[top]
000
FXUS62 KCAE 240329
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1129 PM EDT THU MAY 23 2013
.SYNOPSIS...
FURTHER DRYING WILL OCCUR BEHIND THE COLD FRONT TONIGHT. THE
PRESSURE RIDGE BEHIND THE FRONT WILL EXTEND THROUGH THE
MISSISSIPPI RIVER VALLEY FRIDAY. THE RIDGE WILL MOVE EASTWARD
AND BE ALONG THE EAST COAST SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE COLD FRONT WILL MOVE THROUGH THE FORECAST AREA OVERNIGHT.
LITTLE MOISTURE IS ASSOCIATED WITH THE FRONT. FURTHER DRYING
WILL OCCUR BEHIND THE FRONT BY MORNING. THE TEMPERATURE FORECAST
APPEARS ON TRACK WITH LOWS IN THE UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /6 AM FRIDAY THROUGH SATURDAY NIGHT/...
THE DRY PRESSURE RIDGE APPROACHING FROM THE WEST WILL DOMINATE
THROUGH SATURDAY NIGHT. BELOW NORMAL TEMPERATURES WILL BE
ASSOCIATED WITH THIS AIR MASS. EXPECT LOWS IN THE 40S FRIDAY
NIGHT. SATURDAY NIGHT SHOULD NOT BE QUITE AS COOL BECAUSE OF AIR
MASS MODIFICATION.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT WITH UPPER RIDGE WORKING
IN FROM THE WEST. BOTH MODELS SHOW A WEAK SURFACE FRONTAL BOUNDARY
WHICH REMAINS MAINLY TO THE NORTH BUT ECMWF SHOWS THE FRONT A
LITTLE BIT STRONGER THAN THE GFS. THE ECMWF ALSO KEEPS THE FRONT
A LITTLE FARTHER TO THE SOUTH. DRY TO START SUNDAY AND MONDAY BUT
BY THE END OF THE PERIOD...MOISTURE AND INSTABILITY INCREASES.
EXPECT MORE DIURNAL SHOWERS AND THUNDERSTORMS TUESDAY THROUGH
WEDNESDAY.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE 24 HOUR TAF PERIOD.
SURFACE AND/OR BOUNDARY LAYER WINDS ARE EXPECTED TO STAY UP SOME
LATE TONIGHT...PLUS SOME DRIER AIR WILL FILTER IN BEHIND A WEAK
SURFACE TROUGH...THUS PRECLUDING ANY FOG/STRATUS THREAT. BREEZY
CONDITIONS EXPECTED FRIDAY...BEHIND A DRY COLD FRONT THAT WILL COME
THROUGH IN THE MORNING.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY FRIDAY AFTERNOON IS EXPECTED TO BE IN THE 20 TO
25 PERCENT RANGE. WINDS APPEAR MARGINAL FOR A RED FLAG WARNING...EXPECT
SUSTAINED WINDS MAINLY BELOW 20 MPH. WIND GUSTS EXPECTED TO AROUND
25 MPH. FUEL MOISTURE IS HIGH REDUCING THE FIRE THREAT.
&&
.CLIMATE...
MUCH BELOW NORMAL TEMPERATURES FRIDAY NIGHT/SATURDAY MORNING WITH
LOWS IN THE 40S.
COLUMBIA METRO AIRPORT RECORD LOW MAY 25TH...45 SET IN 1967
AUGUSTA BUSH FIELD RECORD LOW MAY 25TH.......43 SET IN 1951
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
[top]
000
FXUS62 KCHS 240220
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1020 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATE TONIGHT...WITH DRY
HIGH PRESSURE BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
DEEP LAYER TROUGHING AND ASSOCIATED/LOCALIZED LOW LEVEL CONVERGENCE
COULD SUPPORT ANOTHER SHOWER/THUNDERSTORM OR TWO ACROSS NORTHERN
COUNTIES AND ADJACENT COASTAL WATERS FOR A FEW MORE HOURS.
HOWEVER...IN GENERAL DRIER AIR WILL GRADUALLY FILTER INTO THE
REGION OVERNIGHT...ACCOMPANIED BY CLEAR/PARTLY CLOUDY SKIES.
PATCHY FOG COULD DEVELOP ACROSS INLAND/NORTHERN COUNTIES DUE TO
EARLIER RAINFALL AND LIGHT WINDS.
OTHERWISE...MOST FORECAST PARAMETERS REMAIN IN DECENT SHAPE AND
REQUIRED ONLY MINOR/HOURLY AMENDMENTS OVERNIGHT. LOW TEMPERATURES
BY DAYBREAK WILL AVERAGE IN THE MID 60S AT MANY LOCATIONS...EXCEPT
IN THE LOWER 60S AT A FEW OF THE COOLEST INLAND SPOTS AND IN THE
LOWER 70S ON SOME BEACHES.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
THE WEATHER WILL BE RELATIVELY QUIET DURING THIS PERIOD AS HIGH
PRESSURE BUILDS IN FROM THE NORTH ON FRIDAY...SETTLING OVER THE AREA
FOR THE WEEKEND. FRIDAY WILL BE THE WARMEST OF THE THREE DAYS AS
NORTHWESTERLY DOWNSLOPE FLOW WILL ALLOW FOR A LITTLE COMPRESSIONAL
HEATING AT LOW LEVELS. AFTERNOON MAX TEMPS WILL MANAGE TO GET TO
NEAR NORMAL UNDER MOSTLY SUNNY SKIES. THE WINDS MAY GET A BIT BREEZY
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS WITH GOOD MIXING
IN THE BOUNDARY LAYER ALLOWING SOMEWHAT STRONGER WINDS TO MIX TO THE
SURFACE.
FRIDAY NIGHT...STRONG COOL ADVECTION SETTLES IN...WITH TEMPERATURES
DROPPING ALL NIGHT. RISING HEIGHTS ALOFT WILL HELP PROMOTE LOW LEVEL
SUBSIDENCE...KEEPING SKIES CLEAR. TEMPS WILL DROP INTO THE UPPER 40S
TO NEAR 50 WEST OF INTERSTATE 95...WITH LOWER 50S ELSEWHERE. A
PERSISTENT 5 TO 10 KNOT WIND WILL KEEP TEMPS FROM DROPPING EVEN
LOWER.
SATURDAY WILL BE COOL AND SUNNY AS A BUBBLE AREA OF HIGH PRESSURE
SETS UP IN THE NEIGHBORHOOD. DEW POINTS WILL DROP INTO THE 30S BY
AFTERNOON AWAY FROM THE COAST...WHICH IS VERY LOW FOR MEMORIAL DAY
WEEKEND. RELATIVE HUMIDITY VALUES BY THEMSELVES WOULD BE LOW
ENOUGH FOR FIRE WEATHER CONCERNS...BUT THE WINDS WILL BE GENERALLY
LESS THAN 10 KNOTS.
NOT MUCH CHANGE EXPECTED ON SUNDAY WITH THE HIGH REMAINING CLOSE BY.
A WEAK LEE TROF MAY DEVELOP BY AFTERNOON IN THE MIDLANDS...ALLOWING
FOR A BIT MORE ROBUST SEA BREEZE TO FORM...BUT THE LACK OF LOW LEVEL
MOISTURE WILL PREVENT ANY CONVECTIVE ACTIVITY. THERE COULD BE A
LITTLE MORE IN THE WAY OF CIRRUS AS A WEAK DISTURBANCE ALOFT ROTATES
AROUND THE DEEP UPPER LOW EXPECTED OVER NEW ENGLAND...BUT IT WONT
SIGNIFICANTLY DENT THE AMOUNT OF SUNSHINE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE REGION WILL BE SANDWICHED BETWEEN TWO AREAS OF HIGH PRESSURE
EARLY IN THE WEEK...THE STRONGER OF THE TWO PASSING ACROSS THE
MID-ATLANTIC REGION AND THE OTHER OVER THE NORTHEAST GULF OF
MEXICO. DEEPENING MOISTURE WILL RESULT IN AT LEAST AN INCREASE IN
CLOUD COVER...BUT IT APPEARS THE RAIN-FREE CONDITIONS SHOULD
PERSIST THROUGH MEMORIAL DAY. ATLANTIC HIGH PRESSURE WILL THEN
BECOME ESTABLISHED THROUGH THE MIDDLE OF NEXT WEEK...SUPPORTING
MAINLY DIURNAL ISOLATED CONVECTION EACH AFTERNOON ALONG AND AHEAD
OF THE SEA BREEZE TUESDAY THROUGH THURSDAY. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BY EARLY NEXT WEEK AND CONTINUE NEAR
SEASONAL NORMS THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH FRIDAY.
EXTENDED AVIATION...VFR CONDITIONS THROUGH THE WEEKEND.
&&
.MARINE...
WINDS WILL CONTINUE TO VEER TOWARD THE WEST AND WILL INCREASE IN
SPEED OVERNIGHT. WINDS AS HIGH AS 15-20 KT COULD DEVELOP ACROSS
WATERS BEYOND 20 NM LATE. SEAS WILL RANGE FROM 2-4FT WITHIN
NEARSHORE WATERS TO 3-5 FT BEYOND 20 NM. OFFSHORE WINDS WILL
CONTINUE FRIDAY...WITH WINDS VEERING TOWARD THE NORTHWEST
ESPECIALLY IN THE AFTERNOON.
THE MAIN PERIOD OF CONCERN WILL BE FRIDAY NIGHT BEHIND THE COLD
FRONT AS WINDS ACCELERATE FROM THE NORTH AND EVENTUALLY NORTH
NORTHEAST. WINDS AND SEAS WILL BE RIGHT AROUND SCA CRITERIA
OFFSHORE...BUT TOO MARGINAL TO ISSUE ANY HEADLINES AT THIS TIME.
WINDS AND SEAS WILL QUICKLY COME BACK DOWN SATURDAY AS THE
PRESSURE GRADIENT COLLAPSES WHILE HIGH PRESSURES SETTLES OVER THE
WATERS.
WINDS WILL BECOME DIURNALLY DRIVEN NEXT WEEK AS THE SURFACE
HIGH MOVES INTO THE ATLANTIC WITH A WEAK RIDGE STRETCHING WESTWARD
OVER THE CWA. SPEEDS SHOULD BE 15 KNOTS OR LESS THE FIRST HALF OF
NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENINGS. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE AS
ASTRONOMICAL FACTORS WILL CAUSE HIGHER THAN TYPICAL TIDES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...SPR
MARINE...FWA/SPR
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 240213
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1013 PM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
COLD FRONT IN THE UPSTATE AT 02Z WILL MOVE ACROSS THE REGION
OVERNIGHT. DRIER AIR ADVECTING INTO THE AREA...SHOWERS WILL REMAIN
NORTH OF THE REGION...SO REMOVED POPS FOR REST OF NIGHT WITH
CLEARING SKIES. TEMPERATURES FALLING INTO THE UPPER 50S TO LOWER
60S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
DRYING BEHIND THE FRONT SHOULD DOMINATE FRIDAY THROUGH FRIDAY
NIGHT. MIXING ASSOCIATED WITH THE FRONT SUPPORTED THE WARMER
TEMPERATURE GUIDANCE TONIGHT. HIGH PRESSURE WILL BRING COOLER
DRIER CONDITIONS FRIDAY NIGHT AND SATURDAY. WILL GO WITH GFS MOS
GUIDANCE IN THE MID 40S FRIDAY NIGHT AND MODEL BLEND UPPER 70S
TO LOWER 80S SATURDAY. AIR MASS MODIFIES BY SATURDAY NIGHT WITH
LOWS IN THE LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT WITH UPPER RIDGE WORKING
IN FROM THE WEST. BOTH MODELS SHOW A WEAK SURFACE FRONTAL BOUNDARY
WHICH REMAINS MAINLY TO THE NORTH BUT ECMWF SHOWS THE FRONT A
LITTLE BIT STRONGER THAN THE GFS. THE ECMWF ALSO KEEPS THE FRONT
A LITTLE FARTHER TO THE SOUTH. DRY TO START SUNDAY AND MONDAY BUT
BY THE END OF THE EXTENDED PERIOD...THE AIR MASS MOISTURE INCREASES
AND THE INSTABILITY INCREASES. EXPECT MORE DIURNAL SHOWERS AND
THUNDERSTORMS TUESDAY THROUGH WEDNESDAY. HIGH TEMPERATURES
INCREASE FROM THE LOWER 80S SUNDAY TO THE MID 80S MONDAY AND
TUESDAY TO THE UPPER 80S BY WEDNESDAY. OVERNIGHT LOW TEMPERATURES
ARE EXPECTED TO BE IN THE UPPER 50S SUNDAY NIGHT BUT INCREASE TO
THE LOWER 60S FOR THE REST OF THE PERIOD.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE 24 HOUR TAF PERIOD.
SURFACE AND/OR BOUNDARY LAYER WINDS ARE EXPECTED TO STAY UP SOME
TONIGHT...PLUS SOME DRIER AIR WILL FILTER IN BEHIND A WEAK SURFACE
TROUGH...THUS PRECLUDING ANY FOG/STRATUS THREAT. BREEZY CONDITIONS
EXPECTED FRIDAY...BEHIND A DRY COLD FRONT THAT WILL COME THROUGH IN
THE MORNING.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY FRIDAY AFTERNOON IS EXPECTED TO BE IN THE 20 TO
25 PERCENT RANGE. WINDS APPEAR MARGINAL RED FLAG...EXPECT
SUSTAINED WINDS MAINLY BELOW 20 MPH. WIND GUSTS EXPECTED TO AROUND
25 MPH. FUEL MOISTURE IS HIGH REDUCING FIRE THREAT.
&&
.CLIMATE...
MUCH BELOW NORMAL TEMPERATURES FRIDAY NIGHT/SATURDAY MORNING WITH
LOWS IN THE 40S.
COLUMBIA METRO AIRPORT RECORD LOW MAY 25TH...45 SET IN 1967
AUGUSTA BUSH FIELD RECORD LOW MAY 25TH.......43 SET IN 1951
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
[top]
000
FXUS62 KFFC 232351
AFDFFC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
650 PM EDT THU MAY 23 2013
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
UPPER LEVEL TROUGH AND ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH
THE OHIO VALLEY THIS AFTERNOON. ALTHOUGH A DRIER AIR MASS
ACCOMPANIES THE FRONT AND WILL CONTINUE TO MOVE INTO THE
STATE...MOISTURE ASSOCIATED WITH THE TROUGH WILL RETURN TO FAR NORTH
GEORGIA THROUGH THIS EVENING...AND HAVE CONTINUED MENTION OF SLIGHT
CHANCE SHOWERS AND THUNDERSTORMS ACROSS THAT AREA. DIMINISH ANY
REMAINING POPS QUICKLY AFTER 03Z.
MAIN CONCERN THROUGH THE SHORT TERM WILL BE THE TIGHT PRESSURE
GRADIENT ACROSS THE AREA...AND THE ASSOCIATED GUSTY WINDS. AS OF
NOW...MODELS CONSISTENT WITH KEEPING WINDS BELOW WIND ADVISORY
CRITERIA...AND HAVE HELD OFF ON ISSUING ANYTHING AT THIS TIME. IN
GENERAL...EXPECTING NORTHWEST WINDS OF 10 UP TO 20 MPH WITH GUSTS TO
30 MPH. OVERNIGHT SHIFT WILL NEED TO RE-EVALUATE.
TEMPERATURES WILL BE AT OR SLIGHTLY BELOW NORMAL THROUGH THE
WEEKEND. HAVE GENERALLY GONE WITH A MODEL BLEND FOR TEMPERATURES AND
DEWPOINTS.
31
.LONG TERM /SATURDAY THROUGH THURSDAY/...
NO MAJOR CHANGES MADE TO THE CURRENT EXTENDED FORECAST. DRY
WEATHER IS EXPECTED TO CONTINUE ACROSS THE AREA THROUGH SUNDAY AND
FOR THE MOST PART BASED ON THE GFS...THROUGH THURSDAY. HOWEVER THE
EUROPEAN MODEL IS INDICATING A WETTER NW FLOW ALOFT ACROSS N AND
PARTS OF CENTRAL GA STARTING SUNDAY NIGHT WITH A WEAKER UPPER
RIDGE AND GREATER POTENTIAL FOR SHORT WAVES TO AFFECT THE AREA.
CURRENT FORECAST HAS LOW POPS ACROSS N GA ON MONDAY AND TUESDAY
AND WILL JUST CONTINUE THAT FORECAST FOR NOW AS A COMPROMISE. NO
INSTABILITY TO SPEAK OFF UNTIL TUESDAY AFTERNOON WHERE THERE MIGHT
BE ENOUGH FOR THUNDERSTORMS OVER FAR N GA. UPPER RIDGE OVER THE
AREA FOR WEDNESDAY INTO THURSDAY. KEEPING POPS NIL FOR WEDNESDAY
EXCEPT FOR LOW POPS OVER THE NE MOUNTAINS WHERE SOUTHERLY FLOW AND
SOME INSTABILITY COULD CAUSE AFTERNOON SHOWERS AND STORMS.
TEMPERATURES GENERALLY RUNNING WITHIN 6 DEGREES OF NORMAL THROUGH
THE PERIOD EXCEPT SATURDAY MORNING LOWS ARE RUNNING ABOUT 10-15
DEGREES BELOW NORMAL AND SUNDAY MORNING LOWS RUNNING ABOUT 6-12
DEGREES BELOW NORMAL.
01/BDL
&&
.AVIATION...
00Z UPDATE...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER GA THROUGH THE FORECAST
PERIOD. VFR CONDITIONS WITH A BREEZY NORTHWEST FLOW WILL PREVAIL.
//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
16
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 58 78 47 80 / 5 0 0 0
ATLANTA 59 76 51 78 / 5 0 0 0
BLAIRSVILLE 54 72 42 75 / 20 0 0 0
CARTERSVILLE 57 76 45 80 / 5 0 0 0
COLUMBUS 64 82 54 83 / 5 0 0 0
GAINESVILLE 58 76 49 77 / 20 0 0 0
MACON 60 82 48 82 / 5 0 0 0
ROME 57 76 46 81 / 10 0 0 0
PEACHTREE CITY 57 77 45 79 / 5 0 0 0
VIDALIA 66 86 56 83 / 5 0 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....01
AVIATION...31
000
FXUS62 KCAE 232342
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
742 PM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SHOWERS AND THUNDERSTORMS MOVING INTO NORTHEAST SOUTH
CAROLINA...CLEARING ACROSS MIDLANDS. POPS DECREASING RAPIDLY
ACROSS THE REGION AS DRY AIR ADVECTS IN FROM THE UPSTATE AND NORTH
GEORGIA. LOWS UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
DRYING BEHIND THE FRONT SHOULD DOMINATE FRIDAY THROUGH FRIDAY
NIGHT. MIXING ASSOCIATED WITH THE FRONT SUPPORTED THE WARMER
TEMPERATURE GUIDANCE TONIGHT. HIGH PRESSURE WILL BRING COOLER
DRIER CONDITIONS FRIDAY NIGHT AND SATURDAY. WILL GO WITH GFS MOS
GUIDANCE IN THE MID 40S FRIDAY NIGHT AND MODEL BLEND UPPER 70S
TO LOWER 80S SATURDAY. AIR MASS MODIFIES BY SATURDAY NIGHT WITH
LOWS IN THE LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT WITH UPPER RIDGE WORKING
IN FROM THE WEST. BOTH MODELS SHOW A WEAK SURFACE FRONTAL BOUNDARY
WHICH REMAINS MAINLY TO THE NORTH BUT ECMWF SHOWS THE FRONT A
LITTLE BIT STRONGER THAN THE GFS. THE ECMWF ALSO KEEPS THE FRONT
A LITTLE FARTHER TO THE SOUTH. DRY TO START SUNDAY AND MONDAY BUT
BY THE END OF THE EXTENDED PERIOD...THE AIR MASS MOISTURE INCREASES
AND THE INSTABILITY INCREASES. EXPECT MORE DIURNAL SHOWERS AND
THUNDERSTORMS TUESDAY THROUGH WEDNESDAY. HIGH TEMPERATURES
INCREASE FROM THE LOWER 80S SUNDAY TO THE MID 80S MONDAY AND
TUESDAY TO THE UPPER 80S BY WEDNESDAY. OVERNIGHT LOW TEMPERATURES
ARE EXPECTED TO BE IN THE UPPER 50S SUNDAY NIGHT BUT INCREASE TO
THE LOWER 60S FOR THE REST OF THE PERIOD.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE 24 HOUR TAF PERIOD.
ONLY AN ISOLATED SHOWER OR THUNDERSTORM POSSIBLE THROUGH THIS
EVENING. CHANCES FAR TOO LOW TO INCLUDE MENTION IN THE TAFS. WINDS
ARE EXPECTED TO STAY UP SOME TONIGHT...PLUS SOME DRIER AIR WILL
FILTER IN BEHIND A WEAK SURFACE TROUGH...PRECLUDING ANY FOG/STRATUS
THREAT. BREEZY CONDITIONS EXPECTED FRIDAY...BEHIND A DRY COLD FRONT
THAT WILL COME THROUGH IN THE MORNING.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY FRIDAY AFTERNOON IS EXPECTED TO BE IN THE 20 TO
25 PERCENT RANGE. WINDS APPEAR MARGINAL RED FLAG...EXPECT
SUSTAINED WINDS MAINLY BELOW 20 MPH. WIND GUSTS EXPECTED TO AROUND
25 MPH. FUEL MOISTURE IS HIGH REDUCING FIRE THREAT.
&&
.CLIMATE...
MUCH BELOW NORMAL TEMPERATURES FRIDAY NIGHT/SATURDAY MORNING WITH
LOWS IN THE 40S.
COLUMBIA METRO AIRPORT RECORD LOW MAY 25TH...45 SET IN 1967
AUGUSTA BUSH FIELD RECORD LOW MAY 25TH.......43 SET IN 1951
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 232310
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
710 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATE TONIGHT...WITH DRY
HIGH PRESSURE BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THIS EVENING...ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS...WITH
BEST COVERAGE ACROSS FAR NORTHERN COUNTIES...WILL CONTINUE TO FIRE
AND DISSIPATE ALONG AN INLAND DEWPOINT BOUNDARY AND THE SEA BREEZE
PINNED NEAR THE COAST. AFTER DARK...DIURNAL COOLING WILL TRANSLATE
TO DECREASING PRECIPITATION COVERAGE.
A COLD FRONT ACROSS THE OHIO/TENNESSEE VALLEY WILL MAKE STEADY
PROGRESS SOUTHEAST OVERNIGHT. ANY SHOWERS OR THUNDERSTORMS WILL
ACTUALLY HAVE DISSIPATED WELL BEFORE THE FRONT PUSHES INTO THE
REGION DURING THE PRE DAWN HOURS. HAVE THUS CAPPED RAIN CHANCES
BELOW 15 PERCENT BY MIDNIGHT. WINDS WILL STEADILY VEER FROM WEST
TO NORTHWEST BY DAYBREAK FRIDAY...WITH SKIES LIKELY MOSTLY CLEAR
BY SUNRISE.
LOW TEMPERATURES WILL RANGE FROM THE LOW TO MID 60S AWAY FROM THE
IMMEDIATE COASTLINE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
THE WEATHER WILL BE RELATIVELY QUIET DURING THIS PERIOD AS HIGH
PRESSURE BUILDS IN FROM THE NORTH ON FRIDAY...SETTLING OVER THE AREA
FOR THE WEEKEND. FRIDAY WILL BE THE WARMEST OF THE THREE DAYS AS
NORTHWESTERLY DOWNSLOPE FLOW WILL ALLOW FOR A LITTLE COMPRESSIONAL
HEATING AT LOW LEVELS. AFTERNOON MAX TEMPS WILL MANAGE TO GET TO
NEAR NORMAL UNDER MOSTLY SUNNY SKIES. THE WINDS MAY GET A BIT BREEZY
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS WITH GOOD MIXING
IN THE BOUNDARY LAYER ALLOWING SOMEWHAT STRONGER WINDS TO MIX TO THE
SURFACE.
FRIDAY NIGHT...STRONG COOL ADVECTION SETTLES IN...WITH TEMPERATURES
DROPPING ALL NIGHT. RISING HEIGHTS ALOFT WILL HELP PROMOTE LOW LEVEL
SUBSIDENCE...KEEPING SKIES CLEAR. TEMPS WILL DROP INTO THE UPPER 40S
TO NEAR 50 WEST OF INTERSTATE 95...WITH LOWER 50S ELSEWHERE. A
PERSISTENT 5 TO 10 KNOT WIND WILL KEEP TEMPS FROM DROPPING EVEN
LOWER.
SATURDAY WILL BE COOL AND SUNNY AS A BUBBLE AREA OF HIGH PRESSURE
SETS UP IN THE NEIGHBORHOOD. DEW POINTS WILL DROP INTO THE 30S BY
AFTERNOON AWAY FROM THE COAST...WHICH IS VERY LOW FOR MEMORIAL DAY
WEEKEND. RELATIVE HUMIDITY VALUES BY THEMSELVES WOULD BE LOW
ENOUGH FOR FIRE WEATHER CONCERNS...BUT THE WINDS WILL BE GENERALLY
LESS THAN 10 KNOTS.
NOT MUCH CHANGE EXPECTED ON SUNDAY WITH THE HIGH REMAINING CLOSE BY.
A WEAK LEE TROF MAY DEVELOP BY AFTERNOON IN THE MIDLANDS...ALLOWING
FOR A BIT MORE ROBUST SEA BREEZE TO FORM...BUT THE LACK OF LOW LEVEL
MOISTURE WILL PREVENT ANY CONVECTIVE ACTIVITY. THERE COULD BE A
LITTLE MORE IN THE WAY OF CIRRUS AS A WEAK DISTURBANCE ALOFT ROTATES
AROUND THE DEEP UPPER LOW EXPECTED OVER NEW ENGLAND...BUT IT WONT
SIGNIFICANTLY DENT THE AMOUNT OF SUNSHINE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE REGION WILL BE SANDWICHED BETWEEN TWO AREAS OF HIGH PRESSURE
EARLY IN THE WEEK...THE STRONGER OF THE TWO PASSING ACROSS THE
MID-ATLANTIC REGION AND THE OTHER OVER THE NORTHEAST GULF OF
MEXICO. DEEPENING MOISTURE WILL RESULT IN AT LEAST AN INCREASE IN
CLOUD COVER...BUT IT APPEARS THE RAIN-FREE CONDITIONS SHOULD
PERSIST THROUGH MEMORIAL DAY. ATLANTIC HIGH PRESSURE WILL THEN
BECOME ESTABLISHED THROUGH THE MIDDLE OF NEXT WEEK...SUPPORTING
MAINLY DIURNAL ISOLATED CONVECTION EACH AFTERNOON ALONG AND AHEAD
OF THE SEA BREEZE TUESDAY THROUGH THURSDAY. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BY EARLY NEXT WEEK AND CONTINUE NEAR
SEASONAL NORMS THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH FRIDAY.
EXTENDED AVIATION...VFR CONDITIONS THROUGH THE WEEKEND.
&&
.MARINE...
SOUTHERLY WINDS THIS AFTERNOON WILL VEER OFFSHORE OVERNIGHT...AS A
COLD FRONT SHIFTS THROUGH THE AREA BY DAYBREAK FRIDAY. WIND SPEEDS
WILL PEAK AROUND 15 KT...YET THE OFFSHORE FETCH WILL LIMIT THE
SEAS TO NO HIGHER THAN 4 FT.
THE MAIN PERIOD OF CONCERN WILL BE FRIDAY NIGHT BEHIND THE COLD
FRONT AS WINDS ACCELERATE FROM THE NORTH AND EVENTUALLY NORTH
NORTHEAST. WINDS AND SEAS WILL BE RIGHT AROUND SCA CRITERIA
OFFSHORE...BUT TOO MARGINAL TO ISSUE ANY HEADLINES AT THIS TIME.
WINDS AND SEAS WILL QUICKLY COME BACK DOWN SATURDAY AS THE
PRESSURE GRADIENT COLLAPSES WHILE HIGH PRESSURES SETTLES OVER THE
WATERS.
WINDS WILL BECOME DIURNALLY DRIVEN NEXT WEEK AS THE SURFACE
HIGH MOVES INTO THE ATLANTIC WITH A WEAK RIDGE STRETCHING WESTWARD
OVER THE CWA. SPEEDS SHOULD BE 15 KNOTS OR LESS THE FIRST HALF OF
NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENINGS. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE AS
ASTRONOMICAL FACTORS WILL CAUSE HIGHER THAN TYPICAL TIDES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...SPR/WMS
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...SPR
MARINE...FWA/JAQ/SPR
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 232103
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
503 PM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
INSTABILITY ACROSS THE MIDLANDS WEAK TO MODERATE HOWEVER DRIER AIR
ADVECTING EAST FROM GEORGIA. RADAR SHOWING A FEW SCATTERED SHOWERS
AND THUNDERSTORMS ACROSS EASTERN/NORTH MIDLANDS THIS AFTERNOON.
CLUSTER OF STRONGER THUNDERSTORMS IN THE UPSTATE MOVING SOUTHEAST.
ALTHOUGH DRIER AIR WILL LIMIT CONVECTIVE COVERAGE...LATEST HIGH
RESOLUTION MODELS SUPPORT SCATTERED CONVECTION MAINLY NORTH AND
EAST OF COLUMBIA EARLY THIS EVENING. DRY MID LEVEL AIR SUPPORTS A
HAIL THREAT...BUT OVERALL SEVERE THREAT APPEARS LOW.
TONIGHT...A 20 PERCENT CHANCE EARLY. PLAN ON NO POPS IN THE WEST
AS DRIER AIR MOVES IN FROM THE WEST WITH THE COLD FRONT. LOWS
UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
DRYING BEHIND THE FRONT SHOULD DOMINATE FRIDAY THROUGH FRIDAY
NIGHT. MIXING ASSOCIATED WITH THE FRONT SUPPORTED THE WARMER
TEMPERATURE GUIDANCE TONIGHT. HIGH PRESSURE WILL BRING COOLER
DRIER CONDITIONS FRIDAY NIGHT AND SATURDAY. WILL GO WITH GFS MOS
GUIDANCE IN THE MID 40S FRIDAY NIGHT AND MODEL BLEND UPPER 70S
TO LOWER 80S SATURDAY. AIR MASS MODIFIES BY SATURDAY NIGHT WITH
LOWS IN THE LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT WITH UPPER RIDGE WORKING
IN FROM THE WEST. BOTH MODELS SHOW A WEAK SURFACE FRONTAL BOUNDARY
WHICH REMAINS MAINLY TO THE NORTH BUT ECMWF SHOWS THE FRONT A
LITTLE BIT STRONGER THAN THE GFS. THE ECMWF ALSO KEEPS THE FRONT
A LITTLE FARTHER TO THE SOUTH. DRY TO START SUNDAY AND MONDAY BUT
BY THE END OF THE EXTENDED PERIOD...THE AIR MASS MOISTURE INCREASES
AND THE INSTABILITY INCREASES. EXPECT MORE DIURNAL SHOWERS AND
THUNDERSTORMS TUESDAY THROUGH WEDNESDAY. HIGH TEMPERATURES
INCREASE FROM THE LOWER 80S SUNDAY TO THE MID 80S MONDAY AND
TUESDAY TO THE UPPER 80S BY WEDNESDAY. OVERNIGHT LOW TEMPERATURES
ARE EXPECTED TO BE IN THE UPPER 50S SUNDAY NIGHT BUT INCREASE TO
THE LOWER 60S FOR THE REST OF THE PERIOD.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE 24 HOUR TAF PERIOD.
A SERIES OF WEAK UPPER IMPULSES WILL COME THROUGH LATER TODAY
THROUGH EARLY TONIGHT. WEAK SURFACE TROUGH WILL MOVE THROUGH.
SATELLITE WATER VAPOR IMAGERY INDICATING DRY AIR ALOFT. MESOANALYSIS
INDICATES MODERATE INSTABILITIES. HIGH RES MODELS GENERALLY
PROJECTING LIMITED AREAL COVERAGE OF CONVECTION THROUGH THIS
EVENING...AND MAINLY FAVORING THE NORTH AND EAST FA. LATEST RADAR
INDICATES A FEW SHOWERS DEVELOPING OVER THE CENTRAL MIDLANDS. WILL
HANDLE WITH VCSH AT CAE/CUB/OGB IN THE NEAR TERM...WITH POSSIBILITY
OF HAVING TO AMEND OGB TO INCLUDE A TEMPO OR PREDOMINATE MENTION IN
THE NEAR TERM. WINDS STAYING UP TONIGHT...ALONG WITH SOME DRIER AIR
FILTERING IN...TO PRECLUDE FOG/STRATUS THREAT. BREEZY CONDITIONS
EXPECTED FRIDAY.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KFFC 231948
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
348 PM EDT THU MAY 23 2013
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
UPPER LEVEL TROUGH AND ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH
THE OHIO VALLEY THIS AFTERNOON. ALTHOUGH A DRIER AIR MASS
ACCOMPANIES THE FRONT AND WILL CONTINUE TO MOVE INTO THE
STATE...MOISTURE ASSOCIATED WITH THE TROUGH WILL RETURN TO FAR NORTH
GEORGIA THROUGH THIS EVENING...AND HAVE CONTINUED MENTION OF SLIGHT
CHANCE SHOWERS AND THUNDERSTORMS ACROSS THAT AREA. DIMINISH ANY
REMAINING POPS QUICKLY AFTER 03Z.
MAIN CONCERN THROUGH THE SHORT TERM WILL BE THE TIGHT PRESSURE
GRADIENT ACROSS THE AREA...AND THE ASSOCIATED GUSTY WINDS. AS OF
NOW...MODELS CONSISTENT WITH KEEPING WINDS BELOW WIND ADVISORY
CRITERIA...AND HAVE HELD OFF ON ISSUING ANYTHING AT THIS TIME. IN
GENERAL...EXPECTING NORTHWEST WINDS OF 10 UP TO 20 MPH WITH GUSTS TO
30 MPH. OVERNIGHT SHIFT WILL NEED TO RE-EVALUATE.
TEMPERATURES WILL BE AT OR SLIGHTLY BELOW NORMAL THROUGH THE
WEEKEND. HAVE GENERALLY GONE WITH A MODEL BLEND FOR TEMPERATURES AND
DEWPOINTS.
31
.LONG TERM /SATURDAY THROUGH THURSDAY/...
NO MAJOR CHANGES MADE TO THE CURRENT EXTENDED FORECAST. DRY
WEATHER IS EXPECTED TO CONTINUE ACROSS THE AREA THROUGH SUNDAY AND
FOR THE MOST PART BASED ON THE GFS...THROUGH THURSDAY. HOWEVER THE
EUROPEAN MODEL IS INDICATING A WETTER NW FLOW ALOFT ACROSS N AND
PARTS OF CENTRAL GA STARTING SUNDAY NIGHT WITH A WEAKER UPPER
RIDGE AND GREATER POTENTIAL FOR SHORT WAVES TO AFFECT THE AREA.
CURRENT FORECAST HAS LOW POPS ACROSS N GA ON MONDAY AND TUESDAY
AND WILL JUST CONTINUE THAT FORECAST FOR NOW AS A COMPROMISE. NO
INSTABILITY TO SPEAK OFF UNTIL TUESDAY AFTERNOON WHERE THERE MIGHT
BE ENOUGH FOR THUNDERSTORMS OVER FAR N GA. UPPER RIDGE OVER THE
AREA FOR WEDNESDAY INTO THURSDAY. KEEPING POPS NIL FOR WEDNESDAY
EXCEPT FOR LOW POPS OVER THE NE MOUNTAINS WHERE SOUTHERLY FLOW AND
SOME INSTABILITY COULD CAUSE AFTERNOON SHOWERS AND STORMS.
TEMPERATURES GENERALLY RUNNING WITHIN 6 DEGREES OF NORMAL THROUGH
THE PERIOD EXCEPT SATURDAY MORNING LOWS ARE RUNNING ABOUT 10-15
DEGREES BELOW NORMAL AND SUNDAY MORNING LOWS RUNNING ABOUT 6-12
DEGREES BELOW NORMAL.
01/BDL
&&
.AVIATION...
18Z UPDATE...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WINDS ARE THE MAIN
FORECAST CONCERN. NORTHWEST WINDS WILL BE 12-16KT WITH GUSTS TO
22-26KT TODAY AND FRIDAY AFTERNOON. WINDS WILL BE SLIGHTLY LIGHTER
/7-12KT/ OVERNIGHT BEFORE INCREASING AGAIN FRIDAY.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 58 78 47 80 / 5 0 0 0
ATLANTA 59 76 51 78 / 5 0 0 0
BLAIRSVILLE 54 72 42 75 / 20 0 0 0
CARTERSVILLE 57 76 45 80 / 5 0 0 0
COLUMBUS 64 82 54 83 / 5 0 0 0
GAINESVILLE 58 76 49 77 / 20 0 0 0
MACON 60 82 48 82 / 5 0 0 0
ROME 57 76 46 81 / 10 0 0 0
PEACHTREE CITY 57 77 45 79 / 5 0 0 0
VIDALIA 66 86 56 83 / 5 0 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....01
AVIATION...31
000
FXUS62 KCHS 231947
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
347 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATE TONIGHT...WITH DRY
HIGH PRESSURE BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
DESPITE AN UPPER SHORTWAVE MOVING OVER THE AREA AND A PRE-FRONTAL
SURFACE TROUGH DIRECTLY ACROSS THE MID ATLANTIC AND SOUTHEAST
STATES...CONVECTION HAS STRUGGLED TO DEVELOP BY LATE AFTERNOON.
INSTABILITY PARAMETERS ARE RELATIVELY WEAK FOR LATE SPRING...AND
WITH DEEP MOISTURE STEADILY DIMINISHING FROM WEST TO
EAST...ISOLATED CONVECTION HAS MAINLY BEEN IN THE FORM OF SHOWERS
AND WEAK BRIEF THUNDERSTORMS. HAVE DECREASED RAIN POTENTIAL FOR
THE REMAINDER OF THE DAYTIME HOURS...INDICATING JUST SLIGHT
CHANCES MAINLY ACROSS THE CHARLESTON TRI COUNTY REGION AND ALONG
THE SEABREEZE FROM COASTAL SOUTH CAROLINA THROUGH COASTAL GEORGIA.
DEPENDING UPON RADAR TRENDS DURING THE NEXT HOUR OR TWO...THESE
RAIN CHANCES COULD EVEN BE OVERDONE THROUGH THE EVENING.
A COLD FRONT ACROSS THE OHIO/TENNESSEE VALLEY WILL MAKE STEADY
PROGRESS SOUTHEAST OVERNIGHT. ANY SHOWERS OR THUNDERSTORMS WILL
ACTUALLY HAVE DISSIPATED WELL BEFORE THE FRONT PUSHES INTO THE
REGION DURING THE PRE DAWN HOURS. HAVE THUS CAPPED RAIN CHANCES
BELOW 15 PERCENT BY MIDNIGHT. WINDS WILL STEADILY VEER FROM WEST
TO NORTHWEST BY DAYBREAK FRIDAY...WITH SKIES LIKELY MOSTLY CLEAR
BY SUNRISE.
LOW TEMPERATURES WILL RANGE FROM THE LOW TO MID 60S AWAY FROM THE
IMMEDIATE COASTLINE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
THE WEATHER WILL BE RELATIVELY QUIET DURING THIS PERIOD AS HIGH
PRESSURE BUILDS IN FROM THE NORTH ON FRIDAY...SETTLING OVER THE AREA
FOR THE WEEKEND. FRIDAY WILL BE THE WARMEST OF THE THREE DAYS AS
NORTHWESTERLY DOWNSLOPE FLOW WILL ALLOW FOR A LITTLE COMPRESSIONAL
HEATING AT LOW LEVELS. AFTERNOON MAX TEMPS WILL MANAGE TO GET TO
NEAR NORMAL UNDER MOSTLY SUNNY SKIES. THE WINDS MAY GET A BIT BREEZY
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS WITH GOOD MIXING
IN THE BOUNDARY LAYER ALLOWING SOMEWHAT STRONGER WINDS TO MIX TO THE
SURFACE.
FRIDAY NIGHT...STRONG COOL ADVECTION SETTLES IN...WITH TEMPERATURES
DROPPING ALL NIGHT. RISING HEIGHTS ALOFT WILL HELP PROMOTE LOW LEVEL
SUBSIDENCE...KEEPING SKIES CLEAR. TEMPS WILL DROP INTO THE UPPER 40S
TO NEAR 50 WEST OF INTERSTATE 95...WITH LOWER 50S ELSEWHERE. A
PERSISTENT 5 TO 10 KNOT WIND WILL KEEP TEMPS FROM DROPPING EVEN
LOWER.
SATURDAY WILL BE COOL AND SUNNY AS A BUBBLE AREA OF HIGH PRESSURE
SETS UP IN THE NEIGHBORHOOD. DEW POINTS WILL DROP INTO THE 30S BY
AFTERNOON AWAY FROM THE COAST...WHICH IS VERY LOW FOR MEMORIAL DAY
WEEKEND. RELATIVE HUMIDITY VALUES BY THEMSELVES WOULD BE LOW
ENOUGH FOR FIRE WEATHER CONCERNS...BUT THE WINDS WILL BE GENERALLY
LESS THAN 10 KNOTS.
