000
FXUS62 KCHS 161141
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
741 AM EDT WED MAY 16 2012

.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL LINGER ACROSS THE REGION THROUGH
THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND NORTHWEST
LATE IN THE WEEK AND PERSIST INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
JUST AFTER DAYBREAK...DRY WEATHER ACROSS THE REGION BUT IN THE
CHARLESTON TRI-COUNTY AREA...MOIST CONVERGENCE AND 70 DEGREE DEW
POINTS ENOUGH TO POP A FEW SHOWERS TO THE E OF CHARLESTON.
OTHERWISE...NOTING FROM FIRST VISIBLE SATELLITE IMAGES...UNSTABLE
MID LAYERED CLOUDS IN THE CSRA REGION ABOVE A WEAK SURFACE LOW.
THE DEEP CONVECTION OVER THE GULF OF MEXICO HAD PROGRESSED A BIT
QUICKER NE THAN JUST ABOUT ALL MODEL EXPECTATIONS. THIS CONVECTION
MAINLY ASSOCIATED WITH FORCING FROM THE LEFT FRONT REGION OF THE
SUBTROPICAL JET.

OUR FORECAST AREA TODAY REMAINS IN DEEP LAYERED SW FLOW WITH MID
LEVEL FLOW PROGGED TO GRADUALLY WEAKEN DURING THE DAY AS THE UPPER
TROUGH AXIS NUDGES VERY SLOWLY E WITH TIME. THROUGH MID MORNING
WE WILL LIKELY BE STARTING OFF WITH MORE IN THE WAY OF CLOUDS IN
SOME AREAS. BY LATE MORNING...CLOUDS EXPECTED TO SCATTER OUT ENOUGH
TO ALLOW WARMING TEMPS TO AROUND 80 WITH AT LEAST SOME WEAK
CAPPING TO OCCUR. THE 00Z NAM APPEARED TO HAVE SOME CONVECTIVE
FEEDBACK ISSUES ACROSS THE CAROLINAS AND WE TURNED TO THE ARW/NMM
FOR CONVECTIVE TRENDS ON THIS PACKAGE.

THIS AFTERNOON...MODELS INDICATE ANOTHER ROUND OF DIURNAL CONVECTION
FIRING ON THE SEA BREEZE AND VARIOUS BOUNDARIES. MODELS HAVE SOME
GENERAL CONSENSUS THAT OUR SOUTH CAROLINA REGION WILL HAVE HIGHER
CHANCES TO SEE WIDESPREAD CONVECTIVE RAINS THAN INLAND SE GEORGIA
WHERE PWATS ARE A BIT LOWER AND DEW POINTS POSSIBLY MIXING OUT TO
THE LOWER 60S LATER TODAY. SEVERE WEATHER POTENTIAL HINGES ON
CONVECTIVE INITIALIZATION TIMING ACROSS THE REGION BUT THERE
APPEARS TO BE POTENTIAL FOR ISOLATED SEVERE STORMS ONCE AGAIN WITH
PULSE AND MULTICELL PHASES LIKELY. FORECAST HAIL REGION CAPES ARE
A BIT BELOW VALUES SEEN ON TUE BUT DCAPE PROGS LOOK DECENT UP TO
INITIALIZATION TIME. SINCE MODEL CONSENSUS INDICATES SIGNIFICANT
LOW LEVEL CONVERGENCE AND GOOD CONVECTIVE QPF IN SE SOUTH CAROLINA
AFTER MID AFTERNOON...WE BUMPED POPS TO 60 PERCENT INLAND FROM
U.S. 17 INLAND N OF SAVANNAH. NO CHANGES TO MAX TEMPS MAINLY MID
80S MOST AREAS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
UPPER TROFFINESS CONTINUES TO PRESS INTO THE SE STATES TONIGHT
WITH A NICE DEEP MOISTURE GRADIENT BISECTING GEORGIA AND THE
CAROLINAS. EVENING CONVECTION SHOULD WANE BUT WILL NEED TO WATCH
FOR COASTAL LOW LEVEL MOISTURE CONVERGENCE AND SOME MID LEVEL WEAK
SHORT WAVES TO KEEP SOME SHOWERS AND STORMS GOING LONGER OR JUST
REDEVELOPING AFTER MIDNIGHT N OF THE SAVANNAH RIVER. WE KEPT SOME
CHANCE POPS GOING WELL INTO THE NIGHT TO TREND N OF SAVANNAH.

THURSDAY AND THURSDAY NIGHT...THE LONG AWAITED UPPER TROF WILL
FINALLY BE POISED TO MOVE ACROSS THE REGION THROUGH THE OVERNIGHT.
AS IT DOES...A BACKDOOR COLD FRONT COLD FRONT WILL SINK SOUTHWARD
INTO THE REGION WITH A SURFACE RIDGE FIRMLY IN PLACE BY LATE
THURSDAY. WITH SHORTWAVE ENERGY MOVING THROUGH AND PLENTIFUL LOW
LEVEL CONVERGENCE ALONG THE BACKDOOR FRONT AND DIURNAL HEATING
SHOULD RESULT IN PRETTY GOOD COVERAGE OF SHOWERS AND STORMS. I HAVE
INCREASED POPS A BIT...FAVORING SE GA FOR THE BEST COVERAGE IN THE
AFTERNOON WHERE THE BEST HEATING WILL TAKE PLACE. WITH MODERATE
INSTABILITY AND 500 MB TEMPS FALLING TO AROUND -14 C...A FEW
STRONG/SEVERE STORMS WILL BE POSSIBLE. HIGHS ARE EXPECTED TO BE IN
THE LOW TO MID 80S WITH LOWS IN THE MID 60S.

FRIDAY THROUGH SATURDAY...UPPER RIDGING WILL BUILD INTO THE NORTH
WITH THE REMNANT UPPER TROF BECOMING CUT OFF OVER THE SOUTHEAST.
THIS FEATURE WILL MOVE VERY LITTLE INTO THE WEEKEND WITH SOME MODEL
SOLUTIONS DEPICTING IT AS A CLOSED LOW. AT THE SURFACE THE HIGH WILL
REMAIN TO THE NORTHEAST WITH NE FLOW AND RIDGING IN PLACE ACROSS THE
CAROLINAS AND INTO GA. MODEL GUIDANCE IS A BIT MIXED ON PRECIP
POTENTIAL...BUT FAVORING THE COASTAL WATERS AND ALONG THE COAST
WITHIN A POSSIBLE COASTAL TROF. OVERALL CONFIDENCE IN PRECIP
POTENTIAL FOR ANY ONE TIME PERIOD IS LOW...SO I HAVE KEPT POPS IN
THE SLIGHT CHANCE TO CHANCE RANGE FAVORING JUST OFFSHORE. EXPECT
HIGHS IN THE LOW 80S AND LOWS IN THE LOW 60S.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MODEL SOLUTIONS CONTINUE TO EVOLVE REGARDING THE LONG TERM
PERIOD...AND ESPECIALLY THE UPPER LOW EXPECTED TO SIT OVER THE
SOUTHEAST FOR THE FIRST FEW DAYS. GENERAL CONSENSUS IS FOR THE UPPER
LOW TO DRIFT AROUND THE SOUTHEASTERN CONUS SUNDAY INTO MONDAY. THEN
THE RIDGE TO THE NORTH MOVES OFFSHORE AS ANOTHER TROF APPROACHES
FROM THE WEST AND BEGINS TO ABSORB THE CLOSED LOW. THIS WILL KEEP
THE REGION IN AN AREA OF TROFFING INTO THE MIDDLE OF THE WEEK. THE
LOW LEVEL RIDGE ASSOCIATED WITH THE SURFACE HIGH TO THE NORTHEAST
WILL REMAIN IN PLACE ACROSS THE FORECAST AREA THROUGH MONDAY. THE
RIDGE AND THE HIGH WILL THEN WEAKEN ON TUESDAY...LEAVING BEHIND A
RATHER NEBULOUS SURFACE PATTERN INTO THE MIDDLE OF THE WEEK. IT
APPEARS ANY ATLANTIC SURFACE LOW THAT DEVELOPS WILL REMAIN WELL
OFFSHORE AND OVERALL RAIN CHANCES WILL FAVOR THE COASTAL WATERS AND
COASTAL REGIONS. I HAVE KEPT THE SLIGHT CHANCE TO CHANCE POP REGIME
IN THE FORECAST WITH TEMPS RUNNING CLOSE TO CLIMO.

&&

.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
TIMING/COVERAGE/INTENSITY OF MAINLY DIURNAL CONVECTION REMAINS
DIFFICULT TO PIN DOWN TODAY AS NUMEROUS COMPLEX SYNOPTIC FEATURES
AT PLAY. WE HAVE BOTH KSAV/KCHS WITH VCTS THIS AFTERNOON WITH CB
CLOUDS AS THE SEA BREEZE SHOULD BE ACTIVE LATER TODAY. TONIGHT...
TSTMS SHOULD DECREASE DURING THE EARLY EVENING HOURS THEN A SHIELD
OF MID/HIGH CLOUDS EXPECTED OVERNIGHT. THESE CLOUDS WILL LIKELY DIMINISH
THE RISK FOR FOG BUT A FEW LOWER CLOUDS NOT OUT OF THE QUESTION. AT
KCHS...THERE MAY BE VCSH/VCTS LATE TONIGHT BUT CONFIDENCE IN ANY
OCCURRENCE IS QUITE LOW AT THIS POINT. OVERALL A VFR FORECAST.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS
WILL BE POSSIBLE THURSDAY DUE TO DIURNAL SHRA/TSRA. VFR CONDITIONS
WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
THROUGH TONIGHT...A WEAK PRES GRADIENT IS FORECAST AND WINDS SHOULD
BE MAINLY S TO SW LESS THAN 15 KT AND SEAS 2-4 FT...HIGHEST BEYOND
20 NM OFF THE COAST. THERE ARE SLIGHT CHANCES FOR SHOWERS AND TSTMS
BUT THE STRONGEST STORMS SHOULD BE INLAND FROM THE ATLC WATERS.

THURSDAY THROUGH SUNDAY...A COLD FRONT WILL SINK SOUTHWARD ACROSS
THE LOCAL WATERS THURSDAY AND THURSDAY NIGHT WHICH WILL RESULT IN
THE LOW LEVEL FLOW BECOMING INCREASINGLY N/NE AS HIGH PRESSURE
BUILDS IN. THE SURFACE HIGH WILL REMAIN POSITIONED TO THE NORTH
THROUGH THE WEEKEND AND A PINCHED NE GRADIENT WILL SET UP. WINDS AND
SEAS WILL BE ON THE INCREASE WITHIN THE STRENGTHENING NE FLOW FRIDAY
THROUGH SUNDAY...WITH SCA CONDITIONS BECOMING INCREASINGLY LIKELY.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

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

000
FXUS62 KFFC 161140 AAA
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
740 AM EDT WED MAY 16 2012

.PREV DISCUSSION...

SHORT TERM /TODAY THROUGH THURSDAY/...
/ISSUED 505 AM EDT WED MAY 16 2012/
CWA IS STILL UNDER UPPER LEVEL TROUGHING WHILE A SLOW MOVING FRONT
IS STILL POSITIONED ACROSS THE SOUTHEAST PORTION OF THE CWA...JUST
WEST OF KEZM TO KAGS. SHOWERS AND THUNDERSTORMS HAVE LINGERED INTO
THE EARLY MORNING...BUT HAVE STARTED TO WEAKEN. NAM DRIFTS SFC FRONT
SLIGHTLY NORTHWARD TODAY WHILE THE GFS KEEPS IT NEARLY STATIONARY
AND DRIFTS IT SOUTHEAST TONIGHT. LEANED TOWARD THE GFS ON THE
POSITION OF THE FRONT. FOCUS FOR BEST CONVECTION WILL REMAIN ACROSS
THE SOUTHEAST PORTION OF THE CWA...NEAR THE FRONT. IN
ADDITION...SLOW MOVING TROUGH AXIS WILL SLIDE INTO NORTHWEST GEORGIA
TODAY AND PROVIDE ADDITIONAL SUPPORT FOR CONVECTION. APPEARS TO BE
ANOTHER DAY OF ISOLATED TO SCATTERED SUMMERLIKE SHOWERS AND
THUNDERSTORMS WITH NAM AND GFS MUCAPE VALUES EXCEEDING 1500 J/KG AND
NEAR ZERO SHEAR. BEST INSTABILITY WILL BE ACROSS THE SOUTHEAST
PORTION OF THE CWA...CLOSER TO THE FRONT AND THIS WILL BE THE AREA
WITH THE BEST CHANCE FOR STRONGER STORMS.

BY THURSDAY...THE SFC FRONT WILL MOVE OUT OF THE CWA AND HIGH
PRESSURE WILL BUILD INTO THE NORTHEAST WITH THE BEGINNING OF RIDGING
DOWN THE APPALACHIANS. UPPER LEVEL TROUGH AXIS WILL STILL REMAIN
ACROSS THE CWA...BUT SHIFT TOWARD THE EASTERN SIDE. THIS WILL ONCE
AGAIN ALLOW FOR SUMMERLIKE CONVECTION.

THINK THE MAV IS A LITTLE TOO WARM TODAY SO LEANED TOWARD A MAV/MET
BLEND WITH SOME MINOR ADJUSTMENTS. MAV DEW POINTS ALSO APPEARED TO
BE TOO LOW THIS AFTERNOON AND TOMORROW AFTERNOON SO AGAIN LEANED
TOWARD A BLEND WHICH SEEMED MORE REASONABLE.

11

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
/ISSUED 505 AM EDT WED MAY 16 2012/
EXTENDED PROGS SIMILAR WITH THE AXIS OF THE UPPER TROF LINGERING
OVER THE EAST SIDE OF THE STATE THURSDAY NIGHT...BUT APPEARS TO
SHIFT OUT OF THE AREA FRIDAY AS UPPER RIDGING STRENGTHENS TO OUR
WEST AND NORTHWEST. MODELS CONTINUE TO SHOW SURFACE HIGH PRESSURE
WEDGING DOWN THE APPALACHIANS FRIDAY AND REMAINING OVER THE AREA
THROUGH THE WEEKEND. MODELS HINTING AT THE HIGH WEAKENING AND
BEGINNING TO SHIFT OFF THE MID ATLANTIC COAST MONDAY-TUESDAY TIME
FRAME AS A COLD FRONT MOVES INTO THE LOWER MISSISSIPPI RIVER
VALLEY. HAVE CONTINUED SLIGHT CHANCE POPS EXTREME NORTH AND
EXTREME SOUTHEAST COUNTIES THURSDAY NIGHT/FRIDAY WITH UPPER TROF
STILL HAVING SOME INFLUENCE. SLIGHT CHANCE POPS MAINLY SOUTHEAST
COUNTIES SATURDAY INTO SUNDAY WITH MODELS SHOWING A WEAK UPPER LOW
MEANDERING NEAR THE FLORIDA PANHANDLE. LOW POPS MUCH OF THE AREA
MONDAY AND TUESDAY WITH THE FRONTAL BOUNDARY APPROACHING.

49

&&

.AVIATION...
12Z UPDATE...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. VSBYS HAVE
DECREASED AT AHN AND MCN TO MVFR AND LOW VFR RESPECTIVELY...BUT
DO NOT THINK THESE CONDITIONS WILL LAST PAST 13Z. EXPECT CU
DEVELOPMENT LATE THIS MORNING AND THEN JUST HIGH CLOUDS OVERNIGHT
AGAIN. WINDS WILL REMAIN NORTHWEST TODAY AND BECOME NORTHEAST
OVERNIGHT TONIGHT.

//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS EXCEPT LOW CONFIDENCE ON
OCCURRENCE OF FEW030 THIS MORNING.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          84  61  85  62 /  30  30  20  10
ATLANTA         83  63  84  63 /  20  20  20   5
BLAIRSVILLE     79  55  78  56 /  20  20  30  20
CARTERSVILLE    84  54  86  57 /  10  10  20  10
COLUMBUS        87  64  86  62 /  20  20  20  10
GAINESVILLE     82  61  83  61 /  20  20  20  10
MACON           86  60  86  62 /  30  30  30  10
ROME            84  57  86  59 /  10  10  20  10
PEACHTREE CITY  83  57  84  58 /  20  20  20  10
VIDALIA         87  66  85  65 /  30  30  30  20

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS62 KCAE 161130
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
730 AM EDT WED MAY 16 2012

.SYNOPSIS...
A BROAD AND SLOW MOVING TROUGH OF LOW PRESSURE WILL MOVE EAST
ACROSS THE AREA TODAY AND THURSDAY...KEEPING RAIN CHANCES IN THE
FORECAST. HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTH
BY FRIDAY AND REMAIN IN PLACE THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
CONVERGENCE AND HIGH LOW-LEVEL MOISTURE ASSOCIATED WITH THE FRONT
PLUS COLD TEMPERATURES ALOFT SHOULD SUPPORT THUNDERSTORMS AGAIN
TODAY...MAINLY DURING THE TIME OF MAXIMUM HEATING. DEEPER MOISTURE
SUPPORTS SOMEWHAT HIGHER POPS IN THE EAST PART OF THE FORECAST
AREA. LEANED TOWARD THE NAM MOS POPS WHICH HAVE VERIFIED BETTER
LATELY AND APPEAR MORE REASONABLE BECAUSE OF THE SUPPORT. THE NAM
INDICATES MODERATE INSTABILITY AND EXPECT A FEW OF THE
THUNDERSTORMS WILL CONTAIN DAMAGING WIND AND HAIL. THE WARMER MAV
MOS TEMPERATURES MAY BE BETTER TODAY BASED ON YESTERDAY/S
VERIFICATION.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
LINGERING UPPER TROUGH AND SURFACE BOUNDARY IN THE AREA WILL
FINALLY SLOWLY PUSH EAST THROUGH THE FORECAST AREA OVERNIGHT.
EXPECT ISOLATED TO SCATTERED CONVECTION TO START THE PERIOD
SUPPORTED BY RELATIVELY HIGH MID LEVEL LAPSE RATES AND
PRECIPITABLE WATER VALUES ABOVE 1.25 INCHES THIS EVENING. WILL
CONTINUE TO CARRY CHANCE POPS THROUGH THE EVENING HOURS AND
DIMINISH POPS AFTER MIDNIGHT. OVERNIGHT LOWS WILL BE SIMILAR TO
PREVIOUS NIGHTS...IN THE LOWER 60S.

BY THURSDAY MORNING...THE SURFACE BOUNDARY SHOULD BE SITUATED OVER
THE EASTERN MIDLANDS OR JUST EAST OF THE FORECAST AREA WITH
NORTHEASTERLY FLOW AT THE SURFACE UP TO AROUND 10000 FT. THE UPPER
TROUGH AXIS WILL BE ALIGNED OVER THE FORECAST AREA WITH COOLING
500MB TEMPERATURES. THE MID LEVEL COOLING COMBINED WITH DAYTIME
HEATING SHOULD LEAD TO A MODERATELY UNSTABLE AIRMASS ACROSS THE
EASTERN MIDLANDS...IN THE VICINITY OF THE SURFACE FRONT...AND WILL
NEED TO HOLD ON TO CHANCE POPS ACROSS THE FORECAST AREA WITH THE
HIGHEST POPS EAST. ISOLATED SEVERE CONVECTION REMAINS A
POSSIBILITY BUT COVERAGE SHOULD NOT BE AS EXTENSIVE AS IT HAS BEEN
EARLIER IN THE WEEK. MAX TEMPERATURES WILL BE NEAR NORMAL IN THE
LOWER TO MID 80S.

HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA THURSDAY NIGHT AS
EASTERLY FLOW DEEPENS ACROSS THE REGION. PRECIPITABLE WATER VALUES
DECREASE TO BELOW AN INCH BY FRIDAY MORNING AND REMAIN LOW THROUGH
FRIDAY NIGHT. COOL NORTHEASTERLY FLOW WILL PROVIDE A MORE STABLE
ATMOSPHERE ON FRIDAY AND WITH MUCH LESS MOISTURE AVAILABLE DO NOT
ANTICIPATE ANY PRECIPITATION FRIDAY AND FRIDAY NIGHT AS THE FRONTAL
BOUNDARY AND UPPER TROUGH AXIS REMAINS TO THE EAST. TEMPERATURES
ON FRIDAY WILL BE SLIGHTLY COOLER WITH HIGHS AROUND 80 TO THE
LOWER 80S AND LOWS FRIDAY NIGHT WILL FALL INTO THE 50S ACROSS THE
AREA.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
LITTLE CHANGE DURING THIS PERIOD.

MEDIUM RANGE MODELS ARE TRENDING MORE TOWARDS A BROAD UPPER TROUGH
DEVELOPING OVER THE SOUTHEASTERN STATES...BENEATH AN UPPER RIDGE
LOCATED OVER THE OHIO VALLEY OVER THE WEEKEND. PERSISTENT DEEP
EASTERLY FLOW OFF THE ATLANTIC WILL BRING MOISTURE BACK INTO THE
FORECAST AREA BY SUNDAY AS PRECIPITABLE WATER VALUES INCREASE TO
OVER 1.25 INCHES. WILL CONTINUE WITH A DRY FORECAST ON SATURDAY
BUT RAIN CHANCES RETURN TO THE FORECAST SUNDAY THROUGH EARLY NEXT
WEEK. TEMPERATURES DURING THIS PERIOD SHOULD BE NEAR NORMAL. IT IS
WORTH NOTING THAT THIS IS A LOW CONFIDENCE FORECAST DUE TO THE
LACK OF RUN TO RUN CONSISTENCY AMONG THE MODELS AND RELATIVELY
WEAK FLOW PATTERN...LEADING TO A FORECAST DOMINATED BY SMALLER
SCALE FEATURES WHICH ARE TOUGH TO PINPOINT IN THE EXTENDED
PERIODS.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
MAINLY MVFR VSBYS IN EARLY MORNING FOG...DISSIPATING BY MID
MORNING. MID TO HIGH LEVEL CLOUDINESS IN PLACE. WILL EXPECT
DIURNAL CU...AND SCATTERED SHOWERS AND THUNDERSTORMS THIS
AFTERNOON. DID NOT INCLUDE THUNDERSTORMS IN THE TERMINAL
FORECASTS BECAUSE OF COVERAGE AND TIMING UNCERTAINTY. MVFR OR IFR
STRATUS AND FOG LATE TONIGHT.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR IFR STRATUS AND FOG
MAY OCCUR DURING THE EARLY MORNING HOURS THURSDAY AND FRIDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KFFC 160905
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
505 AM EDT WED MAY 16 2012

.SHORT TERM /TODAY THROUGH THURSDAY/...
CWA IS STILL UNDER UPPER LEVEL TROUGHING WHILE A SLOW MOVING FRONT
IS STILL POSITIONED ACROSS THE SOUTHEAST PORTION OF THE CWA...JUST
WEST OF KEZM TO KAGS. SHOWERS AND THUNDERSTORMS HAVE LINGERED INTO
THE EARLY MORNING...BUT HAVE STARTED TO WEAKEN. NAM DRIFTS SFC FRONT
SLIGHTLY NORTHWARD TODAY WHILE THE GFS KEEPS IT NEARLY STATIONARY
AND DRIFTS IT SOUTHEAST TONIGHT. LEANED TOWARD THE GFS ON THE
POSITION OF THE FRONT. FOCUS FOR BEST CONVECTION WILL REMAIN ACROSS
THE SOUTHEAST PORTION OF THE CWA...NEAR THE FRONT. IN
ADDITION...SLOW MOVING TROUGH AXIS WILL SLIDE INTO NORTHWEST GEORGIA
TODAY AND PROVIDE ADDITIONAL SUPPORT FOR CONVECTION. APPEARS TO BE
ANOTHER DAY OF ISOLATED TO SCATTERED SUMMERLIKE SHOWERS AND
THUNDERSTORMS WITH NAM AND GFS MUCAPE VALUES EXCEEDING 1500 J/KG AND
NEAR ZERO SHEAR. BEST INSTABILITY WILL BE ACROSS THE SOUTHEAST
PORTION OF THE CWA...CLOSER TO THE FRONT AND THIS WILL BE THE AREA
WITH THE BEST CHANCE FOR STRONGER STORMS.

BY THURSDAY...THE SFC FRONT WILL MOVE OUT OF THE CWA AND HIGH
PRESSURE WILL BUILD INTO THE NORTHEAST WITH THE BEGINNING OF RIDGING
DOWN THE APPALACHIANS. UPPER LEVEL TROUGH AXIS WILL STILL REMAIN
ACROSS THE CWA...BUT SHIFT TOWARD THE EASTERN SIDE. THIS WILL ONCE
AGAIN ALLOW FOR SUMMERLIKE CONVECTION.

THINK THE MAV IS A LITTLE TOO WARM TODAY SO LEANED TOWARD A MAV/MET
BLEND WITH SOME MINOR ADJUSTMENTS. MAV DEW POINTS ALSO APPEARED TO
BE TOO LOW THIS AFTERNOON AND TOMORROW AFTERNOON SO AGAIN LEANED
TOWARD A BLEND WHICH SEEMED MORE REASONABLE.

11

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
EXTENDED PROGS SIMILAR WITH THE AXIS OF THE UPPER TROF LINGERING
OVER THE EAST SIDE OF THE STATE THURSDAY NIGHT...BUT APPEARS TO
SHIFT OUT OF THE AREA FRIDAY AS UPPER RIDGING STRENGTHENS TO OUR
WEST AND NORTHWEST. MODELS CONTINUE TO SHOW SURFACE HIGH PRESSURE
WEDGING DOWN THE APPALACHIANS FRIDAY AND REMAINING OVER THE AREA
THROUGH THE WEEKEND. MODELS HINTING AT THE HIGH WEAKENING AND
BEGINNING TO SHIFT OFF THE MID ATLANTIC COAST MONDAY-TUESDAY TIME
FRAME AS A COLD FRONT MOVES INTO THE LOWER MISSISSIPPI RIVER
VALLEY. HAVE CONTINUED SLIGHT CHANCE POPS EXTREME NORTH AND
EXTREME SOUTHEAST COUNTIES THURSDAY NIGHT/FRIDAY WITH UPPER TROF
STILL HAVING SOME INFLUENCE. SLIGHT CHANCE POPS MAINLY SOUTHEAST
COUNTIES SATURDAY INTO SUNDAY WITH MODELS SHOWING A WEAK UPPER LOW
MEANDERING NEAR THE FLORIDA PANHANDLE. LOW POPS MUCH OF THE AREA
MONDAY AND TUESDAY WITH THE FRONTAL BOUNDARY APPROACHING.

49

&&

&&

.AVIATION...
06Z UPDATE...
VFR CONDITIONS ACROSS THE TAF SITES AND GENERALLY EXPECTED TO
CONTINUE THROUGH THE FORECAST PERIOD. THE EXCEPTION TO THIS MAY BE
SOME MVFR VSBYS AT THE USUAL FOG SITES...FTY...AHN AND MCN.
CONFIDENCE IS LOW ON JUST HOW LOW THESE SITES WILL GO. EXPECT CU
TO DEVELOP LATE THIS MORNING. ALTHOUGH THUNDERSTORM CHANCES AT
THE TAF SITES ARE LOW...DID INCLUDE PROB30 AT MCN AND AHN THAT
HAVE THE BEST CHANCES. WEST WINDS WILL BECOME MORE NW TODAY AT
ATL.

//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ON WINDS...CIGS AND VSBYS.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          84  61  85  62 /  30  30  20  10
ATLANTA         83  63  84  63 /  20  20  20   5
BLAIRSVILLE     79  55  78  56 /  20  20  30  20
CARTERSVILLE    84  54  86  57 /  10  10  20  10
COLUMBUS        87  64  86  62 /  20  20  20  10
GAINESVILLE     82  61  83  61 /  20  20  20  10
MACON           86  60  86  62 /  30  30  30  10
ROME            84  57  86  59 /  10  10  20  10
PEACHTREE CITY  83  57  84  58 /  20  20  20  10
VIDALIA         87  66  85  65 /  30  30  30  20

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS62 KCHS 160822
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
422 AM EDT WED MAY 16 2012

.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL LINGER ACROSS THE REGION THROUGH
THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND NORTHWEST
LATE IN THE WEEK AND PERSIST INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRE-DAWN...WE HAVE SEEN CONVECTIVE RAINS LINGER OVERNIGHT IN PARTS
OF SE GEORGIA OVERNIGHT IN A REGION OF DEEP MOIST CONVERGENCE AND
WEAK UPPER DIFLUENCE...BUT ONLY A FEW LIGHT SHOWERS REMAIN. DEBRIS
CLOUDS AND LIGHT BREEZES HAVE KEPT TEMPS ELEVATED IN QUITE A FEW
AREAS EARLY THIS MORNING.

