONCE IT ACTUALLY DEVELOPS/...WHICH IMPLIES THAT A
PILING UP OF RAINFALL CAN OCCUR AS IT HAS NOWHERE FURTHER EAST OR
SE TO GO...STUCK AT THE SEA BREEZE BOUNDARY. WE ARE STILL HITTING
THE COASTAL ZONES OF SC AND AREAS SOUTH OF I-16 IN SE GA WITH THE
FLASH FLOOD WATCH...AND IT/S IN THESE AREAS THAT HAVE THE HIGHEST
POPS IN THE 60-70 PERCENT RANGE.

COVERAGE OF SHOWERS AND T-STORMS WILL CONTINUE TO INCREASE THIS
AFTERNOON OVER OUR NORTHERN AND EASTERN FIRST WHERE WE HAVE SEEN
SOME INSOLATION FROM EARLIER IN THE DAY. FURTHER SOUTH THE
INSOLATION HAS BEEN SLOWER IN ARRIVING AND CINH HAS BEEN HOLDING
ON...THUS DELAYING THE ONSET OF CONVECTION. BUT THAT AREA WILL
ALSO GET IN ON THE ACTION BY 3 OR 4 PM. RAINFALL IN OUR EASTERN
AND SOUTHERN ZONES WILL EXPERIENCE RAINFALL HEAVY AT TIMES. THE
INCREASE IN SHOWERS AND T-STORMS WILL BE THE RESULT OF THE
PERTURBATIONS ALOFT...THE PINNED SEA BREEZE...DIFFERENTIAL HEATING
BOUNDARIES FROM MORNING FOG/STRATUS AND OUTFLOW BOUNDARY
INTERACTIONS OCCUR. FURTHER WEST AND NW WE/LL RELY ON BOUNDARY
INTERACTIONS TO POP ANY CONVECTION...AND POPS ARE HELD TO 30-40
PERCENT DURING THE SECOND HALF OF THE AFTERNOON.

ALSO OF NOTE...THERE IS A TAD BIT DRIER AND COLDER AIR IN THE MID
LEVELS AND MORE MOVEMENT IN THE TROPOSPHERE THAN OF LATE.
MODIFIED 12Z SOUNDINGS AND RECENT SPC MESO-ANALYSIS HAS SOME
DECENT THERMODYNAMICS....PERHAPS SUPPORTIVE A FEW STRONGER OR
EVEN MARGINALLY SEVERE STORMS WHERE THE BOUNDARY
INTERACTIONS...MERGERS AND/OR COLLISIONS OCCUR. THIS IS A LOW END
PROBABILITY...BUT WORTHY OF TALKING ABOUT WITH FREQUENT LIGHTNING
AND STRONG DOWNBURSTS OF WIND POSSIBLE IN A COUPLE OF THE TALLER
STORMS.

DOWNSLOPE FLOW OFF THE MOUNTAINS AND WARM ADVECTION IN ADVANCE OF
THE SURFACE TROUGH AND UPSTREAM COLD FRONT WILL NEGATE THE EFFECTS
OF EXTENSIVE CLOUD COVER TO WARM TEMPS YET AGAIN ABOVE
CLIMATOLOGICAL NORMS. THERE IS EVEN SOME POCKETS OF DECENT
INSOLATION BETWEEN LARGE BREAKS IN THE CLOUD COVER THROWN INTO THE
MIX. WE MIGHT BE A LITTLE CONSERVATIVE ON ACTUAL HIGHS...BUT WE
HAVE TWEAKED TEMPS A DEGREE OR 2...MAINLY INTO THE UPPER 80S OR
NEAR 90 AWAY FROM THE IMMEDIATE COAST. PENDING TRENDS WE MIGHT
EVEN NEED TO GO A TAD HIGHER. KEEP IN MIND THAT ONCE CONVECTION
INITIATES AND COVERAGE SPREADS OUT THAT OUR DIURNAL TEMP CURVE
WILL NEED BIG ADJUSTMENTS. WE HAVE LEANED THIS WAY IN OUR HOURLY
TEMP FORECAST...BUT NO DOUBT FUTURE AMENDMENTS WILL BE REQUIRED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...CONVECTION WILL QUICKLY WANE THIS EVENING WITH THE LOSS
OF INSOLATION. THE RISK FOR RAINFALL WILL GRADUALLY SHIFT OFFSHORE
CLOSER TO THE WESTERN WALL OF THE GULF STREAM AS A COLD FRONT
QUICKLY APPROACHES FROM THE NORTH. THE FRONT LOOKS TO REMAIN NORTH
AND NORTHWEST OF THE AREA THROUGH SUNRISE WEDNESDAY. SOME CLEARING
WILL LIKELY TAKE HOLD EARLY WEDNESDAY...ESPECIALLY ACROSS THE
WESTERN ZONES. WILL HAVE TO WATCH FOR POSSIBLE LOW STRATUS AND FOG
ONCE AGAIN GIVEN THE WET GROUNDS AND THE LIGHT WIND FIELDS THAT
WILL BE IN PLACE.

WEDNESDAY...THE SURFACE TROUGH WILL HAVE SHIFTED OFF THE SOUTHEAST
COASTLINE BY DAYBREAK...JUST DOWNSTREAM OF A SERIES OF SHORTWAVES
EMBEDDED WITHIN THE BASE OF A SHARPENING UPPER TROUGH AXIS.
PROGRESSION OF A STRONG COLD FRONT THROUGH THE FORECAST AREA
WILL LIKELY BE DELAYED UNTIL THE EVENING OR NIGHTTIME
PERIOD...WHEN A MORE DISTINCT AIR MASS CHANGE IS EVIDENT ALONG THE
LEADING EDGE OF STRONG HIGH PRESSURE BUILDING FROM THE
WEST/NORTHWEST. THE RIBBON OF DEEP LAYER MOISTURE RESPONSIBLE FOR
SEVERAL DAYS OF HEAVY RAIN EARLIER IN THE WEEK WILL HAVE MOVED TO
THE EAST/SOUTHEAST WITH THE SURFACE TROUGH. HOWEVER...THERE
APPEARS SUFFICIENT RESIDUAL MOISTURE TO SUPPORT SCATTERED
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON TIME
FRAME...ESPECIALLY AS SHORTWAVE ENERGY TRACKS THROUGH THE REGION
AND SEABREEZE DEVELOPMENT PROVIDES SOME FORCING/CONVERGENCE.
ISOLATED SHOWERS/THUNDERSTORMS COULD ACCOMPANY THE FRONT TOWARD
THE COASTLINE THROUGH MIDNIGHT...AND THEN EXPECT BEST RAIN CHANCES
TO SHIFT OVER THE MARINE ZONES DURING THE PRE-DAWN HOURS. HIGH
TEMPERATURES WILL ONCE AGAIN RISE ABOVE SEASONAL NORMALS WITHIN
DOWNSLOPE FLOW AND PRE-FRONTAL COMPRESSION...PEAKING IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES WILL
STILL BE A DEGREE OR TWO ABOVE NORMAL...YET TREND COOLER THAN
PREVIOUS NIGHTS BY FALLING INTO THE MID TO UPPER 60S.

THURSDAY AND FRIDAY...NORTHEAST FLOW DEVELOPING IN THE WAKE OF THE
FRONT AND WITHIN BUILDING HIGH PRESSURE FROM THE NORTH WILL
SUPPORT A NOTABLE COOLING TREND LATE IN THE WEEK. HIGH
TEMPERATURES ON THURSDAY WILL ONLY PEAK IN THE LOW TO MID
80S...WHILE ONLY RISING TO THE LOWER 80S FOR FRIDAY AFTERNOON.
NIGHTTIME LOW TEMPERATURES WILL ALSO REFLECT THE AIR MASS
CHANGE...AS LOWER DEWPOINTS/DRIER AIR ALLOW TEMPERATURES TO FALL
INTO THE LOW TO MID 60S. AS THE CENTER OF THE SURFACE HIGH TRACKS
FROM THE GREAT LAKES REGION THURSDAY AND INTO THE NEW ENGLAND
STATES FRIDAY...THE INLAND WEDGE WILL AMPLIFY DOWN THE
APPALACHIANS AND A COASTAL TROUGH WILL TAKE SHAPE ON THE SOUTHERN
COASTLINE. THIS PATTERN COULD ALLOW A DISTINCT GRADIENT IN
PRECIPITATION POTENTIAL BETWEEN THE DRIER INLAND AREAS AND COASTAL
COUNTIES NEAR CONVERGENCE ALONG THE TROUGH. RAIN COVERAGE WILL
STILL BE CONSIDERABLY LOWER THAN EARLIER IN THE WEEK FOR ALL
LOCATIONS...AND WILL ADVERTISE JUST ISOLATED SHOWERS/THUNDERSTORMS
INLAND AND SCATTERED ALONG THE COAST...MAINLY DURING THE AFTERNOON
PERIOD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
COVERAGE OF SHRA AND TSRA WILL BE ON THE RISE DURING THE MID AND
LATE AFTERNOON...ALLOWING FOR POSSIBLE DIRECT IMPACTS AT BOTH KCHS
AND KSAV. MOST LIKELY TIME FRAME IS FROM 20-23Z AT KCHS AND FROM
21-24Z AT KSAV. MVFR OR LOWER CONDITIONS ARE POSSIBLE AS A
RESULT...WITH HEAVY RAINS AND GUSTY WINDS A CONCERN.

ACTIVITY WILL WANE THIS EVENING...AND GIVEN WET GROUNDS...LITTLE
TO NO WINDS AND A DECENT NOCTURNAL INVERSION TO FORM WE LOOK FOR
SOME LOW STRATUS AND/OR FOG LATE TONIGHT INTO WEDNESDAY MORNING.
MVFR OR LOWER CONDITIONS ARE AGAIN A POSSIBILITY...BEFORE VFR
CONDITIONS RETURN AFTER 13-14Z WEDNESDAY.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY...A FAIRLY NEBULOUS PRESSURE PATTERN SETS UP UNDERNEATH
WEAK HIGH PRESSURE AND IN ADVANCE OF OUR NEXT UPSTREAM COLD FRONT.
THIS WILL ALLOW FOR LIGHT WEST/NW TO GIVE WAY TO A RESULTANT
SOUTH/SW SEA BREEZE CIRCULATION DURING THE MID AND LATE AFTERNOON.
ALTHOUGH AT TIMES THE WIND FIELDS WILL BECOME SOMEWHAT MUDDLED IN
CHARLESTON HARBOR AND THE NEARBY COASTAL WATERS DUE TO CONVECTION.
WE/RE STARTING TO SEE A LITTLE SWELL ENERGY FROM DISTANT HURRICANE
EDOUARD APPROACHING OUR WATERS FROM THE EAST...BUT AVERAGE WAVE
HEIGHTS WILL BE HELD TO AROUND 2 FT THROUGHOUT THE DAY. MARINERS
ARE ALERTED TO A FEW STRONGER STORMS WHICH CAN PRODUCE FREQUENT
LIGHTNING...HEAVY RAINS AND GUSTY WINDS.

TONIGHT...LONG PERIOD SWELLS FROM HURRICANE EDOUARD WILL BEGIN TO
AFFECT THE WATERS WITH PERIODS OF 11-14 SECONDS. SEAS OF 1-2 FT
WILL BUILD TO 2-4 FT NEARSHORE WATERS AND 4-5 FT OFFSHORE WATERS.
ATTM IT APPEARS SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS...ALTHOUGH IT WILL BE CLOSE FOR THE GEORGIA OFFSHORE
WATERS.

WEDNESDAY AND THURSDAY...A COLD FRONT WILL PROGRESS INTO AND
THROUGH THE WATERS DURING THE MID WEEK PERIOD. LIGHT WINDS IN
ADVANCE OF THE FRONT WEDNESDAY WILL BECOME NORTH/NORTHEAST AND
INCREASE IN ITS WAKE BY THURSDAY. SEAS WILL BE COMPRISED MAINLY OF
LONG PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND
2 TO 4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS FAR OFFSHORE AND REMAINS FAIRLY
STATIONARY ALONG THE PERIPHERY OF AN INLAND WEDGE OF HIGH
PRESSURE. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE FOR
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...BEFORE
CONDITIONS MODERATE WITHIN A TRANSITIONING PATTERN BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL
ARRIVE AT THE BEACHES LATE THIS AFTERNOON AND CONTINUE INTO
THURSDAY. THERE DOES NOT APPEAR TO BE MUCH MORE THAN ABOUT 1 OR 2 FT
SWELL THAT MAKES IT TO THE BEACHES BY LATE AFTERNOON...SO THE RIP
CURRENT RISK WILL REMAIN IN THE LOW CATEGORY FOR TODAY. LARGER
SWELLS AROUND 3 FT WILL OCCUR WEDNESDAY INTO THURSDAY AND THIS
WILL LEAD TO AN ENHANCED RISK OF RIP CURRENTS. FOR FRIDAY THROUGH
SUNDAY SWELL FROM EDOUARD WILL DIMINISH...BUT STRONGER NE WINDS
WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK OF RIP CURRENTS
TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING IN PARTS
OF THE AREA. HIGH RESOLUTION MODELS ARE SHOWING A DISTINCT SIGNAL
THAT AN AREA OF HEAVY RAIN WILL SETUP IN THE AREA FROM SAVANNAH
SOUTH TO DARIEN AND OVER TO SPRINGFIELD AND GLENNVILLE FOR SEVERAL
HOURS THIS AFTERNOON ALONG A PINNED SEA BREEZE CIRCULATION.
ALTHOUGH STORM MOTIONS WILL BE FASTER THAN PREVIOUS DAYS...THE
POTENTIAL FOR NUMEROUS MESOSCALE BOUNDARY INTERACTIONS...STRONG
UPPER DIVERGENCE AND HIGH PWAT VALUES APPROACHING 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR MID SEPTEMBER SUGGEST THERE IS A HIGH
POTENTIAL FOR EXCESSIVE HOURLY RAINFALL RATES EXCEEDING 2-3
IN/HR...WHICH IS NEAR OR HIGHER THAN THE LATEST 1-HR FLASH FLOOD
GUIDANCE. IN ADDITION...SOME AREAS HAVE ALREADY SEEN IN EXCESS OF
6 INCHES OVER THE PAST FEW DAYS.

A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING TODAY. THE COASTAL SOUTH CAROLINA
ZONES HAVE BEEN INCLUDED IN THE WATCH MAINLY TO ACCOUNT FOR
POSSIBLE HEAVY RAIN FALLING AROUND HIGH TIDE THIS AFTERNOON.
SIMILAR TO THE PAST FEW DAYS...ISOLATED RAIN AMOUNTS IN EXCESS OF
4 OR EVEN 5 INCHES WILL BE POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 161426
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1026 AM EDT TUE SEP 16 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND
PUSH THROUGH THE REGION LATE WEDNESDAY. AN INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT INTO THE
WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A BROAD LARGE SCALE TROUGH WILL PREVAIL ACROSS THE EASTERN HALF OF
THE NATION TODAY AS SHORT WAVE ENERGY CONTINUES TO FEED INTO THE
TROUGH WITHIN THE WEST/NW FLOW ALOFT. OUR SURFACE PATTERN IS WEAK
BUT DEFINED BY DEVELOPING PRE-FRONTAL TROUGH ALIGNED NE-SW THAT
LOOKS TO STAY OFF TO OUR NW THROUGH DARK. THIS SCENARIO SETS THE
STAGE FOR MORE MORE FAIRLY ACTIVE CONVECTIVE AFTERNOON.

WATER VAPOR SATELLITE IMAGES SHOWING A COUPLE OF MID LEVEL
IMPULSES HEADING OUR WAY FROM UPSTREAM. ONE IS OVER SW GA AND THE
SECOND IS A STRUNG OUT VORT LOBE FROM NC TO NORTHERN GA/AL. THESE
FEATURES WILL ARRIVE DURING THIS AFTERNOON OR EVENING...AND THAT
PLUS UPPER DIFLUENCE ASSOCIATED WITH THE RIGHT REAR QUAD OF AN
250 MB JET WILL SUPPLY THE NECESSARY FORCING FOR ASCENT.
MEANWHILE THERE IS STILL AN ABUNDANCE OF MOISTURE...UP ALMOST AT 2
STANDARD DEVIATIONS ABOVE NORMAL. STEERING FLOW IS A LITTLE MORE
NOTICEABLE THAN RECENT DAYS...BUT STILL SLOW ENOUGH TO SUPPORT
LIMITED MOVEMENT TO OUR SHOWERS AND T-STORMS. PLUS THE CONVECTION
WILL BE STEERED TOWARD THE COAST WITH THE WEST/NW FLOW AND WILL
BUMP UP AGAINST THE PINNED SEA BREEZE...WHICH IMPLIES THAT A
PILING UP OF RAINFALL CAN OCCUR AS IT HAS NOWHERE FURTHER EAST OR
SE TO GO...STUCK AT THE SEA BREEZE BOUNDARY. WE ARE STILL HITTING
THE COASTAL ZONES OF SC AND AREAS SOUTH OF I-16 IN SE GA WITH THE
FLASH FLOOD WATCH...AND IT/S IN THESE AREAS THAT HAVE THE HIGHEST
POPS IN THE 60-70 PERCENT RANGE.

THERE IS ONLY A SMALL RISK FOR LATE MORNING CONVECTION WITH A
LITTLE CAPPING IN PLACE AND NO REAL TRIGGERING MECHANISMS. BUT
COVERAGE WILL QUICKLY INCREASE DURING THE EARLY AND MID AFTERNOON
OVER OUR EASTERN AND SOUTHERN ZONES...WHERE RAINFALL WILL BE HEAVY
AT TIMES. THIS WILL RESULT FROM THE PERTURBATIONS ALOFT...THE SEA
BREEZE...DIFFERENTIAL HEATING BOUNDARIES FROM MORNING FOG/STRATUS
AND OUTFLOW BOUNDARY INTERACTIONS OCCUR.

ALSO OF NOTE...THERE IS A TAD BIT DRIER AND COLDER AIR IN THE MID
LEVELS AND MORE MOVEMENT IN THE TROPOSPHERE THAN OF LATE.
MODIFIED 12Z SOUNDINGS ARE MORE IMPRESSIVE THERMODYNAMICALLY THAN
THE FORECAST SOUNDINGS...AND MIGHT ALLOW FOR A FEW STRONGER OR
EVEN MARGINALLY SEVERE STORMS WHERE THE BOUNDARY
INTERACTIONS...MERGERS AND/OR COLLISIONS OCCUR. THIS IS A LOW END
PROBABILITY...BUT WORTHY OF TALKING ABOUT.

DOWNSLOPE FLOW OFF THE MOUNTAINS AND WARM ADVECTION IN ADVANCE OF
THE SURFACE TROUGH AND UPSTREAM COLD FRONT WILL NEGATE THE EFFECTS
OF EXTENSIVE CLOUD COVER TO WARM TEMPS YET AGAIN ABOVE
CLIMATOLOGICAL NORMS. THERE IS EVEN SOME POCKETS OF DECENT
INSOLATION BETWEEN LARGE BREAKS IN THE CLOUD COVER THROWN INTO THE
MIX. WE MIGHT BE A LITTLE CONSERVATIVE ON ACTUAL HIGHS...BUT WE
HAVE TWEAKED TEMPS A DEGREE OR 2...MAINLY INTO THE UPPER 80S OR
NEAR 90 AWAY FROM THE IMMEDIATE COAST. PENDING TRENDS WE MIGHT
EVEN NEED TO GO A TAD HIGHER. KEEP IN MIND THAT ONCE CONVECTION
INITIATES AND COVERAGE SPREADS OUT THAT OUR DIURNAL TEMP CURVE
WILL NEED BIG ADJUSTMENTS. WE HAVE LEANED THIS WAY IN OUR HOURLY
TEMP FORECAST...BUT NO DOUBT FUTURE AMENDMENTS WILL BE REQUIRED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...CONVECTION WILL QUICKLY WANE THIS EVENING WITH THE LOSS
OF INSOLATION. THE RISK FOR RAINFALL WILL GRADUALLY SHIFT OFFSHORE
CLOSER TO THE WESTERN WALL OF THE GULF STREAM AS A COLD FRONT
QUICKLY APPROACHES FROM THE NORTH. THE FRONT LOOKS TO REMAIN NORTH
AND NORTHWEST OF THE AREA THROUGH SUNRISE WEDNESDAY. SOME CLEARING
WILL LIKELY TAKE HOLD EARLY WEDNESDAY...ESPECIALLY ACROSS THE
WESTERN ZONES. WILL HAVE TO WATCH FOR POSSIBLE LOW STRATUS AND FOG
ONCE AGAIN GIVEN THE WET GROUNDS AND THE LIGHT WIND FIELDS THAT
WILL BE IN PLACE.

WEDNESDAY...THE SURFACE TROUGH WILL HAVE SHIFTED OFF THE SOUTHEAST
COASTLINE BY DAYBREAK...JUST DOWNSTREAM OF A SERIES OF SHORTWAVES
EMBEDDED WITHIN THE BASE OF A SHARPENING UPPER TROUGH AXIS.
PROGRESSION OF A STRONG COLD FRONT THROUGH THE FORECAST AREA
WILL LIKELY BE DELAYED UNTIL THE EVENING OR NIGHTTIME
PERIOD...WHEN A MORE DISTINCT AIR MASS CHANGE IS EVIDENT ALONG THE
LEADING EDGE OF STRONG HIGH PRESSURE BUILDING FROM THE
WEST/NORTHWEST. THE RIBBON OF DEEP LAYER MOISTURE RESPONSIBLE FOR
SEVERAL DAYS OF HEAVY RAIN EARLIER IN THE WEEK WILL HAVE MOVED TO
THE EAST/SOUTHEAST WITH THE SURFACE TROUGH. HOWEVER...THERE
APPEARS SUFFICIENT RESIDUAL MOISTURE TO SUPPORT SCATTERED
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON TIME
FRAME...ESPECIALLY AS SHORTWAVE ENERGY TRACKS THROUGH THE REGION
AND SEABREEZE DEVELOPMENT PROVIDES SOME FORCING/CONVERGENCE.
ISOLATED SHOWERS/THUNDERSTORMS COULD ACCOMPANY THE FRONT TOWARD
THE COASTLINE THROUGH MIDNIGHT...AND THEN EXPECT BEST RAIN CHANCES
TO SHIFT OVER THE MARINE ZONES DURING THE PRE-DAWN HOURS. HIGH
TEMPERATURES WILL ONCE AGAIN RISE ABOVE SEASONAL NORMALS WITHIN
DOWNSLOPE FLOW AND PRE-FRONTAL COMPRESSION...PEAKING IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES WILL
STILL BE A DEGREE OR TWO ABOVE NORMAL...YET TREND COOLER THAN
PREVIOUS NIGHTS BY FALLING INTO THE MID TO UPPER 60S.

THURSDAY AND FRIDAY...NORTHEAST FLOW DEVELOPING IN THE WAKE OF THE
FRONT AND WITHIN BUILDING HIGH PRESSURE FROM THE NORTH WILL
SUPPORT A NOTABLE COOLING TREND LATE IN THE WEEK. HIGH
TEMPERATURES ON THURSDAY WILL ONLY PEAK IN THE LOW TO MID
80S...WHILE ONLY RISING TO THE LOWER 80S FOR FRIDAY AFTERNOON.
NIGHTTIME LOW TEMPERATURES WILL ALSO REFLECT THE AIR MASS
CHANGE...AS LOWER DEWPOINTS/DRIER AIR ALLOW TEMPERATURES TO FALL
INTO THE LOW TO MID 60S. AS THE CENTER OF THE SURFACE HIGH TRACKS
FROM THE GREAT LAKES REGION THURSDAY AND INTO THE NEW ENGLAND
STATES FRIDAY...THE INLAND WEDGE WILL AMPLIFY DOWN THE
APPALACHIANS AND A COASTAL TROUGH WILL TAKE SHAPE ON THE SOUTHERN
COASTLINE. THIS PATTERN COULD ALLOW A DISTINCT GRADIENT IN
PRECIPITATION POTENTIAL BETWEEN THE DRIER INLAND AREAS AND COASTAL
COUNTIES NEAR CONVERGENCE ALONG THE TROUGH. RAIN COVERAGE WILL
STILL BE CONSIDERABLY LOWER THAN EARLIER IN THE WEEK FOR ALL
LOCATIONS...AND WILL ADVERTISE JUST ISOLATED SHOWERS/THUNDERSTORMS
INLAND AND SCATTERED ALONG THE COAST...MAINLY DURING THE AFTERNOON
PERIOD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
KCHS...VFR INTO THIS AFTERNOON. CHANCES FOR TSTMS THIS AFTERNOON
ROUGHLY 19-21Z TIME FRAME. TEMPO FOR MVFR IMPACTS FROM TSTMS WILL
BE SHOWN.

KSAV...VFR EXPECTED 15-16Z WITH TSTM IMPACTS POSSIBLE 19-22Z.
LIMITED TSTM IMPACTS TO MVFR FOR NOW...BUT IFR CONDITIONS OR LOWER
CERTAINLY POSSIBLE IN HEAVIER DOWNPOURS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY...WEST AND NW WINDS AT LESS THAN 10 OR 15 KT THIS MORNING
WILL DIMINISH WITH TIME...AS A FAIRLY NEBULOUS PRESSURE PATTERN
SETS UP UNDERNEATH WEAK HIGH PRESSURE AND IN ADVANCE OF OUR NEXT
UPSTREAM COLD FRONT. THIS WILL ALLOW FOR RESULTANT SOUTH/SW SEA
BREEZE CIRCULATIONS TO KICK IN DURING THE AFTERNOON...ALTHOUGH AT
TIMES THE WIND FIELDS MAY BECOME SOMEWHAT MUDDLED IN CHARLESTON
HARBOR AND THE NEARBY COASTAL WATERS DUE TO CONVECTION. WE/RE
STARTING TO SEE A LITTLE SWELL ENERGY FROM DISTANT HURRICANE
EDOUARD APPROACHING OUR WATERS FROM THE EAST...BUT AVERAGE WAVE
HEIGHTS WILL BE HELD TO AROUND 2 FT THROUGHOUT THE DAY. MARINERS
ARE ALERTED TO A FEW STRONGER STORMS WHICH CAN PRODUCE FREQUENT
LIGHTNING...HEAVY RAINS AND GUSTY WINDS.

TONIGHT...LONG PERIOD SWELLS FROM HURRICANE EDOUARD WILL BEGIN TO
AFFECT THE WATERS WITH PERIODS OF 11-14 SECONDS. SEAS OF 1-2 FT
WILL BUILD TO 2-4 FT NEARSHORE WATERS AND 4-5 FT OFFSHORE WATERS.
ATTM IT APPEARS SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS...ALTHOUGH IT WILL BE CLOSE FOR THE GEORGIA OFFSHORE
WATERS.

WEDNESDAY AND THURSDAY...A COLD FRONT WILL PROGRESS INTO AND
THROUGH THE WATERS DURING THE MID WEEK PERIOD. LIGHT WINDS IN
ADVANCE OF THE FRONT WEDNESDAY WILL BECOME NORTH/NORTHEAST AND
INCREASE IN ITS WAKE BY THURSDAY. SEAS WILL BE COMPRISED MAINLY OF
LONG PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND
2 TO 4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS FAR OFFSHORE AND REMAINS FAIRLY
STATIONARY ALONG THE PERIPHERY OF AN INLAND WEDGE OF HIGH
PRESSURE. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE FOR
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...BEFORE
CONDITIONS MODERATE WITHIN A TRANSITIONING PATTERN BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL
ARRIVE AT THE BEACHES LATE THIS AFTERNOON AND CONTINUE INTO
THURSDAY. THERE DOES NOT APPEAR TO BE MUCH MORE THAN ABOUT 1 OR 2 FT
SWELL THAT MAKES IT TO THE BEACHES BY LATE AFTERNOON...SO THE RIP
CURRENT RISK WILL REMAIN IN THE LOW CATEGORY FOR TODAY. LARGER
SWELLS AROUND 3 FT WILL OCCUR WEDNESDAY INTO THURSDAY AND THIS
WILL LEAD TO AN ENHANCED RISK OF RIP CURRENTS. FOR FRIDAY THROUGH
SUNDAY SWELL FROM EDOUARD WILL DIMINISH...BUT STRONGER NE WINDS
WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK OF RIP CURRENTS
TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING IN PARTS
OF THE AREA. HIGH RESOLUTION MODELS ARE SHOWING A DISTINCT SIGNAL
THAT AN AREA OF HEAVY RAIN WILL SETUP IN THE AREA FROM SAVANNAH
SOUTH TO DARIEN AND OVER TO SPRINGFIELD AND GLENNVILLE FOR SEVERAL
HOURS THIS AFTERNOON ALONG A PINNED SEA BREEZE CIRCULATION.
ALTHOUGH STORM MOTIONS WILL BE FASTER THAN PREVIOUS DAYS...THE
POTENTIAL FOR NUMEROUS MESOSCALE BOUNDARY INTERACTIONS...STRONG
UPPER DIVERGENCE AND HIGH PWAT VALUES APPROACHING 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR MID SEPTEMBER SUGGEST THERE IS A HIGH
POTENTIAL FOR EXCESSIVE HOURLY RAINFALL RATES EXCEEDING 2-3
IN/HR...WHICH IS NEAR OR HIGHER THAN THE LATEST 1-HR FLASH FLOOD
GUIDANCE. IN ADDITION...SOME AREAS HAVE ALREADY SEEN IN EXCESS OF
6 INCHES OVER THE PAST FEW DAYS.

A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING TODAY. THE COASTAL SOUTH CAROLINA
ZONES HAVE BEEN INCLUDED IN THE WATCH MAINLY TO ACCOUNT FOR
POSSIBLE HEAVY RAIN FALLING AROUND HIGH TIDE THIS AFTERNOON.
SIMILAR TO THE PAST FEW DAYS...ISOLATED RAIN AMOUNTS IN EXCESS OF
4 OR EVEN 5 INCHES WILL BE POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 161426
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1026 AM EDT TUE SEP 16 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND
PUSH THROUGH THE REGION LATE WEDNESDAY. AN INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT INTO THE
WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A BROAD LARGE SCALE TROUGH WILL PREVAIL ACROSS THE EASTERN HALF OF
THE NATION TODAY AS SHORT WAVE ENERGY CONTINUES TO FEED INTO THE
TROUGH WITHIN THE WEST/NW FLOW ALOFT. OUR SURFACE PATTERN IS WEAK
BUT DEFINED BY DEVELOPING PRE-FRONTAL TROUGH ALIGNED NE-SW THAT
LOOKS TO STAY OFF TO OUR NW THROUGH DARK. THIS SCENARIO SETS THE
STAGE FOR MORE MORE FAIRLY ACTIVE CONVECTIVE AFTERNOON.

WATER VAPOR SATELLITE IMAGES SHOWING A COUPLE OF MID LEVEL
IMPULSES HEADING OUR WAY FROM UPSTREAM. ONE IS OVER SW GA AND THE
SECOND IS A STRUNG OUT VORT LOBE FROM NC TO NORTHERN GA/AL. THESE
FEATURES WILL ARRIVE DURING THIS AFTERNOON OR EVENING...AND THAT
PLUS UPPER DIFLUENCE ASSOCIATED WITH THE RIGHT REAR QUAD OF AN
250 MB JET WILL SUPPLY THE NECESSARY FORCING FOR ASCENT.
MEANWHILE THERE IS STILL AN ABUNDANCE OF MOISTURE...UP ALMOST AT 2
STANDARD DEVIATIONS ABOVE NORMAL. STEERING FLOW IS A LITTLE MORE
NOTICEABLE THAN RECENT DAYS...BUT STILL SLOW ENOUGH TO SUPPORT
LIMITED MOVEMENT TO OUR SHOWERS AND T-STORMS. PLUS THE CONVECTION
WILL BE STEERED TOWARD THE COAST WITH THE WEST/NW FLOW AND WILL
BUMP UP AGAINST THE PINNED SEA BREEZE...WHICH IMPLIES THAT A
PILING UP OF RAINFALL CAN OCCUR AS IT HAS NOWHERE FURTHER EAST OR
SE TO GO...STUCK AT THE SEA BREEZE BOUNDARY. WE ARE STILL HITTING
THE COASTAL ZONES OF SC AND AREAS SOUTH OF I-16 IN SE GA WITH THE
FLASH FLOOD WATCH...AND IT/S IN THESE AREAS THAT HAVE THE HIGHEST
POPS IN THE 60-70 PERCENT RANGE.

THERE IS ONLY A SMALL RISK FOR LATE MORNING CONVECTION WITH A
LITTLE CAPPING IN PLACE AND NO REAL TRIGGERING MECHANISMS. BUT
COVERAGE WILL QUICKLY INCREASE DURING THE EARLY AND MID AFTERNOON
OVER OUR EASTERN AND SOUTHERN ZONES...WHERE RAINFALL WILL BE HEAVY
AT TIMES. THIS WILL RESULT FROM THE PERTURBATIONS ALOFT...THE SEA
BREEZE...DIFFERENTIAL HEATING BOUNDARIES FROM MORNING FOG/STRATUS
AND OUTFLOW BOUNDARY INTERACTIONS OCCUR.

ALSO OF NOTE...THERE IS A TAD BIT DRIER AND COLDER AIR IN THE MID
LEVELS AND MORE MOVEMENT IN THE TROPOSPHERE THAN OF LATE.
MODIFIED 12Z SOUNDINGS ARE MORE IMPRESSIVE THERMODYNAMICALLY THAN
THE FORECAST SOUNDINGS...AND MIGHT ALLOW FOR A FEW STRONGER OR
EVEN MARGINALLY SEVERE STORMS WHERE THE BOUNDARY
INTERACTIONS...MERGERS AND/OR COLLISIONS OCCUR. THIS IS A LOW END
PROBABILITY...BUT WORTHY OF TALKING ABOUT.