NOT MUCH CHANGE EXPECTED ON SUNDAY WITH THE HIGH REMAINING CLOSE BY.
A WEAK LEE TROF MAY DEVELOP BY AFTERNOON IN THE MIDLANDS...ALLOWING
FOR A BIT MORE ROBUST SEA BREEZE TO FORM...BUT THE LACK OF LOW LEVEL
MOISTURE WILL PREVENT ANY CONVECTIVE ACTIVITY. THERE COULD BE A
LITTLE MORE IN THE WAY OF CIRRUS AS A WEAK DISTURBANCE ALOFT ROTATES
AROUND THE DEEP UPPER LOW EXPECTED OVER NEW ENGLAND...BUT IT WONT
SIGNIFICANTLY DENT THE AMOUNT OF SUNSHINE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE REGION WILL BE SANDWICHED BETWEEN TWO AREAS OF HIGH PRESSURE
EARLY IN THE WEEK...THE STRONGER OF THE TWO PASSING ACROSS THE
MID-ATLANTIC REGION AND THE OTHER OVER THE NORTHEAST GULF OF
MEXICO. DEEPENING MOISTURE WILL RESULT IN AT LEAST AN INCREASE IN
CLOUD COVER...BUT IT APPEARS THE RAIN-FREE CONDITIONS SHOULD
PERSIST THROUGH MEMORIAL DAY. ATLANTIC HIGH PRESSURE WILL THEN
BECOME ESTABLISHED THROUGH THE MIDDLE OF NEXT WEEK...SUPPORTING
MAINLY DIURNAL ISOLATED CONVECTION EACH AFTERNOON ALONG AND AHEAD
OF THE SEA BREEZE TUESDAY THROUGH THURSDAY. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BY EARLY NEXT WEEK AND CONTINUE NEAR
SEASONAL NORMS THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL PREVAIL AT BOTH KCHS AND KSAV THROUGH 18Z
FRIDAY. ISOLATED SHOWER ACTIVITY WILL CONTINUE FOR THE REMAINDER
OF THE AFTERNOON HOURS...HOWEVER DO NOT EXPECT ANY SIGNIFICANT
IMPACTS AT EITHER TERMINAL. ANY SHOWERS/THUNDERSTORMS WILL
STEADILY DIMINISH IN COVERAGE...WHILE SKIES BEGIN CLEARING THIS
EVENING. A COLD FRONT PROGRESSING THROUGH THE REGION OVERNIGHT
WILL SUPPORT STEADILY VEERING WINDS...WITH NORTHWEST FLOW EXPECTED
BY DAYBREAK FRIDAY.
EXTENDED AVIATION...VFR CONDITIONS THROUGH THE WEEKEND.
&&
.MARINE...
SOUTHERLY WINDS THIS AFTERNOON WILL VEER OFFSHORE OVERNIGHT...AS A
COLD FRONT SHIFTS THROUGH THE AREA BY DAYBREAK FRIDAY. WIND SPEEDS
WILL PEAK AROUND 15 KT...YET THE OFFSHORE FETCH WILL LIMIT THE
SEAS TO NO HIGHER THAN 4 FT.
THE MAIN PERIOD OF CONCERN WILL BE FRIDAY NIGHT BEHIND THE COLD
FRONT AS WINDS ACCELERATE FROM THE NORTH AND EVENTUALLY NORTH
NORTHEAST. WINDS AND SEAS WILL BE RIGHT AROUND SCA CRITERIA
OFFSHORE...BUT TOO MARGINAL TO ISSUE ANY HEADLINES AT THIS TIME.
WINDS AND SEAS WILL QUICKLY COME BACK DOWN SATURDAY AS THE
PRESSURE GRADIENT COLLAPSES WHILE HIGH PRESSURES SETTLES OVER THE
WATERS.
WINDS WILL BECOME DIURNALLY DRIVEN NEXT WEEK AS THE SURFACE
HIGH MOVES INTO THE ATLANTIC WITH A WEAK RIDGE STRETCHING WESTWARD
OVER THE CWA. SPEEDS SHOULD BE 15 KNOTS OR LESS THE FIRST HALF OF
NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENINGS. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE AS
ASTRONOMICAL FACTORS WILL CAUSE HIGHER THAN TYPICAL TIDES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WMS
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...WMS
MARINE...FWA/JAQ
TIDES/COASTAL FLOODING...FWA
000
FXUS62 KCAE 231936
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
336 PM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THIS AFTERNOON...MODEL FORECAST SOUNDINGS SHOW A CONDITIONALLY
UNSTABLE AIRMASS WITH A WEAK MID LEVEL CAP. MODELS GIVE AFTERNOON
CAPES 1000-2000 J/KG...LIS -5/-6 AND TOTALS AROUND 45. PW VALUES
INITIALLY AROUND 1.4 INCHES BUT DRIER AIR WORKS IN FROM WEST TO
LOWER PW TO 1.20 INCHES. KIS LESS THAN 30 AS MOISTURE IS MAINLY
BELOW 10 KFT. HOWEVER...AFTERNOON HEATING MAY LIFT MOISTURE ENOUGH
FOR A FEW THUNDERSTORMS MAINLY IN THE EAST PART. SPC HAS AREA IN
GENERAL THUNDERSTORMS OUTLOOK BUT IF HIGH ELEVATED CORES DEVELOP
THE POTENTIAL EXISTS FOR PERHAPS ISOLATED STRONG TO SEVERE STORMS
BUT AGAIN MAINLY IN THE EAST. HAVE MAINLY 20-30 PERCENT CHANCE BUT
IN FAR EAST AND NORTHEAST WILL KEEP 40-60 PERCENT CHANCE. HIGH
TEMPERATURES IN THE MID TO UPPER 80S.
TONIGHT...A 20 PERCENT CHANCE IN THE EAST DURING THE EVENING.
PLAN ON NO POPS IN THE WEST AS DRIER AIR MOVES IN FROM THE WEST
WITH THE COLD FRONT. LOWS UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
DRYING BEHIND THE FRONT SHOULD DOMINATE FRIDAY THROUGH FRIDAY
NIGHT. MIXING ASSOCIATED WITH THE FRONT SUPPORTED THE WARMER
TEMPERATURE GUIDANCE TONIGHT. HIGH PRESSURE WILL BRING COOLER
DRIER CONDITIONS FRIDAY NIGHT AND SATURDAY. WILL GO WITH GFS MOS
GUIDANCE IN THE MID 40S FRIDAY NIGHT AND MODEL BLEND UPPER 70S
TO LOWER 80S SATURDAY. AIRMASS MODIFIES BY SATURDAY NIGHT WITH
LOWS IN THE LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT WITH UPPER RIDGE WORKING
IN FROM THE WEST. BOTH MODELS SHOW A WEAK SURFACE FRONTAL BOUNDARY
WHICH REMAINS MAINLY TO THE NORTH BUT ECMWF SHOWS THE FRONT A
LITTLE BIT STRONGER THAN THE GFS. THE ECMWF ALSO KEEPS THE FRONT
A LITTLE FARTHER TO THE SOUTH. DRY TO START SUNDAY AND MONDAY BUT
BY THE END OF THE EXTENDED PERIOD...THE AIRMASS MOISTURE INCREASES
AND THE INSTABILITY INCREASES. EXPECT MORE DIURNAL SHOWERS AND
THUNDERSTORMS TUESDAY THROUGH WEDNESDAY. HIGH TEMPERATURES
INCREASE FROM THE LOWER 80S SUNDAY TO THE MID 80S MONDAY AND
TUESDAY TO THE UPPER 80S BY WEDNESDAY. OVERNIGHT LOW TEMPERATURES
ARE EXPECTED TO BE IN THE UPPER 50S SUNDAY NIGHT BUT INCREASE TO
THE LOWER 60S FOR THE REST OF THE PERIOD.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE 24 HOUR TAF PERIOD.
A SERIES OF WEAK UPPER IMPULSES WILL COME THROUGH LATER TODAY
THROUGH EARLY TONIGHT. WEAK SURFACE TROUGH WILL MOVE THROUGH.
SATELLITE WATER VAPOR IMAGERY INDICATING DRY AIR ALOFT. MESOANALYSIS
INDICATES MODERATE INSTABILITIES. HIGH RES MODELS GENERALLY
PROJECTING LIMITED AREAL COVERAGE OF CONVECTION THROUGH THIS
EVENING...AND MAINLY FAVORING THE NORTH AND EAST FA. LATEST RADAR
INDICATES A FEW SHOWERS DEVELOPING OVER THE CENTRAL MIDLANDS. WILL
HANDLE WITH VCSH AT CAE/CUB/OGB IN THE NEAR TERM...WITH POSSIBILITY
OF HAVING TO AMEND OGB TO INCLUDE A TEMPO OR PREDOMINATE MENTION IN
THE NEAR TERM. WINDS STAYING UP TONIGHT...ALONG WITH SOME DRIER AIR
FILTERING IN...TO PRECLUDE FOG/STRATUS THREAT. BREEZY CONDITIONS
EXPECTED FRIDAY.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCAE 231843
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
243 PM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THIS AFTERNOON...MODEL FORECAST SOUNDINGS SHOW A CONDITIONALLY
UNSTABLE AIRMASS WITH A WEAK MID LEVEL CAP. MODELS GIVE AFTERNOON
CAPES 1000-2000 J/KG...LIS -5/-6 AND TOTALS AROUND 45. PW VALUES
INITIALLY AROUND 1.4 INCHES BUT DRIER AIR WORKS IN FROM WEST TO
LOWER PW TO 1.20 INCHES. KIS LESS THAN 30 AS MOISTURE IS MAINLY
BELOW 10 KFT. HOWEVER...AFTERNOON HEATING MAY LIFT MOISTURE ENOUGH
FOR A FEW THUNDERSTORMS MAINLY IN THE EAST PART. SPC HAS AREA IN
GENERAL THUNDERSTORMS OUTLOOK BUT IF HIGH ELEVATED CORES DEVELOP
THE POTENTIAL EXISTS FOR PERHAPS ISOLATED STRONG TO SEVERE STORMS
BUT AGAIN MAINLY IN THE EAST. HAVE MAINLY 20-30 PERCENT CHANCE BUT
IN FAR EAST AND NORTHEAST WILL KEEP 40-60 PERCENT CHANCE. HIGH
TEMPERATURES IN THE MID TO UPPER 80S.
TONIGHT...A 20 PERCENT CHANCE IN THE EAST DURING THE EVENING.
PLAN ON NO POPS IN THE WEST AS DRIER AIR MOVES IN FROM THE WEST
WITH THE COLD FRONT. LOWS UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
DRYING BEHIND THE FRONT SHOULD DOMINATE FRIDAY THROUGH FRIDAY
NIGHT. MIXING ASSOCIATED WITH THE FRONT SUPPORTED THE WARMER
TEMPERATURE GUIDANCE TONIGHT. HIGH PRESSURE WILL BRING COOLER
DRIER CONDITIONS FRIDAY NIGHT AND SATURDAY. WILL GO WITH GFS MOS
GUIDANCE IN THE MID 40S FRIDAY NIGHT AND MODEL BLEND UPPER 70S
TO LOWER 80S SATURDAY. AIRMASS MODIFIES BY SATURDAY NIGHT WITH
LOWS IN THE LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT WITH UPPER RIDGE WORKING
IN FROM THE WEST. BOTH MODELS SHOW A WEAK SURFACE FRONTAL BOUNDARY
WHICH REMAINS MAINLY TO THE NORTH BUT ECMWF SHOWS THE FRONT A
LITTLE BIT STRONGER THAN THE GFS. THE ECMWF ALSO KEEPS THE FRONT
A LITTLE FARTHER TO THE SOUTH. DRY TO START SUNDAY AND MONDAY BUT
BY THE END OF THE EXTENDED PERIOD...THE AIRMASS MOISTURE INCREASES
AND THE INSTABILITY INCREASES. EXPECT MORE DIURNAL SHOWERS AND
THUNDERSTORMS TUESDAY THROUGH WEDNESDAY. HIGH TEMPERATURES
INCREASE FROM THE LOWER 80S SUNDAY TO THE MID 80S MONDAY AND
TUESDAY TO THE UPPER 80S BY WEDNESDAY. OVERNIGHT LOW TEMPERATURES
ARE EXPECTED TO BE IN THE UPPER 50S SUNDAY NIGHT BUT INCREASE TO
THE LOWER 60S FOR THE REST OF THE PERIOD.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SATELLITE SHOWS PLENTY OF SC/CU AROUND THIS EARLY AFTERNOON. MOST
TAF SITES HAVE RETURNED TO VFR CONDITIONS...EXCEPT BOTH AGS/DNL
REPORTING MVFR CONDITIONS. EXPECT WITH ADDITIONAL DAYTIME HEATING
THAT CLOUD BASIS WILL RISE BETWEEN 19Z TO 20Z AND VFR CONDITIONS
WILL RETURN. AT THIS TIME...CONVECTION APPEARS TO BE MAINLY
CONCENTRATED ACROSS THE NORTHERN MIDLANDS/PEE DEE AND ALONG THE
COAST. THIS IS IN GOOD AGREEMENT WITH LOCAL/SPC WRF MODEL RUNS. WILL
CONTINUE WITH VFR CONDITIONS THROUGH THE PERIOD. WITH PASSAGE OF
COLD FRONT LATE THIS EVENING/OVERNIGHT...MODELS INDICATE A 30 KT LOW
LEVEL JET. THIS WILL KEEP WINDS UP SLIGHTLY OVERNIGHT BEFORE
BECOMING MORE BREEZE ON FRIDAY. ON FRIDAY...WINDS WILL BE FROM THE
NORTHWEST BEHIND THE FRONT AND BREEZY WITH WINDS AVERAGE 10 TO 15
KTS WITH GUSTS UP TO 25 KTS AT TIMES.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 231801
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
201 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATE TONIGHT...WITH DRY
HIGH PRESSURE BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE DISTINCT SHORTWAVE PROGRESSING TOWARD THE FORECAST AREA FROM
THE WEST IS EVIDENT IN WATER VAPOR IMAGERY AS A NOTABLE BOUNDARY
BETWEEN DEEP MOISTURE OVER SOUTH CAROLINA/GEORGIA COASTAL AREAS
AND DRIER AIR FURTHER UPSTATE AND INLAND. THE MAIN COLD FRONT
ASSOCIATED WITH THE UPPER TROUGH AXIS IN THE OHIO VALLEY WILL
REMAIN TO THE NORTHWEST THROUGH THE DAYTIME HOURS...HOWEVER A PRE
FRONTAL TROUGH SEEN IN LATEST MESOANALYSIS WILL PROVIDE SOME
ADDITIONAL CONVERGENCE COINCIDENT WITH THE TIMING OF THE SHORTWAVE
ENERGY. THE ORIENTATION AND MOVEMENT OF THE SURFACE TROUGH HAS
SUPPORTED MORE SOLID DOWNSLOPE FLOW ACROSS THE GEORGIA
COUNTIES...WHILE SOUTH CAROLINA ZONES REMAIN WITHIN A MORE
SOUTHWEST FLOW FOR THE NEXT SEVERAL HOURS. THE DOWNSLOPE FLOW
ACROSS SOUTHERN LOCATIONS COULD LIMIT CONVECTIVE DEVELOPMENT LATER
TODAY.
SHOWERS CONTINUE TO DEVELOP ACROSS MAINLY CHARLESTON AND BERKELEY
COUNTIES...WHILE LATEST RADAR TRENDS ARE INDICATING ISOLATED SHOWERS
BEGINNING TO INITIATE WEST OF INTERSTATE 95 IN SOUTHEAST GEORGIA.
LATEST THINKING IS THAT SHOWERS/THUNDERSTORMS WILL CONTINUE OVER
THE TRI COUNTY...WITH ISOLATED CONVECTION SPREADING SOUTHWARD INTO
THE GEORGIA COASTAL ZONES ALONG THE SEABREEZE. HAVE INDICATED 30
PERCENT RAIN CHANCES IN THE FAVORED NORTHERN COASTAL AREAS THIS
AFTERNOON...WITH SLIGHT CHANCES INLAND SOUTH CAROLINA AND ALONG
THE GEORGIA COASTLINE. HAVE CAPPED RAIN CHANCES BELOW 15 PERCENT
FOR THE INLAND GEORGIA ZONES WHERE THE AFOREMENTIONED DOWNSLOPE
FLOW AND EARLIER INTRUSION OF DRIER AIR WILL SUPPRESS CONVECTIVE
DEVELOPMENT. MODIFYING THE CHS UPPER AIR SOUNDING FOR AFTERNOON
TEMPERATURES AND DEWPOINTS REVEALS ONLY MARGINAL INSTABILITY...AND
WITH CONTINUED WEAK LAPSE RATES AND WIND PROFILES...SEVERE
POTENTIAL IS LOW AGAIN TODAY.
STRATOCUMULUS QUICKLY DEVELOPED ACROSS SOUTH CENTRAL GEORGIA AND
HAS SHIFTED INTO THE CLEAR AREAS OF SOUTHEAST GEORGIA BY EARLY
AFTERNOON. AS A RESULT...MOST OF THE FORECAST AREA WILL REMAIN
PARTLY CLOUDY TO MOSTLY CLOUDY THROUGHOUT THE AFTERNOON
HOURS...WITH THICKEST SKY COVER ACROSS THE NORTHERN ZONES. CURRENT
FORECAST TEMPERATURES ARE IN DECENT AGREEMENT WITH LATEST
TEMPERATURES...AND WILL THUS MAINTAIN ONGOING FORECAST HIGHS
RANGING FROM THE UPPER 80S INLAND TO THE LOW TO MID 80S ALONG THE
COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THE COLD FRONT WILL MOVE THROUGH SHORTLY AFTER MIDNIGHT TONIGHT
WITH SLIGHTLY DRIER AIR BEGINNING TO FILTER INTO THE REGION.
MOSTLY CLEAR SKIES EXPECTED WITH TEMPERATURES IN THE LOWER 60S.
FRIDAY AND FRIDAY NIGHT...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE
MID-ATLANTIC REGION ON FRIDAY. IN WAKE OF THE DEPARTING COLD
FRONT...A DEEP LAYERED NORTHWEST FLOW WILL PREVAIL THROUGH MUCH OF
THE DAY. THE DOWNSLOPE FLOW WILL RESULT IN DRYING ACROSS THE AREA
AND WILL ALSO NEGATE MOST OF THE INITIAL SURGE OF COLD AIR ADVECTION
AS HIGHS SHOULD STILL BE IN THE MID TO UPPER 80S. UNDER MOSTLY SUNNY
SKIES...BREEZY CONDITIONS ARE ALSO EXPECTED. THEN...AS THE UPPER
TROUGH PASSES OFF THE MID-ATLANTIC COAST FRIDAY EVENING...IT WILL
PUSH A SECONDARY COLD FRONT ACROSS THE AREA ALLOWING HIGH PRESSURE
TO BUILD FROM THE GREAT LAKES REGION. THE AIR MASS WILL BEGIN TO
MODIFY SIGNIFICANTLY FOLLOWING THE SECONDARY COLD FRONT WITH
TEMPERATURES PLUMMETING INTO THE UPPER 40S AND LOWER 50S FRIDAY
NIGHT ON A NORTHERLY FLOW.
SATURDAY AND SATURDAY NIGHT...A VERY DRY AIR MASS WILL SETTLE OVER
THE REGION SATURDAY AS HIGH PRESSURE CONTINUES TO BUILD IN FROM THE
GREAT LAKES REGION. PRECIPITABLE WATER VALUES OF .25 TO .40 INCHES
WILL BE ABOUT AS LOW AS THEY CAN GET FOR THIS TIME OF YEAR...OR MORE
THAN 2 STANDARD DEVIATIONS BELOW NORMAL. FORECAST THICKNESS VALUES
ONLY SUPPORT HIGHS IN THE MID TO UPPER 70S...BUT GIVEN FULL SUNSHINE
AND THE HIGHER SUN ANGLE THIS TIME OF YEAR...WILL INDICATE HIGHS IN
THE UPPER 70S TO LOWER 80S ACROSS THE AREA. ANOTHER UNSEASONABLY
COOL NIGHT IS EXPECTED SATURDAY NIGHT...WITH LOWS IN THE LOWER TO
MID 50S.
SUNDAY...A WEAK PRESSURE PATTERN WILL PREVAIL OVER THE REGION. AN
INCREASE IN MID AND HIGH LEVEL MOISTURE WILL SUPPORT SOME CLOUD
COVER BUT THE AIR MASS IS TOO DRY STILL FOR ANY SHOWERS TO DEVELOP.
HIGHS SHOULD BE IN THE LOWER TO MID 80S ACROSS MUCH OF THE AREA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE REGION WILL BE SANDWICHED BETWEEN TWO AREAS OF HIGH PRESSURE
EARLY IN THE WEEK...THE STRONGER OF THE TWO PASSING ACROSS THE
MID-ATLANTIC REGION AND THE OTHER OVER THE NORTHEAST GULF OF MEXICO.
DEEPENING MOISTURE WILL RESULT IN AT LEAST AN INCREASE IN CLOUD
COVER...BUT IT APPEARS THE RAIN-FREE CONDITIONS SHOULD PERSIST
THROUGH MEMORIAL DAY. ATLANTIC HIGH PRESSURE WILL THEN BECOME
ESTABLISHED THROUGH THE MIDDLE OF NEXT WEEK...SUPPORTING MAINLY
DIURNAL ISOLATED CONVECTION EACH AFTERNOON ALONG AND AHEAD OF THE
SEA BREEZE TUESDAY THROUGH THURSDAY. TEMPERATURES WILL MODERATE TO
NEAR NORMAL BY EARLY NEXT WEEK AND CONTINUE NEAR SEASONAL NORMS
THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL PREVAIL AT BOTH KCHS AND KSAV THROUGH 18Z
FRIDAY. SCATTERED SHOWERS HAVE ALREADY DEVELOPED IN ASSOCIATION
WITH A PRE-FRONTAL TROUGH ACROSS SOUTHEAST SOUTH CAROLINA...WITH
EVIDENCE OF ISOLATED ACTIVITY ALSO INITIATING ALONG THE SEABREEZE
WEST OF INTERSTATE 95 IN SOUTHEAST GEORGIA. AT THIS
POINT...CONFIDENCE IN COVERAGE NEAR KSAV IS TOO LOW TO MENTION IN
THE TAF FOR THIS AFTERNOON. WILL INCLUDE VCSH AT KCHS FOR THE
NEXT FEW HOURS DUE TO THE ACTIVITY TO THE EAST. WILL CONTINUE TO
MONITOR RADAR TRENDS IN CASE AMENDMENTS ARE NEEDED IF CONVECTION
NEARS THE TERMINALS. EXPECT ANY SHOWERS/THUNDERSTORMS TO DIMINISH
AND SKIES TO BEGIN CLEARING THIS EVENING. A COLD FRONT PROGRESSING
THROUGH THE REGION OVERNIGHT WILL SUPPORT STEADILY VEERING
WINDS...WITH NORTHWEST FLOW EXPECTED BY DAYBREAK FRIDAY.
EXTENDED AVIATION...VFR CONDITIONS WILL PREVAIL. GUSTY WINDS ARE
POSSIBLE FRIDAY AFTERNOON.
&&
.MARINE...
WINDS AND SEAS WILL BE FAIRLY BENIGN TODAY...BEFORE WINDS
INCREASE OUT OF THE SOUTHWEST AND WEST TONIGHT AS A COLD FRONT
PUSHES THROUGH THE WATERS. WIND SPEEDS WILL INCREASE TO AROUND 15
KT...YET THE OFFSHORE FETCH WILL LIMIT THE BUILDING OF SEAS TO NO
HIGHER THAN 4 FT.
FRIDAY THROUGH TUESDAY...A NORTHWEST FLOW WILL DEVELOP ON FRIDAY IN
WAKE OF A DEPARTING COLD FRONT. A SECONDARY COLD FRONT WILL THEN
MOVE THROUGH BY FRIDAY EVENING...WITH A STRONGER NORTHERLY SURGE
DEVELOPING IN ITS WAKE FRIDAY NIGHT INTO EARLY SATURDAY...POSSIBLY
RESULTING IN SMALL CRAFT ADVISORY CONDITIONS OVER A PORTION OF THE
WATERS.
CONDITIONS WILL THEN IMPROVE LATER IN THE WEEKEND WITH WINDS/SEAS
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH
EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WMS
SHORT TERM...JAQ/JRL
LONG TERM...JAQ
AVIATION...WMS
MARINE...JAQ/JRL
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 231750
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
150 PM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...MODEL FORECAST SOUNDINGS SHOW A CONDITIONALLY
UNSTABLE AIRMASS WITH A WEAK MID LEVEL CAP. MODELS GIVE AFTERNOON
CAPES 1000-2000 J/KG...LIS -5/-6 AND TOTALS AROUND 45. PW VALUES
INITIALLY AROUND 1.4 INCHES BUT DRIER AIR WORKS IN FROM WEST TO
LOWER PW TO 1.20 INCHES. KIS LESS THAN 30 AS MOISTURE IS MAINLY
BELOW 10 KFT. HOWEVER...AFTERNOON HEATING MAY LIFT MOISTURE ENOUGH
FOR A FEW THUNDERSTORMS MAINLY IN THE EAST PART. SPC HAS AREA IN
GENERAL THUNDERSTORMS OUTLOOK BUT IF HIGH ELEVATED CORES DEVELOP
THE POTENTIAL EXISTS FOR PERHAPS ISOLATED STRONG TO SEVERE STORMS
BUT AGAIN MAINLY IN THE EAST. HAVE MAINLY 20-30 PERCENT CHANCE BUT
IN FAR EAST AND NORTHEAST WILL KEEP 40-60 PERCENT CHANCE. HIGH
TEMPERATURES IN THE MID TO UPPER 80S.
TONIGHT...A 20 PERCENT CHANCE IN THE EAST DURING THE EVENING.
PLAN ON NO POPS IN THE WEST AS DRIER AIR MOVES IN FROM THE WEST
WITH THE COLD FRONT. LOWS UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
DRYING BEHIND THE FRONT SHOULD DOMINATE FRIDAY THROUGH FRIDAY
NIGHT. MIXING ASSOCIATED WITH THE FRONT SUPPORTED THE WARMER
TEMPERATURE GUIDANCE TONIGHT. HIGH PRESSURE WILL BRING COOLER
DRIER CONDITIONS FRIDAY NIGHT AND SATURDAY. WILL GO WITH GFS MOS
GUIDANCE IN THE MID 40S FRIDAY NIGHT AND MODEL BLEND UPPER 70S
TO LOWER 80S SATURDAY. AIRMASS MODIFIES BY SATURDAY NIGHT WITH
LOWS IN THE LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MEDIUM RANGE MODELS IN GOOD AGREEMENT WITH UPPER RIDGE WORKING
IN FROM THE WEST. BOTH MODELS SHOW A WEAK SURFACE FRONTAL BOUNDARY
WHICH REMAINS MAINLY TO THE NORTH BUT ECMWF SHOWS THE FRONT A
LITTLE BIT STRONGER THAN THE GFS. THE ECMWF ALSO KEEPS THE FRONT
A LITTLE FARTHER TO THE SOUTH. DRY TO START SUNDAY AND MONDAY BUT
BY THE END OF THE EXTENDED PERIOD...THE AIRMASS MOISTURE INCREASES
AND THE INSTABILITY INCREASES. EXPECT MORE DIURNAL SHOWERS AND
THUNDERSTORMS TUESDAY THROUGH THURSDAY. HIGH TEMPERATURES INCREASE
FROM THE LOWER 80S SUNDAY TO THE MID 80S MONDAY AND TUESDAY TO
THE UPPER 80S BY THURSDAY. OVERNIGHT LOW TEMPERATURES ARE EXPECTED
TO BE IN THE UPPER 50S SUNDAY NIGHT BUT INCREASE TO THE LOWER 60S
FOR THE REST OF THE PERIOD.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SATELLITE SHOWS PLENTY OF SC/CU AROUND THIS EARLY AFTERNOON. MOST
TAF SITES HAVE RETURNED TO VFR CONDITIONS...EXCEPT BOTH AGS/DNL
REPORTING MVFR CONDITIONS. EXPECT WITH ADDITIONAL DAYTIME HEATING
THAT CLOUD BASIS WILL RISE BETWEEN 19Z TO 20Z AND VFR CONDITIONS
WILL RETURN. AT THIS TIME...CONVECTION APPEARS TO BE MAINLY
CONCENTRATED ACROSS THE NORTHERN MIDLANDS/PEE DEE AND ALONG THE
COAST. THIS IS IN GOOD AGREEMENT WITH LOCAL/SPC WRF MODEL RUNS. WILL
CONTINUE WITH VFR CONDITIONS THROUGH THE PERIOD. WITH PASSAGE OF
COLD FRONT LATE THIS EVENING/OVERNIGHT...MODELS INDICATE A 30 KT LOW
LEVEL JET. THIS WILL KEEP WINDS UP SLIGHTLY OVERNIGHT BEFORE
BECOMING MORE BREEZE ON FRIDAY. ON FRIDAY...WINDS WILL BE FROM THE
NORTHWEST BEHIND THE FRONT AND BREEZY WITH WINDS AVERAGE 10 TO 15
KTS WITH GUSTS UP TO 25 KTS AT TIMES.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KFFC 231539
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1139 AM EDT THU MAY 23 2013
.UPDATE...
OVERALL...FORECAST LOOKS TO BE ON TRACK...WITH SLIGHT CHANCE POPS
ACROSS FAR EASTERN GEORGIA AND PARTLY CLOUDY CONDITIONS ACROSS A
LARGE PORTION OF THE AREA. HOURLY FORECAST TRENDS LOOK GOOD FOR
TEMPERATURES AND DEWPOINTS...AND HAVE MADE VERY MINOR ADJUSTMENTS
THROUGH THE DAY. HIGH TEMPERATURES STILL LOOKS TO BE ON TRACK.
SLIGHT CHANCE POPS CONTINUE ACROSS NORTHEAST AND FAR NORTHERN
GEORGIA THROUGH THE AFTERNOON AND EVENING AS MOISTURE RETURNS TO
THE AREA AS LOW PRESSURE TROUGH SWEEPS THROUGH THE OHIO VALLEY.
NO ADDITIONAL UPDATES ARE PLANNED AT THIS TIME.
31
&&
.PREV DISCUSSION... /ISSUED 740 AM EDT THU MAY 23 2013/
SHORT TERM /TODAY THROUGH FRIDAY/...
UPPER LEVEL TROUGH MOVING THROUGH EASTERN SECTIONS OF GA INTO THE
CAROLINAS THIS MORNING. SHOWERS AND THUNDERSTORMS HAVE BEEN
DIMINISHING OVER EASTERN GA AND SHOULD CONTINUE TO DO SO. SOME
LINGERING DYNAMICS MAY SUPPORT SOME CONVECTION MAINLY ALONG THE
EASTERN SIDE OF THE CWA THIS MORNING AND HAVE CONTINUED WITH LOW
POPS FOR THAT AREA. DRIER AIR WILL SPREAD INTO THE CWA TODAY BEHIND
THE SHORT WAVE. HOWEVER...NORTH GA WILL BE ON THE SOUTHERN FRINGES
OF AN UPPER TROUGH DEEPENING INTO THE OHIO AND TENNESSEE VALLEYS
THIS AFTERNOON AND EVENING. SO...HAVE LEFT LOW POPS ACROSS THE
EXTREME NORTHERN COUNTIES THIS AFTERNOON UNTIL AROUND 06Z. OTHERWISE
STRONG NORTHWESTERLY FLOW BRINGING LOWER DEW POINTS AND MORE STABLE
AIR FOR THE REMAINDER OF THE SHORT TERM. NORTHWEST WINDS BECOMING
GUSTY TODAY BUT SHOULD STAY BELOW ADVISORY CRITERIA. SOMEWHAT COOLER
TEMPERATURES IN STORE TONIGHT AND FRIDAY. MAV/MET NUMBERS WERE CLOSE
AND ONLY MINOR TWEAKS WERE MADE.
41
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DRY WEATHER IS EXPECTED TO CONTINUE ACROSS THE AREA THROUGH SUNDAY
AND FOR THE MOST PART BASED ON THE GFS...THROUGH THURSDAY.
HOWEVER THE EUROPEAN MODEL IS INDICATING A WETTER NW FLOW ALOFT
ACROSS N AND PARTS OF CENTRAL GA STARTING SUNDAY NIGHT WITH A
WEAKER UPPER RIDGE AND GREATER POTENTIAL FOR SHORT WAVES TO AFFECT
THE AREA. CURRENT FORECAST HAS LOW POPS ACROSS N GA ON MONDAY AND
TUESDAY AND WILL JUST CONTINUE THAT FORECAST FOR NOW AS A
COMPROMISE. NO INSTABILITY TO SPEAK OFF UNTIL TUESDAY AFTERNOON
WHERE THERE MIGHT BE ENOUGH FOR THUNDERSTORMS OVER FAR N GA. UPPER
RIDGE OVER THE AREA FOR WEDNESDAY INTO THURSDAY. KEEPING POPS NIL
FOR WEDNESDAY EXCEPT FOR LOW POPS OVER THE NE MOUNTAINS WHERE
SOUTHERLY FLOW AND SOME INSTABILITY COULD CAUSE AFTERNOON SHOWERS
AND STORMS.
TEMPERATURES GENERALLY RUNNING WITHIN 6 DEGREES OF NORMAL THROUGH
THE PERIOD EXCEPT SATURDAY MORNING LOWS ARE RUNNING ABOUT 10-15
DEGREES BELOW NORMAL AND SUNDAY MORNING LOWS RUNNING ABOUT 6-12
DEGREES BELOW NORMAL.
BDL
AVIATION...
12Z UPDATE...
EXPECT VFR TODAY...AFTER SOME MVFR AND IFR FOG HAS BURNED OFF BY
14Z. ONLY ISOLATED CONVECTION MAINLY NORTH AND EAST OF TAF SITES
TODAY. WINDS WILL BECOME NORTHWEST 10-15KT AFTER WITH GUSTS OF
20-25KT EXPECTED THROUGH THE AFTERNOON.
//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 86 58 80 46 / 20 5 0 0
ATLANTA 84 59 76 50 / 10 0 0 0
BLAIRSVILLE 79 53 73 40 / 20 20 0 0
CARTERSVILLE 85 56 77 44 / 10 5 0 0
COLUMBUS 87 63 84 55 / 10 0 0 0
GAINESVILLE 83 58 79 48 / 20 10 0 0
MACON 88 59 83 48 / 10 0 0 0
ROME 85 56 78 46 / 10 10 0 0
PEACHTREE CITY 84 56 78 46 / 10 0 0 0
VIDALIA 88 65 87 56 / 20 0 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....01
AVIATION...31
000
FXUS62 KCHS 231517
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1117 AM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATE TONIGHT...WITH DRY
HIGH PRESSURE BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE DISTINCT SHORTWAVE PROGRESSING TOWARD THE FORECAST AREA FROM
THE WEST IS EVIDENT IN WATER VAPOR IMAGERY AS A NOTABLE BOUNDARY
BETWEEN DEEP MOISTURE OVER SOUTH CAROLINA/GEORGIA COASTAL AREAS
AND DRIER AIR FURTHER UPSTATE AND INLAND. THE MAIN COLD FRONT
ASSOCIATED WITH THE UPPER TROUGH AXIS IN THE OHIO VALLEY WILL
REMAIN TO THE NORTHWEST THROUGH THE DAYTIME HOURS...HOWEVER A PRE
FRONTAL TROUGH SEEN IN LATEST MESOANALYSIS WILL PROVIDE SOME
ADDITIONAL CONVERGENCE COINCIDENT WITH THE TIMING OF THE SHORTWAVE
ENERGY THIS AFTERNOON. THE ORIENTATION AND MOVEMENT OF THE
SURFACE TROUGH WILL SUPPORT MORE SOLID DOWNSLOPE FLOW ACROSS THE
GEORGIA COUNTIES...WHILE SOUTH CAROLINA ZONES REMAIN WITHIN A MORE
SOUTHWEST FLOW FOR THE NEXT SEVERAL HOURS. THE DOWNSLOPE FLOW
ACROSS SOUTHERN LOCATIONS COULD LIMIT CONVECTIVE DEVELOPMENT LATER
TODAY.
RADAR TRENDS CONFIRM THAT INITIAL CONVECTIVE DEVELOPMENT WILL
OCCUR ACROSS THE SOUTH CAROLINA ZONES...AS ISOLATED SHOWER
ACTIVITY IS ALREADY TRACKING ACROSS THE CHARLESTON TRI COUNTY
REGION. LATEST THINKING IS THAT SHOWERS/THUNDERSTORMS WILL
INCREASE IN COVERAGE OVER THE TRI COUNTY...WITH ISOLATED
CONVECTION SPREADING SOUTHWARD INTO THE GEORGIA COASTAL ZONES
ALONG THE SEABREEZE. HAVE INDICATED 30 PERCENT RAIN CHANCES IN THE
FAVORED NORTHERN COASTAL AREAS THIS AFTERNOON...WITH SLIGHT
CHANCES INLAND SOUTH CAROLINA AND ALONG THE GEORGIA COASTLINE.
HAVE CAPPED RAIN CHANCES BELOW 15 PERCENT FOR THE INLAND GEORGIA
ZONES WHERE THE AFOREMENTIONED DOWNSLOPE FLOW AND EARLIER
INTRUSION OF DRIER AIR WILL SUPPRESS CONVECTIVE DEVELOPMENT.
MODIFYING THE CHS UPPER AIR SOUNDING FOR AFTERNOON TEMPERATURES
AND DEWPOINTS REVEALS ONLY MARGINAL INSTABILITY...AND WITH
CONTINUED WEAK LAPSE RATES AND WIND PROFILES...SEVERE POTENTIAL IS
LOW AGAIN TODAY.
STRATOCUMULUS QUICKLY DEVELOPED ACROSS SOUTH CENTRAL GEORGIA AND
IS SHIFTING INTO THE CLEAR AREAS OF SOUTHEAST GEORGIA BY MID
MORNING. AS A RESULT...MOST OF THE FORECAST AREA WILL REMAIN
PARTLY CLOUDY TO MOSTLY CLOUDY THROUGHOUT THE AFTERNOON
HOURS...WITH THICKEST SKY COVER ACROSS THE NORTHERN ZONES. CURRENT
FORECAST TEMPERATURES ARE IN DECENT AGREEMENT WITH LATEST
TEMPERATURES...AND WILL THUS MAINTAIN ONGOING FORECAST HIGHS
RANGING FROM THE UPPER 80S INLAND TO THE LOW TO MID 80S ALONG THE
COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THE COLD FRONT WILL MOVE THROUGH SHORTLY AFTER MIDNIGHT TONIGHT
WITH SLIGHTLY DRIER AIR BEGINNING TO FILTER INTO THE REGION.
MOSTLY CLEAR SKIES EXPECTED WITH TEMPERATURES IN THE LOWER 60S.
FRIDAY AND FRIDAY NIGHT...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE
MID-ATLANTIC REGION ON FRIDAY. IN WAKE OF THE DEPARTING COLD
FRONT...A DEEP LAYERED NORTHWEST FLOW WILL PREVAIL THROUGH MUCH OF
THE DAY. THE DOWNSLOPE FLOW WILL RESULT IN DRYING ACROSS THE AREA
AND WILL ALSO NEGATE MOST OF THE INITIAL SURGE OF COLD AIR ADVECTION
AS HIGHS SHOULD STILL BE IN THE MID TO UPPER 80S. UNDER MOSTLY SUNNY
SKIES...BREEZY CONDITIONS ARE ALSO EXPECTED. THEN...AS THE UPPER
TROUGH PASSES OFF THE MID-ATLANTIC COAST FRIDAY EVENING...IT WILL
PUSH A SECONDARY COLD FRONT ACROSS THE AREA ALLOWING HIGH PRESSURE
TO BUILD FROM THE GREAT LAKES REGION. THE AIR MASS WILL BEGIN TO
MODIFY SIGNIFICANTLY FOLLOWING THE SECONDARY COLD FRONT WITH
TEMPERATURES PLUMMETING INTO THE UPPER 40S AND LOWER 50S FRIDAY
NIGHT ON A NORTHERLY FLOW.
SATURDAY AND SATURDAY NIGHT...A VERY DRY AIR MASS WILL SETTLE OVER
THE REGION SATURDAY AS HIGH PRESSURE CONTINUES TO BUILD IN FROM THE
GREAT LAKES REGION. PRECIPITABLE WATER VALUES OF .25 TO .40 INCHES
WILL BE ABOUT AS LOW AS THEY CAN GET FOR THIS TIME OF YEAR...OR MORE
THAN 2 STANDARD DEVIATIONS BELOW NORMAL. FORECAST THICKNESS VALUES
ONLY SUPPORT HIGHS IN THE MID TO UPPER 70S...BUT GIVEN FULL SUNSHINE
AND THE HIGHER SUN ANGLE THIS TIME OF YEAR...WILL INDICATE HIGHS IN
THE UPPER 70S TO LOWER 80S ACROSS THE AREA. ANOTHER UNSEASONABLY
COOL NIGHT IS EXPECTED SATURDAY NIGHT...WITH LOWS IN THE LOWER TO
MID 50S.