OUR FORECAST AREA TODAY REMAINS IN DEEP LAYERED SW FLOW WITH MID
LEVEL FLOW PROGGED TO GRADUALLY WEAKEN DURING THE DAY AS THE UPPER
TROUGH AXIS NUDGES VERY SLOWLY E WITH TIME. THROUGH MID MORNING
WE WILL LIKELY BE STARTING OFF WITH MORE IN THE WAY OF CLOUDS IN
SOME AREAS. BY LATE MORNING...CLOUDS EXPECTED TO SCATTER OUT ENOUGH
TO ALLOW WARMING TEMPS TO AROUND 80 WITH AT LEAST SOME WEAK
CAPPING TO OCCUR. THE 00Z NAM APPEARED TO HAVE SOME CONVECTIVE
FEEDBACK ISSUES ACROSS THE CAROLINAS AND WE TURNED TO THE ARW/NMM
FOR CONVECTIVE TRENDS ON THIS PACKAGE.

THIS AFTERNOON...MODELS INDICATE ANOTHER ROUND OF DIURNAL CONVECTION
FIRING ON THE SEA BREEZE AND VARIOUS BOUNDARIES. MODELS HAVE SOME
GENERAL CONSENSUS THAT OUR SOUTH CAROLINA REGION WILL HAVE HIGHER
CHANCES TO SEE WIDESPREAD CONVECTIVE RAINS THAN INLAND SE GEORGIA
WHERE PWATS ARE A BIT LOWER AND DEW POINTS POSSIBLY MIXING OUT TO
THE LOWER 60S LATER TODAY. SEVERE WEATHER POTENTIAL HINGES ON
CONVECTIVE INITIALIZATION TIMING ACROSS THE REGION BUT THERE
APPEARS TO BE POTENTIAL FOR ISOLATED SEVERE STORMS ONCE AGAIN WITH
PULSE AND MULTICELL PHASES LIKELY. FORECAST HAIL REGION CAPES ARE
A BIT BELOW VALUES SEEN ON TUE BUT DCAPE PROGS LOOK DECENT UP TO
INITIALIZATION TIME. SINCE MODEL CONSENSUS INDICATES SIGNIFICANT
LOW LEVEL CONVERGENCE AND GOOD CONVECTIVE QPF IN SE SOUTH CAROLINA
AFTER MID AFTERNOON...WE BUMPED POPS TO 60 PERCENT INLAND FROM
U.S. 17 INLAND N OF SAVANNAH. NO CHANGES TO MAX TEMPS MAINLY MID
80S MOST AREAS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
UPPER TROFFINESS CONTINUES TO PRESS INTO THE SE STATES TONIGHT
WITH A NICE DEEP MOISTURE GRADIENT BISECTING GEORGIA AND THE
CAROLINAS. EVENING CONVECTION SHOULD WANE BUT WILL NEED TO WATCH
FOR COASTAL LOW LEVEL MOISTURE CONVERGENCE AND SOME MID LEVEL WEAK
SHORT WAVES TO KEEP SOME SHOWERS AND STORMS GOING LONGER OR JUST
REDEVELOPING AFTER MIDNIGHT N OF THE SAVANNAH RIVER. WE KEPT SOME
CHANCE POPS GOING WELL INTO THE NIGHT TO TREND N OF SAVANNAH.

THURSDAY AND THURSDAY NIGHT...THE LONG AWAITED UPPER TROF WILL
FINALLY BE POISED TO MOVE ACROSS THE REGION THROUGH THE OVERNIGHT.
AS IT DOES...A BACKDOOR COLD FRONT COLD FRONT WILL SINK SOUTHWARD
INTO THE REGION WITH A SURFACE RIDGE FIRMLY IN PLACE BY LATE
THURSDAY. WITH SHORTWAVE ENERGY MOVING THROUGH AND PLENTIFUL LOW
LEVEL CONVERGENCE ALONG THE BACKDOOR FRONT AND DIURNAL HEATING
SHOULD RESULT IN PRETTY GOOD COVERAGE OF SHOWERS AND STORMS. I HAVE
INCREASED POPS A BIT...FAVORING SE GA FOR THE BEST COVERAGE IN THE
AFTERNOON WHERE THE BEST HEATING WILL TAKE PLACE. WITH MODERATE
INSTABILITY AND 500 MB TEMPS FALLING TO AROUND -14 C...A FEW
STRONG/SEVERE STORMS WILL BE POSSIBLE. HIGHS ARE EXPECTED TO BE IN
THE LOW TO MID 80S WITH LOWS IN THE MID 60S.

FRIDAY THROUGH SATURDAY...UPPER RIDGING WILL BUILD INTO THE NORTH
WITH THE REMNANT UPPER TROF BECOMING CUT OFF OVER THE SOUTHEAST.
THIS FEATURE WILL MOVE VERY LITTLE INTO THE WEEKEND WITH SOME MODEL
SOLUTIONS DEPICTING IT AS A CLOSED LOW. AT THE SURFACE THE HIGH WILL
REMAIN TO THE NORTHEAST WITH NE FLOW AND RIDGING IN PLACE ACROSS THE
CAROLINAS AND INTO GA. MODEL GUIDANCE IS A BIT MIXED ON PRECIP
POTENTIAL...BUT FAVORING THE COASTAL WATERS AND ALONG THE COAST
WITHIN A POSSIBLE COASTAL TROF. OVERALL CONFIDENCE IN PRECIP
POTENTIAL FOR ANY ONE TIME PERIOD IS LOW...SO I HAVE KEPT POPS IN
THE SLIGHT CHANCE TO CHANCE RANGE FAVORING JUST OFFSHORE. EXPECT
HIGHS IN THE LOW 80S AND LOWS IN THE LOW 60S.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MODEL SOLUTIONS CONTINUE TO EVOLVE REGARDING THE LONG TERM
PERIOD...AND ESPECIALLY THE UPPER LOW EXPECTED TO SIT OVER THE
SOUTHEAST FOR THE FIRST FEW DAYS. GENERAL CONSENSUS IS FOR THE UPPER
LOW TO DRIFT AROUND THE SOUTHEASTERN CONUS SUNDAY INTO MONDAY. THEN
THE RIDGE TO THE NORTH MOVES OFFSHORE AS ANOTHER TROF APPROACHES
FROM THE WEST AND BEGINS TO ABSORB THE CLOSED LOW. THIS WILL KEEP
THE REGION IN AN AREA OF TROFFING INTO THE MIDDLE OF THE WEEK. THE
LOW LEVEL RIDGE ASSOCIATED WITH THE SURFACE HIGH TO THE NORTHEAST
WILL REMAIN IN PLACE ACROSS THE FORECAST AREA THROUGH MONDAY. THE
RIDGE AND THE HIGH WILL THEN WEAKEN ON TUESDAY...LEAVING BEHIND A
RATHER NEBULOUS SURFACE PATTERN INTO THE MIDDLE OF THE WEEK. IT
APPEARS ANY ATLANTIC SURFACE LOW THAT DEVELOPS WILL REMAIN WELL
OFFSHORE AND OVERALL RAIN CHANCES WILL FAVOR THE COASTAL WATERS AND
COASTAL REGIONS. I HAVE KEPT THE SLIGHT CHANCE TO CHANCE POP REGIME
IN THE FORECAST WITH TEMPS RUNNING CLOSE TO CLIMO.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
THROUGH DAYBREAK...CONCERN FOR AREAS OF MVFR/IFR CIGS WITH
INDICATIONS THAT KSAV HAS A BETTER POTENTIAL SINCE LOW-END MVFR
CIGS ALREADY NOTED ON 05Z OBSERVATIONS. CONVECTIVE RAINS SW OF
KSAV SHOULD REMAIN JUST SW TO W OF THE TERMINAL BUT CONFIDENCE ON
HOW MESOSCALE TRENDS PLAY OUT OVERNIGHT IS NOT GREAT...ALTHOUGH
PCPN COVERAGE SHOULD DIMINISH TOWARD DAYBREAK. WE HAVE MAINTAINED
TRENDS FROM THE 00Z TAF CYCLE FOR THE MOST PART.

ANOTHER ROUND OF DIURNAL CONVECTION SEEMS A GOOD BET THIS AFTERNOON
AND POSSIBLY INTO THE EVENING ALONG PARTS OF THE COASTAL CORRIDOR.
WE HAVE MAINTAINED PROBS FOR BEST CHANCE TIMING IN THE MID/LATE
DAY HOURS.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THURSDAY DUE TO DIURNAL SHRA/TSRA. VFR CONDITIONS WITH GUSTY
WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
THROUGH TONIGHT...A WEAK PRES GRADIENT IS FORECAST AND WINDS SHOULD
BE MAINLY S TO SW LESS THAN 15 KT AND SEAS 2-4 FT...HIGHEST BEYOND
20 NM OFF THE COAST. THERE ARE SLIGHT CHANCES FOR SHOWERS AND TSTMS
BUT THE STRONGEST STORMS SHOULD BE INLAND FROM THE ATLC WATERS.

THURSDAY THROUGH SUNDAY...A COLD FRONT WILL SINK SOUTHWARD ACROSS
THE LOCAL WATERS THURSDAY AND THURSDAY NIGHT WHICH WILL RESULT IN
THE LOW LEVEL FLOW BECOMING INCREASINGLY N/NE AS HIGH PRESSURE
BUILDS IN. THE SURFACE HIGH WILL REMAIN POSITIONED TO THE NORTH
THROUGH THE WEEKEND AND A PINCHED NE GRADIENT WILL SET UP. WINDS AND
SEAS WILL BE ON THE INCREASE WITHIN THE STRENGTHENING NE FLOW FRIDAY
THROUGH SUNDAY...WITH SCA CONDITIONS BECOMING INCREASINGLY LIKELY.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

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

000
FXUS62 KCAE 160747
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
347 AM EDT WED MAY 16 2012

.SYNOPSIS...

A BROAD AND SLOW MOVING TROUGH OF LOW PRESSURE WILL MOVE EAST
ACROSS THE AREA TODAY AND THURSDAY...KEEPING RAIN CHANCES IN THE
FORECAST. HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTH
BY FRIDAY AND REMAIN IN PLACE THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...

CONVERGENCE AND HIGH LOW-LEVEL MOISTURE ASSOCIATED WITH THE FRONT
PLUS COLD TEMPERATURES ALOFT SHOULD SUPPORT THUNDERSTORMS AGAIN
TODAY...MAINLY DURING THE TIME OF MAXIMUM HEATING. DEEPER MOISTURE
SUPPORTS SOMEWHAT HIGHER POPS IN THE EAST PART OF THE FORECAST
AREA. LEANED TOWARD THE NAM MOS POPS WHICH HAVE VERIFIED BETTER
LATELY AND APPEAR MORE REASONABLE BECAUSE OF THE SUPPORT. THE NAM
INDICATES MODERATE INSTABILITY AND EXPECT A FEW OF THE
THUNDERSTORMS WILL CONTAIN DAMAGING WIND AND HAIL. THE WARMER MAV
MOS TEMPERATURES MAY BE BETTER TODAY BASED ON YESTERDAY/S
VERIFICATION.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...

LINGERING UPPER TROUGH AND SURFACE BOUNDARY IN THE AREA WILL
FINALLY SLOWLY PUSH EAST THROUGH THE FORECAST AREA OVERNIGHT.
EXPECT ISOLATED TO SCATTERED CONVECTION TO START THE PERIOD
SUPPORTED BY RELATIVELY HIGH MID LEVEL LAPSE RATES AND
PRECIPITABLE WATER VALUES ABOVE 1.25 INCHES THIS EVENING. WILL
CONTINUE TO CARRY CHANCE POPS THROUGH THE EVENING HOURS AND
DIMINISH POPS AFTER MIDNIGHT. OVERNIGHT LOWS WILL BE SIMILAR TO
PREVIOUS NIGHTS...IN THE LOWER 60S.

BY THURSDAY MORNING...THE SURFACE BOUNDARY SHOULD BE SITUATED OVER
THE EASTERN MIDLANDS OR JUST EAST OF THE FORECAST AREA WITH
NORTHEASTERLY FLOW AT THE SURFACE UP TO AROUND 10000 FT. THE UPPER
TROUGH AXIS WILL BE ALIGNED OVER THE FORECAST AREA WITH COOLING
500MB TEMPERATURES. THE MID LEVEL COOLING COMBINED WITH DAYTIME
HEATING SHOULD LEAD TO A MODERATELY UNSTABLE AIRMASS ACROSS THE
EASTERN MIDLANDS...IN THE VICINITY OF THE SURFACE FRONT...AND WILL
NEED TO HOLD ON TO CHANCE POPS ACROSS THE FORECAST AREA WITH THE
HIGHEST POPS EAST. ISOLATED SEVERE CONVECTION REMAINS A
POSSIBILITY BUT COVERAGE SHOULD NOT BE AS EXTENSIVE AS IT HAS BEEN
EARLIER IN THE WEEK. MAX TEMPERATURES WILL BE NEAR NORMAL IN THE
LOWER TO MID 80S.

HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA THURSDAY NIGHT AS
EASTERLY FLOW DEEPENS ACROSS THE REGION. PRECIPITABLE WATER VALUES
DECREASE TO BELOW AN INCH BY FRIDAY MORNING AND REMAIN LOW THROUGH
FRIDAY NIGHT. COOL NORTHEASTERLY FLOW WILL PROVIDE A MORE STABLE
ATMOSPHERE ON FRIDAY AND WITH MUCH LESS MOISTURE AVAILABLE DO NOT
ANTICIPATE ANY PRECIPITATION FRIDAY AND FRIDAY NIGHT AS THE FRONTAL
BOUNDARY AND UPPER TROUGH AXIS REMAINS TO THE EAST. TEMPERATURES
ON FRIDAY WILL BE SLIGHTLY COOLER WITH HIGHS AROUND 80 TO THE
LOWER 80S AND LOWS FRIDAY NIGHT WILL FALL INTO THE 50S ACROSS THE
AREA.


&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...

LITTLE CHANGE DURING THIS PERIOD.

MEDIUM RANGE MODELS ARE TRENDING MORE TOWARDS A BROAD UPPER TROUGH
DEVELOPING OVER THE SOUTHEASTERN STATES...BENEATH AN UPPER RIDGE
LOCATED OVER THE OHIO VALLEY OVER THE WEEKEND. PERSISTENT DEEP
EASTERLY FLOW OFF THE ATLANTIC WILL BRING MOISTURE BACK INTO THE
FORECAST AREA BY SUNDAY AS PRECIPITABLE WATER VALUES INCREASE TO
OVER 1.25 INCHES. WILL CONTINUE WITH A DRY FORECAST ON SATURDAY
BUT RAIN CHANCES RETURN TO THE FORECAST SUNDAY THROUGH EARLY NEXT
WEEK. TEMPERATURES DURING THIS PERIOD SHOULD BE NEAR NORMAL. IT IS
WORTH NOTING THAT THIS IS A LOW CONFIDENCE FORECAST DUE TO THE
LACK OF RUN TO RUN CONSISTENCY AMONG THE MODELS AND RELATIVELY
WEAK FLOW PATTERN...LEADING TO A FORECAST DOMINATED BY SMALLER
SCALE FEATURES WHICH ARE TOUGH TO PINPOINT IN THE EXTENDED
PERIODS.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...

HIGH LOW-LEVEL MOISTURE AND THE SURFACE BOUNDARY WILL CONTINUE TO
DOMINATE DURING THE TAF PERIOD. EXPECT LITTLE THUNDERSTORM
COVERAGE DURING THE EARLY MORNING HOURS BECAUSE OF DIURNAL
COOLING. THE HIGH LOW-LEVEL MOISTURE WILL SUPPORT AREAS OF IFR
STRATUS AND FOG. IMPROVEMENT SHOULD OCCUR LATER IN THE MORNING
BECAUSE OF HEATING AND MIXING...BUT THE HEATING WILL LEAD TO MORE
THUNDERSTORMS. DID NOT INCLUDE THUNDERSTORMS IN THE TERMINAL
FORECASTS BECAUSE OF COVERAGE AND TIMING UNCERTAINTY.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR IFR STRATUS AND FOG
MAY OCCUR DURING THE EARLY MORNING HOURS THURSDAY AND FRIDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

SYNOPSIS...HC
NEAR TERM...RJL
SHORT TERM...HC
LONG TERM...HC
AVIATION...RJL

000
FXUS62 KCAE 160603
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
203 AM EDT WED MAY 16 2012

.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM EXTENDING THROUGH THE FORECAST AREA
TODAY WILL BE ALONG THE COAST THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
CONVERGENCE AND HIGH LOW-LEVEL MOISTURE ASSOCIATED WITH THE FRONT
PLUS COLD TEMPERATURES ALOFT SHOULD SUPPORT THUNDERSTORMS AGAIN
TODAY...MAINLY DURING THE TIME OF MAXIMUM HEATING. DEEPER MOISTURE
SUPPORTS SOMEWHAT HIGHER POPS IN THE EAST PART OF THE FORECAST
AREA. LEANED TOWARD THE NAM MOS POPS WHICH HAVE VERIFIED BETTER
LATELY AND APPEAR MORE REASONABLE BECAUSE OF THE SUPPORT. THE NAM
INDICATES MODERATE INSTABILITY AND EXPECT A FEW OF THE
THUNDERSTORMS WILL CONTAIN DAMAGING WIND AND HAIL. THE WARMER MAV
MOS TEMPERATURES MAY BE BETTER TODAY BASED ON YESTERDAY/S
VERIFICATION.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
CONVECTIVE ACTIVITY WILL DIMINISH WITH THE LOSS OF HEATING
WEDNESDAY EVENING...HOWEVER WITH OUTFLOW BOUNDARIES REMAINING OVER
THE FORECAST AREA BELIEVE CONVECTION WILL LINGER INTO THE LATE
EVENING/EARLY OVERNIGHT HOURS. ON THURSDAY THE FRONT WILL BE
OVER THE EASTERN MIDLANDS DURING THE AFTERNOON AND TRACKING
OFFSHORE DURING THE EVENING. INSTABILITY WILL BE LESS THAN
WEDNESDAY...HOWEVER THERE WILL STILL BE ENOUGH TO INITIATE
CONVECTION. BEST INSTABILITY WILL BE CLOSER TO THE FRONT SO WILL
AGAIN INCREASE POPS CLOSEST TO THE FRONT THEN EXPAND A BIT
WESTWARD AS OUTFLOWS TRIGGER SOME ADDITIONAL CONVECTION. SEVERE
THREAT WILL AGAIN BE FROM HAIL WITH LOWER POTENTIAL FOR DAMAGING
WINDS. HIGH TEMPERATURES THURSDAY AFTERNOON WILL GENERALLY BE IN
THE LOWER 80S. CONVECTION WILL DISSIPATE WITH LOSS OF HEATING AND
THE FRONT EDGING OFFSHORE. EXPECT SOME CONVECTION INTO THE EVENING
HOURS AND WITH THE FRONT MOVING OFFSHORE EXPECT CONVECTION TO END
BEFORE THE OVERNIGHT HOURS. LOW TEMPERATURES THURSDAY NIGHT WILL
BE A FEW DEGREES COOLER BEHIND THE FRONT WITH LOWS IN THE UPPER
50S TO LOWER 60S.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME
TYPICAL TIMING AND INTENSITY DIFFERENCES FOR SUNDAY AND MONDAY.
UPPER LEVEL TROUGH WILL EXIT THE REGION EARLY FRIDAY AS THE UPPER
LEVEL RIDGE BUILDS BACK IN. THIS WILL LEAVE A STATIONARY FRONT
ALONG THE COAST TO JUST SOUTH OF THE AREA. MODELS DIFFER ON THE
LOCATION OF THE FRONT...HOWEVER WITH HIGH PRESSURE DOMINATING THE
SURFACE EXPECT MUCH OF THE CONVECTIVE POTENTIAL TO BE SUPPRESSED
THROUGH THE WEEKEND. AS THE HIGH MOVES OFFSHORE MONDAY THE CHANCE
OF THUNDERSTORMS WILL RETURN. MODELS CONTINUE TO HAVE SIGNIFICANT
RUN TO RUN CHANGES ASSOCIATED WITH A LOW WHICH DEVELOPS ALONG THE
COAST. AS A RESULT HAVE REMAINED PESSIMISTIC CONCERNING THIS
FEATURE. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
HIGH LOW-LEVEL MOISTURE AND THE SURFACE BOUNDARY WILL CONTINUE TO
DOMINATE DURING THE TAF PERIOD. EXPECT LITTLE THUNDERSTORM
COVERAGE DURING THE EARLY MORNING HOURS BECAUSE OF DIURNAL
COOLING. THE HIGH LOW-LEVEL MOISTURE WILL SUPPORT AREAS OF IFR
STRATUS AND FOG. IMPROVEMENT SHOULD OCCUR LATER IN THE MORNING
BECAUSE OF HEATING AND MIXING...BUT THE HEATING WILL LEAD TO MORE
THUNDERSTORMS. DID NOT INCLUDE THUNDERSTORMS IN THE TERMINAL
FORECASTS BECAUSE OF COVERAGE AND TIMING UNCERTAINTY.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR IFR STRATUS AND FOG
MAY OCCUR DURING THE EARLY MORNING HOURS THURSDAY AND FRIDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KFFC 160600 AAC
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
200 AM EDT WED MAY 16 2012

.PREV DISCUSSION...

UPDATE...
/ISSUED 846 PM EDT TUE MAY 15 2012/
MAINLY ISOLATED SHOWERS/STORMS EXPECTED TO DISSIPATE THIS
EVENING. PATCHY LATE NIGHT/EARLY MORNING FOG AT LEAST POSSIBLE
AND INCLUDED.

 BDL

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED 216 PM EDT TUE MAY 15 2012/
A LARGE POSITIVELY TILTED TROUGH WAS LOCATED FROM OHIO SOUTH INTO
SOUTHERN TEXAS. THIS TROUGH HAS BEEN SLOWLY MOVING EAST WITH TIME.
WEAK SHORTWAVES HAVE BEEN TRANSVERSING THROUGH THE FLOW AND AIDING
IN SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN US. AT THE SURFACE
A STATIONARY FRONT WAS LOCATED ACROSS SOUTHERN GEORGIA. MODEL
SOUNDINGS AND CAPE VALUES TODAY SUGGEST THAT THUNDERSTORMS...AND
EVEN SOME STRONG THUNDERSTORMS ARE POSSIBLE TODAY. MODEL MUCAPE
VALUES RANGE FROM 2000 TO ALMOST 3000 J/KG ACROSS THE CWA TODAY.
WITH A BETTER DISTRIBUTION OF CAPE IN THE SOUNDING
TODAY...STRONGER UPDRAFTS SEEM POSSIBLE THIS AFTERNOON WITH ANY
THUNDERSTORMS THAT DEVELOP.

OVERNIGHT THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH.
WEDNESDAY...LOOKS LIKE THERE IS A CHANCE OF SHOWERS AND
THUNDERSTORMS AGAIN.  SOME OF THE HI-RES MODELS ARE INDICATING MORE
WIDESPREAD COVERAGE AND STRONGER STORMS ON WEDNESDAY.  THESE STORMS
SHOULD ALSO BE LIKE THE TYPICAL SUMMERTIME THUNDERSTORMS.  ON
THURSDAY WE SHOULD SEE ANOTHER CHANCE OF THUNDERSTORMS ALONG THE
STALLED OUT FRONTAL BOUNDARY ACROSS SOUTHERN GEORGIA.

TEMPERATURES WERE A BLEND OF THE MAV AND MET. NO OTHER TWEAKS WERE
MADE TO THEM.

GIBBS

LONG TERM /FRIDAY THROUGH TUESDAY/...
/ISSUED 216 PM EDT TUE MAY 15 2012/
UNCERTAINTY CONTINUES FOR THE LONG TERM WITH THE UPPER TROUGH
HOLDING OVER THE CWA. THEREFORE WILL MAKE NO CHANGES TO THE
CURRENT LONG TERM. SEE THE PREVIOUS LONG TERM DISCUSSION BELOW.

17

/ISSUED 411 AM EDT TUE MAY 15 2012/
LATEST GFS RUN A TAF SLOWER THAN PREVIOUS WITH AXIS OF UPPER TROF
SWINGING EAST OF THE COUNTY WARNING AREA AND UPPER RIDGE BUILDING
IN BEHIND IT. GFS NOW INDICATING A WEAK BOUNDARY APPROACHING THE
TENNESSEE VALLEY THURSDAY WITH SOME DEEPER MOISTURE SPREADING INTO
EXTREME NORTHERN COUNTIES. MODELS HOLD ON TO REMNANTS OF WEAK
BOUNDARY SOMEWHERE NEAR THE TN/WRN NC BORDER THURSDAY NIGHT BEFORE
WASHING IT FRIDAY AS HIGH PRESSURE WEDGES DOWN THE APPALACHIANS
AND REMAIN DOMINANT OVER OUR AREA THROUGH THE WEEKEND. ECMWF MOST
AGGRESSIVE WITH SHOWING A WEAK COASTAL LOW FORMING NEAR THE
SOUTHEAST COAST OVER THE WEEKEND...BUT BOTH ECMWF AND GFS SIMILAR
WITH KEEPING BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE EAST
AND SOUTH OF OUR AREA. MAY BE GETTING INTO BETTER CHANCES FOR
PRECIP MONDAY/TUESDAY WITH EXTENDED PROGS INDICATING A FRONTAL
BOUNDARY DRIFTING SOUTHEAST FROM THE OHIO/TENNESSEE VALLEY REGION.

49

&&

.AVIATION...
06Z UPDATE...
VFR CONDITIONS ACROSS THE TAF SITES AND GENERALLY EXPECTED TO
CONTINUE THROUGH THE FORECAST PERIOD. THE EXCEPTION TO THIS MAY BE
SOME MVFR VSBYS AT THE USUAL FOG SITES...FTY...AHN AND MCN.
CONFIDENCE IS LOW ON JUST HOW LOW THESE SITES WILL GO. EXPECT CU
TO DEVELOP LATE THIS MORNING. ALTHOUGH THUNDERSTORM CHANCES AT
THE TAF SITES ARE LOW...DID INCLUDE PROB30 AT MCN AND AHN THAT
HAVE THE BEST CHANCES. WEST WINDS WILL BECOME MORE NW TODAY AT
ATL.

//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ON WINDS...CIGS AND VSBYS.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          85  59  84  59 /  20  20  10  10
ATLANTA         83  61  83  63 /  10  10  10  10
BLAIRSVILLE     79  53  79  56 /  10  10  20  20
CARTERSVILLE    84  56  84  56 /  10  10  20  10
COLUMBUS        86  62  86  63 /  10  10  10  10
GAINESVILLE     82  59  81  59 /  10  10  20  10
MACON           86  60  86  61 /  30  20  20  10
ROME            84  55  85  57 /  10   5  10  10
PEACHTREE CITY  83  56  84  57 /  10  10  10  10
VIDALIA         88  65  87  65 /  30  20  30  10

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS62 KCHS 160545
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
145 AM EDT WED MAY 16 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OVERNIGHT...ADJUSTED INLAND POPS TO CHANCE FOR A WHILE LONGER
ALONG AND W OF THE I-95 CORRIDOR WHERE ONGOING ACTIVITY CONTINUES.
MOST OF THE 00Z GUIDANCE SUGGEST COVERAGE WILL DIMINISH LATE.
SOME LOW CLOUDS ARE A GOOD BET ALONG COASTAL AREAS BUT OVERALL
CHANCES FOR SIGNIFICANT FOG LOOK LOW AS LAYERED CLOUDS PERSIST.
NO CHANGE TO LOWS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
ALTHOUGH A BROAD UPPER TROUGH WILL PERSIST OVER THE SOUTHEAST UNITED
STATES WEDNESDAY THROUGH FRIDAY...THE PRIMARY UPPER LOW WILL MOVE
THROUGH THE FORECAST AREA THURSDAY AND OFFSHORE BY FRIDAY. QUITE A
BIT OF SHORTWAVE ENERGY LIFTING OUT OF THE NORTHEAST GULF OF MEXICO
WEDNESDAY AND THURSDAY...COINCIDENT WITH RELATIVELY MOIST BOUNDARY
LAYER AND DIURNAL HEATING...SHOULD RESULT IN GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOONS. A COLD
FRONT IS PROGGED TO DROP INTO THE NORTHERN HALF OF THE AREA ON
THURSDAY WHICH WILL PROVIDE AN ADDITIONAL FOCUS FOR CONVECTION.
SEVERE THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY OR THURSDAY DUE
TO THE ABUNDANCE OF FORCING MECHANISMS AND REASONABLY HIGH
CONVECTIVE INDICES.