DOWNSLOPE FLOW OFF THE MOUNTAINS AND WARM ADVECTION IN ADVANCE OF
THE SURFACE TROUGH AND UPSTREAM COLD FRONT WILL NEGATE THE EFFECTS
OF EXTENSIVE CLOUD COVER TO WARM TEMPS YET AGAIN ABOVE
CLIMATOLOGICAL NORMS. THERE IS EVEN SOME POCKETS OF DECENT
INSOLATION BETWEEN LARGE BREAKS IN THE CLOUD COVER THROWN INTO THE
MIX. WE MIGHT BE A LITTLE CONSERVATIVE ON ACTUAL HIGHS...BUT WE
HAVE TWEAKED TEMPS A DEGREE OR 2...MAINLY INTO THE UPPER 80S OR
NEAR 90 AWAY FROM THE IMMEDIATE COAST. PENDING TRENDS WE MIGHT
EVEN NEED TO GO A TAD HIGHER. KEEP IN MIND THAT ONCE CONVECTION
INITIATES AND COVERAGE SPREADS OUT THAT OUR DIURNAL TEMP CURVE
WILL NEED BIG ADJUSTMENTS. WE HAVE LEANED THIS WAY IN OUR HOURLY
TEMP FORECAST...BUT NO DOUBT FUTURE AMENDMENTS WILL BE REQUIRED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...CONVECTION WILL QUICKLY WANE THIS EVENING WITH THE LOSS
OF INSOLATION. THE RISK FOR RAINFALL WILL GRADUALLY SHIFT OFFSHORE
CLOSER TO THE WESTERN WALL OF THE GULF STREAM AS A COLD FRONT
QUICKLY APPROACHES FROM THE NORTH. THE FRONT LOOKS TO REMAIN NORTH
AND NORTHWEST OF THE AREA THROUGH SUNRISE WEDNESDAY. SOME CLEARING
WILL LIKELY TAKE HOLD EARLY WEDNESDAY...ESPECIALLY ACROSS THE
WESTERN ZONES. WILL HAVE TO WATCH FOR POSSIBLE LOW STRATUS AND FOG
ONCE AGAIN GIVEN THE WET GROUNDS AND THE LIGHT WIND FIELDS THAT
WILL BE IN PLACE.

WEDNESDAY...THE SURFACE TROUGH WILL HAVE SHIFTED OFF THE SOUTHEAST
COASTLINE BY DAYBREAK...JUST DOWNSTREAM OF A SERIES OF SHORTWAVES
EMBEDDED WITHIN THE BASE OF A SHARPENING UPPER TROUGH AXIS.
PROGRESSION OF A STRONG COLD FRONT THROUGH THE FORECAST AREA
WILL LIKELY BE DELAYED UNTIL THE EVENING OR NIGHTTIME
PERIOD...WHEN A MORE DISTINCT AIR MASS CHANGE IS EVIDENT ALONG THE
LEADING EDGE OF STRONG HIGH PRESSURE BUILDING FROM THE
WEST/NORTHWEST. THE RIBBON OF DEEP LAYER MOISTURE RESPONSIBLE FOR
SEVERAL DAYS OF HEAVY RAIN EARLIER IN THE WEEK WILL HAVE MOVED TO
THE EAST/SOUTHEAST WITH THE SURFACE TROUGH. HOWEVER...THERE
APPEARS SUFFICIENT RESIDUAL MOISTURE TO SUPPORT SCATTERED
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON TIME
FRAME...ESPECIALLY AS SHORTWAVE ENERGY TRACKS THROUGH THE REGION
AND SEABREEZE DEVELOPMENT PROVIDES SOME FORCING/CONVERGENCE.
ISOLATED SHOWERS/THUNDERSTORMS COULD ACCOMPANY THE FRONT TOWARD
THE COASTLINE THROUGH MIDNIGHT...AND THEN EXPECT BEST RAIN CHANCES
TO SHIFT OVER THE MARINE ZONES DURING THE PRE-DAWN HOURS. HIGH
TEMPERATURES WILL ONCE AGAIN RISE ABOVE SEASONAL NORMALS WITHIN
DOWNSLOPE FLOW AND PRE-FRONTAL COMPRESSION...PEAKING IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES WILL
STILL BE A DEGREE OR TWO ABOVE NORMAL...YET TREND COOLER THAN
PREVIOUS NIGHTS BY FALLING INTO THE MID TO UPPER 60S.

THURSDAY AND FRIDAY...NORTHEAST FLOW DEVELOPING IN THE WAKE OF THE
FRONT AND WITHIN BUILDING HIGH PRESSURE FROM THE NORTH WILL
SUPPORT A NOTABLE COOLING TREND LATE IN THE WEEK. HIGH
TEMPERATURES ON THURSDAY WILL ONLY PEAK IN THE LOW TO MID
80S...WHILE ONLY RISING TO THE LOWER 80S FOR FRIDAY AFTERNOON.
NIGHTTIME LOW TEMPERATURES WILL ALSO REFLECT THE AIR MASS
CHANGE...AS LOWER DEWPOINTS/DRIER AIR ALLOW TEMPERATURES TO FALL
INTO THE LOW TO MID 60S. AS THE CENTER OF THE SURFACE HIGH TRACKS
FROM THE GREAT LAKES REGION THURSDAY AND INTO THE NEW ENGLAND
STATES FRIDAY...THE INLAND WEDGE WILL AMPLIFY DOWN THE
APPALACHIANS AND A COASTAL TROUGH WILL TAKE SHAPE ON THE SOUTHERN
COASTLINE. THIS PATTERN COULD ALLOW A DISTINCT GRADIENT IN
PRECIPITATION POTENTIAL BETWEEN THE DRIER INLAND AREAS AND COASTAL
COUNTIES NEAR CONVERGENCE ALONG THE TROUGH. RAIN COVERAGE WILL
STILL BE CONSIDERABLY LOWER THAN EARLIER IN THE WEEK FOR ALL
LOCATIONS...AND WILL ADVERTISE JUST ISOLATED SHOWERS/THUNDERSTORMS
INLAND AND SCATTERED ALONG THE COAST...MAINLY DURING THE AFTERNOON
PERIOD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
KCHS...VFR INTO THIS AFTERNOON. CHANCES FOR TSTMS THIS AFTERNOON
ROUGHLY 19-21Z TIME FRAME. TEMPO FOR MVFR IMPACTS FROM TSTMS WILL
BE SHOWN.

KSAV...VFR EXPECTED 15-16Z WITH TSTM IMPACTS POSSIBLE 19-22Z.
LIMITED TSTM IMPACTS TO MVFR FOR NOW...BUT IFR CONDITIONS OR LOWER
CERTAINLY POSSIBLE IN HEAVIER DOWNPOURS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY...WEST AND NW WINDS AT LESS THAN 10 OR 15 KT THIS MORNING
WILL DIMINISH WITH TIME...AS A FAIRLY NEBULOUS PRESSURE PATTERN
SETS UP UNDERNEATH WEAK HIGH PRESSURE AND IN ADVANCE OF OUR NEXT
UPSTREAM COLD FRONT. THIS WILL ALLOW FOR RESULTANT SOUTH/SW SEA
BREEZE CIRCULATIONS TO KICK IN DURING THE AFTERNOON...ALTHOUGH AT
TIMES THE WIND FIELDS MAY BECOME SOMEWHAT MUDDLED IN CHARLESTON
HARBOR AND THE NEARBY COASTAL WATERS DUE TO CONVECTION. WE/RE
STARTING TO SEE A LITTLE SWELL ENERGY FROM DISTANT HURRICANE
EDOUARD APPROACHING OUR WATERS FROM THE EAST...BUT AVERAGE WAVE
HEIGHTS WILL BE HELD TO AROUND 2 FT THROUGHOUT THE DAY. MARINERS
ARE ALERTED TO A FEW STRONGER STORMS WHICH CAN PRODUCE FREQUENT
LIGHTNING...HEAVY RAINS AND GUSTY WINDS.

TONIGHT...LONG PERIOD SWELLS FROM HURRICANE EDOUARD WILL BEGIN TO
AFFECT THE WATERS WITH PERIODS OF 11-14 SECONDS. SEAS OF 1-2 FT
WILL BUILD TO 2-4 FT NEARSHORE WATERS AND 4-5 FT OFFSHORE WATERS.
ATTM IT APPEARS SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS...ALTHOUGH IT WILL BE CLOSE FOR THE GEORGIA OFFSHORE
WATERS.

WEDNESDAY AND THURSDAY...A COLD FRONT WILL PROGRESS INTO AND
THROUGH THE WATERS DURING THE MID WEEK PERIOD. LIGHT WINDS IN
ADVANCE OF THE FRONT WEDNESDAY WILL BECOME NORTH/NORTHEAST AND
INCREASE IN ITS WAKE BY THURSDAY. SEAS WILL BE COMPRISED MAINLY OF
LONG PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND
2 TO 4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS FAR OFFSHORE AND REMAINS FAIRLY
STATIONARY ALONG THE PERIPHERY OF AN INLAND WEDGE OF HIGH
PRESSURE. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE FOR
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...BEFORE
CONDITIONS MODERATE WITHIN A TRANSITIONING PATTERN BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL
ARRIVE AT THE BEACHES LATE THIS AFTERNOON AND CONTINUE INTO
THURSDAY. THERE DOES NOT APPEAR TO BE MUCH MORE THAN ABOUT 1 OR 2 FT
SWELL THAT MAKES IT TO THE BEACHES BY LATE AFTERNOON...SO THE RIP
CURRENT RISK WILL REMAIN IN THE LOW CATEGORY FOR TODAY. LARGER
SWELLS AROUND 3 FT WILL OCCUR WEDNESDAY INTO THURSDAY AND THIS
WILL LEAD TO AN ENHANCED RISK OF RIP CURRENTS. FOR FRIDAY THROUGH
SUNDAY SWELL FROM EDOUARD WILL DIMINISH...BUT STRONGER NE WINDS
WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK OF RIP CURRENTS
TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING IN PARTS
OF THE AREA. HIGH RESOLUTION MODELS ARE SHOWING A DISTINCT SIGNAL
THAT AN AREA OF HEAVY RAIN WILL SETUP IN THE AREA FROM SAVANNAH
SOUTH TO DARIEN AND OVER TO SPRINGFIELD AND GLENNVILLE FOR SEVERAL
HOURS THIS AFTERNOON ALONG A PINNED SEA BREEZE CIRCULATION.
ALTHOUGH STORM MOTIONS WILL BE FASTER THAN PREVIOUS DAYS...THE
POTENTIAL FOR NUMEROUS MESOSCALE BOUNDARY INTERACTIONS...STRONG
UPPER DIVERGENCE AND HIGH PWAT VALUES APPROACHING 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR MID SEPTEMBER SUGGEST THERE IS A HIGH
POTENTIAL FOR EXCESSIVE HOURLY RAINFALL RATES EXCEEDING 2-3
IN/HR...WHICH IS NEAR OR HIGHER THAN THE LATEST 1-HR FLASH FLOOD
GUIDANCE. IN ADDITION...SOME AREAS HAVE ALREADY SEEN IN EXCESS OF
6 INCHES OVER THE PAST FEW DAYS.

A FLASH FLOOD WATCH HAS BEEN MAINTAINED FOR AREAS SOUTH OF I-16
IN SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH
CAROLINA THROUGH 8 PM EDT...AS THESE AREAS HAVE THE HIGHEST
POTENTIAL FOR FLASH FLOODING TODAY. THE COASTAL SOUTH CAROLINA
ZONES HAVE BEEN INCLUDED IN THE WATCH MAINLY TO ACCOUNT FOR
POSSIBLE HEAVY RAIN FALLING AROUND HIGH TIDE THIS AFTERNOON.
SIMILAR TO THE PAST FEW DAYS...ISOLATED RAIN AMOUNTS IN EXCESS OF
4 OR EVEN 5 INCHES WILL BE POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR GAZ114>119-
     137>141.
SC...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 161037
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
637 AM EDT TUE SEP 16 2014

...ONE LAST DAY OF HEAVY RAIN AND POSSIBLE FLASH FLOODING...

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND
PUSH THROUGH THE REGION LATE WEDNESDAY. AN INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT INTO THE
WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE SUNRISE UPDATE...

1. CANCELLED THE DENSE FOG ADVISORY A LITTLE EARLY. VISIBILITIES
HAVE IMPROVED SLIGHTLY OVER THE PAST 2 HOURS AS WINDS TURN
NORTHWEST IN THE WAKE OF A WEAK SURFACE TROUGH. AREAS OF FOG WILL
PERSIST THROUGH ABOUT 9 AM.

THE REST OF THE FORECAST IS ON TRACK.

TODAY...ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING.
WEAK SHORTWAVE ENERGY MOVING ACROSS THE CENTRAL PLAINS THIS
MORNING IS FORECAST TO MOVE QUICKLY EAST/SOUTHEAST TODAY...
APPROACHING THE SOUTHEAST U.S. THIS AFTERNOON. MODELS SHOW BROAD
DIFLUENCE DEVELOPING AHEAD OF THIS FEATURE WHILE THE RIGHT
ENTRANCE REGION OF YET ANOTHER 250 HPA JET STREAK PASSES OVERHEAD
DURING PEAK HEATING. A NORTHWEST FLOW ALOFT WILL RESULT IN THE
SEA BREEZE CIRCULATION BEING PINNED TO THE COAST FOR MUCH OF THE
DAY BEFORE SLOWLY SPREADING INLAND LATE. IT APPEARS CONVECTION
WILL LIKELY INITIATE THEN CONCENTRATE ALONG THE PINNED SEA BREEZE
CIRCULATION BY MID-AFTERNOON AND SPREAD VERY SLOWLY INLAND
COINCIDENT WITH THE SEA BREEZE ITSELF. SEVERAL HIGH RESOLUTION
MODELS SHOW A DISTINCT SIGNATURE THAT AN AREA OF CONCENTRATED
CONVECTION WILL CLUSTER IN THE SAVANNAH...DARIEN...SPRINGFIELD...
GLENNVILLE AREA BY MID-LATE AFTERNOON. THIS AREA OF CONVECTION
WILL POSE A RISK FOR FLASH FLOODING. SEE THE HYDROLOGY SECTION
BELOW FOR ADDITIONAL INFORMATION ON THE THREAT FOR HEAVY RAIN AND
FLOODING.

POPS WILL BE INCREASED SLIGHTLY ACROSS THE COASTAL ZONES THIS
AFTERNOON...RANGING FROM 60 PERCENT ACROSS THE CHARLESTON METRO
AREA TO 70 PERCENT FROM BEAUFORT AND SAVANNAH SOUTH...INCLUDING
AREAS SOUTH OF I-16. FATHER INLAND...MORE SCATTERED CONVECTION IS
EXPECTED...BUT WILL LIKELY BE A BIT MORE LOOSELY ORGANIZED. POPS
OF 30-50 PERCENT WILL BE MAINTAINED IN THIS AREA. HIGHS WILL TOP
OUT IN THE UPPER 80S INLAND WITH MID 80S AT THE BEACHES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...CONVECTION WILL QUICKLY WANE THIS EVENING WITH THE LOSS
OF INSOLATION. THE RISK FOR RAINFALL WILL GRADUALLY SHIFT OFFSHORE
CLOSER TO THE WESTERN WALL OF THE GULF STREAM AS A COLD FRONT
QUICKLY APPROACHES FROM THE NORTH. THE FRONT LOOKS TO REMAIN NORTH
AND NORTHWEST OF THE AREA THROUGH SUNRISE WEDNESDAY. SOME CLEARING
WILL LIKELY TAKE HOLD EARLY WEDNESDAY...ESPECIALLY ACROSS THE
WESTERN ZONES. WILL HAVE TO WATCH FOR POSSIBLE LOW STRATUS AND FOG
ONCE AGAIN GIVEN THE WET GROUNDS AND THE LIGHT WIND FIELDS THAT
WILL BE IN PLACE.

WEDNESDAY...THE SURFACE TROUGH WILL HAVE SHIFTED OFF THE SOUTHEAST
COASTLINE BY DAYBREAK...JUST DOWNSTREAM OF A SERIES OF SHORTWAVES
EMBEDDED WITHIN THE BASE OF A SHARPENING UPPER TROUGH AXIS.
PROGRESSION OF A STRONG COLD FRONT THROUGH THE FORECAST AREA
WILL LIKELY BE DELAYED UNTIL THE EVENING OR NIGHTTIME
PERIOD...WHEN A MORE DISTINCT AIR MASS CHANGE IS EVIDENT ALONG THE
LEADING EDGE OF STRONG HIGH PRESSURE BUILDING FROM THE
WEST/NORTHWEST. THE RIBBON OF DEEP LAYER MOISTURE RESPONSIBLE FOR
SEVERAL DAYS OF HEAVY RAIN EARLIER IN THE WEEK WILL HAVE MOVED TO
THE EAST/SOUTHEAST WITH THE SURFACE TROUGH. HOWEVER...THERE
APPEARS SUFFICIENT RESIDUAL MOISTURE TO SUPPORT SCATTERED
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON TIME
FRAME...ESPECIALLY AS SHORTWAVE ENERGY TRACKS THROUGH THE REGION
AND SEABREEZE DEVELOPMENT PROVIDES SOME FORCING/CONVERGENCE.
ISOLATED SHOWERS/THUNDERSTORMS COULD ACCOMPANY THE FRONT TOWARD
THE COASTLINE THROUGH MIDNIGHT...AND THEN EXPECT BEST RAIN CHANCES
TO SHIFT OVER THE MARINE ZONES DURING THE PRE-DAWN HOURS. HIGH
TEMPERATURES WILL ONCE AGAIN RISE ABOVE SEASONAL NORMALS WITHIN
DOWNSLOPE FLOW AND PRE-FRONTAL COMPRESSION...PEAKING IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES WILL
STILL BE A DEGREE OR TWO ABOVE NORMAL...YET TREND COOLER THAN
PREVIOUS NIGHTS BY FALLING INTO THE MID TO UPPER 60S.

THURSDAY AND FRIDAY...NORTHEAST FLOW DEVELOPING IN THE WAKE OF THE
FRONT AND WITHIN BUILDING HIGH PRESSURE FROM THE NORTH WILL
SUPPORT A NOTABLE COOLING TREND LATE IN THE WEEK. HIGH
TEMPERATURES ON THURSDAY WILL ONLY PEAK IN THE LOW TO MID
80S...WHILE ONLY RISING TO THE LOWER 80S FOR FRIDAY AFTERNOON.
NIGHTTIME LOW TEMPERATURES WILL ALSO REFLECT THE AIR MASS
CHANGE...AS LOWER DEWPOINTS/DRIER AIR ALLOW TEMPERATURES TO FALL
INTO THE LOW TO MID 60S. AS THE CENTER OF THE SURFACE HIGH TRACKS
FROM THE GREAT LAKES REGION THURSDAY AND INTO THE NEW ENGLAND
STATES FRIDAY...THE INLAND WEDGE WILL AMPLIFY DOWN THE
APPALACHIANS AND A COASTAL TROUGH WILL TAKE SHAPE ON THE SOUTHERN
COASTLINE. THIS PATTERN COULD ALLOW A DISTINCT GRADIENT IN
PRECIPITATION POTENTIAL BETWEEN THE DRIER INLAND AREAS AND COASTAL
COUNTIES NEAR CONVERGENCE ALONG THE TROUGH. RAIN COVERAGE WILL
STILL BE CONSIDERABLY LOWER THAN EARLIER IN THE WEEK FOR ALL
LOCATIONS...AND WILL ADVERTISE JUST ISOLATED SHOWERS/THUNDERSTORMS
INLAND AND SCATTERED ALONG THE COAST...MAINLY DURING THE AFTERNOON
PERIOD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
LOW STRATUS AND FOG IS THE PRIMARY CONCERN THROUGH SUNRISE.

KCHS...VFR EXPECTED TO RETURN 14-15Z. CHANCES FOR TSTMS THIS
AFTERNOON ROUGHLY 19-21Z TIME FRAME. TEMPO FOR MVFR IMPACTS FROM
TSTMS WILL BE SHOWN.

KSAV...VFR EXPECTED TO RETURN 13-15Z WITH TSTM IMPACTS POSSIBLE
19-22Z. LIMITED TSTM IMPACTS TO MVFR FOR NOW...BUT IFR CONDITIONS
OR LOWER CERTAINLY POSSIBLE IN HEAVIER DOWNPOURS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY...NEAR TERM CONCERNS CENTERS ON THE POTENTIAL FOR DENSE FOG
MOVING IN THE CHARLESTON HARBOR. HARBOR WEBCAMS SUGGEST CIGS ARE
SLOWLY LOWERING...BUT IT REMAINS UNCLEAR WHETHER VSBYS WILL DROP
ENOUGH PRIOR TO SUNRISE FOR A MARINE DENSE FOG ADVISORY. WILL
MAINTAIN A MENTION OF AREAS OF FOG FOR NOW AND CONTINUE TO MONITOR
TRENDS FOR A POSSIBLE MARINE DENSE FOG ADVISORY. OTHERWISE...LIGHT
WINDS WILL PERSIST AGAIN TODAY. LIGHT WEST/SOUTHWEST WINDS WILL
TURN MORE SOUTHERLY THIS AFTERNOON AS THE RESULTANT SEA BREEZE
TAKES HOLD. SPEEDS WILL REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT.

TONIGHT...LONG PERIOD SWELLS FROM HURRICANE EDOUARD WILL BEGIN TO
AFFECT THE WATERS WITH PERIODS OF 11-14 SECONDS. SEAS OF 1-2 FT
WILL BUILD TO 2-4 FT NEARSHORE WATERS AND 4-5 FT OFFSHORE WATERS.
ATTM IT APPEARS SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS...ALTHOUGH IT WILL BE CLOSE FOR THE GEORGIA OFFSHORE
WATERS.

WEDNESDAY AND THURSDAY...A COLD FRONT WILL PROGRESS INTO AND
THROUGH THE WATERS DURING THE MID WEEK PERIOD. LIGHT WINDS IN
ADVANCE OF THE FRONT WEDNESDAY WILL BECOME NORTH/NORTHEAST AND
INCREASE IN ITS WAKE BY THURSDAY. SEAS WILL BE COMPRISED MAINLY OF
LONG PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND
2 TO 4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS FAR OFFSHORE AND REMAINS FAIRLY
STATIONARY ALONG THE PERIPHERY OF AN INLAND WEDGE OF HIGH
PRESSURE. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE FOR
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...BEFORE
CONDITIONS MODERATE WITHIN A TRANSITIONING PATTERN BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL
ARRIVE AT THE BEACHES LATE THIS AFTERNOON AND CONTINUE INTO
THURSDAY. THERE DOES NOT APPEAR TO BE MUCH MORE THAN ABOUT 1 FT
SWELL THAT MAKES IT TO THE BEACHES BY LATE AFTERNOON...SO THE RIP
CURRENT RISK WILL REMAIN IN THE LOW CATEGORY FOR TODAY. LARGER
SWELLS AROUND 3 FT WILL OCCUR WEDNESDAY INTO THURSDAY AND THIS
WILL LEAD TO AN ENHANCED RISK OF RIP CURRENTS. FOR FRIDAY THROUGH
SUNDAY SWELL FROM EDOUARD WILL DIMINISH...BUT STRONGER NE WINDS
WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK OF RIP CURRENTS
TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING. HIGH
RESOLUTION MODELS ARE SHOWING A DISTINCT SIGNAL THAT AN AREA OF
HEAVY RAIN WILL SETUP IN THE AREA FROM SAVANNAH SOUTH TO DARIEN
AND OVER TO SPRINGFIELD AND GLENNVILLE FOR SEVERAL HOURS THIS
AFTERNOON ALONG A PINNED SEA BREEZE CIRCULATION. ALTHOUGH STORM
MOTIONS WILL BE FASTER THAN PREVIOUS DAYS...THE POTENTIAL FOR
NUMEROUS MESOSCALE BOUNDARY INTERACTIONS...STRONG UPPER DIVERGENCE
AND HIGH PWAT VALUES NEAR THE 99TH PERCENTILE SUGGEST THERE IS A
HIGH POTENTIAL FOR EXCESSIVE HOURLY RAINFALL RATES EXCEEDING 2-3
IN/HR...WHICH IS HIGHER THAN THE LATEST 1-HR FLASH FLOOD GUIDANCE.
IN ADDITION...SOME AREAS HAVE ALREADY SEEN IN EXCESS OF 6 INCHES
OVER THE PAST FEW DAYS.

A FLASH FLOOD WATCH WILL BE ISSUED FOR AREAS SOUTH OF I-16 IN
SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH CAROLINA
THROUGH 8 PM EDT AS THESE AREAS HAVE THE HIGHEST POTENTIAL FOR
FLASH FLOODING TODAY. THE COASTAL SOUTH CAROLINA ZONES WILL BE
INCLUDED IN THE WATCH MAINLY TO ACCOUNT FOR POSSIBLE HEAVY RAIN
FALLING AROUND HIGH TIDE THIS AFTERNOON. SIMILAR TO THE PAST FEW
DAYS...ISOLATED RAIN AMOUNTS IN EXCESS OF 5 INCHES WILL BE
POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ048>052.
MARINE...NONE.

&&

$$

ST/WMS






000
FXUS62 KCHS 160747
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
347 AM EDT TUE SEP 16 2014

...ONE LAST DAY OF HEAVY RAIN AND POSSIBLE FLASH FLOODING...

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND
PUSH THROUGH THE REGION LATE WEDNESDAY. AN INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT INTO THE
WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT
WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
THROUGH SUNRISE...STRATUS BUILD DOWN HAS RESULTED IN AREAS OF
DENSE FOG ACROSS MAINLY THE CHARLESTON TRI-COUNTY AREA EARLY THIS
MORNING. A DENSE FOG ADVISORY WILL BE ISSUED FOR THIS AREA UNTIL 9
AM FOR VSBYS 1/4 NM OR LESS. THERE IS A CHANCE THE FOG MAY LIFT
OR VSBYS IMPROVE ABOVE 1/4 MILE PRIOR TO 9 AM AS CONVECTION MOVING
OVER THE MIDLANDS COULD BRUSH PORTIONS OF THE TRI-COUNTY AREA...
BUT ITS UNCLEAR WHETHER THIS WILL HAPPEN. AREAS FARTHER TO THE
SOUTH ARE ALSO BEING MONITORED FOR POSSIBLE DENSE FOG...ESPECIALLY
OVER AREAS THAT SAW SIGNIFICANT RAINS MONDAY. AN EXPANSION OF THE
DENSE FOG ADVISORY MAY BE NEEDED OVER THE COMING HOURS.

TODAY...ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING.
WEAK SHORTWAVE ENERGY MOVING ACROSS THE CENTRAL PLAINS THIS
MORNING IS FORECAST TO MOVE QUICKLY EAST/SOUTHEAST TODAY...
APPROACHING THE SOUTHEAST U.S. THIS AFTERNOON. MODELS SHOW BROAD
DIFLUENCE DEVELOPING AHEAD OF THIS FEATURE WHILE THE RIGHT
ENTRANCE REGION OF YET ANOTHER 250 HPA JET STREAK PASSES OVERHEAD
DURING PEAK HEATING. A NORTHWEST FLOW ALOFT WILL RESULT IN THE
SEA BREEZE CIRCULATION BEING PINNED TO THE COAST FOR MUCH OF THE
DAY BEFORE SLOWLY SPREADING INLAND LATE. IT APPEARS CONVECTION
WILL LIKELY INITIATE THEN CONCENTRATE ALONG THE PINNED SEA BREEZE
CIRCULATION BY MID-AFTERNOON AND SPREAD VERY SLOWLY INLAND
COINCIDENT WITH THE SEA BREEZE ITSELF. SEVERAL HIGH RESOLUTION
MODELS SHOW A DISTINCT SIGNATURE THAT AN AREA OF CONCENTRATED
CONVECTION WILL CLUSTER IN THE SAVANNAH...DARIEN...SPRINGFIELD...
GLENNVILLE AREA BY MID-LATE AFTERNOON. THIS AREA OF CONVECTION
WILL POSE A RISK FOR FLASH FLOODING. SEE THE HYDROLOGY SECTION
BELOW FOR ADDITIONAL INFORMATION ON THE THREAT FOR HEAVY RAIN AND
FLOODING.

POPS WILL BE INCREASED SLIGHTLY ACROSS THE COASTAL ZONES THIS
AFTERNOON...RANGING FROM 60 PERCENT ACROSS THE CHARLESTON METRO
AREA TO 70 PERCENT FROM BEAUFORT AND SAVANNAH SOUTH...INCLUDING
AREAS SOUTH OF I-16. FATHER INLAND...MORE SCATTERED CONVECTION IS
EXPECTED...BUT WILL LIKELY BE A BIT MORE LOOSELY ORGANIZED. POPS
OF 30-50 PERCENT WILL BE MAINTAINED IN THIS AREA. HIGHS WILL TOP
OUT IN THE UPPER 80S INLAND WITH MID 80S AT THE BEACHES.


&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
TONIGHT...CONVECTION WILL QUICKLY WANE THIS EVENING WITH THE LOSS
OF INSOLATION. THE RISK FOR RAINFALL WILL GRADUALLY SHIFT OFFSHORE
CLOSER TO THE WESTERN WALL OF THE GULF STREAM AS A COLD FRONT
QUICKLY APPROACHES FROM THE NORTH. THE FRONT LOOKS TO REMAIN NORTH
AND NORTHWEST OF THE AREA THROUGH SUNRISE WEDNESDAY. SOME CLEARING
WILL LIKELY TAKE HOLD EARLY WEDNESDAY...ESPECIALLY ACROSS THE
WESTERN ZONES. WILL HAVE TO WATCH FOR POSSIBLE LOW STRATUS AND FOG
ONCE AGAIN GIVEN THE WET GROUNDS AND THE LIGHT WIND FIELDS THAT
WILL BE IN PLACE.

WEDNESDAY...THE SURFACE TROUGH WILL HAVE SHIFTED OFF THE SOUTHEAST
COASTLINE BY DAYBREAK...JUST DOWNSTREAM OF A SERIES OF SHORTWAVES
EMBEDDED WITHIN THE BASE OF A SHARPENING UPPER TROUGH AXIS.
PROGRESSION OF A STRONG COLD FRONT THROUGH THE FORECAST AREA
WILL LIKELY BE DELAYED UNTIL THE EVENING OR NIGHTTIME
PERIOD...WHEN A MORE DISTINCT AIR MASS CHANGE IS EVIDENT ALONG THE
LEADING EDGE OF STRONG HIGH PRESSURE BUILDING FROM THE
WEST/NORTHWEST. THE RIBBON OF DEEP LAYER MOISTURE RESPONSIBLE FOR
SEVERAL DAYS OF HEAVY RAIN EARLIER IN THE WEEK WILL HAVE MOVED TO
THE EAST/SOUTHEAST WITH THE SURFACE TROUGH. HOWEVER...THERE
APPEARS SUFFICIENT RESIDUAL MOISTURE TO SUPPORT SCATTERED
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON TIME
FRAME...ESPECIALLY AS SHORTWAVE ENERGY TRACKS THROUGH THE REGION
AND SEABREEZE DEVELOPMENT PROVIDES SOME FORCING/CONVERGENCE.
ISOLATED SHOWERS/THUNDERSTORMS COULD ACCOMPANY THE FRONT TOWARD
THE COASTLINE THROUGH MIDNIGHT...AND THEN EXPECT BEST RAIN CHANCES
TO SHIFT OVER THE MARINE ZONES DURING THE PRE-DAWN HOURS. HIGH
TEMPERATURES WILL ONCE AGAIN RISE ABOVE SEASONAL NORMALS WITHIN
DOWNSLOPE FLOW AND PRE-FRONTAL COMPRESSION...PEAKING IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES WILL
STILL BE A DEGREE OR TWO ABOVE NORMAL...YET TREND COOLER THAN
PREVIOUS NIGHTS BY FALLING INTO THE MID TO UPPER 60S.

THURSDAY AND FRIDAY...NORTHEAST FLOW DEVELOPING IN THE WAKE OF THE
FRONT AND WITHIN BUILDING HIGH PRESSURE FROM THE NORTH WILL
SUPPORT A NOTABLE COOLING TREND LATE IN THE WEEK. HIGH
TEMPERATURES ON THURSDAY WILL ONLY PEAK IN THE LOW TO MID
80S...WHILE ONLY RISING TO THE LOWER 80S FOR FRIDAY AFTERNOON.
NIGHTTIME LOW TEMPERATURES WILL ALSO REFLECT THE AIR MASS
CHANGE...AS LOWER DEWPOINTS/DRIER AIR ALLOW TEMPERATURES TO FALL
INTO THE LOW TO MID 60S. AS THE CENTER OF THE SURFACE HIGH TRACKS
FROM THE GREAT LAKES REGION THURSDAY AND INTO THE NEW ENGLAND
STATES FRIDAY...THE INLAND WEDGE WILL AMPLIFY DOWN THE
APPALACHIANS AND A COASTAL TROUGH WILL TAKE SHAPE ON THE SOUTHERN
COASTLINE. THIS PATTERN COULD ALLOW A DISTINCT GRADIENT IN
PRECIPITATION POTENTIAL BETWEEN THE DRIER INLAND AREAS AND COASTAL
COUNTIES NEAR CONVERGENCE ALONG THE TROUGH. RAIN COVERAGE WILL
STILL BE CONSIDERABLY LOWER THAN EARLIER IN THE WEEK FOR ALL
LOCATIONS...AND WILL ADVERTISE JUST ISOLATED SHOWERS/THUNDERSTORMS
INLAND AND SCATTERED ALONG THE COAST...MAINLY DURING THE AFTERNOON
PERIOD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LOW STRATUS AND FOG IS THE PRIMARY CONCERN THROUGH SUNRISE.