SUNDAY...A WEAK PRESSURE PATTERN WILL PREVAIL OVER THE REGION. AN
INCREASE IN MID AND HIGH LEVEL MOISTURE WILL SUPPORT SOME CLOUD
COVER BUT THE AIR MASS IS TOO DRY STILL FOR ANY SHOWERS TO DEVELOP.
HIGHS SHOULD BE IN THE LOWER TO MID 80S ACROSS MUCH OF THE AREA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE REGION WILL BE SANDWICHED BETWEEN TWO AREAS OF HIGH PRESSURE
EARLY IN THE WEEK...THE STRONGER OF THE TWO PASSING ACROSS THE
MID-ATLANTIC REGION AND THE OTHER OVER THE NORTHEAST GULF OF MEXICO.
DEEPENING MOISTURE WILL RESULT IN AT LEAST AN INCREASE IN CLOUD
COVER...BUT IT APPEARS THE RAIN-FREE CONDITIONS SHOULD PERSIST
THROUGH MEMORIAL DAY. ATLANTIC HIGH PRESSURE WILL THEN BECOME
ESTABLISHED THROUGH THE MIDDLE OF NEXT WEEK...SUPPORTING MAINLY
DIURNAL ISOLATED CONVECTION EACH AFTERNOON ALONG AND AHEAD OF THE
SEA BREEZE TUESDAY THROUGH THURSDAY. TEMPERATURES WILL MODERATE TO
NEAR NORMAL BY EARLY NEXT WEEK AND CONTINUE NEAR SEASONAL NORMS
THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT BOTH KCHS AND KSAV
THROUGH 12Z FRIDAY. SCATTERED SHOWERS HAVE ALREADY DEVELOPED IN
ASSOCIATION WITH A PRE-FRONTAL TROUGH ACROSS SOUTHEAST SOUTH
CAROLINA. HAVE KEPT MENTION OF ANY PRECIPITATION OUT OF THE KSAV
TAF SINCE COVERAGE WILL BE LIMITED ACROSS SOUTHEAST GEORGIA. ANY
CEILINGS WILL REMAIN VFR OUTSIDE OF CONVECTION...WITH CLEARING
EXPECTED TONIGHT.
EXTENDED AVIATION...VFR CONDITIONS WILL PREVAIL. GUSTY WINDS ARE
POSSIBLE FRIDAY AFTERNOON.
&&
.MARINE...
WINDS AND SEAS WILL BE FAIRLY BENIGN TODAY...BEFORE WINDS
INCREASE OUT OF THE SOUTHWEST AND WEST TONIGHT AS A COLD FRONT
PUSHES THROUGH THE WATERS. WIND SPEEDS WILL INCREASE TO AROUND 15
KT...YET THE OFFSHORE FETCH WILL LIMIT THE BUILDING OF SEAS TO NO
HIGHER THAN 4 FT.
FRIDAY THROUGH TUESDAY...A NORTHWEST FLOW WILL DEVELOP ON FRIDAY IN
WAKE OF A DEPARTING COLD FRONT. A SECONDARY COLD FRONT WILL THEN
MOVE THROUGH BY FRIDAY EVENING...WITH A STRONGER NORTHERLY SURGE
DEVELOPING IN ITS WAKE FRIDAY NIGHT INTO EARLY SATURDAY...POSSIBLY
RESULTING IN SMALL CRAFT ADVISORY CONDITIONS OVER A PORTION OF THE
WATERS.
CONDITIONS WILL THEN IMPROVE LATER IN THE WEEKEND WITH WINDS/SEAS
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH
EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WMS
SHORT TERM...JAQ/JRL
LONG TERM...JAQ
AVIATION...JAQ
MARINE...JAQ/JRL
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 231439
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1039 AM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE AND INSTABILITY AHEAD OF A MID-LEVEL SHORTWAVE TROUGH
WAS SUPPORTING SCATTERED SHOWERS EARLY THIS MORNING. SATELLITE
TRENDS AND THE MODELS INDICATE DEEPER MOISTURE ASSOCIATED WITH
THE SHORTWAVE TROUGH WILL SHIFT EAST OF THE FORECAST AREA EARLY
THIS AFTERNOON. A PRE-FRONTAL TROUGH WILL BE IN THE FORECAST AREA
THROUGH TODAY. CONVERGENCE ASSOCIATED WITH THIS FEATURE PLUS
DIURNAL HEATING SHOULD SUPPORT THUNDERSTORMS BUT EXPECT LIMITED
COVERAGE BECAUSE OF DIMINISHED MOISTURE BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS AFTERNOON. MAINTAINED CHANCE POPS WITH
THE GREATER VALUES IN THE NORTHEAST PART CLOSER TO THE DEEPER
MOISTURE AND MORE CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH.
BASICALLY HAVE 20-30 PERCENT CHANCE WEST AND 30-50 PERCENT CHANCE
EAST WITH AROUND 50 PERCENT CHANCE IN THE NORTHEAST PART. MODERATE
INSTABILITY MAY SUPPORT DAMAGING WIND WITH A FEW OF THE
THUNDERSTORMS. WET-BULB ZERO HEIGHTS ALSO SUPPORT HAIL. THE
TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY SUPPORT
THUNDERSTORMS EARLY. COVERAGE SHOULD STILL BE LIMITED WITH DEEPER
MOISTURE EAST OF THE AREA. DRYING BEHIND THE FRONT SHOULD DOMINATE
LATE TONIGHT THROUGH FRIDAY NIGHT. MIXING ASSOCIATED WITH THE
FRONT SUPPORTED THE WARMER TEMPERATURE GUIDANCE TONIGHT. WE WILL
GET OFF TO A RELATIVELY WARM START SO THE WARMER GUIDANCE APPEARED
BETTER FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FRIDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. EXPECT SOME INCREASE IN MOISTURE BEGINNING MONDAY. THE
GFS AND ECMWF DISPLAY A WARM FRONT DEVELOPING NEAR THE AREA. THE
GFS IS FARTHER NORTHWARD WITH THE PLACEMENT OF THE FRONT. THE GFS
ALSO SHOWS LESS MOISTURE IN THE FORECAST AREA. BOTH MODELS SHOW
AN INCREASE IN H5 RIDGING WHICH SHOULD LIMIT THUNDERSTORMS.
BELIEVE THE BEST FORECAST FOR NOW IS AN AVERAGE OF THE GFS AND
ECMWF MOS. FORECASTED SLIGHT CHANCE POPS TUESDAY AND WEDNESDAY.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
EARLY MORNING CONVECTION AS NEARLY DIMINISHED ACROSS THE CWA THIS
MORNING. SOME MVFR CIGS WILL LINGER UNTIL AROUND 14Z. UPPER IMPULSE
AND SURFACE TROUGH WILL MOVE THROUGH THIS AFTERNOON...POSSIBLY
LEADING TO SCT SHRA/TSRA. BEST CHANCE APPEARS TO BE NORTH/EAST OF
MOST TAF SITES. DUE TO THE SCATTERED NATURE OF THE CONVECTION...WILL
NOT MENTION PRECIPITATION AT ANY OF THE TAF SITES FOR THE AFTERNOON
HOURS. BY LATER THIS EVENING...SKIES SHOULD BEGIN TO CLEAR AS DRIER
AIR MOVES INTO THE AREA FROM THE WEST.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCAE 231313
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
913 AM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE AND INSTABILITY AHEAD OF A MID-LEVEL SHORTWAVE TROUGH
WAS SUPPORTING SCATTERED SHOWERS EARLY THIS MORNING. SATELLITE
TRENDS AND THE MODELS INDICATE DEEPER MOISTURE ASSOCIATED WITH
THE SHORTWAVE TROUGH WILL SHIFT EAST OF THE FORECAST AREA EARLY
THIS AFTERNOON. A PRE-FRONTAL TROUGH WILL BE IN THE FORECAST AREA
THROUGH TODAY. CONVERGENCE ASSOCIATED WITH THIS FEATURE PLUS
DIURNAL HEATING SHOULD SUPPORT THUNDERSTORMS BUT EXPECT LIMITED
COVERAGE BECAUSE OF DIMINISHED MOISTURE BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS AFTERNOON. MAINTAINED CHANCE POPS WITH
THE GREATER VALUES IN THE NORTHEAST PART CLOSER TO THE DEEPER
MOISTURE AND MORE CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH.
MODERATE INSTABILITY MAY SUPPORT DAMAGING WIND WITH A FEW OF THE
THUNDERSTORMS. WET-BULB ZERO HEIGHTS ALSO SUPPORT HAIL. THE
TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY SUPPORT
THUNDERSTORMS EARLY. COVERAGE SHOULD STILL BE LIMITED WITH DEEPER
MOISTURE EAST OF THE AREA. DRYING BEHIND THE FRONT SHOULD DOMINATE
LATE TONIGHT THROUGH FRIDAY NIGHT. MIXING ASSOCIATED WITH THE
FRONT SUPPORTED THE WARMER TEMPERATURE GUIDANCE TONIGHT. WE WILL
GET OFF TO A RELATIVELY WARM START SO THE WARMER GUIDANCE APPEARED
BETTER FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FRIDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. EXPECT SOME INCREASE IN MOISTURE BEGINNING MONDAY. THE
GFS AND ECMWF DISPLAY A WARM FRONT DEVELOPING NEAR THE AREA. THE
GFS IS FARTHER NORTHWARD WITH THE PLACEMENT OF THE FRONT. THE GFS
ALSO SHOWS LESS MOISTURE IN THE FORECAST AREA. BOTH MODELS SHOW
AN INCREASE IN H5 RIDGING WHICH SHOULD LIMIT THUNDERSTORMS.
BELIEVE THE BEST FORECAST FOR NOW IS AN AVERAGE OF THE GFS AND
ECMWF MOS. FORECASTED SLIGHT CHANCE POPS TUESDAY AND WEDNESDAY.
&&
.AVIATION /13Z THURSDAY THROUGH TUESDAY/...
EARLY MORNING CONVECTION AS NEARLY DIMINISHED ACROSS THE CWA THIS
MORNING. SOME MVFR CIGS WILL LINGER UNTIL AROUND 14Z. UPPER IMPULSE
AND SURFACE TROUGH WILL MOVE THROUGH THIS AFTERNOON...POSSIBLY
LEADING TO SCT SHRA/TSRA. BEST CHANCE APPEARS TO BE NORTH/EAST OF
MOST TAF SITES. DUE TO THE SCATTERED NATURE OF THE CONVECTION...WILL
NOT MENTION PRECIPITATION AT ANY OF THE TAF SITES FOR THE AFTERNOON
HOURS. BY LATER THIS EVENING...SKIES SHOULD BEGIN TO CLEAR AS DRIER
AIR MOVES INTO THE AREA FROM THE WEST.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 231155
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
755 AM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH LATE TONIGHT WITH DRY HIGH PRESSURE
BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RAIN SHOWERS ASSOCIATED WITH A WELL DEFINED SHORTWAVE DISTURBANCE
MOVING ACROSS EASTERN GEORGIA AND THE UPSTATE OF SOUTH CAROLINA
HAVE GENERALLY DISSIPATED THIS MORNING DURING WHAT IS TYPICALLY A
CLIMATOLOGICAL MINIMUM FOR CONVECTION.
THE PRIMARY SHORTWAVE WILL PROGRESS THROUGH THE AREA FROM WEST TO
EAST TODAY. BY EARLY AFTERNOON IT LOOKS AS THOUGH VEERING WINDS ACROSS
SOUTHEAST GA WILL PRODUCE SOME DOWNSLOPE FLOW AND ALLOW FOR
PARTIAL CLEARING WITH TEMPS PUSHING INTO THE UPPER 80S. IN
SOUTHERN SC A DECENT SEABREEZE SHOULD TAKE SHAPE EARLY TO MID
AFTERNOON AND INTERACT WITH THE RESIDUAL SHORTWAVE ENERGY. WITH
DECENT SURFACE BASED CAPES AND COOLING MID-LEVELS THERE SHOULD BE
SCATTERED COVERAGE OF SHOWERS AND TSTMS MAINLY IN SOUTHERN SC THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THE COLD FRONT WILL MOVE THROUGH SHORTLY AFTER MIDNIGHT TONIGHT
WITH SLIGHTLY DRIER AIR BEGINNING TO FILTER IN. MOSTLY CLEAR SKIES
EXPECTED WITH TEMPERATURES IN THE LOWER 60S.
FRIDAY AND FRIDAY NIGHT...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE
MID-ATLANTIC REGION ON FRIDAY. IN WAKE OF THE DEPARTING COLD
FRONT...A DEEP LAYERED NORTHWEST FLOW WILL PREVAIL THROUGH MUCH OF
THE DAY. THE DOWNSLOPE FLOW WILL RESULT IN DRYING ACROSS THE AREA
AND WILL ALSO NEGATE MOST OF THE INITIAL SURGE OF COLD AIR ADVECTION
AS HIGHS SHOULD STILL BE IN THE MID TO UPPER 80S. UNDER MOSTLY SUNNY
SKIES...BREEZY CONDITIONS ARE ALSO EXPECTED. THEN...AS THE UPPER
TROUGH PASSES OFF THE MID-ATLANTIC COAST FRIDAY EVENING...IT WILL
PUSH A SECONDARY COLD FRONT ACROSS THE AREA ALLOWING HIGH PRESSURE
TO BUILD FROM THE GREAT LAKES REGION. THE AIRMASS WILL BEGIN TO
MODIFY SIGNIFICANTLY FOLLOWING THE SECONDARY COLD FRONT WITH
TEMPERATURES PLUMMETING INTO THE UPPER 40S AND LOWER 50S FRIDAY
NIGHT ON A NORTHERLY FLOW.
SATURDAY AND SATURDAY NIGHT...A VERY DRY AIRMASS WILL SETTLE OVER
THE REGION SATURDAY AS HIGH PRESSURE CONTINUES TO BUILD IN FROM THE
GREAT LAKES REGION. PRECIPITABLE WATER VALUES OF .25 TO .40 INCHES
WILL BE ABOUT AS LOW AS THEY CAN GET FOR THIS TIME OF YEAR...OR MORE
THAN 2 STANDARD DEVIATIONS BELOW NORMAL. FORECAST THICKNESS VALUES
ONLY SUPPORT HIGHS IN THE MID TO UPPER 70S...BUT GIVEN FULL SUNSHINE
AND THE HIGHER SUN ANGLE THIS TIME OF YEAR...WILL INDICATE HIGHS IN
THE UPPER 70S TO LOWER 80S ACROSS THE AREA. ANOTHER UNSEASONABLY
COOL NIGHT IS EXPECTED SATURDAY NIGHT...WITH LOWS IN THE LOWER TO
MID 50S.
SUNDAY...A WEAK PRESSURE PATTERN WILL PREVAIL OVER THE REGION. AN
INCREASE IN MID AND HIGH LEVEL MOISTURE WILL SUPPORT SOME CLOUD
COVER BUT THE AIRMASS IS TOO DRY STILL FOR ANY SHOWERS TO DEVELOP.
HIGHS SHOULD BE IN THE LOWER TO MID 80S ACROSS MUCH OF THE AREA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE REGION WILL BE SANDWICHED BETWEEN TWO AREAS OF HIGH PRESSURE
EARLY IN THE WEEK...THE STRONGER OF THE TWO PASSING ACROSS THE
MID-ATLANTIC REGION AND THE OTHER OVER THE NORTHEAST GULF OF MEXICO.
DEEPENING MOISTURE WILL RESULT IN AT LEAST AN INCREASE IN CLOUD
COVER...BUT IT APPEARS THE RAIN-FREE CONDITIONS SHOULD PERSIST
THROUGH MEMORIAL DAY. ATLANTIC HIGH PRESSURE WILL THEN BECOME
ESTABLISHED THROUGH THE MIDDLE OF NEXT WEEK...SUPPORTING MAINLY
DIURNAL ISOLATED CONVECTION EACH AFTERNOON ALONG AND AHEAD OF THE
SEA BREEZE TUESDAY THROUGH THURSDAY. TEMPERATURES WILL MODERATE TO
NEAR NORMAL BY EARLY NEXT WEEK AND CONTINUE NEAR SEASONAL NORMS
THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT BOTH KCHS AND KSAV
THROUGH 12Z FRIDAY. SCATTERED SHOWERS SHOULD DEVELOP IN ASSOCIATION
WITH A PRE-FRONTAL TROUGH ACROSS SOUTHEAST SC THIS AFTERNOON...WITH
COVERAGE MORE ISOLATED ELSEWHERE. AS A RESULT...VICINITY SHOWERS
ARE INCLUDED IN THE KCHS TAF FROM 16-22Z UNTIL CONFIDENCE IN
TIMING/COVERAGE IMPROVES. HAVE KEPT MENTION OF ANY PRECIPITATION
OUT OF THE KSAV TAF SINCE COVERAGE WILL BE LIMITED ACROSS
SOUTHEAST GA. ANY CEILINGS WILL REMAIN VFR OUTSIDE OF
CONVECTION...WITH CLEARING EXPECTED TONIGHT.
EXTENDED AVIATION...VFR CONDITIONS WILL PREVAIL. GUSTY WINDS ARE
POSSIBLE FRIDAY AFTERNOON.
&&
.MARINE...
WINDS/SEAS WILL BE FAIRLY LOW THROUGH TODAY...THEN WINDS INCREASE
OUT OF THE SW AND W TONIGHT AS A COLD FRONT PUSHES THROUGH THE
WATERS. WIND SPEEDS WILL TOP OUT AROUND 15 KT BUT THE OFFSHORE
FETCH WILL LIMIT THE BUILDING OF SEAS TO NO HIGHER THAN 4 FT.
FRIDAY THROUGH TUESDAY...A NORTHWEST FLOW WILL DEVELOP ON FRIDAY IN
WAKE OF A DEPARTING COLD FRONT. A SECONDARY COLD FRONT WILL THEN
MOVE THROUGH BY FRIDAY EVENING...WITH A STRONGER NORTHERLY SURGE
DEVELOPING IN ITS WAKE FRIDAY NIGHT INTO EARLY SATURDAY...POSSIBLY
RESULTING IN SMALL CRAFT ADVISORY CONDITIONS OVER A PORTION OF THE
WATERS.
CONDITIONS WILL THEN IMPROVE LATER IN THE WEEKEND WITH WINDS/SEAS
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH
EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JRL/JAQ
SHORT TERM...JRL/JAQ
LONG TERM...JAQ
AVIATION...JAQ
MARINE...JRL/JAQ
TIDES/COASTAL FLOODING...
000
FXUS62 KFFC 231141
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
740 AM EDT THU MAY 23 2013
.SHORT TERM /TODAY THROUGH FRIDAY/...
UPPER LEVEL TROUGH MOVING THROUGH EASTERN SECTIONS OF GA INTO THE
CAROLINAS THIS MORNING. SHOWERS AND THUNDERSTORMS HAVE BEEN
DIMINISHING OVER EASTERN GA AND SHOULD CONTINUE TO DO SO. SOME
LINGERING DYNAMICS MAY SUPPORT SOME CONVECTION MAINLY ALONG THE
EASTERN SIDE OF THE CWA THIS MORNING AND HAVE CONTINUED WITH LOW
POPS FOR THAT AREA. DRIER AIR WILL SPREAD INTO THE CWA TODAY BEHIND
THE SHORT WAVE. HOWEVER...NORTH GA WILL BE ON THE SOUTHERN FRINGES
OF AN UPPER TROUGH DEEPENING INTO THE OHIO AND TENNESSEE VALLEYS
THIS AFTERNOON AND EVENING. SO...HAVE LEFT LOW POPS ACROSS THE
EXTREME NORTHERN COUNTIES THIS AFTERNOON UNTIL AROUND 06Z. OTHERWISE
STRONG NORTHWESTERLY FLOW BRINGING LOWER DEW POINTS AND MORE STABLE
AIR FOR THE REMAINDER OF THE SHORT TERM. NORTHWEST WINDS BECOMING
GUSTY TODAY BUT SHOULD STAY BELOW ADVISORY CRITERIA. SOMEWHAT COOLER
TEMPERATURES IN STORE TONIGHT AND FRIDAY. MAV/MET NUMBERS WERE CLOSE
AND ONLY MINOR TWEAKS WERE MADE.
41
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DRY WEATHER IS EXPECTED TO CONTINUE ACROSS THE AREA THROUGH SUNDAY
AND FOR THE MOST PART BASED ON THE GFS...THROUGH THURSDAY.
HOWEVER THE EUROPEAN MODEL IS INDICATING A WETTER NW FLOW ALOFT
ACROSS N AND PARTS OF CENTRAL GA STARTING SUNDAY NIGHT WITH A
WEAKER UPPER RIDGE AND GREATER POTENTIAL FOR SHORT WAVES TO AFFECT
THE AREA. CURRENT FORECAST HAS LOW POPS ACROSS N GA ON MONDAY AND
TUESDAY AND WILL JUST CONTINUE THAT FORECAST FOR NOW AS A
COMPROMISE. NO INSTABILITY TO SPEAK OFF UNTIL TUESDAY AFTERNOON
WHERE THERE MIGHT BE ENOUGH FOR THUNDERSTORMS OVER FAR N GA. UPPER
RIDGE OVER THE AREA FOR WEDNESDAY INTO THURSDAY. KEEPING POPS NIL
FOR WEDNESDAY EXCEPT FOR LOW POPS OVER THE NE MOUNTAINS WHERE
SOUTHERLY FLOW AND SOME INSTABILITY COULD CAUSE AFTERNOON SHOWERS
AND STORMS.
TEMPERATURES GENERALLY RUNNING WITHIN 6 DEGREES OF NORMAL THROUGH
THE PERIOD EXCEPT SATURDAY MORNING LOWS ARE RUNNING ABOUT 10-15
DEGREES BELOW NORMAL AND SUNDAY MORNING LOWS RUNNING ABOUT 6-12
DEGREES BELOW NORMAL.
BDL
&&
.AVIATION...
12Z UPDATE...
EXPECT VFR TODAY...AFTER SOME MVFR AND IFR FOG HAS BURNED OFF BY
14Z. ONLY ISOLATED CONVECTION MAINLY NORTH AND EAST OF TAF SITES
TODAY. WINDS WILL BECOME NORTHWEST 10-15KT AFTER WITH GUSTS OF
20-25KT EXPECTED THROUGH THE AFTERNOON.
//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 86 58 80 46 / 20 5 0 0
ATLANTA 84 59 76 50 / 10 0 0 0
BLAIRSVILLE 79 53 73 40 / 20 20 0 0
CARTERSVILLE 85 56 77 44 / 10 5 0 0
COLUMBUS 87 63 84 55 / 10 0 0 0
GAINESVILLE 83 58 79 48 / 20 10 0 0
MACON 88 59 83 48 / 10 0 0 0
ROME 85 56 78 46 / 10 10 0 0
PEACHTREE CITY 84 56 78 46 / 10 0 0 0
VIDALIA 88 65 87 56 / 20 0 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41
LONG TERM....BDL
AVIATION...41
000
FXUS62 KCAE 231022
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
622 AM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE AND INSTABILITY AHEAD OF A MID-LEVEL SHORTWAVE TROUGH
WAS SUPPORTING SCATTERED SHOWERS EARLY THIS MORNING. SATELLITE
TRENDS AND THE MODELS INDICATE DEEPER MOISTURE ASSOCIATED WITH
THE SHORTWAVE TROUGH WILL SHIFT EAST OF THE FORECAST AREA EARLY
THIS AFTERNOON. A PRE-FRONTAL TROUGH WILL BE IN THE FORECAST AREA
THROUGH TODAY. CONVERGENCE ASSOCIATED WITH THIS FEATURE PLUS
DIURNAL HEATING SHOULD SUPPORT THUNDERSTORMS BUT EXPECT LIMITED
COVERAGE BECAUSE OF DIMINISHED MOISTURE BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS AFTERNOON. MAINTAINED CHANCE POPS WITH
THE GREATER VALUES IN THE NORTHEAST PART CLOSER TO THE DEEPER
MOISTURE AND MORE CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH.
MODERATE INSTABILITY MAY SUPPORT DAMAGING WIND WITH A FEW OF THE
THUNDERSTORMS. WET-BULB ZERO HEIGHTS ALSO SUPPORT HAIL. THE
TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY SUPPORT
THUNDERSTORMS EARLY. COVERAGE SHOULD STILL BE LIMITED WITH DEEPER
MOISTURE EAST OF THE AREA. DRYING BEHIND THE FRONT SHOULD DOMINATE
LATE TONIGHT THROUGH FRIDAY NIGHT. MIXING ASSOCIATED WITH THE
FRONT SUPPORTED THE WARMER TEMPERATURE GUIDANCE TONIGHT. WE WILL
GET OFF TO A RELATIVELY WARM START SO THE WARMER GUIDANCE APPEARED
BETTER FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FRIDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. EXPECT SOME INCREASE IN MOISTURE BEGINNING MONDAY. THE
GFS AND ECMWF DISPLAY A WARM FRONT DEVELOPING NEAR THE AREA. THE
GFS IS FARTHER NORTHWARD WITH THE PLACEMENT OF THE FRONT. THE GFS
ALSO SHOWS LESS MOISTURE IN THE FORECAST AREA. BOTH MODELS SHOW
AN INCREASE IN H5 RIDGING WHICH SHOULD LIMIT THUNDERSTORMS.
BELIEVE THE BEST FORECAST FOR NOW IS AN AVERAGE OF THE GFS AND
ECMWF MOS. FORECASTED SLIGHT CHANCE POPS TUESDAY AND WEDNESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH TUESDAY/...
CONVECTION CONTINUES TO DIMINISH AS IT MOVES ENE ACROSS THE AREA.
SHOWERS SHOULD END BY AROUND 12Z-13Z. SOME IFR/MVFR CIGS WILL LINGER
UNTIL AROUND 13Z. UPPER IMPULSE AND SURFACE TROUGH WILL MOVE THROUGH
LATER TODAY...POSSIBLY LEADING TO SCT SHRA/TSRA. DUE TO THE
SCATTERED NATURE OF THE CONVECTION...WILL NOT MENTION PRECIPITATION
AT ANY OF THE TAF SITES FOR THE AFTERNOON HOURS. BY LATE THIS
EVENING...SKIES SHOULD BEGIN TO CLEAR AS DRIER AIR MOVES INTO THE
AREA FROM THE WEST.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCAE 231007
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
607 AM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE AND INSTABILITY AHEAD OF A MID-LEVEL SHORTWAVE TROUGH
WAS SUPPORTING SCATTERED SHOWERS EARLY THIS MORNING. SATELLITE
TRENDS AND THE MODELS INDICATE DEEPER MOISTURE ASSOCIATED WITH
THE SHORTWAVE TROUGH WILL SHIFT EAST OF THE FORECAST AREA EARLY
THIS AFTERNOON. A PRE-FRONTAL TROUGH WILL BE IN THE FORECAST AREA
THROUGH TODAY. CONVERGENCE ASSOCIATED WITH THIS FEATURE PLUS
DIURNAL HEATING SHOULD SUPPORT THUNDERSTORMS BUT EXPECT LIMITED
COVERAGE BECAUSE OF DIMINISHED MOISTURE BEHIND THE MID-LEVEL
SHORTWAVE TROUGH THIS AFTERNOON. MAINTAINED CHANCE POPS WITH
THE GREATER VALUES IN THE NORTHEAST PART CLOSER TO THE DEEPER
MOISTURE AND MORE CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH.
MODERATE INSTABILITY MAY SUPPORT DAMAGING WIND WITH A FEW OF THE
THUNDERSTORMS. WET-BULB ZERO HEIGHTS ALSO SUPPORT HAIL. THE
TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY SUPPORT
THUNDERSTORMS EARLY. COVERAGE SHOULD STILL BE LIMITED WITH DEEPER
MOISTURE EAST OF THE AREA. DRYING BEHIND THE FRONT SHOULD DOMINATE
LATE TONIGHT THROUGH FRIDAY NIGHT. MIXING ASSOCIATED WITH THE
FRONT SUPPORTED THE WARMER TEMPERATURE GUIDANCE TONIGHT. WE WILL
GET OFF TO A RELATIVELY WARM START SO THE WARMER GUIDANCE APPEARED
BETTER FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FRIDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. EXPECT SOME INCREASE IN MOISTURE BEGINNING MONDAY. THE
GFS AND ECMWF DISPLAY A WARM FRONT DEVELOPING NEAR THE AREA. THE
GFS IS FARTHER NORTHWARD WITH THE PLACEMENT OF THE FRONT. THE GFS
ALSO SHOWS LESS MOISTURE IN THE FORECAST AREA. BOTH MODELS SHOW
AN INCREASE IN H5 RIDGING WHICH SHOULD LIMIT THUNDERSTORMS.
BELIEVE THE BEST FORECAST FOR NOW IS AN AVERAGE OF THE GFS AND
ECMWF MOS. FORECASTED SLIGHT CHANCE POPS TUESDAY AND WEDNESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
CONVECTION CONTINUES TO SLOWLY WEAKEN AS IT MOVES TO THE ENE. MOST
ACTIVITY CURRENTLY CONFINED TO THE UPSTATE SC AND EASTERN GA. HIGH
RES MODELS CONTINUE TO SUGGEST THE ACTIVITY WILL GRADUALLY WEAKEN AS
IT MOVES INTO THE AREA. WILL MENTION A TEMPO GROUP FOR SHOWERS FOR
AGS/DNL UNTIL AROUND 09Z-10Z...AND 10Z-11Z AT CAE/CUB. NOT ENOUGH
CONFIDENCE TO MENTION PRECIP AT OGB AT THIS TIME.
GUIDANCE ALSO CONTINUING TO INDICATE CIG RESTRICTIONS EARLY THIS
MORNING...IN A CONTINUED MOIST SOUTHERLY LOW LEVEL FLOW. FOR
NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL MONITOR LATEST
GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED. UPPER IMPULSE AND
SURFACE TROUGH WILL MOVE THROUGH LATER TODAY...POSSIBLY LEADING TO
SCT SHRA/TSRA. DUE TO THE SCATTERED NATURE OF THE CONVECTION...WILL
NOT MENTION PRECIPITATION AT ANY OF THE TAF SITES FOR THE AFTERNOON
HOURS. BY LATE THIS EVENING...SKIES SHOULD BEGIN TO CLEAR AS DRIER
AIR MOVES INTO THE AREA FROM THE WEST.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCAE 230832
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
431 AM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE AND INSTABILITY AHEAD OF A MID-LEVEL SHORTWAVE TROUGH
WAS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS EARLY THIS
MORNING. SATELLITE TRENDS AND THE MODELS INDICATE DEEPER MOISTURE
ASSOCIATED WITH THIS FEATURE WILL SHIFT EAST OF THE FORECAST AREA
LATER THIS MORNING. A PRE-FRONTAL TROUGH WILL BE IN THE FORECAST
AREA TODAY. CONVERGENCE ASSOCIATED WITH THIS FEATURE PLUS DIURNAL
HEATING SHOULD SUPPORT THUNDERSTORMS BUT EXPECT LIMITED COVERAGE
BECAUSE OF DIMINISHED MOISTURE BEHIND THE MID-LEVEL SHORTWAVE
TROUGH. MAINTAINED CHANCE POPS WITH THE GREATER VALUES IN THE
NORTHEAST PART CLOSER TO DEEPER MOISTURE AND MORE CONVERGENCE
ASSOCIATED WITH THE SURFACE TROUGH. MODERATE INSTABILITY MAY
SUPPORT DAMAGING WIND WITH A FEW OF THE THUNDERSTORMS. WET-BULB
ZERO HEIGHTS ALSO SUPPORT HAIL. THE TEMPERATURE GUIDANCE WAS
CLOSE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY SUPPORT
THUNDERSTORMS EARLY. COVERAGE SHOULD STILL BE LIMITED WITH DEEPER
MOISTURE EAST OF THE AREA. DRYING BEHIND THE FRONT SHOULD DOMINATE
LATE TONIGHT THROUGH FRIDAY NIGHT. MIXING ASSOCIATED WITH THE
FRONT SUPPORTED THE WARMER TEMPERATURE GUIDANCE TONIGHT. WE WILL
GET OFF TO A RELATIVELY WARM START SO THE WARMER GUIDANCE APPEARED
BETTER FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FRIDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. EXPECT SOME INCREASE IN MOISTURE BEGINNING MONDAY. THE
GFS AND ECMWF DISPLAY A WARM FRONT DEVELOPING NEAR THE AREA. THE
GFS IS FARTHER NORTHWARD WITH THE PLACEMENT OF THE FRONT. THE GFS
ALSO SHOWS LESS MOISTURE IN THE FORECAST AREA. BOTH MODELS SHOW
AN INCREASE IN H5 RIDGING WHICH SHOULD LIMIT THUNDERSTORMS.
BELIEVE THE BEST FORECAST FOR NOW IS AN AVERAGE OF THE GFS AND
ECMWF MOS. FORECASTED SLIGHT CHANCE POPS TUESDAY AND WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH TUESDAY/...
CONVECTION CONTINUES TO SLOWLY WEAKEN AS IT MOVES TO THE ENE. MOST
ACTIVITY CURRENTLY CONFINED TO THE UPSTATE SC AND EASTERN GA. HIGH
RES MODELS CONTINUE TO SUGGEST THE ACTIVITY WILL GRADUALLY WEAKEN AS
IT MOVES INTO THE AREA. WILL MENTION A TEMPO GROUP FOR SHOWERS FOR
AGS/DNL UNTIL AROUND 09Z-10Z...AND 10Z-11Z AT CAE/CUB. NOT ENOUGH
CONFIDENCE TO MENTION PRECIP AT OGB AT THIS TIME.
GUIDANCE ALSO CONTINUING TO INDICATE CIG RESTRICTIONS EARLY THIS
MORNING...IN A CONTINUED MOIST SOUTHERLY LOW LEVEL FLOW. FOR
NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL MONITOR LATEST
GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED. UPPER IMPULSE AND
SURFACE TROUGH WILL MOVE THROUGH LATER TODAY...POSSIBLY LEADING TO
SCT SHRA/TSRA. DUE TO THE SCATTERED NATURE OF THE CONVECTION...WILL
NOT MENTION PRECIPITATION AT ANY OF THE TAF SITES FOR THE AFTERNOON
HOURS. BY LATE THIS EVENING...SKIES SHOULD BEGIN TO CLEAR AS DRIER
AIR MOVES INTO THE AREA FROM THE WEST.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 230820
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
420 AM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH LATE TONIGHT WITH DRY HIGH PRESSURE
BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A PRONOUNCED SHORTWAVE DISTURBANCE TREKKING ACROSS EASTERN GA
EARLY THIS MORNING CONTINUES TO DRIVE A WEAKENING BAND OF RAIN
SHOWERS INTO OUR FAR WESTERN ZONES. AS WE MOVE CLOSER TO THE
CLIMATOLOGICAL MINIMUM FOR CONVECTION...THIS ACTIVITY LOOKS LIKE
IT WILL DISSIPATE BEFORE MAKING ITS WAY INTO SOUTHERN SC. WE HAVE
SOME POPS ACROSS SOUTHEAST GA THROUGH DAYBREAK BUT WITH A
DIMINISHING TREND. THE INCREASE IN MID-LEVEL CLOUDINESS IN
CONVECTIVE DEBRIS WILL AT LEAST HELP LIMIT FOG POTENTIAL OVER THE
AREA THIS MORNING.
AFTER DAYBREAK THE PRIMARY VORT WILL PROGRESS THROUGH THE AREA
FROM WEST TO EAST. BY EARLY AFTERNOON IT LOOKS AS THOUGH VEERING
WINDS ACROSS SOUTHEAST GA WILL PRODUCE SOME DOWNSLOPE FLOW AND
ALLOW FOR PARTIAL CLEARING WITH TEMPS PUSHING INTO THE UPPER 80S.
IN SOUTHERN SC A DECENT SEABREEZE SHOULD TAKE SHAPE EARLY TO MID
AFTERNOON AND INTERACT WITH THE RESIDUAL SHORTWAVE ENERGY. WITH
DECENT SURFACE BASED CAPES AND COOLING MID-LEVELS THERE SHOULD BE
SCATTERED COVERAGE OF SHOWERS AND TSTMS MAINLY IN SOUTHERN SC THIS
AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THE COLD FRONT WILL MOVE THROUGH SHORTLY AFTER MIDNIGHT TONIGHT
WITH SLIGHTLY DRIER AIR BEGINNING TO FILTER IN. MOSTLY CLEAR SKIES
EXPECTED WITH TEMPERATURES IN THE LOWER 60S.
FRIDAY AND FRIDAY NIGHT...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE
MID-ATLANTIC REGION ON FRIDAY. IN WAKE OF THE DEPARTING COLD
FRONT...A DEEP LAYERED NORTHWEST FLOW WILL PREVAIL THROUGH MUCH OF
THE DAY. THE DOWNSLOPE FLOW WILL RESULT IN DRYING ACROSS THE AREA
AND WILL ALSO NEGATE MOST OF THE INITIAL SURGE OF COLD AIR ADVECTION
AS HIGHS SHOULD STILL BE IN THE MID TO UPPER 80S. UNDER MOSTLY SUNNY
SKIES...BREEZY CONDITIONS ARE ALSO EXPECTED. THEN...AS THE UPPER
TROUGH PASSES OFF THE MID-ATLANTIC COAST FRIDAY EVENING...IT WILL
PUSH A SECONDARY COLD FRONT ACROSS THE AREA ALLOWING HIGH PRESSURE
TO BUILD FROM THE GREAT LAKES REGION. THE AIRMASS WILL BEGIN TO
MODIFY SIGNIFICANTLY FOLLOWING THE SECONDARY COLD FRONT WITH
TEMPERATURES PLUMMETING INTO THE UPPER 40S AND LOWER 50S FRIDAY
NIGHT ON A NORTHERLY FLOW.
SATURDAY AND SATURDAY NIGHT...A VERY DRY AIRMASS WILL SETTLE OVER
THE REGION SATURDAY AS HIGH PRESSURE CONTINUES TO BUILD IN FROM THE
GREAT LAKES REGION. PRECIPITABLE WATER VALUES OF .25 TO .40 INCHES
WILL BE ABOUT AS LOW AS THEY CAN GET FOR THIS TIME OF YEAR...OR MORE
THAN 2 STANDARD DEVIATIONS BELOW NORMAL. FORECAST THICKNESS VALUES
ONLY SUPPORT HIGHS IN THE MID TO UPPER 70S...BUT GIVEN FULL SUNSHINE
AND THE HIGHER SUN ANGLE THIS TIME OF YEAR...WILL INDICATE HIGHS IN
THE UPPER 70S TO LOWER 80S ACROSS THE AREA. ANOTHER UNSEASONABLY
COOL NIGHT IS EXPECTED SATURDAY NIGHT...WITH LOWS IN THE LOWER TO
MID 50S.
SUNDAY...A WEAK PRESSURE PATTERN WILL PREVAIL OVER THE REGION. AN
INCREASE IN MID AND HIGH LEVEL MOISTURE WILL SUPPORT SOME CLOUD
COVER BUT THE AIRMASS IS TOO DRY STILL FOR ANY SHOWERS TO DEVELOP.
HIGHS SHOULD BE IN THE LOWER TO MID 80S ACROSS MUCH OF THE AREA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE REGION WILL BE SANDWICHED BETWEEN TWO AREAS OF HIGH PRESSURE
EARLY IN THE WEEK...THE STRONGER OF THE TWO PASSING ACROSS THE
MID-ATLANTIC REGION AND THE OTHER OVER THE NORTHEAST GULF OF MEXICO.
DEEPENING MOISTURE WILL RESULT IN AT LEAST AN INCREASE IN CLOUD
COVER...BUT IT APPEARS THE RAIN-FREE CONDITIONS SHOULD PERSIST
THROUGH MEMORIAL DAY. ATLANTIC HIGH PRESSURE WILL THEN BECOME
ESTABLISHED THROUGH THE MIDDLE OF NEXT WEEK...SUPPORTING MAINLY
DIURNAL ISOLATED CONVECTION EACH AFTERNOON ALONG AND AHEAD OF THE
SEA BREEZE TUESDAY THROUGH THURSDAY. TEMPERATURES WILL MODERATE TO
NEAR NORMAL BY EARLY NEXT WEEK AND CONTINUE NEAR SEASONAL NORMS
THROUGH THE END OF THE FORECAST PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
ASSUMING NONE OF THE UPSTREAM SHOWER AND TSTM ACTIVITY MAKES IT
INTO THE TERMINALS PRIOR TO DAYBREAK...FAIRLY QUIET CONDITIONS
ANTICIPATED. WE EXPECT AN INCREASE IN MID AND HIGH CLOUDS LATE
TONIGHT IN ASSOCIATION WITH A SHORTWAVE MOVING THROUGH. THIS WILL
LIMIT FOG POTENTIAL. LATER TODAY...A PRE-FRONTAL TROUGH WILL PUSH
THROUGH MAINLY SOUTHERN SC. CONVERGENCE ALONG THIS BOUNDARY MAY
SPUR SOME SHOWERS OR STORMS NEAR KCHS EARLY THIS AFTERNOON.
OTHERWISE DRYING CONDITIONS BY EARLY THIS EVENING WITH SKIES
GRADUALLY CLEARING.