THE FRONT WILL DROP THROUGH THURSDAY NIGHT WITH HIGH PRESSURE
BUILDING DOWN THE COAST ON FRIDAY. CONVECTION WILL STILL BE POSSIBLE
OVER OUR FAR SOUTHERN GA ZONES AS THE FRONT STALLS ALONG THE
ALTAMAHA RIVER.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THROUGH DAYBREAK...CONCERN FOR AREAS OF MVFR/IFR CIGS WITH
INDICATIONS THAT KSAV HAS A BETTER POTENTIAL SINCE LOW-END MVFR
CIGS ALREADY NOTED ON 05Z OBSERVATIONS. CONVECTIVE RAINS SW OF
KSAV SHOULD REMAIN JUST SW TO W OF THE TERMINAL BUT CONFIDENCE ON
HOW MESOSCALE TRENDS PLAY OUT OVERNIGHT IS NOT GREAT...ALTHOUGH
PCPN COVERAGE SHOULD DIMINISH TOWARD DAYBREAK. WE HAVE MAINTAINED
TRENDS FROM THE 00Z TAF CYCLE FOR THE MOST PART.

ANOTHER ROUND OF DIURNAL CONVECTION SEEMS A GOOD BET THIS AFTERNOON
AND POSSIBLY INTO THE EVENING ALONG PARTS OF THE COASTAL CORRIDOR.
WE HAVE MAINTAINED PROBS FOR BEST CHANCE TIMING IN THE MID/LATE
DAY HOURS.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS
WILL BE POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL
SHRA/TSRA. VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND
SATURDAY.

&&

.MARINE...
WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
ON THE EAST SIDE OF BROAD LOW PRESSURE. SEA BREEZE ENHANCEMENT
COULD SUPPORT LOCAL WINDS AS HIGH AS 15-20 KT THIS AFTERNOON/EARLY
EVENING...ESPECIALLY ON CHARLESTON HARBOR. OTHERWISE...WINDS OF 15
KT OR LESS ARE EXPECTED. MAINTAINED SEAS FROM 2-4 FT WITHIN 20 NM
TO 4 FT 20-60 NM.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE WEEKEND...
WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER WINDS AND
LARGER SEAS FRIDAY THROUGH SUNDAY. SMALL CRAFT ADVISORIES SEEM
ALMOST A CERTAINTY DURING THAT TIME.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...JRL
LONG TERM...
AVIATION...
MARINE...JRL/SPR

000
FXUS62 KCAE 160344
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1144 PM EDT TUE MAY 15 2012

.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN IN THE FORECAST AREA THROUGH
WEDNESDAY. SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION
THURSDAY AND PROVIDE DRY WEATHER THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/...
THE BOUNDARY WILL REMAIN IN THE AREA OVERNIGHT AND MAY SUPPORT
ADDITIONAL SHOWERS AND THUNDERSTORMS. HOWEVER...EXPECT LITTLE
COVERAGE BECAUSE OF THE LOSS OF HEATING. THE HIGH LOW-LEVEL
MOISTURE WILL SUPPORT AREAS OF FOG. EXPECT LOWS IN THE LOWER TO
MIDDLE 60S.

&&

.SHORT TERM /8 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
LOW PRESSURE WILL BE TRACKING FROM NEW ENGLAND INTO THE FAR EASTERN
CANADIAN PROVINCES AS A WEAK FRONTAL BOUNDARY SLOWLY CROSSES THE
FORECAST AREA. ON WEDNESDAY THE FRONT WILL BE OVER THE UPSTATE WITH
ANOTHER UNSTABLE DAY FOR CONVECTIVE ACTIVITY. WITH AROUND 2000 J/KG
CAPE AND LI/S AROUND -5 EXPECT ANOTHER AFTERNOON AND EVENING WITH
SCATTERED SHOWERS AND THUNDERSTORMS. MODELS INDICATE THE BEST
INSTABILITY OVER THE EASTERN MIDLANDS AND...WITH THE POSITION OF THE
FRONT AND HIGHER MOISTURE IN THE EASTERN MIDLANDS...AGREE HIGHEST
POPS TO START IN THAT AREA. WILL EXPAND POPS TO THE REMAINDER OF THE
AREA AS PLENTIFUL INSTABILITY COMBINING WITH OUTFLOWS WILL LIKELY
SPUR ADDITIONAL ACTIVITY. SPC CONTINUES TO KEEP THE REGION IN
GENERAL THUNDER WHICH CURRENTLY SEEMS APPROPRIATE. MAIN THREAT OF
SEVERE ON WEDNESDAY AFTERNOON WILL BE HAIL WITH A LOWER CHANCE FOR
WIND GUSTS. CONVECTIVE ACTIVITY WILL DIMINISH WITH THE LOSS OF
HEATING WEDNESDAY EVENING...HOWEVER WITH OUTFLOW BOUNDARIES REMAINING
OVER THE FORECAST AREA BELIEVE CONVECTION WILL LINGER INTO THE LATE
EVENING/EARLY OVERNIGHT HOURS. AFTERNOON HIGH TEMPERATURES
WEDNESDAY WILL GENERALLY BE IN THE MIDDLE 80S. WITH SOME LINGERING
CLOUDS AND PATCHY FOG EXPECT OVERNIGHT LOWS WEDNESDAY NIGHT IN THE
LOWER 60S.

ON THURSDAY THE FRONT WILL BE OVER THE EASTERN MIDLANDS DURING THE
AFTERNOON AND TRACKING OFFSHORE DURING THE EVENING. INSTABILITY WILL
BE LESS THAN WEDNESDAY...HOWEVER THERE WILL STILL BE ENOUGH TO
INITIATE CONVECTION. BEST INSTABILITY WILL BE CLOSER TO THE FRONT SO
WILL AGAIN INCREASE POPS CLOSEST TO THE FRONT THEN EXPAND A BIT
WESTWARD AS OUTFLOWS TRIGGER SOME ADDITIONAL CONVECTION. SEVERE
THREAT WILL AGAIN BE FROM HAIL WITH LOWER POTENTIAL FOR DAMAGING
WINDS. HIGH TEMPERATURES THURSDAY AFTERNOON WILL GENERALLY BE IN THE
LOWER 80S. CONVECTION WILL DISSIPATE WITH LOSS OF HEATING AND THE
FRONT EDGING OFFSHORE. EXPECT SOME CONVECTION INTO THE EVENING HOURS
AND WITH THE FRONT MOVING OFFSHORE EXPECT CONVECTION TO END BEFORE
THE OVERNIGHT HOURS. LOW TEMPERATURES THURSDAY NIGHT WILL BE A FEW
DEGREES COOLER BEHIND THE FRONT WITH LOWS IN THE UPPER 50S TO LOWER
60S.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME
TYPICAL TIMING AND INTENSITY DIFFERENCES FOR SUNDAY AND MONDAY.
UPPER LEVEL TROUGH WILL EXIT THE REGION EARLY FRIDAY AS THE UPPER
LEVEL RIDGE BUILDS BACK IN. THIS WILL LEAVE A STATIONARY FRONT
ALONG THE COAST TO JUST SOUTH OF THE AREA. MODELS DIFFER ON THE
LOCATION OF THE FRONT...HOWEVER WITH HIGH PRESSURE DOMINATING THE
SURFACE EXPECT MUCH OF THE CONVECTIVE POTENTIAL TO BE SUPPRESSED
THROUGH THE WEEKEND. AS THE HIGH MOVES OFFSHORE MONDAY THE CHANCE
OF THUNDERSTORMS WILL RETURN. MODELS CONTINUE TO HAVE SIGNIFICANT
RUN TO RUN CHANGES ASSOCIATED WITH A LOW WHICH DEVELOPS ALONG THE
COAST. AS A RESULT HAVE REMAINED PESSIMISTIC CONCERNING THIS
FEATURE. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.

&&

.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
HIGH LOW-LEVEL MOISTURE AND THE SURFACE BOUNDARY WILL CONTINUE TO
DOMINATE DURING THE TAF PERIOD. EXPECT LITTLE THUNDERSTORM
COVERAGE DURING THE EARLY MORNING HOURS BECAUSE OF DIURNAL
COOLING. THE HIGH LOW-LEVEL MOISTURE WILL SUPPORT AREAS OF IFR
STRATUS AND FOG. IMPROVEMENT SHOULD OCCUR LATER IN THE MORNING
BECAUSE OF HEATING AND MIXING...BUT THE HEATING WILL LEAD TO MORE
THUNDERSTORMS. DID NOT INCLUDE THUNDERSTORMS IN THE TERMINAL
FORECASTS BECAUSE OF COVERAGE AND TIMING UNCERTAINTY.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR IFR STRATUS AND FOG
MAY OCCUR DURING THE EARLY MORNING HOURS THURSDAY AND FRIDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KCHS 160252
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1052 PM EDT TUE MAY 15 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATE THIS EVENING...ONLY ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS PERSIST ACROSS INTERIOR SE GA. THIS ACTIVITY SHOULD
PRIMARILY REMAIN CONFINED TO THIS AREA...BUT ISOLATED
SHOWERS/STORMS WILL BE POSSIBLE FOR THE NEXT SEVERAL HOURS DUE TO
LINGERING OUTFLOW BOUNDARIES FROM EARLIER CONVECTION. OTHERWISE
THE REST OF THE OVERNIGHT WILL BE QUIET WITH JUST THE POTENTIAL
FOR THE DEVELOPMENT OF STRATUS AND FOG. THIS WILL MAINLY BE A
THREAT IN AREAS DIRECTLY AFFECTED BY THUNDERSTORMS THIS AFTERNOON.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
ALTHOUGH A BROAD UPPER TROUGH WILL PERSIST OVER THE SOUTHEAST UNITED
STATES WEDNESDAY THROUGH FRIDAY...THE PRIMARY UPPER LOW WILL MOVE
THROUGH THE FORECAST AREA THURSDAY AND OFFSHORE BY FRIDAY. QUITE A
BIT OF SHORTWAVE ENERGY LIFTING OUT OF THE NORTHEAST GULF OF MEXICO
WEDNESDAY AND THURSDAY...COINCIDENT WITH RELATIVELY MOIST BOUNDARY
LAYER AND DIURNAL HEATING...SHOULD RESULT IN GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOONS. A COLD
FRONT IS PROGGED TO DROP INTO THE NORTHERN HALF OF THE AREA ON
THURSDAY WHICH WILL PROVIDE AN ADDITIONAL FOCUS FOR CONVECTION.
SEVERE THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY OR THURSDAY DUE
TO THE ABUNDANCE OF FORCING MECHANISMS AND REASONABLY HIGH
CONVECTIVE INDICES.

THE FRONT WILL DROP THROUGH THURSDAY NIGHT WITH HIGH PRESSURE
BUILDING DOWN THE COAST ON FRIDAY. CONVECTION WILL STILL BE POSSIBLE
OVER OUR FAR SOUTHERN GA ZONES AS THE FRONT STALLS ALONG THE
ALTAMAHA RIVER.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
COVERAGE OF THUNDERSTORMS HAS GREATLY DIMINISHED THIS EVENING AND
IS EXPECTED TO STAY AWAY FROM THE TERMINALS THROUGH THE NEXT FEW
HOURS. THERE ARE A COUPLE OF SHOWERS AND STORMS WELL WEST OF
KSAV...BUT THESE ARE ON THE DOWNWARD TREND AND I DON/T ANTICIPATE
THEM AFFECTING THE SITE. THE FOCUS OF THE FORECAST THEN TURNS TO
THE POTENTIAL FOR FOG/STRATUS DEVELOPMENT OVERNIGHT. KSAV ONCE
AGAIN TOOK A DIRECT HIT FROM A THUNDERSTORM THIS AFTERNOON...SO
THE PROBABILITY IS HIGHEST THERE. GUIDANCE FAVORS IFR CONDITIONS
FOR A FEW HOURS...AND SINCE THEY ALSO HAD IT YESTERDAY IT SEEMS
LIKE A REASONABLE OUTCOME. I HAVE GONE WITH PREVAILING MVFR CIGS
STARTING AT 08Z WITH A TEMPO TILL 12Z FOR IFR CIGS. EVEN THOUGH
SURFACE WINDS WILL LIKELY GO CALM...THERE IS ENOUGH FLOW IN THE
LOWEST FEW HUNDRED FEET TO LIKELY FAVOR STRATUS OVER FOG. THE
PROBABILITY AT KCHS IS MUCH LOWER...AND I HAVE GONE WITH A PERIOD
OF JUST GROUND FOG THERE.

ANOTHER ROUND OF AFTERNOON/EVENING THUNDERSTORMS IS EXPECTED ON
WEDNESDAY. I HAVE ADDED A PROB30 GROUP TO BOTH SITES BETWEEN 19-23Z.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
ON THE EAST SIDE OF BROAD LOW PRESSURE. SEA BREEZE ENHANCEMENT
COULD SUPPORT LOCAL WINDS AS HIGH AS 15-20 KT THIS AFTERNOON/EARLY
EVENING...ESPECIALLY ON CHARLESTON HARBOR. OTHERWISE...WINDS OF 15
KTS OR LESS ARE EXPECTED. MAINTAINED SEAS FROM 2-4 FT WITHIN 20 NM
TO 4 FT 20-60 NM.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE WEEKEND...
WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER WINDS AND
LARGER SEAS FRIDAY THROUGH SUNDAY. SMALL CRAFT ADVISORIES SEEM
ALMOST A CERTAINTY DURING THAT TIME.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...
AVIATION...BSH
MARINE...JRL/SPR

000
FXUS62 KCHS 160111
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
911 PM EDT TUE MAY 15 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
ANOTHER QUICK UPDATE TO CLEAR THE WATCH FOR THE REMAINING
COUNTIES. OTHER THAN A FEW LINGERING SHOWERS/STORMS JUST ENTERING
THE SC GA ZONES...MOST AREAS ARE PRECIP FREE RIGHT NOW. WITH
RESIDUAL BOUNDARIES FLOATING AROUND...A FEW SHOWERS COULD DEVELOP
THROUGH THE NEXT FEW HOURS.

OVERNIGHT INTO EARLY WEDNESDAY...AREAS OF STRATUS AND/OR FOG
COULD DEVELOP...ESPECIALLY WHERE HEAVY RAIN WAS RECORDED THIS
AFTERNOON/EVENING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
ALTHOUGH A BROAD UPPER TROUGH WILL PERSIST OVER THE SOUTHEAST UNITED
STATES WEDNESDAY THROUGH FRIDAY...THE PRIMARY UPPER LOW WILL MOVE
THROUGH THE FORECAST AREA THURSDAY AND OFFSHORE BY FRIDAY. QUITE A
BIT OF SHORTWAVE ENERGY LIFTING OUT OF THE NORTHEAST GULF OF MEXICO
WEDNESDAY AND THURSDAY...COINCIDENT WITH RELATIVELY MOIST BOUNDARY
LAYER AND DIURNAL HEATING...SHOULD RESULT IN GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOONS. A COLD
FRONT IS PROGGED TO DROP INTO THE NORTHERN HALF OF THE AREA ON
THURSDAY WHICH WILL PROVIDE AN ADDITIONAL FOCUS FOR CONVECTION.
SEVERE THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY OR THURSDAY DUE
TO THE ABUNDANCE OF FORCING MECHANISMS AND REASONABLY HIGH
CONVECTIVE INDICES.

THE FRONT WILL DROP THROUGH THURSDAY NIGHT WITH HIGH PRESSURE
BUILDING DOWN THE COAST ON FRIDAY. CONVECTION WILL STILL BE POSSIBLE
OVER OUR FAR SOUTHERN GA ZONES AS THE FRONT STALLS ALONG THE
ALTAMAHA RIVER.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
COVERAGE OF THUNDERSTORMS HAS GREATLY DIMINISHED THIS EVENING AND
IS EXPECTED TO STAY AWAY FROM THE TERMINALS THROUGH THE NEXT FEW
HOURS. THERE ARE A COUPLE OF SHOWERS AND STORMS WELL WEST OF
KSAV...BUT THESE ARE ON THE DOWNWARD TREND AND I DON/T ANTICIPATE
THEM AFFECTING THE SITE. THE FOCUS OF THE FORECAST THEN TURNS TO
THE POTENTIAL FOR FOG/STRATUS DEVELOPMENT OVERNIGHT. KSAV ONCE
AGAIN TOOK A DIRECT HIT FROM A THUNDERSTORM THIS AFTERNOON...SO
THE PROBABILITY IS HIGHEST THERE. GUIDANCE FAVORS IFR CONDITIONS
FOR A FEW HOURS...AND SINCE THEY ALSO HAD IT YESTERDAY IT SEEMS
LIKE A REASONABLE OUTCOME. I HAVE GONE WITH PREVAILING MVFR CIGS
STARTING AT 08Z WITH A TEMPO TILL 12Z FOR IFR CIGS. EVEN THOUGH
SURFACE WINDS WILL LIKELY GO CALM...THERE IS ENOUGH FLOW IN THE
LOWEST FEW HUNDRED FEET TO LIKELY FAVOR STRATUS OVER FOG. THE
PROBABILITY AT KCHS IS MUCH LOWER...AND I HAVE GONE WITH A PERIOD
OF JUST GROUND FOG THERE.

ANOTHER ROUND OF AFTERNOON/EVENING THUNDERSTORMS IS EXPECTED ON
WEDNESDAY. I HAVE ADDED A PROB30 GROUP TO BOTH SITES BETWEEN 19-23Z.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
ON THE EAST SIDE OF BROAD LOW PRESSURE. SEA BREEZE ENHANCEMENT
COULD SUPPORT LOCAL WINDS AS HIGH AS 15-20 KT THIS AFTERNOON/EARLY
EVENING...ESPECIALLY ON CHARLESTON HARBOR. OTHERWISE...WINDS OF 15
KTS OR LESS ARE EXPECTED. MAINTAINED SEAS FROM 2-4 FT WITHIN 20 NM
TO 4 FT 20-60 NM.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE WEEKEND...
WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER WINDS AND
LARGER SEAS FRIDAY THROUGH SUNDAY. SMALL CRAFT ADVISORIES SEEM
ALMOST A CERTAINTY DURING THAT TIME.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

NEAR TERM...SPR/BSH
SHORT TERM...JRL
LONG TERM...
AVIATION...BSH
MARINE...JRL/SPR

000
FXUS62 KCAE 160103
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
903 PM EDT TUE MAY 15 2012

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY ACROSS THE REGION WILL PROVIDE A FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING. THE FRONT WILL
SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE INCREASED CHANCES
OF THUNDERSTORMS ACROSS THE EASTERN MIDLANDS ON WEDNESDAY BEFORE
SHIFTING TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD INTO THE
REGION THURSDAY AND PROVIDE DRY WEATHER THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/...
WIDESPREAD CONVECTION CURRENTLY CROSSING THE MIDLANDS AT 9 PM
EXPECTED TO DECREASE IN NUMBER AND INTENSITY THROUGH THE EVENING
HOURS AS LOW LEVEL STABILIZATION TAKES PLACE. .

ISOLATED STRONG TO SEVERE STORMS WITH HAIL AND DAMAGING WINDS
POSSIBLE FOR THE NEXT COUPLE OF HOURS. HAVE INCREASED POPS FOR THE
CENTRAL/EASTERN MIDLANDS FOR THE REST OF THE EVENING. POPS 20
PERCENT OR LESS AFTER MIDNIGHT WITH LOSS OF HEATING.

THERE MAY BE SOME PATCHY FOG AFTER MIDNIGHT. OVERNIGHT LOWS IN THE
LOW TO MID 60S.

&&

.SHORT TERM /8 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
LOW PRESSURE WILL BE TRACKING FROM NEW ENGLAND INTO THE FAR EASTERN
CANADIAN PROVINCES AS A WEAK FRONTAL BOUNDARY SLOWLY CROSSES THE
FORECAST AREA. ON WEDNESDAY THE FRONT WILL BE OVER THE UPSTATE WITH
ANOTHER UNSTABLE DAY FOR CONVECTIVE ACTIVITY. WITH AROUND 2000 J/KG
CAPE AND LI/S AROUND -5 EXPECT ANOTHER AFTERNOON AND EVENING WITH
SCATTERED SHOWERS AND THUNDERSTORMS. MODELS INDICATE THE BEST
INSTABILITY OVER THE EASTERN MIDLANDS AND...WITH THE POSITION OF THE
FRONT AND HIGHER MOISTURE IN THE EASTERN MIDLANDS...AGREE HIGHEST
POPS TO START IN THAT AREA. WILL EXPAND POPS TO THE REMAINDER OF THE
AREA AS PLENTIFUL INSTABILITY COMBINING WITH OUTFLOWS WILL LIKELY
SPUR ADDITIONAL ACTIVITY. SPC CONTINUES TO KEEP THE REGION IN
GENERAL THUNDER WHICH CURRENTLY SEEMS APPROPRIATE. MAIN THREAT OF
SEVERE ON WEDNESDAY AFTERNOON WILL BE HAIL WITH A LOWER CHANCE FOR
WIND GUSTS. CONVECTIVE ACTIVITY WILL DIMINISH WITH THE LOSS OF
HEATING WEDNESDAY EVENING...HOWEVER WITH OUTFLOW BOUNDARIES REMAINING
OVER THE FORECAST AREA BELIEVE CONVECTION WILL LINGER INTO THE LATE
EVENING/EARLY OVERNIGHT HOURS. AFTERNOON HIGH TEMPERATURES
WEDNESDAY WILL GENERALLY BE IN THE MIDDLE 80S. WITH SOME LINGERING
CLOUDS AND PATCHY FOG EXPECT OVERNIGHT LOWS WEDNESDAY NIGHT IN THE
LOWER 60S.

ON THURSDAY THE FRONT WILL BE OVER THE EASTERN MIDLANDS DURING THE
AFTERNOON AND TRACKING OFFSHORE DURING THE EVENING. INSTABILITY WILL
BE LESS THAN WEDNESDAY...HOWEVER THERE WILL STILL BE ENOUGH TO
INITIATE CONVECTION. BEST INSTABILITY WILL BE CLOSER TO THE FRONT SO
WILL AGAIN INCREASE POPS CLOSEST TO THE FRONT THEN EXPAND A BIT
WESTWARD AS OUTFLOWS TRIGGER SOME ADDITIONAL CONVECTION. SEVERE
THREAT WILL AGAIN BE FROM HAIL WITH LOWER POTENTIAL FOR DAMAGING
WINDS. HIGH TEMPERATURES THURSDAY AFTERNOON WILL GENERALLY BE IN THE
LOWER 80S. CONVECTION WILL DISSIPATE WITH LOSS OF HEATING AND THE
FRONT EDGING OFFSHORE. EXPECT SOME CONVECTION INTO THE EVENING HOURS
AND WITH THE FRONT MOVING OFFSHORE EXPECT CONVECTION TO END BEFORE
THE OVERNIGHT HOURS. LOW TEMPERATURES THURSDAY NIGHT WILL BE A FEW
DEGREES COOLER BEHIND THE FRONT WITH LOWS IN THE UPPER 50S TO LOWER
60S.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME
TYPICAL TIMING AND INTENSITY DIFFERENCES FOR SUNDAY AND MONDAY.
UPPER LEVEL TROUGH WILL EXIT THE REGION EARLY FRIDAY AS THE UPPER
LEVEL RIDGE BUILDS BACK IN. THIS WILL LEAVE A STATIONARY FRONT
ALONG THE COAST TO JUST SOUTH OF THE AREA. MODELS DIFFER ON THE
LOCATION OF THE FRONT...HOWEVER WITH HIGH PRESSURE DOMINATING THE
SURFACE EXPECT MUCH OF THE CONVECTIVE POTENTIAL TO BE SUPPRESSED
THROUGH THE WEEKEND. AS THE HIGH MOVES OFFSHORE MONDAY THE CHANCE
OF THUNDERSTORMS WILL RETURN. MODELS CONTINUE TO HAVE SIGNIFICANT
RUN TO RUN CHANGES ASSOCIATED WITH A LOW WHICH DEVELOPS ALONG THE
COAST. AS A RESULT HAVE REMAINED PESSIMISTIC CONCERNING THIS
FEATURE. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
UPPER TROUGH STILL TO THE WEST BRINGING MOISTURE TO AREA.
WEAK FRONTAL BOUNDARY ACROSS THE REGION AND LEFT OVER OUTFLOW
BOUNDARIES FROM CONVECTIVE ACTIVITY SHOULD PROVIDE A FOCUS FOR
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. MAINLY VFR
CONDITIONS BUT BRIEF IFR-MVFR CONDITIONS ARE POSSIBLE IN CONVECTIVE
ACTIVITY. DECIDED NOT TO INCLUDE IN TAFS SITES DUE TO UNCERTAINTY
AS TO TIMING AND COVERAGE. ACTIVITY IS EXPECTED TO TAPER OFF 03Z-04Z
TIME FRAME BUT MAY LINGER NORTH AND EAST OF TAF SITES. AFTER
MIDNIGHT WITH PLENTY OF MOISTURE AND LEFT OVER CLOUDS...NO AS MUCH
FOG EXPECTED BUT STRATUS WILL PROBABLY DEVELOP AGAIN. EXPECT IFR
CEILINGS TO DEVELOP BEFORE DAYBREAK WEDNESDAY. THE UPPER TROUGH
SHOULD HAVE SHIFTED EASTWARD BY WEDNESDAY BUT THERE WILL STILL BE
ENOUGH MOISTURE AND INSTABILITY FOR SOME AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. WILL GO VFR BUT LOWER CONDITIONS MAY
OCCUR IN CONVECTIVE ACTIVITY.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS ARE
EXPECTED WEDNESDAY NIGHT THROUGH SUNDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KFFC 160046 AAB
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
846 PM EDT TUE MAY 15 2012

.UPDATE...
MAINLY ISOLATED SHOWERS/STORMS EXPECTED TO DISSIPATE THIS
EVENING. PATCHY LATE NIGHT/EARLY MORNING FOG AT LEAST POSSIBLE
AND INCLUDED. BDL

&&

.PREV DISCUSSION... /ISSUED 715 PM EDT TUE MAY 15 2012/

PREV DISCUSSION... /ISSUED 216 PM EDT TUE MAY 15 2012/

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
A LARGE POSITIVELY TILTED TROUGH WAS LOCATED FROM OHIO SOUTH INTO
SOUTHERN TEXAS. THIS TROUGH HAS BEEN SLOWLY MOVING EAST WITH TIME.
WEAK SHORTWAVES HAVE BEEN TRANSVERSING THROUGH THE FLOW AND AIDING
IN SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN US. AT THE SURFACE
A STATIONARY FRONT WAS LOCATED ACROSS SOUTHERN GEORGIA. MODEL
SOUNDINGS AND CAPE VALUES TODAY SUGGEST THAT THUNDERSTORMS...AND
EVEN SOME STRONG THUNDERSTORMS ARE POSSIBLE TODAY. MODEL MUCAPE
VALUES RANGE FROM 2000 TO ALMOST 3000 J/KG ACROSS THE CWA TODAY.
WITH A BETTER DISTRIBUTION OF CAPE IN THE SOUNDING
TODAY...STRONGER UPDRAFTS SEEM POSSIBLE THIS AFTERNOON WITH ANY
THUNDERSTORMS THAT DEVELOP.