KCHS...CIGS/VSBYS HAVE ALREADY DROPPED AT KCHS...BUT CONDITIONS
HAVE BEEN BOUNCING AROUND. IFR CONDITIONS APPEAR LIKELY TO PERSIST
THROUGH SUNRISE AND MAY DROP TO PREVAILING LIFR. MAINTAINED TEMPO
LIFR CONDITIONS FOR NOW. VFR EXPECTED TO RETURN 13-15Z. CHANCES
FOR TSTMS THIS AFTERNOON APPEAR TO LOW RIGHT NOW TO JUSTIFY A
MENTION.

KSAV...VFR FOR NOW...BUT CONDITIONS ARE EXPECTED TO LOWER TO
PREVAILING IFR AFTER 09Z. THERE IS A CHANCE FOR LIFR
CONDITIONS...BUT ITS UNCLEAR AT THIS POINT WHETHER THAT WILL
OCCUR. AMENDMENTS MAY BE NEEDED. VFR BY 13-15Z WITH TSTM IMPACTS
POSSIBLE 19-22Z. LIMITED TSTM IMPACTS TO MVFR FOR NOW.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY...NEAR TERM CONCERNS CENTERS ON THE POTENTIAL FOR DENSE FOG
MOVING IN THE CHARLESTON HARBOR. HARBOR WEBCAMS SUGGEST CIGS ARE
SLOWLY LOWERING...BUT IT REMAINS UNCLEAR WHETHER VSBYS WILL DROP
ENOUGH PRIOR TO SUNRISE FOR A MARINE DENSE FOG ADVISORY. WILL
MAINTAIN A MENTION OF AREAS OF FOG FOR NOW AND CONTINUE TO MONITOR
TRENDS FOR A POSSIBLE MARINE DENSE FOG ADVISORY. OTHERWISE...LIGHT
WINDS WILL PERSIST AGAIN TODAY. LIGHT WEST/SOUTHWEST WINDS WILL
TURN MORE SOUTHERLY THIS AFTERNOON AS THE RESULTANT SEA BREEZE
TAKES HOLD. SPEEDS WILL REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT.

TONIGHT...LONG PERIOD SWELLS FROM HURRICANE EDOUARD WILL BEGIN TO
AFFECT THE WATERS WITH PERIODS OF 11-14 SECONDS. SEAS OF 1-2 FT
WILL BUILD TO 2-4 FT NEARSHORE WATERS AND 4-5 FT OFFSHORE WATERS.
ATTM IT APPEARS SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS...ALTHOUGH IT WILL BE CLOSE FOR THE GEORGIA OFFSHORE
WATERS.

WEDNESDAY AND THURSDAY...A COLD FRONT WILL PROGRESS INTO AND
THROUGH THE WATERS DURING THE MID WEEK PERIOD. LIGHT WINDS IN
ADVANCE OF THE FRONT WEDNESDAY WILL BECOME NORTH/NORTHEAST AND
INCREASE IN ITS WAKE BY THURSDAY. SEAS WILL BE COMPRISED MAINLY OF
LONG PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND
2 TO 4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS FAR OFFSHORE AND REMAINS FAIRLY
STATIONARY ALONG THE PERIPHERY OF AN INLAND WEDGE OF HIGH
PRESSURE. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE FOR
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...BEFORE
CONDITIONS MODERATE WITHIN A TRANSITIONING PATTERN BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL
ARRIVE AT THE BEACHES LATE THIS AFTERNOON AND CONTINUE INTO
THURSDAY. THERE DOES NOT APPEAR TO BE MUCH MORE THAN ABOUT 1 FT
SWELL THAT MAKES IT TO THE BEACHES BY LATE AFTERNOON...SO THE RIP
CURRENT RISK WILL REMAIN IN THE LOW CATEGORY FOR TODAY. LARGER
SWELLS AROUND 3 FT WILL OCCUR WEDNESDAY INTO THURSDAY AND THIS
WILL LEAD TO AN ENHANCED RISK OF RIP CURRENTS. FOR FRIDAY THROUGH
SUNDAY SWELL FROM EDOUARD WILL DIMINISH...BUT STRONGER NE WINDS
WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK OF RIP CURRENTS
TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING. HIGH
RESOLUTION MODELS ARE SHOWING A DISTINCT SIGNAL THAT AN AREA OF
HEAVY RAIN WILL SETUP IN THE AREA FROM SAVANNAH SOUTH TO DARIEN
AND OVER TO SPRINGFIELD AND GLENNVILLE FOR SEVERAL HOURS THIS
AFTERNOON ALONG A PINNED SEA BREEZE CIRCULATION. ALTHOUGH STORM
MOTIONS WILL BE FASTER THAN PREVIOUS DAYS...THE POTENTIAL FOR
NUMEROUS MESOSCALE BOUNDARY INTERACTIONS...STRONG UPPER DIVERGENCE
AND HIGH PWAT VALUES NEAR THE 99TH PERCENTILE SUGGEST THERE IS A
HIGH POTENTIAL FOR EXCESSIVE HOURLY RAINFALL RATES EXCEEDING 2-3
IN/HR...WHICH IS HIGHER THAN THE LATEST 1-HR FLASH FLOOD GUIDANCE.
IN ADDITION...SOME AREAS HAVE ALREADY SEEN IN EXCESS OF 6 INCHES
OVER THE PAST FEW DAYS.

A FLASH FLOOD WATCH WILL BE ISSUED FOR AREAS SOUTH OF I-16 IN
SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH CAROLINA
THROUGH 8 PM EDT AS THESE AREAS HAVE THE HIGHEST POTENTIAL FOR
FLASH FLOODING TODAY. THE COASTAL SOUTH CAROLINA ZONES WILL BE
INCLUDED IN THE WATCH MAINLY TO ACCOUNT FOR POSSIBLE HEAVY RAIN
FALLING AROUND HIGH TIDE THIS AFTERNOON. SIMILAR TO THE PAST FEW
DAYS...ISOLATED RAIN AMOUNTS IN EXCESS OF 5 INCHES WILL BE
POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ048>052.
     DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ044-045-
     050-052.
MARINE...NONE.

&&

$$

ST/WMS






000
FXUS62 KCHS 160747
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
347 AM EDT TUE SEP 16 2014

...ONE LAST DAY OF HEAVY RAIN AND POSSIBLE FLASH FLOODING...

.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND
PUSH THROUGH THE REGION LATE WEDNESDAY. AN INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN THE WAKE OF THE FRONT INTO THE
WEEKEND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST EARLY NEXT
WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
THROUGH SUNRISE...STRATUS BUILD DOWN HAS RESULTED IN AREAS OF
DENSE FOG ACROSS MAINLY THE CHARLESTON TRI-COUNTY AREA EARLY THIS
MORNING. A DENSE FOG ADVISORY WILL BE ISSUED FOR THIS AREA UNTIL 9
AM FOR VSBYS 1/4 NM OR LESS. THERE IS A CHANCE THE FOG MAY LIFT
OR VSBYS IMPROVE ABOVE 1/4 MILE PRIOR TO 9 AM AS CONVECTION MOVING
OVER THE MIDLANDS COULD BRUSH PORTIONS OF THE TRI-COUNTY AREA...
BUT ITS UNCLEAR WHETHER THIS WILL HAPPEN. AREAS FARTHER TO THE
SOUTH ARE ALSO BEING MONITORED FOR POSSIBLE DENSE FOG...ESPECIALLY
OVER AREAS THAT SAW SIGNIFICANT RAINS MONDAY. AN EXPANSION OF THE
DENSE FOG ADVISORY MAY BE NEEDED OVER THE COMING HOURS.

TODAY...ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING.
WEAK SHORTWAVE ENERGY MOVING ACROSS THE CENTRAL PLAINS THIS
MORNING IS FORECAST TO MOVE QUICKLY EAST/SOUTHEAST TODAY...
APPROACHING THE SOUTHEAST U.S. THIS AFTERNOON. MODELS SHOW BROAD
DIFLUENCE DEVELOPING AHEAD OF THIS FEATURE WHILE THE RIGHT
ENTRANCE REGION OF YET ANOTHER 250 HPA JET STREAK PASSES OVERHEAD
DURING PEAK HEATING. A NORTHWEST FLOW ALOFT WILL RESULT IN THE
SEA BREEZE CIRCULATION BEING PINNED TO THE COAST FOR MUCH OF THE
DAY BEFORE SLOWLY SPREADING INLAND LATE. IT APPEARS CONVECTION
WILL LIKELY INITIATE THEN CONCENTRATE ALONG THE PINNED SEA BREEZE
CIRCULATION BY MID-AFTERNOON AND SPREAD VERY SLOWLY INLAND
COINCIDENT WITH THE SEA BREEZE ITSELF. SEVERAL HIGH RESOLUTION
MODELS SHOW A DISTINCT SIGNATURE THAT AN AREA OF CONCENTRATED
CONVECTION WILL CLUSTER IN THE SAVANNAH...DARIEN...SPRINGFIELD...
GLENNVILLE AREA BY MID-LATE AFTERNOON. THIS AREA OF CONVECTION
WILL POSE A RISK FOR FLASH FLOODING. SEE THE HYDROLOGY SECTION
BELOW FOR ADDITIONAL INFORMATION ON THE THREAT FOR HEAVY RAIN AND
FLOODING.

POPS WILL BE INCREASED SLIGHTLY ACROSS THE COASTAL ZONES THIS
AFTERNOON...RANGING FROM 60 PERCENT ACROSS THE CHARLESTON METRO
AREA TO 70 PERCENT FROM BEAUFORT AND SAVANNAH SOUTH...INCLUDING
AREAS SOUTH OF I-16. FATHER INLAND...MORE SCATTERED CONVECTION IS
EXPECTED...BUT WILL LIKELY BE A BIT MORE LOOSELY ORGANIZED. POPS
OF 30-50 PERCENT WILL BE MAINTAINED IN THIS AREA. HIGHS WILL TOP
OUT IN THE UPPER 80S INLAND WITH MID 80S AT THE BEACHES.


&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
TONIGHT...CONVECTION WILL QUICKLY WANE THIS EVENING WITH THE LOSS
OF INSOLATION. THE RISK FOR RAINFALL WILL GRADUALLY SHIFT OFFSHORE
CLOSER TO THE WESTERN WALL OF THE GULF STREAM AS A COLD FRONT
QUICKLY APPROACHES FROM THE NORTH. THE FRONT LOOKS TO REMAIN NORTH
AND NORTHWEST OF THE AREA THROUGH SUNRISE WEDNESDAY. SOME CLEARING
WILL LIKELY TAKE HOLD EARLY WEDNESDAY...ESPECIALLY ACROSS THE
WESTERN ZONES. WILL HAVE TO WATCH FOR POSSIBLE LOW STRATUS AND FOG
ONCE AGAIN GIVEN THE WET GROUNDS AND THE LIGHT WIND FIELDS THAT
WILL BE IN PLACE.

WEDNESDAY...THE SURFACE TROUGH WILL HAVE SHIFTED OFF THE SOUTHEAST
COASTLINE BY DAYBREAK...JUST DOWNSTREAM OF A SERIES OF SHORTWAVES
EMBEDDED WITHIN THE BASE OF A SHARPENING UPPER TROUGH AXIS.
PROGRESSION OF A STRONG COLD FRONT THROUGH THE FORECAST AREA
WILL LIKELY BE DELAYED UNTIL THE EVENING OR NIGHTTIME
PERIOD...WHEN A MORE DISTINCT AIR MASS CHANGE IS EVIDENT ALONG THE
LEADING EDGE OF STRONG HIGH PRESSURE BUILDING FROM THE
WEST/NORTHWEST. THE RIBBON OF DEEP LAYER MOISTURE RESPONSIBLE FOR
SEVERAL DAYS OF HEAVY RAIN EARLIER IN THE WEEK WILL HAVE MOVED TO
THE EAST/SOUTHEAST WITH THE SURFACE TROUGH. HOWEVER...THERE
APPEARS SUFFICIENT RESIDUAL MOISTURE TO SUPPORT SCATTERED
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON TIME
FRAME...ESPECIALLY AS SHORTWAVE ENERGY TRACKS THROUGH THE REGION
AND SEABREEZE DEVELOPMENT PROVIDES SOME FORCING/CONVERGENCE.
ISOLATED SHOWERS/THUNDERSTORMS COULD ACCOMPANY THE FRONT TOWARD
THE COASTLINE THROUGH MIDNIGHT...AND THEN EXPECT BEST RAIN CHANCES
TO SHIFT OVER THE MARINE ZONES DURING THE PRE-DAWN HOURS. HIGH
TEMPERATURES WILL ONCE AGAIN RISE ABOVE SEASONAL NORMALS WITHIN
DOWNSLOPE FLOW AND PRE-FRONTAL COMPRESSION...PEAKING IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. LOW TEMPERATURES WILL
STILL BE A DEGREE OR TWO ABOVE NORMAL...YET TREND COOLER THAN
PREVIOUS NIGHTS BY FALLING INTO THE MID TO UPPER 60S.

THURSDAY AND FRIDAY...NORTHEAST FLOW DEVELOPING IN THE WAKE OF THE
FRONT AND WITHIN BUILDING HIGH PRESSURE FROM THE NORTH WILL
SUPPORT A NOTABLE COOLING TREND LATE IN THE WEEK. HIGH
TEMPERATURES ON THURSDAY WILL ONLY PEAK IN THE LOW TO MID
80S...WHILE ONLY RISING TO THE LOWER 80S FOR FRIDAY AFTERNOON.
NIGHTTIME LOW TEMPERATURES WILL ALSO REFLECT THE AIR MASS
CHANGE...AS LOWER DEWPOINTS/DRIER AIR ALLOW TEMPERATURES TO FALL
INTO THE LOW TO MID 60S. AS THE CENTER OF THE SURFACE HIGH TRACKS
FROM THE GREAT LAKES REGION THURSDAY AND INTO THE NEW ENGLAND
STATES FRIDAY...THE INLAND WEDGE WILL AMPLIFY DOWN THE
APPALACHIANS AND A COASTAL TROUGH WILL TAKE SHAPE ON THE SOUTHERN
COASTLINE. THIS PATTERN COULD ALLOW A DISTINCT GRADIENT IN
PRECIPITATION POTENTIAL BETWEEN THE DRIER INLAND AREAS AND COASTAL
COUNTIES NEAR CONVERGENCE ALONG THE TROUGH. RAIN COVERAGE WILL
STILL BE CONSIDERABLY LOWER THAN EARLIER IN THE WEEK FOR ALL
LOCATIONS...AND WILL ADVERTISE JUST ISOLATED SHOWERS/THUNDERSTORMS
INLAND AND SCATTERED ALONG THE COAST...MAINLY DURING THE AFTERNOON
PERIOD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE INLAND AND A COASTAL TROUGH WILL
CONTROL THE PATTERN THROUGH SATURDAY...BEFORE BREAKING DOWN SUNDAY
AHEAD OF ANOTHER STRONG COLD FRONT APPROACHING EARLY NEXT WEEK.
EXPECT BEST RAIN CHANCES TO BE FOUND ALONG THE COAST AND OVER THE
MARINE ZONES THROUGH THE WEEKEND...AS THESE LOCATIONS WILL BE
CLOSEST TO MOISTURE AND CONVERGENCE ASSOCIATED WITH THE COASTAL
TROUGH. HIGH TEMPERATURES WILL ONCE AGAIN BE SUPPRESSED IN THE
LOWER 80S FOR SATURDAY AFTERNOON...BEFORE CONDITIONS BEGIN TO
MODERATE SUNDAY AS THE INLAND WEDGE PATTERN WEAKENS. MEDIUM RANGE
MODELS ARE SUGGESTING THAT THE NEXT COLD FRONT COULD MOVE THROUGH
THE REGION BY TUESDAY...YET ARE NOT INDICATING A SUBSTANTIAL
AMOUNT OF PRECIPITATION ASSOCIATED WITH ITS PROGRESSION. WILL THUS
REMAIN RATHER CONSERVATIVE WITH RAIN CHANCES TOWARD THE END OF THE
FORECAST PERIOD...CAPPING POPS IN THE SLIGHT CHANCE TO LOW CHANCE
RANGE FOR MONDAY AND TUESDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LOW STRATUS AND FOG IS THE PRIMARY CONCERN THROUGH SUNRISE.

KCHS...CIGS/VSBYS HAVE ALREADY DROPPED AT KCHS...BUT CONDITIONS
HAVE BEEN BOUNCING AROUND. IFR CONDITIONS APPEAR LIKELY TO PERSIST
THROUGH SUNRISE AND MAY DROP TO PREVAILING LIFR. MAINTAINED TEMPO
LIFR CONDITIONS FOR NOW. VFR EXPECTED TO RETURN 13-15Z. CHANCES
FOR TSTMS THIS AFTERNOON APPEAR TO LOW RIGHT NOW TO JUSTIFY A
MENTION.

KSAV...VFR FOR NOW...BUT CONDITIONS ARE EXPECTED TO LOWER TO
PREVAILING IFR AFTER 09Z. THERE IS A CHANCE FOR LIFR
CONDITIONS...BUT ITS UNCLEAR AT THIS POINT WHETHER THAT WILL
OCCUR. AMENDMENTS MAY BE NEEDED. VFR BY 13-15Z WITH TSTM IMPACTS
POSSIBLE 19-22Z. LIMITED TSTM IMPACTS TO MVFR FOR NOW.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY...NEAR TERM CONCERNS CENTERS ON THE POTENTIAL FOR DENSE FOG
MOVING IN THE CHARLESTON HARBOR. HARBOR WEBCAMS SUGGEST CIGS ARE
SLOWLY LOWERING...BUT IT REMAINS UNCLEAR WHETHER VSBYS WILL DROP
ENOUGH PRIOR TO SUNRISE FOR A MARINE DENSE FOG ADVISORY. WILL
MAINTAIN A MENTION OF AREAS OF FOG FOR NOW AND CONTINUE TO MONITOR
TRENDS FOR A POSSIBLE MARINE DENSE FOG ADVISORY. OTHERWISE...LIGHT
WINDS WILL PERSIST AGAIN TODAY. LIGHT WEST/SOUTHWEST WINDS WILL
TURN MORE SOUTHERLY THIS AFTERNOON AS THE RESULTANT SEA BREEZE
TAKES HOLD. SPEEDS WILL REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT.

TONIGHT...LONG PERIOD SWELLS FROM HURRICANE EDOUARD WILL BEGIN TO
AFFECT THE WATERS WITH PERIODS OF 11-14 SECONDS. SEAS OF 1-2 FT
WILL BUILD TO 2-4 FT NEARSHORE WATERS AND 4-5 FT OFFSHORE WATERS.
ATTM IT APPEARS SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS...ALTHOUGH IT WILL BE CLOSE FOR THE GEORGIA OFFSHORE
WATERS.

WEDNESDAY AND THURSDAY...A COLD FRONT WILL PROGRESS INTO AND
THROUGH THE WATERS DURING THE MID WEEK PERIOD. LIGHT WINDS IN
ADVANCE OF THE FRONT WEDNESDAY WILL BECOME NORTH/NORTHEAST AND
INCREASE IN ITS WAKE BY THURSDAY. SEAS WILL BE COMPRISED MAINLY OF
LONG PERIOD SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD...AROUND
2 TO 4 FT WITHIN 20 NM AND 3 TO 5 FT FARTHER OFFSHORE.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS FAR OFFSHORE AND REMAINS FAIRLY
STATIONARY ALONG THE PERIPHERY OF AN INLAND WEDGE OF HIGH
PRESSURE. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE FOR
PORTIONS OF THE MARINE ZONES FRIDAY AND SATURDAY...BEFORE
CONDITIONS MODERATE WITHIN A TRANSITIONING PATTERN BY SUNDAY.

RIP CURRENTS...LONG PERIOD SWELL FROM HURRICANE EDOUARD WILL
ARRIVE AT THE BEACHES LATE THIS AFTERNOON AND CONTINUE INTO
THURSDAY. THERE DOES NOT APPEAR TO BE MUCH MORE THAN ABOUT 1 FT
SWELL THAT MAKES IT TO THE BEACHES BY LATE AFTERNOON...SO THE RIP
CURRENT RISK WILL REMAIN IN THE LOW CATEGORY FOR TODAY. LARGER
SWELLS AROUND 3 FT WILL OCCUR WEDNESDAY INTO THURSDAY AND THIS
WILL LEAD TO AN ENHANCED RISK OF RIP CURRENTS. FOR FRIDAY THROUGH
SUNDAY SWELL FROM EDOUARD WILL DIMINISH...BUT STRONGER NE WINDS
WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK OF RIP CURRENTS
TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ONE MORE DAY FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING. HIGH
RESOLUTION MODELS ARE SHOWING A DISTINCT SIGNAL THAT AN AREA OF
HEAVY RAIN WILL SETUP IN THE AREA FROM SAVANNAH SOUTH TO DARIEN
AND OVER TO SPRINGFIELD AND GLENNVILLE FOR SEVERAL HOURS THIS
AFTERNOON ALONG A PINNED SEA BREEZE CIRCULATION. ALTHOUGH STORM
MOTIONS WILL BE FASTER THAN PREVIOUS DAYS...THE POTENTIAL FOR
NUMEROUS MESOSCALE BOUNDARY INTERACTIONS...STRONG UPPER DIVERGENCE
AND HIGH PWAT VALUES NEAR THE 99TH PERCENTILE SUGGEST THERE IS A
HIGH POTENTIAL FOR EXCESSIVE HOURLY RAINFALL RATES EXCEEDING 2-3
IN/HR...WHICH IS HIGHER THAN THE LATEST 1-HR FLASH FLOOD GUIDANCE.
IN ADDITION...SOME AREAS HAVE ALREADY SEEN IN EXCESS OF 6 INCHES
OVER THE PAST FEW DAYS.

A FLASH FLOOD WATCH WILL BE ISSUED FOR AREAS SOUTH OF I-16 IN
SOUTHEAST GEORGIA AND THE COASTAL ZONES OF SOUTHERN SOUTH CAROLINA
THROUGH 8 PM EDT AS THESE AREAS HAVE THE HIGHEST POTENTIAL FOR
FLASH FLOODING TODAY. THE COASTAL SOUTH CAROLINA ZONES WILL BE
INCLUDED IN THE WATCH MAINLY TO ACCOUNT FOR POSSIBLE HEAVY RAIN
FALLING AROUND HIGH TIDE THIS AFTERNOON. SIMILAR TO THE PAST FEW
DAYS...ISOLATED RAIN AMOUNTS IN EXCESS OF 5 INCHES WILL BE
POSSIBLE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ048>052.
     DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ044-045-
     050-052.
MARINE...NONE.

&&

$$

ST/WMS





000
FXUS62 KCHS 160454
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1254 AM EDT TUE SEP 16 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST
TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A STRONG
INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE
FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MAIN CONCERNS THROUGH SUNRISE IS THE POTENTIAL FOR STRATUS AND
FOG. VSBYS HAVE ALREADY DROPPED ACROSS MUCH OF THE CHARLESTON TRI-
COUNTY AREA WHERE THE FOG HAS BECOME LOCALLY DENSE AT TIMES. A
SPECIAL WEATHER STATEMENT HAS BEEN ISSUED TO COVER. ITS UNCLEAR
EXACTLY HOW WIDESPREAD THE STRATUS AND FOG WILL BECOME NOW THAT
THE WEDGE FRONT IS TO THE NORTH...BUT WET GROUNDS AND LIGHT WINDS
CERTAINLY SUGGEST THE RISK IS RATHER ELEVATED. A DENSE FOG
ADVISORY MAY BE NEEDED FOR SOME AREAS PRIOR TO SUNRISE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LOW STRATUS AND FOG IS THE PRIMARY CONCERN THROUGH SUNRISE.

KCHS...CIGS/VSBYS HAVE ALREADY DROPPED AT KCHS...BUT CONDITIONS
HAVE BEEN BOUNCING AROUND. IFR CONDITIONS APPEAR LIKELY TO PERSIST
THROUGH SUNRISE AND MAY DROP TO PREVAILING LIFR. MAINTAINED TEMPO
LIFR CONDITIONS FOR NOW. VFR EXPECTED TO RETURN 13-15Z. CHANCES
FOR TSTMS THIS AFTERNOON APPEAR TO LOW RIGHT NOW TO JUSTIFY A
MENTION.

KSAV...VFR FOR NOW...BUT CONDITIONS ARE EXPECTED TO LOWER TO
PREVAILING IFR AFTER 09Z. THERE IS A CHANCE FOR LIFR
CONDITIONS...BUT ITS UNCLEAR AT THIS POINT WHETHER THAT WILL
OCCUR. AMENDMENTS MAY BE NEEDED. VFR BY 13-15Z WITH TSTM IMPACTS
POSSIBLE 19-22Z. LIMITED TSTM IMPACTS TO MVFR FOR NOW.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
OVERNIGHT...A WEAK PRESSURE GRADIENT WILL SUPPORT WINDS 10 KT
OR LESS. WIND DIRECTION WILL CHANGE FROM EAST TO SOUTH...THEN WILL
TURN TO THE WEST TOWARD DAYBREAK. THUNDERSTORMS AND ASSOCIATED
OUTFLOW WILL ALSO ALTER LOCAL WIND DIRECTION/SPEED. SEAS 1 TO 2 FT
WILL PREVAIL.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOES NOT APPEAR TO BE MUCH MORE THAN
ABOUT 2 FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO
WILL KEEP THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER
SWELLS AROUND 3 FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS
MAY LEAD TO AN ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ANOTHER ROUND OF SLOW-MOVING SHOWERS AND THUNDERSTORMS WITH A
THREAT FOR LOCALLY EXCESSIVE RAINFALL IS POSSIBLE MAINLY
ALONG/SOUTH OF INTERSTATE 16 TUESDAY.

&&

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

&&

$$

ST





000
FXUS62 KCHS 160454
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1254 AM EDT TUE SEP 16 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST
TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A STRONG
INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE
FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MAIN CONCERNS THROUGH SUNRISE IS THE POTENTIAL FOR STRATUS AND
FOG. VSBYS HAVE ALREADY DROPPED ACROSS MUCH OF THE CHARLESTON TRI-
COUNTY AREA WHERE THE FOG HAS BECOME LOCALLY DENSE AT TIMES. A
SPECIAL WEATHER STATEMENT HAS BEEN ISSUED TO COVER. ITS UNCLEAR
EXACTLY HOW WIDESPREAD THE STRATUS AND FOG WILL BECOME NOW THAT
THE WEDGE FRONT IS TO THE NORTH...BUT WET GROUNDS AND LIGHT WINDS
CERTAINLY SUGGEST THE RISK IS RATHER ELEVATED. A DENSE FOG
ADVISORY MAY BE NEEDED FOR SOME AREAS PRIOR TO SUNRISE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LOW STRATUS AND FOG IS THE PRIMARY CONCERN THROUGH SUNRISE.

KCHS...CIGS/VSBYS HAVE ALREADY DROPPED AT KCHS...BUT CONDITIONS
HAVE BEEN BOUNCING AROUND. IFR CONDITIONS APPEAR LIKELY TO PERSIST
THROUGH SUNRISE AND MAY DROP TO PREVAILING LIFR. MAINTAINED TEMPO
LIFR CONDITIONS FOR NOW. VFR EXPECTED TO RETURN 13-15Z. CHANCES
FOR TSTMS THIS AFTERNOON APPEAR TO LOW RIGHT NOW TO JUSTIFY A
MENTION.

KSAV...VFR FOR NOW...BUT CONDITIONS ARE EXPECTED TO LOWER TO
PREVAILING IFR AFTER 09Z. THERE IS A CHANCE FOR LIFR
CONDITIONS...BUT ITS UNCLEAR AT THIS POINT WHETHER THAT WILL
OCCUR. AMENDMENTS MAY BE NEEDED. VFR BY 13-15Z WITH TSTM IMPACTS
POSSIBLE 19-22Z. LIMITED TSTM IMPACTS TO MVFR FOR NOW.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
OVERNIGHT...A WEAK PRESSURE GRADIENT WILL SUPPORT WINDS 10 KT
OR LESS. WIND DIRECTION WILL CHANGE FROM EAST TO SOUTH...THEN WILL
TURN TO THE WEST TOWARD DAYBREAK. THUNDERSTORMS AND ASSOCIATED
OUTFLOW WILL ALSO ALTER LOCAL WIND DIRECTION/SPEED. SEAS 1 TO 2 FT
WILL PREVAIL.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOES NOT APPEAR TO BE MUCH MORE THAN
ABOUT 2 FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO
WILL KEEP THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER
SWELLS AROUND 3 FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS
MAY LEAD TO AN ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ANOTHER ROUND OF SLOW-MOVING SHOWERS AND THUNDERSTORMS WITH A
THREAT FOR LOCALLY EXCESSIVE RAINFALL IS POSSIBLE MAINLY
ALONG/SOUTH OF INTERSTATE 16 TUESDAY.

&&

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

&&

$$

ST






000
FXUS62 KCHS 160139
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
939 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST
TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A STRONG
INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE
FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
DISCONTINUED THE FLASH FLOOD WATCH FOR SC COUNTIES FROM COLLETON
TO THE SANTEE RIVER.

LATE MONDAY EVENING...ADJUSTED FORECASTS TO ACCOUNT FOR
ONGOING/EXPECTED RADAR TRENDS. FOR THE NEXT FEW HOURS...SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS DEVELOPING/DISSIPATING ALONG VARIOUS
MESOSCALE BOUNDARIES FROM COLLETON COUNTY NE TO THE SANTEE RIVER
SHOULD GRADUALLY DIMINISH IN COVERAGE. ALSO...SCATTERED TO LOCALLY
NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS SHOULD PUSH THROUGH AREAS
MAINLY SOUTH OF I-16. HERE TOO...COVERAGE OF CONVECTION SHOULD
GRADUALLY WIND DOWN OVERNIGHT. ELSEWHERE...EXPECTED NOTHING MORE
THAN ISOLATED SHOWERS/THUNDERSTORMS.

OVERNIGHT...HIGHEST POPS CAPPED AT 30 TO 50 PERCENT SHOULD SHIFT
INTO AREAS ALONG/EAST OF I-95 AND ADJACENT COASTAL WATERS AS LOW
LEVEL WINDS TURN TOWARD THE WEST.

GIVEN PWATS AROUND 2.3 INCHES AS DEPICTED BY THE 00Z KCHS RAOB...
LOCALLY HEAVY RAINFALL IS STILL POSSIBLE IN ANY
SHOWERS/THUNDERSTORMS TONIGHT. HOWEVER...THE THREAT FOR FLASH
FLOODING HAS DIMINISHED.

STRATUS COULD ONCE AGAIN DEVELOP AND LOWER TO THE SURFACE LATE
TONIGHT...THUS FORECASTS INCLUDE AREAS OF FOG.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR UNTIL AFTER 06Z. THEN...LOW LEVEL MOISTURE WILL
SUPPORT AT LEAST MVFR/IFR CONDITIONS LATE TONIGHT INTO TUESDAY
MORNING...AND LIFR CONDITIONS ARE POSSIBLE. AS USUAL...THE TIMING
AND DEGREE OF DETERIORATION REMAIN UNCERTAIN... AND AMENDMENTS/
ADJUSTMENTS COULD BE REQUIRED WITHIN SUBSEQUENT FORECASTS
OVERNIGHT. THEN...THUNDERSTORMS ARE AGAIN EXPECTED IN THE VICINITY
OF THE TERMINALS TUESDAY AFTERNOON...AND DIRECT IMPACTS ARE LIKELY
AT KSAV.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
OVERNIGHT...A WEAK PRESSURE GRADIENT WILL SUPPORT WINDS 10 KT
OR LESS. WIND DIRECTION WILL CHANGE FROM EAST TO SOUTH...THEN WILL
TURN TO THE WEST TOWARD DAYBREAK. THUNDERSTORMS AND ASSOCIATED
OUTFLOW WILL ALSO ALTER LOCAL WIND DIRECTION/SPEED. SEAS 1 TO 2 FT
WILL PREVAIL.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOESN/T APPEAR TO BE MUCH MORE THAN ABOUT 2
FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO WILL KEEP
THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER SWELLS AROUND 3
FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS MAY LEAD TO AN
ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ANOTHER ROUND OF SLOW-MOVING SHOWERS AND THUNDERSTORMS WITH A
THREAT FOR LOCALLY EXCESSIVE RAINFALL IS POSSIBLE MAINLY
ALONG/SOUTH OF INTERSTATE 16 TUESDAY.

&&

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

&&

$$

NEAR TERM...SPR
SHORT TERM...
LONG TERM...
AVIATION...SPR
MARINE...SPR
HYDROLOGY...







000
FXUS62 KCHS 160139
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
939 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST
TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A STRONG
INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE
FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
DISCONTINUED THE FLASH FLOOD WATCH FOR SC COUNTIES FROM COLLETON
TO THE SANTEE RIVER.