EXTENDED AVIATION...VFR CONDITIONS WILL PREVAIL. GUSTY WINDS ARE
POSSIBLE FRIDAY AFTERNOON.
&&
.MARINE...
WINDS/SEAS WILL BE FAIRLY LOW THROUGH TODAY...THEN WINDS INCREASE
OUT OF THE SW AND W TONIGHT AS A COLD FRONT PUSHES THROUGH THE
WATERS. WIND SPEEDS WILL TOP OUT AROUND 15 KT BUT THE OFFSHORE
FETCH WILL LIMIT THE BUILDING OF SEAS TO NO HIGHER THAN 4 FT.
FRIDAY THROUGH TUESDAY...A NORTHWEST FLOW WILL DEVELOP ON FRIDAY IN
WAKE OF A DEPARTING COLD FRONT. A SECONDARY COLD FRONT WILL THEN
MOVE THROUGH BY FRIDAY EVENING...WITH A STRONGER NORTHERLY SURGE
DEVELOPING IN ITS WAKE FRIDAY NIGHT INTO EARLY SATURDAY...POSSIBLY
RESULTING IN SMALL CRAFT ADVISORY CONDITIONS OVER A PORTION OF THE
WATERS.
CONDITIONS WILL THEN IMPROVE LATER IN THE WEEKEND WITH WINDS/SEAS
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH
EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JRL
SHORT TERM...JAQ/JRL
LONG TERM...JAQ
AVIATION...JAQ/JRL
MARINE...JAQ/JRL
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 230807
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
407 AM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE AND INSTABILITY AHEAD OF A MID-LEVEL SHORTWAVE TROUGH
WAS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS EARLY THIS
MORNING. SATELLITE TRENDS AND THE MODELS INDICATE DEEPER MOISTURE
ASSOCIATED WITH THIS FEATURE WILL SHIFT EAST OF THE FORECAST AREA
LATER THIS MORNING. A PRE-FRONTAL TROUGH WILL BE IN THE FORECAST
AREA TODAY. CONVERGENCE ASSOCIATED WITH THIS FEATURE PLUS DIURNAL
HEATING SHOULD SUPPORT THUNDERSTORMS BUT EXPECT LIMITED COVERAGE
BECAUSE OF DIMINISHED MOISTURE BEHIND THE MID-LEVEL SHORTWAVE
TROUGH. MAINTAINED CHANCE POPS WITH THE GREATER VALUES IN THE
NORTHEAST PART CLOSER TO DEEPER MOISTURE AND MORE CONVERGENCE
ASSOCIATED WITH THE SURFACE TROUGH. MODERATE INSTABILITY MAY
SUPPORT DAMAGING WIND WITH A FEW OF THE THUNDERSTORMS. WET-BULB
ZERO HEIGHTS ALSO SUPPORT HAIL. THE TEMPERATURE GUIDANCE WAS
CLOSE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY SUPPORT
THUNDERSTORMS EARLY. COVERAGE SHOULD STILL BE LIMITED WITH DEEPER
MOISTURE EAST OF THE AREA. DRYING BEHIND THE FRONT SHOULD DOMINATE
LATE TONIGHT THROUGH FRIDAY NIGHT. MIXING ASSOCIATED WITH THE
FRONT SUPPORTED THE WARMER TEMPERATURE GUIDANCE TONIGHT. WE WILL
GET OFF TO A RELATIVELY WARM START SO THE WARMER GUIDANCE APPEARED
BETTER FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FRIDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. EXPECT SOME INCREASE IN MOISTURE BEGINNING MONDAY. THE
GFS AND ECMWF DISPLAY A WARM FRONT DEVELOPING NEAR THE AREA. THE
GFS IS FARTHER NORTHWARD WITH THE PLACEMENT OF THE FRONT. THE GFS
ALSO SHOWS LESS MOISTURE IN THE FORECAST AREA. BOTH MODELS SHOW
AN INCREASE IN H5 RIDGING WHICH SHOULD LIMIT THUNDERSTORMS.
BELIEVE THE BEST FORECAST FOR NOW IS AN AVERAGE OF THE GFS AND
ECMWF MOS. FORECASTED SLIGHT CHANCE POPS TUESDAY AND WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
CONVECTION CONTINUES TO SLOWLY WEAKEN AS IT MOVES TO THE ENE. MOST
ACTIVITY CURRENTLY CONFINED TO THE UPSTATE SC AND EASTERN GA. HIGH
RES MODELS CONTINUE TO SUGGEST THE ACTIVITY WILL GRADUALLY WEAKEN AS
IT MOVES INTO THE AREA. WILL MENTION A TEMPO GROUP FOR SHOWERS FOR
AGS/DNL UNTIL AROUND 09Z-10Z...OTHERWISE NOT ENOUGH CONFIDENCE TO
MENTION PRECIP AT THE OTHER TAF SITES.
GUIDANCE ALSO CONTINUING TO INDICATE CIG RESTRICTIONS EARLY THIS
MORNING...IN A CONTINUED MOIST SOUTHERLY LOW LEVEL FLOW. FOR
NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL MONITOR LATEST
GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED. UPPER IMPULSE AND
SURFACE TROUGH WILL MOVE THROUGH LATER TODAY...POSSIBLY LEADING TO
SCT SHRA/TSRA. DUE TO THE SCATTERED NATURE OF THE CONVECTION...WILL
NOT MENTION PRECIPITATION AT ANY OF THE TAF SITES FOR THE AFTERNOON
HOURS. BY LATE THIS EVENING...SKIES SHOULD BEGIN TO CLEAR AS DRIER
AIR MOVES INTO THE AREA FROM THE WEST.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NIGHT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KFFC 230800
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
400 AM EDT THU MAY 23 2013
.SHORT TERM /TODAY THROUGH FRIDAY/...
UPPER LEVEL TROUGH MOVING THROUGH EASTERN SECTIONS OF GA INTO THE
CAROLINAS THIS MORNING. SHOWERS AND THUNDERSTORMS HAVE BEEN
DIMINISHING OVER EASTERN GA AND SHOULD CONTINUE TO DO SO. SOME
LINGERING DYNAMICS MAY SUPPORT SOME CONVECTION MAINLY ALONG THE
EASTERN SIDE OF THE CWA THIS MORNING AND HAVE CONTINUED WITH LOW
POPS FOR THAT AREA. DRIER AIR WILL SPREAD INTO THE CWA TODAY BEHIND
THE SHORT WAVE. HOWEVER...NORTH GA WILL BE ON THE SOUTHERN FRINGES
OF AN UPPER TROUGH DEEPENING INTO THE OHIO AND TENNESSEE VALLEYS
THIS AFTERNOON AND EVENING. SO...HAVE LEFT LOW POPS ACROSS THE
EXTREME NORTHERN COUNTIES THIS AFTERNOON UNTIL AROUND 06Z. OTHERWISE
STRONG NORTHWESTERLY FLOW BRINGING LOWER DEW POINTS AND MORE STABLE
AIR FOR THE REMAINDER OF THE SHORT TERM. NORTHWEST WINDS BECOMING
GUSTY TODAY BUT SHOULD STAY BELOW ADVISORY CRITERIA. SOMEWHAT COOLER
TEMPERATURES IN STORE TONIGHT AND FRIDAY. MAV/MET NUMBERS WERE CLOSE
AND ONLY MINOR TWEAKS WERE MADE.
41
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DRY WEATHER IS EXPECTED TO CONTINUE ACROSS THE AREA THROUGH SUNDAY
AND FOR THE MOST PART BASED ON THE GFS...THROUGH THURSDAY.
HOWEVER THE EUROPEAN MODEL IS INDICATING A WETTER NW FLOW ALOFT
ACROSS N AND PARTS OF CENTRAL GA STARTING SUNDAY NIGHT WITH A
WEAKER UPPER RIDGE AND GREATER POTENTIAL FOR SHORT WAVES TO AFFECT
THE AREA. CURRENT FORECAST HAS LOW POPS ACROSS N GA ON MONDAY AND
TUESDAY AND WILL JUST CONTINUE THAT FORECAST FOR NOW AS A
COMPROMISE. NO INSTABILITY TO SPEAK OFF UNTIL TUESDAY AFTERNOON
WHERE THERE MIGHT BE ENOUGH FOR THUNDERSTORMS OVER FAR N GA. UPPER
RIDGE OVER THE AREA FOR WEDNESDAY INTO THURSDAY. KEEPING POPS NIL
FOR WEDNESDAY EXCEPT FOR LOW POPS OVER THE NE MOUNTAINS WHERE
SOUTHERLY FLOW AND SOME INSTABILITY COULD CAUSE AFTERNOON SHOWERS
AND STORMS.
TEMPERATURES GENERALLY RUNNING WITHIN 6 DEGREES OF NORMAL THROUGH
THE PERIOD EXCEPT SATURDAY MORNING LOWS ARE RUNNING ABOUT 10-15
DEGREES BELOW NORMAL AND SUNDAY MORNING LOWS RUNNING ABOUT 6-12
DEGREES BELOW NORMAL.
BDL
&&
.AVIATION...
06Z UPDATE...
SHOWERS/THUNDERSTORMS HAVE MOVED PAST ALL TAF SITES EXCEPT ATHENS
AND MACON. SOME SCT TO BKN040 TO LINGER FOR THE REMAINDER OF THE
NIGHT. EXPECT VFR AFTER SUNRISE WITH SCT040-050. MVFR AND POSSIBLY
IFR FOG EXPECTED UNTIL 14Z MAINLY FOR PDK...AHN...MCN. ONLY ISOLATED
CONVECTION MAINLY NORTH AND EAST OF TAF SITES TODAY. WINDS WILL
BECOME NORTHWEST 10KT AFTER SUNRISE WITH GUSTS TO 20-25KT POSSIBLE.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON IFR FOG THIS MORNING.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 86 58 80 46 / 20 5 0 0
ATLANTA 84 59 76 50 / 10 0 0 0
BLAIRSVILLE 79 53 73 40 / 20 20 0 0
CARTERSVILLE 85 56 77 44 / 10 5 0 0
COLUMBUS 87 63 84 55 / 10 0 0 0
GAINESVILLE 83 58 79 48 / 20 10 0 0
MACON 88 59 83 48 / 10 0 0 0
ROME 85 56 78 46 / 10 10 0 0
PEACHTREE CITY 84 56 78 46 / 10 0 0 0
VIDALIA 88 65 87 56 / 20 0 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41
LONG TERM....BDL
AVIATION...41
000
FXUS62 KCHS 230612
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
212 AM EDT THU MAY 23 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THERE ARE SOME CHANGES THAT WILL TAKE PLACE IN THE LARGER
SCALE...AS THE FIRST SHORT WAVE OFF THE EASTERN FLORIDA COAST WILL
GET LIFTED NE AS THE NEXT LONG WAVE TROUGH IN THE MISSISSIPPI VALLEY
SHIFTS EAST. IN ADVANCE OF THE LONG WAVE IS A DECENT SHORT WAVE
MOVING THROUGH NE AND CENTRAL GA THAT WILL APPROACH OUR BORDER LATE.
AS THIS TRANSPIRES...IT FORCES THE LAST GRIPS OF THE ATLANTIC RIDGE
TO PULL OFFSHORE AFTER MIDNIGHT...AS A PRE-FRONTAL TROUGH IN WESTERN
GEORGIA APPROACHES LATE. THE FORECAST AREA WILL THEN LIE SANDWICHED
BETWEEN THE FIRST SHORT WAVE IN THE NEARBY ATLANTIC AND THE SECOND
IMPULSE AND ITS REFLECTION AT THAT SURFACE. WHILE THERE IS SOME
INCREASE IN LOW LEVEL CONVERGENCE TO THE EAST...THE SYNOPTIC FLOW
MAY VEER TOO FAR TO THE SW TO ALLOW FOR ANYTHING MORE THAN LOW END
POPS OVER CHARLESTON COUNTY CLOSE TO DAYBREAK. UPSTREAM IT APPEARS
THAT THE BEST FORCING WILL STAY TO THE WEST...BUT A FEW SHOWERS OR
T-STORMS COULD SNEAK INTO THE SW CORNER LATE. FOR NOW WE HAVE SHOWN
POPS AT 14 PERCENT OR LESS FOR ALL BUT NORTHERN CHARLESTON COUNTY
AND CANDLER AND JENKINS WHERE 20 POPS WILL BE SUFFICIENT.
WHILE CONDITIONS ARE NOT AS FAVORABLE FOR FOG DEVELOPMENT AS LAST
NIGHT /IE. TOO MUCH WIND IN THE BOUNDARY LAYER UNTIL LATE AND
MUCH LESS RAINFALL/...WE HAVE MAINTAINED MENTION OF PATCHY FOG TO
OUR NW TIER WHERE THEY HAVE A BETTER CHANCE OF ACHIEVING THEIR
CROSS-OVER TEMPS AND FOG STABILITY INDICES ARE IN THE LOWER 20S.
THE MIXING IN THE BOUNDARY LAYER AND AN INCREASE IN CLOUD COVER
WILL LIMIT TEMPS TO ONLY THE MID AND UPPER 60S INLAND FROM THE
SLIGHTLY WARMER BEACHES.
FOR THOSE THAT ARE INTERESTED...TEMPS AGAIN FAILED TO HIT 90
DEGREES AT BOTH KCHS AND KSAV WEDNESDAY. THIS CONTINUES THE
STRETCH OF SUB-90 DEGREE DAYS AT 257 STRAIGHT AT KCHS AND 256
STRAIGHT AT KSAV DATING BACK TO EARLY SEPTEMBER 2012.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
A SURFACE PRESSURE TROF WILL MOVE INTO THE CWA ON THURSDAY...WITH
MOIST SOUTHERLY WINDS AHEAD OF IT AND SOMEWHAT DRIER WESTERLY WINDS
BEHIND IT. THE TROF SHOULD BE ROUGHLY ALONG INTERSTATE 95 BY EARLY
AFTERNOON...AND AREAS ALONG AND EAST OF THE BOUNDARY WILL HAVE A
CHANCE OF SHOWERS AND THUNDERSTORMS AS DAYTIME HEATING CREATES SOME
SURFACE INSTABILITY AND CONVERGENCE. FURTHER WEST...ESPECIALLY OVER
OUR INTERIOR GEORGIA COUNTIES...THE ATMOSPHERE WILL BE DRIER AND
MORE STABLE...SO THERE WILL ONLY BE A SLIGHT CHANCE OF SHOWERS.
SKIES SHOULD AVERAGE OUT PARTLY CLOUDY...ALTHOUGH THERE WILL BE A
PERIOD OF MOSTLY CLOUDY SKIES TO THE EAST OF THE BOUNDARY DURING A
PORTION OF THE AFTERNOON.
THURSDAY NIGHT...THE INITIAL COOL FRONT PUSHES THROUGH THE
AREA...MOVING THE CHANCES FOR RAIN MOSTLY OFFSHORE...ALTHOUGH I
CANNOT RULE OUT A SLIGHT CHANCE OVER THE TRI COUNTY AREA AS THERE
MAY BE ENOUGH REMNANT MOISTURE WITH THE FRONT TO PROMOTE SOME
SHOWERS.
FRIDAY...THE WINDS WILL BE NORTHWEST BEHIND THE FRONT IN THE
MORNING...PROMOTING SOME DOWNSLOPE LOW LEVEL FLOW AND HEATING.
HOWEVER...DRIER AIR MOVING IN SHOULD PREVENT ANY RAIN...OR MUCH IN
THE WAY OF CLOUDS FOR THAT MATTER. A SECONDARY COLD FRONT WILL MOVE
THROUGH LATER IN THE DAY...CAUSING THE WINDS TO VEER TO NORTH AND
INCREASE AS COLD ADVECTION PICKS UP. FRIDAY NIGHT WILL BE MUCH
COOLER THAN THE PREVIOUS FEW.
SATURDAY...TEMPS WILL BEGIN WELL BELOW NORMAL AS MODIFIED AIR POURS
IN TO THE AREA...BUT THIS TIME OF YEAR THAT MEANS TEMPS MAINLY IN
THE 50S. PLENTY OF SUNSHINE WILL ALLOW AFTERNOON MAX TEMPS TO REACH
TO 80 OR ABOVE...BUT DEWPOINTS WILL DROP INTO THE 40S AWAY FROM THE
COAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
ASSUMING NONE OF THE UPSTREAM SHOWER AND TSTM ACTIVITY MAKES IT
INTO THE TERMINALS PRIOR TO DAYBREAK...FAIRLY QUIET CONDITIONS
ANTICIPATED. WE EXPECT AN INCREASE IN MID AND HIGH CLOUDS LATE
TONIGHT IN ASSOCIATION WITH A SHORTWAVE MOVING THROUGH. THIS WILL
LIMIT FOG POTENTIAL. LATER TODAY...A PRE-FRONTAL TROUGH WILL PUSH
THROUGH MAINLY SOUTHERN SC. CONVERGENCE ALONG THIS BOUNDARY MAY
SPUR SOME SHOWERS OR STORMS NEAR KCHS EARLY THIS AFTERNOON.
OTHERWISE DRYING CONDITIONS BY EARLY THIS EVENING WITH SKIES
GRADUALLY CLEARING.
EXTENDED AVIATION...VFR. WINDS COULD GET A BIT GUSTY FRIDAY AFTERNOON
BEHIND THE SECONDARY FRONT.
&&
.MARINE...
TONIGHT...THE SUB TROPICAL RIDGE IN THE ATLANTIC CENTERED OUT NEAR
32N AND 60W WILL START TO RELAX ITS GRIP ACROSS THE COASTAL WATERS
LATE...AS IT STARTS TO GIVE WAY TO AN UPSTREAM PRE-FRONTAL TROUGH.
THE PRESSURE GRADIENT WILL TEMPORARILY TIGHTEN A BIT BETWEEN THESE
TWO FEATURES...ALLOWING FOR SE AND SOUTH WINDS UP TO 15 KT THROUGH
ABOUT 06-08Z...BEFORE VEERING ABOUT 10-30 DEGREES AND DROPPING
OFF TO 10 OR LESS LATE. SEAS WON/T CHANGE MUCH...AVERAGING 2-4 FT
AND HIGHEST ACROSS THE OUTER GA WATERS. WE/LL NEED TO MONITOR FOR
SOME GUSTY SHOWERS/T-STORMS OVERNIGHT AS LOW LEVEL CONVERGENCE
INCREASES.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JRL
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...JRL
MARINE...
TIDES/COASTAL FLOODING...
000
FXUS62 KFFC 230547 AAA
AFDFFC
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
140 AM EDT THU MAY 23 2013
.UPDATE...
QUICK UPDATE TO GRIDS. APPEARS COVERAGE OF TSRA OVER ERN AL AND
WRN GA LOWER THAN MODEL FCSTS. WILL BACK OFF ON POPS. MLCAPE
PRETTY STOUT WITH VALUES 1500-2000 J/KG AND 0-6KM BULK SHEAR
AROUND 20-30KTS. APPARENTLY FORCING AND LOCALIZED LIFT IS LACKING.
WILL CONTINUE TO MONITOR.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 350 PM EDT WED MAY 22 2013/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AFTERNOON CONVECTION EXPECTED TO INCREASE IN COVERAGE AND PERSIST
INTO THE EVENING AND OVERNIGHT HOURS AS UPPER LEVEL TROUGH MOVES
THROUGH THE MISSISSIPPI VALLEY. CONVECTION EXPECTED TO BECOME MORE
ORGANIZED AS ASSOCIATED SHORT WAVE FOCUSES DEVELOPMENT. MODELS A
LITTLE INCONSISTENT WITH THE DEVELOPMENT AND/OR PROGRESSION OF THE
ORGANIZED PRECIPITATION...BUT WITH INCREASING
INSTABILITIES...DIURNAL HEATING...AND INCREASING SHEAR ACROSS THE
AREA...FEEL THERE IS ENOUGH TO SUPPORT GOOD CHANCE TO LIKELY
POPS...ESPECIALLY ACROSS NORTH GEORGIA. HAVE CONTINUED MENTION OF
POSSIBLE SEVERE STORMS...ACCOMPANIED WITH GUSTY WINDS AND SMALL
HAIL...IN THE GRIDS THROUGH 02Z TONIGHT ACROSS NORTH
GEORGIA...GENERALLY NORTH OF THE ATL METRO AREA. HAVE ALSO
QUICKLY TAPERED OFF EVENING AND OVERNIGHT POPS INTO THURSDAY
MORNING...WITH GENERALLY SLIGHT CHANCE POPS ACROSS THE AREA THROUGH
THE DAY THURSDAY AS SHORT WAVE PUSHES INTO THE CAROLINAS.
AS PREVIOUSLY MENTIONED...THE SEVERE THREAT IS PRIMARILY CONFINED TO
NORTH GEORGIA...THOUGH STRONG STORMS CAN BE EXPECTED ACROSS MUCH OF
THE CWA. THE PRIMARY CONCERNS IN SEVERE ACTIVITY WILL BE GUSTY WINDS
TO 60 MPH OR HIGHER...1 INCH HAIL OR HIGHER...FREQUENT LIGHTNING AND
PERIODS OF HEAVY RAINFALL. GUSTY WINDS AND SMALL HAIL ARE ALSO
POSSIBLE IN THE STRONGER STORMS.
PRESSURE GRADIENT TIGHTENS THURSDAY AFTERNOON AND INTO FRIDAY...WITH
WINDS 10 TO 15 MPH WITH GUSTS NEAR 20 MPH...ESPECIALLY ACROSS
NORTHERN AND EASTERN GEORGIA.
FOR THE TEMPERATURES..HAVE GENERALLY GONE WITH A GUIDANCE BLEND.
TEMPERATURES THURSDAY MORNING ARE EXPECTED TO BE IN THE 60S...AND
DEPENDING ON THE TIMING OF THE DIMINISHING CONVECTION AND CLOUDS OUT
OF THE AREA...THIS COULD IMPACT MORNING LOWS BY A FEW DEGREES.
TEMPERATURES WILL BE BACK IN THE LOW TO MID 80S THURSDAY AFTERNOON
BEFORE COOLING BY FRIDAY.
31
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED PORTION OF THE FORECAST. A MUCH
DRIER AIRMASS MOVES OVER THE AREA FRIDAY WITH DRY NW FLOW ALOFT
AND SURFACE HIGH PRESSURE BUILDING OVER THE OH/TN VALLEYS DURING
THE DAY. GRADIENT WINDS WILL INCREASE GETTING CLOSE TO WIND
ADVISORY CRITERIA(20 MPH SUSTAINED) FOR SOME AREAS. DRY CONDITIONS
SHOULD CONTINUE THROUGH THE WEEKEND EVEN WITH SLIGHT DIFFERENCES
BETWEEN THE GFS AND ECMWF. THE NW FLOW ALOFT N OF THE AREA IS
EXPECTED TO BECOME MORE ACTIVE WITH INCREASED PRECIP CHANCES NORTH
OF THE STATE...BUT IT SHOULD STAY DRY ACROSS GA. LOOKS LIKE THE
BETTER MOISTURE FINALLY MOVES IN ACROSS THE AREA BY THE BEGINNING
OF NEXT WEEK SO WILL SLOWLY INCREASE CHANCES OF POPS MON THROUGH DAY
7. TEMPERATURES GENERALLY RUNNING WITHIN 5 DEGREES OF NORMAL
THROUGH THE PERIOD EXCEPT SATURDAY ND SUNDAY MORNING LOWS ARE
RUNNING 10-15 DEGREES BELOW NORMAL.
01
&&
.AVIATION...
06Z UPDATE...
SHOWERS/THUNDERSTORMS HAVE MOVED PAST ALL TAF SITES EXCEPT ATHENS
AND MACON. SOME SCT TO BKN040 TO LINGER FOR THE REMAINDER OF THE
NIGHT. EXPECT VFR AFTER SUNRISE WITH SCT040-050. MVFR AND POSSIBLY
IFR FOG EXPECTED UNTIL 14Z MAINLY FOR PDK...AHN...MCN. ONLY ISOLATED
CONVECTION MAINLY NORTH AND EAST OF TAF SITES TODAY. WINDS WILL
BECOME NORTHWEST 10KT AFTER SUNRISE WITH GUSTS TO 20-25KT POSSIBLE.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON IFR FOG THIS MORNING.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 85 59 79 / 60 20 5 0
ATLANTA 66 83 59 76 / 70 10 5 0
BLAIRSVILLE 61 78 54 71 / 70 20 10 0
CARTERSVILLE 64 83 57 76 / 70 10 5 0
COLUMBUS 68 89 63 82 / 70 10 5 0
GAINESVILLE 64 82 57 75 / 70 10 5 0
MACON 66 89 60 83 / 60 20 5 0
ROME 64 84 57 77 / 50 10 5 0
PEACHTREE CITY 64 85 58 77 / 70 10 5 0
VIDALIA 68 89 65 88 / 40 20 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...SNELSON
000
FXUS62 KCAE 230531
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
131 AM EDT THU MAY 23 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
MOISTURE AND INSTABILITY AHEAD OF A MID-LEVEL SHORTWAVE TROUGH
WAS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS EARLY THIS
MORNING. SATELLITE TRENDS AND THE MODELS INDICATE DEEPER MOISTURE
ASSOCIATED WITH THIS FEATURE WILL SHIFT EAST OF THE FORECAST AREA
LATER THIS MORNING. A PRE-FRONTAL TROUGH WILL BE IN THE FORECAST
AREA TODAY. CONVERGENCE ASSOCIATED WITH THIS FEATURE PLUS DIURNAL
HEATING SHOULD SUPPORT THUNDERSTORMS BUT EXPECT LIMITED COVERAGE
BECAUSE OF DIMINISHED MOISTURE BEHIND THE MID-LEVEL SHORTWAVE
TROUGH. MAINTAINED CHANCE POPS WITH THE GREATER VALUES IN THE
NORTHEAST PART CLOSER TO DEEPER MOISTURE AND MORE CONVERGENCE
ASSOCIATED WITH THE SURFACE TROUGH. MODERATE INSTABILITY MAY
SUPPORT DAMAGING WIND WITH A FEW OF THE THUNDERSTORMS. WET-BULB
ZERO HEIGHTS ALSO SUPPORT HAIL. THE TEMPERATURE GUIDANCE WAS
CLOSE.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY SUPPORT
THUNDERSTORMS EARLY. COVERAGE SHOULD STILL BE LIMITED WITH DEEPER
MOISTURE EAST OF THE AREA. DRYING BEHIND THE FRONT SHOULD DOMINATE
LATE TONIGHT THROUGH FRIDAY NIGHT. MIXING ASSOCIATED WITH THE
FRONT SUPPORTED THE WARMER TEMPERATURE GUIDANCE TONIGHT. WE WILL
GET OFF TO A RELATIVELY WARM START SO THE WARMER GUIDANCE APPEARED
BETTER FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FRIDAY NIGHT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA. THE
GFS ENSEMBLE MEAN PLUS GFS AND ECMWF MOS SUPPORTED VERY LOW POPS. EXPECT
BELOW NORMAL TEMPERATURES DURING THE WEEKEND...AND NEAR NORMAL
READINGS DURING THE REST OF THE MEDIUM-RANGE PERIOD.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
CONVECTION CONTINUES TO SLOWLY WEAKEN AS IT MOVES TO THE ENE. MOST
ACTIVITY CURRENTLY CONFINED TO THE UPSTATE SC...STRETCHING SW ACROSS
NE AND CENT GA. LATEST HIGH RES MODELS SUGGEST THE ACTIVITY WILL
GRADUALLY WEAKEN AND DISSIPATE AS IT APPROACHES THE CSRA. WILL
MENTION A TEMPO GROUP FOR SHOWERS FOR AGS/DNL UNTIL AROUND
09Z...OTHERWISE NOT ENOUGH CONFIDENCE TO MENTION PRECIP AT THE OTHER
TAF SITES.
GUIDANCE ALSO CONTINUING TO INDICATE CIG RESTRICTIONS LATE
TONIGHT/EARLY THURSDAY MORNING...IN A CONTINUED MOIST SOUTHERLY LOW
LEVEL FLOW. FOR NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL
MONITOR LATEST GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED.
UPPER IMPULSE AND SURFACE TROUGH WILL MOVE THROUGH
THURSDAY...POSSIBLY LEADING TO SCT SHRA/TSRA. CURRENT THINKING IS
THAT MOST OF THE ACTIVITY THURSDAY WILL BE EAST OF THE TERMINALS.
WILL NOT MENTION IN THE TAFS AT THIS TIME. BY LATE THIS
EVENING...SKIES SHOULD BEGIN TO CLEAR AS DRIER AIR MOVES INTO THE
AREA FROM THE WEST.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NIGHT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCAE 230351
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1151 PM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH RESOLUTION WRF INDICATES THUNDERSTORMS MOVING INTO THE AREA
FROM THE WEST WILL DIMINISH. RADAR TRENDS SUPPORT THIS. CLOUDINESS
SHOULD HELP HOLD UP TEMPERATURES. THE TEMPERATURE FORECAST APPEARS
ON TRACK.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSING THE EASTERN CONUS DURING THE
SHORT TERM. THE AIR MASS WILL BE UNSTABLE WITH A PRE-FRONTAL TROUGH
OVER THE MIDLANDS. LOW LEVEL MOISTURE LINGERS WITH PRECIPITABLE
WATER RANGING FROM 1.00 T0 1.75 INCHES. THE THREAT OF CONVECTION
WILL CONTINUE WITH THE HIGHEST CHANCE ACROSS THE EAST MIDLANDS.
WILL RANGE POPS FROM NEAR 30 PERCENT CSRA TO 60 PERCENT NORTHEAST
ON THURSDAY. ALTHOUGH THE GFS IS SLIGHTLY FASTER...MODELS INDICATE
THE COLD FRONT CROSSING THE AREA THURSDAY NIGHT WITH THE CHANCE OF
CONVECTION ENDING. CUT POPS AFTER 18Z FROM PREVIOUS FORECAST BASED
ON LATEST MODEL TRENDS.
THE TEMPERATURE GUIDANCE WAS CLOSE WITH HIGHS IN THE MID/UPPER 80S
AND LOWS IN THE LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
THROUGH WEDNESDAY. GFS ENSEMBLE INCREASE POPS SLIGHTLY THROUGH THE
MIDDLE OF NEXT WEEK. WILL KEEP THE FORECAST DRY GIVEN INCREASING
H500 HEIGHTS AS THE UPPER RIDGE BUILDS.
EXPECT BELOW NORMAL TEMPERATURES DURING THE WEEKEND AND NEAR NORMAL
DURING THE REST OF THE MEDIUM RANGE PERIOD.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
RADAR CURRENTLY INDICATES CONVECTIVE ACTIVITY AT A MINIMUM ACROSS
OUR FA. MOST ACTIVITY CURRENTLY CONFINED TO THE UPSTATE
SC...STRETCHING SW ACROSS NE AND CENT GA. THIS ACTIVITY MOVING
SLOWLY TO THE ENE. LATEST HIGH RES MODELS SUGGEST THE ACTIVITY WILL
GRADUALLY WEAKEN AND DISSIPATE AS IT APPROACHES THE CSRA. FOR
NOW...NOT ENOUGH CONFIDENCE TO MENTION PRECIP IN AGS/DNL TAFS...BUT
WILL MONITOR.
GUIDANCE ALSO CONTINUING TO INDICATE CIG RESTRICTIONS LATE
TONIGHT/EARLY THURSDAY MORNING...IN A CONTINUED MOIST SOUTHERLY LOW
LEVEL FLOW. FOR NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL
MONITOR LATEST GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED.
UPPER IMPULSE AND SURFACE TROUGH WILL MOVE THROUGH
THURSDAY...POSSIBLY LEADING TO SCT SHRA/TSRA. CURRENT THINKING IS
THAT MOST OF THE ACTIVITY THURSDAY WILL BE EAST OF THE TERMINALS.
WILL NOT MENTION IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 230251
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1050 PM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
THERE ARE SOME CHANGES THAT WILL TAKE PLACE IN THE LARGER
SCALE...AS THE FIRST SHORT WAVE OFF THE EASTERN FLORIDA COAST WILL
GET LIFTED NE AS THE NEXT LONG WAVE TROUGH IN THE MISSISSIPPI VALLEY
SHIFTS EAST. IN ADVANCE OF THE LONG WAVE IS A DECENT SHORT WAVE
MOVING THROUGH NE AND CENTRAL GA THAT WILL APPROACH OUR BORDER LATE.
AS THIS TRANSPIRES...IT FORCES THE LAST GRIPS OF THE ATLANTIC RIDGE
TO PULL OFFSHORE AFTER MIDNIGHT...AS A PRE-FRONTAL TROUGH IN WESTERN
GEORGIA APPROACHES LATE. THE FORECAST AREA WILL THEN LIE SANDWICHED
BETWEEN THE FIRST SHORT WAVE IN THE NEARBY ATLANTIC AND THE SECOND
IMPULSE AND ITS REFLECTION AT THAT SURFACE. WHILE THERE IS SOME
INCREASE IN LOW LEVEL CONVERGENCE TO THE EAST...THE SYNOPTIC FLOW
MAY VEER TOO FAR TO THE SW TO ALLOW FOR ANYTHING MORE THAN LOW END
POPS OVER CHARLESTON COUNTY CLOSE TO DAYBREAK. UPSTREAM IT APPEARS
THAT THE BEST FORCING WILL STAY TO THE WEST...BUT A FEW SHOWERS OR
T-STORMS COULD SNEAK INTO THE SW CORNER LATE. FOR NOW WE HAVE SHOWN
POPS AT 14 PERCENT OR LESS FOR ALL BUT NORTHERN CHARLESTON COUNTY
AND CANDLER AND JENKINS WHERE 20 POPS WILL BE SUFFICIENT.
WHILE CONDITIONS ARE NOT AS FAVORABLE FOR FOG DEVELOPMENT AS LAST
NIGHT /IE. TOO MUCH WIND IN THE BOUNDARY LAYER UNTIL LATE AND
MUCH LESS RAINFALL/...WE HAVE MAINTAINED MENTION OF PATCHY FOG TO
OUR NW TIER WHERE THEY HAVE A BETTER CHANCE OF ACHIEVING THEIR
CROSS-OVER TEMPS AND FOG STABILITY INDICES ARE IN THE LOWER 20S.
THE MIXING IN THE BOUNDARY LAYER AND AN INCREASE IN CLOUD COVER
WILL LIMIT TEMPS TO ONLY THE MID AND UPPER 60S INLAND FROM THE
SLIGHTLY WARMER BEACHES.
FOR THOSE THAT ARE INTERESTED...TEMPS AGAIN FAILED TO HIT 90
DEGREES AT BOTH KCHS AND KSAV WEDNESDAY. THIS CONTINUES THE
STRETCH OF SUB-90 DEGREE DAYS AT 257 STRAIGHT AT KCHS AND 256
STRAIGHT AT KSAV DATING BACK TO EARLY SEPTEMBER 2012.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A SURFACE PRESSURE TROF WILL MOVE INTO THE CWA ON THURSDAY...WITH
MOIST SOUTHERLY WINDS AHEAD OF IT AND SOMEWHAT DRIER WESTERLY WINDS
BEHIND IT. THE TROF SHOULD BE ROUGHLY ALONG INTERSTATE 95 BY EARLY
AFTERNOON...AND AREAS ALONG AND EAST OF THE BOUNDARY WILL HAVE A
CHANCE OF SHOWERS AND THUNDERSTORMS AS DAYTIME HEATING CREATES SOME
SURFACE INSTABILITY AND CONVERGENCE. FURTHER WEST...ESPECIALLY OVER
OUR INTERIOR GEORGIA COUNTIES...THE ATMOSPHERE WILL BE DRIER AND
MORE STABLE...SO THERE WILL ONLY BE A SLIGHT CHANCE OF SHOWERS.
SKIES SHOULD AVERAGE OUT PARTLY CLOUDY...ALTHOUGH THERE WILL BE A
PERIOD OF MOSTLY CLOUDY SKIES TO THE EAST OF THE BOUNDARY DURING A
PORTION OF THE AFTERNOON.
THURSDAY NIGHT...THE INITIAL COOL FRONT PUSHES THROUGH THE
AREA...MOVING THE CHANCES FOR RAIN MOSTLY OFFSHORE...ALTHOUGH I
CANNOT RULE OUT A SLIGHT CHANCE OVER THE TRI COUNTY AREA AS THERE
MAY BE ENOUGH REMNANT MOISTURE WITH THE FRONT TO PROMOTE SOME
SHOWERS.
FRIDAY...THE WINDS WILL BE NORTHWEST BEHIND THE FRONT IN THE
MORNING...PROMOTING SOME DOWNSLOPE LOW LEVEL FLOW AND HEATING.
HOWEVER...DRIER AIR MOVING IN SHOULD PREVENT ANY RAIN...OR MUCH IN
THE WAY OF CLOUDS FOR THAT MATTER. A SECONDARY COLD FRONT WILL MOVE
THROUGH LATER IN THE DAY...CAUSING THE WINDS TO VEER TO NORTH AND
INCREASE AS COLD ADVECTION PICKS UP. FRIDAY NIGHT WILL BE MUCH
COOLER THAN THE PREVIOUS FEW.
SATURDAY...TEMPS WILL BEGIN WELL BELOW NORMAL AS MODIFIED AIR POURS
IN TO THE AREA...BUT THIS TIME OF YEAR THAT MEANS TEMPS MAINLY IN
THE 50S. PLENTY OF SUNSHINE WILL ALLOW AFTERNOON MAX TEMPS TO REACH
TO 80 OR ABOVE...BUT DEWPOINTS WILL DROP INTO THE 40S AWAY FROM THE
COAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
WHILE WE HAVE MAINTAINED PREVAILING VFR THROUGH 00Z FRIDAY...THERE
IS THE RISK OF MVFR CONDITIONS IN LIGHT FOG/STRATUS A FEW HOURS
EITHER SIDE OF DAYBREAK...AND ALSO MARGINAL MVFR CONDITIONS IN
ISOLATED TO SCATTERED SHRA/TSRA WITH A PRE-FRONTAL TROUGH IN THE
LATE MORNING THROUGH MID AFTERNOON. IF THE TROUGH IS QUICKER THAN
ANTICIPATED THERE COULD BE SOME GUSTY WINDS LATE IN THE TAF CYCLE.
EXTENDED AVIATION...VFR. WINDS COULD GET A BIT GUSTY FRIDAY AFTERNOON
BEHIND THE SECONDARY FRONT.
&&
.MARINE...
TONIGHT...THE SUB TROPICAL RIDGE IN THE ATLANTIC CENTERED OUT NEAR
32N AND 60W WILL START TO RELAX ITS GRIP ACROSS THE COASTAL WATERS
LATE...AS IT STARTS TO GIVE WAY TO AN UPSTREAM PRE-FRONTAL TROUGH.
THE PRESSURE GRADIENT WILL TEMPORARILY TIGHTEN A BIT BETWEEN THESE
TWO FEATURES...ALLOWING FOR SE AND SOUTH WINDS UP TO 15 KT THROUGH
ABOUT 06-08Z...BEFORE VEERING ABOUT 10-30 DEGREES AND DROPPING
OFF TO 10 OR LESS LATE. SEAS WON/T CHANGE MUCH...AVERAGING 2-4 FT
AND HIGHEST ACROSS THE OUTER GA WATERS. WE/LL NEED TO MONITOR FOR
SOME GUSTY SHOWERS/T-STORMS OVERNIGHT AS LOW LEVEL CONVERGENCE
INCREASES.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 230211
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1011 PM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
CLUSTER OF THUNDERSTORMS IN NORTH GEORGIA INTENSIFYING PAST COUPLE
OF HOURS IN AREA OF STRONG INSTABILITY. LIFT ENHANCED BY
APPROACHING SHORT WAVE TROUGH NOW MOVING INTO WESTERN GEORGIA.
CONVECTION MAY MOVE INTO WESTERN CSRA/PIEDMONT THIS EVENING. WILL
INCREASE POPS IN THAT AREA. DECREASED POPS ACROSS REST OF REGION
WITH LITTLE FORCING FOR CONVECTION THIS EVENING.
SKIES WILL BECOME MOSTLY CLOUDY TONIGHT WITH SOME LOW CLOUDS
EXPECTED. FRONT APPROACHING LATE CANT RULE OUT A SHOWERS LATE
TONIGHT...BUT SHOULD REMAIN ISOLATED. OVERNIGHT LOWS WILL
GENERALLY BE IN THE MID 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSING THE EASTERN CONUS DURING THE
SHORT TERM. THE AIR MASS WILL BE UNSTABLE WITH A PRE-FRONTAL TROUGH
OVER THE MIDLANDS. LOW LEVEL MOISTURE LINGERS WITH PRECIPITABLE
WATER RANGING FROM 1.00 T0 1.75 INCHES. THE THREAT OF CONVECTION
WILL CONTINUE WITH THE HIGHEST CHANCE ACROSS THE EAST MIDLANDS.
WILL RANGE POPS FROM NEAR 30 PERCENT CSRA TO 60 PERCENT NORTHEAST
ON THURSDAY. ALTHOUGH THE GFS IS SLIGHTLY FASTER...MODELS INDICATE
THE COLD FRONT CROSSING THE AREA THURSDAY NIGHT WITH THE CHANCE OF
CONVECTION ENDING. CUT POPS AFTER 18Z FROM PREVIOUS FORECAST BASED
ON LATEST MODEL TRENDS.