OVERNIGHT THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH.
WEDNESDAY...LOOKS LIKE THERE IS A CHANCE OF SHOWERS AND
THUNDERSTORMS AGAIN.  SOME OF THE HI-RES MODELS ARE INDICATING MORE
WIDESPREAD COVERAGE AND STRONGER STORMS ON WEDNESDAY.  THESE STORMS
SHOULD ALSO BE LIKE THE TYPICAL SUMMERTIME THUNDERSTORMS.  ON
THURSDAY WE SHOULD SEE ANOTHER CHANCE OF THUNDERSTORMS ALONG THE
STALLED OUT FRONTAL BOUNDARY ACROSS SOUTHERN GEORGIA.

TEMPERATURES WERE A BLEND OF THE MAV AND MET. NO OTHER TWEAKS WERE
MADE TO THEM.

GIBBS

LONG TERM /FRIDAY THROUGH TUESDAY/...
UNCERTAINTY CONTINUES FOR THE LONG TERM WITH THE UPPER TROUGH
HOLDING OVER THE CWA. THEREFORE WILL MAKE NO CHANGES TO THE
CURRENT LONG TERM. SEE THE PREVIOUS LONG TERM DISCUSSION BELOW...

/ISSUED 411 AM EDT TUE MAY 15 2012/
LATEST GFS RUN A TAF SLOWER THAN PREVIOUS WITH AXIS OF UPPER TROF
SWINGING EAST OF THE COUNTY WARNING AREA AND UPPER RIDGE BUILDING
IN BEHIND IT. GFS NOW INDICATING A WEAK BOUNDARY APPROACHING THE
TENNESSEE VALLEY THURSDAY WITH SOME DEEPER MOISTURE SPREADING INTO
EXTREME NORTHERN COUNTIES. MODELS HOLD ON TO REMNANTS OF WEAK
BOUNDARY SOMEWHERE NEAR THE TN/WRN NC BORDER THURSDAY NIGHT BEFORE
WASHING IT FRIDAY AS HIGH PRESSURE WEDGES DOWN THE APPALACHIANS
AND REMAIN DOMINANT OVER OUR AREA THROUGH THE WEEKEND. ECMWF MOST
AGGRESSIVE WITH SHOWING A WEAK COASTAL LOW FORMING NEAR THE
SOUTHEAST COAST OVER THE WEEKEND...BUT BOTH ECMWF AND GFS SIMILAR
WITH KEEPING BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE EAST
AND SOUTH OF OUR AREA. MAY BE GETTING INTO BETTER CHANCES FOR
PRECIP MONDAY/TUESDAY WITH EXTENDED PROGS INDICATING A FRONTAL
BOUNDARY DRIFTING SOUTHEAST FROM THE OHIO/TENNESSEE VALLEY REGION.

49

AVIATION...
00Z UPDATE...
MAINLY VFR CONDITIONS OVERNIGHT. AREA MAINLY SHOWERS APPROACHING
ATL AREA TAFS SHOULD PROVIDE ONLY BRIEF LOWER VFR CONDITIONS.
PATCHY MVFR VSBYS LATE NIGHT-EARLY MORNING. SURFACE WINDS LIGHT WNW
BECOMING CALM FOR MANY AREAS. BDL

//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          60  85  59  84 /  20  20  20  10
ATLANTA         62  83  61  83 /  20  10  10  10
BLAIRSVILLE     54  79  53  79 /  20  10  10  20
CARTERSVILLE    57  84  56  84 /  20  10  10  20
COLUMBUS        63  86  62  86 /  20  10  10  10
GAINESVILLE     60  82  59  81 /  20  10  10  20
MACON           61  86  60  86 /  20  30  20  20
ROME            57  84  55  85 /  20  10   5  10
PEACHTREE CITY  58  83  56  84 /  20  10  10  10
VIDALIA         67  88  65  87 /  50  30  20  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...LYNN
LONG TERM....DEESE
AVIATION...LYNN

000
FXUS62 KCHS 160009
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
809 PM EDT TUE MAY 15 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
UPDATE TO CLEAR A TIER OF COUNTIES ALONG THE COAST FROM THE WATCH.
CONVECTION HAS DIMINISHED GREATLY IN COVERAGE AND INTENSITY AND THE
REMAINDER OF THE AREA WILL BE ABLE TO COME OUT OF THE WATCH AT 9PM
AS EXPECTED.

PER DIURNAL TRENDS...THUNDERSTORMS WILL DECREASE IN COVERAGE AND
INTENSITY TONIGHT...AND THE REGION SHOULD BECOME MAINLY
PRECIPITATION FREE OVERNIGHT.

OVERNIGHT INTO EARLY WEDNESDAY...AREAS OF STRATUS AND/OR FOG COULD
DEVELOP WHERE HEAVY RAIN OCCURS THIS AFTERNOON/EVENING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
ALTHOUGH A BROAD UPPER TROUGH WILL PERSIST OVER THE SOUTHEAST UNITED
STATES WEDNESDAY THROUGH FRIDAY...THE PRIMARY UPPER LOW WILL MOVE
THROUGH THE FORECAST AREA THURSDAY AND OFFSHORE BY FRIDAY. QUITE A
BIT OF SHORTWAVE ENERGY LIFTING OUT OF THE NORTHEAST GULF OF MEXICO
WEDNESDAY AND THURSDAY...COINCIDENT WITH RELATIVELY MOIST BOUNDARY
LAYER AND DIURNAL HEATING...SHOULD RESULT IN GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOONS. A COLD
FRONT IS PROGGED TO DROP INTO THE NORTHERN HALF OF THE AREA ON
THURSDAY WHICH WILL PROVIDE AN ADDITIONAL FOCUS FOR CONVECTION.
SEVERE THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY OR THURSDAY DUE
TO THE ABUNDANCE OF FORCING MECHANISMS AND REASONABLY HIGH
CONVECTIVE INDICES.

THE FRONT WILL DROP THROUGH THURSDAY NIGHT WITH HIGH PRESSURE
BUILDING DOWN THE COAST ON FRIDAY. CONVECTION WILL STILL BE POSSIBLE
OVER OUR FAR SOUTHERN GA ZONES AS THE FRONT STALLS ALONG THE
ALTAMAHA RIVER.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
COVERAGE OF THUNDERSTORMS HAS GREATLY DIMINISHED THIS EVENING AND
IS EXPECTED TO STAY AWAY FROM THE TERMINALS THROUGH THE NEXT FEW
HOURS. THERE ARE A COUPLE OF SHOWERS AND STORMS WELL WEST OF
KSAV...BUT THESE ARE ON THE DOWNWARD TREND AND I DON/T ANTICIPATE
THEM AFFECTING THE SITE. THE FOCUS OF THE FORECAST THEN TURNS TO
THE POTENTIAL FOR FOG/STRATUS DEVELOPMENT OVERNIGHT. KSAV ONCE
AGAIN TOOK A DIRECT HIT FROM A THUNDERSTORM THIS AFTERNOON...SO
THE PROBABILITY IS HIGHEST THERE. GUIDANCE FAVORS IFR CONDITIONS
FOR A FEW HOURS...AND SINCE THEY ALSO HAD IT YESTERDAY IT SEEMS
LIKE A REASONABLE OUTCOME. I HAVE GONE WITH PREVAILING MVFR CIGS
STARTING AT 08Z WITH A TEMPO TILL 12Z FOR IFT CIGS. EVEN THOUGH
SURFACE WINDS WILL LIKELY GO CALM...THERE IS ENOUGH FLOW IN THE
LOWEST FEW HUNDRED FEET TO LIKELY FAVOR STRATUS OVER FOG. THE
PROBABILITY AT KCHS IS MUCH LOWER...AND I HAVE GONE WITH A PERIOD
OF JUST GROUND FOG THERE.

ANOTHER ROUND OF AFTERNOON/EVENING THUNDERSTORMS IS EXPECTED ON
WEDNESDAY. I HAVE ADDED A PROB30 GROUP TO BOTH SITES BETWEEN 19-23Z.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
ON THE EAST SIDE OF BROAD LOW PRESSURE. SEA BREEZE ENHANCEMENT
COULD SUPPORT LOCAL WINDS AS HIGH AS 15-20 KT THIS AFTERNOON/EARLY
EVENING...ESPECIALLY ON CHARLESTON HARBOR. OTHERWISE...WINDS OF 15
KTS OR LESS ARE EXPECTED. MAINTAINED SEAS FROM 2-4 FT WITHIN 20 NM
TO 4 FT 20-60 NM.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE WEEKEND...
WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER WINDS AND
LARGER SEAS FRIDAY THROUGH SUNDAY. SMALL CRAFT ADVISORIES SEEM
ALMOST A CERTAINTY DURING THAT TIME.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

NEAR TERM...SPR/BSH
SHORT TERM...JRL
LONG TERM...
AVIATION...BSH
MARINE...JRL/SPR

000
FXUS62 KFFC 152315 AAA
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
715 PM EDT TUE MAY 15 2012

.PREV DISCUSSION... /ISSUED 216 PM EDT TUE MAY 15 2012/

SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
A LARGE POSITIVELY TILTED TROUGH WAS LOCATED FROM OHIO SOUTH INTO
SOUTHERN TEXAS. THIS TROUGH HAS BEEN SLOWLY MOVING EAST WITH TIME.
WEAK SHORTWAVES HAVE BEEN TRANSVERSING THROUGH THE FLOW AND AIDING
IN SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN US. AT THE SURFACE
A STATIONARY FRONT WAS LOCATED ACROSS SOUTHERN GEORGIA. MODEL
SOUNDINGS AND CAPE VALUES TODAY SUGGEST THAT THUNDERSTORMS...AND
EVEN SOME STRONG THUNDERSTORMS ARE POSSIBLE TODAY. MODEL MUCAPE
VALUES RANGE FROM 2000 TO ALMOST 3000 J/KG ACROSS THE CWA TODAY.
WITH A BETTER DISTRIBUTION OF CAPE IN THE SOUNDING
TODAY...STRONGER UPDRAFTS SEEM POSSIBLE THIS AFTERNOON WITH ANY
THUNDERSTORMS THAT DEVELOP.

OVERNIGHT THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH.
WEDNESDAY...LOOKS LIKE THERE IS A CHANCE OF SHOWERS AND
THUNDERSTORMS AGAIN.  SOME OF THE HI-RES MODELS ARE INDICATING MORE
WIDESPREAD COVERAGE AND STRONGER STORMS ON WEDNESDAY.  THESE STORMS
SHOULD ALSO BE LIKE THE TYPICAL SUMMERTIME THUNDERSTORMS.  ON
THURSDAY WE SHOULD SEE ANOTHER CHANCE OF THUNDERSTORMS ALONG THE
STALLED OUT FRONTAL BOUNDARY ACROSS SOUTHERN GEORGIA.

TEMPERATURES WERE A BLEND OF THE MAV AND MET. NO OTHER TWEAKS WERE
MADE TO THEM.

GIBBS

LONG TERM /FRIDAY THROUGH TUESDAY/...
UNCERTAINTY CONTINUES FOR THE LONG TERM WITH THE UPPER TROUGH
HOLDING OVER THE CWA. THEREFORE WILL MAKE NO CHANGES TO THE
CURRENT LONG TERM. SEE THE PREVIOUS LONG TERM DISCUSSION BELOW...

/ISSUED 411 AM EDT TUE MAY 15 2012/
LATEST GFS RUN A TAF SLOWER THAN PREVIOUS WITH AXIS OF UPPER TROF
SWINGING EAST OF THE COUNTY WARNING AREA AND UPPER RIDGE BUILDING
IN BEHIND IT. GFS NOW INDICATING A WEAK BOUNDARY APPROACHING THE
TENNESSEE VALLEY THURSDAY WITH SOME DEEPER MOISTURE SPREADING INTO
EXTREME NORTHERN COUNTIES. MODELS HOLD ON TO REMNANTS OF WEAK
BOUNDARY SOMEWHERE NEAR THE TN/WRN NC BORDER THURSDAY NIGHT BEFORE
WASHING IT FRIDAY AS HIGH PRESSURE WEDGES DOWN THE APPALACHIANS
AND REMAIN DOMINANT OVER OUR AREA THROUGH THE WEEKEND. ECMWF MOST
AGGRESSIVE WITH SHOWING A WEAK COASTAL LOW FORMING NEAR THE
SOUTHEAST COAST OVER THE WEEKEND...BUT BOTH ECMWF AND GFS SIMILAR
WITH KEEPING BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE EAST
AND SOUTH OF OUR AREA. MAY BE GETTING INTO BETTER CHANCES FOR
PRECIP MONDAY/TUESDAY WITH EXTENDED PROGS INDICATING A FRONTAL
BOUNDARY DRIFTING SOUTHEAST FROM THE OHIO/TENNESSEE VALLEY REGION.

49

&&

.AVIATION...
00Z UPDATE...
MAINLY VFR CONDITIONS OVERNIGHT. AREA MAINLY SHOWERS APPROACHING
ATL AREA TAFS SHOULD PROVIDE ONLY BRIEF LOWER VFR CONDITIONS.
PATCHY MVFR VSBYS LATE NIGHT-EARLY MORNING. SURFACE WINDS LIGHT WNW
BECOMING CALM FOR MANY AREAS. BDL

//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          60  85  59  84 /  30  20  20  10
ATLANTA         62  83  61  83 /  20  10  10  10
BLAIRSVILLE     54  79  53  79 /  30  10  10  20
CARTERSVILLE    57  84  56  84 /  20  10  10  20
COLUMBUS        63  86  62  86 /  20  10  10  10
GAINESVILLE     60  82  59  81 /  30  10  10  20
MACON           61  86  60  86 /  30  30  20  20
ROME            57  84  55  85 /  20  10   5  10
PEACHTREE CITY  58  83  56  84 /  20  10  10  10
VIDALIA         67  88  65  87 /  30  30  20  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...LYNN
LONG TERM....DEESE/BAKER
AVIATION...LYNN

000
FXUS62 KCHS 152302
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
702 PM EDT TUE MAY 15 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
DISCONTINUED SEVERE THUNDERSTORM WATCH FOR NEARSHORE COASTAL
WATERS OUTSIDE CHARLESTON HARBOR...AND ADJUSTED POPS THROUGH MID
EVENING. ONGOING BOUNDARY INTERACTIONS WILL SUPPORT AN ISOLATED
SEVERE THREAT FOR THE NEXT 1-2 HOURS AWAY FROM THE COAST.

PER DIURNAL TRENDS...THUNDERSTORMS WILL DECREASE IN COVERAGE AND
INTENSITY TONIGHT...AND THE REGION SHOULD BECOME MAINLY
PRECIPITATION FREE OVERNIGHT.

OVERNIGHT INTO EARLY WEDNESDAY...AREAS OF STRATUS AND/OR FOG COULD
DEVELOP WHERE HEAVY RAIN OCCURS THIS AFTERNOON/EVENING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
ALTHOUGH A BROAD UPPER TROUGH WILL PERSIST OVER THE SOUTHEAST UNITED
STATES WEDNESDAY THROUGH FRIDAY...THE PRIMARY UPPER LOW WILL MOVE
THROUGH THE FORECAST AREA THURSDAY AND OFFSHORE BY FRIDAY. QUITE A
BIT OF SHORTWAVE ENERGY LIFTING OUT OF THE NORTHEAST GULF OF MEXICO
WEDNESDAY AND THURSDAY...COINCIDENT WITH RELATIVELY MOIST BOUNDARY
LAYER AND DIURNAL HEATING...SHOULD RESULT IN GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOONS. A COLD
FRONT IS PROGGED TO DROP INTO THE NORTHERN HALF OF THE AREA ON
THURSDAY WHICH WILL PROVIDE AN ADDITIONAL FOCUS FOR CONVECTION.
SEVERE THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY OR THURSDAY DUE
TO THE ABUNDANCE OF FORCING MECHANISMS AND REASONABLY HIGH
CONVECTIVE INDICES.

THE FRONT WILL DROP THROUGH THURSDAY NIGHT WITH HIGH PRESSURE
BUILDING DOWN THE COAST ON FRIDAY. CONVECTION WILL STILL BE POSSIBLE
OVER OUR FAR SOUTHERN GA ZONES AS THE FRONT STALLS ALONG THE
ALTAMAHA RIVER.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
THE PROBABILITY FOR THUNDERSTORM IMPACTS AT TERMINALS IS LOWERING
WITH TIME BUT WILL CONTINUE TO MONITOR UPSTREAM CONVECTIVE TRENDS.
EXPECT AMENDMENTS AS NECESSARY TO ADDRESS NEAR TERM CONVECTIVE
TRENDS. OTHERWISE...MAINLY VFR THROUGH AT LEAST THIS EVENING.
THEN...LOW CHANCE OF MVFR OR LOWER CONDITIONS LATE TONIGHT INTO
EARLY WEDNESDAY IN A SHOWER...STRATUS AND/OR FOG...ESPECIALLY WHERE
THUNDERSTORMS OCCURRED AT KSAV. THUNDERSTORMS ARE EXPECTED TO
REDEVELOP WEDNESDAY...BUT MAINLY 18Z OR LATER.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
ON THE EAST SIDE OF BROAD LOW PRESSURE. SEA BREEZE ENHANCEMENT
COULD SUPPORT LOCAL WINDS AS HIGH AS 15-20 KT THIS AFTERNOON/EARLY
EVENING...ESPECIALLY ON CHARLESTON HARBOR. OTHERWISE...WINDS OF 15
KTS OR LESS ARE EXPECTED. MAINTAINED SEAS FROM 2-4 FT WITHIN 20 NM
TO 4 FT 20-60 NM.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE WEEKEND...
WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER WINDS AND
LARGER SEAS FRIDAY THROUGH SUNDAY. SMALL CRAFT ADVISORIES SEEM
ALMOST A CERTAINTY DURING THAT TIME.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...JRL
LONG TERM...
AVIATION...SPR
MARINE...JRL/SPR

000
FXUS62 KCAE 152226
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
626 PM EDT TUE MAY 15 2012

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY ACROSS THE REGION WILL PROVIDE A FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING. THE FRONT WILL
SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE INCREASED CHANCES
OF THUNDERSTORMS ACROSS THE EASTERN MIDLANDS ON WEDNESDAY BEFORE
SHIFTING TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD INTO THE
REGION THURSDAY AND PROVIDE DRY WEATHER THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 9 PM.

CONVECTION CURRENTLY CROSSING THE MIDLANDS. LIFTED INDEX UP TO
MINUS 6 AND CAPES 1500-2500 J/KG. ISOLATED SEVERE STORMS WITH HAIL
AND DAMAGING WINDS. LOCAL 4 KM WRF MODEL GIVING HIGHEST CHANCE OF
CONVECTION INTO EVENING. REDUCED POP TO 20 PERCENT OR LESS AFTER
MIDNIGHT WITH LOSS OF HEATING.

THERE MAY BE SOME PATCHY FOG AFTER MIDNIGHT AS WELL BUT LEFT OUT
FOR TIME BEING AS SHOWERS MAY LINGER WELL AFTER MIDNIGHT WITH SOME
CLOUDINESS NOT ALLOWING WIDESPREAD FOG LIKE THIS MORNING. WENT
ABOVE GUIDANCE LOWS 1-2 DEGREES AS PREVIOUS RUNS HAVE BEEN A BIT
COOL.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
LOW PRESSURE WILL BE TRACKING FROM NEW ENGLAND INTO THE FAR EASTERN
CANADIAN PROVINCES AS A WEAK FRONTAL BOUNDARY SLOWLY CROSSES THE
FORECAST AREA. ON WEDNESDAY THE FRONT WILL BE OVER THE UPSTATE WITH
ANOTHER UNSTABLE DAY FOR CONVECTIVE ACTIVITY. WITH AROUND 2000 J/KG
CAPE AND LI/S AROUND -5 EXPECT ANOTHER AFTERNOON AND EVENING WITH
SCATTERED SHOWERS AND THUNDERSTORMS. MODELS INDICATE THE BEST
INSTABILITY OVER THE EASTERN MIDLANDS AND...WITH THE POSITION OF THE
FRONT AND HIGHER MOISTURE IN THE EASTERN MIDLANDS...AGREE HIGHEST
POPS TO START IN THAT AREA. WILL EXPAND POPS TO THE REMAINDER OF THE
AREA AS PLENTIFUL INSTABILITY COMBINING WITH OUTFLOWS WILL LIKELY
SPUR ADDITIONAL ACTIVITY. SPC CONTINUES TO KEEP THE REGION IN
GENERAL THUNDER WHICH CURRENTLY SEEMS APPROPRIATE. MAIN THREAT OF
SEVERE ON WEDNESDAY AFTERNOON WILL BE HAIL WITH A LOWER CHANCE FOR
WIND GUSTS. CONVECTIVE ACTIVITY WILL DIMINISH WITH THE LOSS OF
HEATING WEDNESDAY EVENING...HOWEVER WITH OUTFLOW BOUNDARIES REMAINING
OVER THE FORECAST AREA BELIEVE CONVECTION WILL LINGER INTO THE LATE
EVENING/EARLY OVERNIGHT HOURS. AFTERNOON HIGH TEMPERATURES
WEDNESDAY WILL GENERALLY BE IN THE MIDDLE 80S. WITH SOME LINGERING
CLOUDS AND PATCHY FOG EXPECT OVERNIGHT LOWS WEDNESDAY NIGHT IN THE
LOWER 60S.

ON THURSDAY THE FRONT WILL BE OVER THE EASTERN MIDLANDS DURING THE
AFTERNOON AND TRACKING OFFSHORE DURING THE EVENING. INSTABILITY WILL
BE LESS THAN WEDNESDAY...HOWEVER THERE WILL STILL BE ENOUGH TO
INITIATE CONVECTION. BEST INSTABILITY WILL BE CLOSER TO THE FRONT SO
WILL AGAIN INCREASE POPS CLOSEST TO THE FRONT THEN EXPAND A BIT
WESTWARD AS OUTFLOWS TRIGGER SOME ADDITIONAL CONVECTION. SEVERE
THREAT WILL AGAIN BE FROM HAIL WITH LOWER POTENTIAL FOR DAMAGING
WINDS. HIGH TEMPERATURES THURSDAY AFTERNOON WILL GENERALLY BE IN THE
LOWER 80S. CONVECTION WILL DISSIPATE WITH LOSS OF HEATING AND THE
FRONT EDGING OFFSHORE. EXPECT SOME CONVECTION INTO THE EVENING HOURS
AND WITH THE FRONT MOVING OFFSHORE EXPECT CONVECTION TO END BEFORE
THE OVERNIGHT HOURS. LOW TEMPERATURES THURSDAY NIGHT WILL BE A FEW
DEGREES COOLER BEHIND THE FRONT WITH LOWS IN THE UPPER 50S TO LOWER
60S.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME
TYPICAL TIMING AND INTENSITY DIFFERENCES FOR SUNDAY AND MONDAY.
UPPER LEVEL TROUGH WILL EXIT THE REGION EARLY FRIDAY AS THE UPPER
LEVEL RIDGE BUILDS BACK IN. THIS WILL LEAVE A STATIONARY FRONT
ALONG THE COAST TO JUST SOUTH OF THE AREA. MODELS DIFFER ON THE
LOCATION OF THE FRONT...HOWEVER WITH HIGH PRESSURE DOMINATING THE
SURFACE EXPECT MUCH OF THE CONVECTIVE POTENTIAL TO BE SUPPRESSED
THROUGH THE WEEKEND. AS THE HIGH MOVES OFFSHORE MONDAY THE CHANCE
OF THUNDERSTORMS WILL RETURN. MODELS CONTINUE TO HAVE SIGNIFICANT
RUN TO RUN CHANGES ASSOCIATED WITH A LOW WHICH DEVELOPS ALONG THE
COAST. AS A RESULT HAVE REMAINED PESSIMISTIC CONCERNING THIS
FEATURE. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
UPPER TROUGH STILL TO THE WEST BRINGING MOISTURE TO AREA.
WEAK FRONTAL BOUNDARY ACROSS THE REGION AND LEFT OVER OUTFLOW
BOUNDARIES FROM CONVECTIVE ACTIVITY SHOULD PROVIDE A FOCUS FOR
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. MAINLY VFR
CONDITIONS BUT BRIEF IFR-MVFR CONDITIONS ARE POSSIBLE IN CONVECTIVE
ACTIVITY. DECIDED NOT TO INCLUDE IN TAFS SITES DUE TO UNCERTAINTY
AS TO TIMING AND COVERAGE. ACTIVITY IS EXPECTED TO TAPER OFF 03Z-04Z
TIME FRAME BUT MAY LINGER NORTH AND EAST OF TAF SITES. AFTER
MIDNIGHT WITH PLENTY OF MOISTURE AND LEFT OVER CLOUDS...NO AS MUCH
FOG EXPECTED BUT STRATUS WILL PROBABLY DEVELOP AGAIN. EXPECT IFR
CEILINGS TO DEVELOP BEFORE DAYBREAK WEDNESDAY. THE UPPER TROUGH
SHOULD HAVE SHIFTED EASTWARD BY WEDNESDAY BUT THERE WILL STILL BE
ENOUGH MOISTURE AND INSTABILITY FOR SOME AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. WILL GO VFR BUT LOWER CONDITIONS MAY
OCCUR IN CONVECTIVE ACTIVITY.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS ARE
EXPECTED WEDNESDAY NIGHT THROUGH SUNDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KCHS 152130
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
530 PM EDT TUE MAY 15 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
UPDATED FORECASTS TO FINE TUNE POPS AND OTHER FORECAST PARAMETERS
THROUGH EARLY EVENING

OUTFLOW FROM ONGOING CLUSTERS OF THUNDERSTORMS WILL CONTINUE TO
PROMOTE SCATTERED TO NUMEROUS THUNDERSTORMS INTO EARLY EVENING.
BOUNDARY INTERACTIONS AND A FAVORABLE THERMODYNAMIC ENVIRONMENT
WILL SUPPORT OCCASIONAL SEVERE THUNDERSTORMS WITH LARGE HAIL AND
DAMAGING MICROBURSTS. THUS...SEVERE THUNDERSTORM WATCH REMAINS IN
EFFECT IN ADDITION TO BRIEF/PULSE SEVER EVENTS... ISOLATED
THUNDERSTORM CLUSTERS COULD PERSIST SUCH AS SEVERE THUNDERSTORMS
THAT PRODUCED DAMAGING WINDS AND UP TO GOLFBALL SIZE HAIL WHICH
IMPACTED AREAS ALONG I-95 FROM MCINTOSH COUNTY...THROUGH THE
SAVANNAH AREA AND INTO JASPER COUNTY.

OF INTEREST...THE MOST ACTIVE REGIME HAS REMAINED NORTH/WEST OF THE
CHARLESTON TRI-COUNTY REGION...AND THERE REMAINS SOME QUESTION
ABOUT WHETHER ANY THUNDERSTORMS WILL PUSH INTO THIS AREA.
MAINTAINED ONGOING SLIGHT CHANCE TO CHANCE POPS THROUGH EARLY
EVENING AS UPSTREAM CONVECTION COULD STILL SPILL BACK TOWARD THE
COAST.

PER DIURNAL TRENDS...THUNDERSTORMS WILL DECREASE IN COVERAGE AND
INTENSITY TONIGHT...AND THE REGION SHOULD BECOME MAINLY
PRECIPITATION FREE OVERNIGHT.

OVERNIGHT INTO EARLY WEDNESDAY...AREAS OF STRATUS AND/OR FOG COULD
DEVELOP WHERE HEAVY RAIN OCCURS THIS AFTERNOON/EVENING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
ALTHOUGH A BROAD UPPER TROUGH WILL PERSIST OVER THE SOUTHEAST UNITED
STATES WEDNESDAY THROUGH FRIDAY...THE PRIMARY UPPER LOW WILL MOVE
THROUGH THE FORECAST AREA THURSDAY AND OFFSHORE BY FRIDAY. QUITE A
BIT OF SHORTWAVE ENERGY LIFTING OUT OF THE NORTHEAST GULF OF MEXICO
WEDNESDAY AND THURSDAY...COINCIDENT WITH RELATIVELY MOIST BOUNDARY
LAYER AND DIURNAL HEATING...SHOULD RESULT IN GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOONS. A COLD
FRONT IS PROGGED TO DROP INTO THE NORTHERN HALF OF THE AREA ON
THURSDAY WHICH WILL PROVIDE AN ADDITIONAL FOCUS FOR CONVECTION.
SEVERE THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY OR THURSDAY DUE
TO THE ABUNDANCE OF FORCING MECHANISMS AND REASONABLY HIGH
CONVECTIVE INDICES.