LATE MONDAY EVENING...ADJUSTED FORECASTS TO ACCOUNT FOR
ONGOING/EXPECTED RADAR TRENDS. FOR THE NEXT FEW HOURS...SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS DEVELOPING/DISSIPATING ALONG VARIOUS
MESOSCALE BOUNDARIES FROM COLLETON COUNTY NE TO THE SANTEE RIVER
SHOULD GRADUALLY DIMINISH IN COVERAGE. ALSO...SCATTERED TO LOCALLY
NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS SHOULD PUSH THROUGH AREAS
MAINLY SOUTH OF I-16. HERE TOO...COVERAGE OF CONVECTION SHOULD
GRADUALLY WIND DOWN OVERNIGHT. ELSEWHERE...EXPECTED NOTHING MORE
THAN ISOLATED SHOWERS/THUNDERSTORMS.

OVERNIGHT...HIGHEST POPS CAPPED AT 30 TO 50 PERCENT SHOULD SHIFT
INTO AREAS ALONG/EAST OF I-95 AND ADJACENT COASTAL WATERS AS LOW
LEVEL WINDS TURN TOWARD THE WEST.

GIVEN PWATS AROUND 2.3 INCHES AS DEPICTED BY THE 00Z KCHS RAOB...
LOCALLY HEAVY RAINFALL IS STILL POSSIBLE IN ANY
SHOWERS/THUNDERSTORMS TONIGHT. HOWEVER...THE THREAT FOR FLASH
FLOODING HAS DIMINISHED.

STRATUS COULD ONCE AGAIN DEVELOP AND LOWER TO THE SURFACE LATE
TONIGHT...THUS FORECASTS INCLUDE AREAS OF FOG.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR UNTIL AFTER 06Z. THEN...LOW LEVEL MOISTURE WILL
SUPPORT AT LEAST MVFR/IFR CONDITIONS LATE TONIGHT INTO TUESDAY
MORNING...AND LIFR CONDITIONS ARE POSSIBLE. AS USUAL...THE TIMING
AND DEGREE OF DETERIORATION REMAIN UNCERTAIN... AND AMENDMENTS/
ADJUSTMENTS COULD BE REQUIRED WITHIN SUBSEQUENT FORECASTS
OVERNIGHT. THEN...THUNDERSTORMS ARE AGAIN EXPECTED IN THE VICINITY
OF THE TERMINALS TUESDAY AFTERNOON...AND DIRECT IMPACTS ARE LIKELY
AT KSAV.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
OVERNIGHT...A WEAK PRESSURE GRADIENT WILL SUPPORT WINDS 10 KT
OR LESS. WIND DIRECTION WILL CHANGE FROM EAST TO SOUTH...THEN WILL
TURN TO THE WEST TOWARD DAYBREAK. THUNDERSTORMS AND ASSOCIATED
OUTFLOW WILL ALSO ALTER LOCAL WIND DIRECTION/SPEED. SEAS 1 TO 2 FT
WILL PREVAIL.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOESN/T APPEAR TO BE MUCH MORE THAN ABOUT 2
FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO WILL KEEP
THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER SWELLS AROUND 3
FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS MAY LEAD TO AN
ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
ANOTHER ROUND OF SLOW-MOVING SHOWERS AND THUNDERSTORMS WITH A
THREAT FOR LOCALLY EXCESSIVE RAINFALL IS POSSIBLE MAINLY
ALONG/SOUTH OF INTERSTATE 16 TUESDAY.

&&

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

&&

$$

NEAR TERM...SPR
SHORT TERM...
LONG TERM...
AVIATION...SPR
MARINE...SPR
HYDROLOGY...








000
FXUS62 KCHS 152322
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
722 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
THROUGH TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE
NORTHWEST TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A
STRONG INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF
THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WE/VE SEEN PLENTY OF WATER IN THE CHARLESTON TRI-COUNTY AREA THAT
OCCURRED UNFORTUNATELY AROUND THE TIME OF RUSH HOUR...BUT
FORTUNATELY DURING AN OUTGOING TIDE. MUCH OF THIS ACTIVITY APPEARS
TO BE IN A DIMINISHING MODE...BUT UNTIL IT DOES SO WE WILL HOLD
ONTO THE FLASH FLOOD WATCH FOR THE CHARLESTON TRI-COUNTY REGION.

FURTHER TO THE SOUTH THERE IS A CONSOLIDATING AREA OF INTENSE
RAINS SOUTH OF THE ALTAMAHA RIVER THAT HAS DEVELOPED IN
CONJUNCTION WITH THE SEA BREEZE DRIVING NE FROM THE GULF AND
VARIOUS MESO-SCALE BOUNDARIES. ODDS FAVOR THAT THIS CONVECTION
WILL GENERALLY STRUGGLE TO MAKE IT INTO THE CWFA...BUT WE COULD
STILL SEE SOME LOCALLY HEAVY RAINS DOWN NEAR THE ALTAMAHA THROUGH
THIS EVENING. EVEN SO AFTER A METEOROLOGICAL CONSULTATION WE HAVE
OPTED TO CANCEL THE FLASH FLOOD WATCH FOR THESE COUNTIES AND ALL
OTHER COUNTIES OUTSIDE THE CHARLESTON QUAD-COUNTY REGION.

THE DIURNAL TEMP CURVE HAS BEEN CORRUPTED BY THE CONVECTION...BUT
WILL STABILIZE LATER THIS EVENING...THEN HEADING DOWN TO LATE NIGHT
LOWS IN THE 70 TO 75 DEGREE RANGE...LOWEST INLAND AND WARMEST ON
THE ISLAND COMMUNITIES.

WHILE NOT OVERLY CONFIDENT ON SUCH AN OCCURRENCES...MODEL
SOUNDINGS SUGGEST SOME BUILDING DOWN OF STRATUS AND GIVEN THE
RAINFALL TODAY AND YESTERDAY THE GROUNDS IN MANY AREAS ARE QUITE
SATURATED. THIS SHOULD LEAD TO AT LEAST PATCHY FOG LATE TONIGHT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
EXCEPT FOR CIG/VISIBILITY RESTRICTIONS IN SHRA AT KCHS EARLY THIS
EVENING...MAINLY VFR UNTIL AFTER 06Z. THEN...LOW LEVEL MOISTURE
WILL SUPPORT AT LEAST MVFR/IFR CONDITIONS LATE TONIGHT INTO
TUESDAY MORNING...AND LIFR CONDITIONS ARE POSSIBLE. AS
USUAL...THE TIMING AND DEGREE OF DETERIORATION REMAIN UNCERTAIN...
AND AMENDMENTS/ADJUSTMENTS COULD BE REQUIRED WITHIN SUBSEQUENT
FORECASTS TONIGHT. THEN...THUNDERSTORMS ARE AGAIN EXPECTED IN THE
VICINITY OF THE TERMINALS TUESDAY AFTERNOON...AND DIRECT IMPACTS
ARE LIKELY AT KSAV.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TONIGHT...WINDS ARE BEING DRIVEN MAINLY BY LINGERING SEA BREEZE
CIRCULATIONS THIS EVENING. A WEAK SYNOPTIC SCENARIO FOR THE REST OF
THE NIGHT WILL ALLOW FOR LAND BREEZE INFLUENCES TO SET UP THROUGH
THE OVERNIGHT...CAUSING WINDS TO VEER AROUND TO THE SW AND WEST
WITH TIME. ON AVERAGE WINDS WILL BE NO HIGHER THAN 10 KT. SEAS
WILL BE LIMITED...ONLY AROUND 2 FT. WE/LL NEED TO MONITOR FOR
OVERNIGHT CONVECTION FLARING UP ACROSS THE COASTAL WATERS WHERE
THE BEST CONVERGENCE/INSTABILITY WILL OCCUR.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOESN/T APPEAR TO BE MUCH MORE THAN ABOUT 2
FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO WILL KEEP
THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER SWELLS AROUND 3
FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS MAY LEAD TO AN
ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR COLLETON COUNTY AND THE
CHARLESTON TRI-COUNTY REGION THIS EVENING. OUTFLOW BOUNDARIES
PUSHING INLAND SUGGEST THAT THE POTENTIAL FOR ADDITIONAL HEAVY
RAIN WILL GRADUALLY WANE THIS EVENING.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ043>045-
     049-050-052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 152322
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
722 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
THROUGH TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE
NORTHWEST TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A
STRONG INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF
THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WE/VE SEEN PLENTY OF WATER IN THE CHARLESTON TRI-COUNTY AREA THAT
OCCURRED UNFORTUNATELY AROUND THE TIME OF RUSH HOUR...BUT
FORTUNATELY DURING AN OUTGOING TIDE. MUCH OF THIS ACTIVITY APPEARS
TO BE IN A DIMINISHING MODE...BUT UNTIL IT DOES SO WE WILL HOLD
ONTO THE FLASH FLOOD WATCH FOR THE CHARLESTON TRI-COUNTY REGION.

FURTHER TO THE SOUTH THERE IS A CONSOLIDATING AREA OF INTENSE
RAINS SOUTH OF THE ALTAMAHA RIVER THAT HAS DEVELOPED IN
CONJUNCTION WITH THE SEA BREEZE DRIVING NE FROM THE GULF AND
VARIOUS MESO-SCALE BOUNDARIES. ODDS FAVOR THAT THIS CONVECTION
WILL GENERALLY STRUGGLE TO MAKE IT INTO THE CWFA...BUT WE COULD
STILL SEE SOME LOCALLY HEAVY RAINS DOWN NEAR THE ALTAMAHA THROUGH
THIS EVENING. EVEN SO AFTER A METEOROLOGICAL CONSULTATION WE HAVE
OPTED TO CANCEL THE FLASH FLOOD WATCH FOR THESE COUNTIES AND ALL
OTHER COUNTIES OUTSIDE THE CHARLESTON QUAD-COUNTY REGION.

THE DIURNAL TEMP CURVE HAS BEEN CORRUPTED BY THE CONVECTION...BUT
WILL STABILIZE LATER THIS EVENING...THEN HEADING DOWN TO LATE NIGHT
LOWS IN THE 70 TO 75 DEGREE RANGE...LOWEST INLAND AND WARMEST ON
THE ISLAND COMMUNITIES.

WHILE NOT OVERLY CONFIDENT ON SUCH AN OCCURRENCES...MODEL
SOUNDINGS SUGGEST SOME BUILDING DOWN OF STRATUS AND GIVEN THE
RAINFALL TODAY AND YESTERDAY THE GROUNDS IN MANY AREAS ARE QUITE
SATURATED. THIS SHOULD LEAD TO AT LEAST PATCHY FOG LATE TONIGHT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
EXCEPT FOR CIG/VISIBILITY RESTRICTIONS IN SHRA AT KCHS EARLY THIS
EVENING...MAINLY VFR UNTIL AFTER 06Z. THEN...LOW LEVEL MOISTURE
WILL SUPPORT AT LEAST MVFR/IFR CONDITIONS LATE TONIGHT INTO
TUESDAY MORNING...AND LIFR CONDITIONS ARE POSSIBLE. AS
USUAL...THE TIMING AND DEGREE OF DETERIORATION REMAIN UNCERTAIN...
AND AMENDMENTS/ADJUSTMENTS COULD BE REQUIRED WITHIN SUBSEQUENT
FORECASTS TONIGHT. THEN...THUNDERSTORMS ARE AGAIN EXPECTED IN THE
VICINITY OF THE TERMINALS TUESDAY AFTERNOON...AND DIRECT IMPACTS
ARE LIKELY AT KSAV.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TONIGHT...WINDS ARE BEING DRIVEN MAINLY BY LINGERING SEA BREEZE
CIRCULATIONS THIS EVENING. A WEAK SYNOPTIC SCENARIO FOR THE REST OF
THE NIGHT WILL ALLOW FOR LAND BREEZE INFLUENCES TO SET UP THROUGH
THE OVERNIGHT...CAUSING WINDS TO VEER AROUND TO THE SW AND WEST
WITH TIME. ON AVERAGE WINDS WILL BE NO HIGHER THAN 10 KT. SEAS
WILL BE LIMITED...ONLY AROUND 2 FT. WE/LL NEED TO MONITOR FOR
OVERNIGHT CONVECTION FLARING UP ACROSS THE COASTAL WATERS WHERE
THE BEST CONVERGENCE/INSTABILITY WILL OCCUR.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOESN/T APPEAR TO BE MUCH MORE THAN ABOUT 2
FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO WILL KEEP
THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER SWELLS AROUND 3
FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS MAY LEAD TO AN
ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR COLLETON COUNTY AND THE
CHARLESTON TRI-COUNTY REGION THIS EVENING. OUTFLOW BOUNDARIES
PUSHING INLAND SUGGEST THAT THE POTENTIAL FOR ADDITIONAL HEAVY
RAIN WILL GRADUALLY WANE THIS EVENING.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ043>045-
     049-050-052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 152232
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
632 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
THROUGH TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE
NORTHWEST TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A
STRONG INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF
THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WE/VE SEEN PLENTY OF WATER IN THE CHARLESTON TRI-COUNTY AREA THAT
OCCURRED UNFORTUNATELY AROUND THE TIME OF RUSH HOUR...BUT
FORTUNATELY DURING AN OUTGOING TIDE. MUCH OF THIS ACTIVITY APPEARS
TO BE IN A DIMINISHING MODE...BUT UNTIL IT DOES SO WE WILL HOLD
ONTO THE FLASH FLOOD WATCH FOR THE CHARLESTON TRI-COUNTY REGION.

FURTHER TO THE SOUTH THERE IS A CONSOLIDATING AREA OF INTENSE
RAINS SOUTH OF THE ALTAMAHA RIVER THAT HAS DEVELOPED IN
CONJUNCTION WITH THE SEA BREEZE DRIVING NE FROM THE GULF AND
VARIOUS MESO-SCALE BOUNDARIES. ODDS FAVOR THAT THIS CONVECTION
WILL GENERALLY STRUGGLE TO MAKE IT INTO THE CWFA...BUT WE COULD
STILL SEE SOME LOCALLY HEAVY RAINS DOWN NEAR THE ALTAMAHA THROUGH
THIS EVENING. EVEN SO AFTER A METEOROLOGICAL CONSULTATION WE HAVE
OPTED TO CANCEL THE FLASH FLOOD WATCH FOR THESE COUNTIES AND ALL
OTHER COUNTIES OUTSIDE THE CHARLESTON QUAD-COUNTY REGION.

THE DIURNAL TEMP CURVE HAS BEEN CORRUPTED BY THE CONVECTION...BUT
WILL STABILIZE LATER THIS EVENING...THEN HEADING DOWN TO LATE NIGHT
LOWS IN THE 70 TO 75 DEGREE RANGE...LOWEST INLAND AND WARMEST ON
THE ISLAND COMMUNITIES.

WHILE NOT OVERLY CONFIDENT ON SUCH AN OCCURRENCES...MODEL
SOUNDINGS SUGGEST SOME BUILDING DOWN OF STRATUS AND GIVEN THE
RAINFALL TODAY AND YESTERDAY THE GROUNDS IN MANY AREAS ARE QUITE
SATURATED. THIS SHOULD LEAD TO AT LEAST PATCHY FOG LATE TONIGHT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
GENERALLY VFR CONDS EXPECTED OUTSIDE SHOWERS AND TSTMS THROUGH
THIS EVENING...ALTHOUGH SOME SHOWERS COULD LINGER OVERNIGHT INTO
TUESDAY WITH THE STALLED FRONT NEARBY AND PLENTY OF MOISTURE TO GO
AROUND. LOW CIGS EXPECTED AGAIN TONIGHT AS LOW-LEVEL MOISTURE GETS
TRAPPED UNDERNEATH THE INVERSION...POSSIBLY GOING LIFR AND PROBABLY
LOWERING ENOUGH TO EVEN YIELD SOME MVFR VSBYS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TONIGHT...WINDS ARE BEING DRIVEN MAINLY BY LINGERING SEA BREEZE
CIRCULATIONS THIS EVENING. A WEAK SYNOPTIC SCENARIO FOR THE REST OF
THE NIGHT WILL ALLOW FOR LAND BREEZE INFLUENCES TO SET UP THROUGH
THE OVERNIGHT...CAUSING WINDS TO VEER AROUND TO THE SW AND WEST
WITH TIME. ON AVERAGE WINDS WILL BE NO HIGHER THAN 10 KT. SEAS
WILL BE LIMITED...ONLY AROUND 2 FT. WE/LL NEED TO MONITOR FOR
OVERNIGHT CONVECTION FLARING UP ACROSS THE COASTAL WATERS WHERE
THE BEST CONVERGENCE/INSTABILITY WILL OCCUR.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOESN/T APPEAR TO BE MUCH MORE THAN ABOUT 2
FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO WILL KEEP
THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER SWELLS AROUND 3
FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS MAY LEAD TO AN
ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ043>045-
     049-050-052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 152232
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
632 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
THROUGH TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE
NORTHWEST TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A
STRONG INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF
THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WE/VE SEEN PLENTY OF WATER IN THE CHARLESTON TRI-COUNTY AREA THAT
OCCURRED UNFORTUNATELY AROUND THE TIME OF RUSH HOUR...BUT
FORTUNATELY DURING AN OUTGOING TIDE. MUCH OF THIS ACTIVITY APPEARS
TO BE IN A DIMINISHING MODE...BUT UNTIL IT DOES SO WE WILL HOLD
ONTO THE FLASH FLOOD WATCH FOR THE CHARLESTON TRI-COUNTY REGION.

FURTHER TO THE SOUTH THERE IS A CONSOLIDATING AREA OF INTENSE
RAINS SOUTH OF THE ALTAMAHA RIVER THAT HAS DEVELOPED IN
CONJUNCTION WITH THE SEA BREEZE DRIVING NE FROM THE GULF AND
VARIOUS MESO-SCALE BOUNDARIES. ODDS FAVOR THAT THIS CONVECTION
WILL GENERALLY STRUGGLE TO MAKE IT INTO THE CWFA...BUT WE COULD
STILL SEE SOME LOCALLY HEAVY RAINS DOWN NEAR THE ALTAMAHA THROUGH
THIS EVENING. EVEN SO AFTER A METEOROLOGICAL CONSULTATION WE HAVE
OPTED TO CANCEL THE FLASH FLOOD WATCH FOR THESE COUNTIES AND ALL
OTHER COUNTIES OUTSIDE THE CHARLESTON QUAD-COUNTY REGION.

THE DIURNAL TEMP CURVE HAS BEEN CORRUPTED BY THE CONVECTION...BUT
WILL STABILIZE LATER THIS EVENING...THEN HEADING DOWN TO LATE NIGHT
LOWS IN THE 70 TO 75 DEGREE RANGE...LOWEST INLAND AND WARMEST ON
THE ISLAND COMMUNITIES.

WHILE NOT OVERLY CONFIDENT ON SUCH AN OCCURRENCES...MODEL
SOUNDINGS SUGGEST SOME BUILDING DOWN OF STRATUS AND GIVEN THE
RAINFALL TODAY AND YESTERDAY THE GROUNDS IN MANY AREAS ARE QUITE
SATURATED. THIS SHOULD LEAD TO AT LEAST PATCHY FOG LATE TONIGHT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
GENERALLY VFR CONDS EXPECTED OUTSIDE SHOWERS AND TSTMS THROUGH
THIS EVENING...ALTHOUGH SOME SHOWERS COULD LINGER OVERNIGHT INTO
TUESDAY WITH THE STALLED FRONT NEARBY AND PLENTY OF MOISTURE TO GO
AROUND. LOW CIGS EXPECTED AGAIN TONIGHT AS LOW-LEVEL MOISTURE GETS
TRAPPED UNDERNEATH THE INVERSION...POSSIBLY GOING LIFR AND PROBABLY
LOWERING ENOUGH TO EVEN YIELD SOME MVFR VSBYS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TONIGHT...WINDS ARE BEING DRIVEN MAINLY BY LINGERING SEA BREEZE
CIRCULATIONS THIS EVENING. A WEAK SYNOPTIC SCENARIO FOR THE REST OF
THE NIGHT WILL ALLOW FOR LAND BREEZE INFLUENCES TO SET UP THROUGH
THE OVERNIGHT...CAUSING WINDS TO VEER AROUND TO THE SW AND WEST
WITH TIME. ON AVERAGE WINDS WILL BE NO HIGHER THAN 10 KT. SEAS
WILL BE LIMITED...ONLY AROUND 2 FT. WE/LL NEED TO MONITOR FOR
OVERNIGHT CONVECTION FLARING UP ACROSS THE COASTAL WATERS WHERE
THE BEST CONVERGENCE/INSTABILITY WILL OCCUR.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOESN/T APPEAR TO BE MUCH MORE THAN ABOUT 2
FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO WILL KEEP
THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER SWELLS AROUND 3
FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS MAY LEAD TO AN
ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ043>045-
     049-050-052.
MARINE...NONE.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 152007
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
407 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
THROUGH TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE
NORTHWEST TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A
STRONG INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF
THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SURFACE OBS INDICATE THE STALLED WEDGE FRONT HAS PRETTY MUCH
RETREATED TO THE NORTHWEST OF THE AREA AS HEATING CONTINUES TO
ERODE THE WEDGE FROM THE SOUTH AND EAST. NUMEROUS SHOWERS AND
SOME THUNDERSTORMS WILL CONTINUE TO PRODUCE A HEAVY RAIN THREAT
THROUGH THIS EVENING AS THE SEA BREEZE SLOWLY WORKS INLAND BEFORE
WINDING DOWN OVERNIGHT.. HOWEVER...SOME SHOWERS COULD OCCUR
THROUGH THE NIGHT AS WEAK SHORTWAVE ENERGY MOVES BY TO THE NORTH
AND DEEP MOISTURE REMAINS OVER THE AREA ALONG WITH THE NEARBY FRONT.
MOISTURE TRAPPED UNDER THE INVERSION WILL LEAD TO STRATUS...WHICH
COULD LEAD TO A BIT OF FOG AS WELL...MAINLY IN AREAS THAT SEE RAIN
TODAY. LOWS MAINLY IN THE LOWER TO MID 70S...BUT WILL BE LARGELY
DETERMINED BY THE RAIN.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
GENERALLY VFR CONDS EXPECTED OUTSIDE SHOWERS AND TSTMS THROUGH
THIS EVENING...ALTHOUGH SOME SHOWERS COULD LINGER OVERNIGHT INTO
TUESDAY WITH THE STALLED FRONT NEARBY AND PLENTY OF MOISTURE TO GO
AROUND. LOW CIGS EXPECTED AGAIN TONIGHT AS LOW-LEVEL MOISTURE GETS
TRAPPED UNDERNEATH THE INVERSION...POSSIBLY GOING LIFR AND PROBABLY
LOWERING ENOUGH TO EVEN YIELD SOME MVFR VSBYS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TONIGHT...DISSIPATING FRONT WILL MEAN WINDS BECOMING MORE
SOUTHERLY THIS EVENING AND THEN VEERING TO THE SOUTHWEST TO WEST
LATE. WINDS WILL REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT
2-3 FT OVER THE GEORGIA OFFSHORE LEG.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOESN/T APPEAR TO BE MUCH MORE THAN ABOUT 2
FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO WILL KEEP
THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER SWELLS AROUND 3
FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS MAY LEAD TO AN
ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH WILL REMAIN IN EFFECT FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING.
HIGH PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED
WITH FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS
INDICATE THERE WILL BE SOME SLOW-MOVING SHOWERS/TSTMS INTO THIS
EVENING. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN PRODUCERS
WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES IN EXCESS
OF 2-3 IN/HR...WHICH ARE NEAR THE FLASH FLOOD GUIDANCE VALUES. THE
BEST CHANCE OF FLOODING APPEARS TO BE ACROSS SOUTHEAST GEORGIA
NORTHEASTWARD INTO COASTAL SECTIONS OF SOUTH CAROLINA.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR GAZ087-088-
     099>101-114>119-137>141.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ040-
     042>045-047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...33
LONG TERM...
AVIATION...33/RJB
MARINE...33/RJB
HYDROLOGY...







000
FXUS62 KCHS 152007
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
407 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL CONTINUE TO DISSIPATE OVER THE AREA
THROUGH TONIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE
NORTHWEST TUESDAY AND PUSH THROUGH THE REGION LATE WEDNESDAY. A
STRONG INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF
THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SURFACE OBS INDICATE THE STALLED WEDGE FRONT HAS PRETTY MUCH
RETREATED TO THE NORTHWEST OF THE AREA AS HEATING CONTINUES TO
ERODE THE WEDGE FROM THE SOUTH AND EAST. NUMEROUS SHOWERS AND
SOME THUNDERSTORMS WILL CONTINUE TO PRODUCE A HEAVY RAIN THREAT
THROUGH THIS EVENING AS THE SEA BREEZE SLOWLY WORKS INLAND BEFORE
WINDING DOWN OVERNIGHT.. HOWEVER...SOME SHOWERS COULD OCCUR
THROUGH THE NIGHT AS WEAK SHORTWAVE ENERGY MOVES BY TO THE NORTH
AND DEEP MOISTURE REMAINS OVER THE AREA ALONG WITH THE NEARBY FRONT.
MOISTURE TRAPPED UNDER THE INVERSION WILL LEAD TO STRATUS...WHICH
COULD LEAD TO A BIT OF FOG AS WELL...MAINLY IN AREAS THAT SEE RAIN
TODAY. LOWS MAINLY IN THE LOWER TO MID 70S...BUT WILL BE LARGELY
DETERMINED BY THE RAIN.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...THE PATTERN ALOFT WILL FEATURE A BROAD TROUGH OVER THE
EASTERN STATES. A STRONG BUT DAMPENING SHORT WAVE WILL LIFT THROUGH
NEW ENGLAND...WHILE A SECOND AND ALSO WEAKENING SHORT WAVE HEADS
INTO OUR AREA WITHIN THE WEST-NW FLOW. THIS FEATURE LOOKED TO BE
FOUND IN THE MID-MS VALLEY AS OF LATE MONDAY. AT THE SURFACE THE
PRESSURE PATTERN BECOMES RATHER NEBULOUS AS A PRE-FRONTAL TROUGH
ALIGNED MAINLY NE-SW SETS UP ACROSS THE REGION AHEAD OF OUR MID WEEK
COLD FRONT. THERE IS A SLIGHT DECREASE IN MOISTURE PROFILES...WITH
PWATS TO FALL TO AROUND 2 INCHES. ALTHOUGH NOT AS MUCH AS RECENT
DAYS...IT IS STILL ABOVE THE 75TH PERCENTILE FOR MID-SEPTEMBER.
THERE IS LARGE SCALE FORCING ASSOCIATED WITH THE RIGHT ENTRANCE
REGION TO THE UPPER JET AND VARIOUS BOUNDARY INTERACTIONS THAT
DEVELOP FOR THE AFTERNOON HOURS. WE HAVE SCATTERED TO LIKELY POPS
ACROSS THE ENTIRE REGION...WITH THE GREATEST COVERAGE FROM NEAR THE
SAVANNAH AREA TO MCINTOSH AND LONG COUNTIES WHERE THE SEA BREEZE
WILL BE MOST ACTIVE. THERE IS A LITTLE BETTER STORM MOTION THAN
PREVIOUS DAYS...BUT NOT ENOUGH TO PREVENT AT LEAST LOCALLY HEAVY
RAINS FROM DEVELOPING. COVERAGE IS NOT ENOUGH FOR A FLASH FLOOD
WATCH BUT WILL MENTION POTENTIAL FLOODING RAINS IN THE HAZARDOUS
WEATHER OUTLOOK. WITH A LITTLE DRIER AIR ALOFT...SLIGHTLY COOLER MID
LEVEL AIR AND BETTER VERTICAL WIND FIELDS THAN OF LATE...THERE IS A
VERY LOW RISK OF SOME GUSTY WINDS WHERE THE BOUNDARY
MERGERS/INTERACTIONS/COLLISIONS OCCUR. ALTHOUGH THE DAY WILL START
WITH LOW STRATUS AND PATCHY FOG...WHICH WILL LIFT INTO A FAIRLY
EXTENSIVE CUMULUS FIELD...DOWNSLOPE TRAJECTORIES THROUGHOUT MUCH OF
THE TROPOSPHERE WILL BOOST TEMPS INTO THE UPPER 80S PRIOR TO THE
ONSET OF THE CONVECTIVE RAINS.

WEDNESDAY THROUGH THURSDAY...OUR NEXT COLD FRONT WILL LIMP TOWARD
THE AREA WEDNESDAY AS IT BECOMES ORIENTED SOMEWHAT PARALLEL TO THE
FLOW ALOFT...AND WAITS FOR THE PUSH FROM CANADIAN HIGH PRESSURE LATE
WEDNESDAY INTO THURSDAY TO KICK THE FRONT THROUGH. MID LEVEL
IMPULSES WILL FORM AT LEAST ONE WAVE OF LOW PRESSURE ALONG THE
FRONT...WHICH ALSO ACTS TO SLOW IT DOWN SOME ON WEDNESDAY. BUT AS
THE MID/UPPER PATTERN AMPLIFIES FURTHER WEDNESDAY NIGHT AND
THURSDAY...THE WAVE AND FRONT WILL PUSH OFFSHORE. IT IS WORTH NOTING
THAT THERE IS NO SIGNS OF ANY TROPICAL CHARACTERISTICS WITH THIS
FEATURE AT THIS TIME. WE NEED TO HOLD ONTO SLIGHT CHANCE AND CHANCE
POPS IN ADVANCE OF THE COLD FRONT WEDNESDAY...WITH PROBABLY NO MORE
THAN SLIGHT CHANCE POPS FOR THURSDAY IN RESPONSE TO WEAK LOW LEVEL
CONVERGENCE OFF THE ATLANTIC. THE COOL AIR LAGS FAR BEHIND THE FRONT
WEDNESDAY...WHICH WILL ALLOW FOR TEMPS TO STILL PEAK IN THE UPPER 80S
TO AROUND 90. COOLER AIR THEN MOVES IN WITH THE BEST COOL ADVECTION
WEDNESDAY NIGHT...WITH LOWS DOWN INTO THE MID AND UPPER 60S AWAY
FROM THE BARRIER ISLANDS. THURSDAY WILL BE A REFRESHING CHANGE IN
AIR MASS WITH LOWER DEW POINTS AND HIGHS ACTUALLY DOWN BELOW
CLIMATOLOGICAL NORMS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
GENERALLY VFR CONDS EXPECTED OUTSIDE SHOWERS AND TSTMS THROUGH
THIS EVENING...ALTHOUGH SOME SHOWERS COULD LINGER OVERNIGHT INTO
TUESDAY WITH THE STALLED FRONT NEARBY AND PLENTY OF MOISTURE TO GO
AROUND. LOW CIGS EXPECTED AGAIN TONIGHT AS LOW-LEVEL MOISTURE GETS
TRAPPED UNDERNEATH THE INVERSION...POSSIBLY GOING LIFR AND PROBABLY
LOWERING ENOUGH TO EVEN YIELD SOME MVFR VSBYS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TONIGHT...DISSIPATING FRONT WILL MEAN WINDS BECOMING MORE
SOUTHERLY THIS EVENING AND THEN VEERING TO THE SOUTHWEST TO WEST
LATE. WINDS WILL REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT
2-3 FT OVER THE GEORGIA OFFSHORE LEG.

TUESDAY...WEAK OFFSHORE FLOW IN THE MORNING WILL SHIFT AROUND TO
ONSHORE WITH THE SEA BREEZE INFLUENCES FOR THE AFTERNOON. SMALL BUT
LONG PERIOD SWELLS AROUND 15-16 SECONDS FROM HURRICANE EDOUARD MAY
ARRIVE BY LATE IN THE DAY...BUT WITH SIGNIFICANT WAVE HEIGHT NO MORE
THAN 2 OR 3 FT. CONDITIONS AGAIN FAVOR WATERSPOUTS DURING THE
MORNING HOURS...ONCE ANY LOW STRATUS AND/OR FOG IN CHARLESTON HARBOR
AND THE NEARBY ATLANTIC WATERS LIFTS/DISSIPATES.

WEDNESDAY THROUGH THURSDAY...A COLD FRONT AND WAVE OF LOW PRESSURE
WILL PROGRESS INTO AND THROUGH THE WATERS DURING THE MID WEEK
PERIOD. LIGHT TO GENTLE BREEZES IN ADVANCE OF THE FRONT WILL GIVE
WAY TO MODERATE BREEZES AFTER BEHIND THE FRONT. SEAS WILL BE
COMPRISED MAINLY OF LONG PERIOD SWELLS FROM DISTANT
EDOUARD...AVERAGING AROUND 2-4 FT WITHIN 20 NM AND 3-5 FT FURTHER
OUT.

FRIDAY THROUGH SUNDAY...THE PRESSURE GRADIENT WILL BECOME QUITE
PINCHED AS THE COLD FRONT STALLS AND BECOMES STATIONARY TO OUR SE
AND A STRONG INLAND WEDGE OF HIGH PRESSURE DEVELOPS. A LONG ONSHORE
FETCH AND STRONGER NE WINDS LOOK TO SUPPORT THE ISSUANCE OF SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD COULD
START ARRIVING AT THE BEACHES LATE TUESDAY AND CONTINUE INTO
THURSDAY. FOR NOW THERE DOESN/T APPEAR TO BE MUCH MORE THAN ABOUT 2
FT SWELL THAT MAKES IT TO THE BEACHES BY LATE TUESDAY...SO WILL KEEP
THE RIP CURRENT RISK LOW. HOWEVER...SLIGHTLY LARGER SWELLS AROUND 3
FT MIGHT OCCUR WEDNESDAY INTO THURSDAY...AND THIS MAY LEAD TO AN
ENHANCED RISK OF RIP CURRENTS.