THE TEMPERATURE GUIDANCE WAS CLOSE WITH HIGHS IN THE MID/UPPER 80S
AND LOWS IN THE LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
THROUGH WEDNESDAY. GFS ENSEMBLE INCREASE POPS SLIGHTLY THROUGH THE
MIDDLE OF NEXT WEEK. WILL KEEP THE FORECAST DRY GIVEN INCREASING
H500 HEIGHTS AS THE UPPER RIDGE BUILDS.
EXPECT BELOW NORMAL TEMPERATURES DURING THE WEEKEND AND NEAR NORMAL
DURING THE REST OF THE MEDIUM RANGE PERIOD.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
RADAR CURRENTLY INDICATES CONVECTIVE ACTIVITY AT A MINIMUM ACROSS
OUR FA. MOST ACTIVITY CURRENTLY CONFINED TO THE UPSTATE
SC...STRETCHING SW ACROSS NE AND CENT GA. THIS ACTIVITY MOVING
SLOWLY TO THE ENE. LATEST HIGH RES MODELS SUGGEST THE ACTIVITY WILL
GRADUALLY WEAKEN AND DISSIPATE AS IT APPROACHES THE CSRA. FOR
NOW...NOT ENOUGH CONFIDENCE TO MENTION PRECIP IN AGS/DNL TAFS...BUT
WILL MONITOR.
GUIDANCE ALSO CONTINUING TO INDICATE CIG RESTRICTIONS LATE
TONIGHT/EARLY THURSDAY MORNING...IN A CONTINUED MOIST SOUTHERLY LOW
LEVEL FLOW. FOR NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL
MONITOR LATEST GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED.
UPPER IMPULSE AND SURFACE TROUGH WILL MOVE THROUGH
THURSDAY...POSSIBLY LEADING TO SCT SHRA/TSRA. CURRENT THINKING IS
THAT MOST OF THE ACTIVITY THURSDAY WILL BE EAST OF THE TERMINALS.
WILL NOT MENTION IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 230201
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1000 PM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
THERE ARE SOME CHANGES THAT WILL TAKE PLACE IN THE LARGER
SCALE...AS THE FIRST SHORT WAVE OFF THE EASTERN FLORIDA COAST WILL
GET LIFTED NE AS THE NEXT LONG WAVE TROUGH IN THE MISSISSIPPI
VALLEY SHIFTS EAST. AS THIS TRANSPIRES...IT FORCES THE LAST GRIPS
OF THE ATLANTIC RIDGE TO PULL OFFSHORE AFTER MIDNIGHT...AS A PRE-
FRONTAL TROUGH IN WESTERN GEORGIA APPROACHES LATE. THE FORECAST
AREA WILL THEN LIE SANDWICHED BETWEEN THE FIRST SHORT WAVE IN THE
NEARBY ATLANTIC AND THE SECOND IMPULSE AND ITS REFLECTION AT THAT
SURFACE. WHILE THERE IS SOME INCREASE IN LOW LEVEL CONVERGENCE TO
THE EAST...THE SYNOPTIC FLOW MAY VEER TOO FAR TO THE SW TO ALLOW
FOR ANYTHING MORE THAN LOW END POPS OVER CHARLESTON COUNTY CLOSE
TO DAYBREAK. UPSTREAM IT APPEARS THAT THE BEST FORCING WILL STAY
TO THE WEST...BUT A FEW SHOWERS OR T-STORMS COULD SNEAK INTO THE SW
CORNER LATE. FOR NOW WE HAVE SHOWN POPS AT 14 PERCENT OR LESS FOR
ALL BUT NORTHERN CHARLESTON COUNTY AND CANDLER AND JEKINS WHERE 20
POPS WILL BE SUFFICIENT.
WHILE CONDITIONS ARE NOT AS FAVORABLE FOR FOG DEVELOPMENT AS LAST
NIGHT /IE. TOO MUCH WIND IN THE BOUNDARY LAYER UNTIL LATE AND
MUCH LESS RAINFALL/...WE HAVE MAINTAINED MENTION OF PATCHY FOG TO
OUR NW TIER WHERE THEY HAVE A BETTER CHANCE OF ACHIEVING THEIR
CROSS-OVER TEMPS AND FOG STABILITY INDICES ARE IN THE LOWER 20S.
THE MIXING IN THE BOUNDARY LAYER AND AN INCREASE IN CLOUD COVER
WILL LIMIT TEMPS TO ONLY THE MID AND UPPER 60S INLAND FROM THE
SLIGHTLY WARMER BEACHES.
FOR THOSE THAT ARE INTERESTED...TEMPS AGAIN FAILED TO HIT 90
DEGREES AT BOTH KCHS AND KSAV WEDNESDAY. THIS CONTINUES THE
STRETCH OF SUB-90 DEGREE DAYS AT 257 STRAIGHT AT KCHS AND 256
STRAIGHT AT KSAV DATING BACK TO EARLY SEPTEMBER 2012.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A SURFACE PRESSURE TROF WILL MOVE INTO THE CWA ON THURSDAY...WITH
MOIST SOUTHERLY WINDS AHEAD OF IT AND SOMEWHAT DRIER WESTERLY WINDS
BEHIND IT. THE TROF SHOULD BE ROUGHLY ALONG INTERSTATE 95 BY EARLY
AFTERNOON...AND AREAS ALONG AND EAST OF THE BOUNDARY WILL HAVE A
CHANCE OF SHOWERS AND THUNDERSTORMS AS DAYTIME HEATING CREATES SOME
SURFACE INSTABILITY AND CONVERGENCE. FURTHER WEST...ESPECIALLY OVER
OUR INTERIOR GEORGIA COUNTIES...THE ATMOSPHERE WILL BE DRIER AND
MORE STABLE...SO THERE WILL ONLY BE A SLIGHT CHANCE OF SHOWERS.
SKIES SHOULD AVERAGE OUT PARTLY CLOUDY...ALTHOUGH THERE WILL BE A
PERIOD OF MOSTLY CLOUDY SKIES TO THE EAST OF THE BOUNDARY DURING A
PORTION OF THE AFTERNOON.
THURSDAY NIGHT...THE INITIAL COOL FRONT PUSHES THROUGH THE
AREA...MOVING THE CHANCES FOR RAIN MOSTLY OFFSHORE...ALTHOUGH I
CANNOT RULE OUT A SLIGHT CHANCE OVER THE TRI COUNTY AREA AS THERE
MAY BE ENOUGH REMNANT MOISTURE WITH THE FRONT TO PROMOTE SOME
SHOWERS.
FRIDAY...THE WINDS WILL BE NORTHWEST BEHIND THE FRONT IN THE
MORNING...PROMOTING SOME DOWNSLOPE LOW LEVEL FLOW AND HEATING.
HOWEVER...DRIER AIR MOVING IN SHOULD PREVENT ANY RAIN...OR MUCH IN
THE WAY OF CLOUDS FOR THAT MATTER. A SECONDARY COLD FRONT WILL MOVE
THROUGH LATER IN THE DAY...CAUSING THE WINDS TO VEER TO NORTH AND
INCREASE AS COLD ADVECTION PICKS UP. FRIDAY NIGHT WILL BE MUCH
COOLER THAN THE PREVIOUS FEW.
SATURDAY...TEMPS WILL BEGIN WELL BELOW NORMAL AS MODIFIED AIR POURS
IN TO THE AREA...BUT THIS TIME OF YEAR THAT MEANS TEMPS MAINLY IN
THE 50S. PLENTY OF SUNSHINE WILL ALLOW AFTERNOON MAX TEMPS TO REACH
TO 80 OR ABOVE...BUT DEWPOINTS WILL DROP INTO THE 40S AWAY FROM THE
COAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
WHILE WE HAVE MAINTAINED PREVAILING VFR THROUGH 00Z FRIDAY...THERE
IS THE RISK OF MVFR CONDITIONS IN LIGHT FOG/STRATUS A FEW HOURS
EITHER SIDE OF DAYBREAK...AND ALSO MARGINAL MVFR CONDITIONS IN
ISOLATED TO SCATTERED SHRA/TSRA WITH A PRE-FRONTAL TROUGH IN THE
LATE MORNING THROUGH MID AFTERNOON. IF THE TROUGH IS QUICKER THAN
ANTICIPATED THERE COULD BE SOME GUSTY WINDS LATE IN THE TAF CYCLE.
EXTENDED AVIATION...VFR. WINDS COULD GET A BIT GUSTY FRIDAY AFTERNOON
BEHIND THE SECONDARY FRONT.
&&
.MARINE...
TONIGHT...THE SUB TROPICAL RIDGE IN THE ATLANTIC CENTERED OUT NEAR
32N AND 60W WILL START TO RELAX ITS GRIP ACROSS THE COASTAL WATERS
LATE...AS IT STARTS TO GIVE WAY TO AN UPSTREAM PRE-FRONTAL TROUGH.
THE PRESSURE GRADIENT WILL TEMPORARILY TIGHTEN A BIT BETWEEN THESE
TWO FEATURES...ALLOWING FOR SE AND SOUTH WINDS UP TO 15 KT THROUGH
ABOUT 06-08Z...BEFORE VEERING ABOUT 10-30 DEGREES AND DROPPING
OFF TO 10 OR LESS LATE. SEAS WON/T CHANGE MUCH...AVERAGING 2-4 FT
AND HIGHEST ACROSS THE OUTER GA WATERS. WE/LL NEED TO MONITOR FOR
SOME GUSTY SHOWERS/T-STORMS OVERNIGHT AS LOW LEVEL CONVERGENCE
INCREASES.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
000
FXUS62 KCHS 230151
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
951 PM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
THERE ARE SOME CHANGES THAT WILL TAKE PLACE IN THE LARGER
SCALE...AS THE FIRST SHORT WAVE OFF THE EASTERN FLORIDA COAST WILL
GET LIFTED NE AS THE NEXT LONG WAVE TROUGH IN THE MISSISSIPPI
VALLEY SHIFTS EAST. AS THIS TRANSPIRES...IT FORCES THE LAST GRIPS
OF THE ATLANTIC RIDGE TO PULL OFFSHORE AFTER MIDNIGHT...AS A PRE-
FRONTAL TROUGH IN WESTERN GEORGIA APPROACHES LATE. THE FORECAST
AREA WILL THEN LIE SANDWICHED BETWEEN THE FIRST SHORT WAVE IN THE
NEARBY ATLANTIC AND THE SECOND IMPULSE AND ITS REFLECTION AT THAT
SURFACE. WHILE THERE IS SOME INCREASE IN LOW LEVEL CONVERGENCE TO
THE EAST...THE SYNOPTIC FLOW MAY VEER TOO FAR TO THE SW TO ALLOW
FOR ANYTHING MORE THAN LOW END POPS OVER CHARLESTON COUNTY CLOSE
TO DAYBREAK. UPSTREAM IT APPEARS THAT THE BEST FORCING WILL STAY
TO THE WEST...BUT A FEW SHOWERS OR T-STORMS COULD SNEAK INTO THE
SW CORNER LATE. FOR NOW WE HAVE SHOWN POPS AT 14 PERCENT OR LESS.
WHILE CONDITIONS ARE NOT AS FAVORABLE FOR FOG DEVELOPMENT AS LAST
NIGHT /IE. TOO MUCH WIND IN THE BOUNDARY LAYER UNTIL LATE AND
MUCH LESS RAINFALL/...WE HAVE MAINTAINED MENTION OF PATCHY FOG TO
OUR NW TIER WHERE THEY HAVE A BETTER CHANCE OF ACHIEVING THEIR
CROSS-OVER TEMPS AND FOG STABILITY INDICES ARE IN THE LOWER 20S.
THE MIXING IN THE BOUNDARY LAYER AND AN INCREASE IN CLOUD COVER
WILL LIMIT TEMPS TO ONLY THE MID AND UPPER 60S INLAND FROM THE
SLIGHTLY WARMER BEACHES.
FOR THOSE THAT ARE INTERESTED...TEMPS AGAIN FAILED TO HIT 90
DEGREES AT BOTH KCHS AND KSAV WEDNESDAY. THIS CONTINUES THE
STRETCH OF SUB-90 DEGREE DAYS AT 257 STRAIGHT AT KCHS AND 256
STRAIGHT AT KSAV DATING BACK TO EARLY SEPTEMBER 2012.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A SURFACE PRESSURE TROF WILL MOVE INTO THE CWA ON THURSDAY...WITH
MOIST SOUTHERLY WINDS AHEAD OF IT AND SOMEWHAT DRIER WESTERLY WINDS
BEHIND IT. THE TROF SHOULD BE ROUGHLY ALONG INTERSTATE 95 BY EARLY
AFTERNOON...AND AREAS ALONG AND EAST OF THE BOUNDARY WILL HAVE A
CHANCE OF SHOWERS AND THUNDERSTORMS AS DAYTIME HEATING CREATES SOME
SURFACE INSTABILITY AND CONVERGENCE. FURTHER WEST...ESPECIALLY OVER
OUR INTERIOR GEORGIA COUNTIES...THE ATMOSPHERE WILL BE DRIER AND
MORE STABLE...SO THERE WILL ONLY BE A SLIGHT CHANCE OF SHOWERS.
SKIES SHOULD AVERAGE OUT PARTLY CLOUDY...ALTHOUGH THERE WILL BE A
PERIOD OF MOSTLY CLOUDY SKIES TO THE EAST OF THE BOUNDARY DURING A
PORTION OF THE AFTERNOON.
THURSDAY NIGHT...THE INITIAL COOL FRONT PUSHES THROUGH THE
AREA...MOVING THE CHANCES FOR RAIN MOSTLY OFFSHORE...ALTHOUGH I
CANNOT RULE OUT A SLIGHT CHANCE OVER THE TRI COUNTY AREA AS THERE
MAY BE ENOUGH REMNANT MOISTURE WITH THE FRONT TO PROMOTE SOME
SHOWERS.
FRIDAY...THE WINDS WILL BE NORTHWEST BEHIND THE FRONT IN THE
MORNING...PROMOTING SOME DOWNSLOPE LOW LEVEL FLOW AND HEATING.
HOWEVER...DRIER AIR MOVING IN SHOULD PREVENT ANY RAIN...OR MUCH IN
THE WAY OF CLOUDS FOR THAT MATTER. A SECONDARY COLD FRONT WILL MOVE
THROUGH LATER IN THE DAY...CAUSING THE WINDS TO VEER TO NORTH AND
INCREASE AS COLD ADVECTION PICKS UP. FRIDAY NIGHT WILL BE MUCH
COOLER THAN THE PREVIOUS FEW.
SATURDAY...TEMPS WILL BEGIN WELL BELOW NORMAL AS MODIFIED AIR POURS
IN TO THE AREA...BUT THIS TIME OF YEAR THAT MEANS TEMPS MAINLY IN
THE 50S. PLENTY OF SUNSHINE WILL ALLOW AFTERNOON MAX TEMPS TO REACH
TO 80 OR ABOVE...BUT DEWPOINTS WILL DROP INTO THE 40S AWAY FROM THE
COAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
WHILE WE HAVE MAINTAINED PREVAILING VFR THROUGH 00Z FRIDAY...THERE
IS THE RISK OF MVFR CONDITIONS IN LIGHT FOG/STRATUS A FEW HOURS
EITHER SIDE OF DAYBREAK...AND ALSO MARGINAL MVFR CONDITIONS IN
ISOLATED TO SCATTERED SHRA/TSRA WITH A PRE-FRONTAL TROUGH IN THE
LATE MORNING THROUGH MID AFTERNOON. IF THE TROUGH IS QUICKER THAN
ANTICIPATED THERE COULD BE SOME GUSTY WINDS LATE IN THE TAF CYCLE.
EXTENDED AVIATION...VFR. WINDS COULD GET A BIT GUSTY FRIDAY AFTERNOON
BEHIND THE SECONDARY FRONT.
&&
.MARINE...
TONIGHT...THE SUB TROPICAL RIDGE IN THE ATLANTIC CENTERED OUT NEAR
32N AND 60W WILL START TO RELAX ITS GRIP ACROSS THE COASTAL WATERS
LATE...AS IT STARTS TO GIVE WAY TO AN UPSTREAM PRE-FRONTAL TROUGH.
THE PRESSURE GRADIENT WILL TEMPORARILY TIGHTEN A BIT BETWEEN THESE
TWO FEATURES...ALLOWING FOR SE AND SOUTH WINDS UP TO 15 KT THROUGH
ABOUT 06-08Z...BEFORE VEERING ABOUT 10-30 DEGREES AND DROPPING
OFF TO 10 OR LESS LATE. SEAS WON/T CHANGE MUCH...AVERAGING 2-4 FT
AND HIGHEST ACROSS THE OUTER GA WATERS. WE/LL NEED TO MONITOR FOR
SOME GUSTY SHOWERS/T-STORMS OVERNIGHT AS LOW LEVEL CONVERGENCE
INCREASES.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 230022
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
822 PM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
CLUSTER OF THUNDERSTORMS IN NORTH GEORGIA INTENSIFYING PAST COUPLE
OF HOURS IN AREA OF STRONG INSTABILITY. LIFT ENHANCED BY
APPROACHING SHORT WAVE TROUGH NOW MOVING INTO WESTERN GEORGIA.
CONVECTION MAY MOVE INTO WESTERN CSRA/PIEDMONT THIS EVENING. WILL
INCREASE POPS IN THAT AREA. DECREASED POPS ACROSS REST OF REGION
WITH LITTLE FORCING FOR CONVECTION THIS EVENING.
SKIES WILL BECOME MOSTLY CLOUDY TONIGHT WITH SOME LOW CLOUDS
EXPECTED. FRONT APPROACHING LATE CANT RULE OUT A SHOWERS LATE
TONIGHT...BUT SHOULD REMAIN ISOLATED. OVERNIGHT LOWS WILL
GENERALLY BE IN THE MID 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSING THE EASTERN CONUS DURING THE
SHORT TERM. THE AIR MASS WILL BE UNSTABLE WITH A PRE-FRONTAL TROUGH
OVER THE MIDLANDS. LOW LEVEL MOISTURE LINGERS WITH PRECIPITABLE
WATER RANGING FROM 1.00 T0 1.75 INCHES. THE THREAT OF CONVECTION
WILL CONTINUE WITH THE HIGHEST CHANCE ACROSS THE EAST MIDLANDS.
WILL RANGE POPS FROM NEAR 30 PERCENT CSRA TO 60 PERCENT NORTHEAST
ON THURSDAY. ALTHOUGH THE GFS IS SLIGHTLY FASTER...MODELS INDICATE
THE COLD FRONT CROSSING THE AREA THURSDAY NIGHT WITH THE CHANCE OF
CONVECTION ENDING. CUT POPS AFTER 18Z FROM PREVIOUS FORECAST BASED
ON LATEST MODEL TRENDS.
THE TEMPERATURE GUIDANCE WAS CLOSE WITH HIGHS IN THE MID/UPPER 80S
AND LOWS IN THE LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
THROUGH WEDNESDAY. GFS ENSEMBLE INCREASE POPS SLIGHTLY THROUGH THE
MIDDLE OF NEXT WEEK. WILL KEEP THE FORECAST DRY GIVEN INCREASING
H500 HEIGHTS AS THE UPPER RIDGE BUILDS.
EXPECT BELOW NORMAL TEMPERATURES DURING THE WEEKEND AND NEAR NORMAL
DURING THE REST OF THE MEDIUM RANGE PERIOD.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
RADAR INDICATES CONVECTIVE ACTIVITY AT A MINIMUM ACROSS OUR FA. MOST
ACTIVITY CURRENTLY CONFINED TO THE UPSTATE SC AND N/CENT GA. HIGH
RES MODELS INDICATE ACTIVITY DEVELOPING TO OUR WEST NEAR AN UPPER
IMPULSE AND SURFACE TROUGH...WEAKENING AS IT MOVES EAST AND
APPROACHES THE FA LATE TONIGHT. GUIDANCE INDICATING CIG RESTRICTIONS
LATE TONIGHT...IN A CONTINUED MOIST SOUTHERLY LOW LEVEL FLOW. FOR
NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL MONITOR LATEST
GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED. UPPER IMPULSE
AND SURFACE TROUGH WILL MOVE THROUGH THURSDAY...POSSIBLY LEADING
TO SCT SHRA/TSRA...BUT CHANCES TOO LOW...ALONG WITH SOME TIMING
QUESTIONS...TO INCLUDE MENTION IN THE TAF AT THIS TIME.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KFFC 222353 AAA
AFDFFC
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
753 PM EDT WED MAY 22 2013
.UPDATE...
QUICK UPDATE TO GRIDS. APPEARS COVERAGE OF TSRA OVER ERN AL AND
WRN GA LOWER THAN MODEL FCSTS. WILL BACK OFF ON POPS. MLCAPE
PRETTY STOUT WITH VALUES 1500-2000 J/KG AND 0-6KM BULK SHEAR
AROUND 20-30KTS. APPARENTLY FORCING AND LOCALIZED LIFT IS LACKING.
WILL CONTINUE TO MONITOR.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 350 PM EDT WED MAY 22 2013/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AFTERNOON CONVECTION EXPECTED TO INCREASE IN COVERAGE AND PERSIST
INTO THE EVENING AND OVERNIGHT HOURS AS UPPER LEVEL TROUGH MOVES
THROUGH THE MISSISSIPPI VALLEY. CONVECTION EXPECTED TO BECOME MORE
ORGANIZED AS ASSOCIATED SHORT WAVE FOCUSES DEVELOPMENT. MODELS A
LITTLE INCONSISTENT WITH THE DEVELOPMENT AND/OR PROGRESSION OF THE
ORGANIZED PRECIPITATION...BUT WITH INCREASING
INSTABILITIES...DIURNAL HEATING...AND INCREASING SHEAR ACROSS THE
AREA...FEEL THERE IS ENOUGH TO SUPPORT GOOD CHANCE TO LIKELY
POPS...ESPECIALLY ACROSS NORTH GEORGIA. HAVE CONTINUED MENTION OF
POSSIBLE SEVERE STORMS...ACCOMPANIED WITH GUSTY WINDS AND SMALL
HAIL...IN THE GRIDS THROUGH 02Z TONIGHT ACROSS NORTH
GEORGIA...GENERALLY NORTH OF THE ATL METRO AREA. HAVE ALSO
QUICKLY TAPERED OFF EVENING AND OVERNIGHT POPS INTO THURSDAY
MORNING...WITH GENERALLY SLIGHT CHANCE POPS ACROSS THE AREA THROUGH
THE DAY THURSDAY AS SHORT WAVE PUSHES INTO THE CAROLINAS.
AS PREVIOUSLY MENTIONED...THE SEVERE THREAT IS PRIMARILY CONFINED TO
NORTH GEORGIA...THOUGH STRONG STORMS CAN BE EXPECTED ACROSS MUCH OF
THE CWA. THE PRIMARY CONCERNS IN SEVERE ACTIVITY WILL BE GUSTY WINDS
TO 60 MPH OR HIGHER...1 INCH HAIL OR HIGHER...FREQUENT LIGHTNING AND
PERIODS OF HEAVY RAINFALL. GUSTY WINDS AND SMALL HAIL ARE ALSO
POSSIBLE IN THE STRONGER STORMS.
PRESSURE GRADIENT TIGHTENS THURSDAY AFTERNOON AND INTO FRIDAY...WITH
WINDS 10 TO 15 MPH WITH GUSTS NEAR 20 MPH...ESPECIALLY ACROSS NORTHERN
AND EASTERN GEORGIA.
FOR THE TEMPERATURES..HAVE GENERALLY GONE WITH A GUIDANCE BLEND.
TEMPERATURES THURSDAY MORNING ARE EXPECTED TO BE IN THE 60S...AND
DEPENDING ON THE TIMING OF THE DIMINISHING CONVECTION AND CLOUDS OUT
OF THE AREA...THIS COULD IMPACT MORNING LOWS BY A FEW DEGREES.
TEMPERATURES WILL BE BACK IN THE LOW TO MID 80S THURSDAY AFTERNOON
BEFORE COOLING BY FRIDAY.
31
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED PORTION OF THE FORECAST. A MUCH
DRIER AIRMASS MOVES OVER THE AREA FRIDAY WITH DRY NW FLOW ALOFT
AND SURFACE HIGH PRESSURE BUILDING OVER THE OH/TN VALLEYS DURING
THE DAY. GRADIENT WINDS WILL INCREASE GETTING CLOSE TO WIND
ADVISORY CRITERIA(20 MPH SUSTAINED) FOR SOME AREAS. DRY CONDITIONS
SHOULD CONTINUE THROUGH THE WEEKEND EVEN WITH SLIGHT DIFFERENCES
BETWEEN THE GFS AND ECMWF. THE NW FLOW ALOFT N OF THE AREA IS
EXPECTED TO BECOME MORE ACTIVE WITH INCREASED PRECIP CHANCES NORTH
OF THE STATE...BUT IT SHOULD STAY DRY ACROSS GA. LOOKS LIKE THE
BETTER MOISTURE FINALLY MOVES IN ACROSS THE AREA BY THE BEGINNING
OF NEXT WEEK SO WILL SLOWLY INCREASE CHANCES OF POPS MON THROUGH DAY
7. TEMPERATURES GENERALLY RUNNING WITHIN 5 DEGREES OF NORMAL
THROUGH THE PERIOD EXCEPT SATURDAY ND SUNDAY MORNING LOWS ARE
RUNNING 10-15 DEGREES BELOW NORMAL.
01
&&
.AVIATION...
00Z UPDATE...
CONFIDENCE ON WIDESPREAD TSRA DROPPING OVER MUCH OF THE AREA. WILL
CONTINUE TEMPO TSRA BUT BASED ON TRENDS...MAY HAVE TO PULL THIS
OUT LATER THIS EVENING. ANY PRECIP SHOULD END OR BE EAST OF FCST
POINTS BY 06Z. WINDS WILL SHIFT TO WEST AFTER 07Z AND NW AFTER
SUNRISE. NOT MUCH CHANCE FOR RADIATIONAL FOG UNLESS PRECIP BECOMES
MORE WIDESPREAD. HAVE BACKED OFF ON FOG FOR MOST SITES. COULD SEE
SOME GUSTS TO 25KTS THURS AFTERNOON WITH GOOD VERTICAL MIXING.
//ATL CONFIDENCE...00Z UPDATE...
LOW CONFIDENCE ON LIKELIHOOD OF TSRA THIS EVENING.
LOW CONFIDENCE ON RADIATIONAL FOG THURS MORNING.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 85 59 79 / 60 20 5 0
ATLANTA 66 83 59 76 / 70 10 5 0
BLAIRSVILLE 61 78 54 71 / 70 20 10 0
CARTERSVILLE 64 83 57 76 / 70 10 5 0
COLUMBUS 68 89 63 82 / 70 10 5 0
GAINESVILLE 64 82 57 75 / 70 10 5 0
MACON 66 89 60 83 / 60 20 5 0
ROME 64 84 57 77 / 50 10 5 0
PEACHTREE CITY 64 85 58 77 / 70 10 5 0
VIDALIA 68 89 65 88 / 40 20 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...SNELSON
000
FXUS62 KCHS 222339
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
734 PM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
QUITE A CHANGE IN THE PATTERN SINCE YESTERDAY...WITH MUCH OF THE
AREA VOID OF ANY CONVECTION EARLIER TODAY. WE/RE FINISHED FOR THE
EVENING FOR ANY SHOWERS OR T-STORMS IN THE LOCAL ZONES...WITH THE
SEA BREEZE HAVING CLEARED OUR NW TIER. IN ITS WAKE A STABILIZED
ENVIRONMENT HAS ENSUED AND WILL PERSIST.
FOR TONIGHT... THERE IS SOME CHANGES THAT WILL TAKE PLACE IN THE
LARGER SCALE...AS THE FIRST SHORT WAVE OFF THE EASTERN FLORIDA COAST
TO GET LIFTED NE AS THE NEXT LONG WAVE TROUGH IN THE MISSISSIPPI
VALLEY SHIFTS EAST. AS THIS TRANSPIRES...IT FORCES THE LAST GRIPS OF
THE ATLANTIC RIDGE TO PULL OFFSHORE AFTER MIDNIGHT...AS A
PRE-FRONTAL TROUGH IN EASTERN ALABAMA AND WESTERN GEORGIA APPROACHES
LATE. THE FORECAST AREA WILL THEN LIE SANDWICHED BETWEEN THE FIRST
SHORT WAVE IN THE NEARBY ATLANTIC AND THE SECOND IMPULSE AND ITS
REFLECTION AT THAT SURFACE. WHILE THERE IS SOME INCREASE IN LOW
LEVEL CONVERGENCE TO THE EAST...THE SYNOPTIC FLOW MAY VEER TOO FAR
TO THE SW TO ALLOW FOR ANYTHING MORE THAN LOW END POPS OVER
CHARLESTON COUNTY CLOSE TO DAYBREAK. UPSTREAM IT APPEARS THAT THE
BEST FORCING WILL STAY TO THE WEST...SO LESS THAN 14 POPS HAVE BEEN
FORECAST ELSEWHERE.
WHILE CONDITIONS ARE NOT AS FAVORABLE FOR FOG DEVELOPMENT AS LAST
NIGHT /IE. TOO MUCH WIND IN THE BOUNDARY LAYER UNTIL LATE AND
MUCH LESS RAINFALL/...WE HAVE OPTED TO ADD PATCHY FOG TO OUR NW
TIER WHERE THEY HAVE A BETTER CHANCE OF ACHIEVING THEIR CROSS-OVER
TEMPS AND FOG STABILITY INDICES ARE IN THE LOWER 20S.
THE MIXING IN THE BOUNDARY LAYER AND AN INCREASE IN CLOUD COVER
WILL LIMIT TEMPS TO ONLY THE MID AND UPPER 60S INLAND FROM THE
SLIGHTLY WARMER BEACHES.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A SURFACE PRESSURE TROF WILL MOVE INTO THE CWA ON THURSDAY...WITH
MOIST SOUTHERLY WINDS AHEAD OF IT AND SOMEWHAT DRIER WESTERLY WINDS
BEHIND IT. THE TROF SHOULD BE ROUGHLY ALONG INTERSTATE 95 BY EARLY
AFTERNOON...AND AREAS ALONG AND EAST OF THE BOUNDARY WILL HAVE A
CHANCE OF SHOWERS AND THUNDERSTORMS AS DAYTIME HEATING CREATES SOME
SURFACE INSTABILITY AND CONVERGENCE. FURTHER WEST...ESPECIALLY OVER
OUR INTERIOR GEORGIA COUNTIES...THE ATMOSPHERE WILL BE DRIER AND
MORE STABLE...SO THERE WILL ONLY BE A SLIGHT CHANCE OF SHOWERS.
SKIES SHOULD AVERAGE OUT PARTLY CLOUDY...ALTHOUGH THERE WILL BE A
PERIOD OF MOSTLY CLOUDY SKIES TO THE EAST OF THE BOUNDARY DURING A
PORTION OF THE AFTERNOON.
THURSDAY NIGHT...THE INITIAL COOL FRONT PUSHES THROUGH THE
AREA...MOVING THE CHANCES FOR RAIN MOSTLY OFFSHORE...ALTHOUGH I
CANNOT RULE OUT A SLIGHT CHANCE OVER THE TRI COUNTY AREA AS THERE
MAY BE ENOUGH REMNANT MOISTURE WITH THE FRONT TO PROMOTE SOME
SHOWERS.
FRIDAY...THE WINDS WILL BE NORTHWEST BEHIND THE FRONT IN THE
MORNING...PROMOTING SOME DOWNSLOPE LOW LEVEL FLOW AND HEATING.
HOWEVER...DRIER AIR MOVING IN SHOULD PREVENT ANY RAIN...OR MUCH IN
THE WAY OF CLOUDS FOR THAT MATTER. A SECONDARY COLD FRONT WILL MOVE
THROUGH LATER IN THE DAY...CAUSING THE WINDS TO VEER TO NORTH AND
INCREASE AS COLD ADVECTION PICKS UP. FRIDAY NIGHT WILL BE MUCH
COOLER THAN THE PREVIOUS FEW.
SATURDAY...TEMPS WILL BEGIN WELL BELOW NORMAL AS MODIFIED AIR POURS
IN TO THE AREA...BUT THIS TIME OF YEAR THAT MEANS TEMPS MAINLY IN
THE 50S. PLENTY OF SUNSHINE WILL ALLOW AFTERNOON MAX TEMPS TO REACH
TO 80 OR ABOVE...BUT DEWPOINTS WILL DROP INTO THE 40S AWAY FROM THE
COAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
WHILE WE HAVE MAINTAINED PREVAILING VFR THROUGH 00Z FRIDAY...THERE
IS THE RISK OF MVFR CONDITIONS IN LIGHT FOG/STRATUS A FEW HOURS
EITHER SIDE OF DAYBREAK...AND ALSO MARGINAL MVFR CONDITIONS IN
ISOLATED TO SCATTERED SHRA/TSRA WITH A PRE-FRONTAL TROUGH IN THE
LATE MORNING THROUGH MID AFTERNOON. IF THE TROUGH IS QUICKER THAN
ANTICIPATED THERE COULD BE SOME GUSTY WINDS LATE IN THE TAF CYCLE.
EXTENDED AVIATION...VFR. WINDS COULD GET A BIT GUSTY FRIDAY AFTERNOON
BEHIND THE SECONDARY FRONT.
&&
.MARINE...
TONIGHT...THE SUB TROPICAL RIDGE IN THE ATLANTIC CENTERED OUT NEAR
32N AND 60W WILL START TO RELAX ITS GRIP ACROSS THE COASTAL WATERS
LATE...AS IT STARTS TO GIVE WAY TO AN UPSTREAM PRE-FRONTAL TROUGH.
THE PRESSURE GRADIENT WILL TEMPORARILY TIGHTEN A BIT BETWEEN THESE
TWO FEATURES...ALLOWING FOR SE AND SOUTH WINDS UP TO 15 KT THROUGH
ABOUT 06-08Z...BEFORE DROPPING OFF TO 10 OR LESS LATE. SEAS WON/T
CHANGE MUCH...AVERAGING 2-4 FT AND HIGHEST ACROSS THE OUTER GA
WATERS. WE/LL NEED TO MONITOR FOR SOME GUSTY SHOWERS/T-STORMS
OVERNIGHT AS LOW LEVEL CONVERGENCE INCREASES.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
000
FXUS62 KCHS 222334
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
734 PM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
QUITE A CHANGE IN THE PATTERN SINCE YESTERDAY...WITH MUCH OF THE
AREA VOID OF ANY CONVECTION EARLIER TODAY. WE/RE FINISHED FOR THE
EVENING FOR ANY SHOWERS OR T-STORMS IN THE LOCAL ZONES...WITH THE
SEA BREEZE HAVING CLEARED OUR NW TIER. IN ITS WAKE A STABILIZED
ENVIRONMENT HAS ENSUED AND WILL PERSIST.
FOR TONIGHT... THERE IS SOME CHANGES THAT WILL TAKE PLACE IN THE
LARGER SCALE,,,AS THE FIRST SHORT WAVE OFF THE EASTERN FLORIDA
COAST TO GET LIFTED NE AS THE NEXT LONG WAVE TROUGH IN THE
MISSISSIPPI VALLEY SHIFTS EAST. AS THIS TRANSPIRES...IT FORCES
THE LAST GRIPS OF THE ATLANTIC RIDGE TO PULL OFFSHORE AFTER
MIDNIGHT...AS A PRE-FRONTAL TROUGH IN EASTERN ALABAMA AND WESTERN
GEORGIA APPROACHES LATE. THE FORECAST AREA WILL THEN LIE
SANDWICHED BETWEEN THE FIRST SHORT WAVE IN THE NEARBY ATLANTIC AND
THE SECOND IMPULSE AND ITS REFLECTION AT THAT SURFACE. WHILE THERE
IS SOME INCREASE IN LOW LEVEL CONVERGENCE TO THE EAST...THE
SYNOPTIC FLOW MAY VEER TOO FAR TO THE SW TO ALLOW FOR ANYTHING
MORE THAN LOW END POPS OVER CHARLESTON COUNTY CLOSE TO DAYBREAK.
UPSTREAM IT APPEARS THAT THE BEST FORCING WILL STAY TO THE
WEST...SO LESS THAN 14 POPS HAVE BEEN FORECAST ELSEWHERE.
WHILE CONDITIONS ARE NOT AS FAVORABLE FOR FOG DEVELOPMENT AS LAST
NIGHT /IE. TOO MUCH WIND IN THE BOUNDARY LAYER UNTIL LATE AND
MUCH LESS RAINFALL/...WE HAVE OPTED TO ADD PATCHY FOG TO OUR NW
TIER WHERE THEY HAVE A BETTER CHANCE OF ACHIEVING THEIR CROSS-OVER
TEMPS AND FOG STABILITY INDICES ARE IN THE LOWER 20S.
THE MIXING IN THE BOUNDARY LAYER AND AN INCREASE IN CLOUD COVER
WILL LIMIT TEMPS TO ONLY THE MID AND UPPER 60S INLAND FROM THE
SLIGHTLY WARMER BEACHES.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A SURFACE PRESSURE TROF WILL MOVE INTO THE CWA ON THURSDAY...WITH
MOIST SOUTHERLY WINDS AHEAD OF IT AND SOMEWHAT DRIER WESTERLY WINDS
BEHIND IT. THE TROF SHOULD BE ROUGHLY ALONG INTERSTATE 95 BY EARLY
AFTERNOON...AND AREAS ALONG AND EAST OF THE BOUNDARY WILL HAVE A
CHANCE OF SHOWERS AND THUNDERSTORMS AS DAYTIME HEATING CREATES SOME
SURFACE INSTABILITY AND CONVERGENCE. FURTHER WEST...ESPECIALLY OVER
OUR INTERIOR GEORGIA COUNTIES...THE ATMOSPHERE WILL BE DRIER AND
MORE STABLE...SO THERE WILL ONLY BE A SLIGHT CHANCE OF SHOWERS.
SKIES SHOULD AVERAGE OUT PARTLY CLOUDY...ALTHOUGH THERE WILL BE A
PERIOD OF MOSTLY CLOUDY SKIES TO THE EAST OF THE BOUNDARY DURING A
PORTION OF THE AFTERNOON.
THURSDAY NIGHT...THE INITIAL COOL FRONT PUSHES THROUGH THE
AREA...MOVING THE CHANCES FOR RAIN MOSTLY OFFSHORE...ALTHOUGH I
CANNOT RULE OUT A SLIGHT CHANCE OVER THE TRI COUNTY AREA AS THERE
MAY BE ENOUGH REMNANT MOISTURE WITH THE FRONT TO PROMOTE SOME
SHOWERS.
FRIDAY...THE WINDS WILL BE NORTHWEST BEHIND THE FRONT IN THE
MORNING...PROMOTING SOME DOWNSLOPE LOW LEVEL FLOW AND HEATING.
HOWEVER...DRIER AIR MOVING IN SHOULD PREVENT ANY RAIN...OR MUCH IN
THE WAY OF CLOUDS FOR THAT MATTER. A SECONDARY COLD FRONT WILL MOVE
THROUGH LATER IN THE DAY...CAUSING THE WINDS TO VEER TO NORTH AND
INCREASE AS COLD ADVECTION PICKS UP. FRIDAY NIGHT WILL BE MUCH
COOLER THAN THE PREVIOUS FEW.
SATURDAY...TEMPS WILL BEGIN WELL BELOW NORMAL AS MODIFIED AIR POURS
IN TO THE AREA...BUT THIS TIME OF YEAR THAT MEANS TEMPS MAINLY IN
THE 50S. PLENTY OF SUNSHINE WILL ALLOW AFTERNOON MAX TEMPS TO REACH
TO 80 OR ABOVE...BUT DEWPOINTS WILL DROP INTO THE 40S AWAY FROM THE
COAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
WHILE WE HAVE MAINTAINED PREVAILING VFR THROUGH 00Z FRIDAY...THERE
IS THE RISK OF MVFR CONDITIONS IN LIGHT FOG/STRATUS A FEW HOURS
EITHER SIDE OF DAYBREAK...AND ALSO MARGINAL MVFR CONDITIONS IN
ISOLATED TO SCATTERED SHRA/TSRA WITH A PRE-FRONTAL TROUGH IN THE
LATE MORNING THROUGH MID AFTERNOON. IF THE TROUGH IS QUICKER THAN
ANTICIPATED THERE COULD BE SOME GUSTY WINDS LATE IN THE TAF CYCLE.
EXTENDED AVIATION...VFR. WINDS COULD GET A BIT GUSTY FRIDAY AFTERNOON
BEHIND THE SECONDARY FRONT.
&&
.MARINE...
TONIGHT...THE SUB TROPICAL RIDGE IN THE ATLANTIC CENTERED OUT NEAR
32N AND 60W WILL START TO RELAX ITS GRIP ACROSS THE COASTAL WATERS
LATE...AS IT STARTS TO GIVE WAY TO AN UPSTREAM PRE-FRONTAL TROUGH.