THE FRONT WILL DROP THROUGH THURSDAY NIGHT WITH HIGH PRESSURE
BUILDING DOWN THE COAST ON FRIDAY. CONVECTION WILL STILL BE POSSIBLE
OVER OUR FAR SOUTHERN GA ZONES AS THE FRONT STALLS ALONG THE
ALTAMAHA RIVER.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
ADDITIONAL THUNDERSTORMS COULD IMPACT KSAV INTO EARLY
EVENING. THE PROBABILITY FOR THUNDERSTORMS IS LOWER AT KCHS BUT
UPSTREAM THUNDERSTORMS COULD STILL PUSH INTO THAT AREA. EXPECT
AMENDMENTS TO ADDRESS NEAR TERM CONVECTIVE TRENDS. OUTSIDE
ANY THUNDERSTORMS..MAINLY VFR THROUGH AT LEAST THIS EVENING.
THEN...LOW CHANCE OF MVFR OR LOWER CONDITIONS LATE TONIGHT INTO
EARLY WEDNESDAY IN A SHOWER...STRATUS AND/OR FOG. THUNDERSTORMS
ARE EXPECTED TO REDEVELOP WEDNESDAY...BUT MAINLY 18Z OR LATER.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
THUNDERSTORMS COULD LOCALLY ALTER WINDS CLOSE TO THE COAST INTO
THIS EVENING. OTHERWISE...WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SCA
CRITERIA THROUGH TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA
OF S TO SW FLOW ON THE EAST SIDE OF BROAD LOW PRESSURE. SEA BREEZE
ENHANCEMENT COULD SUPPORT LOCAL WINDS AS HIGH AS 15-20 KT THIS
AFTERNOON/EARLY EVENING...ESPECIALLY ON CHARLESTON HARBOR.
OTHERWISE...WINDS OF 15 KTS OR LESS ARE EXPECTED. MAINTAINED SEAS
FROM 2-4 FT WITHIN 20 NM TO 4 FT 20-60 NM.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE WEEKEND...
WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER WINDS AND
LARGER SEAS FRIDAY THROUGH SUNDAY. SMALL CRAFT ADVISORIES SEEM
ALMOST A CERTAINTY DURING THAT TIME.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...JRL
LONG TERM...
AVIATION...SPR
MARINE...JRL/SPR

000
FXUS62 KCHS 151936
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
336 PM EDT TUE MAY 15 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
PRIMARY FORECAST ATTENTION CENTERS ON CONVECTION/SEVERE POTENTIAL
INTO THIS EVENING.

THE REGION REMAINS BENEATH A BROAD/DEEP LAYER CYCLONIC FLOW REGIME
WHICH WILL BE PUNCTUATED BY NUMEROUS/EMBEDDED MESOSCALE
BOUNDARIES.

IN THE NEAR TERM...THUNDERSTORMS WILL INCREASE IN COVERAGE BY LATE
AFTERNOON AS MID LEVEL DRY AIR LIFTS NORTH OF THE FORECAST AREA...
THE SEA BREEZE GRADUALLY PUSHES INLAND AND ONGOING CONVECTION
PRODUCES OUTFLOW BOUNDARIES. THEN...SCATTERED TO NUMEROUS
MULTICELL THUNDERSTORMS WILL DEVELOP DISSIPATE INTO THIS EVENING.

SBCAPES 2500-3000 J/KG....DOWNDRAFT CAPES EXCEEDING 1000
J/KG AND WET BULB ZERO HEIGHTS AROUND 10 KFT AGL WILL SUPPORT
OCCASIONAL PULSE SEVERE THUNDERSTORMS WITH DAMAGING MICROBURSTS
AND LARGE HAIL...ESPECIALLY WHERE THUNDERSTORM/MESOSCALE BOUNDARY
INTERACTIONS OCCUR. DUE TO THE SYNOPTIC SCALE CYCLONIC FLOW REGIME
AND THESE THERMODYNAMIC PARAMETERS...SEVERE THUNDERSTORM WATCH 278
IS IN EFFECT UNTIL 9 PM.

PER DIURNAL TRENDS...THUNDERSTORMS WILL DECREASE IN COVERAGE AND
INTENSITY TONIGHT...AND THE REGION SHOULD BECOME MAINLY
PRECIPITATION FREE OVERNIGHT.

OVERNIGHT INTO EARLY WEDNESDAY...AREAS OF STRATUS AND/OR FOG COULD
DEVELOP WHERE HEAVY RAIN OCCURS THIS AFTERNOON/EVENING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
ALTHOUGH A BROAD UPPER TROUGH WILL PERSIST OVER THE SOUTHEAST UNITED
STATES WEDNESDAY THROUGH FRIDAY...THE PRIMARY UPPER LOW WILL MOVE
THROUGH THE FORECAST AREA THURSDAY AND OFFSHORE BY FRIDAY. QUITE A
BIT OF SHORTWAVE ENERGY LIFTING OUT OF THE NORTHEAST GULF OF MEXICO
WEDNESDAY AND THURSDAY...COINCIDENT WITH RELATIVELY MOIST BOUNDARY
LAYER AND DIURNAL HEATING...SHOULD RESULT IN GOOD COVERAGE OF
SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE AFTERNOONS. A COLD
FRONT IS PROGGED TO DROP INTO THE NORTHERN HALF OF THE AREA ON
THURSDAY WHICH WILL PROVIDE AN ADDITIONAL FOCUS FOR CONVECTION.
SEVERE THUNDERSTORMS CANNOT BE RULED OUT WEDNESDAY OR THURSDAY DUE
TO THE ABUNDANCE OF FORCING MECHANISMS AND REASONABLY HIGH
CONVECTIVE INDICES.

THE FRONT WILL DROP THROUGH THURSDAY NIGHT WITH HIGH PRESSURE
BUILDING DOWN THE COAST ON FRIDAY. CONVECTION WILL STILL BE POSSIBLE
OVER OUR FAR SOUTHERN GA ZONES AS THE FRONT STALLS ALONG THE
ALTAMAHA RIVER.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
MAINLY VFR. HOWEVER...THUNDERSTORMS SHOULD IMPACT BOTH
TERMINALS...ESPECIALLY KSAV...THIS AFTERNOON INTO EARLY EVENING.
EXPECT AMENDMENTS TO ADDRESS NEAR TERM CONVECTIVE TRENDS.
THEN...LOW CHANCE OF MVFR OR LOWER CONDITIONS LATE TONIGHT INTO
EARLY WEDNESDAY IN A SHOWER...STRATUS AND/OR FOG. THUNDERSTORMS
ARE EXPECTED TO REDEVELOP WEDNESDAY...BUT MAINLY 18Z OR LATER.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
THUNDERSTORMS COULD LOCALLY ALTER WINDS THIS AFTERNOON INTO TONIGHT.
OTHERWISE...WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
ON THE EAST SIDE OF BROAD LOW PRESSURE. SEA BREEZE ENHANCEMENT
COULD SUPPORT LOCAL WINDS AS HIGH AS 15-20 KT THIS AFTERNOON/EARLY
EVENING...ESPECIALLY ON CHARLESTON HARBOR. OTHERWISE...WINDS OF
15 KTS OR LESS ARE EXPECTED. MAINTAINED SEAS FROM 2-4 FT WITHIN
20 NM TO 4 FT 20-60 NM.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE WEEKEND...
WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER WINDS AND
LARGER SEAS FRIDAY THROUGH SUNDAY. SMALL CRAFT ADVISORIES SEEM
ALMOST A CERTAINTY DURING THAT TIME.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...JRL
LONG TERM...
AVIATION...SPR
MARINE...JRL/SPR

000
FXUS62 KCAE 151841
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
241 PM EDT TUE MAY 15 2012

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY ACROSS THE REGION WILL PROVIDE A FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND THIS EVENING.
THE FRONT WILL SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE
INCREASED CHANCES OF RAIN ACROSS THE EASTERN MIDLANDS ON WEDNESDAY
BEFORE SHIFTING TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD
INTO THE REGION THURSDAY AND PROVIDE DRY WEATHER THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...A WEAK FRONTAL BOUNDARY AND LEFT OVER OUTFLOW
BOUNDARIES WILL PROVIDE A FOCUS FOR SHOWER AND THUNDERSTORM
DEVELOPMENT. SPC HAS AREA IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING HOURS. THE LATEST RAP SOUNDING FOR
LATE THIS AFTERNOON CONFIRMS THAT THE ATMOSPHERE SHOULD BE UNSTABLE
ENOUGH TO PRODUCE STRONG TO POTENTIALLY SEVERE STORMS. RAP LIS -5
...CAPES OVER 2000 J/KG...TOTALS OVER 50. NAM SOUNDING GIVES
CONVECTIVE TEMPERATURES 82-84 DEGREE THIS AFTERNOON. TEMPERATURES
SHOULD RISE INTO THE LOWER TO MIDDLE 80S DURING THE AFTERNOON.
THIS IS EXPECTED TO ENHANCE SHOWERS AND THUNDERSTORMS...ESPECIALLY
LATE THIS AFTERNOON. WILL START WITH A 20-30 PERCENT CHANCE THIS
AFTERNOON. LOCAL WRF SHOWS INCREASING TREND...ESPECIALLY LATER
THIS AFTERNOON. JUST ISSUED SEVERE THUNDERSTORM WATCH IN EFFECT.

TONIGHT...BEST CHANCES OF SHOWERS AND THUNDERSTORMS WITH CHANCES
INCREASING TO 40-50 PERCENT. AGREE WITH LOCAL 4 KM WRF MODEL GIVING
HIGHEST CHANCES IN THE EVENING. AS TEMPERATURES DROP BY MIDNIGHT...
DECIDED TO GO JUST 20 PERCENT CHANCE REST OF NIGHT AFTER MIDNIGHT.
THERE MAY BE SOME PATCHY FOG AFTER MIDNIGHT AS WELL BUT LEFT OUT
FOR TIME BEING AS SHOWERS MAY LINGER WELL AFTER MIDNIGHT WITH SOME
CLOUDINESS NOT ALLOWING WIDESPREAD FOG LIKE THIS MORNING. WENT ABOVE
GUIDANCE LOWS 1-2 DEGREES AS PREVIOUS RUNS HAVE BEEN A BIT COOL.
SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 9 PM.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
LOW PRESSURE WILL BE TRACKING FROM NEW ENGLAND INTO THE FAR EASTERN
CANADIAN PROVINCES AS A WEAK FRONTAL BOUNDARY SLOWLY CROSSES THE
FORECAST AREA. ON WEDNESDAY THE FRONT WILL BE OVER THE UPSTATE WITH
ANOTHER UNSTABLE DAY FOR CONVECTIVE ACTIVITY. WITH AROUND 2000 J/KG
CAPE AND LI/S AROUND -5 EXPECT ANOTHER AFTERNOON AND EVENING WITH
SCATTERED SHOWERS AND THUNDERSTORMS. MODELS INDICATE THE BEST
INSTABILITY OVER THE EASTERN MIDLANDS AND...WITH THE POSITION OF THE
FRONT AND HIGHER MOISTURE IN THE EASTERN MIDLANDS...AGREE HIGHEST
POPS TO START IN THAT AREA. WILL EXPAND POPS TO THE REMAINDER OF THE
AREA AS PLENTIFUL INSTABILITY COMBINING WITH OUTFLOWS WILL LIKELY
SPUR ADDITIONAL ACTIVITY. SPC CONTINUES TO KEEP THE REGION IN
GENERAL THUNDER WHICH CURRENTLY SEEMS APPROPRIATE. MAIN THREAT OF
SEVERE ON WEDNESDAY AFTERNOON WILL BE HAIL WITH A LOWER CHANCE FOR
WIND GUSTS. CONVECTIVE ACTIVITY WILL DIMINISH WITH THE LOSS OF
HEATING WEDNESDAY EVENING...HOWEVER WITH OUTFLOW BOUNDARIES REMAINING
OVER THE FORECAST AREA BELIEVE CONVECTION WILL LINGER INTO THE LATE
EVENING/EARLY OVERNIGHT HOURS. AFTERNOON HIGH TEMPERATURES
WEDNESDAY WILL GENERALLY BE IN THE MIDDLE 80S. WITH SOME LINGERING
CLOUDS AND PATCHY FOG EXPECT OVERNIGHT LOWS WEDNESDAY NIGHT IN THE
LOWER 60S.

ON THURSDAY THE FRONT WILL BE OVER THE EASTERN MIDLANDS DURING THE
AFTERNOON AND TRACKING OFFSHORE DURING THE EVENING. INSTABILITY WILL
BE LESS THAN WEDNESDAY...HOWEVER THERE WILL STILL BE ENOUGH TO
INITIATE CONVECTION. BEST INSTABILITY WILL BE CLOSER TO THE FRONT SO
WILL AGAIN INCREASE POPS CLOSEST TO THE FRONT THEN EXPAND A BIT
WESTWARD AS OUTFLOWS TRIGGER SOME ADDITIONAL CONVECTION. SEVERE
THREAT WILL AGAIN BE FROM HAIL WITH LOWER POTENTIAL FOR DAMAGING
WINDS. HIGH TEMPERATURES THURSDAY AFTERNOON WILL GENERALLY BE IN THE
LOWER 80S. CONVECTION WILL DISSIPATE WITH LOSS OF HEATING AND THE
FRONT EDGING OFFSHORE. EXPECT SOME CONVECTION INTO THE EVENING HOURS
AND WITH THE FRONT MOVING OFFSHORE EXPECT CONVECTION TO END BEFORE
THE OVERNIGHT HOURS. LOW TEMPERATURES THURSDAY NIGHT WILL BE A FEW
DEGREES COOLER BEHIND THE FRONT WITH LOWS IN THE UPPER 50S TO LOWER
60S.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME
TYPICAL TIMING AND INTENSITY DIFFERENCES FOR SUNDAY AND MONDAY.
UPPER LEVEL TROUGH WILL EXIT THE REGION EARLY FRIDAY AS THE UPPER
LEVEL RIDGE BUILDS BACK IN. THIS WILL LEAVE A STATIONARY FRONT
ALONG THE COAST TO JUST SOUTH OF THE AREA. MODELS DIFFER ON THE
LOCATION OF THE FRONT...HOWEVER WITH HIGH PRESSURE DOMINATING THE
SURFACE EXPECT MUCH OF THE CONVECTIVE POTENTIAL TO BE SUPPRESSED
THROUGH THE WEEKEND. AS THE HIGH MOVES OFFSHORE MONDAY THE CHANCE
OF THUNDERSTORMS WILL RETURN. MODELS CONTINUE TO HAVE SIGNIFICANT
RUN TO RUN CHANGES ASSOCIATED WITH A LOW WHICH DEVELOPS ALONG THE
COAST. AS A RESULT HAVE REMAINED PESSIMISTIC CONCERNING THIS
FEATURE. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
UPPER TROUGH STILL TO THE WEST BRINGING MOISTURE TO AREA.
WEAK FRONTAL BOUNDARY ACROSS THE REGION AND LEFT OVER OUTFLOW
BOUNDARIES FROM CONVECTIVE ACTIVITY SHOULD PROVIDE A FOCUS FOR
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. MAINLY VFR
CONDITIONS BUT BRIEF IFR-MVFR CONDITIONS ARE POSSIBLE IN CONVECTIVE
ACTIVITY. DECIDED NOT TO INCLUDE IN TAFS SITES DUE TO UNCERTAINTY
AS TO TIMING AND COVERAGE. ACTIVITY IS EXPECTED TO TAPER OFF 03Z-04Z
TIME FRAME BUT MAY LINGER NORTH AND EAST OF TAF SITES. AFTER
MIDNIGHT WITH PLENTY OF MOISTURE AND LEFT OVER CLOUDS...NO AS MUCH
FOG EXPECTED BUT STRATUS WILL PROBABLY DEVELOP AGAIN. EXPECT IFR
CEILINGS TO DEVELOP BEFORE DAYBREAK WEDNESDAY. THE UPPER TROUGH
SHOULD HAVE SHIFTED EASTWARD BY WEDNESDAY BUT THERE WILL STILL BE
ENOUGH MOISTURE AND INSTABILITY FOR SOME AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. WILL GO VFR BUT LOWER CONDITIONS MAY
OCCUR IN CONVECTIVE ACTIVITY.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS ARE
EXPECTED WEDNESDAY NIGHT THROUGH SUNDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KFFC 151816
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
216 PM EDT TUE MAY 15 2012

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
A LARGE POSITIVELY TILTED TROUGH WAS LOCATED FROM OHIO SOUTH INTO
SOUTHERN TEXAS. THIS TROUGH HAS BEEN SLOWLY MOVING EAST WITH TIME.
WEAK SHORTWAVES HAVE BEEN TRANSVERSING THROUGH THE FLOW AND AIDING
IN SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN US. AT THE SURFACE
A STATIONARY FRONT WAS LOCATED ACROSS SOUTHERN GEORGIA. MODEL
SOUNDINGS AND CAPE VALUES TODAY SUGGEST THAT THUNDERSTORMS...AND
EVEN SOME STRONG THUNDERSTORMS ARE POSSIBLE TODAY. MODEL MUCAPE
VALUES RANGE FROM 2000 TO ALMOST 3000 J/KG ACROSS THE CWA TODAY.
WITH A BETTER DISTRIBUTION OF CAPE IN THE SOUNDING
TODAY...STRONGER UPDRAFTS SEEM POSSIBLE THIS AFTERNOON WITH ANY
THUNDERSTORMS THAT DEVELOP.

OVERNIGHT THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH.
WEDNESDAY...LOOKS LIKE THERE IS A CHANCE OF SHOWERS AND
THUNDERSTORMS AGAIN.  SOME OF THE HI-RES MODELS ARE INDICATING MORE
WIDESPREAD COVERAGE AND STRONGER STORMS ON WEDNESDAY.  THESE STORMS
SHOULD ALSO BE LIKE THE TYPICAL SUMMERTIME THUNDERSTORMS.  ON
THURSDAY WE SHOULD SEE ANOTHER CHANCE OF THUNDERSTORMS ALONG THE
STALLED OUT FRONTAL BOUNDARY ACROSS SOUTHERN GEORGIA.

TEMPERATURES WERE A BLEND OF THE MAV AND MET. NO OTHER TWEAKS WERE
MADE TO THEM.

GIBBS

.LONG TERM /FRIDAY THROUGH TUESDAY/...
UNCERTAINTY CONTINUES FOR THE LONG TERM WITH THE UPPER TROUGH
HOLDING OVER THE CWA. THEREFORE WILL MAKE NO CHANGES TO THE
CURRENT LONG TERM. SEE THE PREVIOUS LONG TERM DISCUSSION BELOW...

/ISSUED 411 AM EDT TUE MAY 15 2012/
LATEST GFS RUN A TAF SLOWER THAN PREVIOUS WITH AXIS OF UPPER TROF
SWINGING EAST OF THE COUNTY WARNING AREA AND UPPER RIDGE BUILDING
IN BEHIND IT. GFS NOW INDICATING A WEAK BOUNDARY APPROACHING THE
TENNESSEE VALLEY THURSDAY WITH SOME DEEPER MOISTURE SPREADING INTO
EXTREME NORTHERN COUNTIES. MODELS HOLD ON TO REMNANTS OF WEAK
BOUNDARY SOMEWHERE NEAR THE TN/WRN NC BORDER THURSDAY NIGHT BEFORE
WASHING IT FRIDAY AS HIGH PRESSURE WEDGES DOWN THE APPALACHIANS
AND REMAIN DOMINANT OVER OUR AREA THROUGH THE WEEKEND. ECMWF MOST
AGGRESSIVE WITH SHOWING A WEAK COASTAL LOW FORMING NEAR THE
SOUTHEAST COAST OVER THE WEEKEND...BUT BOTH ECMWF AND GFS SIMILAR
WITH KEEPING BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE EAST
AND SOUTH OF OUR AREA. MAY BE GETTING INTO BETTER CHANCES FOR
PRECIP MONDAY/TUESDAY WITH EXTENDED PROGS INDICATING A FRONTAL
BOUNDARY DRIFTING SOUTHEAST FROM THE OHIO/TENNESSEE VALLEY REGION.

49

&&

.AVIATION...
18Z UPDATE...
MAIN CONCERN FOR TODAY ARE THE CHANCES OF THUNDER. TODAYS SOUNDING
SUGGESTS THAT THUNDER IS MORE LIKELY TODAY THAN IT WAS YESTERDAY.
HAVE INCLUDED A TEMPO TO COVER CONVECTION LATER THIS AFTERNOON.
CURRENT TRENDS SUGGESTS THIS...HOWEVER...WE COULD SEE THUNDER
EARLIER AND THE TEMPO MAY NEED TO BE ADJUSTED. OTHERWISE EXPECT
VFR CONDITIONS THROUGH THE PERIOD.

//ATL CONFIDENCE...18Z UPDATE...
LOW CONFIDENCE ON THUNDER TODAY. HIGH CONFIDENCE ON ALL OTHER ELEMENTS.

GIBBS

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          60  85  59  84 /  30  20  20  10
ATLANTA         62  83  61  83 /  20  10  10  10
BLAIRSVILLE     54  79  53  79 /  30  10  10  20
CARTERSVILLE    57  84  56  84 /  20  10  10  20
COLUMBUS        63  86  62  86 /  20  10  10  10
GAINESVILLE     60  82  59  81 /  30  10  10  20
MACON           61  86  60  86 /  30  30  20  20
ROME            57  84  55  85 /  20  10   5  10
PEACHTREE CITY  58  83  56  84 /  20  10  10  10
VIDALIA         67  88  65  87 /  30  30  20  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS62 KCHS 151755
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
155 PM EDT TUE MAY 15 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRIMARY FORECAST ATTENTION CENTERS ON CONVECTION/SEVERE POTENTIAL
THIS AFTERNOON/EVENING.

THE REGION REMAINS BENEATH A BROAD/DEEP LAYER CYCLONIC FLOW REGIME
WHICH WILL PROMOTE SYNOPTIC SCALE LOW LEVEL CONVERGENCE PUNCTUATED
BY NUMEROUS/EMBEDDED MESOSCALE BOUNDARIES. IN PARTICULAR...SEA
BREEZE CONVERGENCE WILL BE MORE PROMINENT THAN WAS THE CASE MONDAY
AFTERNOON. ONCE THUNDERSTORMS DEVELOP...0-6 KM SHEAR 20-25 KNOTS
WILL AGAIN SUPPORT MULTICELL CONVECTION.

EARLY TUESDAY AFTERNOON...UPDRAFT ENTRAINMENT OF MID DRY AIR
DEPICTED BY WATER VAPOR IMAGERY OVER FORECAST AREA WILL LIMIT
INITIAL COVERAGE AND INTENSITY OF THUNDERSTORMS. HOWEVER...
MULTICELL THUNDERSTORMS SHOULD EXPAND IN COVERAGE AS THE
AFTERNOON PROGRESSES. DUE TO THE PRESENCE OF THIS DRY AIR ALOFT...
CAPPED POPS AT HIGH CHANCE INLAND...BUT LOCALLY HIGHER POPS COULD
EVENTUALLY BE REQUIRED. OTHERWISE...PREVIOUS THINKING REGARDING
THUNDERSTORM DEVELOPMENT AND THE POTENTIAL FOR ISOLATED SEVERE
THUNDERSTORMS HAS NOT CHANGED SINCE TUESDAY MORNING.

MODIFIED 12Z SOUNDINGS YIELDED SBCAPES 1500-2500 J/KG...AND THE
EARLY AFTERNOON SPC MESOANALYSIS ALREADY DEPICTED SBCAPES AROUND
3000 J/KG. FURTHER...DOWNDRAFT CAPES HAD INCREASED TO OVER 1000
J/KG...ACCOMPANIED BY WET BULB ZERO HEIGHTS AROUND 10 KFT AGL.
WITHIN THIS ENVIRONMENT...A FEW THUNDERSTORMS COULD BRIEFLY PULSE
TO SEVERE LEVELS MID AFTERNOON INTO THIS EVENING...PRODUCING DAMAGING
MICROBURSTS AND LARGE HAIL...ESPECIALLY WHERE THUNDERSTORM/MESOSCALE
BOUNDARY INTERACTIONS OCCUR. WILL CONTINUE TO HIGHLIGHT THE
ISOLATED SEVERE WEATHER THREAT WITHIN THE HAZARDOUS WEATHER
OUTLOOK.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...ISOLATED TO SCATTERED SHOWERS/STORMS WILL DIMINISH THROUGH
THE EVENING WITH THE LOSS OF DAYTIME HEATING. LINGERING OUTFLOW
BOUNDARIES WILL LIKELY DETERMINE THE FAVORED AREAS FOR ISOLATED TO
SCATTERED COVERAGE THROUGH THE LATE EVENING. LOWS WILL BE SIMILAR TO
PREVIOUS NIGHT WITH MID TO UPPER 60S EXPECTED.

WEDNESDAY...THE PESKY TROUGH ALOFT THAT HAS BEEN LOCATED UPSTREAM
THE PAST SEVERAL DAYS...WILL FINALLY BEGIN TO MOVE INTO THE
SE...WHILE ITS ASSOCIATED WEAK SURFACE COLD FRONT WILL BE FOUND
ACROSS THE CWFA. A DEEP SW FLOW IN ADVANCE OF THESE FEATURES WILL
TRANSPORT PLENTIFUL MOISTURE INTO SOUTHERN SC AND SE GA...WITH PWATS
AS HIGH AS AROUND 1.5 INCHES. INSTABILITY WILL ALSO BE
SUFFICIENT...WITH LIFTED INDICES NEAR -4 OR -5 AND SBCAPES OF AT
LEAST 1500 J/KG. LAPSE RATES MIGHT BE A LITTLE WEAK...BUT VARIOUS
PERTURBATIONS WILL MOVE THROUGH WITHIN THE SW FLOW ALOFT TO ASSIST
IN FORCING. AND IF THE SUB-TROPICAL JET FOUND MOVING OUT OF THE GULF
OF MEXICO IS DISPLACED JUST A LITTLE FURTHER NORTH...IT WOULD PUT US
IN THE LEFT FRONT QUAD. ALL THESE FACTORS POINT
TOWARD

GIVEN THE NEARBY COLD FRONT...THE SEA BREEZE AND VARIOUS LOW LEVEL
CONVERGENT BOUNDARIES...IF ANY OF THESE COLLIDE/INTERACT WITH ONE
ANOTHER...THEN WE COULD BE LOOKING AT SOME ISOLATED STRONG OR SEVERE
T-STORMS. DCAPES ARE NEAR 800 J/KG AND THERE WILL BE SOME DRY MID
LEVEL AIR. THAT ALONG WITH 500 MB TEMPS NEAR -13C SUGGESTS THAT
WHERE THE STRONGEST UPDRAFTS OCCUR THAT WE MIGHT DEVELOP A FEW
MULTICELL CLUSTERS. IF SO...THEN LOCALLY DAMAGING WINDS/MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST TSTMS IN THE
AFTERNOON/EARLY EVENING. SLOW MOVING STORMS TOWARD THE EAST CAN ALSO
RESULT IN LOCALIZED FLOODING. ACTIVITY WILL BECOME SCATTERED DURING
THE LATE MORNING AND AFTERNOON...WITH 40-50 POPS TO OCCUR AREA WIDE.

WE/LL COME CLOSE TO THE LOW LEVEL THICKNESS FORECAST IN REGARDS TO
MAX TEMPS...WITH HIGHEST READINGS MAINLY IN THE MID AND UPPER 80S.

THURSDAY...THE AFOREMENTIONED TROUGH ALOFT WILL DRIFT TO THE SE
COAST BY LATE IN THE DAY...AS THE REMNANTS OF THE WEAK COLD
FRONT...BY NOW MORE A BAROCLINIC ZONE WILL ALSO PUSH TOWARD THE
COAST. MOISTURE THOUGH IS STILL PLENTIFUL WITH PWATS CLOSE TO 1.5
INCHES...AND THERE IS AMPLE INSTABILITY AND MESO-SCALE BOUNDARIES
SUCH AS THE SEA BREEZE FOR CONVECTION TO FORM ALONG. WE/LL MAINTAIN
SLIGHT CHANCE AND CHANCE POPS...HIGHEST SOUTH OF BEAUFORT. TEMPS
WILL AGAIN BE ABOVE SEASONAL NORMALS WITH 850 MB TEMPS NEAR 11-12C.