FOR FRIDAY THROUGH SUNDAY WE LOSE THE SWELL FROM EDOUARD...BUT
STRONGER NE WINDS WILL OCCUR AND THIS MAY ALLOW FOR AN ELEVATED RISK
OF RIP CURRENTS TO AGAIN PREVAIL AT AREA BEACHES.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH WILL REMAIN IN EFFECT FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING.
HIGH PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED
WITH FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS
INDICATE THERE WILL BE SOME SLOW-MOVING SHOWERS/TSTMS INTO THIS
EVENING. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN PRODUCERS
WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES IN EXCESS
OF 2-3 IN/HR...WHICH ARE NEAR THE FLASH FLOOD GUIDANCE VALUES. THE
BEST CHANCE OF FLOODING APPEARS TO BE ACROSS SOUTHEAST GEORGIA
NORTHEASTWARD INTO COASTAL SECTIONS OF SOUTH CAROLINA.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR GAZ087-088-
     099>101-114>119-137>141.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ040-
     042>045-047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...33
LONG TERM...
AVIATION...33/RJB
MARINE...33/RJB
HYDROLOGY...








000
FXUS62 KCHS 151727
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
127 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO SIGNIFICANT CHANGES TO PREVIOUS FORECAST. RADAR INDICATES MOST
OF THE SHOWERS AND A FEW THUNDERSTORMS DEVELOPING JUST SOUTH OF
SAVANNAH WHERE INSTABILITY IS BEST AND THE SEA BREEZE IS STARTING
TO DEVELOP. LATEST SHORT-TERM MODEL GUIDANCE INDICATES THIS
CONVECTION WILL CONTINUE TO FIRE NORTHWARD ALONG THE SEA BREEZE UP
INTO SOUTHERN SC.

IT IS ANOTHER TRICKY FORECAST TODAY...ESPECIALLY REGARDING THE
POTENTIAL FOR HEAVY RAINFALL/FLOODING. THE SYNOPTIC PATTERN
CONTINUES TO FAVOR HEAVY RAINFALL WITH A WEAKENING FRONT OVER THE
AREA...PLENTIFUL MOISTURE IN PLACE AS INDICATED BY THE 2.15 IN
PWAT ON THE 12Z CHS SOUNDING AND SOME UPPER JET FORCING. ON THE
MESOSCALE THERE WILL BE A WEAK SEA BREEZE AND SOME DIFFERENTIAL
HEATING BOUNDARIES. LOOKS LIKE THE BEST RAIN CHANCES WILL COME
LATER THIS AFTERNOON AS THE FLOW BECOMES MORE ONSHORE WITH THE SEA
BREEZE. SEE THE HYDROLOGY SECTION BELOW ON INFORMATION ADDRESSING
THE POTENTIAL FOR FLASH FLOODING. HIGHS SHOULD RANGE FROM THE MID
80S MOST PLACES WITH SOME UPPER 80S CLOSER TO THE ALTAMAHA WHERE
MORE SUN IS EXPECTED SOUTH OF THE DECAYING FRONT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.

TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.

DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.

WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /18Z MONDAY THROUGH FRIDAY/...
GENERALLY VFR CONDS EXPECTED OUTSIDE SHOWERS AND TSTMS THROUGH
THIS EVENING...ALTHOUGH SOME SHOWERS COULD LINGER OVERNIGHT INTO
TUESDAY WITH THE STALLED FRONT NEARBY AND PLENTY OF MOISTURE TO GO
AROUND. LOW CIGS EXPECTED AGAIN TONIGHT AS LOW-LEVEL MOISTURE GETS
TRAPPED UNDERNEATH THE INVERSION...POSSIBLY GOING LIFR AND PROBABLY
LOWERING ENOUGH TO EVEN YIELD SOME MVFR VSBYS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.

TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE SOME SLOW-MOVING SHOWERS/TSTMS LATER TODAY INTO THIS
EVENING. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN PRODUCERS
WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES IN EXCESS
OF 2-3 IN/HR...WHICH IS NEAR THE FLASH FLOOD GUIDANCE VALUES. THE
BEST CHANCE OF FLOODING IS LIKELY IN AREAS THAT HAVE SEEN RECENT
HEAVY RAINFALL.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR GAZ087-088-
     099>101-114>119-137>141.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ040-
     042>045-047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...RJB
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 151727
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
127 PM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO SIGNIFICANT CHANGES TO PREVIOUS FORECAST. RADAR INDICATES MOST
OF THE SHOWERS AND A FEW THUNDERSTORMS DEVELOPING JUST SOUTH OF
SAVANNAH WHERE INSTABILITY IS BEST AND THE SEA BREEZE IS STARTING
TO DEVELOP. LATEST SHORT-TERM MODEL GUIDANCE INDICATES THIS
CONVECTION WILL CONTINUE TO FIRE NORTHWARD ALONG THE SEA BREEZE UP
INTO SOUTHERN SC.

IT IS ANOTHER TRICKY FORECAST TODAY...ESPECIALLY REGARDING THE
POTENTIAL FOR HEAVY RAINFALL/FLOODING. THE SYNOPTIC PATTERN
CONTINUES TO FAVOR HEAVY RAINFALL WITH A WEAKENING FRONT OVER THE
AREA...PLENTIFUL MOISTURE IN PLACE AS INDICATED BY THE 2.15 IN
PWAT ON THE 12Z CHS SOUNDING AND SOME UPPER JET FORCING. ON THE
MESOSCALE THERE WILL BE A WEAK SEA BREEZE AND SOME DIFFERENTIAL
HEATING BOUNDARIES. LOOKS LIKE THE BEST RAIN CHANCES WILL COME
LATER THIS AFTERNOON AS THE FLOW BECOMES MORE ONSHORE WITH THE SEA
BREEZE. SEE THE HYDROLOGY SECTION BELOW ON INFORMATION ADDRESSING
THE POTENTIAL FOR FLASH FLOODING. HIGHS SHOULD RANGE FROM THE MID
80S MOST PLACES WITH SOME UPPER 80S CLOSER TO THE ALTAMAHA WHERE
MORE SUN IS EXPECTED SOUTH OF THE DECAYING FRONT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.

TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.

DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.

WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /18Z MONDAY THROUGH FRIDAY/...
GENERALLY VFR CONDS EXPECTED OUTSIDE SHOWERS AND TSTMS THROUGH
THIS EVENING...ALTHOUGH SOME SHOWERS COULD LINGER OVERNIGHT INTO
TUESDAY WITH THE STALLED FRONT NEARBY AND PLENTY OF MOISTURE TO GO
AROUND. LOW CIGS EXPECTED AGAIN TONIGHT AS LOW-LEVEL MOISTURE GETS
TRAPPED UNDERNEATH THE INVERSION...POSSIBLY GOING LIFR AND PROBABLY
LOWERING ENOUGH TO EVEN YIELD SOME MVFR VSBYS.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.

TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE SOME SLOW-MOVING SHOWERS/TSTMS LATER TODAY INTO THIS
EVENING. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN PRODUCERS
WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES IN EXCESS
OF 2-3 IN/HR...WHICH IS NEAR THE FLASH FLOOD GUIDANCE VALUES. THE
BEST CHANCE OF FLOODING IS LIKELY IN AREAS THAT HAVE SEEN RECENT
HEAVY RAINFALL.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR GAZ087-088-
     099>101-114>119-137>141.
SC...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR SCZ040-
     042>045-047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...RJB
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 151516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1116 AM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEDGE PATTERN IN PLACE WITH A STATIONARY FRONT BISECTING THE
FORECAST AREA. RADAR INDICATES MOST OF THE SHOWERS NORTH OF THE
AREA FROM AROUND AUGUSTA TO MYRTLE BEACH WHERE THE BEST DEEP
MOISTURE CONVERGENCE IS FOUND. IT IS ANOTHER TRICKY FORECAST
TODAY...ESPECIALLY REGARDING THE POTENTIAL FOR HEAVY
RAINFALL/FLOODING. THE SYNOPTIC PATTERN CONTINUES TO FAVOR HEAVY
RAINFALL WITH A WEAKENING FRONT OVER THE AREA...PLENTIFUL
MOISTURE IN PLACE AS INDICATED BY THE 2.15 IN PWAT ON THE 12Z CHS
SOUNDING AND SOME UPPER JET FORCING. ON THE MESOSCALE THERE WILL
BE A WEAK SEA BREEZE AND SOME DIFFERENTIAL HEATING BOUNDARIES.
LOOKS LIKE THE BEST RAIN CHANCES WILL COME LATER THIS AFTERNOON AS
THE FLOW BECOMES MORE ONSHORE WITH THE SEA BREEZE. SEE THE
HYDROLOGY SECTION BELOW ON INFORMATION ADDRESSING THE POTENTIAL
FOR FLASH FLOODING. HIGHS SHOULD RANGE FROM THE MID 80S MOST
PLACES WITH SOME UPPER 80S CLOSER TO THE ALTAMAHA WHERE MORE SUN
IS EXPECTED SOUTH OF THE DECAYING FRONT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.

TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.

DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.

WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
MVFR/IFR CIGS SHOULD LIFT TO VFR SOON WITH VFR CONDS THEN EXPECTED
OUTSIDE SHOWERS AND TSTMS THIS AFTERNOON/EVENING. LOW CIGS ARE POSSIBLE
AGAIN TONIGHT AND SUB- VFR CONDITIONS MAY NEED TO BE INTRODUCED IN
LATER FORECAST CYCLES.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.

TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE SOME SLOW-MOVING SHOWERS/TSTMS LATER TODAY INTO THIS
EVENING. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN PRODUCERS
WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES IN EXCESS
OF 2-3 IN/HR...WHICH IS NEAR THE FLASH FLOOD GUIDANCE VALUES. THE
BEST CHANCE OF FLOODING IS LIKELY IN AREAS THAT HAVE SEEN RECENT
HEAVY RAINFALL.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
     114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
     047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 151516
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1116 AM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEDGE PATTERN IN PLACE WITH A STATIONARY FRONT BISECTING THE
FORECAST AREA. RADAR INDICATES MOST OF THE SHOWERS NORTH OF THE
AREA FROM AROUND AUGUSTA TO MYRTLE BEACH WHERE THE BEST DEEP
MOISTURE CONVERGENCE IS FOUND. IT IS ANOTHER TRICKY FORECAST
TODAY...ESPECIALLY REGARDING THE POTENTIAL FOR HEAVY
RAINFALL/FLOODING. THE SYNOPTIC PATTERN CONTINUES TO FAVOR HEAVY
RAINFALL WITH A WEAKENING FRONT OVER THE AREA...PLENTIFUL
MOISTURE IN PLACE AS INDICATED BY THE 2.15 IN PWAT ON THE 12Z CHS
SOUNDING AND SOME UPPER JET FORCING. ON THE MESOSCALE THERE WILL
BE A WEAK SEA BREEZE AND SOME DIFFERENTIAL HEATING BOUNDARIES.
LOOKS LIKE THE BEST RAIN CHANCES WILL COME LATER THIS AFTERNOON AS
THE FLOW BECOMES MORE ONSHORE WITH THE SEA BREEZE. SEE THE
HYDROLOGY SECTION BELOW ON INFORMATION ADDRESSING THE POTENTIAL
FOR FLASH FLOODING. HIGHS SHOULD RANGE FROM THE MID 80S MOST
PLACES WITH SOME UPPER 80S CLOSER TO THE ALTAMAHA WHERE MORE SUN
IS EXPECTED SOUTH OF THE DECAYING FRONT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.

TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.

DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.

WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
MVFR/IFR CIGS SHOULD LIFT TO VFR SOON WITH VFR CONDS THEN EXPECTED
OUTSIDE SHOWERS AND TSTMS THIS AFTERNOON/EVENING. LOW CIGS ARE POSSIBLE
AGAIN TONIGHT AND SUB- VFR CONDITIONS MAY NEED TO BE INTRODUCED IN
LATER FORECAST CYCLES.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.

TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE SOME SLOW-MOVING SHOWERS/TSTMS LATER TODAY INTO THIS
EVENING. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN PRODUCERS
WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES IN EXCESS
OF 2-3 IN/HR...WHICH IS NEAR THE FLASH FLOOD GUIDANCE VALUES. THE
BEST CHANCE OF FLOODING IS LIKELY IN AREAS THAT HAVE SEEN RECENT
HEAVY RAINFALL.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
     114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
     047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







000
FXUS62 KCHS 151119
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
719 AM EDT MON SEP 15 2014

...LOCALLY HEAVY RAINFALL AND FLASH FLOODING POSSIBLE THIS
AFTERNOON AND EVENING...

.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 15/10Z...THE STATIONARY FRONT WAS ROUGHLY POSITIONED ALONG A
MILLEN-NEWINGTON-RIDGEVILLE-SEABROOK ISLAND LINE PER LATEST
RAP INSTABILITY PLOTS AND SURFACE OBSERVATION. FOR THE EARLY
MORNING UPDATE...

1. STRATUS BUILD DOWN HAS RESULTED IN SOME LOW VSBYS NORTH OF THE
STATIONARY FRONT EARLY THIS MORNING. THE FOG HAS BECOME LOCALLY
DENSE WHERE CIGS HAVE DROPPED BELOW 100 FT AT TIMES. A SPECIAL
WEATHER STATEMENT HAS BEEN ISSUED TO HANDLE THIS THROUGH 830 AM.
A DENSE FOG ADVISORY IS NOT ANTICIPATED...BUT CONDITIONS WILL
CONTINUE TO BE CLOSELY MONITORED.

2. HIGH RESOLUTION MODELS CONTINUE TO KEY IN ON THE CORRIDOR
ROUGHLY BOUNDED BY STATESBORO...SAVANNAH...DARIEN AND GLENNVILLE
FOR THE MOST SIGNIFICANT HEAVY RAINS TODAY. POPS HAVE BEEN
INCREASED IN THIS AREA TO CATEGORICAL...80 PERCENT...TO COVER.
THERE REMAINS A RISK FOR FLASH FLOODING JUST ABOUT ANYWHERE TODAY.

TODAY...THE SYNOPTIC PATTERN CONTINUES TO FAVOR A HEAVY RAIN
SETUP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
WEAK STATIONARY FRONT THAT IS CURRENTLY BISECTING THE FORECAST
AREA IS FORECAST TO GRADUALLY WASH OUT THIS AFTERNOON AS BROAD
PRESSURE FALLS AHEAD OF POWERFUL SHORTWAVE ENERGY DIGGING INTO THE
OHIO VALLEY OVERSPREAD THE REGION. THE UPPER JET CONFIGURATION
REMAINS IN A FAVORABLE ORIENTATION FOR UPPER SUPPORT WITH THE
RIGHT ENTRANCE REGION FORECAST OR PROVIDE ANOTHER CORRIDOR OF
ENHANCED UPPER DIVERGENCE ATOP THE DECAYING FRONT AND SEA BREEZE
CIRCULATION DURING PEAK HEATING. MOST OF THE HIGH RESOLUTION
MODELS ARE SHOWING A SIGNAL FOR A CORRIDOR OF TORRENTIAL RAINS TO
SETUP ALONG THE I-95 CORRIDOR BY EARLY-MID AFTERNOON...POSSIBLY
INITIATING ALONG THE GEORGIA COAST...THEN GRADUALLY SPREADING
INLAND AND TO THE NORTH WITH THE SEA BREEZE. RAINFALL AMOUNTS OF
2 INCHES WITH LOCALLY HIGHER AMOUNTS IN EXCESS OF 5 INCHES WILL BE
POSSIBLE WITH SMALL MEAN STORM MOTION VECTORS AND ANOMALOUSLY HIGH
TROPOSPHERIC MOISTURE IN PLACE. SEE THE HYDROLOGY SECTION BELOW ON
INFORMATION ADDRESSING THE POTENTIAL FOR FLASH FLOODING.

POPS WILL BE INCREASED TO 60-70 PERCENT FOR MOST AREAS TODAY...
MAINLY DURING THE AFTERNOON HOURS. MUCH OF THE MORNING MAY
ACTUALLY BE FAIRLY QUIET...BUT AS THE FRONT BEGINS TO WASHES OUT
AND INSTABILITY INCREASES...EXPECT CONVECTIVE INITIATION TO OCCUR
BY EARLY AFTERNOON. SEVERAL GUIDANCE MEMBERS SUGGEST CATEGORICAL
POPS MAY EVENTUALLY BE NEEDED...WHICH WILL NEED TO BE CONSIDERED
LATER TODAY ONCE MESOSCALE CONVECTIVE TRENDS BECOME MORE APPARENT.
HIGHS WILL RANGE FROM THE MID 80S NORTH TO THE UPPER 80S ROUGHLY
SOUTH OF I-16.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.

TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.

DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.

WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
KCHS...LOW-END IFR CIGS WILL LINGER THROUGH ABOUT 15Z WITH
IMPROVING CONDITIONS TO VFR THEREAFTER. HIGH RESOLUTION MODELS
STILL SUGGEST THERE WILL BE AN ELEVATED RISK FOR TSTM IMPACTS AT
THE TERMINAL TODAY...ALTHOUGH THE BULK OF THE ACTIVITY IS EXPECTED
TO OCCUR TO THE SOUTH AND SOUTHWEST. WILL MAINTAIN A TEMPO GROUP
FROM 19-22Z FOR MVFR TSRA CONDITIONS TO COVER. LOW CIGS ARE POSSIBLE
AGAIN TONIGHT AND SUB-VFR CONDITIONS MAY NEED TO BE INTRODUCED IN
LATER FORECAST CYCLES.

KSAV...A BRIEF STINT OF LIFR CIGS HAVE UNEXPECTEDLY INFILTRATED
THE TERMINAL. EXPECT THESE CONDITIONS WILL BE BRIEF WITH THE
STATIONARY FRONT STILL TO THE NORTH. EXPECT IMPROVING CONDITIONS
TO VFR AFTER 14-15Z. HIGH RESOLUTION MODELS CONTINUE TO PING MUCH
OF SOUTHEAST GEORGIA FOR WIDESPREAD SHOWER/TSTMS. WILL INTRODUCE
PREVAILING MVFR TSRA CONDITIONS BEGINNING AT 19Z WITH TEMPO IFR
VSBYS FROM 19-22Z TO COVER. RISK FOR TSTM IMPACTS SHOULD PASS TO
THE WEST OF THE TERMINAL BY SUNSET. LOW CIGS ARE POSSIBLE AGAIN
TONIGHT AND SUB-VFR CONDITIONS MAY NEED TO BE INTRODUCED IN LATER
FORECAST CYCLES.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.

TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE A ROUND OF SLOW MOVING SHOWERS/TSTMS AFFECTING THE
AREA TODAY. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN
PRODUCERS WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES
IN EXCESS OF 2-3 IN/HR. THE LATEST 1-HR FLASH FLOOD GUIDANCE
VALUES ARE VERY NEAR THESE RATES...SO BELIEVE THERE IS A ENOUGH OF
A RISK FOR FLASH FLOODING OVER A LARGE ENOUGH AREA TO JUSTIFY A
FLASH FLOOD WATCH THROUGH LATE EVENING. IN ADDITION...SOME AREAS
SAW RAIN AMOUNTS IN EXCESS OF 4-5 INCHES WITH A LARGE AREA OF 2-3
INCHES...ESPECIALLY ACROSS INTERIOR SOUTHEAST GEORGIA. WITH THE
GROUND SATURATED IN THESE AREAS...IT WILL NOT TAKE LONG FOR FLASH
FLOODING TO OCCUR. RAINFALL AMOUNTS WILL AVERAGE 1-2 INCHES
THROUGH TONIGHT WITH ISOLATED AMOUNTS RUNNING IN EXCESS OF 5-6
INCHES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
     114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
     047>052.
MARINE...NONE.

&&

$$

ST/WMS






000
FXUS62 KCHS 151119
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
719 AM EDT MON SEP 15 2014

...LOCALLY HEAVY RAINFALL AND FLASH FLOODING POSSIBLE THIS
AFTERNOON AND EVENING...

.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 15/10Z...THE STATIONARY FRONT WAS ROUGHLY POSITIONED ALONG A
MILLEN-NEWINGTON-RIDGEVILLE-SEABROOK ISLAND LINE PER LATEST
RAP INSTABILITY PLOTS AND SURFACE OBSERVATION. FOR THE EARLY
MORNING UPDATE...

1. STRATUS BUILD DOWN HAS RESULTED IN SOME LOW VSBYS NORTH OF THE
STATIONARY FRONT EARLY THIS MORNING. THE FOG HAS BECOME LOCALLY
DENSE WHERE CIGS HAVE DROPPED BELOW 100 FT AT TIMES. A SPECIAL
WEATHER STATEMENT HAS BEEN ISSUED TO HANDLE THIS THROUGH 830 AM.
A DENSE FOG ADVISORY IS NOT ANTICIPATED...BUT CONDITIONS WILL
CONTINUE TO BE CLOSELY MONITORED.

2. HIGH RESOLUTION MODELS CONTINUE TO KEY IN ON THE CORRIDOR
ROUGHLY BOUNDED BY STATESBORO...SAVANNAH...DARIEN AND GLENNVILLE
FOR THE MOST SIGNIFICANT HEAVY RAINS TODAY. POPS HAVE BEEN
INCREASED IN THIS AREA TO CATEGORICAL...80 PERCENT...TO COVER.
THERE REMAINS A RISK FOR FLASH FLOODING JUST ABOUT ANYWHERE TODAY.

TODAY...THE SYNOPTIC PATTERN CONTINUES TO FAVOR A HEAVY RAIN
SETUP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
WEAK STATIONARY FRONT THAT IS CURRENTLY BISECTING THE FORECAST
AREA IS FORECAST TO GRADUALLY WASH OUT THIS AFTERNOON AS BROAD
PRESSURE FALLS AHEAD OF POWERFUL SHORTWAVE ENERGY DIGGING INTO THE
OHIO VALLEY OVERSPREAD THE REGION. THE UPPER JET CONFIGURATION
REMAINS IN A FAVORABLE ORIENTATION FOR UPPER SUPPORT WITH THE
RIGHT ENTRANCE REGION FORECAST OR PROVIDE ANOTHER CORRIDOR OF
ENHANCED UPPER DIVERGENCE ATOP THE DECAYING FRONT AND SEA BREEZE
CIRCULATION DURING PEAK HEATING. MOST OF THE HIGH RESOLUTION
MODELS ARE SHOWING A SIGNAL FOR A CORRIDOR OF TORRENTIAL RAINS TO
SETUP ALONG THE I-95 CORRIDOR BY EARLY-MID AFTERNOON...POSSIBLY
INITIATING ALONG THE GEORGIA COAST...THEN GRADUALLY SPREADING
INLAND AND TO THE NORTH WITH THE SEA BREEZE. RAINFALL AMOUNTS OF
2 INCHES WITH LOCALLY HIGHER AMOUNTS IN EXCESS OF 5 INCHES WILL BE
POSSIBLE WITH SMALL MEAN STORM MOTION VECTORS AND ANOMALOUSLY HIGH
TROPOSPHERIC MOISTURE IN PLACE. SEE THE HYDROLOGY SECTION BELOW ON
INFORMATION ADDRESSING THE POTENTIAL FOR FLASH FLOODING.

POPS WILL BE INCREASED TO 60-70 PERCENT FOR MOST AREAS TODAY...
MAINLY DURING THE AFTERNOON HOURS. MUCH OF THE MORNING MAY
ACTUALLY BE FAIRLY QUIET...BUT AS THE FRONT BEGINS TO WASHES OUT
AND INSTABILITY INCREASES...EXPECT CONVECTIVE INITIATION TO OCCUR
BY EARLY AFTERNOON. SEVERAL GUIDANCE MEMBERS SUGGEST CATEGORICAL
POPS MAY EVENTUALLY BE NEEDED...WHICH WILL NEED TO BE CONSIDERED
LATER TODAY ONCE MESOSCALE CONVECTIVE TRENDS BECOME MORE APPARENT.
HIGHS WILL RANGE FROM THE MID 80S NORTH TO THE UPPER 80S ROUGHLY
SOUTH OF I-16.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.

TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.

DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.

WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
KCHS...LOW-END IFR CIGS WILL LINGER THROUGH ABOUT 15Z WITH
IMPROVING CONDITIONS TO VFR THEREAFTER. HIGH RESOLUTION MODELS
STILL SUGGEST THERE WILL BE AN ELEVATED RISK FOR TSTM IMPACTS AT
THE TERMINAL TODAY...ALTHOUGH THE BULK OF THE ACTIVITY IS EXPECTED
TO OCCUR TO THE SOUTH AND SOUTHWEST. WILL MAINTAIN A TEMPO GROUP
FROM 19-22Z FOR MVFR TSRA CONDITIONS TO COVER. LOW CIGS ARE POSSIBLE
AGAIN TONIGHT AND SUB-VFR CONDITIONS MAY NEED TO BE INTRODUCED IN
LATER FORECAST CYCLES.

KSAV...A BRIEF STINT OF LIFR CIGS HAVE UNEXPECTEDLY INFILTRATED
THE TERMINAL. EXPECT THESE CONDITIONS WILL BE BRIEF WITH THE
STATIONARY FRONT STILL TO THE NORTH. EXPECT IMPROVING CONDITIONS
TO VFR AFTER 14-15Z. HIGH RESOLUTION MODELS CONTINUE TO PING MUCH
OF SOUTHEAST GEORGIA FOR WIDESPREAD SHOWER/TSTMS. WILL INTRODUCE
PREVAILING MVFR TSRA CONDITIONS BEGINNING AT 19Z WITH TEMPO IFR
VSBYS FROM 19-22Z TO COVER. RISK FOR TSTM IMPACTS SHOULD PASS TO
THE WEST OF THE TERMINAL BY SUNSET. LOW CIGS ARE POSSIBLE AGAIN
TONIGHT AND SUB-VFR CONDITIONS MAY NEED TO BE INTRODUCED IN LATER
FORECAST CYCLES.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.

TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE A ROUND OF SLOW MOVING SHOWERS/TSTMS AFFECTING THE
AREA TODAY. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN
PRODUCERS WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES
IN EXCESS OF 2-3 IN/HR. THE LATEST 1-HR FLASH FLOOD GUIDANCE
VALUES ARE VERY NEAR THESE RATES...SO BELIEVE THERE IS A ENOUGH OF
A RISK FOR FLASH FLOODING OVER A LARGE ENOUGH AREA TO JUSTIFY A
FLASH FLOOD WATCH THROUGH LATE EVENING. IN ADDITION...SOME AREAS
SAW RAIN AMOUNTS IN EXCESS OF 4-5 INCHES WITH A LARGE AREA OF 2-3
INCHES...ESPECIALLY ACROSS INTERIOR SOUTHEAST GEORGIA. WITH THE
GROUND SATURATED IN THESE AREAS...IT WILL NOT TAKE LONG FOR FLASH
FLOODING TO OCCUR. RAINFALL AMOUNTS WILL AVERAGE 1-2 INCHES
THROUGH TONIGHT WITH ISOLATED AMOUNTS RUNNING IN EXCESS OF 5-6
INCHES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
     114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
     047>052.
MARINE...NONE.

&&

$$

ST/WMS





000
FXUS62 KCHS 150809
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
409 AM EDT MON SEP 15 2014

...LOCALLY HEAVY RAINFALL AND FLASH FLOODING POSSIBLE THIS
AFTERNOON AND EVENING...

.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
THROUGH SUNRISE...15/07Z RAP INSTABILITY ANALYSIS SHOWED THE
STATIONARY FRONT EXTENDED FROM ROUGHLY MILLEN GEORGIA TO
ESTILL...HENDERSONVILLE TO FOLLY BEACH IN SOUTH CAROLINA. NORTH
OF THE FRONT...WIDESPREAD STRATUS AND EVEN SOME FOG HAS DEVELOPED
WITH DEWPOINTS IN THE UPPER 60S...WHILE SOUTH OF THE FRONT
CEILINGS ARE CONSIDERABLY HIGHER WITH DEWPOINTS RUNNING IN THE
LOWER-MID 70S. THE WEAKENING FRONT WILL MOVE LITTLE THROUGH
SUNRISE...POSSIBLY DRIFTING EVER SO SLIGHTLY TO THE SOUTH WITH
VERY WEAK PRESSURE RISES STILL NOTED OVER EASTERN NORTH CAROLINA.
SUBTLE COASTAL CONVERGENCE ALONG THE COAST COULD PRODUCE ISOLATED
TO PERHAPS SCATTERED SHOWERS/TSTMS OVER THE NEXT FEW HOURS...
MAINLY FROM TYBEE ISLAND NORTH WHERE SURFACE MOISTURE FLUX
CONVERGENCE IS INCREASING. THE FOG NORTH OF THE FRONT HAS NOT BEEN
SIGNIFICANT SO FAR...BUT THERE IS A POSSIBILITY THAT STRATUS BUILD
DOWN PROCESSES COULD PRODUCE AT LEAST SOME POCKETS OF LOCALLY
DENSE FOG. TRENDS WILL BE WATCHED CAREFULLY ACROSS THE NORTHERN
ZONES...BUT A DENSE FOG ADVISORY IS NOT ANTICIPATED ATTM.

TODAY...THE SYNOPTIC PATTERN CONTINUES TO FAVOR A HEAVY RAIN
SETUP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
WEAK STATIONARY FRONT THAT IS CURRENTLY BISECTING THE FORECAST
AREA IS FORECAST TO GRADUALLY WASH OUT THIS AFTERNOON AS BROAD
PRESSURE FALLS AHEAD OF POWERFUL SHORTWAVE ENERGY DIGGING INTO THE
OHIO VALLEY OVERSPREAD THE REGION. THE UPPER JET CONFIGURATION
REMAINS IN A FAVORABLE ORIENTATION FOR UPPER SUPPORT WITH THE
RIGHT ENTRANCE REGION FORECAST OR PROVIDE ANOTHER CORRIDOR OF
ENHANCED UPPER DIVERGENCE ATOP THE DECAYING FRONT AND SEA BREEZE
CIRCULATION DURING PEAK HEATING. MOST OF THE HIGH RESOLUTION
MODELS ARE SHOWING A SIGNAL FOR A CORRIDOR OF TORRENTIAL RAINS TO
SETUP ALONG THE I-95 CORRIDOR BY EARLY-MID AFTERNOON...POSSIBLY
INITIATING ALONG THE GEORGIA COAST...THEN GRADUALLY SPREADING
INLAND AND TO THE NORTH WITH THE SEA BREEZE. RAINFALL AMOUNTS OF
2 INCHES WITH LOCALLY HIGHER AMOUNTS IN EXCESS OF 5 INCHES WILL BE
POSSIBLE WITH SMALL MEAN STORM MOTION VECTORS AND ANOMALOUSLY HIGH
TROPOSPHERIC MOISTURE IN PLACE. SEE THE HYDROLOGY SECTION BELOW ON
INFORMATION ADDRESSING THE POTENTIAL FOR FLASH FLOODING.

POPS WILL BE INCREASED TO 60-70 PERCENT FOR MOST AREAS TODAY...
MAINLY DURING THE AFTERNOON HOURS. MUCH OF THE MORNING MAY
ACTUALLY BE FAIRLY QUIET...BUT AS THE FRONT BEGINS TO WASHES OUT
AND INSTABILITY INCREASES...EXPECT CONVECTIVE INITIATION TO OCCUR
BY EARLY AFTERNOON. SEVERAL GUIDANCE MEMBERS SUGGEST CATEGORICAL
POPS MAY EVENTUALLY BE NEEDED...WHICH WILL NEED TO BE CONSIDERED
LATER TODAY ONCE MESOSCALE CONVECTIVE TRENDS BECOME MORE APPARENT.
HIGHS WILL RANGE FROM THE MID 80S NORTH TO THE UPPER 80S ROUGHLY
SOUTH OF I-16.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.

TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.

DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.

WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
KCHS...THE TERMINAL REMAINS SOUTH OF THE STATIONARY FRONT. IFR
CIGS ARE BECOMING MORE WIDESPREAD AND WILL LINGER THROUGH SUNRISE.
THERE IS ABOUT A 40 PERCENT CHANCE THAT LIFR CIGS WILL
DEVELOP...BUT MODEL TRENDS ARE NOT SHOWING A DEFINITIVE TREND AT
THIS POINT. WILL SHOW PREVAILING LOW-END IFR THROUGH 12-13Z WITH
CONDITIONS IMPROVING TO MVFR THEREAFTER WITH VFR CIGS BY 18Z.
SHOWERS/TSTMS ARE LIKELY AGAIN TODAY...BUT ITS UNCLEAR WHEN TSTMS
IMPACTS WILL OCCUR. BEST CHANCES ATTM APPEAR TO BE IN THE 19-22Z
TIME FRAME...BUT THIS WILL NEED TO BE REFINED AS THE DAY
PROGRESSES.

KSAV...THE STATIONARY FRONT REMAINS IN THE VCNTY OF THE TERMINAL.
IFR CIGS ARE NOT TOO FAR AND EXPECT VFR CIGS TO LOWER TO IFR
THRESHOLDS BY 09Z. SOME LIGHT FOG MAY ALSO OCCUR...BUT THE BETTER
CHANCES FOR FOG IMPACTS LOOK TO REMAIN TO THE NORTH AND WEST OF
THE TERMINAL. IFR CIGS WILL LINGER THROUGH SUNRISE WITH CIGS
LIVING TO MVFR BY 13Z AND VFR BY 16Z. BEST CHANCES FOR TSTM
IMPACTS TODAY WILL BE 17-20Z TIME FRAME...BUT THIS WILL NEED TO BE
REFINED AS THE DAY PROGRESSES.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.

TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE A ROUND OF SLOW MOVING SHOWERS/TSTMS AFFECTING THE
AREA TODAY. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN
PRODUCERS WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES
IN EXCESS OF 2-3 IN/HR. THE LATEST 1-HR FLASH FLOOD GUIDANCE
VALUES ARE VERY NEAR THESE RATES...SO BELIEVE THERE IS A ENOUGH OF
A RISK FOR FLASH FLOODING OVER A LARGE ENOUGH AREA TO JUSTIFY A
FLASH FLOOD WATCH THROUGH LATE EVENING. IN ADDITION...SOME AREAS
SAW RAIN AMOUNTS IN EXCESS OF 4-5 INCHES WITH A LARGE AREA OF 2-3
INCHES...ESPECIALLY ACROSS INTERIOR SOUTHEAST GEORGIA. WITH THE
GROUND SATURATED IN THESE AREAS...IT WILL NOT TAKE LONG FOR FLASH
FLOODING TO OCCUR. RAINFALL AMOUNTS WILL AVERAGE 1-2 INCHES
THROUGH TONIGHT WITH ISOLATED AMOUNTS RUNNING IN EXCESS OF 5-6
INCHES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
     114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
     047>052.
MARINE...NONE.

&&

$$

ST/WMS





000
FXUS62 KCHS 150809
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
409 AM EDT MON SEP 15 2014

...LOCALLY HEAVY RAINFALL AND FLASH FLOODING POSSIBLE THIS
AFTERNOON AND EVENING...

.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
THROUGH SUNRISE...15/07Z RAP INSTABILITY ANALYSIS SHOWED THE
STATIONARY FRONT EXTENDED FROM ROUGHLY MILLEN GEORGIA TO
ESTILL...HENDERSONVILLE TO FOLLY BEACH IN SOUTH CAROLINA. NORTH
OF THE FRONT...WIDESPREAD STRATUS AND EVEN SOME FOG HAS DEVELOPED
WITH DEWPOINTS IN THE UPPER 60S...WHILE SOUTH OF THE FRONT
CEILINGS ARE CONSIDERABLY HIGHER WITH DEWPOINTS RUNNING IN THE
LOWER-MID 70S. THE WEAKENING FRONT WILL MOVE LITTLE THROUGH
SUNRISE...POSSIBLY DRIFTING EVER SO SLIGHTLY TO THE SOUTH WITH
VERY WEAK PRESSURE RISES STILL NOTED OVER EASTERN NORTH CAROLINA.
SUBTLE COASTAL CONVERGENCE ALONG THE COAST COULD PRODUCE ISOLATED
TO PERHAPS SCATTERED SHOWERS/TSTMS OVER THE NEXT FEW HOURS...
MAINLY FROM TYBEE ISLAND NORTH WHERE SURFACE MOISTURE FLUX
CONVERGENCE IS INCREASING. THE FOG NORTH OF THE FRONT HAS NOT BEEN
SIGNIFICANT SO FAR...BUT THERE IS A POSSIBILITY THAT STRATUS BUILD
DOWN PROCESSES COULD PRODUCE AT LEAST SOME POCKETS OF LOCALLY
DENSE FOG. TRENDS WILL BE WATCHED CAREFULLY ACROSS THE NORTHERN
ZONES...BUT A DENSE FOG ADVISORY IS NOT ANTICIPATED ATTM.

TODAY...THE SYNOPTIC PATTERN CONTINUES TO FAVOR A HEAVY RAIN
SETUP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
WEAK STATIONARY FRONT THAT IS CURRENTLY BISECTING THE FORECAST
AREA IS FORECAST TO GRADUALLY WASH OUT THIS AFTERNOON AS BROAD
PRESSURE FALLS AHEAD OF POWERFUL SHORTWAVE ENERGY DIGGING INTO THE
OHIO VALLEY OVERSPREAD THE REGION. THE UPPER JET CONFIGURATION
REMAINS IN A FAVORABLE ORIENTATION FOR UPPER SUPPORT WITH THE
RIGHT ENTRANCE REGION FORECAST OR PROVIDE ANOTHER CORRIDOR OF
ENHANCED UPPER DIVERGENCE ATOP THE DECAYING FRONT AND SEA BREEZE
CIRCULATION DURING PEAK HEATING. MOST OF THE HIGH RESOLUTION
MODELS ARE SHOWING A SIGNAL FOR A CORRIDOR OF TORRENTIAL RAINS TO
SETUP ALONG THE I-95 CORRIDOR BY EARLY-MID AFTERNOON...POSSIBLY
INITIATING ALONG THE GEORGIA COAST...THEN GRADUALLY SPREADING
INLAND AND TO THE NORTH WITH THE SEA BREEZE. RAINFALL AMOUNTS OF
2 INCHES WITH LOCALLY HIGHER AMOUNTS IN EXCESS OF 5 INCHES WILL BE
POSSIBLE WITH SMALL MEAN STORM MOTION VECTORS AND ANOMALOUSLY HIGH
TROPOSPHERIC MOISTURE IN PLACE. SEE THE HYDROLOGY SECTION BELOW ON
INFORMATION ADDRESSING THE POTENTIAL FOR FLASH FLOODING.

POPS WILL BE INCREASED TO 60-70 PERCENT FOR MOST AREAS TODAY...
MAINLY DURING THE AFTERNOON HOURS. MUCH OF THE MORNING MAY
ACTUALLY BE FAIRLY QUIET...BUT AS THE FRONT BEGINS TO WASHES OUT
AND INSTABILITY INCREASES...EXPECT CONVECTIVE INITIATION TO OCCUR
BY EARLY AFTERNOON. SEVERAL GUIDANCE MEMBERS SUGGEST CATEGORICAL
POPS MAY EVENTUALLY BE NEEDED...WHICH WILL NEED TO BE CONSIDERED
LATER TODAY ONCE MESOSCALE CONVECTIVE TRENDS BECOME MORE APPARENT.
HIGHS WILL RANGE FROM THE MID 80S NORTH TO THE UPPER 80S ROUGHLY
SOUTH OF I-16.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.

TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.

DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.

WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
KCHS...THE TERMINAL REMAINS SOUTH OF THE STATIONARY FRONT. IFR
CIGS ARE BECOMING MORE WIDESPREAD AND WILL LINGER THROUGH SUNRISE.
THERE IS ABOUT A 40 PERCENT CHANCE THAT LIFR CIGS WILL
DEVELOP...BUT MODEL TRENDS ARE NOT SHOWING A DEFINITIVE TREND AT
THIS POINT. WILL SHOW PREVAILING LOW-END IFR THROUGH 12-13Z WITH
CONDITIONS IMPROVING TO MVFR THEREAFTER WITH VFR CIGS BY 18Z.
SHOWERS/TSTMS ARE LIKELY AGAIN TODAY...BUT ITS UNCLEAR WHEN TSTMS
IMPACTS WILL OCCUR. BEST CHANCES ATTM APPEAR TO BE IN THE 19-22Z
TIME FRAME...BUT THIS WILL NEED TO BE REFINED AS THE DAY
PROGRESSES.

KSAV...THE STATIONARY FRONT REMAINS IN THE VCNTY OF THE TERMINAL.
IFR CIGS ARE NOT TOO FAR AND EXPECT VFR CIGS TO LOWER TO IFR
THRESHOLDS BY 09Z. SOME LIGHT FOG MAY ALSO OCCUR...BUT THE BETTER
CHANCES FOR FOG IMPACTS LOOK TO REMAIN TO THE NORTH AND WEST OF
THE TERMINAL. IFR CIGS WILL LINGER THROUGH SUNRISE WITH CIGS
LIVING TO MVFR BY 13Z AND VFR BY 16Z. BEST CHANCES FOR TSTM
IMPACTS TODAY WILL BE 17-20Z TIME FRAME...BUT THIS WILL NEED TO BE
REFINED AS THE DAY PROGRESSES.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.

&&

.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.

TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.

RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.

&&

.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE A ROUND OF SLOW MOVING SHOWERS/TSTMS AFFECTING THE
AREA TODAY. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN
PRODUCERS WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES
IN EXCESS OF 2-3 IN/HR. THE LATEST 1-HR FLASH FLOOD GUIDANCE
VALUES ARE VERY NEAR THESE RATES...SO BELIEVE THERE IS A ENOUGH OF
A RISK FOR FLASH FLOODING OVER A LARGE ENOUGH AREA TO JUSTIFY A
FLASH FLOOD WATCH THROUGH LATE EVENING. IN ADDITION...SOME AREAS
SAW RAIN AMOUNTS IN EXCESS OF 4-5 INCHES WITH A LARGE AREA OF 2-3
INCHES...ESPECIALLY ACROSS INTERIOR SOUTHEAST GEORGIA. WITH THE
GROUND SATURATED IN THESE AREAS...IT WILL NOT TAKE LONG FOR FLASH
FLOODING TO OCCUR. RAINFALL AMOUNTS WILL AVERAGE 1-2 INCHES
THROUGH TONIGHT WITH ISOLATED AMOUNTS RUNNING IN EXCESS OF 5-6
INCHES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
     114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
     047>052.
MARINE...NONE.

&&

$$

ST/WMS






000
FXUS62 KCHS 150506
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
106 AM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT OVER THE AREA WILL WAVER SOUTH OVERNIGHT. THE
FRONT WILL GRADUALLY DISSIPATE MONDAY. A PRE-FRONTAL TROUGH WILL
MOVE IN TUESDAY....THEN A STRONGER COLD FRONT IS FORECAST TO PUSH
THROUGH THE REGION DURING THE MIDDLE OF THE WEEK. A STRONG INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO
NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE STATIONARY FRONT ESSENTIALLY BISECTS THE FORECAST AREA EARLY
THIS MORNING. NORTH OF THE FRONT...LOW CLOUDS ARE BECOMING MORE
PREVALENT WHILE SOUTH MID/HIGH-LEVEL CLOUDS REMAIN EXTENSIVE. LOW
CLOUDS AND POSSIBLY SOME FOG WILL MEANDER SOUTH OVER THE NEXT FEW
HOURS...POSSIBLY AS FAR SOUTH AS THE I-16 CORRIDOR PRIOR TO
SUNRISE. THERE IS A CHANCE THAT STATUS BUILD-DOWN COULD YIELD SOME
LOCALLY DENSE FOG...SO VSBY TRENDS WILL BE WATCHED CAREFULLY.
OTHERWISE...LINGERING SHOWER ACTIVITY WILL GRADUALLY DIMINISH...
BUT SHOWERS/TSTMS COULD POP JUST ABOUT ANYTIME DURING THE
OVERNIGHT HOURS WITH SUCH AS MOIST ATMOSPHERE IN PLACE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREA WIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS USN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
KCHS...THE TERMINAL REMAINS SOUTH OF THE STATIONARY FRONT. IFR
CIGS ARE BECOMING MORE WIDESPREAD AND WILL LINGER THROUGH SUNRISE.
THERE IS ABOUT A 40 PERCENT CHANCE THAT LIFR CIGS WILL
DEVELOP...BUT MODEL TRENDS ARE NOT SHOWING A DEFINITIVE TREND AT
THIS POINT. WILL SHOW PREVAILING LOW-END IFR THROUGH 12-13Z WITH
CONDITIONS IMPROVING TO MVFR THEREAFTER WITH VFR CIGS BY 18Z.
SHOWERS/TSTMS ARE LIKELY AGAIN TODAY...BUT ITS UNCLEAR WHEN TSTMS
IMPACTS WILL OCCUR. BEST CHANCES ATTM APPEAR TO BE IN THE 19-22Z
TIME FRAME...BUT THIS WILL NEED TO BE REFINED AS THE DAY
PROGRESSES.

KSAV...THE STATIONARY FRONT REMAINS IN THE VCNTY OF THE TERMINAL.
IFR CIGS ARE NOT TOO FAR AND EXPECT VFR CIGS TO LOWER TO IFR
THRESHOLDS BY 09Z. SOME LIGHT FOG MAY ALSO OCCUR...BUT THE BETTER
CHANCES FOR FOG IMPACTS LOOK TO REMAIN TO THE NORTH AND WEST OF
THE TERMINAL. IFR CIGS WILL LINGER THROUGH SUNRISE WITH CIGS
LIVING TO MVFR BY 13Z AND VFR BY 16Z. BEST CHANCES FOR TSTM
IMPACTS TODAY WILL BE 17-20Z TIME FRAME...BUT THIS WILL NEED TO BE
REFINED AS THE DAY PROGRESSES.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON
AND EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW
STRATUS AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
OVERNIGHT...A STATIONARY FRONT WILL WAVER SLIGHTLY SOUTH INTO GA
WATERS. NORTH OF THE FRONT...NE WINDS 5-15 KT WILL PREVAIL...WHILE
S/SE WINDS AT SIMILAR SPEEDS WILL PREVAIL SOUTH OF THE FRONT.
CLOSE TO THE FRONT...VARIABLE WINDS WILL REMAIN LESS THAN 10
KT...AND CONDITIONS WILL BE FAVORABLE FOR ISOLATED WATERSPOUTS.
OUTSIDE ANY THUNDERSTORMS...SEAS 1-3 FT WILL PREVAIL OVERNIGHT.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

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

&&

$$

ST






000
FXUS62 KCHS 150506
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
106 AM EDT MON SEP 15 2014

.SYNOPSIS...
A STATIONARY FRONT OVER THE AREA WILL WAVER SOUTH OVERNIGHT. THE
FRONT WILL GRADUALLY DISSIPATE MONDAY. A PRE-FRONTAL TROUGH WILL
MOVE IN TUESDAY....THEN A STRONGER COLD FRONT IS FORECAST TO PUSH
THROUGH THE REGION DURING THE MIDDLE OF THE WEEK. A STRONG INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO
NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE STATIONARY FRONT ESSENTIALLY BISECTS THE FORECAST AREA EARLY
THIS MORNING. NORTH OF THE FRONT...LOW CLOUDS ARE BECOMING MORE
PREVALENT WHILE SOUTH MID/HIGH-LEVEL CLOUDS REMAIN EXTENSIVE. LOW
CLOUDS AND POSSIBLY SOME FOG WILL MEANDER SOUTH OVER THE NEXT FEW
HOURS...POSSIBLY AS FAR SOUTH AS THE I-16 CORRIDOR PRIOR TO
SUNRISE. THERE IS A CHANCE THAT STATUS BUILD-DOWN COULD YIELD SOME
LOCALLY DENSE FOG...SO VSBY TRENDS WILL BE WATCHED CAREFULLY.
OTHERWISE...LINGERING SHOWER ACTIVITY WILL GRADUALLY DIMINISH...
BUT SHOWERS/TSTMS COULD POP JUST ABOUT ANYTIME DURING THE
OVERNIGHT HOURS WITH SUCH AS MOIST ATMOSPHERE IN PLACE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREA WIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS USN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
KCHS...THE TERMINAL REMAINS SOUTH OF THE STATIONARY FRONT. IFR
CIGS ARE BECOMING MORE WIDESPREAD AND WILL LINGER THROUGH SUNRISE.
THERE IS ABOUT A 40 PERCENT CHANCE THAT LIFR CIGS WILL
DEVELOP...BUT MODEL TRENDS ARE NOT SHOWING A DEFINITIVE TREND AT
THIS POINT. WILL SHOW PREVAILING LOW-END IFR THROUGH 12-13Z WITH
CONDITIONS IMPROVING TO MVFR THEREAFTER WITH VFR CIGS BY 18Z.
SHOWERS/TSTMS ARE LIKELY AGAIN TODAY...BUT ITS UNCLEAR WHEN TSTMS
IMPACTS WILL OCCUR. BEST CHANCES ATTM APPEAR TO BE IN THE 19-22Z
TIME FRAME...BUT THIS WILL NEED TO BE REFINED AS THE DAY
PROGRESSES.

KSAV...THE STATIONARY FRONT REMAINS IN THE VCNTY OF THE TERMINAL.
IFR CIGS ARE NOT TOO FAR AND EXPECT VFR CIGS TO LOWER TO IFR
THRESHOLDS BY 09Z. SOME LIGHT FOG MAY ALSO OCCUR...BUT THE BETTER
CHANCES FOR FOG IMPACTS LOOK TO REMAIN TO THE NORTH AND WEST OF
THE TERMINAL. IFR CIGS WILL LINGER THROUGH SUNRISE WITH CIGS
LIVING TO MVFR BY 13Z AND VFR BY 16Z. BEST CHANCES FOR TSTM
IMPACTS TODAY WILL BE 17-20Z TIME FRAME...BUT THIS WILL NEED TO BE
REFINED AS THE DAY PROGRESSES.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON
AND EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW
STRATUS AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
OVERNIGHT...A STATIONARY FRONT WILL WAVER SLIGHTLY SOUTH INTO GA
WATERS. NORTH OF THE FRONT...NE WINDS 5-15 KT WILL PREVAIL...WHILE
S/SE WINDS AT SIMILAR SPEEDS WILL PREVAIL SOUTH OF THE FRONT.
CLOSE TO THE FRONT...VARIABLE WINDS WILL REMAIN LESS THAN 10
KT...AND CONDITIONS WILL BE FAVORABLE FOR ISOLATED WATERSPOUTS.
OUTSIDE ANY THUNDERSTORMS...SEAS 1-3 FT WILL PREVAIL OVERNIGHT.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

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

&&

$$

ST





000
FXUS62 KCHS 150309
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1109 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT OVER THE AREA WILL WAVER SOUTH OVERNIGHT. THE
FRONT WILL GRADUALLY DISSIPATE MONDAY. A PRE-FRONTAL TROUGH WILL
MOVE IN TUESDAY....THEN A STRONGER COLD FRONT IS FORECAST TO PUSH
THROUGH THE REGION DURING THE MIDDLE OF THE WEEK. A STRONG INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO
NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
DISCONTINUED REMAINDER OF FLASH FLOOD WATCH. NUMEROUS
SHOWERS/SCATTERED THUNDERSTORMS NEAR STATIONARY FRONT FROM
EFFINGHAM/JASPER EAST THROUGH BEAUFORT/SOUTHERN COLLETON SHOULD
CONTINUE TO GRADUALLY DIMINISH IN COVERAGE/INTENSITY...AND
ASSOCIATED POPS SHOULD DECREASE TO CHANCE IN THIS CORRIDOR DURING
THE NEXT COUPLE OF HOURS. WILL CONTINUE TO ASSESS POTENTIAL FOR
OUTFLOW TO PRODUCE ADDITIONAL SHOWERS AS FAR EAST AS THE
CHARLESTON TRI-COUNTY AREA OVERNIGHT.

OTHERWISE...SLIGHT CHANCE TO CHANCE POPS REMAIN IN ORDER
OVERNIGHT...HIGHEST ALONG THE QUASI-STATIONARY FRONT WHICH LATEST
GUIDANCE SUGGESTS WILL SHIFT A BIT FARTHER SOUTH BETWEEN I-16 AND
THE ALTAMAHA RIVER DUE TO BUILDING HIGH PRESSURE TO THE NORTH AND
THUNDERSTORM OUTFLOW.

ALSO OF NOTE...LOWERING STRATUS COULD SUPPORT FOG ALONG/NORTH OF THE
FRONT OVERNIGHT.

LOWS SHOULD GENERALLY RANGE FROM THE UPPER 60S NORTH AND WEST TO
LOWER TO MID 70S SOUTH AND EAST...POSSIBLY SOME UPPER 70S/NEAR 80F
FROM HXD SOUTH ALONG THE GA COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AT KCHS...MVFR/IFR CEILINGS WILL PREVAIL THROUGH MONDAY. A PERIOD
OF LIFR CEILINGS ARE POSSIBLE LATE TONIGHT INTO MONDAY MORNING. AT
KSAV...VFR CONDITIONS SHOULD GIVE WAY TO MVFR/IFR CEILINGS LATER
TONIGHT...BUT TIMING REMAINS UNCERTAIN. ONCE SUB-VFR CEILINGS
DEVELOP THESE CONDITIONS WILL PREVAIL THROUGH MOST OF MONDAY WITH
ONLY BRIEF IMPROVEMENT TO VFR POSSIBLE MONDAY AFTERNOON. AT BOTH
SITES...00Z TAFS INDICATE VCSH UNTIL LATER TONIGHT. THEN...SHOWERS/
THUNDERSTORMS ARE LIKELY AT BOTH SITES ESPECIALLY MONDAY
AFTERNOON. HOWEVER...DUE TO UNCERTAINTY REGARDING WORST CONDITIONS
OPTED FOR PREVAILING -SHRA AND VCTS/CBS AT BOTH TERMINALS MONDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
OVERNIGHT...A STATIONARY FRONT WILL WAVER SLIGHTLY SOUTH INTO GA
WATERS. NORTH OF THE FRONT...NE WINDS 5-15 KT WILL PREVAIL...WHILE
S/SE WINDS AT SIMILAR SPEEDS WILL PREVAIL SOUTH OF THE FRONT.
CLOSE TO THE FRONT...VARIABLE WINDS WILL REMAIN LESS THAN 10
KT...AND CONDITIONS WILL BE FAVORABLE FOR ISOLATED WATERSPOUTS.
OUTSIDE ANY THUNDERSTORMS...SEAS 1-3 FT WILL PREVAIL OVERNIGHT.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

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

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...
AVIATION...33/SPR
MARINE...33/SPR







000
FXUS62 KCHS 150309
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1109 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT OVER THE AREA WILL WAVER SOUTH OVERNIGHT. THE
FRONT WILL GRADUALLY DISSIPATE MONDAY. A PRE-FRONTAL TROUGH WILL
MOVE IN TUESDAY....THEN A STRONGER COLD FRONT IS FORECAST TO PUSH
THROUGH THE REGION DURING THE MIDDLE OF THE WEEK. A STRONG INLAND
WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO
NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
DISCONTINUED REMAINDER OF FLASH FLOOD WATCH. NUMEROUS
SHOWERS/SCATTERED THUNDERSTORMS NEAR STATIONARY FRONT FROM
EFFINGHAM/JASPER EAST THROUGH BEAUFORT/SOUTHERN COLLETON SHOULD
CONTINUE TO GRADUALLY DIMINISH IN COVERAGE/INTENSITY...AND
ASSOCIATED POPS SHOULD DECREASE TO CHANCE IN THIS CORRIDOR DURING
THE NEXT COUPLE OF HOURS. WILL CONTINUE TO ASSESS POTENTIAL FOR
OUTFLOW TO PRODUCE ADDITIONAL SHOWERS AS FAR EAST AS THE
CHARLESTON TRI-COUNTY AREA OVERNIGHT.

OTHERWISE...SLIGHT CHANCE TO CHANCE POPS REMAIN IN ORDER
OVERNIGHT...HIGHEST ALONG THE QUASI-STATIONARY FRONT WHICH LATEST
GUIDANCE SUGGESTS WILL SHIFT A BIT FARTHER SOUTH BETWEEN I-16 AND
THE ALTAMAHA RIVER DUE TO BUILDING HIGH PRESSURE TO THE NORTH AND
THUNDERSTORM OUTFLOW.

ALSO OF NOTE...LOWERING STRATUS COULD SUPPORT FOG ALONG/NORTH OF THE
FRONT OVERNIGHT.

LOWS SHOULD GENERALLY RANGE FROM THE UPPER 60S NORTH AND WEST TO
LOWER TO MID 70S SOUTH AND EAST...POSSIBLY SOME UPPER 70S/NEAR 80F
FROM HXD SOUTH ALONG THE GA COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AT KCHS...MVFR/IFR CEILINGS WILL PREVAIL THROUGH MONDAY. A PERIOD
OF LIFR CEILINGS ARE POSSIBLE LATE TONIGHT INTO MONDAY MORNING. AT
KSAV...VFR CONDITIONS SHOULD GIVE WAY TO MVFR/IFR CEILINGS LATER
TONIGHT...BUT TIMING REMAINS UNCERTAIN. ONCE SUB-VFR CEILINGS
DEVELOP THESE CONDITIONS WILL PREVAIL THROUGH MOST OF MONDAY WITH
ONLY BRIEF IMPROVEMENT TO VFR POSSIBLE MONDAY AFTERNOON. AT BOTH
SITES...00Z TAFS INDICATE VCSH UNTIL LATER TONIGHT. THEN...SHOWERS/
THUNDERSTORMS ARE LIKELY AT BOTH SITES ESPECIALLY MONDAY
AFTERNOON. HOWEVER...DUE TO UNCERTAINTY REGARDING WORST CONDITIONS
OPTED FOR PREVAILING -SHRA AND VCTS/CBS AT BOTH TERMINALS MONDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
OVERNIGHT...A STATIONARY FRONT WILL WAVER SLIGHTLY SOUTH INTO GA
WATERS. NORTH OF THE FRONT...NE WINDS 5-15 KT WILL PREVAIL...WHILE
S/SE WINDS AT SIMILAR SPEEDS WILL PREVAIL SOUTH OF THE FRONT.
CLOSE TO THE FRONT...VARIABLE WINDS WILL REMAIN LESS THAN 10
KT...AND CONDITIONS WILL BE FAVORABLE FOR ISOLATED WATERSPOUTS.
OUTSIDE ANY THUNDERSTORMS...SEAS 1-3 FT WILL PREVAIL OVERNIGHT.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

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

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...
AVIATION...33/SPR
MARINE...33/SPR








000
FXUS62 KCHS 150105
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
905 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT ACROSS THE AREA THIS EVENING WILL WAVER SOUTH
OVERNIGHT. THE FRONT WILL GRADUALLY DISSIPATE MONDAY. A PRE-FRONTAL
TROUGH WILL MOVE IN TUESDAY....THEN A STRONGER COLD FRONT IS FORECAST
TO PUSH THROUGH THE REGION DURING THE MIDDLE OF THE WEEK. A STRONG
INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE
FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
LATE SUNDAY EVENING...CONVECTION REMAINS FOCUSED ALONG COMPLEX
OUTFLOW BOUNDARIES IN THE VICINITY OF A STATIONARY FRONT WHICH
BISECTS THE FORECAST AREA. SLOW/ERRATIC CONVECTION PROPAGATION
WILL CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL...ESPECIALLY FROM
BULLOCH COUNTY EAST TO COASTAL COLLETON COUNTY. MAINTAINED THE
ONGOING FLASH FLOOD WATCH FOR THIS CORRIDOR. PER RECENT/ EXPECTED
RADAR TRENDS...DISCONTINUED THE PORTION OF THE WATCH WHICH
INCLUDED SAVANNAH AND CHARLESTON.

IN THE NEAR TERM...CATEGORICAL/LIKELY POPS REMAIN IN EFFECT CLOSE
TO THE STATIONARY FRONT...TAPERED THROUGH CHANCE TO SLIGHT CHANCE
NORTH AND SOUTH. EXPECT A GRADUAL DIMINISHING TREND IN CONVECTION
COVERAGE/INTENSITY OVERNIGHT...BUT AT LEAST SLIGHT CHANCE/CHANCE
POPS WILL PERSIST MOST AREAS THROUGH MOST/ALL OF THE NIGHT. LOCALLY
GREATER POPS COULD STILL BE REQUIRED OVERNIGHT...ESPECIALLY TOWARD
THE COAST...WILL CONTINUE TO ASSESS.

ALSO OF NOTE...LOWERING STRATUS COULD SUPPORT FOG ALONG/NORTH OF THE
FRONT OVERNIGHT.

LOWS LIKELY TO BE MODULATED BY THE RAIN BUT SHOULD GENERALLY
RANGE FROM THE UPPER 60S NORTH AND WEST TO LOWER TO MID 70S SOUTH
AND EAST...POSSIBLY SOME UPPER 70S ALONG THE GA COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
AT KCHS...MVFR/IFR CEILINGS WILL PREVAIL THROUGH MONDAY. A PERIOD
OF LIFR CEILINGS ARE POSSIBLE LATE TONIGHT INTO MONDAY MORNING. AT
KSAV...VFR CONDITIONS SHOULD GIVE WAY TO MVFR/IFR CEILINGS LATER
TONIGHT...BUT TIMING REMAINS UNCERTAIN. ONCE SUB-VFR CEILINGS
DEVELOP THESE CONDITIONS WILL PREVAIL THROUGH MOST OF MONDAY WITH
ONLY BRIEF IMPROVEMENT TO VFR POSSIBLE MONDAY AFTERNOON. AT BOTH
SITES...00Z TAFS INDICATE VCSH UNTIL LATER TONIGHT. THEN...SHOWERS/
THUNDERSTORMS ARE LIKELY AT BOTH SITES ESPECIALLY MONDAY
AFTERNOON. HOWEVER...DUE TO UNCERTAINTY REGARDING WORST CONDITIONS
OPTED FOR PREVAILING -SHRA AND VCTS/CBS AT BOTH TERMINALS MONDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
TONIGHT...A STATIONARY FRONT WILL WAVER SLIGHTLY BETWEEN SC AND GA WATERS.
NORTH OF THE FRONT...NE WINDS 5-15 KT WILL PREVAIL...WHILE S/SE
WINDS AT SIMILAR SPEEDS WILL PREVAIL SOUTH OF THE FRONT. CLOSE TO
THE FRONT...VARIABLE WINDS WILL REMAIN LESS THAN 10 KT...AND
CONDITIONS WILL BE FAVORABLE FOR ISOLATED WATERSPOUTS. OUTSIDE ANY
THUNDERSTORMS...SEAS 1-3 FT WILL PREVAIL OVERNIGHT.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ099>101-
     114-115.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ047>049-
     051.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...
AVIATION...33/SPR
MARINE...33/SPR








000
FXUS62 KCHS 150105
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
905 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT ACROSS THE AREA THIS EVENING WILL WAVER SOUTH
OVERNIGHT. THE FRONT WILL GRADUALLY DISSIPATE MONDAY. A PRE-FRONTAL
TROUGH WILL MOVE IN TUESDAY....THEN A STRONGER COLD FRONT IS FORECAST
TO PUSH THROUGH THE REGION DURING THE MIDDLE OF THE WEEK. A STRONG
INLAND WEDGE OF HIGH PRESSURE WILL THEN PREVAIL IN WAKE OF THE
FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
LATE SUNDAY EVENING...CONVECTION REMAINS FOCUSED ALONG COMPLEX
OUTFLOW BOUNDARIES IN THE VICINITY OF A STATIONARY FRONT WHICH
BISECTS THE FORECAST AREA. SLOW/ERRATIC CONVECTION PROPAGATION
WILL CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL...ESPECIALLY FROM
BULLOCH COUNTY EAST TO COASTAL COLLETON COUNTY. MAINTAINED THE
ONGOING FLASH FLOOD WATCH FOR THIS CORRIDOR. PER RECENT/ EXPECTED
RADAR TRENDS...DISCONTINUED THE PORTION OF THE WATCH WHICH
INCLUDED SAVANNAH AND CHARLESTON.

IN THE NEAR TERM...CATEGORICAL/LIKELY POPS REMAIN IN EFFECT CLOSE
TO THE STATIONARY FRONT...TAPERED THROUGH CHANCE TO SLIGHT CHANCE
NORTH AND SOUTH. EXPECT A GRADUAL DIMINISHING TREND IN CONVECTION
COVERAGE/INTENSITY OVERNIGHT...BUT AT LEAST SLIGHT CHANCE/CHANCE
POPS WILL PERSIST MOST AREAS THROUGH MOST/ALL OF THE NIGHT. LOCALLY
GREATER POPS COULD STILL BE REQUIRED OVERNIGHT...ESPECIALLY TOWARD
THE COAST...WILL CONTINUE TO ASSESS.

ALSO OF NOTE...LOWERING STRATUS COULD SUPPORT FOG ALONG/NORTH OF THE
FRONT OVERNIGHT.

LOWS LIKELY TO BE MODULATED BY THE RAIN BUT SHOULD GENERALLY
RANGE FROM THE UPPER 60S NORTH AND WEST TO LOWER TO MID 70S SOUTH
AND EAST...POSSIBLY SOME UPPER 70S ALONG THE GA COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
AT KCHS...MVFR/IFR CEILINGS WILL PREVAIL THROUGH MONDAY. A PERIOD
OF LIFR CEILINGS ARE POSSIBLE LATE TONIGHT INTO MONDAY MORNING. AT
KSAV...VFR CONDITIONS SHOULD GIVE WAY TO MVFR/IFR CEILINGS LATER
TONIGHT...BUT TIMING REMAINS UNCERTAIN. ONCE SUB-VFR CEILINGS
DEVELOP THESE CONDITIONS WILL PREVAIL THROUGH MOST OF MONDAY WITH
ONLY BRIEF IMPROVEMENT TO VFR POSSIBLE MONDAY AFTERNOON. AT BOTH
SITES...00Z TAFS INDICATE VCSH UNTIL LATER TONIGHT. THEN...SHOWERS/
THUNDERSTORMS ARE LIKELY AT BOTH SITES ESPECIALLY MONDAY
AFTERNOON. HOWEVER...DUE TO UNCERTAINTY REGARDING WORST CONDITIONS
OPTED FOR PREVAILING -SHRA AND VCTS/CBS AT BOTH TERMINALS MONDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
TONIGHT...A STATIONARY FRONT WILL WAVER SLIGHTLY BETWEEN SC AND GA WATERS.
NORTH OF THE FRONT...NE WINDS 5-15 KT WILL PREVAIL...WHILE S/SE
WINDS AT SIMILAR SPEEDS WILL PREVAIL SOUTH OF THE FRONT. CLOSE TO
THE FRONT...VARIABLE WINDS WILL REMAIN LESS THAN 10 KT...AND
CONDITIONS WILL BE FAVORABLE FOR ISOLATED WATERSPOUTS. OUTSIDE ANY
THUNDERSTORMS...SEAS 1-3 FT WILL PREVAIL OVERNIGHT.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ099>101-
     114-115.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ047>049-
     051.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...
AVIATION...33/SPR
MARINE...33/SPR







000
FXUS62 KCHS 142326
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
726 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT ACROSS THE AREA THIS EVENING WILL SHIFT SOUTH
OVERNIGHT AS A WEAK COLD FRONT. THE COLD FRONT WILL WASH OUT ACROSS
THE AREA MONDAY...WITH A PRE-FRONTAL TROUGH TO MOVE IN DURING
TUESDAY. A STRONGER COLD FRONT IS FORECAST TO PUSH THROUGH THE
REGION DURING THE MIDDLE OF THE WEEK...WITH A STRONG INLAND WEDGE
OF HIGH PRESSURE TO PREVAIL IN WAKE OF THE FRONT INTO NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THIS EVENING...CONVECTION WILL CONTINUE TO FOCUS ON COMPLEX
OUTFLOW BOUNDARIES IN THE VICINITY OF A STATIONARY FRONT WHICH
BISECTS THE FORECAST AREA. SLOW/ERRATIC CONVECTION PROPAGATION
WILL CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL.