THE PRESSURE GRADIENT WILL TEMPORARILY TIGHTEN A BIT BETWEEN THESE
TWO FEATURES...ALLOWING FOR SE AND SOUTH WINDS UP TO 15 KT THROUGH
ABOUT 06-08Z...BEFORE DROPPING OFF TO 10 OR LESS LATE. SEAS WON/T
CHANGE MUCH...AVERAGING 2-4 FT AND HIGHEST ACROSS THE OUTER GA
WATERS. WE/LL NEED TO MONITOR FOR SOME GUSTY SHOWERS/T-STORMS
OVERNIGHT AS LOW LEVEL CONVERGENCE INCREASES.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 222323
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
723 PM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
LESS MOISTURE THIS AFTERNOON THAN YESTERDAY...AND RESULTING
INSTABILITY WEAKER. SHOWERS ALONG SEA BREEZE FRONT WEAKENING AS
THEY MOVE INTO MIDLANDS. STRONGER CONVECTION IN NORTH
GEORGIA/UPSTATE BUT LITTLE MOVEMENT INTO MIDLANDS. WILL CUT POPS
BACK FROM PREVIOUS FORECAST...SLIGHT CHANCE REST OF AFTERNOON AND EVENING.
SKIES WILL BECOME MOSTLY CLOUDY TONIGHT AS THE FRONT APPROACHES
FROM THE WEST WITH CHANCES OF SHOWERS INCREASING FROM WEST TO EAST
DURING THE PRE-DAWN HOURS. OVERNIGHT LOWS WILL GENERALLY BE IN THE
MID 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSING THE EASTERN CONUS DURING THE
SHORT TERM. THE AIR MASS WILL BE UNSTABLE WITH A PRE-FRONTAL TROUGH
OVER THE MIDLANDS. LOW LEVEL MOISTURE LINGERS WITH PRECIPITABLE
WATER RANGING FROM 1.00 T0 1.75 INCHES. THE THREAT OF CONVECTION
WILL CONTINUE WITH THE HIGHEST CHANCE ACROSS THE MIDLANDS. WILL
RANGE POPS FROM NEAR 30 PERCENT CSRA TO 60 PERCENT NORTHEAST ON
THURSDAY. ALTHOUGH THE GFS IS SLIGHTLY FASTER...MODELS INDICATE THE
COLD FRONT CROSSING THE AREA THURSDAY NIGHT WITH THE CHANCE OF
CONVECTION ENDING.
THE TEMPERATURE GUIDANCE WAS CLOSE WITH HIGHS IN THE MID/UPPER 80S
AND LOWS IN THE LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
THROUGH WEDNESDAY. GFS ENSEMBLE INCREASE POPS SLIGHTLY THROUGH THE
MIDDLE OF NEXT WEEK. WILL KEEP THE FORECAST DRY GIVEN INCREASING
H500 HEIGHTS AS THE UPPER RIDGE BUILDS.
EXPECT BELOW NORMAL TEMPERATURES DURING THE WEEKEND AND NEAR NORMAL
DURING THE REST OF THE MEDIUM RANGE PERIOD.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
RADAR INDICATES CONVECTIVE ACTIVITY AT A MINIMUM ACROSS OUR FA. MOST
ACTIVITY CURRENTLY CONFINED TO THE UPSTATE SC AND N/CENT GA. HIGH
RES MODELS INDICATE ACTIVITY DEVELOPING TO OUR WEST NEAR AN UPPER
IMPULSE AND SURFACE TROUGH...WEAKENING AS IT MOVES EAST AND
APPROACHES THE FA LATE TONIGHT. GUIDANCE INDICATING CIG RESTRICTIONS
LATE TONIGHT...IN A CONTINUED MOIST SOUTHERLY LOW LEVEL FLOW. FOR
NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL MONITOR LATEST
GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED. UPPER IMPULSE
AND SURFACE TROUGH WILL MOVE THROUGH THURSDAY...POSSIBLY LEADING
TO SCT SHRA/TSRA...BUT CHANCES TOO LOW...ALONG WITH SOME TIMING
QUESTIONS...TO INCLUDE MENTION IN THE TAF AT THIS TIME.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCAE 222126
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
LESS MOISTURE THIS AFTERNOON THAN YESTERDAY...AND RESULTING
INSTABILITY WEAKER. SHOWERS ALONG SEA BREEZE FRONT WEAKENING AS
THEY MOVE INTO MIDLANDS. STRONGER CONVECTION IN NORTH
GEORGIA/UPSTATE BUT LITTLE MOVEMENT INTO MIDLANDS. WILL CUT POPS
BACK FROM PREVIOUS FORECAST...SLIGHT CHANCE REST OF AFTERNOON AND EVENING.
SKIES WILL BECOME MOSTLY CLOUDY TONIGHT AS THE FRONT APPROACHES
FROM THE WEST WITH CHANCES OF SHOWERS INCREASING FROM WEST TO EAST
DURING THE PRE-DAWN HOURS. OVERNIGHT LOWS WILL GENERALLY BE IN THE
MID 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSING THE EASTERN CONUS DURING THE
SHORT TERM. THE AIR MASS WILL BE UNSTABLE WITH A PRE-FRONTAL TROUGH
OVER THE MIDLANDS. LOW LEVEL MOISTURE LINGERS WITH PRECIPITABLE
WATER RANGING FROM 1.00 T0 1.75 INCHES. THE THREAT OF CONVECTION
WILL CONTINUE WITH THE HIGHEST CHANCE ACROSS THE MIDLANDS. WILL
RANGE POPS FROM NEAR 30 PERCENT CSRA TO 60 PERCENT NORTHEAST ON
THURSDAY. ALTHOUGH THE GFS IS SLIGHTLY FASTER...MODELS INDICATE THE
COLD FRONT CROSSING THE AREA THURSDAY NIGHT WITH THE CHANCE OF
CONVECTION ENDING.
THE TEMPERATURE GUIDANCE WAS CLOSE WITH HIGHS IN THE MID/UPPER 80S
AND LOWS IN THE LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
THROUGH WEDNESDAY. GFS ENSEMBLE INCREASE POPS SLIGHTLY THROUGH THE
MIDDLE OF NEXT WEEK. WILL KEEP THE FORECAST DRY GIVEN INCREASING
H500 HEIGHTS AS THE UPPER RIDGE BUILDS.
EXPECT BELOW NORMAL TEMPERATURES DURING THE WEEKEND AND NEAR NORMAL
DURING THE REST OF THE MEDIUM RANGE PERIOD.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
CURRENT MESOANALYSIS INDICATES GENERALLY MODERATE INSTABILITY OVER
THE REGION. SCATTERED SHOWERS AND A FEW THUNDERSTORMS CURRENTLY
ALONG A SEA BREEZE...BUT COVERAGE HAS BEEN DECREASING IN THE LAST
HOUR OR SO. OTHER CONVECTIVE ACTIVITY OVER THE UPSTATE AND PORTIONS
OF N/NE GA...MOVING SLOWLY. WILL EXPECT ACTIVITY TO GRADUALLY
DISSIPATE AND NOT AFFECT TERMINALS. OBS INDICATE MAINLY SCT CU
WITH BASES ABOVE VFR. HIGH RES MODELS INDICATE MORE SIGNIFICANT
ACTIVITY DEVELOPING TO OUR WEST NEAR AN UPPER IMPULSE AND SURFACE
TROUGH...WEAKENING AS IT APPROACHES THE FA LATE TONIGHT. GUIDANCE
INDICATING CIG RESTRICTIONS LATE TONIGHT...IN A CONTINUED MOIST
SOUTHERLY LOW LEVEL FLOW. UPPER IMPULSE AND SURFACE TROUGH WILL
MOVE THROUGH THURSDAY...POSSIBLY LEADING TO SCT SHRA/TSRA...BUT
CHANCES TOO LOW...ALONG WITH SOME TIMING QUESTIONS...TO INCLUDE
MENTION IN THE TAF AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE FRIDAY.
OTHERWISE...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KFFC 221950
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
350 PM EDT WED MAY 22 2013
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AFTERNOON CONVECTION EXPECTED TO INCREASE IN COVERAGE AND PERSIST
INTO THE EVENING AND OVERNIGHT HOURS AS UPPER LEVEL TROUGH MOVES
THROUGH THE MISSISSIPPI VALLEY. CONVECTION EXPECTED TO BECOME MORE
ORGANIZED AS ASSOCIATED SHORT WAVE FOCUSES DEVELOPMENT. MODELS A
LITTLE INCONSISTENT WITH THE DEVELOPMENT AND/OR PROGRESSION OF THE
ORGANIZED PRECIPITATION...BUT WITH INCREASING
INSTABILITIES...DIURNAL HEATING...AND INCREASING SHEAR ACROSS THE
AREA...FEEL THERE IS ENOUGH TO SUPPORT GOOD CHANCE TO LIKELY
POPS...ESPECIALLY ACROSS NORTH GEORGIA. HAVE CONTINUED MENTION OF
POSSIBLE SEVERE STORMS...ACCOMPANIED WITH GUSTY WINDS AND SMALL
HAIL...IN THE GRIDS THROUGH 02Z TONIGHT ACROSS NORTH
GEORGIA...GENERALLY NORTH OF THE ATL METRO AREA. HAVE ALSO
QUICKLY TAPERED OFF EVENING AND OVERNIGHT POPS INTO THURSDAY
MORNING...WITH GENERALLY SLIGHT CHANCE POPS ACROSS THE AREA THROUGH
THE DAY THURSDAY AS SHORT WAVE PUSHES INTO THE CAROLINAS.
AS PREVIOUSLY MENTIONED...THE SEVERE THREAT IS PRIMARILY CONFINED TO
NORTH GEORGIA...THOUGH STRONG STORMS CAN BE EXPECTED ACROSS MUCH OF
THE CWA. THE PRIMARY CONCERNS IN SEVERE ACTIVITY WILL BE GUSTY WINDS
TO 60 MPH OR HIGHER...1 INCH HAIL OR HIGHER...FREQUENT LIGHTNING AND
PERIODS OF HEAVY RAINFALL. GUSTY WINDS AND SMALL HAIL ARE ALSO
POSSIBLE IN THE STRONGER STORMS.
PRESSURE GRADIENT TIGHTENS THURSDAY AFTERNOON AND INTO FRIDAY...WITH
WINDS 10 TO 15 MPH WITH GUSTS NEAR 20 MPH...ESPECIALLY ACROSS NORTHERN
AND EASTERN GEORGIA.
FOR THE TEMPERATURES..HAVE GENERALLY GONE WITH A GUIDANCE BLEND.
TEMPERATURES THURSDAY MORNING ARE EXPECTED TO BE IN THE 60S...AND
DEPENDING ON THE TIMING OF THE DIMINISHING CONVECTION AND CLOUDS OUT
OF THE AREA...THIS COULD IMPACT MORNING LOWS BY A FEW DEGREES.
TEMPERATURES WILL BE BACK IN THE LOW TO MID 80S THURSDAY AFTERNOON
BEFORE COOLING BY FRIDAY.
31
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED PORTION OF THE FORECAST. A MUCH
DRIER AIRMASS MOVES OVER THE AREA FRIDAY WITH DRY NW FLOW ALOFT
AND SURFACE HIGH PRESSURE BUILDING OVER THE OH/TN VALLEYS DURING
THE DAY. GRADIENT WINDS WILL INCREASE GETTING CLOSE TO WIND
ADVISORY CRITERIA(20 MPH SUSTAINED) FOR SOME AREAS. DRY CONDITIONS
SHOULD CONTINUE THROUGH THE WEEKEND EVEN WITH SLIGHT DIFFERENCES
BETWEEN THE GFS AND ECMWF. THE NW FLOW ALOFT N OF THE AREA IS
EXPECTED TO BECOME MORE ACTIVE WITH INCREASED PRECIP CHANCES NORTH
OF THE STATE...BUT IT SHOULD STAY DRY ACROSS GA. LOOKS LIKE THE
BETTER MOISTURE FINALLY MOVES IN ACROSS THE AREA BY THE BEGINNING
OF NEXT WEEK SO WILL SLOWLY INCREASE CHANCES OF POPS MON THROUGH DAY
7. TEMPERATURES GENERALLY RUNNING WITHIN 5 DEGREES OF NORMAL
THROUGH THE PERIOD EXCEPT SATURDAY ND SUNDAY MORNING LOWS ARE
RUNNING 10-15 DEGREES BELOW NORMAL.
01
&&
.AVIATION...
18Z UPDATE...
CONVECTION WILL CONTINUE TO INCREASE IN COVERAGE ACROSS THE STATE
THIS AFTERNOON AND EVENING. HAVE GENERALLY TEMPO TS FOR THE ATL
AREA AND AHN TAF SITES TO ACCOUNT FOR TS IN THE AREA THIS
AFTERNOON...AND PREVAILING TS AS MORE ORGANIZED CONVECTION MOVES
IN 00-02Z. CSG AND MCN AREAS LOOK TO BE PRIMARILY IMPACTED THIS
EVENING WITH THE MAIN CONVECTION LINE. OVERALL...ANTICIPATING VFR
CONDITIONS...WITH SOME RESTRICTED VSBYS IN THE TS. AHN COULD SEE
SCT-BKN IFR 08-13Z WITH LINGERING MOISTURE IN THE AREA. WINDS WILL
BE GENERALLY SOUTHWESTERLY THIS AFTERNOON...SWITCHING TO THE WEST
OR NORTHWEST WITH THE FRONTAL PASSAGE TONIGHT. VRB GUSTY WINDS
EXPECTED IN CONVECTION TODAY. GUSTY NW WINDS EXPECTED BY THURSDAY
AFTERNOON...GENERALLY G18-24KT.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON CONVECTION TIMING.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 85 59 79 / 60 20 5 0
ATLANTA 66 83 59 76 / 60 10 5 0
BLAIRSVILLE 61 78 54 71 / 60 20 10 0
CARTERSVILLE 63 83 57 76 / 60 10 5 0
COLUMBUS 68 89 63 82 / 60 10 5 0
GAINESVILLE 64 82 57 75 / 60 10 5 0
MACON 65 89 60 83 / 60 20 5 0
ROME 63 84 57 77 / 50 10 5 0
PEACHTREE CITY 63 85 58 77 / 60 10 5 0
VIDALIA 68 89 65 88 / 40 20 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....01
AVIATION...31
000
FXUS62 KCHS 221927
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
327 PM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONGOING SCATTERED CONVECTION ALONG THE SEABREEZE WILL GRADUALLY
SHIFT INLAND THROUGH THE REMAINDER OF THE AFTERNOON HOURS...THEN
STEADILY DIMINISH IN COVERAGE AS THE MARGINAL INSTABILITY THIS
AFTERNOON FURTHER DECREASES WITH SUNSET. HAVE THUS INDICATED 20 TO
30 PERCENT RAIN CHANCES DECREASING FROM EAST TO WEST TOWARD THE
EVENING HOURS. LATEST MESOANALYSIS REVEALS RATHER UNIMPRESSIVE
INSTABILITY THIS AFTERNOON...AND WHEN CONSIDERING WEAK LAPSE
RATES AND VERTICAL WIND PROFILES...SEVERE THUNDERSTORM POTENTIAL
IS LOW THROUGH THIS EVENING.
THE SOUTHEAST STATES WILL BECOME LOCATED ALONG THE PERIPHERY OF A
BROAD UPPER TROUGH STRETCHING FROM THE GREAT LAKES REGION INTO THE
LOWER MISSISSIPPI VALLEY TONIGHT. SOUTH/SOUTHEAST FLOW AROUND
PERSISTENT ATLANTIC SURFACE HIGH PRESSURE WILL CONTINUE TO
SUPPORT DECENT LOW LEVEL MOISTURE OVERNIGHT. BEST INSTABILITY AND
CONVERGENCE WILL SHIFT INTO THE COASTAL WATERS AFTER
MIDNIGHT...AND NUMERICAL MODEL SOLUTIONS SUGGEST ISOLATED SHOWERS
COULD DEVELOP IN THE MARINE ZONES DURING THE EARLY MORNING HOURS.
CONSIDERING AN ONSHORE COMPONENT TO THE SURFACE FLOW...THERE
REMAINS A SLIGHT CHANCE THAT SHOWERS COULD SHIFT LOCALLY ONSHORE
MAINLY ALONG THE CHARLESTON COUNTY COASTLINE. A COLD FRONT WILL
ALSO BE APPROACHING FROM THE WEST...AND A PRE FRONTAL TROUGH
FEATURE WILL ENHANCE MOISTURE/CONVERGENCE DOWNSTREAM...PERHAPS
SUPPORTING THE INTRUSION OF SHOWERS INTO FAR INLAND ZONES JUST
BEFORE SUNRISE. HAVE THUS PINNED THE FORECAST AREA BETWEEN SLIGHT
CHANCE POPS TO THE WEST AND SLIGHT CHANCES ALONG THE NORTHERN
COAST BY DAYBREAK. OVERALL HOWEVER...THE MAJORITY OF THE AREA WILL
REMAIN DRY OVERNIGHT. TEMPERATURES WILL FALL INTO THE MID TO UPPER
60S.
ALTHOUGH PATCHY FOG DEVELOPMENT IS POSSIBLE AFTER MIDNIGHT...MODEL
GUIDANCE REMAINS RATHER CONSERVATIVE IN DEPICTING ANY REDUCED
VISIBILITIES. CONSIDERING SOME UNCERTAINTY IN THE POTENTIAL FOR
CLOUD COVER TO RETURN OVERNIGHT...AS WELL AS LESS RAIN COVERAGE
TODAY...PREFER TO KEEP FOG OUT OF THE FORECAST AT THIS TIME.
SUBSEQUENT FORECAST SHIFTS WILL BE ABLE TO REASSESS TRENDS WITH
THE EVENING UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A SURFACE PRESSURE TROF WILL MOVE INTO THE CWA ON THURSDAY...WITH
MOIST SOUTHERLY WINDS AHEAD OF IT AND SOMEWHAT DRIER WESTERLY WINDS
BEHIND IT. THE TROF SHOULD BE ROUGHLY ALONG INTERSTATE 95 BY EARLY
AFTERNOON...AND AREAS ALONG AND EAST OF THE BOUNDARY WILL HAVE A
CHANCE OF SHOWERS AND THUNDERSTORMS AS DAYTIME HEATING CREATES SOME
SURFACE INSTABILITY AND CONVERGENCE. FURTHER WEST...ESPECIALLY OVER
OUR INTERIOR GEORGIA COUNTIES...THE ATMOSPHERE WILL BE DRIER AND
MORE STABLE...SO THERE WILL ONLY BE A SLIGHT CHANCE OF SHOWERS.
SKIES SHOULD AVERAGE OUT PARTLY CLOUDY...ALTHOUGH THERE WILL BE A
PERIOD OF MOSTLY CLOUDY SKIES TO THE EAST OF THE BOUNDARY DURING A
PORTION OF THE AFTERNOON.
THURSDAY NIGHT...THE INITIAL COOL FRONT PUSHES THROUGH THE
AREA...MOVING THE CHANCES FOR RAIN MOSTLY OFFSHORE...ALTHOUGH I
CANNOT RULE OUT A SLIGHT CHANCE OVER THE TRI COUNTY AREA AS THERE
MAY BE ENOUGH REMNANT MOISTURE WITH THE FRONT TO PROMOTE SOME
SHOWERS.
FRIDAY...THE WINDS WILL BE NORTHWEST BEHIND THE FRONT IN THE
MORNING...PROMOTING SOME DOWNSLOPE LOW LEVEL FLOW AND HEATING.
HOWEVER...DRIER AIR MOVING IN SHOULD PREVENT ANY RAIN...OR MUCH IN
THE WAY OF CLOUDS FOR THAT MATTER. A SECONDARY COLD FRONT WILL MOVE
THROUGH LATER IN THE DAY...CAUSING THE WINDS TO VEER TO NORTH AND
INCREASE AS COLD ADVECTION PICKS UP. FRIDAY NIGHT WILL BE MUCH
COOLER THAN THE PREVIOUS FEW.
SATURDAY...TEMPS WILL BEGIN WELL BELOW NORMAL AS MODIFIED AIR POURS
IN TO THE AREA...BUT THIS TIME OF YEAR THAT MEANS TEMPS MAINLY IN
THE 50S. PLENTY OF SUNSHINE WILL ALLOW AFTERNOON MAX TEMPS TO REACH
TO 80 OR ABOVE...BUT DEWPOINTS WILL DROP INTO THE 40S AWAY FROM THE
COAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR IS EXPECTED TO PREVAIL THROUGH THE AFTERNOON. SOME ISOLATED
SHOWERS COULD IMPACT MAINLY KSAV DURING THE FIRST FEW HOURS OF
THE VALID TAF PERIOD...WITH BRIEF PERIODS OF REDUCED VSBYS/CIGS
WITHIN HEAVIER RAINFALL. ACTIVITY WILL DIMINISH AFTER SUNSET. LATE
TONIGHT...RESTRICTIONS WILL BE POSSIBLE ONCE AGAIN DUE TO FOG
AND/OR STRATUS GIVEN SMALL SURFACE T/TD SPREADS...LIGHT
WINDS...AND MODEL SOUNDINGS INDICATING DECENT LOW LEVEL MOISTURE.
DUE TO LOW CONFIDENCE HAVE DECIDED TO KEEP VFR FOR NOW...BUT
SHOWED THE GENERAL DOWNWARD TREND IN THE TAF. AFTER SUNRISE...VFR
SHOULD RETURN. SHOWERS/THUNDERSTORMS WILL BE POSSIBLE IN THE
MORNING.
EXTENDED AVIATION...THERE COULD BE A BRIEF PERIOD OF MVFR/IFR IN
CONVECTION THURSDAY AFTERNOON...BUT VFR CONDITIONS ARE EXPECTED
OTHERWISE...CONTINUING INTO THE WEEKEND. THE WINDS COULD GET A BIT
GUSTY FRIDAY AFTERNOON BEHIND THE SECONDARY FRONT.
&&
.MARINE...
MARINE CONDITIONS WILL BE FAIRLY BENIGN THROUGH TONIGHT...AS THE
AREA REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE.
EXPECT A GENERAL SOUTHERLY FLOW TO PREVAIL...WITH WIND SPEEDS
BELOW 15 KT.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WMS
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...ECT
MARINE...FWA/WMS
TIDES/COASTAL FLOODING...
000
FXUS62 KFFC 221837
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
237 PM EDT WED MAY 22 2013
.PREV DISCUSSION... /ISSUED 745 AM EDT WED MAY 22 2013/
SHORT TERM /TODAY THROUGH THURSDAY/...
UPPER TROUGH WILL MOVE THROUGH THE UPPER MISSISSIPPI VALLEY TODAY
INTO TONIGHT. AN ASSOCIATED SHORT WAVE TRAILING INTO THE SOUTHERN
STATES WILL HELP FOCUS SHOWERS AND THUNDERSTORMS ACROSS THE CWA
THROUGH TONIGHT. AREA OF THUNDERSTORMS CURRENTLY MOVING INTO ALABAMA
MAY REACH NORTHWEST GEORGIA BY SUNRISE IF THEY HOLD TOGETHER. THIS
COMBINED WITH VARIOUS OUTFLOW BOUNDARIES WILL MAKE TIMING OF
CONVECTION DIFFICULT. HOWEVER THE BEST CHANCES WOULD SEEM TO BE THIS
AFTERNOON AND EVENING WITH DIURNAL HEATING. HAVE CONTINUED WITH THE
SEVERE WORDING ACROSS PORTIONS OF NORTH THIS AFTERNOON. THIS FITS
WELL WITH THE SPC SLIGHT RISK AREA. DIMINISHING POPS OVERNIGHT AS
THE SHORT WAVE MOVES INTO THE CAROLINAS. SOME DRYING INDICATED FOR
THURSDAY BUT WITH APPROACHING UPPER TROUGH...HAVE LEFT LOW POPS IN
ACROSS THE CWA. BASED ON TUESDAYS TEMPERATURES...HAVE STAYED ON THE
WARM SIDE OF MAV/MET. HOWEVER WITH ADDITIONAL CLOUDS AND
PRECIPITATION EXPECTED FOR TODAY...TEMPERATURES MAY VARY MORE ACROSS
THE CWA.
41
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A WEAK COLD FRONT AND MAIN UPPER SUPPORT WILL BE EXITING THE AREA
THURSDAY NIGHT. IT IS UNCLEAR HOW MUCH CONVECTIVE ACTIVITY THERE
WILL BE WITH THE GFS AND NAM INDICATING LITTLE OR NO MEASURABLE
RAIN AMOUNTS. LOOKS LIKE NO MORE THAN A SLIGHT CHANCE OF SHOWERS OR
THUNDERSTORMS FOR THE FIRST PART OF THURSDAY NIGHT.
MUCH DRIER AIRMASS MOVES OVER THE AREA ON FRIDAY WITH DRY NW FLOW
ALOFT AND SURFACE HIGH PRESSURE BUILDING OVER THE OH/TN VALLEYS
DURING THE DAY. GRADIENT WINDS WILL INCREASE GETTING CLOSE TO WIND
ADVISORY CRITERIA(20 MPH SUSTAINED) FOR SOME AREAS. DRY CONDITIONS
CONTINUE SATURDAY AND MOSTLY SUNDAY. HOWEVER THE NW FLOW ALOFT N OF
THE AREA IS BECOMING MORE ACTIVE WITH PRECIP CHANCES AND WHILE THE
GFS IS DRY FOR OUR AREA ON SUNDAY...MOISTURE IS SKIRTING NE GA. THE
EUROPEAN MEANWHILE IS INDICATING LIGHT PRECIP AMOUNTS OVER FAR N AND
E GA ON SUNDAY. A SIMILAR PATTERN CONTINUES FOR MONDAY AND TUESDAY
AS WELL. HIGH PRESSURE ALOFT BUILDS FOR WEDNESDAY AND EVEN WILL
SOUTHERLY FLOW OVER THE AREA...HIGH PRESSURE ALOFT WILL KEEP ANY
PRECIP CHANCES TO A MINIMUM. FOR NOW WILL FAVOR THE DRIER GFS.
TEMPERATURES GENERALLY RUNNING WITHIN 5 DEGREES OF NORMAL THROUGH
THE PERIOD EXCEPT SATURDAY MORNING LOWS ARE RUNNING 10-15 DEGREES
BELOW NORMAL AND SUNDAY MORNING LOWS ARE RUNNING CLOSE TO 10
DEGREES BELOW NORMAL.
BDL
&&
.AVIATION...
18Z UPDATE...
CONVECTION WILL CONTINUE TO INCREASE IN COVERAGE ACROSS THE STATE
THIS AFTERNOON AND EVENING. HAVE GENERALLY TEMPO TS FOR THE ATL
AREA AND AHN TAF SITES TO ACCOUNT FOR TS IN THE AREA THIS
AFTERNOON...AND PREVAILING TS AS MORE ORGANIZED CONVECTION MOVES
IN 00-02Z. CSG AND MCN AREAS LOOK TO BE PRIMARILY IMPACTED THIS
EVENING WITH THE MAIN CONVECTION LINE. OVERALL...ANTICIPATING VFR
CONDITIONS...WITH SOME RESTRICTED VSBYS IN THE TS. AHN COULD SEE
SCT-BKN IFR 08-13Z WITH LINGERING MOISTURE IN THE AREA. WINDS WILL
BE GENERALLY SOUTHWESTERLY THIS AFTERNOON...SWITCHING TO THE WEST
OR NORTHWEST WITH THE FRONTAL PASSAGE TONIGHT. VRB GUSTY WINDS
EXPECTED IN CONVECTION TODAY. GUSTY NW WINDS EXPECTED BY THURSDAY
AFTERNOON...GENERALLY G18-24KT.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON CONVECTION TIMING.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 65 85 59 / 40 60 20 5
ATLANTA 86 66 83 59 / 50 60 10 5
BLAIRSVILLE 80 61 78 54 / 60 60 20 10
CARTERSVILLE 84 63 83 57 / 60 60 10 5
COLUMBUS 90 68 89 63 / 40 60 10 5
GAINESVILLE 85 64 82 57 / 70 60 10 5
MACON 90 65 89 60 / 50 60 20 5
ROME 84 63 84 57 / 70 50 10 5
PEACHTREE CITY 86 63 85 58 / 50 60 10 5
VIDALIA 88 68 89 65 / 30 40 20 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...31
LONG TERM....01
AVIATION...31
000
FXUS62 KCAE 221829
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
229 PM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE OFF THE ATLANTIC COAST CONTINUES TO PUSH MOISTURE
INTO THE FORECAST AREA WITH SATELLITE IMAGERY SHOWING CUMULUS
DEVELOPING ACROSS THE REGION. CAE WSR-88D RETURNS SHOWS SHOWERS
DEVELOPING THROUGH THE CSRA AS WELL AS ACTIVITY ALONG THE
INTENSIFYING SEA BREEZE. EXPECT THE SHOWERS TO INCREASE IN
COVERAGE OVER THE NEXT COUPLE OF HOURS...WITH SOME BECOMING
THUNDERSTORMS. SEVERE THREAT REMAINS LOW WITH ISOLATED HAIL AND
GUSTY WINDS THE MAIN CONCERNS. CONVECTION WILL DIMINISH WITH LOSS
OF HEATING THIS EVENING AND CEASE OVERNIGHT. SKIES WILL REMAIN
MOSTLY CLOUDY THROUGH THE NIGHT AS THE FRONT APPROACHES FROM THE
WEST WITH CHANCES OF SHOWERS INCREASING FROM WEST TO EAST DURING
THE PRE-DAWN HOURS. OVERNIGHT LOWS WILL GENERALLY BE IN THE MID
60S.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSING THE EASTERN CONUS DURING THE
SHORT TERM. THE AIRMASS WILL BE UNSTABLE WITH A PRE-FRONTAL TROUGH
OVER THE MIDLANDS. LOW LEVEL MOISTURE LINGERS WITH PRECIPITABLE
WATER RANGING FROM 1.00 T0 1.75 INCHES. THE THREAT OF CONVECTION
WILL CONTINUE WITH THE HIGHEST CHANCE ACROSS THE MIDLANDS. WILL
RANGE POPS FROM NEAR 30 PERCENT CSRA TO 60 PERCENT NORTHEAST ON
THURSDAY. ALTHOUGH THE GFS IS SLIGHTLY FASTER...MODELS INDICATE THE
COLD FRONT CROSSING THE AREA THURSDAY NIGHT WITH THE CHANCE OF
CONVECTION ENDING.
THE TEMPERATURE GUIDANCE WAS CLOSE WITH HIGHS IN THE MID/UPPER 80S
AND LOWS IN THE LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
THROUGH WEDNESDAY. GFS ENSEMBLE INCREASE POPS SLIGHTLY THROUGH THE
MIDDLE OF NEXT WEEK. WILL KEEP THE FORECAST DRY GIVEN INCREASING
H500 HEIGHTS AS THE UPPER RIDGE BUILDS.
EXPECT BELOW NORMAL TEMPERATURES DURING THE WEEKEND AND NEAR NORMAL
DURING THE REST OF THE MEDIUM RANGE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD.
SATELLITE IMAGERY SHOWS THE STRATUS ASSOCIATED WITH MORNING FOG
HAS BURNED OFF WITH CUMULUS DEVELOPING AS TEMPERATURES RISING INTO
THE LOWER 80S. WSR-88D IMAGERY SHOWS SHOWERS TO THE SOUTHWEST OF
AGS/DNL WITH ADDITIONAL SHOWERS ALONG THE DEVELOPING SEA BREEZE
TOWARD THE COAST. EXPECT THE SHOWERS TO INCREASE IN COVERAGE OVER
THE NEXT COUPLE OF HOURS WITH SOME INTENSIFYING INTO
THUNDERSTORMS. AS SUCH HAVE INCLUDED A TEMPO FOR SHOWERS IN THE
AGS/DNL AREA WHILE CONFIDENCE IN OTHER LOCATIONS REMAINS TOO LOW
ATTM. OVERNIGHT FOG DEVELOPMENT THREAT ALSO REMAINS LOW AS THE
COLD FRONT APPROACHES FROM THE WEST PREVENTING A STRONG INVERSION
FROM DEVELOPING. FRONT WILL CROSS THE AREA THURSDAY MORNING AND
WITH THE FRONT WEAKENING AS IT MOVES INTO THE AREA CONFIDENCE IN
RAIN WITH THE FRONT IS LOW.
EXTENDED AVIATION OUTLOOK...
INCREASING CONFIDENCE IN STRONG AND GUSTY WINDS FRIDAY LATE
MORNING INTO FRIDAY EVENING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 221741
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
141 PM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE WEAK UPPER LEVEL PATTERN WILL GRADUALLY TRANSITION TODAY...AS
THE BAGGY TROUGH OVER THE SOUTHEAST STATES BECOMES MORE ABSORBED
INTO THE PERIPHERY OF A STRONGER TROUGH CURRENTLY OVER THE
MISSISSIPPI VALLEY. DEEP MOISTURE STILL LINGERS OVER THE
AREA...SEEN IN VERTICAL SOUNDINGS WITH PRECIPITABLE WATER VALUES
AROUND 1.5 INCHES. WITH THE FORECAST AREA STILL UNDER THE
INFLUENCE OF ATLANTIC SURFACE HIGH PRESSURE...SOUTH/SOUTHEAST
FLOW WILL PREVAIL AND HAS ALLOWED THE SEABREEZE TO DEVELOP EARLY.
SEABREEZE FORCING WITHIN ABUNDANT MOISTURE HAS SUPPORTED THE
INITIATION OF ISOLATED TO SCATTERED SHOWERS.
LACKING ANY OTHER NOTABLE FORCING MECHANISMS...CONVECTIVE
DEVELOPMENT AND EVOLUTION TODAY IS MAINLY DRIVEN BY THE SEABREEZE
PROGRESSION AND TYPICAL DIURNAL HEATING AND INSTABILITY. THE
PRECIPITATION FORECAST WILL THUS INDICATE SHOWERS CURRENTLY ALONG
THE SEABREEZE SPREADING INLAND AS THE AFTERNOON PROGRESSES. HAVE
MAINTAINED RAIN CHANCES IN THE 20 TO 30 PERCENT RANGE. LATEST
MESOANALYSIS REVEALS RATHER UNIMPRESSIVE INSTABILITY BY EARLY
AFTERNOON...AND WHEN CONSIDERING WEAK LAPSE RATES AND VERTICAL
WIND PROFILES...SEVERE THUNDERSTORM POTENTIAL APPEARS LOW. IN
FACT...ONGOING CONVECTION HAS STRUGGLED TO PRODUCE LIGHTNING BY 1
PM EDT. HOWEVER...AS COMMON THIS TIME OF YEAR...AN ISOLATED STRONG
TO SEVERE THUNDERSTORM CANNOT BE RULED OUT WHERE BOUNDARY
INTERACTIONS OCCUR. OTHERWISE...THE MAIN HAZARD ASSOCIATED WITH
SHOWERS/THUNDERSTORMS WILL BE HEAVY DOWNPOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
DIURNAL CONVECTION WILL TAPER OFF EARLY THIS EVENING OVER
LAND...WHILE ISOLATED SHOWERS OR STORMS WILL REMAIN POSSIBLE OVER
THE COASTAL WATERS TONIGHT. SOME FOG IS POSSIBLE LATE
TONIGHT/EARLY THURSDAY MORNING...ESPECIALLY IN AREAS WHERE RAIN
OCCURS TODAY.
THURSDAY...ATLANTIC HIGH PRESSURE WILL PREVAIL WHILE WEAK TROUGHING
PERSISTS INLAND. A SHORTWAVE EMBEDDED WITHIN BROAD UPPER LEVEL
TROUGHING WILL CROSS THE REGION AND PUSH THE DEEP LAYERED MOISTURE
OFFSHORE AS THE DAY PROGRESSES. THERE IS THE POTENTIAL FOR ISOLATED
CONVECTION ACROSS THE AREA IN THE MORNING AHEAD OF THE SHORT
WAVE...WITH THE COVERAGE INCREASING TO SCATTERED IN THE AFTERNOON
ACROSS MUCH OF SOUTHEAST SOUTH CAROLINA WHERE PRECIPITABLE WATER
VALUES AND LOW LEVEL CONVERGENCE WILL BE MAXIMIZED. A
WESTERLY/DOWNSLOPE FLOW ALOFT WILL PUSH TEMPERATURES TO HIGHS IN THE
UPPER 80S TO AROUND 90 AWAY FROM THE IMMEDIATE COAST.
THURSDAY NIGHT...AN UPPER LEVEL TROUGH WILL DIG TOWARD THE
APPALACHIANS...PUSHING A COLD FRONT ACROSS THE AREA. OTHER THAN SOME
ISOLATED CONVECTION EARLY IN THE EVENING MAINLY ACROSS THE
CHARLESTON TRI-COUNTY AREA...THE FRONT SHOULD PASS THROUGH RELATIVE
RAIN-FREE DUE TO A LACK OF DEEP LAYERED MOISTURE. LOWS WILL BE IN
THE LOWER TO MID 60S.
FRIDAY...THE UPPER LEVEL TROUGH WILL MOVE OVER THE MID-ATLANTIC AS
SURFACE HIGH PRESSURE BEGINS TO BUILD IN FROM THE GREAT LAKES REGION
IN WAKE OF THE DEPARTING COLD FRONT. MUCH DRIER AIR WILL FILTER INTO
THE AREA WITH A STRONG NORTHWEST/DOWNSLOPE WIND COMPONENT. THERE
WILL BE CONSIDERABLE SUNSHINE ALONG WITH BREEZY CONDITIONS IN THE
AFTERNOON. THE DOWNSLOPE FLOW WILL NEGATE MUCH OF THE COLD AIR
ADVECTION...ALLOWING TEMPERATURES TO REACH HIGHS IN THE MID AND
UPPER 80S ACROSS THE AREA AWAY FROM THE IMMEDIATE COAST.
FRIDAY NIGHT...RADIATIONAL COOLING WILL BE LIMITED BY A COUPLED
NORTHERLY FLOW THROUGH MUCH OF THE NIGHT...BUT THE DRY AIR MASS AND
CLEAR SKIES SHOULD STILL ALLOW TEMPERATURES TO FALL INTO THE THE MID
AND UPPER 50S...WITH SOME LOWER 50S POSSIBLE WELL INLAND.
SATURDAY...AN EXTREMELY DRY AIR MASS WILL BE IN PLACE TO START THE
WEEKEND...WITH PRECIPITABLE WATER VALUES AS LOW AS .25 TO .50 INCHES
WHICH IS MORE THAN 2 STANDARD DEVIATIONS BELOW NORMAL FOR THIS TIME
OF YEAR. GIVEN THIS DRY AIR MASS...THERE WILL BE CONSIDERABLE
SUNSHINE BUT A NORTH-NORTHEAST FLOW WILL LIMIT HIGHS TO THE UPPER
70S TO LOWER 80S ACROSS SOUTHEAST SOUTH CAROLINA AND THE LOWER TO
MID 80S ACROSS SOUTHEAST GEORGIA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR IS EXPECTED TO PREVAIL THROUGH THE AFTERNOON. SOME ISOLATED
SHOWERS COULD IMPACT MAINLY KSAV DURING THE FIRST FEW HOURS OF
THE VALID TAF PERIOD...WITH BRIEF PERIODS OF REDUCED VSBYS/CIGS
WITHIN HEAVIER RAINFALL. ACTIVITY WILL DIMINISH AFTER SUNSET. LATE
TONIGHT...RESTRICTIONS WILL BE POSSIBLE ONCE AGAIN DUE TO FOG
AND/OR STRATUS GIVEN SMALL SURFACE T/TD SPREADS...LIGHT
WINDS...AND MODEL SOUNDINGS INDICATING DECENT LOW LEVEL MOISTURE.
DUE TO LOW CONFIDENCE HAVE DECIDED TO KEEP VFR FOR NOW...BUT
SHOWED THE GENERAL DOWNWARD TREND IN THE TAF. AFTER SUNRISE...VFR
SHOULD RETURN. SHOWERS/THUNDERSTORMS WILL BE POSSIBLE IN THE
MORNING.
EXTENDED AVIATION...ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH
THURSDAY. A COLD FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT
WITH HIGH PRESSURE THEN BUILDING OVER THE REGION THROUGH EARLY
NEXT WEEK.
&&
.MARINE...
MARINE CONDITIONS WILL BE FAIRLY BENIGN THROUGH TONIGHT...AS THE
AREA REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE.
THE SEABREEZE WILL DEVELOP BY LATE MORNING...HOWEVER WIND SPEEDS
AT THE COAST ARE STILL EXPECTED TO GENERALLY REMAIN BELOW 15 KT.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WMS
SHORT TERM...JAQ
LONG TERM...JAQ
AVIATION...ECT
MARINE...JAQ/JRL
TIDES/COASTAL FLOODING...
000
FXUS62 KCAE 221512
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1112 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...SATELLITE IMAGERY AND SURFACE OBS SHOW FOG CONTINUES TO
LIFT ACROSS THE AREA WITH LOW CLOUDS CONTINUING TO LINGER ACROSS
MUCH OF THE AREA. EXPECT THE CLOUDS TO BREAK UP A BIT PRODUCING
PARTLY SUNNY SKIES DURING THE LATE MORNING TO EARLY AFTERNOON
HOURS. WITH HIGH PRESSURE OFFSHORE AND SOUTHERLY WINDS PERSISTING
OVER THE AREA THERE WILL BE ANOTHER CHANCE OF AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS. THE MAIN THREAT WILL AGAIN BE
HEAVY RAIN AS PWAT VALUES REMAIN 1.6 INCHES OR GREATER. SEVERE
THUNDERSTORM POTENTIAL REMAINS LOW...HOWEVER AN ISOLATED SEVERE
CELL IS POSSIBLE WITH GUSTY WINDS AND LARGE HAIL. WITH THE CLOUD
COVER ACROSS THE FORECAST AREA THIS MORNING HAVE LOWERED HIGH
TEMPERATURES A DEGREE OR TWO WITH AFTERNOON HIGH TEMPERATURES IN
THE MIDDLE 80S.