FRIDAY...MUCH DRIER AIR WORKS ITS WAY INTO THE AREA...AS STRONG HIGH
PRESSURE BUILDS FROM THE NORTH AND NE. THIS WILL BE PRECEDED BY A
LOW LEVEL CONVERGENCE BOUNDARY OR WIND SURGE...WHICH MAY BE
ACCOMPANIED BY A NARROW BAND OF SHOWERS. OTHERWISE...THE MAIN
BAROCLINIC ZONE WILL HAVE SHIFTED INTO OR JUST SOUTH OF OUR SOUTHERN
ZONES. WHILE THE NORTHERN AND CENTRAL ZONES WILL TURN OUT
RAINFREE...SLIGHT CHANCE AND CHANCE POPS ARE IN ORDER NEAR AND SOUTH
OF I-16 WHERE THE BEST LOW LEVEL CONVERGENCE AND GREATEST LINGERING
MOISTURE WILL BE FOUND. BREEZY CONDITIONS WILL IMPACT COASTAL AREAS
WITH SOME PACKING OF THE PRESSURE GRADIENT AROUND LARGE HIGH
PRESSURE MOVING THROUGH THE NE STATES. TEMPS WILL BE A TAD COOLER
WITH THE ONSHORE FLOW...BUT STILL NEAR OR SLIGHTLY ABOVE NORMAL
DURING THE DAYTIME...WITH NOTICEABLY COOLER CONDITIONS WELL INLAND
AT NIGHT WITH SOME UPPER 50S EXPECTED.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
MAINLY VFR. HOWEVER...THUNDERSTORMS SHOULD IMPACT BOTH TERMINALS
THIS AFTERNOON...PERHAPS INTO EARLY EVENING. EXPECT AMENDMENTS TO
ADDRESS NEAR TERM CONVECTIVE TRENDS. THEN...LOW CHANCE OF MVFR OR
LOWER CONDITIONS LATE TONIGHT INTO EARLY WEDNESDAY IN A
SHOWER...STRATUS AND/OR FOG. THUNDERSTORMS ARE EXPECTED TO
REDEVELOP WEDNESDAY...BUT MAINLY 18Z OR LATER.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
THUNDERSTORMS COULD LOCALLY ALTER WINDS THIS AFTERNOON AND
TONIGHT. OTHERWISE...CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA
CRITERIA THROUGH TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA
OF S TO SW FLOW ON THE EAST SIDE OF BROAD LOW PRESSURE. SEA BREEZE
ENHANCEMENT COULD SUPPORT LOCAL WINDS AS HIGH AS 15-20 KT THIS
AFTERNOON... ESPECIALLY ON CHARLESTON HARBOR. OTHERWISE...WINDS OF
15 KTS OR LESS ARE EXPECTED. WAVE WATCH GUIDANCE CONTINUES TO
INITIALIZE WITH SEAS HIGHER THAN OBSERVED...THUS TAPERED SEAS FROM
2-4 FT WITHIN 20 NM TO 4 FT BEYOND.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE
WEEKEND...WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER
WINDS AND LARGER SEAS FRIDAY THROUGH SUNDAY. SCA/S SEEM ALMOST A
CERTAINTY DURING THAT TIME.

ALTHOUGH WATER TEMPS MIGHT STILL BE A LITTLE TOO LOW...GIVEN A
LIGHT WIND REGIME WITH AMPLE MOISTURE AND INSTABILITY...AND VARIOUS
LOW LEVEL CONVERGENT BOUNDARIES...WE WILL NEED TO BE ALERT FOR
POSSIBLE WATERSPOUT FORMATION THURSDAY MORNING.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL. WE WILL ADD MENTION TO THE
HAZARDOUS WEATHER OUTLOOK.

&&

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

&&

$$

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

000
FXUS62 KFFC 151745 AAB
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
145 PM EDT TUE MAY 15 2012


.PREV DISCUSSION... /ISSUED 1111 AM EDT TUE MAY 15 2012/

UPDATE...
SATELLITE IMAGERY STILL SHOWS A MAJOR CLOUD DECK IN NORTHWEST
GEORGIA. THIS DECK SHOULD START TO MIX OUT SOMETIME AROUND NOON
AND START TO BECOME SCATTERED. MADE CHANGES TO THE DEWPOINT AND
CURRENT TEMPERATURE TREND AS WE WERE A LITTLE DRY. NO OTHER
UPDATES AT THIS TIME.

PREV DISCUSSION... /ISSUED 746 AM EDT TUE MAY 15 2012/

PREV DISCUSSION...

SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED 411 AM EDT TUE MAY 15 2012/
CWA STILL REMAINS ON THE EASTERN SIDE OF THE UPPER LEVEL TROUGH AND
THIS TROUGHING PATTERN WILL REMAIN A FEATURE THROUGH THE SHORT TERM.
ALTHOUGH COLD FRONT HAS ALREADY MOVED INTO EAST CENTRAL GA...THE
WHOLE CWA WILL REMAIN SUSCEPTIBLE TO SUMMERLIKE SHOWERS AND
THUNDERSTORMS THROUGH THE SHORT TERM WITH THE UPPER LEVEL TROUGH.

FOR TODAY...THE SFC FRONT IS EXPECTED TO REMAIN ACROSS EASTERN
GEORGIA. THIS MAY HELP PROVIDE A FOCUS FOR AFTERNOON DEVELOPMENT AND
HAVE SHOWN BEST CHANCE OF SHOWERS AND THUNDERSTORMS FOR TODAY ACROSS
THE EASTERN HALF OF THE CWA. WITH GFS AND NAM MUCAPE VALUES NEAR
1500 J/KG FOR THE AFTERNOON AND NO SHEAR...CANNOT RULE OUT AN
ISOLATED STRONG STORM...BUT NOT EXPECTING SEVERE STORMS. SHOWERS AND
THUNDERSTORMS WILL DECREASE IN COVERAGE OVERNIGHT. FOR WEDNESDAY...
THE FRONT WILL SINK INTO SOUTH GEORGIA BUT WE WILL STILL SEE A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN AS THE TROUGHING
PATTERN ALOFT CONTINUES AND A SHORTWAVE SWINGS THROUGH NORTH
GEORGIA.

WITH MOSTLY SUNNY TO PARTY SUNNY SKIES EXPECTED AGAIN TODAY...LEANED
TOWARD MAV TEMPS /WARMER GUIDANCE/ FOR MAX TEMPS THIS AFTERNOON.
REST OF SHORT TERM TEMPS ARE CLOSE TO A MAV/MET BLEND.

11

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED 411 AM EDT TUE MAY 15 2012/
LATEST GFS RUN A TAF SLOWER THAN PREVIOUS WITH AXIS OF UPPER TROF
SWINGING EAST OF THE COUNTY WARNING AREA AND UPPER RIDGE BUILDING
IN BEHIND IT. GFS NOW INDICATING A WEAK BOUNDARY APPROACHING THE
TENNESSEE VALLEY THURSDAY WITH SOME DEEPER MOISTURE SPREADING INTO
EXTREME NORTHERN COUNTIES. MODELS HOLD ON TO REMNANTS OF WEAK
BOUNDARY SOMEWHERE NEAR THE TN/WRN NC BORDER THURSDAY NIGHT BEFORE
WASHING IT FRIDAY AS HIGH PRESSURE WEDGES DOWN THE APPALACHIANS
AND REMAIN DOMINANT OVER OUR AREA THROUGH THE WEEKEND. ECMWF MOST
AGGRESSIVE WITH SHOWING A WEAK COASTAL LOW FORMING NEAR THE
SOUTHEAST COAST OVER THE WEEKEND...BUT BOTH ECMWF AND GFS SIMILAR
WITH KEEPING BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE EAST
AND SOUTH OF OUR AREA. MAY BE GETTING INTO BETTER CHANCES FOR
PRECIP MONDAY/TUESDAY WITH EXTENDED PROGS INDICATING A FRONTAL
BOUNDARY DRIFTING SOUTHEAST FROM THE OHIO/TENNESSEE VALLEY REGION.

49

.AVIATION...
18Z UPDATE...
MAIN CONCERN FOR TODAY ARE THE CHANCES OF THUNDER. TODAYS SOUNDING
SUGGESTS THAT THUNDER IS MORE LIKELY TODAY THAN IT WAS YESTERDAY.
HAVE INCLUDED A TEMPO TO COVER CONVECTION LATER THIS AFTERNOON.
CURRENT TRENDS SUGGESTS THIS...HOWEVER...WE COULD SEE THUNDER
EARLIER AND THE TEMPO MAY NEED TO BE ADJUSTED. OTHERWISE EXPECT
VFR CONDITIONS THROUGH THE PERIOD.

//ATL CONFIDENCE...18Z UPDATE...
LOW CONFIDENCE ON THUNDER TODAY. HIGH CONFIDENCE ON ALL OTHER ELEMENTS.

GIBBS

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          83  62  84  59 /  30  30  20  10
ATLANTA         81  63  82  62 /  20  20  20  10
BLAIRSVILLE     77  55  80  54 /  30  30  20  10
CARTERSVILLE    81  57  84  54 /  20  20  10  10
COLUMBUS        85  64  86  61 /  20  20  20  10
GAINESVILLE     80  61  81  60 /  30  30  20  10
MACON           86  61  85  59 /  30  30  20  10
ROME            83  59  84  56 /  20  20  10  10
PEACHTREE CITY  82  57  83  55 /  20  20  20  10
VIDALIA         84  66  85  64 /  30  30  30  10

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

AVIATION...GIBBS

000
FXUS62 KCHS 151647
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1247 PM EDT TUE MAY 15 2012

.SYNOPSIS...
BROAD LOW PRESSURE AT THE SURFACE AND ALOFT WILL LINGER ACROSS
THE AREA THROUGH THURSDAY. STRONG HIGH PRESSURE WILL BUILD FROM
THE NORTH AND NORTHEAST LATE IN THE WEEK AND PERSIST ACROSS THE
REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRIMARY FORECAST ATTENTION CENTERS ON CONVECTION/SEVERE POTENTIAL
THIS AFTERNOON/EVENING.

EARLY TUESDAY AFTERNOON...UPDRAFT ENTRAINMENT OF MID DRY AIR
DEPICTED BY WATER VAPOR IMAGERY OVER FORECAST AREA WILL LIMIT
INITIAL COVERAGE AND INTENSITY OF THUNDERSTORMS. HOWEVER...
MULTICELL THUNDERSTORMS SHOULD EXPAND IN COVERAGE AS THE
AFTERNOON PROGRESSES. DUE TO THE PRESENCE OF THIS DRY AIR ALOFT...
CAPPED POPS AT HIGH CHANCE INLAND...BUT LOCALLY HIGHER POPS COULD
EVENTUALLY BE REQUIRED. OTHERWISE...PREVIOUS THINKING REGARDING
THUNDERSTORM DEVELOPMENT AND THE POTENTIAL FOR ISOLATED SEVERE
THUNDERSTORMS HAS NOT CHANGED SINCE TUESDAY MORNING.

THE REGION REMAINS BENEATH A BROAD/DEEP LAYER CYCLONIC FLOW REGIME
WHICH WILL PROMOTE SYNOPTIC SCALE LOW LEVEL CONVERGENCE PUNCTUATED
BY NUMEROUS/EMBEDDED MESOSCALE BOUNDARIES. IN PARTICULAR...SEA
BREEZE CONVERGENCE WILL BE MORE PROMINENT THAN WAS THE CASE MONDAY
AFTERNOON. ONCE THUNDERSTORMS DEVELOP...0-6 KM SHEAR 20-25 KNOTS
WILL AGAIN SUPPORT MULTICELL CONVECTION.

MODIFIED 12Z SOUNDINGS YIELDED SBCAPES 1500-2500 J/KG...AND THE
EARLY AFTERNOON SPC MESOANALYSIS ALREADY DEPICTED SBCAPES AROUND
3000 J/KG. FURTHER...DOWNDRAFT CAPES HAD INCREASED TO OVER 1000
J/KG...ACCOMPANIED BY WET BULB ZERO HEIGHTS AROUND 10 KFT AGL.
WITHIN THIS ENVIRONMENT...A FEW THUNDERSTORMS COULD BRIEFLY PULSE
TO SEVERE LEVELS MID AFTERNOON INTO THIS EVENING...PRODUCING DAMAGING
MICROBURSTS AND LARGE HAIL...ESPECIALLY WHERE THUNDERSTORM/MESOSCALE
BOUNDARY INTERACTIONS OCCUR. WILL CONTINUE TO HIGHLIGHT THE
ISOLATED SEVERE WEATHER THREAT WITHIN THE HAZARDOUS WEATHER
OUTLOOK.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...ISOLATED TO SCATTERED SHOWERS/STORMS WILL DIMINISH THROUGH
THE EVENING WITH THE LOSS OF DAYTIME HEATING. LINGERING OUTFLOW
BOUNDARIES WILL LIKELY DETERMINE THE FAVORED AREAS FOR ISOLATED TO
SCATTERED COVERAGE THROUGH THE LATE EVENING. LOWS WILL BE SIMILAR TO
PREVIOUS NIGHT WITH MID TO UPPER 60S EXPECTED.

WEDNESDAY...THE PESKY TROUGH ALOFT THAT HAS BEEN LOCATED UPSTREAM
THE PAST SEVERAL DAYS...WILL FINALLY BEGIN TO MOVE INTO THE
SE...WHILE ITS ASSOCIATED WEAK SURFACE COLD FRONT WILL BE FOUND
ACROSS THE CWFA. A DEEP SW FLOW IN ADVANCE OF THESE FEATURES WILL
TRANSPORT PLENTIFUL MOISTURE INTO SOUTHERN SC AND SE GA...WITH PWATS
AS HIGH AS AROUND 1.5 INCHES. INSTABILITY WILL ALSO BE
SUFFICIENT...WITH LIFTED INDICES NEAR -4 OR -5 AND SBCAPES OF AT
LEAST 1500 J/KG. LAPSE RATES MIGHT BE A LITTLE WEAK...BUT VARIOUS
PERTURBATIONS WILL MOVE THROUGH WITHIN THE SW FLOW ALOFT TO ASSIST
IN FORCING. AND IF THE SUB-TROPICAL JET FOUND MOVING OUT OF THE GULF
OF MEXICO IS DISPLACED JUST A LITTLE FURTHER NORTH...IT WOULD PUT US
IN THE LEFT FRONT QUAD. ALL THESE FACTORS POINT
TOWARD

GIVEN THE NEARBY COLD FRONT...THE SEA BREEZE AND VARIOUS LOW LEVEL
CONVERGENT BOUNDARIES...IF ANY OF THESE COLLIDE/INTERACT WITH ONE
ANOTHER...THEN WE COULD BE LOOKING AT SOME ISOLATED STRONG OR SEVERE
T-STORMS. DCAPES ARE NEAR 800 J/KG AND THERE WILL BE SOME DRY MID
LEVEL AIR. THAT ALONG WITH 500 MB TEMPS NEAR -13C SUGGESTS THAT
WHERE THE STRONGEST UPDRAFTS OCCUR THAT WE MIGHT DEVELOP A FEW
MULTICELL CLUSTERS. IF SO...THEN LOCALLY DAMAGING WINDS/MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST TSTMS IN THE
AFTERNOON/EARLY EVENING. SLOW MOVING STORMS TOWARD THE EAST CAN ALSO
RESULT IN LOCALIZED FLOODING. ACTIVITY WILL BECOME SCATTERED DURING
THE LATE MORNING AND AFTERNOON...WITH 40-50 POPS TO OCCUR AREA WIDE.

WE/LL COME CLOSE TO THE LOW LEVEL THICKNESS FORECAST IN REGARDS TO
MAX TEMPS...WITH HIGHEST READINGS MAINLY IN THE MID AND UPPER 80S.

THURSDAY...THE AFOREMENTIONED TROUGH ALOFT WILL DRIFT TO THE SE
COAST BY LATE IN THE DAY...AS THE REMNANTS OF THE WEAK COLD
FRONT...BY NOW MORE A BAROCLINIC ZONE WILL ALSO PUSH TOWARD THE
COAST. MOISTURE THOUGH IS STILL PLENTIFUL WITH PWATS CLOSE TO 1.5
INCHES...AND THERE IS AMPLE INSTABILITY AND MESO-SCALE BOUNDARIES
SUCH AS THE SEA BREEZE FOR CONVECTION TO FORM ALONG. WE/LL MAINTAIN
SLIGHT CHANCE AND CHANCE POPS...HIGHEST SOUTH OF BEAUFORT. TEMPS
WILL AGAIN BE ABOVE SEASONAL NORMALS WITH 850 MB TEMPS NEAR 11-12C.

FRIDAY...MUCH DRIER AIR WORKS ITS WAY INTO THE AREA...AS STRONG HIGH
PRESSURE BUILDS FROM THE NORTH AND NE. THIS WILL BE PRECEDED BY A
LOW LEVEL CONVERGENCE BOUNDARY OR WIND SURGE...WHICH MAY BE
ACCOMPANIED BY A NARROW BAND OF SHOWERS. OTHERWISE...THE MAIN
BAROCLINIC ZONE WILL HAVE SHIFTED INTO OR JUST SOUTH OF OUR SOUTHERN
ZONES. WHILE THE NORTHERN AND CENTRAL ZONES WILL TURN OUT
RAINFREE...SLIGHT CHANCE AND CHANCE POPS ARE IN ORDER NEAR AND SOUTH
OF I-16 WHERE THE BEST LOW LEVEL CONVERGENCE AND GREATEST LINGERING
MOISTURE WILL BE FOUND. BREEZY CONDITIONS WILL IMPACT COASTAL AREAS
WITH SOME PACKING OF THE PRESSURE GRADIENT AROUND LARGE HIGH
PRESSURE MOVING THROUGH THE NE STATES. TEMPS WILL BE A TAD COOLER
WITH THE ONSHORE FLOW...BUT STILL NEAR OR SLIGHTLY ABOVE NORMAL
DURING THE DAYTIME...WITH NOTICEABLY COOLER CONDITIONS WELL INLAND
AT NIGHT WITH SOME UPPER 50S EXPECTED.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR TO START. THEN...THUNDERSTORMS SHOULD IMPACT BOTH TERMINALS
THIS AFTERNOON...PERHAPS INTO EARLY EVENING. EXPECT AMENDMENTS
TO ADDRESS NEAR TERM CONVECTIVE TRENDS. THEN...LOW CHANCE OF MVFR
OR LOWER CONDITIONS LATE TONIGHT IN LOW STRATUS AND/OR FOG.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY NIGHT AND THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
AHEAD OF A WEAK COLD FRONT. SEA BREEZE ENHANCEMENT COULD SUPPORT
LOCAL WINDS AS HIGH AS 15-20 KT THIS AFTERNOON...ESPECIALLY ON
CHARLESTON HARBOR. OTHERWISE...WINDS OF 15 KTS OR LESS ARE EXPECTED.
WAVE WATCH GUIDANCE CONTINUES TO INITIALIZE WITH SEAS HIGHER THAN
OBSERVED...THUS TAPERED SEAS FROM 2-4 FT WITHIN 20 NM TO 4 FT
BEYOND.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE
WEEKEND...WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER
WINDS AND LARGER SEAS FRIDAY THROUGH SUNDAY. SCA/S SEEM ALMOST A
CERTAINTY DURING THAT TIME.

ALTHOUGH WATER TEMPS MIGHT STILL BE A LITTLE TOO LOW...GIVEN A
LIGHT WIND REGIME WITH AMPLE MOISTURE AND INSTABILITY...AND VARIOUS
LOW LEVEL CONVERGENT BOUNDARIES...WE WILL NEED TO BE ALERT FOR
POSSIBLE WATERSPOUT FORMATION THURSDAY MORNING.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL. WE WILL ADD MENTION TO THE
HAZARDOUS WEATHER OUTLOOK.

&&

.EQUIPMENT...
THE KCLX RADAR IS BACK IN SERVICE.

&&

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

&&

$$

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

000
FXUS62 KCAE 151628
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1228 PM EDT TUE MAY 15 2012

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY ACROSS THE REGION WILL PROVIDE A FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND THIS EVENING.
THE FRONT WILL SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE
INCREASED CHANCES OF RAIN ACROSS THE EASTERN MIDLANDS ON WEDNESDAY
BEFORE SHIFTING TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD
INTO THE REGION THURSDAY AND PROVIDE DRY WEATHER THROUGH THE
WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAK FRONTAL BOUNDARY AND LEFT OVER OUTFLOW BOUNDARIES WILL
PROVIDE A FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT. SPC HAS
REGION IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS THIS AFTERNOON
AND THIS EVENING. THE LATEST RAP SOUNDING FOR LATE THIS AFTERNOON
CONFIRMS THAT THE ATMOSPHERE SHOULD BE UNSTABLE ENOUGH TO PRODUCE
STRONG TO POTENTIALLY SEVERE STORMS. RAP LIS -5...CAPES OVER 2000
J/KG...TOTALS OVER 50. NAM SOUNDING GIVES CONVECTIVE TEMPERATURES
82-84 DEGREE THIS AFTERNOON. TEMPERATURES NOW RISING ABOVE 80...
SO CONVECTIVE ACTIVITY SHOULD BE ON THE INCREASE OVER THE NEXT
2-3 HOURS. WILL START WITH A SLIGHT CHANCE THIS AFTERNOON...THEN
INCREASE TO 40-50 PERCENT THIS EVENING. LOCAL WRF SHOWS SAME TREND
...LESS COVERAGE IN THE AFTERNOON WITH MOST OF THE COVERAGE BEING
IN THE EVENING HOURS. UPDATED HIGH TEMPERATURES THIS AFTERNOON
WITH MOSTLY LOWER 80S BUT DID INCLUDE SOME MIDDLE 80S IN THE SOUTH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
EXPECT LINGERING CONVECTION THIS EVENING ACROSS THE FORECAST AREA
SUPPORTED BY UPPER IMPULSES MOVING THROUGH THE SOUTHWESTERLY FLOW
ALOFT. WILL MAINTAIN HIGH CHANCE POPS EARLY WITH DIMINISHING
CHANCES THROUGH THE OVERNIGHT HOURS AS THE ATMOSPHERE BECOMES MORE
STABLE. EXPECT PLENTY OF CONVECTIVE DEBRIS CLOUDS AND THIS SHOULD
LIMIT THE AMOUNT OF RADIATIONAL COOLING OVERNIGHT. MIN
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE LOWER TO MID 60S.

THE SURFACE BOUNDARY SHIFTS VERY SLOWLY EASTWARD ACROSS THE
FORECAST AREA ON WEDNESDAY AND WILL AGAIN PROVIDE A FOCUS FOR
CONVECTIVE DEVELOPMENT. A WEST TO EAST GRADIENT IN DEEPER MOISTURE
WILL EXIST ACROSS THE REGION ON WEDNESDAY WITH THE BEST MOISTURE
BEING FOCUS CLOSER TO THE COASTAL PLAIN AND EASTERN MIDLANDS. THE
ATMOSPHERE WILL DESTABILIZE WITH DAYTIME HEATING AIDED BY COOLING
500 MB TEMPERATURES (-13C). WILL CONTINUE WITH THE CHANCE FOR
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...WITH
THE HIGHEST POPS ACROSS THE EASTERN MIDLANDS WHERE BETTER MOISTURE
IS FORECAST AND IN THE VICINITY OF THE SLOW MOVING SURFACE
BOUNDARY. ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE BUT THE
COVERAGE IS NOT EXPECTED TO BE AS GREAT. TEMPERATURES ON WEDNESDAY
WILL GENERALLY BE IN THE LOWER TO MID 80S.

THE UPPER TROUGH AXIS FINALLY SHIFTS EAST ACROSS THE FORECAST AREA
WEDNESDAY NIGHT AND THURSDAY AND DRIER AIR WILL BUILD IN FROM THE
NORTHWEST AS SURFACE HIGH PRESSURE BUILDS IN BEHIND THE DEPARTED
SURFACE FRONT. DESPITE THE COOLER AND DRIER AIR BUILDING INTO THE
REGION...PLENTY OF SUNSHINE IS EXPECTED THURSDAY WHICH WILL OFFSET
ANY WEAK COLD ADVECTION AND TEMPERATURES SHOULD REMAIN SEASONABLE
IN THE LOWER 80S WITH LITTLE CHANCE OF RAIN.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT INDICATING
TROUGHING ALONG THE WEST COAST DURING THE EXTENDED PERIOD WHICH
WILL RESULT IN DOWNSTREAM RIDGING AND RISING UPPER HEIGHTS OVER
THE FORECAST AREA. DRY WEATHER IS EXPECTED THROUGH THIS PERIOD AS
HIGH PRESSURE AT THE SURFACE AND ALOFT PROVIDE A RELATIVELY STABLE
AND DRY ATMOSPHERE. TEMPERATURES DURING THE PERIOD WILL BE NEAR
NORMAL WITH HIGHS IN THE 80S AND LOWS IN THE 50S TO LOWER 60S.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
MORNING SUN HAS HELPED TO BREAK UP THE FOG AND STRATUS. CONDITIONS
WILL BECOME VFR BY LATE MORNING. CONVERGENCE ASSOCIATED WITH THE
SURFACE TROUGH AND ANOTHER MID-LEVEL SHORTWAVE TROUGH PLUS
HEATING SUPPORTS THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
DID NOT INCLUDE THUNDERSTORMS IN THE TERMINAL FORECAST BECAUSE OF
TIMING UNCERTAINTY. STRONG HEATING WITH COLD AIR ALOFT ASSOCIATED
WITH THE UPPER TROUGH WILL RESULT IN MODERATE TO STRONG
INSTABILITY. ANY THUNDERSTORMS MAY CONTAIN STRONG WIND AND HAIL.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
ASSOCIATED WITH THE SLOW MOVING FRONT MAY OCCUR THROUGH WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
SYNOPSIS...07
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07

000
FXUS62 KFFC 151511
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1111 AM EDT TUE MAY 15 2012

.UPDATE...
SATELLITE IMAGERY STILL SHOWS A MAJOR CLOUD DECK IN NORTHWEST
GEORGIA. THIS DECK SHOULD START TO MIX OUT SOMETIME AROUND NOON
AND START TO BECOME SCATTERED. MADE CHANGES TO THE DEWPOINT AND
CURRENT TEMPERATURE TREND AS WE WERE A LITTLE DRY. NO OTHER
UPDATES AT THIS TIME.

&&

.PREV DISCUSSION... /ISSUED 746 AM EDT TUE MAY 15 2012/

PREV DISCUSSION...

SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED 411 AM EDT TUE MAY 15 2012/
CWA STILL REMAINS ON THE EASTERN SIDE OF THE UPPER LEVEL TROUGH AND
THIS TROUGHING PATTERN WILL REMAIN A FEATURE THROUGH THE SHORT TERM.
ALTHOUGH COLD FRONT HAS ALREADY MOVED INTO EAST CENTRAL GA...THE
WHOLE CWA WILL REMAIN SUSCEPTIBLE TO SUMMERLIKE SHOWERS AND
THUNDERSTORMS THROUGH THE SHORT TERM WITH THE UPPER LEVEL TROUGH.

FOR TODAY...THE SFC FRONT IS EXPECTED TO REMAIN ACROSS EASTERN
GEORGIA. THIS MAY HELP PROVIDE A FOCUS FOR AFTERNOON DEVELOPMENT AND
HAVE SHOWN BEST CHANCE OF SHOWERS AND THUNDERSTORMS FOR TODAY ACROSS
THE EASTERN HALF OF THE CWA. WITH GFS AND NAM MUCAPE VALUES NEAR
1500 J/KG FOR THE AFTERNOON AND NO SHEAR...CANNOT RULE OUT AN
ISOLATED STRONG STORM...BUT NOT EXPECTING SEVERE STORMS. SHOWERS AND
THUNDERSTORMS WILL DECREASE IN COVERAGE OVERNIGHT. FOR WEDNESDAY...
THE FRONT WILL SINK INTO SOUTH GEORGIA BUT WE WILL STILL SEE A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN AS THE TROUGHING
PATTERN ALOFT CONTINUES AND A SHORTWAVE SWINGS THROUGH NORTH
GEORGIA.