LIKELY POPS REMAIN IN EFFECT CLOSE TO THE STATIONARY FRONT...TAPERED
THROUGH CHANCE TO SLIGHT CHANCE NORTH AND SOUTH.

CONVECTION SHOULD CONTINUE TO DEVELOP OVERNIGHT...THUS SLIGHT
CHANCE/CHANCE POPS CONTINUE. LOCALLY GREATER POPS COULD BE
REQUIRED OVERNIGHT...WILL CONTINUE TO ASSESS.

ALSO OF NOTE...LOWERING STRATUS COULD SUPPORT FOG ALONG/NORTH OF THE
FRONT OVERNIGHT.

LOWS LIKELY TO BE MODULATED BY THE RAIN BUT SHOULD GENERALLY
RANGE FROM THE UPPER 60S NORTH AND WEST TO LOWER TO MID 70S SOUTH
AND EAST...POSSIBLY SOME UPPER 70S ALONG THE GA COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AT KCHS...MVFR CEILINGS ARE EXPECTED TO PERSIST THROUGH MONDAY.
A PERIOD OF IFR CEILINGS APPEARS LIKELY LATER TONIGHT INTO MONDAY
MORNING...ALTHOUGH TIMING REMAINS UNCERTAIN. ALSO...BRIEF VFR
CEILINGS ARE POSSIBLE THIS EVENING AND AGAIN MONDAY AFTERNOON.
AT KSAV...VFR CONDITIONS SHOULD GIVE WAY TO MVFR/IFR CEILINGS
LATER TONIGHT...BUT TIMING HERE ALSO REMAINS UNCERTAIN. ONCE SUB-
VFR CEILINGS DEVELOP THESE CONDITIONS WILL PREVAIL THROUGH MOST OF
MONDAY WITH ONLY BRIEF IMPROVEMENT TO VFR POSSIBLE MONDAY
AFTERNOON. AT BOTH SITES...00Z TAFS INDICATE VCSH UNTIL LATER
TONIGHT. THEN...SHOWERS/THUNDERSTORMS ARE LIKELY ESPECIALLY MONDAY
AFTERNOON. HOWEVER...DUE TO UNCERTAINTY REGARDING WORST
CONDITIONS OPTED FOR PREVAILING -SHRA AND VCTS/CBS AT BOTH
TERMINALS MONDAY AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
TONIGHT...A STATIONARY FRONT WILL REMAIN OVER THE SC WATERS. WINDS
WILL REMAIN 15 KT OR LESS WITH SEAS 1-2 FT OUTSIDE THUNDERSTORMS.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

.HYDROLOGY...
FLASH FLOOD WATCH REMAIN IN EFFECT THIS EVENING FOR COUNTIES NEAR
THE STATIONARY FRONT. HOWEVER...THE THREAT FOR EXCESSIVE RAINFALL
REMAINS HIGHLY LOCALIZED.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ099>101-
     114>116-118-137-138.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ047>052.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...
AVIATION...33/SPR
MARINE...33/SPR
HYDROLOGY...







000
FXUS62 KCHS 142326
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
726 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT ACROSS THE AREA THIS EVENING WILL SHIFT SOUTH
OVERNIGHT AS A WEAK COLD FRONT. THE COLD FRONT WILL WASH OUT ACROSS
THE AREA MONDAY...WITH A PRE-FRONTAL TROUGH TO MOVE IN DURING
TUESDAY. A STRONGER COLD FRONT IS FORECAST TO PUSH THROUGH THE
REGION DURING THE MIDDLE OF THE WEEK...WITH A STRONG INLAND WEDGE
OF HIGH PRESSURE TO PREVAIL IN WAKE OF THE FRONT INTO NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THIS EVENING...CONVECTION WILL CONTINUE TO FOCUS ON COMPLEX
OUTFLOW BOUNDARIES IN THE VICINITY OF A STATIONARY FRONT WHICH
BISECTS THE FORECAST AREA. SLOW/ERRATIC CONVECTION PROPAGATION
WILL CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL.

LIKELY POPS REMAIN IN EFFECT CLOSE TO THE STATIONARY FRONT...TAPERED
THROUGH CHANCE TO SLIGHT CHANCE NORTH AND SOUTH.

CONVECTION SHOULD CONTINUE TO DEVELOP OVERNIGHT...THUS SLIGHT
CHANCE/CHANCE POPS CONTINUE. LOCALLY GREATER POPS COULD BE
REQUIRED OVERNIGHT...WILL CONTINUE TO ASSESS.

ALSO OF NOTE...LOWERING STRATUS COULD SUPPORT FOG ALONG/NORTH OF THE
FRONT OVERNIGHT.

LOWS LIKELY TO BE MODULATED BY THE RAIN BUT SHOULD GENERALLY
RANGE FROM THE UPPER 60S NORTH AND WEST TO LOWER TO MID 70S SOUTH
AND EAST...POSSIBLY SOME UPPER 70S ALONG THE GA COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AT KCHS...MVFR CEILINGS ARE EXPECTED TO PERSIST THROUGH MONDAY.
A PERIOD OF IFR CEILINGS APPEARS LIKELY LATER TONIGHT INTO MONDAY
MORNING...ALTHOUGH TIMING REMAINS UNCERTAIN. ALSO...BRIEF VFR
CEILINGS ARE POSSIBLE THIS EVENING AND AGAIN MONDAY AFTERNOON.
AT KSAV...VFR CONDITIONS SHOULD GIVE WAY TO MVFR/IFR CEILINGS
LATER TONIGHT...BUT TIMING HERE ALSO REMAINS UNCERTAIN. ONCE SUB-
VFR CEILINGS DEVELOP THESE CONDITIONS WILL PREVAIL THROUGH MOST OF
MONDAY WITH ONLY BRIEF IMPROVEMENT TO VFR POSSIBLE MONDAY
AFTERNOON. AT BOTH SITES...00Z TAFS INDICATE VCSH UNTIL LATER
TONIGHT. THEN...SHOWERS/THUNDERSTORMS ARE LIKELY ESPECIALLY MONDAY
AFTERNOON. HOWEVER...DUE TO UNCERTAINTY REGARDING WORST
CONDITIONS OPTED FOR PREVAILING -SHRA AND VCTS/CBS AT BOTH
TERMINALS MONDAY AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
TONIGHT...A STATIONARY FRONT WILL REMAIN OVER THE SC WATERS. WINDS
WILL REMAIN 15 KT OR LESS WITH SEAS 1-2 FT OUTSIDE THUNDERSTORMS.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

.HYDROLOGY...
FLASH FLOOD WATCH REMAIN IN EFFECT THIS EVENING FOR COUNTIES NEAR
THE STATIONARY FRONT. HOWEVER...THE THREAT FOR EXCESSIVE RAINFALL
REMAINS HIGHLY LOCALIZED.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ099>101-
     114>116-118-137-138.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ047>052.
MARINE...NONE.

&&

$$

NEAR TERM...SPR
SHORT TERM...33
LONG TERM...
AVIATION...33/SPR
MARINE...33/SPR
HYDROLOGY...








000
FXUS62 KCHS 142208
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
608 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT ACROSS THE AREA THIS EVENING WILL SHIFT SOUTH
OVERNIGHT AS A WEAK COLD FRONT. THE COLD FRONT WILL WASH OUT ACROSS
THE AREA MONDAY...WITH A PRE-FRONTAL TROUGH TO MOVE IN DURING
TUESDAY. A STRONGER COLD FRONT IS FORECAST TO PUSH THROUGH THE
REGION DURING THE MIDDLE OF THE WEEK...WITH A STRONG INLAND WEDGE
OF HIGH PRESSURE TO PREVAIL IN WAKE OF THE FRONT INTO NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THIS EVENING...CONVECTION WILL CONTINUE TO FOCUS ON COMPLEX
OUTFLOW BOUNDARIES IN THE VICINITY OF A STATIONARY FRONT WHICH
BISECTS THE FORECAST AREA. SLOW/ERRATIC CONVECTION PROPAGATION
WILL CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL.

LIKELY POPS REMAIN IN EFFECT CLOSE TO THE STATIONARY FRONT...TAPERED
THROUGH CHANCE TO SLIGHT CHANCE NORTH AND SOUTH.

CONVECTION SHOULD CONTINUE TO DEVELOP OVERNIGHT...THUS SLIGHT
CHANCE/CHANCE POPS CONTINUE. LOCALLY GREATER POPS COULD BE
REQUIRED OVERNIGHT...WILL CONTINUE TO ASSESS.

ALSO OF NOTE...LOWERING STRATUS COULD SUPPORT FOG ALONG/NORTH OF THE
FRONT OVERNIGHT.

LOWS LIKELY TO BE MODULATED BY THE RAIN BUT SHOULD GENERALLY
RANGE FROM THE UPPER 60S NORTH AND WEST TO LOWER TO MID 70S SOUTH
AND EAST...POSSIBLY SOME UPPER 70S ALONG THE GA COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
EXPECT INCREASING CHANCES FOR SH/TSTMS AT THE TERMS INTO THIS
EVENING...ESPECIALLY AT KSAV...AS A STALLED FRONT REMAINS IN THE
VICINITY ALONG WITH UNUSUALLY HIGH MOISTURE VALUES. ANY
CONVECTION WILL BE SLOW- MOVING AND CAPABLE OF VERY HEAVY RAINFALL
SO CONDS COULD GO MUCH LOWER THAN MVFR. MVFR CIGS AT KCHS COULD
LINGER A FEW MORE HOURS BUT SHOULD BECOME VFR THIS EVENING BEFORE
DROPPING BACK TO AT LEAST MVFR AGAIN TONIGHT AS LOW-LEVEL MOISTURE
GETS TRAPPED UNDER THE NIGHTTIME INVERSION. CIGS WILL MAINLY BE
VFR AT KSAV OUTSIDE CONVECTION UNTIL LATE TONIGHT WHEN THEY COULD
DROP TO IFR OR LOWER.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
TONIGHT...A STATIONARY FRONT WILL REMAIN OVER THE SC WATERS. WINDS
WILL REMAIN 15 KT OR LESS WITH SEAS 1-2 FT OUTSIDE THUNDERSTORMS.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

.HYDROLOGY...
FLASH FLOOD WATCH REMAIN IN EFFECT THIS EVENING FOR COUNTIES NEAR
THE STATIONARY FRONT. HOWEVER...THE THREAT FOR EXCESSIVE RAINFALL
REMAINS HIGHLY LOCALIZED.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ099>101-
     114>116-118-137-138.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB/SPR
SHORT TERM...33
LONG TERM...
AVIATION...33/RJB/SPR
MARINE...33/RJB/SPR
HYDROLOGY...








000
FXUS62 KCHS 142208
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
608 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT ACROSS THE AREA THIS EVENING WILL SHIFT SOUTH
OVERNIGHT AS A WEAK COLD FRONT. THE COLD FRONT WILL WASH OUT ACROSS
THE AREA MONDAY...WITH A PRE-FRONTAL TROUGH TO MOVE IN DURING
TUESDAY. A STRONGER COLD FRONT IS FORECAST TO PUSH THROUGH THE
REGION DURING THE MIDDLE OF THE WEEK...WITH A STRONG INLAND WEDGE
OF HIGH PRESSURE TO PREVAIL IN WAKE OF THE FRONT INTO NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THIS EVENING...CONVECTION WILL CONTINUE TO FOCUS ON COMPLEX
OUTFLOW BOUNDARIES IN THE VICINITY OF A STATIONARY FRONT WHICH
BISECTS THE FORECAST AREA. SLOW/ERRATIC CONVECTION PROPAGATION
WILL CONTINUE TO SUPPORT LOCALLY HEAVY RAINFALL.

LIKELY POPS REMAIN IN EFFECT CLOSE TO THE STATIONARY FRONT...TAPERED
THROUGH CHANCE TO SLIGHT CHANCE NORTH AND SOUTH.

CONVECTION SHOULD CONTINUE TO DEVELOP OVERNIGHT...THUS SLIGHT
CHANCE/CHANCE POPS CONTINUE. LOCALLY GREATER POPS COULD BE
REQUIRED OVERNIGHT...WILL CONTINUE TO ASSESS.

ALSO OF NOTE...LOWERING STRATUS COULD SUPPORT FOG ALONG/NORTH OF THE
FRONT OVERNIGHT.

LOWS LIKELY TO BE MODULATED BY THE RAIN BUT SHOULD GENERALLY
RANGE FROM THE UPPER 60S NORTH AND WEST TO LOWER TO MID 70S SOUTH
AND EAST...POSSIBLY SOME UPPER 70S ALONG THE GA COAST.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
EXPECT INCREASING CHANCES FOR SH/TSTMS AT THE TERMS INTO THIS
EVENING...ESPECIALLY AT KSAV...AS A STALLED FRONT REMAINS IN THE
VICINITY ALONG WITH UNUSUALLY HIGH MOISTURE VALUES. ANY
CONVECTION WILL BE SLOW- MOVING AND CAPABLE OF VERY HEAVY RAINFALL
SO CONDS COULD GO MUCH LOWER THAN MVFR. MVFR CIGS AT KCHS COULD
LINGER A FEW MORE HOURS BUT SHOULD BECOME VFR THIS EVENING BEFORE
DROPPING BACK TO AT LEAST MVFR AGAIN TONIGHT AS LOW-LEVEL MOISTURE
GETS TRAPPED UNDER THE NIGHTTIME INVERSION. CIGS WILL MAINLY BE
VFR AT KSAV OUTSIDE CONVECTION UNTIL LATE TONIGHT WHEN THEY COULD
DROP TO IFR OR LOWER.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
TONIGHT...A STATIONARY FRONT WILL REMAIN OVER THE SC WATERS. WINDS
WILL REMAIN 15 KT OR LESS WITH SEAS 1-2 FT OUTSIDE THUNDERSTORMS.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

.HYDROLOGY...
FLASH FLOOD WATCH REMAIN IN EFFECT THIS EVENING FOR COUNTIES NEAR
THE STATIONARY FRONT. HOWEVER...THE THREAT FOR EXCESSIVE RAINFALL
REMAINS HIGHLY LOCALIZED.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ099>101-
     114>116-118-137-138.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB/SPR
SHORT TERM...33
LONG TERM...
AVIATION...33/RJB/SPR
MARINE...33/RJB/SPR
HYDROLOGY...







000
FXUS62 KCHS 141959
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
359 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A STATIONARY FRONT ACROSS THE AREA WILL SHIFT SOUTH TONIGHT AS A
WEAK COLD FRONT. THE COLD FRONT WILL WASH OUT ACROSS THE AREA
MONDAY...WITH A PRE- FRONTAL TROUGH TO MOVE IN DURING TUESDAY. A
STRONGER COLD FRONT IS FORECAST TO PUSH THROUGH THE REGION DURING
THE MIDDLE OF THE WEEK...WITH A STRONG INLAND WEDGE OF HIGH
PRESSURE TO PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE STALLED FRONT STRETCHING FROM NEAR CHARLESTON WESTWARD INTO
CENTRAL GEORGIA WILL SAG SOUTHWARD OVERNIGHT TOWARD SOUTHEAST
GEORGIA. THIS BOUNDARY WILL BE THE MAIN FOCUS FOR SHOWERS AND SOME
THUNDERSTORMS...MAINLY INLAND THROUGH THIS EVENING AND THEN
OFFSHORE LATER TONIGHT WHERE THE BEST INSTABILITY WILL BE.
HOWEVER...ISENTROPIC ASCENT ABOVE THE LOW-LEVEL FRONT COULD KEEP A
FEW SHOWERS GOING INLAND...ESPECIALLY ACROSS THE MIDLANDS. THE
MAIN ISSUE WILL BE THE HEAVY RAIN AND FLOODING POTENTIAL AS DEEP
MOISTURE WILL CONTINUE TO REMAIN IN PLACE ALONG WITH SOME UPPER
JET FORCING. WE DECIDED TO DROP THE FLASH FLOOD WATCH FOR NORTHERN
AND WESTERN PORTIONS OF OUR FORECAST AREA WHERE THE MORE STABLE
AIR MASS IS IN PLACE BUT IT REMAINS IN EFFECT THROUGH THIS EVENING
GENERALLY SOUTH OF A CHARLESTON TO WALTERBORO TO SYLVANIA LINE.
THERE COULD BE SOME FOG LATE...MAINLY INLAND DUE TO THE LOWERING
OF STRATUS. LOWS LIKELY TO BE MODULATED BY THE RAIN BUT SHOULD
GENERALLY RANGE FROM THE UPPER 60S NORTH AND WEST TO LOWER TO MID
70S SOUTH AND EAST...POSSIBLY SOME UPPER 70S ALONG THE GA COAST.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
MONDAY...THE LARGE SCALE PATTERN INDICATES THAT THE MID-LATITUDE
WESTERLIES WILL START TO IMPINGE ON THE FLAT RIDGING ALOFT OVER THE
LOCAL REGION...AS A SHORT WAVE TROUGH DROPS EAST/SE INTO THE GREAT
LAKES AND OHIO VALLEY. SIMULTANEOUSLY AT THE SURFACE THE INITIAL
COLD FRONT BECOMES LESS-DEFINED AND ESSENTIALLY WASHES OUT OVER OR
NEARBY AS THE SEA BREEZE CIRCULATION OVERSPREADS THE AREA AND
PROGRESSES INLAND FROM EAST TO WEST THROUGH THE DAY. MOISTURE IS
STILL PLENTIFUL WITH PWATS BETWEEN 1 AND 2 STANDARD DEVIATIONS ABOVE
NORMAL...PLUS THERE IS MODEST THERMODYNAMICS AND A UPPER JET STREAK
THAT SUGGESTS WE SHOULD EXPERIENCE SCATTERED TO NUMEROUS SHOWERS AND
T-STORMS AREAWIDE. COVERAGE DURING THE MORNING WILL BE GREATEST NEAR
THE REMNANT FRONT AND WHERE THE BEST LOW LEVEL CONVERGENCE IS
OBSERVED FROM CHARLESTON COUNTY TO NEAR THE SAVANNAH AREA. COVERAGE
EXPANDS INLAND DURING THE AFTERNOON AS MESO-SCALE BOUNDARY
INTERACTIONS OCCUR...WITH AT LEAST 50-60 PERCENT PROBABILITIES
INLAND FROM US-17. STORM MOTION IN THE ATMOSPHERE IS STILL
LIMITED...SO LOCALLY HEAVY RAINFALL IS CERTAINLY POSSIBLE. TEMPS
WILL TOP OUT IN THE 85-90 DEGREE RANGE PRIOR TO THE ONSET OF THE
CONVECTIVE RAINS. SCATTERED SHOWERS/TSTMS WILL BE ONGOING DURING THE
EARLY EVENING HOURS GIVEN BOUNDARY MERGERS/INTERACTIONS AND
SUFFICIENT MOISTURE. ACTIVITY WILL GRADUALLY WIND DOWN AS THE NIGHT
PROGRESSES...BUT WE/LL STILL HOLD ONTO SLIGHT CHANCE/CHANCE POPS
EVEN AFTER MIDNIGHT. STRATUS BUILD-DOWN AND CONDENSATION PRESSURE
DEFICITS UNDER 10-20 MB COULD LEAD TO SOME LATE NIGHT FOG CONCERNS.
TEMPS WILL AVERAGE A FEW DEGREES ABOVE NORMAL.

TUESDAY...A BROAD LARGE SCALE TROUGH WILL DOMINANT THE SCENARIO
ALOFT...WHILE A NE-SW ALIGNED SURFACE TROUGH APPROACHES FROM THE
WEST AND NW. EMBEDDED WITHIN THE TROUGH WE FIND A WEAKENING MID
LEVEL IMPULSE THAT ARRIVES LATE IN THE DAY. THE ADDITIONAL FORCING
ASSOCIATED WITH WITH THIS FEATURE PLUS THE RIGHT ENTRANCE REGION TO
THE NEARBY UPPER JET WILL TRIGGER WILL HAVE AMPLE MOISTURE TO WORK
WITH...THUS TRIGGERING SCATTERED TO NUMEROUS POPS. THERMODYNAMICS
ARE MORE FAVORABLE THAN RECENT DAYS...AND WITH A LITTLE MORE FLOW
ALOFT AND SEVERAL MESO-SCALE BOUNDARIES WE ANTICIPATE THAT A FEW OF
THE STORMS COULD BECOME STRONG OR EVEN MARGINALLY SEVERE. HOWEVER
THE RISK FOR ANY ORGANIZED SEVERE WEATHER IS GIVEN LIMITED DEEP
LAYER SHEAR AND ONLY MODEST INSTABILITY AT BEST. SOME COMPRESSIONAL
HEATING ADVANCE OF THE SURFACE TROUGH AND A DEEP DOWNSLOPE FETCH OFF
THE APPALACHIANS WILL BE ENOUGH TO NEGATE CONSIDERABLE CLOUD
COVER...AND SUPPORTS MAX TEMPS IN THE UPPER 80S TO NEAR 90.

WEDNESDAY...THE PRE-FRONTAL TROUGH USHERS IN THE APPROACH OF OUR
NEXT COLD FRONT...WHILE BROAD TROUGHINESS PREVAILS ALOFT. WHILE SOME
DRIER AIR DOES ARRIVE AS HIGH PRESSURE BUILDS SOUTH FROM THE
MID-ATLANTIC STATES AND OHIO VALLEY BY LATE IN THE DAY...THERE IS
STILL ADEQUATE MOISTURE AND FORCING UPSTAIRS FROM THE RIGHT REAR QUAD
OF THE UPPER JET AND ANOTHER SHORT WAVE TO ALLOW FOR CHANCE POPS.
HIGHEST PROBABILITIES WILL BE OVER COASTAL SE GA WHERE THE BEST LOW
LEVEL FORCING WILL OCCUR IN SYNC TO THE PROXIMITY TO SURFACE TROUGH
AND DEEPER MOISTURE PROFILES. THE PUSH OF THE NOTICEABLY COOLER AIR
MASS ISN/T UNTIL WEDNESDAY NIGHT...SO MID AND UPPER 80S WILL PREVAIL
PRIOR TO THEN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
EXPECT INCREASING CHANCES FOR SH/TSTMS AT THE TERMS INTO THIS
EVENING...ESPECIALLY AT KSAV...AS A STALLED FRONT REMAINS IN THE
VICINITY ALONG WITH UNUSUALLY HIGH MOISTURE VALUES. ANY
CONVECTION WILL BE SLOW- MOVING AND CAPABLE OF VERY HEAVY RAINFALL
SO CONDS COULD GO MUCH LOWER THAN MVFR. MVFR CIGS AT KCHS COULD
LINGER A FEW MORE HOURS BUT SHOULD BECOME VFR THIS EVENING BEFORE
DROPPING BACK TO AT LEAST MVFR AGAIN TONIGHT AS LOW-LEVEL MOISTURE
GETS TRAPPED UNDER THE NIGHTTIME INVERSION. CIGS WILL MAINLY BE
VFR AT KSAV OUTSIDE CONVECTION UNTIL LATE TONIGHT WHEN THEY COULD
DROP TO IFR OR LOWER.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE IN
OCCASIONAL SHRA AND/OR TSRA...AND MAINLY DURING THE AFTERNOON AND
EARLY NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS
AND/OR LIGHT FOG THROUGH THE WEEK.

&&

.MARINE...
TONIGHT...A STATIONARY FRONT WILL REMAIN OVER THE SC WATERS. WINDS
WILL REMAIN 10 KT OR LESS WITH SEAS 1-2 FT OUTSIDE THUNDERSTORMS.

MONDAY THROUGH TUESDAY...A WEAK PRESSURE PATTERN WILL EXIST ACROSS
THE MARINE AREA DURING THIS TIME AS THE COLD FRONT BECOMES DIFFUSE
MONDAY AND DISSIPATES...BEFORE A PRE-FRONTAL TROUGH HEADS OUR WAY
TUESDAY. OUTSIDE OF ANY WATERSPOUTS AND ISOLATED TO SCATTERED
CONVECTION WINDS AND SEAS WILL BE NO MORE THAN 10 OR 12 KT AND 2 OR
3 FT...RESPECTIVELY. CONDITIONS APPEAR TO FAVOR POSSIBLE WATERSPOUTS
MONDAY AND TUESDAY MORNINGS...GIVEN A LIGHT WIND REGIME...ADEQUATE
INSTABILITY AND HIGH MOISTURE. WE/LL DEFER TO LATER SHIFTS TO
DETERMINE WHERE TO ISSUE ANY MARINE WEATHER STATEMENTS PENDING WHERE
THE BETTER DEFINED CONVERGENT BOUNDARIES FORM.

WEDNESDAY...A TRANSITION DAY ACROSS THE COASTAL WATERS AS A BACK
DOOR COLD FRONT ARRIVES FROM THE NORTH. THE PRESSURE GRADIENT SLOWLY
TIGHTENS...ESPECIALLY WEDNESDAY NIGHT...SO WINDS AND SEAS WILL
REMAIN WELL BELOW ANY SMALL CRAFT CRITERIA. HOWEVER...SOME LONGER
PERIOD SWELL FROM DISTANT TC EDOUARD WILL BEGIN TO IMPACT THE
COASTAL WATERS MAKING FOR SOME PROBLEMS IN NAVIGATION.

THURSDAY THROUGH SATURDAY...CONDITIONS WILL HAVE DETERIORATED AS A
SOLID NE PINCHING EVENT UNFOLDS BETWEEN THE STALLED FRONT TO OUR
SOUTH AND A STRENGTHENING WEDGE INLAND. THE COMBINATION OF THE
TIGHTER GRADIENT AND A MIX OF LINGERING SWELLS FROM FAR OFF TC
EDOUARD AND THE LONG ONSHORE FETCH SUPPORTS THE POTENTIAL FOR SMALL
CRAFT ADVISORIES.

RIP CURRENTS...LONG PERIOD SWELL FROM TC EDOUARD WILL ARRIVE AT THE
BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE STRONGER ONSHORE
WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH SUNDAY. THESE
CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF RIP CURRENTS
DURING THE SECOND HALF OF THE WEEK. SINCE THIS IS MY FIRST GOOD LOOK
AT THE SITUATION I/LL HOLD OFF ADDING TO THE HAZARDOUS WEATHER
OUTLOOK AT THIS STAGE PENDING MORE CONTINUITY.

&&

.HYDROLOGY...
CONVECTION BEGINNING TO FIRE THIS AFTERNOON ALONG A BACKDOOR COLD
FRONT WHICH HAS STALLED OUT ACROSS THE FORECAST AREA. THIS
BOUNDARY WILL BE THE MAIN FOCUS FOR MORE SHOWERS AND SOME
THUNDERSTORMS THROUGH THIS EVENING WITH THE POTENTIAL FOR SOME
HEAVY RAINFALL AND LOCALIZED FLOODING...MAINLY SOUTH OF A
CHARLESTON TO WALTERBORO TO SYLVANIA LINE. SEVERAL INCHES OF
RAINFALL WILL BE POSSIBLE IN A SHORT AMOUNT OF TIME GIVEN THE VERY
MOIST ATMOSPHERE AND LIGHT WIND FIELDS...ESPECIALLY IN THE
STRONGER CONVECTION.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ099>101-
     114>116-118-137-138.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...33
LONG TERM...
AVIATION...33/RJB
MARINE...33/RJB
HYDROLOGY...








000
FXUS62 KCHS 141722
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
122 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A BACKDOOR COLD FRONT WILL STALL OVER THE AREA TODAY AND LINGER
FOR THE NEXT FEW DAYS. A STRONGER COLD FRONT WILL PUSH THROUGH THE
REGION BY THE MIDDLE OF THE WEEK. STRONG SURFACE HIGH PRESSURE
WILL BUILD FROM THE NORTH IN THE WAKE OF THE FRONT DURING THE LATE
WEEK PERIOD.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES TO THE PREVIOUS FORECAST. THE STALLED FRONT LOOKS
TO BE JUST NORTH AND WEST OF THE AREA WITH THE PRE-FRONTAL WIND
SHIFT LOOKING LIKE IT HAS LOST ITS STEAM NEAR THE SAVANNAH RIVER
GIVEN THE DAYTIME HEATING/LACK OF UPSTREAM PRECIP. SO FAR RAINFALL
HAS BEEN LIMITED THIS MORNING BUT RADAR IS SHOWING SOME SHOWERS
OVER EAST-CENTRAL GEORGIA ALONG AND SOUTH OF THE FRONT/WIND SHIFT.
LATEST HRRR/RUC INDICATE MOST OF THE CONVECTION FIRING NEAR AND
SOUTH OF THIS BOUNDARY...MAINLY SOUTH OF CHARLESTON. THUS... HAVE
LOWERED RAIN CHANCES A BIT TO THE NORTH AND WEST PORTION OF THE
FORECAST AREA...ALTHOUGH MAINTAINED THE FLASH FLOOD WATCH FOR ALL
ZONES FOR NOW AS ANY SHOWERS AND STORMS WILL BE SLOW-MOVING AND
CAPABLE OF PRODUCING VERY HEAVY RAINFALL. WILL CONSIDER DROPPING
THE WATCH FOR NORTHERN AND WESTERN AREAS WITH THE FULL FORECAST
PACKAGE IN A FEW HOURS AS RADAR TRENDS BECOME A BIT CLEARER. WITH
TEMPS STILL IN THE 70S NORTH AND WEST WE LOWERED HIGHS A TAD
THERE TO AROUND 80. ELSEWHERE MID TO UPPER 80S LOOK REASONABLE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING DURING THE
EARLY EVENING HOURS ACROSS MUCH OF THE FORECAST AREA. ACTIVITY WILL
GRADUALLY WIND DOWN AS THE EVENING PROGRESSES...BUT A RISK FOR
RAIN WILL LINGER THROUGH MUCH OF THE NIGHT. HEAVY RAIN AND
FLOODING WILL REMAIN A POSSIBILITY THROUGH LATE EVENING...POSSIBLY
A BIT LATER DEPENDING ON HOW MESOSCALE TRENDS UNFOLD. LIKELY POPS
WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS OVERNIGHT WITH LOWS
RANGING FROM THE LOWER 70S INLAND TO THE MID-UPPER 70S AT THE
COAST.

MONDAY...THE STALLED FRONT WILL LINGER ACROSS THE FORECAST AREA
AND EVENTUALLY BECOME ILL-DEFINED WITHIN AFTERNOON SEABREEZE
CIRCULATION...WHILE THE FLAT UPPER RIDGE REMAINS IN CONTROL OF
THE PATTERN ALOFT FOR ONE MORE DAY. CONVERGENCE ALONG THE
SEABREEZE AND WEAK FRONTAL ZONE...COMBINED WITH DEEP MOISTURE
EVIDENT IN PRECIPITABLE WATER VALUES BETWEEN 2 AND 2.5
INCHES...WILL SUPPORT SCATTERED TO NUMEROUS THUNDERSTORMS PEAKING
IN THE AFTERNOON/EARLY EVENING. WEAK WIND FIELDS IN THE LOW TO
MID LEVELS ONCE AGAIN SUGGEST SLOW STORM MOTIONS AND THE POTENTIAL
FOR THUNDERSTORMS TO PRODUCE HEAVY RAINFALL AND LOCALIZED
FLOODING...ESPECIALLY WHERE STORM MERGERS AND BOUNDARY
INTERACTIONS OCCUR. ALTHOUGH THE BEST THUNDERSTORM COVERAGE WILL
EVENTUALLY SHIFT TO THE MARINE ZONES OVERNIGHT...ISOLATED
SHOWERS/THUNDERSTORMS ARE STILL POSSIBLE ACROSS LAND AREAS AFTER
SUNSET. TEMPERATURES WILL CONTINUE TO RUN ABOVE SEASONAL
NORMALS...PEAKING IN THE MID TO UPPER 80S INLAND DURING THE
AFTERNOON AND FALLING INTO THE LOW 70S AT NIGHT.