PREVIOUS DISCUSSION...HIGH PRESSURE OFF THE SOUTHEAST COAST WILL
CONTINUE TO CIRCULATE MOIST AIR INTO THE FORECAST AREA TODAY. THE
NAM AND GFS CONTINUE TO INDICATE A WEAK MID-LEVEL SHORTWAVE TROUGH
LINGERING OVER THE FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS
MAINLY DURING THE TIME OF MAXIMUM HEATING. USED AN AVERAGE OF THE
GFS AND NAM MOS POPS. PRECIPITABLE WATER NEAR 1.7 OF AN INCH AND
SLOW STORM MOVEMENT SUPPORTS HEAVY RAIN WILL SOME OF THE
THUNDERSTORMS. HEAVY PRECIPITATION LOADINGS AND POSSIBLY MODERATE
INSTABILITY WITH H5 TEMPERATURES AROUND -10 SUPPORT A POSSIBILITY
OF DAMAGING WIND. USED THE WARMER TEMPERATURE GUIDANCE FOR TODAY
BASED ON YESTERDAY/S VERIFICATION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A CONTINUED MOIST SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH
PLUS A PRE-FRONTAL TROUGH SUPPORT THUNDERSTORMS TONIGHT. COVERAGE
WILL LIKELY BE LIMITED BY DIURNAL COOLING AND PREVIOUS CONVECTION.
THE NAM AND GFS MOS ARE IN GOOD AGREEMENT WITH POPS 30 TO 40 PERCENT.
THE MODELS SHOW THE PRE-FRONTAL TROUGH LINGERING THURSDAY BUT
DEEPER MOISTURE APPEARS TO SHIFT EAST OF THE FORECAST AREA EARLY
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE NAM AND GFS MOS
INDICATE VERY LOW POPS...BUT MAINTAINED CHANCE POPS BECAUSE OF
CONVERGENCE ASSOCIATED WITH THE PRE-FRONTAL TROUGH THURSDAY AND
THE COLD FRONT THURSDAY EVENING. FURTHER DRYING SHOULD OCCUR
BEHIND THE FRONT BY LATE THURSDAY NIGHT. THE TEMPERATURE GUIDANCE
WAS CLOSE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
AND TUESDAY. THE GFS AND ECMWF MOS PLUS GFS ENSEMBLE MEAN SUPPORTS
VERY LOW POPS. EXPECT BELOW NORMAL TEMPERATURES DURING THE
WEEKEND AND NEAR NORMAL DURING THE REST OF THE MEDIUM RANGE
PERIOD.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
MAINLY VFR CONDITIONS THROUGH THE TAF PERIOD.
FOG HAS ERODED ACROSS THE AREA WITH SOME LOW CLOUDS
REMAINING...WHICH WILL DISSIPATE OVER THE NEXT HOUR OR SO. MAIN
CONCERN THROUGH THE PERIOD WILL BE AFTERNOON AND EVENING
CONVECTION. EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
TO DEVELOP THIS AFTERNOON AND LINGER INTO THIS EVENING. CONFIDENCE
IN COVERAGE AND TIMING REMAIN TOO LOW TO INCLUDE IN TAFS ATTM.
POTENTIAL FOR FOG OVERNIGHT REMAINS LOW AS FRONT APPROACHES FROM
THE WEST...HOWEVER WITH A 25 KNOT LOW LEVEL JET ACROSS THE AREA
LOW STRATUS WILL BE POSSIBLE. MUCH OF THE STRATUS POTENTIAL WILL
DEPEND ON AFTERNOON SHOWERS SO HAVE KEPT STRATUS OUT OF TAFS ATTM.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH
THURSDAY NIGHT. LATE NIGHT/EARLY MORNING FOG/STRATUS ALSO
POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 221445
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1045 AM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE WEAK UPPER LEVEL PATTERN WILL GRADUALLY TRANSITION TODAY...AS
THE BAGGY TROUGH OVER THE SOUTHEAST STATES BECOMES MORE ABSORBED
INTO THE PERIPHERY OF A STRONGER TROUGH CURRENTLY OVER THE
MISSISSIPPI VALLEY. DEEP MOISTURE STILL LINGERS OVER THE
AREA...SEEN IN VERTICAL SOUNDINGS WITH PRECIPITABLE WATER VALUES
AROUND 1.5 INCHES. WITH THE FORECAST AREA STILL UNDER THE
INFLUENCE OF ATLANTIC SURFACE HIGH PRESSURE...SOLID SOUTHERLY FLOW
WILL PREVAIL AND HAS ALLOWED THE SEABREEZE TO DEVELOP EARLY.
SEABREEZE FORCING BY LATE MORNING WITHIN ABUNDANT MOISTURE HAS
ALREADY SUPPORTED THE INITIATION OF ISOLATED SHOWERS ACROSS
COASTAL COUNTIES BY 10 AM EDT.
LACKING ANY OTHER NOTABLE FORCING MECHANISMS...CONVECTIVE
DEVELOPMENT AND EVOLUTION TODAY IS EXPECTED TO BE MAINLY DRIVEN
BY THE SEABREEZE PROGRESSION AND TYPICAL DIURNAL HEATING AND
INSTABILITY. THE PRECIPITATION FORECAST WILL THUS INDICATE
THUNDERSTORMS DEVELOPING ALONG AND INLAND OF THE SEABREEZE BY LATE
MORNING...THEN SPREADING INLAND INTO THE AFTERNOON HOURS. HAVE
MAINTAINED RAIN CHANCES IN THE 20 TO 30 PERCENT RANGE. MODIFYING
THE MORNING SOUNDING AT KCHS FOR HIGH TEMPERATURES IN THE MID TO
UPPER 80S STILL INDICATES RATHER UNIMPRESSIVE INSTABILITY BY THIS
AFTERNOON...AND WHEN CONSIDERING WEAK LAPSE RATES AND VERTICAL
WIND PROFILES...SEVERE THUNDERSTORM POTENTIAL APPEARS LOW.
HOWEVER...AS COMMON THIS TIME OF YEAR...AN ISOLATED STRONG TO
SEVERE THUNDERSTORM CANNOT BE RULED OUT WHERE BOUNDARY
INTERACTIONS OCCUR. OTHERWISE...THE MAIN HAZARD ASSOCIATED WITH
THUNDERSTORMS WILL BE HEAVY DOWNPOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
DIURNAL CONVECTION WILL TAPER OFF EARLY THIS EVENING OVER
LAND...WHILE ISOLATED SHOWERS OR STORMS WILL REMAIN POSSIBLE OVER
THE COASTAL WATERS TONIGHT. SOME FOG IS POSSIBLE LATE
TONIGHT/EARLY THURSDAY MORNING...ESPECIALLY IN AREAS WHERE RAIN
OCCURS TODAY.
THURSDAY...ATLANTIC HIGH PRESSURE WILL PREVAIL WHILE WEAK TROUGHING
PERSISTS INLAND. A SHORTWAVE EMBEDDED WITHIN BROAD UPPER LEVEL
TROUGHING WILL CROSS THE REGION AND PUSH THE DEEP LAYERED MOISTURE
OFFSHORE AS THE DAY PROGRESSES. THERE IS THE POTENTIAL FOR ISOLATED
CONVECTION ACROSS THE AREA IN THE MORNING AHEAD OF THE SHORT
WAVE...WITH THE COVERAGE INCREASING TO SCATTERED IN THE AFTERNOON
ACROSS MUCH OF SOUTHEAST SOUTH CAROLINA WHERE PRECIPITABLE WATER
VALUES AND LOW LEVEL CONVERGENCE WILL BE MAXIMIZED. A
WESTERLY/DOWNSLOPE FLOW ALOFT WILL PUSH TEMPERATURES TO HIGHS IN THE
UPPER 80S TO AROUND 90 AWAY FROM THE IMMEDIATE COAST.
THURSDAY NIGHT...AN UPPER LEVEL TROUGH WILL DIG TOWARD THE
APPALACHIANS...PUSHING A COLD FRONT ACROSS THE AREA. OTHER THAN SOME
ISOLATED CONVECTION EARLY IN THE EVENING MAINLY ACROSS THE
CHARLESTON TRI-COUNTY AREA...THE FRONT SHOULD PASS THROUGH RELATIVE
RAIN-FREE DUE TO A LACK OF DEEP LAYERED MOISTURE. LOWS WILL BE IN
THE LOWER TO MID 60S.
FRIDAY...THE UPPER LEVEL TROUGH WILL MOVE OVER THE MID-ATLANTIC AS
SURFACE HIGH PRESSURE BEGINS TO BUILD IN FROM THE GREAT LAKES REGION
IN WAKE OF THE DEPARTING COLD FRONT. MUCH DRIER AIR WILL FILTER INTO
THE AREA WITH A STRONG NORTHWEST/DOWNSLOPE WIND COMPONENT. THERE
WILL BE CONSIDERABLE SUNSHINE ALONG WITH BREEZY CONDITIONS IN THE
AFTERNOON. THE DOWNSLOPE FLOW WILL NEGATE MUCH OF THE COLD AIR
ADVECTION...ALLOWING TEMPERATURES TO REACH HIGHS IN THE MID AND
UPPER 80S ACROSS THE AREA AWAY FROM THE IMMEDIATE COAST.
FRIDAY NIGHT...RADIATIONAL COOLING WILL BE LIMITED BY A COUPLED
NORTHERLY FLOW THROUGH MUCH OF THE NIGHT...BUT THE DRY AIR MASS AND
CLEAR SKIES SHOULD STILL ALLOW TEMPERATURES TO FALL INTO THE THE MID
AND UPPER 50S...WITH SOME LOWER 50S POSSIBLE WELL INLAND.
SATURDAY...AN EXTREMELY DRY AIR MASS WILL BE IN PLACE TO START THE
WEEKEND...WITH PRECIPITABLE WATER VALUES AS LOW AS .25 TO .50 INCHES
WHICH IS MORE THAN 2 STANDARD DEVIATIONS BELOW NORMAL FOR THIS TIME
OF YEAR. GIVEN THIS DRY AIR MASS...THERE WILL BE CONSIDERABLE
SUNSHINE BUT A NORTH-NORTHEAST FLOW WILL LIMIT HIGHS TO THE UPPER
70S TO LOWER 80S ACROSS SOUTHEAST SOUTH CAROLINA AND THE LOWER TO
MID 80S ACROSS SOUTHEAST GEORGIA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
ISOLATED CONVECTION IS EXPECTED TO DEVELOP IN THE VICINITY OF THE
TERMINALS BY LATE MORNING/EARLY AFTERNOON ALONG THE SEA
BREEZE...THEN SHIFT INLAND OF THE TERMINALS LATER THIS AFTERNOON.
COVERAGE/TIMING UNCERTAINTIES PRECLUDE ANY MENTION IN THE TAFS
OTHER THAN VICINITY SHOWERS THROUGH MID-AFTERNOON AT KCHS AND LATE
AFTERNOON AT KSAV. ABUNDANT LOW LEVEL MOISTURE COULD RESULT IN
SOME REDUCED CEILINGS/VISIBILITIES LATE TONIGHT.
EXTENDED AVIATION...ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH
THURSDAY. A COLD FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT
WITH HIGH PRESSURE THEN BUILDING OVER THE REGION THROUGH EARLY
NEXT WEEK.
&&
.MARINE...
MARINE CONDITIONS WILL BE FAIRLY BENIGN THROUGH TONIGHT...AS THE
AREA REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE.
THE SEABREEZE WILL DEVELOP BY LATE MORNING...HOWEVER WIND SPEEDS
AT THE COAST ARE STILL EXPECTED TO GENERALLY REMAIN BELOW 15 KT.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WMS
SHORT TERM...JAQ
LONG TERM...JAQ
AVIATION...JAQ
MARINE...JAQ/JRL
TIDES/COASTAL FLOODING...WMS
000
FXUS62 KCAE 221419
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1019 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CONTINUE TO CIRCULATE
MOIST AIR INTO THE FORECAST AREA THIS AFTERNOON. THE NAM AND GFS
CONTINUE TO INDICATE A WEAK MID-LEVEL SHORTWAVE TROUGH LINGERING
OVER THE FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS MAINLY
DURING THE TIME OF MAXIMUM HEATING. USED AN AVERAGE OF THE GFS AND
NAM MOS POPS. PRECIPITABLE WATER NEAR 1.7 OF AN INCH AND SLOW
STORM MOVEMENT SUPPORTS HEAVY RAIN WILL SOME OF THE THUNDERSTORMS.
HEAVY PRECIPITATION LOADINGS AND POSSIBLY MODERATE INSTABILITY
WITH H5 TEMPERATURES AROUND -10 SUPPORT A POSSIBILITY OF DAMAGING
WIND. USED THE WARMER TEMPERATURE GUIDANCE FOR THIS AFTERNOON BASED
ON YESTERDAY/S VERIFICATION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A CONTINUED MOIST SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH
PLUS A PRE-FRONTAL TROUGH SUPPORT THUNDERSTORMS TONIGHT. COVERAGE
WILL LIKELY BE LIMITED BY DIURNAL COOLING AND PREVIOUS CONVECTION.
THE NAM AND GFS MOS ARE IN GOOD AGREEMENT WITH POPS 30 TO 40 PERCENT.
THE MODELS SHOW THE PRE-FRONTAL TROUGH LINGERING THURSDAY BUT
DEEPER MOISTURE APPEARS TO SHIFT EAST OF THE FORECAST AREA EARLY
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE NAM AND GFS MOS
INDICATE VERY LOW POPS...BUT MAINTAINED CHANCE POPS BECAUSE OF
CONVERGENCE ASSOCIATED WITH THE PRE-FRONTAL TROUGH THURSDAY AND
THE COLD FRONT THURSDAY EVENING. FURTHER DRYING SHOULD OCCUR
BEHIND THE FRONT BY LATE THURSDAY NIGHT. THE TEMPERATURE GUIDANCE
WAS CLOSE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
AND TUESDAY. THE GFS AND ECMWF MOS PLUS GFS ENSEMBLE MEAN SUPPORTS
VERY LOW POPS. EXPECT BELOW NORMAL TEMPERATURES DURING THE
WEEKEND AND NEAR NORMAL DURING THE REST OF THE MEDIUM RANGE
PERIOD.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
EXPECT PERIODS OF MVFR/IFR AT MOST OF THE TAF SITES UNTIL AROUND 16Z.
STRATUS EXPECTED TO LIFT/DIMINISH BY MIDDAY. LOW LEVEL MOISTURE
WILL REMAIN HIGH. MAINLY VFR CONDITIONS THIS AFTERNOON WITH
SCATTERED THUNDERSTORMS DEVELOPING AFTER 18Z. GIVEN THE EXPECTED
SCATTERED NATURE OF THE CONVECTION...NOT ENOUGH CONFIDENCE TO
MENTION THUNDER IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND THUNDERSTORMS...
MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH FRIDAY. LATE NIGHT/EARLY
MORNING FOG/STRATUS ALSO POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 221318
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
918 AM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD
FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT...WITH HIGH
PRESSURE BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAK UPPER TROUGH WILL PERSIST OVER THE REGION AGAIN
TODAY...WHILE ATLANTIC SURFACE HIGH PRESSURE EXTENDS INTO THE
SOUTHEAST STATES. DEEP LAYER MOISTURE REMAINS IN PLACE...WITH
PRECIPITABLE WATER VALUES AROUND 1.5 INCHES ACCORDING TO THE
UPPER AIR SOUNDINGS AT CHS AND JAX. DEEP LAYERED SOUTHERLY FLOW
WILL ALLOW THE SEABREEZE TO DEVELOP FAIRLY EARLY. WITH
TEMPERATURES PEAKING IN THE MID TO UPPER 80S...MODERATE
INSTABILITY WILL DEVELOP BY LATE MORNING/EARLY AFTERNOON. SHOWERS
AND THUNDERSTORMS WILL THUS INCREASE IN COVERAGE FROM LATE MORNING
INTO THE AFTERNOON...WITH THE ACTIVITY LIKELY SHIFTING GRADUALLY
INLAND FOLLOWING THE MOVEMENT OF THE SEABREEZE. CONVECTIVE
PARAMETERS ARE NOT IMPRESSIVE...HOWEVER AN ISOLATED SEVERE STORM
CANNOT BE RULED OUT WHERE BOUNDARY INTERACTIONS OCCUR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
DIURNAL CONVECTION WILL TAPER OFF EARLY THIS EVENING OVER
LAND...WHILE ISOLATED SHOWERS OR STORMS WILL REMAIN POSSIBLE OVER
THE COASTAL WATERS TONIGHT. SOME FOG IS POSSIBLE LATE
TONIGHT/EARLY THURSDAY MORNING...ESPECIALLY IN AREAS WHERE RAIN
OCCURS TODAY.
THURSDAY...ATLANTIC HIGH PRESSURE WILL PREVAIL WHILE WEAK TROUGHING
PERSISTS INLAND. A SHORTWAVE EMBEDDED WITHIN BROAD UPPER LEVEL
TROUGHING WILL CROSS THE REGION AND PUSH THE DEEP LAYERED MOISTURE
OFFSHORE AS THE DAY PROGRESSES. THERE IS THE POTENTIAL FOR ISOLATED
CONVECTION ACROSS THE AREA IN THE MORNING AHEAD OF THE SHORT
WAVE...WITH THE COVERAGE INCREASING TO SCATTERED IN THE AFTERNOON
ACROSS MUCH OF SOUTHEAST SOUTH CAROLINA WHERE PRECIPITABLE WATER
VALUES AND LOW LEVEL CONVERGENCE WILL BE MAXIMIZED. A
WESTERLY/DOWNSLOPE FLOW ALOFT WILL PUSH TEMPERATURES TO HIGHS IN THE
UPPER 80S TO AROUND 90 AWAY FROM THE IMMEDIATE COAST.
THURSDAY NIGHT...AN UPPER LEVEL TROUGH WILL DIG TOWARD THE
APPALACHIANS...PUSHING A COLD FRONT ACROSS THE AREA. OTHER THAN SOME
ISOLATED CONVECTION EARLY IN THE EVENING MAINLY ACROSS THE
CHARLESTON TRI-COUNTY AREA...THE FRONT SHOULD PASS THROUGH RELATIVE
RAIN-FREE DUE TO A LACK OF DEEP LAYERED MOISTURE. LOWS WILL BE IN
THE LOWER TO MID 60S.
FRIDAY...THE UPPER LEVEL TROUGH WILL MOVE OVER THE MID-ATLANTIC AS
SURFACE HIGH PRESSURE BEGINS TO BUILD IN FROM THE GREAT LAKES REGION
IN WAKE OF THE DEPARTING COLD FRONT. MUCH DRIER AIR WILL FILTER INTO
THE AREA WITH A STRONG NORTHWEST/DOWNSLOPE WIND COMPONENT. THERE
WILL BE CONSIDERABLE SUNSHINE ALONG WITH BREEZY CONDITIONS IN THE
AFTERNOON. THE DOWNSLOPE FLOW WILL NEGATE MUCH OF THE COLD AIR
ADVECTION...ALLOWING TEMPERATURES TO REACH HIGHS IN THE MID AND
UPPER 80S ACROSS THE AREA AWAY FROM THE IMMEDIATE COAST.
FRIDAY NIGHT...RADIATIONAL COOLING WILL BE LIMITED BY A COUPLED
NORTHERLY FLOW THROUGH MUCH OF THE NIGHT...BUT THE DRY AIR MASS AND
CLEAR SKIES SHOULD STILL ALLOW TEMPERATURES TO FALL INTO THE THE MID
AND UPPER 50S...WITH SOME LOWER 50S POSSIBLE WELL INLAND.
SATURDAY...AN EXTREMELY DRY AIR MASS WILL BE IN PLACE TO START THE
WEEKEND...WITH PRECIPITABLE WATER VALUES AS LOW AS .25 TO .50 INCHES
WHICH IS MORE THAN 2 STANDARD DEVIATIONS BELOW NORMAL FOR THIS TIME
OF YEAR. GIVEN THIS DRY AIR MASS...THERE WILL BE CONSIDERABLE
SUNSHINE BUT A NORTH-NORTHEAST FLOW WILL LIMIT HIGHS TO THE UPPER
70S TO LOWER 80S ACROSS SOUTHEAST SOUTH CAROLINA AND THE LOWER TO
MID 80S ACROSS SOUTHEAST GEORGIA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
ISOLATED CONVECTION IS EXPECTED TO DEVELOP IN THE VICINITY OF THE
TERMINALS LATE THIS MORNING ALONG THE SEA BREEZE...THEN SHIFT
INLAND OF THE TERMINALS LATER THIS AFTERNOON. COVERAGE/TIMING
UNCERTAINTIES PRECLUDE ANY MENTION IN THE TAFS OTHER THAN
VICINITY SHOWERS THROUGH MID-AFTERNOON AT KCHS AND LATE AFTERNOON
AT KSAV. ABUNDANT LOW LEVEL MOISTURE COULD RESULT IN SOME REDUCED
CEILINGS/VISIBILITIES LATE TONIGHT.
EXTENDED AVIATION...ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH
THURSDAY. A COLD FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT
WITH HIGH PRESSURE THEN BUILDING OVER THE REGION THROUGH EARLY
NEXT WEEK.
&&
.MARINE...
MARINE CONDITIONS LOOK PRETTY QUIET THROUGH TONIGHT AS THE AREA
REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE. THE
SEABREEZE SHOULD DEVELOP LATE THIS MORNING...BUT WIND SPEEDS AT
THE COAST ARE STILL EXPECTED TO GENERALLY REMAIN BELOW 15 KT.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD FRONT
WILL MOVE ACROSS THE AREA THURSDAY NIGHT WITH HIGH PRESSURE THEN
BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...WMS/JRL
SHORT TERM...JAQ
LONG TERM...JAQ
AVIATION...JAQ
MARINE...JAQ/JRL
TIDES/COASTAL FLOODING...
000
FXUS62 KCHS 221153
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
753 AM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD FRONT
WILL MOVE ACROSS THE AREA THURSDAY NIGHT WITH HIGH PRESSURE THEN
BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A DENSE FOG ADVISORY IS IN EFFECT FOR PARTS OF THE AREA THROUGH 9
AM AS VISIBILITIES HAVE FALLEN TO 1/4 MILE OR LESS IN AREAS MAINLY
WEST OF THE I-95 CORRIDOR. VISIBILITIES WILL GRADUALLY IMPROVE
THROUGH MID-MORNING.
WEAK SHORTWAVE TROUGHING AT UPPER LEVELS TO PERSIST TODAY WHILE
ATLANTIC HIGH PRESSURE EXTENDS WEST INTO THE SOUTHEAST STATES AT
THE SURFACE. THE IN-SITU AIRMASS REMAINS QUITE MOIST WITH PW
VALUES HOVERING AT OR ABOVE 1.60 INCHES. A FEW SHOWERS ARE
POSSIBLE OVER THE COASTAL WATERS AND IMMEDIATE SC COAST MAINLY
NORTHEAST OF CHARLESTON IN SOME WEAK MOISTURE CONVERGENCE THROUGH
MID-MORNING. THEN...THE DEEP-LAYERED SOUTHEAST FLOW WILL ALLOW
THE SEABREEZE TO DEVELOP FAIRLY EARLY. WITH TEMPS PUSHING INTO THE
MIDDLE TO UPPER 80S...MODERATE INSTABILITY WILL DEVELOP YET AGAIN.
SHOWERS AND TSTMS WILL INCREASE IN COVERAGE FROM LATE MORNING INTO
THE AFTERNOON WITH THE ACTIVITY LIKELY SHIFTING GRADUALLY INLAND.
CONVECTIVE PARAMETERS ARE NOT TERRIBLY IMPRESSIVE BUT AN ISOLATED
SEVERE STORM OR TWO CANNOT BE RULED OUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
DIURNAL CONVECTION WILL TAPER OFF EARLY THIS EVENING OVER LAND BUT
ISOLATED SHOWERS OR STORMS WILL REMAIN POSSIBLE OVER THE COASTAL
WATERS OVERNIGHT. SOME FOG IS POSSIBLE LATE TONIGHT...ESPECIALLY
IN AREAS WHERE RAIN OCCURS TODAY.
THURSDAY...ATLANTIC HIGH PRESSURE WILL PREVAIL WHILE WEAK TROUGHING
PERSISTS INLAND. A SHORTWAVE EMBEDDED WITHIN BROAD UPPER LEVEL
TROUGHING WILL CROSS THE REGION AND PUSH THE DEEP LAYERED MOISTURE
OFFSHORE AS THE DAY PROGRESSES. THERE IS THE POTENTIAL FOR ISOLATED
CONVECTION ACROSS THE AREA IN THE MORNING AHEAD OF THE SHORT
WAVE...WITH THE COVERAGE INCREASING TO SCATTERED IN THE AFTERNOON
ACROSS MUCH OF SOUTHEAST SOUTH CAROLINA WHERE PRECIPITABLE WATER
VALUES AND LOW LEVEL CONVERGENCE WILL BE MAXIMIZED. A
WESTERLY/DOWNSLOPE FLOW ALOFT WILL PUSH TEMPERATURES TO HIGHS IN THE
UPPER 80S TO AROUND 90 AWAY FROM THE IMMEDIATE COAST.
THURSDAY NIGHT...AN UPPER LEVEL TROUGH WILL DIG TOWARD THE
APPALACHIANS...PUSHING A COLD FRONT ACROSS THE AREA. OTHER THAN SOME
ISOLATED CONVECTION EARLY IN THE EVENING MAINLY ACROSS THE
CHARLESTON TRI-COUNTY AREA...THE FRONT SHOULD PASS THROUGH RELATIVE
RAIN-FREE DUE TO A LACK OF DEEP LAYERED MOISTURE. LOWS WILL BE IN
THE LOWER TO MID 60S.
FRIDAY...THE UPPER LEVEL TROUGH WILL MOVE OVER THE MID-ATLANTIC AS
SURFACE HIGH PRESSURE BEGINS TO BUILD IN FROM THE GREAT LAKES REGION
IN WAKE OF THE DEPARTING COLD FRONT. MUCH DRIER AIR WILL FILTER INTO
THE AREA WITH A STRONG NORTHWEST/DOWNSLOPE WIND COMPONENT. THERE
WILL BE CONSIDERABLE SUNSHINE ALONG WITH BREEZY CONDITIONS IN THE
AFTERNOON. THE DOWNSLOPE FLOW WILL NEGATE MUCH OF THE COLD AIR
ADVECTION...ALLOWING TEMPERATURES TO REACH HIGHS IN THE MID AND
UPPER 80S ACROSS THE AREA AWAY FROM THE IMMEDIATE COAST.
FRIDAY NIGHT...RADIATIONAL COOLING WILL BE LIMITED BY A COUPLED
NORTHERLY FLOW THROUGH MUCH OF THE NIGHT...BUT THE DRY AIRMASS AND
CLEAR SKIES SHOULD STILL ALLOW TEMPERATURES TO FALL INTO THE THE MID
AND UPPER 50S...WITH SOME LOWER 50S POSSIBLE WELL INLAND.
SATURDAY...AN EXTREMELY DRY AIRMASS WILL BE IN PLACE TO START THE
WEEKEND...WITH PRECIPITABLE WATER VALUES AS LOW AS .25 TO .50 INCHES
WHICH IS MORE THAN 2 STANDARD DEVIATIONS BELOW NORMAL FOR THIS TIME
OF YEAR. GIVEN THIS DRY AIRMASS...THERE WILL BE CONSIDERABLE
SUNSHINE BUT A NORTH-NORTHEAST FLOW WILL LIMIT HIGHS TO THE UPPER
70S TO LOWER 80S ACROSS SOUTHEAST SOUTH CAROLINA AND THE LOWER TO
MID 80S ACROSS SOUTHEAST GEORGIA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
ISOLATED CONVECTION IS EXPECTED TO DEVELOP IN THE VICINITY OF THE
TERMINALS LATE THIS MORNING ALONG THE SEA BREEZE...THEN SHIFT
INLAND OF THE TERMINALS LATER THIS AFTERNOON. COVERAGE/TIMING
UNCERTAINTIES PRECLUDE ANY MENTION IN THE TAF/S OTHER THAN
VICINITY SHOWERS THROUGH MID-AFTERNOON AT KCHS AND LATE AFTERNOON
AT KSAV. ABUNDANT LOW LEVEL MOISTURE COULD RESULT IN SOME REDUCED
CEILINGS/VISIBILITIES LATE TONIGHT.
EXTENDED AVIATION...ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH
THURSDAY. A COLD FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT
WITH HIGH PRESSURE THEN BUILDING OVER THE REGION THROUGH EARLY
NEXT WEEK.
&&
.MARINE...
MARINE CONDITIONS LOOK PRETTY QUIET THROUGH TONIGHT AS THE AREA
REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE. THE
SEABREEZE SHOULD DEVELOP LATE THIS MORNING BUT WIND SPEEDS AT THE
COAST ARE NOT EXPECTED TO BE TERRIBLY IMPRESSIVE.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD FRONT
WILL MOVE ACROSS THE AREA THURSDAY NIGHT WITH HIGH PRESSURE THEN
BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088-
099>101-114>116-137-138-140.
SC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ040-042.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JRL
SHORT TERM...JAQ
LONG TERM...JAQ
AVIATION...JAQ
MARINE...JRL/JAQ
TIDES/COASTAL FLOODING...
000
FXUS62 KFFC 221151
AFDFFC
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
745 AM EDT WED MAY 22 2013
.SHORT TERM /TODAY THROUGH THURSDAY/...
UPPER TROUGH WILL MOVE THROUGH THE UPPER MISSISSIPPI VALLEY TODAY
INTO TONIGHT. AN ASSOCIATED SHORT WAVE TRAILING INTO THE SOUTHERN
STATES WILL HELP FOCUS SHOWERS AND THUNDERSTORMS ACROSS THE CWA
THROUGH TONIGHT. AREA OF THUNDERSTORMS CURRENTLY MOVING INTO ALABAMA
MAY REACH NORTHWEST GEORGIA BY SUNRISE IF THEY HOLD TOGETHER. THIS
COMBINED WITH VARIOUS OUTFLOW BOUNDARIES WILL MAKE TIMING OF
CONVECTION DIFFICULT. HOWEVER THE BEST CHANCES WOULD SEEM TO BE THIS
AFTERNOON AND EVENING WITH DIURNAL HEATING. HAVE CONTINUED WITH THE
SEVERE WORDING ACROSS PORTIONS OF NORTH THIS AFTERNOON. THIS FITS
WELL WITH THE SPC SLIGHT RISK AREA. DIMINISHING POPS OVERNIGHT AS
THE SHORT WAVE MOVES INTO THE CAROLINAS. SOME DRYING INDICATED FOR
THURSDAY BUT WITH APPROACHING UPPER TROUGH...HAVE LEFT LOW POPS IN
ACROSS THE CWA. BASED ON TUESDAYS TEMPERATURES...HAVE STAYED ON THE
WARM SIDE OF MAV/MET. HOWEVER WITH ADDITIONAL CLOUDS AND
PRECIPITATION EXPECTED FOR TODAY...TEMPERATURES MAY VARY MORE ACROSS
THE CWA.
41
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A WEAK COLD FRONT AND MAIN UPPER SUPPORT WILL BE EXITING THE AREA
THURSDAY NIGHT. IT IS UNCLEAR HOW MUCH CONVECTIVE ACTIVITY THERE
WILL BE WITH THE GFS AND NAM INDICATING LITTLE OR NO MEASURABLE
RAIN AMOUNTS. LOOKS LIKE NO MORE THAN A SLIGHT CHANCE OF SHOWERS OR
THUNDERSTORMS FOR THE FIRST PART OF THURSDAY NIGHT.
MUCH DRIER AIRMASS MOVES OVER THE AREA ON FRIDAY WITH DRY NW FLOW
ALOFT AND SURFACE HIGH PRESSURE BUILDING OVER THE OH/TN VALLEYS
DURING THE DAY. GRADIENT WINDS WILL INCREASE GETTING CLOSE TO WIND
ADVISORY CRITERIA(20 MPH SUSTAINED) FOR SOME AREAS. DRY CONDITIONS
CONTINUE SATURDAY AND MOSTLY SUNDAY. HOWEVER THE NW FLOW ALOFT N OF
THE AREA IS BECOMING MORE ACTIVE WITH PRECIP CHANCES AND WHILE THE
GFS IS DRY FOR OUR AREA ON SUNDAY...MOISTURE IS SKIRTING NE GA. THE
EUROPEAN MEANWHILE IS INDICATING LIGHT PRECIP AMOUNTS OVER FAR N AND
E GA ON SUNDAY. A SIMILAR PATTERN CONTINUES FOR MONDAY AND TUESDAY
AS WELL. HIGH PRESSURE ALOFT BUILDS FOR WEDNESDAY AND EVEN WILL
SOUTHERLY FLOW OVER THE AREA...HIGH PRESSURE ALOFT WILL KEEP ANY
PRECIP CHANCES TO A MINIMUM. FOR NOW WILL FAVOR THE DRIER GFS.
TEMPERATURES GENERALLY RUNNING WITHIN 5 DEGREES OF NORMAL THROUGH
THE PERIOD EXCEPT SATURDAY MORNING LOWS ARE RUNNING 10-15 DEGREES
BELOW NORMAL AND SUNDAY MORNING LOWS ARE RUNNING CLOSE TO 10
DEGREES BELOW NORMAL.
BDL
&&
.AVIATION...
12Z UPDATE...
EXPECTING VFR TODAY OUTSIDE OF AREAS OF SHOWERS/THUNDERSTORMS. THERE
MAY BE CONVECTION AROUND THE FORECAST AREA MUCH OF THE DAY BUT THE
BEST CHANCE FOR THUNDER AT ANY OF THE TAF SITES APPEARS TO BE 18Z
AND INTO THE EARLY EVENING UNTIL AROUND 02Z. VARIABLE TO LIGHT
SOUTHEAST WINDS THIS MORNING BECOMING SOUTHWEST 10KT AFTER 14Z.
VARIABLE TO GUSTY WINDS IN THUNDERSTORMS.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF CONVECTION.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 65 87 59 / 40 40 30 20
ATLANTA 86 66 85 60 / 50 40 30 20
BLAIRSVILLE 80 61 80 55 / 60 60 30 20
CARTERSVILLE 84 63 84 57 / 60 60 30 20
COLUMBUS 90 67 89 63 / 30 30 30 20
GAINESVILLE 85 65 83 57 / 50 50 30 20
MACON 90 65 89 61 / 30 30 30 10
ROME 84 63 85 57 / 60 60 30 20
PEACHTREE CITY 86 62 86 59 / 40 30 30 20
VIDALIA 88 67 89 67 / 30 30 30 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41
LONG TERM....BDL
AVIATION...41
000
FXUS62 KCAE 221046
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
646 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH LOW-LEVEL MOISTURE HAS HELPED CAUSE AREAS OF STRATUS AND FOG
EARLY THIS MORNING. DENSE FOG WAS OCCURRING IN PARTS OF THE AREA.
WE HAVE ISSUED A DENSE FOG ADVISORY FOR EARLY THIS MORNING.
DIURNAL HEATING SHOULD BEGIN TO DIMINISH ANY FOG BY 900 AM.
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CONTINUE TO CIRCULATE
MOIST AIR INTO THE FORECAST AREA TODAY. THE NAM AND GFS CONTINUE TO
INDICATE A WEAK MID-LEVEL SHORTWAVE TROUGH LINGERING OVER THE
FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS MAINLY DURING THE
TIME OF MAXIMUM HEATING. USED AN AVERAGE OF THE GFS AND NAM MOS
POPS. PRECIPITABLE WATER NEAR 1.7 OF AN INCH AND SLOW STORM
MOVEMENT SUPPORTS HEAVY RAIN WILL SOME OF THE THUNDERSTORMS. HEAVY
PRECIPITATION LOADINGS AND POSSIBLY MODERATE INSTABILITY WITH H5
TEMPERATURES AROUND -10 SUPPORT A POSSIBILITY OF DAMAGING WIND.
USED THE WARMER TEMPERATURE GUIDANCE FOR TODAY BASED ON
YESTERDAY/S VERIFICATION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A CONTINUED MOIST SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH
PLUS A PRE-FRONTAL TROUGH SUPPORT THUNDERSTORMS TONIGHT. COVERAGE
WILL LIKELY BE LIMITED BY DIURNAL COOLING AND PREVIOUS CONVECTION.
THE NAM AND GFS MOS ARE IN GOOD AGREEMENT WITH POPS 30 TO 40 PERCENT.
THE MODELS SHOW THE PRE-FRONTAL TROUGH LINGERING THURSDAY BUT
DEEPER MOISTURE APPEARS TO SHIFT EAST OF THE FORECAST AREA EARLY
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE NAM AND GFS MOS
INDICATE VERY LOW POPS...BUT MAINTAINED CHANCE POPS BECAUSE OF
CONVERGENCE ASSOCIATED WITH THE PRE-FRONTAL TROUGH THURSDAY AND
THE COLD FRONT THURSDAY EVENING. FURTHER DRYING SHOULD OCCUR
BEHIND THE FRONT BY LATE THURSDAY NIGHT. THE TEMPERATURE GUIDANCE
WAS CLOSE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
AND TUESDAY. THE GFS AND ECMWF MOS PLUS GFS ENSEMBLE MEAN SUPPORTS
VERY LOW POPS. EXPECT BELOW NORMAL TEMPERATURES DURING THE
WEEKEND AND NEAR NORMAL DURING THE REST OF THE MEDIUM RANGE
PERIOD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
EXPECT PERIODS OF MVFR/IFR AT MOST OF THE TAF SITES UNTIL AROUND
13Z...WITH POSSIBLE LIFR AT AGS. STRATUS AND FOG EXPECTED TO BURN
OFF DURING THE EARLY TO MID MORNING. LOW LEVEL MOISTURE WILL
REMAIN HIGH. VFR CONDITIONS DURING THE LATE MORNING AND AFTERNOON
WITH SCATTERED THUNDERSTORMS DEVELOPING AFTER 18Z. GIVEN THE
EXPECTED SCATTERED NATURE OF THE CONVECTION...NOT ENOUGH
CONFIDENCE TO MENTION THUNDER IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH
FRIDAY. LATE NIGHT/EARLY MORNING FOG/STRATUS ALSO POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
GA...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ040-
063>065-077.
&&
$$
000
FXUS62 KCAE 221009
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
609 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH LOW-LEVEL MOISTURE AND LIGHT WIND HAS HELPED CAUSE AREAS OF
FOG EARLY THIS MORNING. DENSE FOG WAS REPORTED AT AUGUSTA AND
ORANGEBURG. WE HAVE ISSUED A DENSE FOG ADVISORY FOR THE SOUTH PART
FOR EARLY THIS MORNING. DIURNAL HEATING SHOULD BEGIN TO DIMINISH
THE FOG BY 900 AM.
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CONTINUE TO CIRCULATE
MOIST AIR INTO THE FORECAST AREA TODAY. THE NAM AND GFS CONTINUE TO
INDICATE A WEAK MID-LEVEL SHORTWAVE TROUGH LINGERING OVER THE
FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS MAINLY DURING THE
TIME OF MAXIMUM HEATING. USED AN AVERAGE OF THE GFS AND NAM MOS
POPS. PRECIPITABLE WATER NEAR 1.7 OF AN INCH AND SLOW STORM
MOVEMENT SUPPORTS HEAVY RAIN WILL SOME OF THE THUNDERSTORMS. HEAVY
PRECIPITATION LOADINGS AND POSSIBLY MODERATE INSTABILITY WITH H5
TEMPERATURES AROUND -10 SUPPORT A POSSIBILITY OF DAMAGING WIND.
USED THE WARMER TEMPERATURE GUIDANCE FOR TODAY BASED ON
YESTERDAY/S VERIFICATION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A CONTINUED MOIST SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH
PLUS A PRE-FRONTAL TROUGH SUPPORT THUNDERSTORMS TONIGHT. COVERAGE
WILL LIKELY BE LIMITED BY DIURNAL COOLING AND PREVIOUS CONVECTION.
THE NAM AND GFS MOS ARE IN GOOD AGREEMENT WITH POPS 30 TO 40 PERCENT.