WITH MOSTLY SUNNY TO PARTY SUNNY SKIES EXPECTED AGAIN TODAY...LEANED
TOWARD MAV TEMPS /WARMER GUIDANCE/ FOR MAX TEMPS THIS AFTERNOON.
REST OF SHORT TERM TEMPS ARE CLOSE TO A MAV/MET BLEND.

11

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED 411 AM EDT TUE MAY 15 2012/
LATEST GFS RUN A TAF SLOWER THAN PREVIOUS WITH AXIS OF UPPER TROF
SWINGING EAST OF THE COUNTY WARNING AREA AND UPPER RIDGE BUILDING
IN BEHIND IT. GFS NOW INDICATING A WEAK BOUNDARY APPROACHING THE
TENNESSEE VALLEY THURSDAY WITH SOME DEEPER MOISTURE SPREADING INTO
EXTREME NORTHERN COUNTIES. MODELS HOLD ON TO REMNANTS OF WEAK
BOUNDARY SOMEWHERE NEAR THE TN/WRN NC BORDER THURSDAY NIGHT BEFORE
WASHING IT FRIDAY AS HIGH PRESSURE WEDGES DOWN THE APPALACHIANS
AND REMAIN DOMINANT OVER OUR AREA THROUGH THE WEEKEND. ECMWF MOST
AGGRESSIVE WITH SHOWING A WEAK COASTAL LOW FORMING NEAR THE
SOUTHEAST COAST OVER THE WEEKEND...BUT BOTH ECMWF AND GFS SIMILAR
WITH KEEPING BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE EAST
AND SOUTH OF OUR AREA. MAY BE GETTING INTO BETTER CHANCES FOR
PRECIP MONDAY/TUESDAY WITH EXTENDED PROGS INDICATING A FRONTAL
BOUNDARY DRIFTING SOUTHEAST FROM THE OHIO/TENNESSEE VALLEY REGION.

49

AVIATION...
12Z UPDATE...
FOG AND LOW CIGS ARE AFFECTING THE NORTHERN TAF SITES WITH EVEN
VLIFR AT A FEW OF THE SITES. ATL IS ON THE LINE OF THESE LOW CLOUDS
AND VSBYS SO HARD TO TELL IF IT WILL MAKE IT TO ATL BEFORE THE
SUN STARTS TO HELP DISSIPATE IT. CONDITIONS SHOULD BEGIN TO
IMPROVE BY 13-14Z. AFTER THAT SHOULD SEE AFTERNOON CU DEVELOP
AROUND 5KFT. ALTHOUGH A SLIGHT CHANCE OF THUNDERSTORMS DO EXIST
THIS AFTERNOON FOR THE ATL AND CSG AREA...NOT HIGH ENOUGH CHANCE
TO MENTION IN THE TAF. A LITTLE BIT HIGHER CHANCE AT MCN AND AHN
SO CONTINUED PROB30.

//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON WIND. LOW CONFIDENCE ON CIGS AND VSBYS THROUGH
15Z...THEN HIGH CONFIDENCE. LOW CONFIDENCE ON OCCURRENCE OF TSRA AT
TAF SITE THIS AFTERNOON.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          83  62  84  59 /  30  30  20  10
ATLANTA         81  63  82  62 /  20  20  20  10
BLAIRSVILLE     77  55  80  54 /  30  30  20  10
CARTERSVILLE    81  57  84  54 /  20  20  10  10
COLUMBUS        85  64  86  61 /  20  20  20  10
GAINESVILLE     80  61  81  60 /  30  30  20  10
MACON           86  61  85  59 /  30  30  20  10
ROME            83  59  84  56 /  20  20  10  10
PEACHTREE CITY  82  57  83  55 /  20  20  20  10
VIDALIA         84  66  85  64 /  30  30  30  10

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...GIBBS

000
FXUS62 KCHS 151417
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1017 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A VERY WEAK COLD FRONT WILL LINGER IN THE AREA THROUGH EARLY
THURSDAY...BEFORE DISSIPATING IN THE NEARBY ATLANTIC. STRONG HIGH
PRESSURE WILL BUILD FROM THE NORTH AND NORTHEAST LATE IN THE WEEK
AND PERSIST ACROSS THE REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRATUS ACROSS SOUTHERN/WESTERN COUNTIES TUESDAY MORNING WILL
TRANSITION TO A CUMULUS FIELD AS THE BOUNDARY LAYER WARMS/DEEPENS.

PRIMARY FORECAST ATTENTION CENTERS ON CONVECTION/SEVERE POTENTIAL
THIS AFTERNOON/EVENING. THE REGION REMAINS BENEATH A BROAD/DEEP LAYER
CYCLONIC FLOW REGIME WHICH WILL PROMOTE SYNOPTIC SCALE LOW LEVEL
CONVERGENCE AND NUMEROUS EMBEDDED MESOSCALE BOUNDARIES. INITIALLY...
SEA BREEZE CONVERGENCE SHOULD BECOME STRONGER THAN WAS THE CASE
MONDAY AFTERNOON...WHILE MORNING STRATUS WILL SUPPORT DIFFERENTIAL
HEATING BOUNDARIES ACROSS SOUTHERN/WESTERN COUNTIES. PER 12Z AREA
RAOBS...CONVECTIVE TEMPERATURES RANGE FROM AROUND 80F NORTH TO THE
MID 80S SOUTH...SO INITIAL THUNDERSTORMS COULD FIRE DURING THE
NOON-2 PM TIME FRAME IN SOME AREAS BUT COULD HOLD OFF UNTIL A
COUPLE OF HOURS LATER IN OTHER AREAS...ESPECIALLY ACROSS S/W
COUNTIES ONCE THUNDERSTORMS DEVELOP... 0-6 KM SHEAR 20-25 KNOTS
WILL AGAIN SUPPORT MULTICELL CONVECTION.

MODIFIED 12Z SOUNDINGS YIELD SBCAPES 1500-2500 J/KG AND WET BULB
ZERO HEIGHTS AROUND 10 KFT AGL. WITHIN THIS ENVIRONMENT...A FEW
THUNDERSTORMS COULD BRIEFLY PULSE TO SEVERE LEVELS...PRODUCING
DAMAGING MICROBURSTS AND LARGE HAIL...ESPECIALLY WHERE
THUNDERSTORM/MESOSCALE BOUNDARY INTERACTIONS OCCUR. WILL CONTINUE
TO HIGHLIGHT THE ISOLATED SEVERE WEATHER THREAT WITHIN THE
HAZARDOUS WEATHER OUTLOOK.

OF INTEREST...TUESDAY MORNING WATER VAPOR IMAGERY DEPICTED A
POCKET OF DRY MID LEVEL AIR ADVANCING N/NE INTO THE FORECAST AREA.
THIS DRY MID LEVEL AIR COULD ENHANCE THE POTENTIAL FOR DAMAGING
MICROBURSTS BUT COULD ALSO LIMIT OVERALL THUNDERSTORM COVERAGE.

MAINTAINED ONGOING HIGH CHANCE POPS AWAY FROM THE IMMEDIATE COAST
THIS AFTERNOON INTO EARLY EVENING. ADJUSTMENTS WILL BE REQUIRED AS
THE CONVECTIVE REGIME COMES INTO FOCUS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...ISOLATED TO SCATTERED SHOWERS/STORMS WILL DIMINISH THROUGH
THE EVENING WITH THE LOSS OF DAYTIME HEATING. LINGERING OUTFLOW
BOUNDARIES WILL LIKELY DETERMINE THE FAVORED AREAS FOR ISOLATED TO
SCATTERED COVERAGE THROUGH THE LATE EVENING. LOWS WILL BE SIMILAR TO
PREVIOUS NIGHT WITH MID TO UPPER 60S EXPECTED.

WEDNESDAY...THE PESKY TROUGH ALOFT THAT HAS BEEN LOCATED UPSTREAM
THE PAST SEVERAL DAYS...WILL FINALLY BEGIN TO MOVE INTO THE
SE...WHILE ITS ASSOCIATED WEAK SURFACE COLD FRONT WILL BE FOUND
ACROSS THE CWFA. A DEEP SW FLOW IN ADVANCE OF THESE FEATURES WILL
TRANSPORT PLENTIFUL MOISTURE INTO SOUTHERN SC AND SE GA...WITH PWATS
AS HIGH AS AROUND 1.5 INCHES. INSTABILITY WILL ALSO BE
SUFFICIENT...WITH LIFTED INDICES NEAR -4 OR -5 AND SBCAPES OF AT
LEAST 1500 J/KG. LAPSE RATES MIGHT BE A LITTLE WEAK...BUT VARIOUS
PERTURBATIONS WILL MOVE THROUGH WITHIN THE SW FLOW ALOFT TO ASSIST
IN FORCING. AND IF THE SUB-TROPICAL JET FOUND MOVING OUT OF THE GULF
OF MEXICO IS DISPLACED JUST A LITTLE FURTHER NORTH...IT WOULD PUT US
IN THE LEFT FRONT QUAD. ALL THESE FACTORS POINT
TOWARD

GIVEN THE NEARBY COLD FRONT...THE SEA BREEZE AND VARIOUS LOW LEVEL
CONVERGENT BOUNDARIES...IF ANY OF THESE COLLIDE/INTERACT WITH ONE
ANOTHER...THEN WE COULD BE LOOKING AT SOME ISOLATED STRONG OR SEVERE
T-STORMS. DCAPES ARE NEAR 800 J/KG AND THERE WILL BE SOME DRY MID
LEVEL AIR. THAT ALONG WITH 500 MB TEMPS NEAR -13C SUGGESTS THAT
WHERE THE STRONGEST UPDRAFTS OCCUR THAT WE MIGHT DEVELOP A FEW
MULTICELL CLUSTERS. IF SO...THEN LOCALLY DAMAGING WINDS/MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST TSTMS IN THE
AFTERNOON/EARLY EVENING. SLOW MOVING STORMS TOWARD THE EAST CAN ALSO
RESULT IN LOCALIZED FLOODING. ACTIVITY WILL BECOME SCATTERED DURING
THE LATE MORNING AND AFTERNOON...WITH 40-50 POPS TO OCCUR AREA WIDE.

WE/LL COME CLOSE TO THE LOW LEVEL THICKNESS FORECAST IN REGARDS TO
MAX TEMPS...WITH HIGHEST READINGS MAINLY IN THE MID AND UPPER 80S.

THURSDAY...THE AFOREMENTIONED TROUGH ALOFT WILL DRIFT TO THE SE
COAST BY LATE IN THE DAY...AS THE REMNANTS OF THE WEAK COLD
FRONT...BY NOW MORE A BAROCLINIC ZONE WILL ALSO PUSH TOWARD THE
COAST. MOISTURE THOUGH IS STILL PLENTIFUL WITH PWATS CLOSE TO 1.5
INCHES...AND THERE IS AMPLE INSTABILITY AND MESO-SCALE BOUNDARIES
SUCH AS THE SEA BREEZE FOR CONVECTION TO FORM ALONG. WE/LL MAINTAIN
SLIGHT CHANCE AND CHANCE POPS...HIGHEST SOUTH OF BEAUFORT. TEMPS
WILL AGAIN BE ABOVE SEASONAL NORMALS WITH 850 MB TEMPS NEAR 11-12C.

FRIDAY...MUCH DRIER AIR WORKS ITS WAY INTO THE AREA...AS STRONG HIGH
PRESSURE BUILDS FROM THE NORTH AND NE. THIS WILL BE PRECEDED BY A
LOW LEVEL CONVERGENCE BOUNDARY OR WIND SURGE...WHICH MAY BE
ACCOMPANIED BY A NARROW BAND OF SHOWERS. OTHERWISE...THE MAIN
BAROCLINIC ZONE WILL HAVE SHIFTED INTO OR JUST SOUTH OF OUR SOUTHERN
ZONES. WHILE THE NORTHERN AND CENTRAL ZONES WILL TURN OUT
RAINFREE...SLIGHT CHANCE AND CHANCE POPS ARE IN ORDER NEAR AND SOUTH
OF I-16 WHERE THE BEST LOW LEVEL CONVERGENCE AND GREATEST LINGERING
MOISTURE WILL BE FOUND. BREEZY CONDITIONS WILL IMPACT COASTAL AREAS
WITH SOME PACKING OF THE PRESSURE GRADIENT AROUND LARGE HIGH
PRESSURE MOVING THROUGH THE NE STATES. TEMPS WILL BE A TAD COOLER
WITH THE ONSHORE FLOW...BUT STILL NEAR OR SLIGHTLY ABOVE NORMAL
DURING THE DAYTIME...WITH NOTICEABLY COOLER CONDITIONS WELL INLAND
AT NIGHT WITH SOME UPPER 50S EXPECTED.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
KSAV...IFR STRATUS SHOULD GIVE WAY TO VFR CONDITIONS BY 16Z.
PERIODIC MVFR OR LOWER CONDITIONS ARE AGAIN EXPECTED IN SCATTERED
SHRA/TSRA FROM 19-23Z. THERE COULD AGAIN BE SOME MVFR CONDITIONS
LATE TONIGHT AS LOW STRATUS AND/OR FOG DEVELOPS...BUT WILL DEFER
THIS PROBABILITY TO LATER TAF ISSUANCES.

KCHS...VFR CONDITIONS WILL GENERALLY PREVAIL THROUGH 12Z
WEDNESDAY. CONVECTION WILL COME CLOSE TO THE TERMINAL THIS
AFTERNOON...BUT PRESENT INDICATIONS ARE THAT THE BULK OF THE
ACTIVITY WILL BE FOUND FURTHER INLAND. WE/LL CARRY A FEW HOURS OF
VCTS...WITH LATER ADJUSTMENTS PENDING RADAR TRENDS. LOW END CHANCE
OF MVFR CONDITIONS LATE TONIGHT IN LOW STRATUS AND/OR FOG.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY OR PERHAPS THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
AHEAD OF A WEAK COLD FRONT. SEA BREEZE ENHANCEMENT COULD SUPPORT
LOCAL WINDS AS HIGH AS 15-20 KT THIS AFTERNOON...ESPECIALLY ON
CHARLESTON HARBOR. OTHERWISE...WINDS OF 15 KTS OR LESS ARE EXPECTED.
WAVE WATCH GUIDANCE CONTINUES TO INITIALIZE WITH SEAS HIGHER THAN
OBSERVED...SO I HAVE TAPERED THEM DOWNWARD TO SHOW 2-4 FT WITHIN
20 NM AND A SOLID 4 FT BEYOND.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE
WEEKEND...WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER
WINDS AND LARGER SEAS FRIDAY THROUGH SUNDAY. SCA/S SEEM ALMOST A
CERTAINTY DURING THAT TIME.

ALTHOUGH WATER TEMPS MIGHT STILL BE A LITTLE TOO LOW...GIVEN A
LIGHT WIND REGIME WITH AMPLE MOISTURE AND INSTABILITY...AND VARIOUS
LOW LEVEL CONVERGENT BOUNDARIES...WE WILL NEED TO BE ALERT FOR
POSSIBLE WATERSPOUT FORMATION THURSDAY MORNING.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL. WE WILL ADD MENTION TO THE
HAZARDOUS WEATHER OUTLOOK.

&&

.EQUIPMENT...
KCLX RADAR IS DOWN UNTIL FURTHER NOTICE DUE TO A WIDEBAND FAILURE/SIGNAL
PROCESSOR COMMS ERROR. USERS ARE DIRECTED TO THE FOLLOWING
SURROUNDING RADARS IN THE INTERIM...

KLTX...WILMINGTON
KCAE...COLUMBIA
KFFC...ATLANTA/PEACHTREE CITY
KJAX...JACKSONVILLE
KJGX...WARNER ROBBINS
KVAX...VALDOSTA

&&

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

&&

$$

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

000
FXUS62 KCAE 151349
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
949 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A NEARLY STATIONARY FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR
SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON. THE FRONT WILL
SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE INCREASED CHANCES
OF RAIN ACROSS THE EASTERN MIDLANDS ON WEDNESDAY BEFORE SHIFTING
TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION
THURSDAY AND PROVIDE DRY WEATHER THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH AND ANOTHER MID-
LEVEL SHORTWAVE TROUGH PLUS HEATING SUPPORTS SHOWERS AND
THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. USED THE HIGHER
GUIDANCE POPS BECAUSE OF THIS SUPPORT. LOW-LEVEL MOISTURE
ASSOCIATED WITH CONVERGENCE INTO THE SURFACE TROUGH WILL REMAIN
HIGH TODAY. UPPER-LEVEL MOISTURE WILL BE A LITTLE LESS COMPARED TO
THE PAST FEW DAYS. EXPECT THE DIMINISHED MOISTURE WILL LEAD TO
MORE HEATING AND INSTABILITY. LATEST RAP SOUNDING SHOWS ATMOSPHERE
BECOMING UNSTABLE LATE THIS AFTERNOON WITH LIS -5...CAPES OVER
2000 J/KG...AND TOTALS OVER 50. OTHER MODELS ALSO SHOW MODERATE
TO STRONG INSTABILITY THIS AFTERNOON. SPC HAS ARE OUTLOOKED IN A
SLIGHT RISK...SO THERE COULD BE POSSIBLY DAMAGING WIND AND HAIL
WITH A FEW OF THE THUNDERSTORMS. USED THE GUIDANCE CONSENSUS FOR
THE TEMPERATURE FORECAST.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
EXPECT LINGERING CONVECTION THIS EVENING ACROSS THE FORECAST AREA
SUPPORTED BY UPPER IMPULSES MOVING THROUGH THE SOUTHWESTERLY FLOW
ALOFT. WILL MAINTAIN HIGH CHANCE POPS EARLY WITH DIMINISHING
CHANCES THROUGH THE OVERNIGHT HOURS AS THE ATMOSPHERE BECOMES MORE
STABLE. EXPECT PLENTY OF CONVECTIVE DEBRIS CLOUDS AND THIS SHOULD
LIMIT THE AMOUNT OF RADIATIONAL COOLING OVERNIGHT. MIN
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE LOWER TO MID 60S.

THE SURFACE BOUNDARY SHIFTS VERY SLOWLY EASTWARD ACROSS THE
FORECAST AREA ON WEDNESDAY AND WILL AGAIN PROVIDE A FOCUS FOR
CONVECTIVE DEVELOPMENT. A WEST TO EAST GRADIENT IN DEEPER MOISTURE
WILL EXIST ACROSS THE REGION ON WEDNESDAY WITH THE BEST MOISTURE
BEING FOCUS CLOSER TO THE COASTAL PLAIN AND EASTERN MIDLANDS. THE
ATMOSPHERE WILL DESTABILIZE WITH DAYTIME HEATING AIDED BY COOLING
500 MB TEMPERATURES (-13C). WILL CONTINUE WITH THE CHANCE FOR
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...WITH
THE HIGHEST POPS ACROSS THE EASTERN MIDLANDS WHERE BETTER MOISTURE
IS FORECAST AND IN THE VICINITY OF THE SLOW MOVING SURFACE
BOUNDARY. ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE BUT THE
COVERAGE IS NOT EXPECTED TO BE AS GREAT. TEMPERATURES ON WEDNESDAY
WILL GENERALLY BE IN THE LOWER TO MID 80S.

THE UPPER TROUGH AXIS FINALLY SHIFTS EAST ACROSS THE FORECAST AREA
WEDNESDAY NIGHT AND THURSDAY AND DRIER AIR WILL BUILD IN FROM THE
NORTHWEST AS SURFACE HIGH PRESSURE BUILDS IN BEHIND THE DEPARTED
SURFACE FRONT. DESPITE THE COOLER AND DRIER AIR BUILDING INTO THE
REGION...PLENTY OF SUNSHINE IS EXPECTED THURSDAY WHICH WILL OFFSET
ANY WEAK COLD ADVECTION AND TEMPERATURES SHOULD REMAIN SEASONABLE
IN THE LOWER 80S WITH LITTLE CHANCE OF RAIN.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT INDICATING
TROUGHING ALONG THE WEST COAST DURING THE EXTENDED PERIOD WHICH
WILL RESULT IN DOWNSTREAM RIDGING AND RISING UPPER HEIGHTS OVER
THE FORECAST AREA. DRY WEATHER IS EXPECTED THROUGH THIS PERIOD AS
HIGH PRESSURE AT THE SURFACE AND ALOFT PROVIDE A RELATIVELY STABLE
AND DRY ATMOSPHERE. TEMPERATURES DURING THE PERIOD WILL BE NEAR
NORMAL WITH HIGHS IN THE 80S AND LOWS IN THE 50S TO LOWER 60S.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
MORNING SUN HAS HELPED TO BREAK UP THE FOG AND STRATUS. CONDITIONS
WILL BECOME VFR BY LATE MORNING. CONVERGENCE ASSOCIATED WITH THE
SURFACE TROUGH AND ANOTHER MID-LEVEL SHORTWAVE TROUGH PLUS
HEATING SUPPORTS THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON.
DID NOT INCLUDE THUNDERSTORMS IN THE TERMINAL FORECAST BECAUSE OF
TIMING UNCERTAINTY. STRONG HEATING WITH COLD AIR ALOFT ASSOCIATED
WITH THE UPPER TROUGH WILL RESULT IN MODERATE TO STRONG
INSTABILITY. ANY THUNDERSTORMS MAY CONTAIN STRONG WIND AND HAIL.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
ASSOCIATED WITH THE SLOW MOVING FRONT MAY OCCUR THROUGH WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
SYNOPSIS...
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07

000
FXUS62 KFFC 151146 AAA
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
746 AM EDT TUE MAY 15 2012

.PREV DISCUSSION...

SHORT TERM /TODAY THROUGH WEDNESDAY/...
/ISSUED 411 AM EDT TUE MAY 15 2012/
CWA STILL REMAINS ON THE EASTERN SIDE OF THE UPPER LEVEL TROUGH AND
THIS TROUGHING PATTERN WILL REMAIN A FEATURE THROUGH THE SHORT TERM.
ALTHOUGH COLD FRONT HAS ALREADY MOVED INTO EAST CENTRAL GA...THE
WHOLE CWA WILL REMAIN SUSCEPTIBLE TO SUMMERLIKE SHOWERS AND
THUNDERSTORMS THROUGH THE SHORT TERM WITH THE UPPER LEVEL TROUGH.

FOR TODAY...THE SFC FRONT IS EXPECTED TO REMAIN ACROSS EASTERN
GEORGIA. THIS MAY HELP PROVIDE A FOCUS FOR AFTERNOON DEVELOPMENT AND
HAVE SHOWN BEST CHANCE OF SHOWERS AND THUNDERSTORMS FOR TODAY ACROSS
THE EASTERN HALF OF THE CWA. WITH GFS AND NAM MUCAPE VALUES NEAR
1500 J/KG FOR THE AFTERNOON AND NO SHEAR...CANNOT RULE OUT AN
ISOLATED STRONG STORM...BUT NOT EXPECTING SEVERE STORMS. SHOWERS AND
THUNDERSTORMS WILL DECREASE IN COVERAGE OVERNIGHT. FOR WEDNESDAY...
THE FRONT WILL SINK INTO SOUTH GEORGIA BUT WE WILL STILL SEE A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN AS THE TROUGHING
PATTERN ALOFT CONTINUES AND A SHORTWAVE SWINGS THROUGH NORTH
GEORGIA.

WITH MOSTLY SUNNY TO PARTY SUNNY SKIES EXPECTED AGAIN TODAY...LEANED
TOWARD MAV TEMPS /WARMER GUIDANCE/ FOR MAX TEMPS THIS AFTERNOON.
REST OF SHORT TERM TEMPS ARE CLOSE TO A MAV/MET BLEND.

11

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED 411 AM EDT TUE MAY 15 2012/
LATEST GFS RUN A TAF SLOWER THAN PREVIOUS WITH AXIS OF UPPER TROF
SWINGING EAST OF THE COUNTY WARNING AREA AND UPPER RIDGE BUILDING
IN BEHIND IT. GFS NOW INDICATING A WEAK BOUNDARY APPROACHING THE
TENNESSEE VALLEY THURSDAY WITH SOME DEEPER MOISTURE SPREADING INTO
EXTREME NORTHERN COUNTIES. MODELS HOLD ON TO REMNANTS OF WEAK
BOUNDARY SOMEWHERE NEAR THE TN/WRN NC BORDER THURSDAY NIGHT BEFORE
WASHING IT FRIDAY AS HIGH PRESSURE WEDGES DOWN THE APPALACHIANS
AND REMAIN DOMINANT OVER OUR AREA THROUGH THE WEEKEND. ECMWF MOST
AGGRESSIVE WITH SHOWING A WEAK COASTAL LOW FORMING NEAR THE
SOUTHEAST COAST OVER THE WEEKEND...BUT BOTH ECMWF AND GFS SIMILAR
WITH KEEPING BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE EAST
AND SOUTH OF OUR AREA. MAY BE GETTING INTO BETTER CHANCES FOR
PRECIP MONDAY/TUESDAY WITH EXTENDED PROGS INDICATING A FRONTAL
BOUNDARY DRIFTING SOUTHEAST FROM THE OHIO/TENNESSEE VALLEY REGION.

49

&&

.AVIATION...
12Z UPDATE...
FOG AND LOW CIGS ARE AFFECTING THE NORTHERN TAF SITES WITH EVEN
VLIFR AT A FEW OF THE SITES. ATL IS ON THE LINE OF THESE LOW CLOUDS
AND VSBYS SO HARD TO TELL IF IT WILL MAKE IT TO ATL BEFORE THE
SUN STARTS TO HELP DISSIPATE IT. CONDITIONS SHOULD BEGIN TO
IMPROVE BY 13-14Z. AFTER THAT SHOULD SEE AFTERNOON CU DEVELOP
AROUND 5KFT. ALTHOUGH A SLIGHT CHANCE OF THUNDERSTORMS DO EXIST
THIS AFTERNOON FOR THE ATL AND CSG AREA...NOT HIGH ENOUGH CHANCE
TO MENTION IN THE TAF. A LITTLE BIT HIGHER CHANCE AT MCN AND AHN
SO CONTINUED PROB30.

//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON WIND. LOW CONFIDENCE ON CIGS AND VSBYS THROUGH
15Z...THEN HIGH CONFIDENCE. LOW CONFIDENCE ON OCCURRENCE OF TSRA AT
TAF SITE THIS AFTERNOON.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          83  62  84  59 /  30  30  20  10
ATLANTA         81  63  82  62 /  20  20  20  10
BLAIRSVILLE     77  55  80  54 /  30  30  20  10
CARTERSVILLE    81  57  84  54 /  20  20  10  10
COLUMBUS        85  64  86  61 /  20  20  20  10
GAINESVILLE     80  61  81  60 /  30  30  20  10
MACON           86  61  85  59 /  30  30  20  10
ROME            83  59  84  56 /  20  20  10  10
PEACHTREE CITY  82  57  83  55 /  20  20  20  10
VIDALIA         84  66  85  64 /  30  30  30  10

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS62 KCHS 151138
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
738 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A VERY WEAK COLD FRONT WILL LINGER IN THE AREA THROUGH EARLY
THURSDAY...BEFORE DISSIPATING IN THE NEARBY ATLANTIC. STRONG HIGH
PRESSURE WILL BUILD FROM THE NORTH AND NORTHEAST LATE IN THE WEEK
AND PERSIST ACROSS THE REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE OVERALL SETUP TODAY IS VERY MUCH LIKE MONDAY. THE REGION WILL
BE IN A BAND OF SW FLOW ALOFT POSITIONED EAST OF A STAGNANT TROF
THAT STRETCHES FROM THE TN VALLEY TO EAST TX. AT THE SURFACE...THE
WEAK SURFACE LOW AND ILL-DEFINED COLD FRONT WILL MOVE SLIGHTLY
CLOSER TO THE FORECAST AREA THROUGH THE DAY. SO THE PRIMARY
FORECAST PROBLEM REVOLVES AROUND THE INITIATION AND COVERAGE OF
DIURNAL CONVECTION...AND THE POTENTIAL FOR STRONG/SEVERE STORMS.
MODEL THICKNESSES ARE QUITE WARM TODAY AND SUPPORT HIGHS IN THE
UPPER 80S...AND I HAVE WARMED TEMPS A FEW DEGREES ACROSS THE
BOARD. MODEL TIME HEIGHTS AND SOUNDINGS SHOW LESS LOW LEVEL
MOISTURE TODAY WHICH IS EXPECTED TO SUPPORT MORE BREAKS IN THE CU
FIELD AND BETTER INSOLATION. THIS STRONG HEATING UNDER A MID MAY
SUN IS EXPECTED TO RESULT IN AN UNCAPPED AND MODERATELY UNSTABLE
AIRMASS. HOWEVER...VARIOUS MODEL SOLUTIONS DEPICT A PERIOD OF NVA
INTO AT LEAST THE EARLY AFTERNOON...WHICH MAY DELAY CONVECTIVE
INITIATION INTO THE MID OR LATE AFTERNOON. I HAVE FAVORED A NAM
LIKE POP TREND FOR THE DAY WHICH RESULTS IN THINGS BEING DRY
THROUGH MID AFTERNOON...AND THEN CONVECTION FIRING ALONG THE SEA
BREEZE AS WELL AS INTERIOR SE GA. THIS CONVECTION IS EXPECTED TO
THEN SPREAD EASTWARD INTO THE EVENING REACHING FAR SOUTHERN SC
THROUGH THE LATE EVENING. COVERAGE SHOULD DIMINISH RATHER QUICKLY
WITH THE LOSS OF HEATING.