TUESDAY...THE UPPER RIDGE ACROSS THE SOUTHERN STATES WILL STEADILY
BE REPLACED BY AN AMPLIFYING TROUGH EXTENDING DOWN THE EAST
COAST. SHORTWAVE ENERGY WILL EFFECTIVELY TRACK INTO THE FORECAST
AREA ALONG THE BASE OF THE TROUGH...ALLOWING A STRONGER COLD FRONT
TO SLIP SOUTHEAST FROM THE APPALACHIAN REGION EARLY IN THE
DAY...MOVING INTO THE FORECAST AREA AND TOWARD THE COASTLINE
THROUGH WEDNESDAY MORNING. RAIN CHANCES WILL AGAIN BE QUITE
HIGH...WITH FORCING FROM THE SURFACE FRONT AND SHORTWAVE ENERGY
SUPPORTING SCATTERED CONVECTION ACROSS THE AREA. ALTHOUGH THE
STRONGEST DYNAMICS WILL REMAIN NORTH OF THE FORECAST AREA DURING
THE TIME OF PEAK INSTABILITY...THE RIGHT ENTRANCE REGION OF AN
UPPER JET WILL DESCEND INTO THE SOUTHEAST STATES AS THE DAY
PROGRESSES. THERE IS THUS A SLIGHT INCREASE IN THE POTENTIAL FOR
ISOLATED STRONG TO EVEN SEVERE THUNDERSTORMS...CONSIDERING THE
LARGER SCALE FORCING FROM THE COLD FRONT AND SHORTWAVE ENERGY.
DESPITE THICK CLOUD COVER AND PERIODS OF SHOWERS/THUNDERSTORMS...A
DOWNSLOPE FLOW AND FRONTAL COMPRESSION WILL SUPPORT UNSEASONABLY
WARM TEMPERATURES IN THE UPPER 80S AWAY FROM THE LOCALLY COOLER
COASTLINE. HOWEVER NIGHTTIME LOW TEMPERATURES WILL REFLECT THE
PASSAGE OF THE FRONT AND SUBSEQUENT NORTHERLY FLOW IN ITS
WAKE...WITH TEMPERATURES FALLING IN THE UPPER 60S TO LOW 70S.

WEDNESDAY...THE FRONT WILL SLOWLY SHIFT OFF THE SOUTHEAST
COAST...WHILE SURFACE HIGH PRESSURE ACROSS THE OHIO VALLEY AND NEW
ENGLAND REGION BUILDS A RIDGE DOWN THE APPALACHIANS AND INTO THE
SOUTHEAST STATES. SOLID NORTHEAST FLOW WILL SET UP ACROSS THE AREA
WITHIN THE BUILDING WEDGE AND BEHIND THE MEANDERING OFFSHORE
FRONT...AND EXPECT A NOTABLE COOLING TREND TO BE EVIDENT IN
AFTERNOON TEMPERATURES WEDNESDAY. HIGHS WILL PEAK IN THE MID 80S
AWAY FROM THE LOCALLY COOLER COASTLINE...A DEGREE OR TWO COOLER
THAN SEASONAL NORMALS. SUFFICIENT MOISTURE WILL REMAIN ACROSS THE
AREA TO SUPPORT SCATTERED SHOWERS/THUNDERSTORMS DURING THE DAYTIME
HOURS...ESPECIALLY AS ADDITIONAL SHORTWAVE ENERGY PASSES ALONG THE
AXIS OF THE UPPER TROUGH ALONG THE EAST COAST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
EXPECT INCREASING CHANCES FOR SH/TSTMS AT THE TERMS INTO THIS
EVENING...ESPECIALLY AT KSAV...AS A STALLED FRONT REMAINS IN THE
VICINITY ALONG WITH UNUSUALLY HIGH MOISTURE VALUES. ANY
CONVECTION WILL BE SLOW- MOVING AND CAPABLE OF VERY HEAVY RAINFALL
SO CONDS COULD GO MUCH LOWER THAN MVFR. MVFR CIGS AT KCHS COULD
LINGER A FEW MORE HOURS BUT SHOULD BECOME VFR THIS EVENING BEFORE
DROPPING BACK TO AT LEAST MVFR AGAIN TONIGHT AS LOW-LEVEL MOISTURE
GETS TRAPPED UNDER THE NIGHTTIME INVERSION. CIGS WILL MAINLY BE
VFR AT KSAV OUTSIDE CONVECTION UNTIL LATE TONIGHT WHEN THEY COULD
DROP TO IFR OR LOWER.

EXTENDED AVIATION OUTLOOK...PERIODIC SHOWERS/THUNDERSTORMS
AND POSSIBLE TEMPORARY FLIGHT RESTRICTIONS ARE EXPECTED THROUGH
EARLY WEEK...AS A COLD FRONT STALLS OVER OR NEAR THE AREA. SOME
EARLY MORNING FOG AND/OR LOW CLOUDS WILL ALSO BE POSSIBLE.

&&

.MARINE...
TODAY...NO MAJOR CONCERNS OUTSIDE OF LOW VSBYS FROM HEAVY RAINS
AND THE POTENTIAL FOR ISOLATED WATERSPOUTS THIS MORNING. WINDS
WILL BE RATHER CHAOTIC TODAY AS A BACKDOOR COLD FRONT STALLS OVER
THE CENTRAL WATERS. WINDS WILL TURN LIGHT EAST TO NORTHEAST BEHIND
THE FRONT BUT REMAIN EAST AND SOUTHEAST SOUTH OF THE FRONT. WINDS
WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1-2 FT.

TONIGHT...SIMILAR CONDITIONS ARE EXPECTED TONIGHT AS THE FRONT
REMAINS STALLED OVER THE CENTRAL WATERS. WINDS WILL REMAIN 10 KT
OR LESS WITH SEAS 1-2 FT. LOCALLY HIGHER WINDS WILL BE POSSIBLE
IN/NEAR TSTMS WITH VSBYS OCCASIONALLY DROPPING TO 1 NM OR LESS.

MONDAY THROUGH THURSDAY...MARINE CONDITIONS WILL REMAIN RATHER
QUIET EARLY IN THE WEEK...AS A FRONT STALLS NEAR THE AREA AND
MAINTAINS A WEAK PRESSURE GRADIENT. THERE WILL CONTINUE TO BE A
RISK FOR WATERSPOUTS DUE TO THE LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE MONDAY AND TUESDAY. THE PATTERN TRANSITIONS BY
WEDNESDAY...AS A STRONG COLD FRONT IS ABLE TO PROGRESS THROUGH THE
MARINE ZONES EARLY IN THE DAY AND HIGH PRESSURE BUILDS STRONGLY
FROM THE NORTH. THE GRADIENT WILL BECOME QUITE TIGHT BETWEEN THE
INLAND HIGH PRESSURE WEDGE AND SURFACE TROUGH/LOW PRESSURE WAVES
OFFSHORE...SUPPORTING A SURGE IN NORTHEAST FLOW BY THURSDAY. SMALL
CRAFT ADVISORIES ARE POSSIBLE LATE WEEK...AS WINDS AND SEAS
INCREASE ACCORDINGLY.

&&

.HYDROLOGY...
TRICKY HYDROLOGIC SITUATION TODAY AS MANY FACTORS POINT TO
WIDESPREAD HEAVY RAINFALL /AS NOTED ABOVE/...ALTHOUGH THE LATEST MODEL
GUIDANCE SUGGESTS HEAVY RAINFALL WILL BE LIMITED AND MAINLY SOUTH
OF CHARLESTON. ANY STRONGER CONVECTION COULD EASILY PRODUCE 2 INCH
OR MORE PER HOUR RAIN RATES AND THUS THERE WILL BE A RISK FOR
FLASH FLOODING...ESPECIALLY IN THE MORE FLOOD-PRONE AREAS LIKE
DOWNTOWN CHARLESTON/SAVANNAH AROUND HIGH TIDE EARLY THIS
AFTERNOON. THE FLASH FLOOD WATCH WILL CONTINUE FOR SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE THIS
EVENING...ALTHOUGH WILL BE CONSIDERING DROPPING THE WATCH FOR
NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA LATER TODAY
BASED ON RADAR TRENDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR GAZ087-088-
     099>101-114>119-137-138.
SC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ040-
     042>045-047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...RJB
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 141441
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1041 AM EDT SUN SEP 14 2014

.SYNOPSIS...
A BACKDOOR COLD FRONT WILL STALL OVER THE AREA TODAY AND LINGER
FOR THE NEXT FEW DAYS. A STRONGER COLD FRONT WILL PUSH THROUGH THE
REGION BY THE MIDDLE OF THE WEEK. STRONG SURFACE HIGH PRESSURE
WILL BUILD FROM THE NORTH IN THE WAKE OF THE FRONT DURING THE LATE
WEEK PERIOD.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME CHANGES WERE MADE TO THE PREVIOUS FORECAST...MAINLY TO LOWER
RAIN CHANCES A BIT BASED ON THE LATEST MODEL GUIDANCE WHICH
SUGGESTS LESS IN THE WAY OF QPF...ESPECIALLY ACROSS NORTHERN AND
WESTERN PORTIONS OF THE FORECAST AREA FROM AROUND CHARLESTON
THROUGH WALTERBORO TO ALLENDALE. THE PRE-FRONTAL WIND SHIFT NEAR
THE SAVANNAH RIVER WILL BE THE PRIMARY FOCUS FOR SHOWERS AND SOME
THUNDERSTORMS TODAY. CONDITIONS ARE FAVORABLE FOR HEAVY
RAINFALL...INCLUDING PWATS NEAR 2.3 INCHES /WELL ABOVE
NORMAL/...WEAK ATMOSPHERIC FLOW AND UPPER JET INDUCED DIVERGENCE.
WILL BE MAINTAINING THE FLASH FLOOD WATCH FOR MOST OF THE AREA FOR
NOW...ALTHOUGH WILL BE CONSIDERING DROPPING IT FOR THOSE
AFOREMENTIONED AREAS TO THE NORTH AND WEST IF CURRENT TRENDS
CONTINUE. HIGHS WERE LOWERED A TAD TO THE NORTH AND WEST...RANGING
FROM AROUND 80/LOWER 80S NEAR THE SANTEE RIVER AND INTO THE
EASTERN MIDLANDS WITH MID TO UPPER 80S SOUTH AND EAST...POSSIBLY
TOUCHING 90 NEAR THE ALTAMAHA RIVER IN GA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING DURING THE
EARLY EVENING HOURS ACROSS MUCH OF THE FORECAST AREA. ACTIVITY WILL
GRADUALLY WIND DOWN AS THE EVENING PROGRESSES...BUT A RISK FOR
RAIN WILL LINGER THROUGH MUCH OF THE NIGHT. HEAVY RAIN AND
FLOODING WILL REMAIN A POSSIBILITY THROUGH LATE EVENING...POSSIBLY
A BIT LATER DEPENDING ON HOW MESOSCALE TRENDS UNFOLD. LIKELY POPS
WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS OVERNIGHT WITH LOWS
RANGING FROM THE LOWER 70S INLAND TO THE MID-UPPER 70S AT THE
COAST.

MONDAY...THE STALLED FRONT WILL LINGER ACROSS THE FORECAST AREA
AND EVENTUALLY BECOME ILL-DEFINED WITHIN AFTERNOON SEABREEZE
CIRCULATION...WHILE THE FLAT UPPER RIDGE REMAINS IN CONTROL OF
THE PATTERN ALOFT FOR ONE MORE DAY. CONVERGENCE ALONG THE
SEABREEZE AND WEAK FRONTAL ZONE...COMBINED WITH DEEP MOISTURE
EVIDENT IN PRECIPITABLE WATER VALUES BETWEEN 2 AND 2.5
INCHES...WILL SUPPORT SCATTERED TO NUMEROUS THUNDERSTORMS PEAKING
IN THE AFTERNOON/EARLY EVENING. WEAK WIND FIELDS IN THE LOW TO
MID LEVELS ONCE AGAIN SUGGEST SLOW STORM MOTIONS AND THE POTENTIAL
FOR THUNDERSTORMS TO PRODUCE HEAVY RAINFALL AND LOCALIZED
FLOODING...ESPECIALLY WHERE STORM MERGERS AND BOUNDARY
INTERACTIONS OCCUR. ALTHOUGH THE BEST THUNDERSTORM COVERAGE WILL
EVENTUALLY SHIFT TO THE MARINE ZONES OVERNIGHT...ISOLATED
SHOWERS/THUNDERSTORMS ARE STILL POSSIBLE ACROSS LAND AREAS AFTER
SUNSET. TEMPERATURES WILL CONTINUE TO RUN ABOVE SEASONAL
NORMALS...PEAKING IN THE MID TO UPPER 80S INLAND DURING THE
AFTERNOON AND FALLING INTO THE LOW 70S AT NIGHT.

TUESDAY...THE UPPER RIDGE ACROSS THE SOUTHERN STATES WILL STEADILY
BE REPLACED BY AN AMPLIFYING TROUGH EXTENDING DOWN THE EAST
COAST. SHORTWAVE ENERGY WILL EFFECTIVELY TRACK INTO THE FORECAST
AREA ALONG THE BASE OF THE TROUGH...ALLOWING A STRONGER COLD FRONT
TO SLIP SOUTHEAST FROM THE APPALACHIAN REGION EARLY IN THE
DAY...MOVING INTO THE FORECAST AREA AND TOWARD THE COASTLINE
THROUGH WEDNESDAY MORNING. RAIN CHANCES WILL AGAIN BE QUITE
HIGH...WITH FORCING FROM THE SURFACE FRONT AND SHORTWAVE ENERGY
SUPPORTING SCATTERED CONVECTION ACROSS THE AREA. ALTHOUGH THE
STRONGEST DYNAMICS WILL REMAIN NORTH OF THE FORECAST AREA DURING
THE TIME OF PEAK INSTABILITY...THE RIGHT ENTRANCE REGION OF AN
UPPER JET WILL DESCEND INTO THE SOUTHEAST STATES AS THE DAY
PROGRESSES. THERE IS THUS A SLIGHT INCREASE IN THE POTENTIAL FOR
ISOLATED STRONG TO EVEN SEVERE THUNDERSTORMS...CONSIDERING THE
LARGER SCALE FORCING FROM THE COLD FRONT AND SHORTWAVE ENERGY.
DESPITE THICK CLOUD COVER AND PERIODS OF SHOWERS/THUNDERSTORMS...A
DOWNSLOPE FLOW AND FRONTAL COMPRESSION WILL SUPPORT UNSEASONABLY
WARM TEMPERATURES IN THE UPPER 80S AWAY FROM THE LOCALLY COOLER
COASTLINE. HOWEVER NIGHTTIME LOW TEMPERATURES WILL REFLECT THE
PASSAGE OF THE FRONT AND SUBSEQUENT NORTHERLY FLOW IN ITS
WAKE...WITH TEMPERATURES FALLING IN THE UPPER 60S TO LOW 70S.

WEDNESDAY...THE FRONT WILL SLOWLY SHIFT OFF THE SOUTHEAST
COAST...WHILE SURFACE HIGH PRESSURE ACROSS THE OHIO VALLEY AND NEW
ENGLAND REGION BUILDS A RIDGE DOWN THE APPALACHIANS AND INTO THE
SOUTHEAST STATES. SOLID NORTHEAST FLOW WILL SET UP ACROSS THE AREA
WITHIN THE BUILDING WEDGE AND BEHIND THE MEANDERING OFFSHORE
FRONT...AND EXPECT A NOTABLE COOLING TREND TO BE EVIDENT IN
AFTERNOON TEMPERATURES WEDNESDAY. HIGHS WILL PEAK IN THE MID 80S
AWAY FROM THE LOCALLY COOLER COASTLINE...A DEGREE OR TWO COOLER
THAN SEASONAL NORMALS. SUFFICIENT MOISTURE WILL REMAIN ACROSS THE
AREA TO SUPPORT SCATTERED SHOWERS/THUNDERSTORMS DURING THE DAYTIME
HOURS...ESPECIALLY AS ADDITIONAL SHORTWAVE ENERGY PASSES ALONG THE
AXIS OF THE UPPER TROUGH ALONG THE EAST COAST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
POTENTIALLY VERY ACTIVE DAY AT THE TERMINALS AS A BACKDOOR COLD
FRONT STALLS OVER THE AREA. BEST CHANCES FOR TSTM IMPACTS WILL BE
FROM 17-20Z AT KCHS AND 19-22Z AT KSAV...ALTHOUGH THESE WINDOWS
MAY NEED TO BE REDEFINED AS THE DAY PROGRESSES. IFR CONDITIONS ARE
CERTAINLY POSSIBLE GIVEN THE HIGH MOISTURE VALUES THAT ARE IN
PLACE...BUT WILL CAP CONDITIONS AT MVFR FOR NOW. INCREASING CHANCE
FOR MVFR CIGS IF NOT IFR CIGS AT KCHS POST FRONT OVERNIGHT.
GUIDANCE NOT CONSISTENT SO WILL CAP AT MVFR FOR NOW. KSAV LOOKS TO
REMAIN SOUTH OF THE FRONT SO VFR THERE.

EXTENDED AVIATION OUTLOOK...PERIODIC SHOWERS/THUNDERSTORMS AND
POSSIBLE TEMPORARY FLIGHT RESTRICTIONS ARE EXPECTED THROUGH EARLY
NEXT WEEK...AS A COLD FRONT STALLS OVER OR NEAR THE AREA. SOME
EARLY MORNING FOG AND/OR LOW CLOUDS WILL ALSO BE POSSIBLE.

&&

.MARINE...
TODAY...NO MAJOR CONCERNS OUTSIDE OF LOW VSBYS FROM HEAVY RAINS
AND THE POTENTIAL FOR ISOLATED WATERSPOUTS THIS MORNING. WINDS
WILL BE RATHER CHAOTIC TODAY AS A BACKDOOR COLD FRONT STALLS OVER
THE CENTRAL WATERS. WINDS WILL TURN LIGHT EAST TO NORTHEAST BEHIND
THE FRONT BUT REMAIN EAST AND SOUTHEAST SOUTH OF THE FRONT. WINDS
WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1-2 FT.

TONIGHT...SIMILAR CONDITIONS ARE EXPECTED TONIGHT AS THE FRONT
REMAINS STALLED OVER THE CENTRAL WATERS. WINDS WILL REMAIN 10 KT
OR LESS WITH SEAS 1-2 FT. LOCALLY HIGHER WINDS WILL BE POSSIBLE
IN/NEAR TSTMS WITH VSBYS OCCASIONALLY DROPPING TO 1 NM OR LESS.

MONDAY THROUGH THURSDAY...MARINE CONDITIONS WILL REMAIN RATHER
QUIET EARLY IN THE WEEK...AS A FRONT STALLS NEAR THE AREA AND
MAINTAINS A WEAK PRESSURE GRADIENT. THERE WILL CONTINUE TO BE A
RISK FOR WATERSPOUTS DUE TO THE LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE MONDAY AND TUESDAY. THE PATTERN TRANSITIONS BY
WEDNESDAY...AS A STRONG COLD FRONT IS ABLE TO PROGRESS THROUGH THE
MARINE ZONES EARLY IN THE DAY AND HIGH PRESSURE BUILDS STRONGLY
FROM THE NORTH. THE GRADIENT WILL BECOME QUITE TIGHT BETWEEN THE
INLAND HIGH PRESSURE WEDGE AND SURFACE TROUGH/LOW PRESSURE WAVES
OFFSHORE...SUPPORTING A SURGE IN NORTHEAST FLOW BY THURSDAY. SMALL
CRAFT ADVISORIES ARE POSSIBLE LATE WEEK...AS WINDS AND SEAS
INCREASE ACCORDINGLY.

&&

.HYDROLOGY...
TRICKY HYDROLOGIC SITUATION TODAY AS MANY FACTORS POINT TO
WIDESPREAD HEAVY RAINFALL /AS NOTED ABOVE/...ALTHOUGH THE LATEST MODEL
GUIDANCE SUGGESTS HEAVY RAINFALL WILL BE LIMITED AND MAINLY SOUTH
OF CHARLESTON. ANY STRONGER CONVECTION COULD EASILY PRODUCE 2 INCH
OR MORE PER HOUR RAIN RATES AND THUS THERE WILL BE A RISK FOR
FLASH FLOODING...ESPECIALLY IN THE MORE FLOOD-PRONE AREAS LIKE
DOWNTOWN CHARLESTON/SAVANNAH AROUND HIGH TIDE EARLY THIS
AFTERNOON. THE FLASH FLOOD WATCH WILL CONTINUE FOR SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE THIS
EVENING...ALTHOUGH WILL BE CONSIDERING DROPPING THE WATCH FOR
NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA LATER TODAY
BASED ON RADAR TRENDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
     114>119-137-138.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
     047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...








000
FXUS62 KCHS 141441
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1041 AM EDT SUN SEP 14 2014

.SYNOPSIS...
A BACKDOOR COLD FRONT WILL STALL OVER THE AREA TODAY AND LINGER
FOR THE NEXT FEW DAYS. A STRONGER COLD FRONT WILL PUSH THROUGH THE
REGION BY THE MIDDLE OF THE WEEK. STRONG SURFACE HIGH PRESSURE
WILL BUILD FROM THE NORTH IN THE WAKE OF THE FRONT DURING THE LATE
WEEK PERIOD.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME CHANGES WERE MADE TO THE PREVIOUS FORECAST...MAINLY TO LOWER
RAIN CHANCES A BIT BASED ON THE LATEST MODEL GUIDANCE WHICH
SUGGESTS LESS IN THE WAY OF QPF...ESPECIALLY ACROSS NORTHERN AND
WESTERN PORTIONS OF THE FORECAST AREA FROM AROUND CHARLESTON
THROUGH WALTERBORO TO ALLENDALE. THE PRE-FRONTAL WIND SHIFT NEAR
THE SAVANNAH RIVER WILL BE THE PRIMARY FOCUS FOR SHOWERS AND SOME
THUNDERSTORMS TODAY. CONDITIONS ARE FAVORABLE FOR HEAVY
RAINFALL...INCLUDING PWATS NEAR 2.3 INCHES /WELL ABOVE
NORMAL/...WEAK ATMOSPHERIC FLOW AND UPPER JET INDUCED DIVERGENCE.
WILL BE MAINTAINING THE FLASH FLOOD WATCH FOR MOST OF THE AREA FOR
NOW...ALTHOUGH WILL BE CONSIDERING DROPPING IT FOR THOSE
AFOREMENTIONED AREAS TO THE NORTH AND WEST IF CURRENT TRENDS
CONTINUE. HIGHS WERE LOWERED A TAD TO THE NORTH AND WEST...RANGING
FROM AROUND 80/LOWER 80S NEAR THE SANTEE RIVER AND INTO THE
EASTERN MIDLANDS WITH MID TO UPPER 80S SOUTH AND EAST...POSSIBLY
TOUCHING 90 NEAR THE ALTAMAHA RIVER IN GA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING DURING THE
EARLY EVENING HOURS ACROSS MUCH OF THE FORECAST AREA. ACTIVITY WILL
GRADUALLY WIND DOWN AS THE EVENING PROGRESSES...BUT A RISK FOR
RAIN WILL LINGER THROUGH MUCH OF THE NIGHT. HEAVY RAIN AND
FLOODING WILL REMAIN A POSSIBILITY THROUGH LATE EVENING...POSSIBLY
A BIT LATER DEPENDING ON HOW MESOSCALE TRENDS UNFOLD. LIKELY POPS
WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS OVERNIGHT WITH LOWS
RANGING FROM THE LOWER 70S INLAND TO THE MID-UPPER 70S AT THE
COAST.

MONDAY...THE STALLED FRONT WILL LINGER ACROSS THE FORECAST AREA
AND EVENTUALLY BECOME ILL-DEFINED WITHIN AFTERNOON SEABREEZE
CIRCULATION...WHILE THE FLAT UPPER RIDGE REMAINS IN CONTROL OF
THE PATTERN ALOFT FOR ONE MORE DAY. CONVERGENCE ALONG THE
SEABREEZE AND WEAK FRONTAL ZONE...COMBINED WITH DEEP MOISTURE
EVIDENT IN PRECIPITABLE WATER VALUES BETWEEN 2 AND 2.5
INCHES...WILL SUPPORT SCATTERED TO NUMEROUS THUNDERSTORMS PEAKING
IN THE AFTERNOON/EARLY EVENING. WEAK WIND FIELDS IN THE LOW TO
MID LEVELS ONCE AGAIN SUGGEST SLOW STORM MOTIONS AND THE POTENTIAL
FOR THUNDERSTORMS TO PRODUCE HEAVY RAINFALL AND LOCALIZED
FLOODING...ESPECIALLY WHERE STORM MERGERS AND BOUNDARY
INTERACTIONS OCCUR. ALTHOUGH THE BEST THUNDERSTORM COVERAGE WILL
EVENTUALLY SHIFT TO THE MARINE ZONES OVERNIGHT...ISOLATED
SHOWERS/THUNDERSTORMS ARE STILL POSSIBLE ACROSS LAND AREAS AFTER
SUNSET. TEMPERATURES WILL CONTINUE TO RUN ABOVE SEASONAL
NORMALS...PEAKING IN THE MID TO UPPER 80S INLAND DURING THE
AFTERNOON AND FALLING INTO THE LOW 70S AT NIGHT.

TUESDAY...THE UPPER RIDGE ACROSS THE SOUTHERN STATES WILL STEADILY
BE REPLACED BY AN AMPLIFYING TROUGH EXTENDING DOWN THE EAST
COAST. SHORTWAVE ENERGY WILL EFFECTIVELY TRACK INTO THE FORECAST
AREA ALONG THE BASE OF THE TROUGH...ALLOWING A STRONGER COLD FRONT
TO SLIP SOUTHEAST FROM THE APPALACHIAN REGION EARLY IN THE
DAY...MOVING INTO THE FORECAST AREA AND TOWARD THE COASTLINE
THROUGH WEDNESDAY MORNING. RAIN CHANCES WILL AGAIN BE QUITE
HIGH...WITH FORCING FROM THE SURFACE FRONT AND SHORTWAVE ENERGY
SUPPORTING SCATTERED CONVECTION ACROSS THE AREA. ALTHOUGH THE
STRONGEST DYNAMICS WILL REMAIN NORTH OF THE FORECAST AREA DURING
THE TIME OF PEAK INSTABILITY...THE RIGHT ENTRANCE REGION OF AN
UPPER JET WILL DESCEND INTO THE SOUTHEAST STATES AS THE DAY
PROGRESSES. THERE IS THUS A SLIGHT INCREASE IN THE POTENTIAL FOR
ISOLATED STRONG TO EVEN SEVERE THUNDERSTORMS...CONSIDERING THE
LARGER SCALE FORCING FROM THE COLD FRONT AND SHORTWAVE ENERGY.
DESPITE THICK CLOUD COVER AND PERIODS OF SHOWERS/THUNDERSTORMS...A
DOWNSLOPE FLOW AND FRONTAL COMPRESSION WILL SUPPORT UNSEASONABLY
WARM TEMPERATURES IN THE UPPER 80S AWAY FROM THE LOCALLY COOLER
COASTLINE. HOWEVER NIGHTTIME LOW TEMPERATURES WILL REFLECT THE
PASSAGE OF THE FRONT AND SUBSEQUENT NORTHERLY FLOW IN ITS
WAKE...WITH TEMPERATURES FALLING IN THE UPPER 60S TO LOW 70S.

WEDNESDAY...THE FRONT WILL SLOWLY SHIFT OFF THE SOUTHEAST
COAST...WHILE SURFACE HIGH PRESSURE ACROSS THE OHIO VALLEY AND NEW
ENGLAND REGION BUILDS A RIDGE DOWN THE APPALACHIANS AND INTO THE
SOUTHEAST STATES. SOLID NORTHEAST FLOW WILL SET UP ACROSS THE AREA
WITHIN THE BUILDING WEDGE AND BEHIND THE MEANDERING OFFSHORE
FRONT...AND EXPECT A NOTABLE COOLING TREND TO BE EVIDENT IN
AFTERNOON TEMPERATURES WEDNESDAY. HIGHS WILL PEAK IN THE MID 80S
AWAY FROM THE LOCALLY COOLER COASTLINE...A DEGREE OR TWO COOLER
THAN SEASONAL NORMALS. SUFFICIENT MOISTURE WILL REMAIN ACROSS THE
AREA TO SUPPORT SCATTERED SHOWERS/THUNDERSTORMS DURING THE DAYTIME
HOURS...ESPECIALLY AS ADDITIONAL SHORTWAVE ENERGY PASSES ALONG THE
AXIS OF THE UPPER TROUGH ALONG THE EAST COAST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A STRONG WEDGE OF SURFACE HIGH PRESSURE WILL PREVAIL INLAND FOR
MUCH OF THE EXTENDED PERIOD...WHILE WAVES OF LOW PRESSURE DEVELOP
ALONG A LINGERING FRONT OFFSHORE THROUGH LATE WEEK. THE AXIS OF
THE UPPER TROUGH WILL REMAIN ALONG THE EAST COAST THROUGH
FRIDAY...THEN WEAKEN AND BECOME MUDDLED OVER THE WEEKEND. THE
BEST RAIN CHANCES WILL LIKELY BECOME INCREASINGLY CONFINED TO THE
IMMEDIATE COASTLINE AND MARINE ZONES WITHIN THIS PATTERN...AS
DEEPER MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE FRONTAL ZONE
AND ASSOCIATED WAVES OF LOW PRESSURE. SOLID NORTHEAST FLOW...AS
WELL AS LOWER HEIGHTS ALOFT...WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S EACH AFTERNOON...WHILE LOW TEMPERATURES FALL INTO THE
LOW TO MID 60S AT LEAST THROUGH FRIDAY NIGHT...BEFORE POSSIBLY
MODERATING A FEW DEGREES SATURDAY AND SUNDAY NIGHTS.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
POTENTIALLY VERY ACTIVE DAY AT THE TERMINALS AS A BACKDOOR COLD
FRONT STALLS OVER THE AREA. BEST CHANCES FOR TSTM IMPACTS WILL BE
FROM 17-20Z AT KCHS AND 19-22Z AT KSAV...ALTHOUGH THESE WINDOWS
MAY NEED TO BE REDEFINED AS THE DAY PROGRESSES. IFR CONDITIONS ARE
CERTAINLY POSSIBLE GIVEN THE HIGH MOISTURE VALUES THAT ARE IN
PLACE...BUT WILL CAP CONDITIONS AT MVFR FOR NOW. INCREASING CHANCE
FOR MVFR CIGS IF NOT IFR CIGS AT KCHS POST FRONT OVERNIGHT.
GUIDANCE NOT CONSISTENT SO WILL CAP AT MVFR FOR NOW. KSAV LOOKS TO
REMAIN SOUTH OF THE FRONT SO VFR THERE.

EXTENDED AVIATION OUTLOOK...PERIODIC SHOWERS/THUNDERSTORMS AND
POSSIBLE TEMPORARY FLIGHT RESTRICTIONS ARE EXPECTED THROUGH EARLY
NEXT WEEK...AS A COLD FRONT STALLS OVER OR NEAR THE AREA. SOME
EARLY MORNING FOG AND/OR LOW CLOUDS WILL ALSO BE POSSIBLE.

&&

.MARINE...
TODAY...NO MAJOR CONCERNS OUTSIDE OF LOW VSBYS FROM HEAVY RAINS
AND THE POTENTIAL FOR ISOLATED WATERSPOUTS THIS MORNING. WINDS
WILL BE RATHER CHAOTIC TODAY AS A BACKDOOR COLD FRONT STALLS OVER
THE CENTRAL WATERS. WINDS WILL TURN LIGHT EAST TO NORTHEAST BEHIND
THE FRONT BUT REMAIN EAST AND SOUTHEAST SOUTH OF THE FRONT. WINDS
WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1-2 FT.

TONIGHT...SIMILAR CONDITIONS ARE EXPECTED TONIGHT AS THE FRONT
REMAINS STALLED OVER THE CENTRAL WATERS. WINDS WILL REMAIN 10 KT
OR LESS WITH SEAS 1-2 FT. LOCALLY HIGHER WINDS WILL BE POSSIBLE
IN/NEAR TSTMS WITH VSBYS OCCASIONALLY DROPPING TO 1 NM OR LESS.

MONDAY THROUGH THURSDAY...MARINE CONDITIONS WILL REMAIN RATHER
QUIET EARLY IN THE WEEK...AS A FRONT STALLS NEAR THE AREA AND
MAINTAINS A WEAK PRESSURE GRADIENT. THERE WILL CONTINUE TO BE A
RISK FOR WATERSPOUTS DUE TO THE LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE MONDAY AND TUESDAY. THE PATTERN TRANSITIONS BY
WEDNESDAY...AS A STRONG COLD FRONT IS ABLE TO PROGRESS THROUGH THE
MARINE ZONES EARLY IN THE DAY AND HIGH PRESSURE BUILDS STRONGLY
FROM THE NORTH. THE GRADIENT WILL BECOME QUITE TIGHT BETWEEN THE
INLAND HIGH PRESSURE WEDGE AND SURFACE TROUGH/LOW PRESSURE WAVES
OFFSHORE...SUPPORTING A SURGE IN NORTHEAST FLOW BY THURSDAY. SMALL
CRAFT ADVISORIES ARE POSSIBLE LATE WEEK...AS WINDS AND SEAS
INCREASE ACCORDINGLY.

&&

.HYDROLOGY...
TRICKY HYDROLOGIC SITUATION TODAY AS MANY FACTORS POINT TO
WIDESPREAD HEAVY RAINFALL /AS NOTED ABOVE/...ALTHOUGH THE LATEST MODEL
GUIDANCE SUGGESTS HEAVY RAINFALL WILL BE LIMITED AND MAINLY SOUTH
OF CHARLESTON. ANY STRONGER CONVECTION COULD EASILY PRODUCE 2 INCH
OR MORE PER HOUR RAIN RATES AND THUS THERE WILL BE A RISK FOR
FLASH FLOODING...ESPECIALLY IN THE MORE FLOOD-PRONE AREAS LIKE
DOWNTOWN CHARLESTON/SAVANNAH AROUND HIGH TIDE EARLY THIS
AFTERNOON. THE FLASH FLOOD WATCH WILL CONTINUE FOR SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE THIS
EVENING...ALTHOUGH WILL BE CONSIDERING DROPPING THE WATCH FOR
NORTHERN AND WESTERN PORTIONS OF THE FORECAST AREA LATER TODAY
BASED ON RADAR TRENDS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
     114>119-137-138.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
     047>052.
MARINE...NONE.

&&

$$

NEAR TERM...RJB
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...







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