THE MODELS SHOW THE PRE-FRONTAL TROUGH LINGERING THURSDAY BUT
DEEPER MOISTURE APPEARS TO SHIFT EAST OF THE FORECAST AREA EARLY
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE NAM AND GFS MOS
INDICATE VERY LOW POPS...BUT MAINTAINED CHANCE POPS BECAUSE OF
CONVERGENCE ASSOCIATED WITH THE PRE-FRONTAL TROUGH THURSDAY AND
THE COLD FRONT THURSDAY EVENING. FURTHER DRYING SHOULD OCCUR
BEHIND THE FRONT BY LATE THURSDAY NIGHT. THE TEMPERATURE GUIDANCE
WAS CLOSE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
AND TUESDAY. THE GFS AND ECMWF MOS PLUS GFS ENSEMBLE MEAN SUPPORTS
VERY LOW POPS. EXPECT BELOW NORMAL TEMPERATURES DURING THE
WEEKEND AND NEAR NORMAL DURING THE REST OF THE MEDIUM RANGE
PERIOD.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
EXPECT PERIODS OF MVFR/IFR AT MOST OF THE TAF SITES UNTIL AROUND
13Z...WITH POSSIBLE LIFR AT AGS. STRATUS AND FOG EXPECTED TO BURN
OFF DURING THE EARLY TO MID MORNING. LOW LEVEL MOISTURE WILL
REMAIN HIGH. VFR CONDITIONS DURING THE LATE MORNING AND AFTERNOON
WITH SCATTERED THUNDERSTORMS DEVELOPING AFTER 18Z. GIVEN THE
EXPECTED SCATTERED NATURE OF THE CONVECTION...NOT ENOUGH
CONFIDENCE TO MENTION THUNDER IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH
FRIDAY. LATE NIGHT/EARLY MORNING FOG/STRATUS ALSO POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ030-
035>038-041.
GA...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ063>065-
077.
&&
$$
000
FXUS62 KCAE 220914
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
514 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH LOW-LEVEL MOISTURE AND LIGHT WIND HAS HELPED CAUSE AREAS OF
FOG EARLY THIS MORNING. DENSE FOG WAS REPORTED AT AUGUSTA AND
ORANGEBURG. WE HAVE ISSUED A DENSE FOG ADVISORY FOR THE SOUTH PART
FOR EARLY THIS MORNING. DIURNAL HEATING SHOULD BEGIN TO DIMINISH
THE FOG BY 900 AM.
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CONTINUE TO CIRCULATE
MOIST AIR INTO THE FORECAST AREA TODAY. THE NAM AND GFS CONTINUE TO
INDICATE A WEAK MID-LEVEL SHORTWAVE TROUGH LINGERING OVER THE
FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS MAINLY DURING THE
TIME OF MAXIMUM HEATING. USED AN AVERAGE OF THE GFS AND NAM MOS
POPS. PRECIPITABLE WATER NEAR 1.7 OF AN INCH AND SLOW STORM
MOVEMENT SUPPORTS HEAVY RAIN WILL SOME OF THE THUNDERSTORMS. HEAVY
PRECIPITATION LOADINGS AND POSSIBLY MODERATE INSTABILITY WITH H5
TEMPERATURES AROUND -10 SUPPORT A POSSIBILITY OF DAMAGING WIND.
USED THE WARMER TEMPERATURE GUIDANCE FOR TODAY BASED ON
YESTERDAY/S VERIFICATION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A CONTINUED MOIST SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH
PLUS A PRE-FRONTAL TROUGH SUPPORT THUNDERSTORMS TONIGHT. COVERAGE
WILL LIKELY BE LIMITED BY DIURNAL COOLING AND PREVIOUS CONVECTION.
THE NAM AND GFS MOS ARE IN GOOD AGREEMENT WITH POPS 30 TO 40 PERCENT.
THE MODELS SHOW THE PRE-FRONTAL TROUGH LINGERING THURSDAY BUT
DEEPER MOISTURE APPEARS TO SHIFT EAST OF THE FORECAST AREA EARLY
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE NAM AND GFS MOS
INDICATE VERY LOW POPS...BUT MAINTAINED CHANCE POPS BECAUSE OF
CONVERGENCE ASSOCIATED WITH THE PRE-FRONTAL TROUGH THURSDAY AND
THE COLD FRONT THURSDAY EVENING. FURTHER DRYING SHOULD OCCUR
BEHIND THE FRONT BY LATE THURSDAY NIGHT. THE TEMPERATURE GUIDANCE
WAS CLOSE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
AND TUESDAY. THE GFS AND ECMWF MOS PLUS GFS ENSEMBLE MEAN SUPPORTS
VERY LOW POPS. EXPECT BELOW NORMAL TEMPERATURES DURING THE
WEEKEND AND NEAR NORMAL DURING THE REST OF THE MEDIUM RANGE
PERIOD.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
EXPECT SCATTERED TO BROKEN MID AND HIGH LEVEL CLOUDS SHOULD DIMINISH
DURING THE EARLY MORNING HOURS. WITH CLEARING SKIES EXPECT AREAS OF
FOG AND STRATUS TO DEVELOP WHERE MOST OF THE RAIN FELL YESTERDAY.
EXPECT PERIODS OF MVFR/IFR AT MOST OF THE TAF SITES UNTIL AROUND
13Z...WITH POSSIBLE LIFR AT AGS. STRATUS AND FOG EXPECTED TO BURN
OFF DURING THE EARLY TO MID MORNING. LOW LEVEL MOISTURE WILL REMAIN
HIGH. VFR CONDITIONS DURING THE LATE MORNING AND AFTERNOON WITH
SCATTERED THUNDERSTORMS DEVELOPING AFTER 18Z. GIVEN THE EXPECTED
SCATTERED NATURE OF THE CONVECTION...NOT ENOUGH CONFIDENCE TO
MENTION THUNDER IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH
FRIDAY. LATE NIGHT/EARLY MORNING FOG/STRATUS ALSO POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ030-
035>038-041.
GA...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ063>065-
077.
&&
$$
000
FXUS62 KCHS 220835
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
435 AM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD FRONT
WILL MOVE ACROSS THE AREA THURSDAY NIGHT WITH HIGH PRESSURE THEN
BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SHORTWAVE TROUGHING AT UPPER LEVELS TO PERSIST TODAY WHILE
ATLANTIC HIGH PRESSURE EXTENDS WEST INTO THE SOUTHEAST STATES AT
THE SURFACE. THE IN-SITU AIRMASS REMAINS QUITE MOIST WITH PW
VALUES HOVERING AT OR ABOVE 1.60 INCHES. THROUGH DAYBREAK A FEW
SHOWERS ARE POSSIBLE OVER THE COASTAL WATERS AND IMMEDIATE SC
COAST MAINLY NORTHEAST OF CHARLESTON IN SOME WEAK MOISTURE
CONVERGENCE. AFTER SUNRISE...THE DEEP-LAYERED SOUTHEAST FLOW WILL
ALLOW THE SEABREEZE TO DEVELOP FAIRLY EARLY. WITH TEMPS PUSHING
INTO THE MIDDLE TO UPPER 80S...MODERATE INSTABILITY WILL DEVELOP
YET AGAIN. SHOWERS AND TSTMS WILL INCREASE IN COVERAGE FROM LATE
MORNING INTO THE AFTERNOON WITH THE ACTIVITY LIKELY SHIFTING
GRADUALLY INLAND. CONVECTIVE PARAMETERS ARE NOT TERRIBLY
IMPRESSIVE BUT AN ISOLATED SEVERE STORM OR TWO CANNOT BE RULED
OUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
DIURNAL CONVECTION WILL TAPER OFF EARLY THIS EVENING OVER LAND BUT
ISOLATED SHOWERS OR STORMS WILL REMAIN POSSIBLE OVER THE COASTAL
WATERS OVERNIGHT. SOME FOG IS POSSIBLE LATE TONIGHT...ESPECIALLY
IN AREAS WHERE RAIN OCCURS TODAY.
THURSDAY...ATLANTIC HIGH PRESSURE WILL PREVAIL WHILE WEAK TROUGHING
PERSISTS INLAND. A SHORTWAVE EMBEDDED WITHIN BROAD UPPER LEVEL
TROUGHING WILL CROSS THE REGION AND PUSH THE DEEP LAYERED MOISTURE
OFFSHORE AS THE DAY PROGRESSES. THERE IS THE POTENTIAL FOR ISOLATED
CONVECTION ACROSS THE AREA IN THE MORNING AHEAD OF THE SHORT
WAVE...WITH THE COVERAGE INCREASING TO SCATTERED IN THE AFTERNOON
ACROSS MUCH OF SOUTHEAST SOUTH CAROLINA WHERE PRECIPITABLE WATER
VALUES AND LOW LEVEL CONVERGENCE WILL BE MAXIMIZED. A
WESTERLY/DOWNSLOPE FLOW ALOFT WILL PUSH TEMPERATURES TO HIGHS IN THE
UPPER 80S TO AROUND 90 AWAY FROM THE IMMEDIATE COAST.
THURSDAY NIGHT...AN UPPER LEVEL TROUGH WILL DIG TOWARD THE
APPALACHIANS...PUSHING A COLD FRONT ACROSS THE AREA. OTHER THAN SOME
ISOLATED CONVECTION EARLY IN THE EVENING MAINLY ACROSS THE
CHARLESTON TRI-COUNTY AREA...THE FRONT SHOULD PASS THROUGH RELATIVE
RAIN-FREE DUE TO A LACK OF DEEP LAYERED MOISTURE. LOWS WILL BE IN
THE LOWER TO MID 60S.
FRIDAY...THE UPPER LEVEL TROUGH WILL MOVE OVER THE MID-ATLANTIC AS
SURFACE HIGH PRESSURE BEGINS TO BUILD IN FROM THE GREAT LAKES REGION
IN WAKE OF THE DEPARTING COLD FRONT. MUCH DRIER AIR WILL FILTER INTO
THE AREA WITH A STRONG NORTHWEST/DOWNSLOPE WIND COMPONENT. THERE
WILL BE CONSIDERABLE SUNSHINE ALONG WITH BREEZY CONDITIONS IN THE
AFTERNOON. THE DOWNSLOPE FLOW WILL NEGATE MUCH OF THE COLD AIR
ADVECTION...ALLOWING TEMPERATURES TO REACH HIGHS IN THE MID AND
UPPER 80S ACROSS THE AREA AWAY FROM THE IMMEDIATE COAST.
FRIDAY NIGHT...RADIATIONAL COOLING WILL BE LIMITED BY A COUPLED
NORTHERLY FLOW THROUGH MUCH OF THE NIGHT...BUT THE DRY AIRMASS AND
CLEAR SKIES SHOULD STILL ALLOW TEMPERATURES TO FALL INTO THE THE MID
AND UPPER 50S...WITH SOME LOWER 50S POSSIBLE WELL INLAND.
SATURDAY...AN EXTREMELY DRY AIRMASS WILL BE IN PLACE TO START THE
WEEKEND...WITH PRECIPITABLE WATER VALUES AS LOW AS .25 TO .50 INCHES
WHICH IS MORE THAN 2 STANDARD DEVIATIONS BELOW NORMAL FOR THIS TIME
OF YEAR. GIVEN THIS DRY AIRMASS...THERE WILL BE CONSIDERABLE
SUNSHINE BUT A NORTH-NORTHEAST FLOW WILL LIMIT HIGHS TO THE UPPER
70S TO LOWER 80S ACROSS SOUTHEAST SOUTH CAROLINA AND THE LOWER TO
MID 80S ACROSS SOUTHEAST GEORGIA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD OVERALL AGREEMENT THROUGH THE LONG
TERM PERIOD. THE MID AND UPPER LEVEL PATTERN WILL FEATURE A NEARLY
ZONAL FLOW OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT
WEEK...WITH A RIDGE THEN BUILDING TOWARD THE MIDDLE OF NEXT WEEK. AT
THE SURFACE...HIGH PRESSURE WILL PASS NORTH OF THE AREA LATE IN THE
WEEKEND...THEN SETTLE OVER THE WESTERN ATLANTIC THROUGH THE MIDDLE
OF NEXT WEEK.
RAIN-FREE CONDITIONS ARE EXPECTED TO PERSIST INTO EARLY NEXT
WEEK...THEN INCREASING MOISTURE COULD ALLOW FOR SOME MAINLY DIURNAL
ISOLATED CONVECTION ALONG AND AHEAD OF THE SEA BREEZE TUESDAY AND
WEDNESDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL SUNDAY...THEN
RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
BETTER CHANCES FOR VSBY/CEILING RESTRICTIONS AT BOTH TERMINALS DUE
TO SUBSTANTIAL RAINFALL ON TUESDAY. KSAV WILL LIKELY CONTINUE AT
LEAST MVFR CEILINGS WITH POSSIBLE BRIEF DROPS TO IFR BEFORE
DAYBREAK. WE STILL SHOW KCHS DROPPING TO MVFR CIG/VSBY PRIOR TO
DAYBREAK AS WELL. THE BEST CHANCE OF DENSE FOG OR THE LIKE WILL BE
INLAND FROM EITHER TERMINAL.
FOR THE REST OF TODAY THE MAIN ISSUE IS ANOTHER ROUND OF CONVECTION
DEVELOPING ALONG THE SEABREEZE. WE INCLUDED PROB30 SHRA AT BOTH
TERMINALS FOR THE AFTERNOON HOURS GIVEN PRETTY GOOD INDICATIONS
THAT A LINE OF SHOWERS/STORMS WILL ROLL THROUGH THE AIRPORTS.
EXTENDED AVIATION...ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH
THURSDAY. A COLD FRONT WILL MOVE ACROSS THE AREA THURSDAY NIGHT
WITH HIGH PRESSURE THEN BUILDING OVER THE REGION THROUGH EARLY
NEXT WEEK.
&&
.MARINE...
MARINE CONDITIONS LOOK PRETTY QUIET THROUGH TONIGHT AS THE AREA
REMAINS ON THE WESTERN PERIPHERY OF ATLANTIC HIGH PRESSURE. THE
SEABREEZE SHOULD DEVELOP LATE THIS MORNING BUT WIND SPEEDS AT THE
COAST ARE NOT EXPECTED TO BE TERRIBLY IMPRESSIVE.
THURSDAY THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES OFFSHORE EARLY
FRIDAY. A NORTHERLY SURGE IS EXPECTED TO DEVELOP IN WAKE OF THE
FRONT FRIDAY NIGHT INTO EARLY SATURDAY AND COULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS. CONDITIONS WILL THEN IMPROVE LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH WINDS/SEAS EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A COLD FRONT
WILL MOVE ACROSS THE AREA THURSDAY NIGHT WITH HIGH PRESSURE THEN
BUILDING OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JRL
SHORT TERM...JAQ
LONG TERM...JAQ
AVIATION...JAQ/JRL
MARINE...JAQ/JRL
TIDES/COASTAL FLOODING...JAQ
000
FXUS62 KFFC 220800
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
400 AM EDT WED MAY 22 2013
.SHORT TERM /TODAY THROUGH THURSDAY/...
UPPER TROUGH WILL MOVE THROUGH THE UPPER MISSISSIPPI VALLEY TODAY
INTO TONIGHT. AN ASSOCIATED SHORT WAVE TRAILING INTO THE SOUTHERN
STATES WILL HELP FOCUS SHOWERS AND THUNDERSTORMS ACROSS THE CWA
THROUGH TONIGHT. AREA OF THUNDERSTORMS CURRENTLY MOVING INTO ALABAMA
MAY REACH NORTHWEST GEORGIA BY SUNRISE IF THEY HOLD TOGETHER. THIS
COMBINED WITH VARIOUS OUTFLOW BOUNDARIES WILL MAKE TIMING OF
CONVECTION DIFFICULT. HOWEVER THE BEST CHANCES WOULD SEEM TO BE THIS
AFTERNOON AND EVENING WITH DIURNAL HEATING. HAVE CONTINUED WITH THE
SEVERE WORDING ACROSS PORTIONS OF NORTH THIS AFTERNOON. THIS FITS
WELL WITH THE SPC SLIGHT RISK AREA. DIMINISHING POPS OVERNIGHT AS
THE SHORT WAVE MOVES INTO THE CAROLINAS. SOME DRYING INDICATED FOR
THURSDAY BUT WITH APPROACHING UPPER TROUGH...HAVE LEFT LOW POPS IN
ACROSS THE CWA. BASED ON TUESDAYS TEMPERATURES...HAVE STAYED ON THE
WARM SIDE OF MAV/MET. HOWEVER WITH ADDITIONAL CLOUDS AND
PRECIPITATION EXPECTED FOR TODAY...TEMPERATURES MAY VARY MORE ACROSS
THE CWA.
41
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A WEAK COLD FRONT AND MAIN UPPER SUPPORT WILL BE EXITING THE AREA
THURSDAY NIGHT. IT IS UNCLEAR HOW MUCH CONVECTIVE ACTIVITY THERE
WILL BE WITH THE GFS AND NAM INDICATING LITTLE OR NO MEASURABLE
RAIN AMOUNTS. LOOKS LIKE NO MORE THAN A SLIGHT CHANCE OF SHOWERS OR
THUNDERSTORMS FOR THE FIRST PART OF THURSDAY NIGHT.
MUCH DRIER AIRMASS MOVES OVER THE AREA ON FRIDAY WITH DRY NW FLOW
ALOFT AND SURFACE HIGH PRESSURE BUILDING OVER THE OH/TN VALLEYS
DURING THE DAY. GRADIENT WINDS WILL INCREASE GETTING CLOSE TO WIND
ADVISORY CRITERIA(20 MPH SUSTAINED) FOR SOME AREAS. DRY CONDITIONS
CONTINUE SATURDAY AND MOSTLY SUNDAY. HOWEVER THE NW FLOW ALOFT N OF
THE AREA IS BECOMING MORE ACTIVE WITH PRECIP CHANCES AND WHILE THE
GFS IS DRY FOR OUR AREA ON SUNDAY...MOISTURE IS SKIRTING NE GA. THE
EUROPEAN MEANWHILE IS INDICATING LIGHT PRECIP AMOUNTS OVER FAR N AND
E GA ON SUNDAY. A SIMILAR PATTERN CONTINUES FOR MONDAY AND TUESDAY
AS WELL. HIGH PRESSURE ALOFT BUILDS FOR WEDNESDAY AND EVEN WILL
SOUTHERLY FLOW OVER THE AREA...HIGH PRESSURE ALOFT WILL KEEP ANY
PRECIP CHANCES TO A MINIMUM. FOR NOW WILL FAVOR THE DRIER GFS.
TEMPERATURES GENERALLY RUNNING WITHIN 5 DEGREES OF NORMAL THROUGH
THE PERIOD EXCEPT SATURDAY MORNING LOWS ARE RUNNING 10-15 DEGREES
BELOW NORMAL AND SUNDAY MORNING LOWS ARE RUNNING CLOSE TO 10
DEGREES BELOW NORMAL.
BDL
&&
.AVIATION...
06Z UPDATE...
SOME MID/HIGH CLOUDS LINGERING INTO THE MORNING HOURS. VISIBILITY
SHOULD REMAIN ABOVE 6SM...BUT MAY DROP TO MVFR MAINLY ATHENS AND
MACON. VFR DURING THE DAY TODAY EXCEPT IN SHOWERS AND THUNDERSTORMS.
THERE MAY BE CONVECTION AROUND THE FORECAST AREA MUCH OF THE DAY BUT
THE BEST CHANCE FOR THUNDER AT ANY OF THE TAF SITES APPEARS TO BE
18Z AND INTO THE EARLY EVENING. VARIABLE TO LIGHT SOUTHEAST WINDS
THIS MORNING BECOMING SOUTHWEST 10KT AFTER 14Z.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF CONVECTION.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 65 87 59 / 40 40 30 20
ATLANTA 86 66 85 60 / 50 40 30 20
BLAIRSVILLE 80 61 80 55 / 60 60 30 20
CARTERSVILLE 84 63 84 57 / 60 60 30 20
COLUMBUS 90 67 89 63 / 30 30 30 20
GAINESVILLE 85 65 83 57 / 50 50 30 20
MACON 90 65 89 61 / 30 30 30 10
ROME 84 63 85 57 / 60 60 30 20
PEACHTREE CITY 86 62 86 59 / 40 30 30 20
VIDALIA 88 67 89 67 / 30 30 30 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41
LONG TERM....BDL
AVIATION...41
000
FXUS62 KCAE 220720
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
320 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REST OF TONIGHT...CONTINUED HIGH LOW-LEVEL MOISTURE SHOULD SUPPORT
STRATUS AND AREAS OF FOG DURING THE EARLY MORNING HOURS. THE
CLOUDINESS SHOULD HELP HOLD UP TEMPERATURES. THE TEMPERATURE
FORECAST APPEARS ON TRACK WITH LOWS IN THE MIDDLE 60S.
TODAY...HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CONTINUE TO
CIRCULATE MOIST AIR INTO THE FORECAST AREA. THE NAM AND GFS
CONTINUE TO INDICATE A WEAK MID-LEVEL SHORTWAVE TROUGH LINGERING
OVER THE FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS MAINLY
DURING THE TIME OF MAXIMUM HEATING. USED AN AVERAGE OF THE GFS AND
NAM MOS POPS. PRECIPITABLE WATER NEAR 1.7 OF AN INCH AND SLOW
STORM MOVEMENT SUPPORTS HEAVY RAIN WILL SOME OF THE THUNDERSTORMS.
HEAVY PRECIPITATION LOADINGS AND POSSIBLY MODERATE INSTABILITY
WITH H5 TEMPERATURES AROUND -10 SUPPORT A POSSIBILITY OF DAMAGING
WIND. USED THE WARMER TEMPERATURE GUIDANCE FOR TODAY BASED ON
YESTERDAY/S VERIFICATION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A CONTINUED MOIST SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH
PLUS A PRE-FRONTAL TROUGH SUPPORT THUNDERSTORMS TONIGHT. COVERAGE
WILL LIKELY BE LIMITED BY DIURNAL COOLING AND PREVIOUS CONVECTION.
THE NAM AND GFS MOS ARE IN GOOD AGREEMENT WITH POPS 30 TO 40 PERCENT.
THE MODELS SHOW THE PRE-FRONTAL TROUGH LINGERING THURSDAY BUT
DEEPER MOISTURE APPEARS TO SHIFT EAST OF THE FORECAST AREA EARLY
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE NAM AND GFS MOS
INDICATE VERY LOW POPS...BUT MAINTAINED CHANCE POPS BECAUSE OF
CONVERGENCE ASSOCIATED WITH THE PRE-FRONTAL TROUGH THURSDAY AND
THE COLD FRONT THURSDAY EVENING. FURTHER DRYING SHOULD OCCUR
BEHIND THE FRONT BY LATE THURSDAY NIGHT. THE TEMPERATURE GUIDANCE
WAS CLOSE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
AND TUESDAY. THE GFS AND ECMWF MOS PLUS GFS ENSEMBLE MEAN SUPPORTS
VERY LOW POPS. EXPECT BELOW NORMAL TEMPERATURES DURING THE
WEEKEND AND NEAR NORMAL DURING THE REST OF THE MEDIUM RANGE
PERIOD.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
EXPECT SCATTERED TO BROKEN MID AND HIGH LEVEL CLOUDS SHOULD DIMINISH
DURING THE EARLY MORNING HOURS. WITH CLEARING SKIES EXPECT AREAS OF
FOG AND STRATUS TO DEVELOP WHERE MOST OF THE RAIN FELL YESTERDAY.
EXPECT PERIODS OF MVFR/IFR AT MOST OF THE TAF SITES UNTIL AROUND
13Z...WITH POSSIBLE LIFR AT AGS. STRATUS AND FOG EXPECTED TO BURN
OFF DURING THE EARLY TO MID MORNING. LOW LEVEL MOISTURE WILL REMAIN
HIGH. VFR CONDITIONS DURING THE LATE MORNING AND AFTERNOON WITH
SCATTERED THUNDERSTORMS DEVELOPING AFTER 18Z. GIVEN THE EXPECTED
SCATTERED NATURE OF THE CONVECTION...NOT ENOUGH CONFIDENCE TO
MENTION THUNDER IN THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH
FRIDAY. LATE NIGHT/EARLY MORNING FOG/STRATUS ALSO POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
77
000
FXUS62 KCHS 220614
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
214 AM EDT WED MAY 22 2013
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THURSDAY. A
COLD FRONT WILL MOVE THROUGH THE AREA ON FRIDAY WITH DRY HIGH
PRESSURE BUILDING IN NEXT WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE FORECAST AREA LIES UNDERNEATH A WELL-DEFINED MID LEVEL
IMPULSE ACROSS FLORIDA WITH STRUNG OUT VORTICITY STRETCHING NORTH
AND NE OVERHEAD TO OFF THE COAST OF NC AND SE VA. THIS FEATURE
WILL MOVE LITTLE THROUGH THE NIGHT. MEANWHILE...THE BERMUDA HIGH
WILL LIE ATOP THE REGION AS A SUBTLE TROUGH DEVELOPS OVER THE
NEARBY ATLANTIC LATE.
MUCH OF THE NIGHT WILL BE RAIN FREE...ALTHOUGH WITH THE SHORT WAVE
ALOFT AND SOME CONVERGENCE DOWNSTAIRS...GIVEN THAT PWATS ARE NEAR
2 STANDARD DEVIATIONS ABOVE NORMAL FOR LATE MAY...WE LOOK FOR AN
INCREASE IN CONVECTION AGAIN OVER THE ATLANTIC OVERNIGHT. WE/RE
ALREADY SEEING SIGNS OF THAT OUT NEAR THE GULF STREAM. WITHIN THE
SOUTHERLY SYNOPTIC FLOW WE ANTICIPATE SOME OF THIS ACTIVITY WILL
MOVE INTO CHARLESTON AND FAR SE BERKELEY COUNTY BY SUNRISE.
GIVEN THE COPIOUS AMOUNT OF RAINS FROM EARLIER TODAY...FOG WILL
BECOME PROBLEMATIC AGAIN OVERNIGHT AS THE MID/HIGH LEVEL
CONVECTIVE DEBRIS CLOUD COVER DIMINISHES. WE HAVE EXPANDED THE
PATCHY FOG A LITTLE FURTHER SE WITH THE LATE EVENING UPDATE...AND
INCLUDED AREAS OF FOG ALONG PARTS OF THE NW TIER WHERE SOME OF THE
BETTER RAINFALL OCCURRED. LOCALLY DENSE FOG IS CERTAINLY A CONCERN
AND WE WILL RE-EVALUATE AGAIN WITH FUTURE UPDATES.
CONDITIONS WILL BE STICKY AND BALMY TONIGHT...WITH MINIMUM TEMPS
NO LOWER THAN THE MID-UPPER 60S INLAND AND AROUND 70 NEAR THE SHORE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
A FAIRLY SIMILAR PATTERN WILL PERSIST WEDNESDAY AND THURSDAY WITH
BROAD UPPER TROUGHING INLAND AND HIGH PRESSURE OVER THE ATLANTIC.
THIS PATTERN WILL MAINTAIN DEEP MOISTURE OVER THE AREA WITH DECENT
RAIN CHANCES THROUGH THE PERIOD...MOSTLY CONFINED INLAND DURING THE
DAY AND OVER THE ATLANTIC AT NIGHT. THE RISK FOR SEVERE WEATHER
APPEARS LOW GIVEN THE LACK OF ORGANIZATION POTENTIAL...ALTHOUGH
HEAVY RAINFALL COULD RESULT IN LOCALIZED FLOODING. HIGH/LOW
TEMPERATURES WILL ULTIMATELY DEPEND ON CLOUD COVER/RAINFALL BUT
GENERALLY SHOULD BE CLOSE TO SLIGHTLY ABOVE NORMAL.
A COLD FRONT SHOULD PUSH THROUGH FRIDAY MORNING...ALTHOUGH THE
NORTHWEST DOWNSLOPE FLOW WILL HELP TO OFFSET THE COLD ADVECTION.
THIS SHOULD LEAD TO TEMPERATURES CLOSE TO NORMAL IN THE MID 80S. THE
BIGGER CHANGE WILL BE THE DRIER AIR WHICH WILL MAKE IT FEEL A LOT
MORE COMFORTABLE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THERE IS GOOD MODEL AGREEMENT THAT DRY CANADIAN HIGH PRESSURE WILL
EXPAND SOUTHEAST INTO THE FORECAST AREA OVER THE WEEKEND THEN SHIFT
OFFSHORE. DEWPOINTS LOOK TO DROP INTO THE LOWER 50S SATURDAY AND
SUNDAY...WHICH COMBINED WITH HIGHS IN THE LOWER 80S WILL RESULT IN
PLEASANT SPRING WEATHER. OVERNIGHT LOWS WILL PROBABLY DROP INTO THE
UPPER 50S IN SPOTS. LOW-LEVEL MOISTURE INCREASES EARLY NEXT WEEK AS
THE SURFACE HIGH SHIFTS OFFSHORE...BUT WE DID NOT SEE ANY STRONG
SYNOPTIC SCALE FEATURES TO WARRANT ADDING PRECIP.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
BETTER CHANCES FOR VSBY/CEILING RESTRICTIONS AT BOTH TERMINALS DUE
TO SUBSTANTIAL RAINFALL ON TUESDAY. KSAV WILL LIKELY CONTINUE AT
LEAST MVFR CEILINGS WITH POSSIBLE BRIEF DROPS TO IFR BEFORE
DAYBREAK. WE STILL SHOW KCHS DROPPING TO MVFR CIG/VSBY PRIOR TO
DAYBREAK AS WELL. THE BEST CHANCE OF DENSE FOG OR THE LIKE WILL BE
INLAND FROM EITHER TERMINAL.
FOR THE REST OF TODAY THE MAIN ISSUE IS ANOTHER ROUND OF CONVECTION
DEVELOPING ALONG THE SEABREEZE. WE INCLUDED PROB30 SHRA AT BOTH
TERMINALS FOR THE AFTERNOON HOURS GIVEN PRETTY GOOD INDICATIONS
THAT A LINE OF SHOWERS/STORMS WILL ROLL THROUGH THE AIRPORTS.
EXTENDED AVIATION...SPORADIC REDUCTIONS IN CEILINGS/VSBYS MAINLY IN
AFTERNOON/EVENING SHOWERS OR STORMS THROUGH THURSDAY.
&&
.MARINE...
TONIGHT...THE TYPICAL SUB-TROPICAL RIDGE OF HIGH PRESSURE WILL
CONTINUE TO STRETCH ACROSS THE COASTAL WATERS...GENERATING SE AND
SOUTH WINDS OF LESS THAN 10 OR 15 KT. SEAS WILL HOLD IN A FAIRLY
STEADY STATE AT 2-4 FT...MAINLY IN A SE SWELL. WHILE THE RISK IS NOT
PARTICULARLY HIGH...THERE IS NONETHELESS A CHANCE OF ISOLATED
STRONGER STORMS MOVING IN AFTER 06Z.
WEDNESDAY THROUGH SUNDAY...ATLANTIC HIGH PRESSURE WILL DOMINATE
WITH SOUTHERLY FLOW UNTIL A COLD FRONT PUSHES THROUGH FRIDAY. THE
MUCH COOLER AND DRIER AIR MASS BEHIND THE FRONT WILL MOVE IN AND
LEAD TO INCREASING WINDS AND BUILDING SEAS...POSSIBLY REACHING
ADVISORY LEVELS...AT LEAST ACROSS THE WATERS BEYOND 20 NM.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENING. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AS WELL AS MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE BUT MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...JRL
SHORT TERM...RJB
LONG TERM...JRL
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
000
FXUS62 KFFC 220540
AFDFFC
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
135 AM EDT WED MAY 22 2013
.UPDATE...
UPDATED TO INCLUDE SOME POPS THROUGH MIDNIGHT FOR WEST CENTRAL GA AS
WESTWARD MOVING OUTFLOW BOUNDARY LIKELY TO SPAWN A FEW MORE
THUNDERSTORMS. WATCHING CLOSELY STORMS ACROSS NORTH GA FOR
POSSIBLE LOCALIZED FF THREAT AS WELL. MOST STORMS HAVE BEEN
PRODUCING PEA TO NICKEL SIZED HAIL THIS EVE AND EXPECT TREND TO
CONTINUE THROUGH 4Z TO 5Z.
OTHER UPDATE WAS TO GRIDS WED AFTN AND EVE TO INCLUDE SMALL HAIL
AND GUSTY WINDS AS THERE APPEARS TO BE A MARGINAL SEVERE THREAT
DUE TO SLIGHTLY INCREASING DEEP LAYER SHEAR
PROFILES....PARTICULARLY ACROSS NW AND NE GA. WILL NEED TO MONITOR
FOR POTENTIALLY INCREASING SEVERE THREAT AFTER 3 PM WED.
&&
.PREV DISCUSSION... /ISSUED 805 PM EDT TUE MAY 21 2013/
PREV DISCUSSION... /ISSUED 314 PM EDT TUE MAY 21 2013/
SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
MODELS CONTINUE IN GOOD AGREEMENT THROUGH THE SHORT TERM. AIRMASS
SHOWERS/TSTORMS DEVELOPING ACROSS THE CWA...MAINLY ACROSS THE
EXTREME NORTH AND EASTERN PARTS OF THE CWA. THESE WILL DISSIPATE
SHORTLY AFTER SUNSET THIS EVENING. THERE IS A POSSIBILITY THAT THE
STORMS OVER NORTHWEST AL AND CENTRAL TN COULD MAKE IT TO EXTREME
NORTHWEST GA BEFORE DIMINISHING THIS EVENING. THE H5 RIDGE OVER THE
EASTERN U.S. WILL WEAKEN AS THE CENTRAL U.S. TROUGH MOVES INTO THE
MISSISSIPPI VALLEY. THIS WILL PUSH A COLD FRONT INTO THE TENNESSEE
VALLEY WEDNESDAY WHICH WILL BRING A BETTER CHANCE OF THUNDERSTORMS
TO THE CWA...MAINLY ACROSS NORTH GA. INSTABILITY INCREASES WEDNESDAY
ACROSS NORTH GA AND THIS COULD PRODUCE A FEW STRONG STORMS. GUIDANCE
TEMPS LOOK GOOD FOR TONIGHT...ALTHOUGH TRICKY FOR WEDNESDAY WITH
ADDITIONAL CLOUDS. WILL TREND TO THE COOLER SIDE OF GUIDANCE ACROSS
NORTH GA FOR HIGHS ON WEDNESDAY DUE TO INCREASED CLOUDS AND PRECIP.
17
LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
BY WEDNESDAY EVENING...BOTH THE GFS AND ECMWF INDICATE THAT THE
FRONT WILL BE WEAKENING SIGNIFICANTLY. GFS REMAINS AB IT ON THE
STRONG SIDE WITH A SLIGHTLY MORE EAST WITH THE GREAT LAKES SURFACE
LOW. BOTH ARE TRANSITIONING THE UPPER LOW TO MORE OF A SHARP OPEN
TROUGH PHASING WITH THE LONGWAVE TROUGH IN CANADA. WEAK SHORTWAVE
OFF THE SOUTH CAROLINA COAST WILL LIFT NORTHEAST AND BE ABSORBED
BY THE LONGWAVE TROUGH AS WELL. SPC CONTINUES THE AREA IN GENERAL
THUNDER FOR THURSDAY...WITH MUCAPE VALUES 500-1000 J/KG EARLY IN
THE DAY...DECREASING BY MID-MORNING...AND INCREASING AGAIN IN
EXTREME SOUTHERN ZONES JUST AHEAD OF THE FRONT AFTER 18Z TO OVER
1000 J/KG. WILL HAVE TO MONITOR THE AREA FOR THE POTENTIAL FOR
ISOLATED STRONG STORMS BUT NOTHING TO SIGNIFICANT.
COLD FRONT SHOULD BE PUSHED THROUGH THE AREA BY LATE THURSDAY...
AND HAVE DECREASED TEMPS NORTHWEST SOMEWHAT TO LINE UP WITH THAT
TIMING A LITTLE BETTER. SHOULD SEE A SIGNIFICANT DECREASE IN TEMPS
TOWARD THE END OF THE WEEK WITH SURFACE HIGH PRESSURE BUILDING IN
AND NORTHWEST FLOW ALOFT...CURRENT FORECAST HAS HIGHS ON FRIDAY
ABOUT 5 DEGREES COOLER THAN HIGHS ON THURSDAY EXCEPT IN CENTRAL
GEORGIA. SEE PREVIOUS LONG TERM DISCUSSION BELOW.
TDP
AVIATION...
06Z UPDATE...
SOME MID/HIGH CLOUDS LINGERING INTO THE MORNING HOURS. VISIBILITY
SHOULD REMAIN ABOVE 6SM...BUT MAY DROP TO MVFR MAINLY ATHENS AND
MACON. VFR DURING THE DAY TODAY EXCEPT IN SHOWERS AND THUNDERSTORMS.
THERE MAY BE CONVECTION AROUND THE FORECAST AREA MUCH OF THE DAY BUT
THE BEST CHANCE FOR THUNDER AT ANY OF THE TAF SITES APPEARS TO BE
18Z AND INTO THE EARLY EVENING. VARIABLE TO LIGHT SOUTHEAST WINDS
THIS MORNING BECOMING SOUTHWEST 10KT AFTER 14Z.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF CONVECTION.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 64 84 64 84 / 30 40 40 30
ATLANTA 67 83 66 82 / 20 40 40 30
BLAIRSVILLE 60 77 60 78 / 30 60 60 30
CARTERSVILLE 64 84 62 82 / 20 60 60 30
COLUMBUS 68 89 67 87 / 20 30 30 30
GAINESVILLE 65 83 64 81 / 20 50 50 30
MACON 63 87 65 86 / 20 30 30 30
ROME 64 84 61 83 / 30 60 60 30
PEACHTREE CITY 63 85 63 84 / 20 40 30 30
VIDALIA 68 89 69 88 / 40 30 30 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...30
LONG TERM....SNELSON
AVIATION...41
000
FXUS62 KCAE 220453
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1253 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
REST OF TONIGHT...CONTINUED HIGH LOW-LEVEL MOISTURE SHOULD SUPPORT
STRATUS AND AREAS OF FOG DURING THE EARLY MORNING HOURS. THE
CLOUDINESS SHOULD HELP HOLD UP TEMPERATURES. THE TEMPERATURE
FORECAST APPEARS ON TRACK WITH LOWS IN THE MIDDLE 60S.
TODAY...HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CONTINUE TO
CIRCULATE MOIST AIR INTO THE FORECAST AREA. THE NAM AND GFS
CONTINUE TO INDICATE A WEAK MID-LEVEL SHORTWAVE TROUGH LINGERING
OVER THE FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS MAINLY
DURING THE TIME OF MAXIMUM HEATING. USED AN AVERAGE OF THE GFS AND
NAM MOS POPS. PRECIPITABLE WATER NEAR 1.7 OF AN INCH AND SLOW
STORM MOVEMENT SUPPORTS HEAVY RAIN WILL SOME OF THE THUNDERSTORMS.
HEAVY PRECIPITATION LOADINGS AND POSSIBLY MODERATE INSTABILITY
WITH H5 TEMPERATURES AROUND -10 SUPPORT A POSSIBILITY OF DAMAGING
WIND. USED THE WARMER TEMPERATURE GUIDANCE FOR TODAY BASED ON
YESTERDAY/S VERIFICATION.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
A CONTINUED MOIST SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH
PLUS A PRE-FRONTAL TROUGH SUPPORT THUNDERSTORMS TONIGHT. COVERAGE
WILL LIKELY BE LIMITED BY DIURNAL COOLING AND PREVIOUS CONVECTION.
THE NAM AND GFS MOS ARE IN GOOD AGREEMENT WITH POPS 30 TO 40 PERCENT.
THE MODELS SHOW THE PRE-FRONTAL TROUGH LINGERING THURSDAY BUT
DEEPER MOISTURE APPEARS TO SHIFT EAST OF THE FORECAST AREA EARLY
AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE NAM AND GFS MOS
INDICATE VERY LOW POPS...BUT MAINTAINED CHANCE POPS BECAUSE OF
CONVERGENCE ASSOCIATED WITH THE PRE-FRONTAL TROUGH THURSDAY AND
THE COLD FRONT THURSDAY EVENING. FURTHER DRYING SHOULD OCCUR
BEHIND THE FRONT BY LATE THURSDAY NIGHT. THE TEMPERATURE GUIDANCE
WAS CLOSE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
AND TUESDAY. THE GFS AND ECMWF MOS PLUS GFS ENSEMBLE MEAN SUPPORTS
VERY LOW POPS. EXPECT BELOW NORMAL TEMPERATURES DURING THE
WEEKEND AND NEAR NORMAL DURING THE REST OF THE MEDIUM RANGE
PERIOD.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
EXPECT SCATTERED TO BROKEN MID AND HIGH LEVEL CLOUDS SHOULD DIMINISH
DURING THE EARLY MORNING HOURS. WITH CLEARING SKIES EXPECT AREAS OF
FOG AND STRATUS TO DEVELOP WHERE MOST OF THE RAIN FELL. WILL HAVE
FOG AND STRATUS IN ALL TAFS STARTING AROUND 09Z UNTIL 13Z...ALTHOUGH
LATEST OBS SUGGEST THAT IFR CONDITIONS MAY DEVELOP AT AGS SOONER
THAN 09Z. STRATUS AND FOG EXPECTED TO BURN OFF DURING THE EARLY TO
MID MORNING. LOW LEVEL MOISTURE WILL REMAIN HIGH. VFR CONDITIONS
DURING THE LATE MORNING AND AFTERNOON WITH SCATTERED THUNDERSTORMS
DEVELOPING AFTER 18Z.
EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH
FRIDAY. LATE NIGHT/EARLY MORNING FOG/STRATUS ALSO POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
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