REGARDING THE SEVERE POTENTIAL...MODEL SOUNDINGS SHOW 1500-2000 J/KG
OF CAPE WITH LOTS OF MID-LEVEL DRY AIR. THIS RESULTS IN DCAPES
AROUND 1000 J/KG WITH A WET BULB ZERO HEIGHT IN THE 9-10 KFT RANGE.
WITH 0-6 KM SHEAR AROUND 25 KTS...THE ATMOSPHERE APPEARS SUPPORTIVE
FOR THE THREAT OF ISOLATED SEVERE STORMS...WITH BOTH LARGE HAIL AND
DAMAGING WIND GUSTS POSSIBLE. WILL ADD A SEVERE MENTION TO THE HWO.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...ISOLATED TO SCATTERED SHOWERS/STORMS WILL DIMINISH THROUGH
THE EVENING WITH THE LOSS OF DAYTIME HEATING. LINGERING OUTFLOW
BOUNDARIES WILL LIKELY DETERMINE THE FAVORED AREAS FOR ISOLATED TO
SCATTERED COVERAGE THROUGH THE LATE EVENING. LOWS WILL BE SIMILAR TO
PREVIOUS NIGHT WITH MID TO UPPER 60S EXPECTED.

WEDNESDAY...THE PESKY TROUGH ALOFT THAT HAS BEEN LOCATED UPSTREAM
THE PAST SEVERAL DAYS...WILL FINALLY BEGIN TO MOVE INTO THE
SE...WHILE ITS ASSOCIATED WEAK SURFACE COLD FRONT WILL BE FOUND
ACROSS THE CWFA. A DEEP SW FLOW IN ADVANCE OF THESE FEATURES WILL
TRANSPORT PLENTIFUL MOISTURE INTO SOUTHERN SC AND SE GA...WITH PWATS
AS HIGH AS AROUND 1.5 INCHES. INSTABILITY WILL ALSO BE
SUFFICIENT...WITH LIFTED INDICES NEAR -4 OR -5 AND SBCAPES OF AT
LEAST 1500 J/KG. LAPSE RATES MIGHT BE A LITTLE WEAK...BUT VARIOUS
PERTURBATIONS WILL MOVE THROUGH WITHIN THE SW FLOW ALOFT TO ASSIST
IN FORCING. AND IF THE SUB-TROPICAL JET FOUND MOVING OUT OF THE GULF
OF MEXICO IS DISPLACED JUST A LITTLE FURTHER NORTH...IT WOULD PUT US
IN THE LEFT FRONT QUAD. ALL THESE FACTORS POINT
TOWARD

GIVEN THE NEARBY COLD FRONT...THE SEA BREEZE AND VARIOUS LOW LEVEL
CONVERGENT BOUNDARIES...IF ANY OF THESE COLLIDE/INTERACT WITH ONE
ANOTHER...THEN WE COULD BE LOOKING AT SOME ISOLATED STRONG OR SEVERE
T-STORMS. DCAPES ARE NEAR 800 J/KG AND THERE WILL BE SOME DRY MID
LEVEL AIR. THAT ALONG WITH 500 MB TEMPS NEAR -13C SUGGESTS THAT
WHERE THE STRONGEST UPDRAFTS OCCUR THAT WE MIGHT DEVELOP A FEW
MULTICELL CLUSTERS. IF SO...THEN LOCALLY DAMAGING WINDS/MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST TSTMS IN THE
AFTERNOON/EARLY EVENING. SLOW MOVING STORMS TOWARD THE EAST CAN ALSO
RESULT IN LOCALIZED FLOODING. ACTIVITY WILL BECOME SCATTERED DURING
THE LATE MORNING AND AFTERNOON...WITH 40-50 POPS TO OCCUR AREA WIDE.

WE/LL COME CLOSE TO THE LOW LEVEL THICKNESS FORECAST IN REGARDS TO
MAX TEMPS...WITH HIGHEST READINGS MAINLY IN THE MID AND UPPER 80S.

THURSDAY...THE AFOREMENTIONED TROUGH ALOFT WILL DRIFT TO THE SE
COAST BY LATE IN THE DAY...AS THE REMNANTS OF THE WEAK COLD
FRONT...BY NOW MORE A BAROCLINIC ZONE WILL ALSO PUSH TOWARD THE
COAST. MOISTURE THOUGH IS STILL PLENTIFUL WITH PWATS CLOSE TO 1.5
INCHES...AND THERE IS AMPLE INSTABILITY AND MESO-SCALE BOUNDARIES
SUCH AS THE SEA BREEZE FOR CONVECTION TO FORM ALONG. WE/LL MAINTAIN
SLIGHT CHANCE AND CHANCE POPS...HIGHEST SOUTH OF BEAUFORT. TEMPS
WILL AGAIN BE ABOVE SEASONAL NORMALS WITH 850 MB TEMPS NEAR 11-12C.

FRIDAY...MUCH DRIER AIR WORKS ITS WAY INTO THE AREA...AS STRONG HIGH
PRESSURE BUILDS FROM THE NORTH AND NE. THIS WILL BE PRECEDED BY A
LOW LEVEL CONVERGENCE BOUNDARY OR WIND SURGE...WHICH MAY BE
ACCOMPANIED BY A NARROW BAND OF SHOWERS. OTHERWISE...THE MAIN
BAROCLINIC ZONE WILL HAVE SHIFTED INTO OR JUST SOUTH OF OUR SOUTHERN
ZONES. WHILE THE NORTHERN AND CENTRAL ZONES WILL TURN OUT
RAINFREE...SLIGHT CHANCE AND CHANCE POPS ARE IN ORDER NEAR AND SOUTH
OF I-16 WHERE THE BEST LOW LEVEL CONVERGENCE AND GREATEST LINGERING
MOISTURE WILL BE FOUND. BREEZY CONDITIONS WILL IMPACT COASTAL AREAS
WITH SOME PACKING OF THE PRESSURE GRADIENT AROUND LARGE HIGH
PRESSURE MOVING THROUGH THE NE STATES. TEMPS WILL BE A TAD COOLER
WITH THE ONSHORE FLOW...BUT STILL NEAR OR SLIGHTLY ABOVE NORMAL
DURING THE DAYTIME...WITH NOTICEABLY COOLER CONDITIONS WELL INLAND
AT NIGHT WITH SOME UPPER 50S EXPECTED.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
KSAV...LOW STRATUS WILL IMPACT THE TERMINAL THROUGH 14Z WITH MVFR
CONDITIONS. VFR CONDITIONS WILL RETURN FOR THE LATE MORNING AND
EARLY AFTERNOON...BUT PERIODIC MVFR CONDITIONS ARE AGAIN EXPECTED
IN SCATTERED SHRA/TSRA FROM 19-23Z. THERE COULD AGAIN BE SOME MVFR
CONDITIONS LATE TONIGHT AS LOW STRATUS AND/OR FOG DEVELOPS...BUT
WILL DEFER THIS PROBABILITY TO LATER TAF ISSUANCES.

KCHS...ISOLATED SHRA WILL MOVE AWAY FROM THE TERMINAL EARLY THIS
MORNING...WITH VFR CONDITIONS TO GENERALLY PREVAIL THROUGH 12Z
WEDNESDAY. CONVECTION WILL COME CLOSE TO THE TERMINAL THIS
AFTERNOON...BUT PRESENT INDICATIONS ARE THAT THE BULK OF THE
ACTIVITY WILL BE FOUND FURTHER INLAND. WE/LL CARRY A FEW HOURS OF
VCTS...WITH LATER ADJUSTMENTS PENDING RADAR TRENDS. LOW END CHANCE
OF MVFR CONDITIONS LATE TONIGHT IN LOW STRATUS AND/OR FOG.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE WEDNESDAY OR PERHAPS THURSDAY DUE TO DIURNAL SHRA/TSRA.
VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND SATURDAY.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
AHEAD OF A WEAK COLD FRONT...WITH WINDS OF 15 KTS OR LESS EXPECTED.
WAVE WATCH GUIDANCE CONTINUES TO INITIALIZE WITH SEAS HIGHER THAN
OBSERVED...SO I HAVE TAPERED THEM DOWNWARD TO SHOW 2-4 FT WITHIN 20
NM AND A SOLID 4 FT BEYOND.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE
WEEKEND...WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER
WINDS AND LARGER SEAS FRIDAY THROUGH SUNDAY. SCA/S SEEM ALMOST A
CERTAINTY DURING THAT TIME.

ALTHOUGH WATER TEMPS MIGHT STILL BE A LITTLE TOO LOW...GIVEN A
LIGHT WIND REGIME WITH AMPLE MOISTURE AND INSTABILITY...AND VARIOUS
LOW LEVEL CONVERGENT BOUNDARIES...WE WILL NEED TO BE ALERT FOR
POSSIBLE WATERSPOUT FORMATION THURSDAY MORNING.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL. WE WILL ADD MENTION TO THE
HAZARDOUS WEATHER OUTLOOK.

&&

.EQUIPMENT...
KCLX RADAR IS DOWN UNTIL FURTHER NOTICE DUE TO A WIDEBAND FAILURE/SIGNAL
PROCESSOR COMMS ERROR. EXPECTING IT TO BE BACK IN OPERATION BY
LATE MORNING OR EARLY AFTERNOON. USERS ARE DIRECTED TO THE
FOLLOWING SURROUNDING RADARS IN THE INTERIM...

KLTX...WILMINGTON
KCAE...COLUMBIA
KFFC...ATLANTA/PEACHTREE CITY
KJAX...JACKSONVILLE
KJGX...WARNER ROBBINS
KVAX...VALDOSTA

&&

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

&&

$$

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

000
FXUS62 KCHS 150918
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
518 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A VERY WEAK COLD FRONT WILL LINGER IN THE AREA THROUGH EARLY
THURSDAY...BEFORE DISSIPATING IN THE NEARBY ATLANTIC. STRONG HIGH
PRESSURE WILL BUILD FROM THE NORTH AND NORTHEAST LATE IN THE WEEK
AND PERSIST ACROSS THE REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS MORNING...OTHER THAN AN ISOLATED SHOWER OR TWO ACROSS
EASTERN CHARLESTON COUNTY AND SCATTERED SHOWERS WELL
OFFSHORE...PRECIP HAS ENDED ACROSS THE FORECAST AREA. TEMPS ARE
CURRENTLY IN THE UPPER 60S TO LOW 70S...AND ENOUGH S TO SW FLOW
SHOULD STAY UP THROUGH THE REMAINDER OF THE NIGHT TO KEEP TEMPS FROM
FALLING MUCH FURTHER. SCATTERED TO OCCASIONALLY BROKEN STRATUS WILL
AFFECT PORTIONS OF THE AREA THROUGH SUNRISE BUT ISN/T LIKELY TO
BECOME WIDESPREAD. THE PERSISTENT LOW LEVEL FLOW IS EXPECTED TO KEEP
THE ATMOSPHERE MIXED ENOUGH TO PRECLUDE FOG DEVELOPMENT AS WELL.

TODAY...THE OVERALL SETUP IS VERY MUCH LIKE MONDAY. THE REGION WILL
BE IN A BAND OF SW FLOW ALOFT POSITIONED EAST OF A STAGNANT TROF
THAT STRETCHES FROM THE TN VALLEY TO EAST TX. AT THE SURFACE...THE
WEAK SURFACE LOW AND ILL-DEFINED COLD FRONT WILL MOVE SLIGHTLY
CLOSER TO THE FORECAST AREA THROUGH THE DAY. SO THE PRIMARY FORECAST
PROBLEM REVOLVES AROUND THE INITIATION AND COVERAGE OF DIURNAL
CONVECTION...AND THE POTENTIAL FOR STRONG/SEVERE STORMS. MODEL
THICKNESSES ARE QUITE WARM TODAY AND SUPPORT HIGHS IN THE UPPER
80S...AND I HAVE WARMED TEMPS A FEW DEGREES ACROSS THE BOARD. MODEL
TIME HEIGHTS AND SOUNDINGS SHOW LESS LOW LEVEL MOISTURE TODAY WHICH
IS EXPECTED TO SUPPORT MORE BREAKS IN THE CU FIELD AND BETTER
INSOLATION. THIS STRONG HEATING UNDER A MID MAY SUN IS EXPECTED TO
RESULT IN AN UNCAPPED AND MODERATELY UNSTABLE AIRMASS.
HOWEVER...VARIOUS MODEL SOLUTIONS DEPICT A PERIOD OF NVA INTO AT
LEAST THE EARLY AFTERNOON...WHICH MAY DELAY CONVECTIVE INITIATION
INTO THE LATE AFTERNOON. I HAVE FAVORED A NAM LIKE POP TREND FOR THE
DAY WHICH RESULTS IN THINGS BEING DRY THROUGH MID AFTERNOON...AND
THEN CONVECTION FIRING ALONG THE SEA BREEZE AS WELL AS INTERIOR SE
GA. THIS CONVECTION IS EXPECTED TO THEN SPREAD EASTWARD INTO THE
EVENING REACHING FAR SOUTHERN SC THROUGH THE LATE EVENING. COVERAGE
SHOULD DIMINISH RATHER QUICKLY WITH THE LOSS OF HEATING.

REGARDING THE SEVERE POTENTIAL...MODEL SOUNDINGS SHOW 1500-2000 J/KG
OF CAPE WITH LOTS OF MID-LEVEL DRY AIR. THIS RESULTS IN DCAPES
AROUND 1000 J/KG WITH A WET BULB ZERO HEIGHT IN THE 9-10 KFT RANGE.
WITH 0-6 KM SHEAR AROUND 25 KTS...THE ATMOSPHERE APPEARS SUPPORTIVE
FOR THE THREAT OF ISOLATED SEVERE STORMS...WITH BOTH LARGE HAIL AND
DAMAGING WIND GUSTS POSSIBLE. WILL ADD A SEVERE MENTION TO THE HWO.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...ISOLATED TO SCATTERED SHOWERS/STORMS WILL DIMINISH THROUGH
THE EVENING WITH THE LOSS OF DAYTIME HEATING. LINGERING OUTFLOW
BOUNDARIES WILL LIKELY DETERMINE THE FAVORED AREAS FOR ISOLATED TO
SCATTERED COVERAGE THROUGH THE LATE EVENING. LOWS WILL BE SIMILAR TO
PREVIOUS NIGHT WITH MID TO UPPER 60S EXPECTED.

WEDNESDAY...THE PESKY TROUGH ALOFT THAT HAS BEEN LOCATED UPSTREAM
THE PAST SEVERAL DAYS...WILL FINALLY BEGIN TO MOVE INTO THE
SE...WHILE ITS ASSOCIATED WEAK SURFACE COLD FRONT WILL BE FOUND
ACROSS THE CWFA. A DEEP SW FLOW IN ADVANCE OF THESE FEATURES WILL
TRANSPORT PLENTIFUL MOISTURE INTO SOUTHERN SC AND SE GA...WITH PWATS
AS HIGH AS AROUND 1.5 INCHES. INSTABILITY WILL ALSO BE
SUFFICIENT...WITH LIFTED INDICES NEAR -4 OR -5 AND SBCAPES OF AT
LEAST 1500 J/KG. LAPSE RATES MIGHT BE A LITTLE WEAK...BUT VARIOUS
PERTURBATIONS WILL MOVE THROUGH WITHIN THE SW FLOW ALOFT TO ASSIST
IN FORCING. AND IF THE SUB-TROPICAL JET FOUND MOVING OUT OF THE GULF
OF MEXICO IS DISPLACED JUST A LITTLE FURTHER NORTH...IT WOULD PUT US
IN THE LEFT FRONT QUAD. ALL THESE FACTORS POINT
TOWARD

GIVEN THE NEARBY COLD FRONT...THE SEA BREEZE AND VARIOUS LOW LEVEL
CONVERGENT BOUNDARIES...IF ANY OF THESE COLLIDE/INTERACT WITH ONE
ANOTHER...THEN WE COULD BE LOOKING AT SOME ISOLATED STRONG OR SEVERE
T-STORMS. DCAPES ARE NEAR 800 J/KG AND THERE WILL BE SOME DRY MID
LEVEL AIR. THAT ALONG WITH 500 MB TEMPS NEAR -13C SUGGESTS THAT
WHERE THE STRONGEST UPDRAFTS OCCUR THAT WE MIGHT DEVELOP A FEW
MULTICELL CLUSTERS. IF SO...THEN LOCALLY DAMAGING WINDS/MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST TSTMS IN THE
AFTERNOON/EARLY EVENING. SLOW MOVING STORMS TOWARD THE EAST CAN ALSO
RESULT IN LOCALIZED FLOODING. ACTIVITY WILL BECOME SCATTERED DURING
THE LATE MORNING AND AFTERNOON...WITH 40-50 POPS TO OCCUR AREA WIDE.

WE/LL COME CLOSE TO THE LOW LEVEL THICKNESS FORECAST IN REGARDS TO
MAX TEMPS...WITH HIGHEST READINGS MAINLY IN THE MID AND UPPER 80S.

THURSDAY...THE AFOREMENTIONED TROUGH ALOFT WILL DRIFT TO THE SE
COAST BY LATE IN THE DAY...AS THE REMNANTS OF THE WEAK COLD
FRONT...BY NOW MORE A BAROCLINIC ZONE WILL ALSO PUSH TOWARD THE
COAST. MOISTURE THOUGH IS STILL PLENTIFUL WITH PWATS CLOSE TO 1.5
INCHES...AND THERE IS AMPLE INSTABILITY AND MESO-SCALE BOUNDARIES
SUCH AS THE SEA BREEZE FOR CONVECTION TO FORM ALONG. WE/LL MAINTAIN
SLIGHT CHANCE AND CHANCE POPS...HIGHEST SOUTH OF BEAUFORT. TEMPS
WILL AGAIN BE ABOVE SEASONAL NORMALS WITH 850 MB TEMPS NEAR 11-12C.

FRIDAY...MUCH DRIER AIR WORKS ITS WAY INTO THE AREA...AS STRONG HIGH
PRESSURE BUILDS FROM THE NORTH AND NE. THIS WILL BE PRECEDED BY A
LOW LEVEL CONVERGENCE BOUNDARY OR WIND SURGE...WHICH MAY BE
ACCOMPANIED BY A NARROW BAND OF SHOWERS. OTHERWISE...THE MAIN
BAROCLINIC ZONE WILL HAVE SHIFTED INTO OR JUST SOUTH OF OUR SOUTHERN
ZONES. WHILE THE NORTHERN AND CENTRAL ZONES WILL TURN OUT
RAINFREE...SLIGHT CHANCE AND CHANCE POPS ARE IN ORDER NEAR AND SOUTH
OF I-16 WHERE THE BEST LOW LEVEL CONVERGENCE AND GREATEST LINGERING
MOISTURE WILL BE FOUND. BREEZY CONDITIONS WILL IMPACT COASTAL AREAS
WITH SOME PACKING OF THE PRESSURE GRADIENT AROUND LARGE HIGH
PRESSURE MOVING THROUGH THE NE STATES. TEMPS WILL BE A TAD COOLER
WITH THE ONSHORE FLOW...BUT STILL NEAR OR SLIGHTLY ABOVE NORMAL
DURING THE DAYTIME...WITH NOTICEABLY COOLER CONDITIONS WELL INLAND
AT NIGHT WITH SOME UPPER 50S EXPECTED.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
THE PRIMARY NEAR TERM CONCERN IS THE POTENTIAL FOR STRATUS AND/OR
FOG AT KCHS AND KSAV. IT LOOKS LIKE THERE WILL BE ENOUGH LOW LEVEL
FLOW TO PREVENT FOG FORMATION THROUGH SUNRISE SO I HAVE NOT
INTRODUCED ANY REDUCED VISIBILITIES. STRATUS APPEARS MORE LIKELY
AND IS ALREADY DEVELOPING ACROSS AN AREA FROM BEAUFORT TO
WALTERBORO AND INTO THE MIDLANDS. THE CURRENT STRATUS LINES UP
WELL WITH AN AREA OF CLEAR SKIES NORTH OF THE DEBRIS CLOUDS FROM
DIMINISHING SHOWERS OVER SE GA. I HAVE ADDED IN A TEMPO GROUP FOR
MVFR CIGS AT KCHS...AND KEPT KSAV VFR.

THIS AFTERNOON...FORECAST CONCERNS SHIFT TO THE POTENTIAL FOR
THUNDERSTORM DEVELOPMENT. CURRENT THINKING IS THAT DEVELOPMENT
WILL BE DELAYED INTO THE MID/LATE AFTERNOON HOURS WITH THE BEST
COVERAGE OCCURRING IN AND AROUND THE KSAV AREA. THEREFORE...I HAVE
ADDED A PROB30 GROUP TO KSAV AND LEFT IT OUT AT KCHS FOR NOW.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO DIURNAL
SHRA/TSRA. VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND
SATURDAY.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
AHEAD OF A WEAK COLD FRONT...WITH WINDS OF 15 KTS OR LESS EXPECTED.
WAVE WATCH GUIDANCE CONTINUES TO INITIALIZE WITH SEAS HIGHER THAN
OBSERVED...SO I HAVE TAPERED THEM DOWNWARD TO SHOW 2-4 FT WITHIN 20
NM AND A SOLID 4 FT BEYOND.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE
WEEKEND...WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER
WINDS AND LARGER SEAS FRIDAY THROUGH SUNDAY. SCA/S SEEM ALMOST A
CERTAINTY DURING THAT TIME.

ALTHOUGH WATER TEMPS MIGHT STILL BE A LITTLE TOO LOW...GIVEN A
LIGHT WIND REGIME WITH AMPLE MOISTURE AND INSTABILITY...AND VARIOUS
LOW LEVEL CONVERGENT BOUNDARIES...WE WILL NEED TO BE ALERT FOR
POSSIBLE WATERSPOUT FORMATION THURSDAY MORNING.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL. WE WILL ADD MENTION TO THE
HAZARDOUS WEATHER OUTLOOK.

&&

.EQUIPMENT...
KCLX RADAR IS DOWN UNTIL FURTHER NOTICE DUE TO A WIDEBAND FAILURE/SIGNAL
PROCESSOR COMMS ERROR. EXPECTING IT TO BE BACK IN OPERATION BY
LATE MORNING OR EARLY AFTERNOON. USERS ARE DIRECTED TO THE
FOLLOWING SURROUNDING RADARS IN THE INTERIM...

KLTX...WILMINGTON
KCAE...COLUMBIA
KFFC...ATLANTA/PEACHTREE CITY
KJAX...JACKSONVILLE
KJGX...WARNER ROBBINS
KVAX...VALDOSTA

&&

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

&&

$$

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

000
FXUS62 KCAE 150914
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
514 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A NEARLY STATIONARY FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR
SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON. THE FRONT WILL
SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE INCREASED CHANCES
OF RAIN ACROSS THE EASTERN MIDLANDS ON WEDNESDAY BEFORE SHIFTING
TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION
THURSDAY AND PROVIDE DRY WEATHER THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH AND ANOTHER MID-
LEVEL SHORTWAVE TROUGH PLUS HEATING SUPPORTS SHOWERS AND
THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. USED THE HIGHER
GUIDANCE POPS BECAUSE OF THIS SUPPORT. LOW-LEVEL MOISTURE
ASSOCIATED WITH CONVERGENCE INTO THE SURFACE TROUGH WILL REMAIN
HIGH TODAY. UPPER-LEVEL MOISTURE WILL BE A LITTLE LESS COMPARED TO
THE PAST FEW DAYS. EXPECT THE DIMINISHED MOISTURE WILL LEAD TO
MORE HEATING AND INSTABILITY. THE MODELS INDICATE MODERATE TO
STRONG INSTABILITY THIS AFTERNOON SUPPORTING POSSIBLE DAMAGING
WIND AND HAIL WITH A FEW OF THE THUNDERSTORMS. USED THE GUIDANCE
CONSENSUS FOR THE TEMPERATURE FORECAST.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
EXPECT LINGERING CONVECTION THIS EVENING ACROSS THE FORECAST AREA
SUPPORTED BY UPPER IMPULSES MOVING THROUGH THE SOUTHWESTERLY FLOW
ALOFT. WILL MAINTAIN HIGH CHANCE POPS EARLY WITH DIMINISHING
CHANCES THROUGH THE OVERNIGHT HOURS AS THE ATMOSPHERE BECOMES MORE
STABLE. EXPECT PLENTY OF CONVECTIVE DEBRIS CLOUDS AND THIS SHOULD
LIMIT THE AMOUNT OF RADIATIONAL COOLING OVERNIGHT. MIN
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE LOWER TO MID 60S.

THE SURFACE BOUNDARY SHIFTS VERY SLOWLY EASTWARD ACROSS THE
FORECAST AREA ON WEDNESDAY AND WILL AGAIN PROVIDE A FOCUS FOR
CONVECTIVE DEVELOPMENT. A WEST TO EAST GRADIENT IN DEEPER MOISTURE
WILL EXIST ACROSS THE REGION ON WEDNESDAY WITH THE BEST MOISTURE
BEING FOCUS CLOSER TO THE COASTAL PLAIN AND EASTERN MIDLANDS. THE
ATMOSPHERE WILL DESTABILIZE WITH DAYTIME HEATING AIDED BY COOLING
500 MB TEMPERATURES (-13C). WILL CONTINUE WITH THE CHANCE FOR
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...WITH
THE HIGHEST POPS ACROSS THE EASTERN MIDLANDS WHERE BETTER MOISTURE
IS FORECAST AND IN THE VICINITY OF THE SLOW MOVING SURFACE
BOUNDARY. ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE BUT THE
COVERAGE IS NOT EXPECTED TO BE AS GREAT. TEMPERATURES ON WEDNESDAY
WILL GENERALLY BE IN THE LOWER TO MID 80S.

THE UPPER TROUGH AXIS FINALLY SHIFTS EAST ACROSS THE FORECAST AREA
WEDNESDAY NIGHT AND THURSDAY AND DRIER AIR WILL BUILD IN FROM THE
NORTHWEST AS SURFACE HIGH PRESSURE BUILDS IN BEHIND THE DEPARTED
SURFACE FRONT. DESPITE THE COOLER AND DRIER AIR BUILDING INTO THE
REGION...PLENTY OF SUNSHINE IS EXPECTED THURSDAY WHICH WILL OFFSET
ANY WEAK COLD ADVECTION AND TEMPERATURES SHOULD REMAIN SEASONABLE
IN THE LOWER 80S WITH LITTLE CHANCE OF RAIN.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT INDICATING
TROUGHING ALONG THE WEST COAST DURING THE EXTENDED PERIOD WHICH
WILL RESULT IN DOWNSTREAM RIDGING AND RISING UPPER HEIGHTS OVER
THE FORECAST AREA. DRY WEATHER IS EXPECTED THROUGH THIS PERIOD AS
HIGH PRESSURE AT THE SURFACE AND ALOFT PROVIDE A RELATIVELY STABLE
AND DRY ATMOSPHERE. TEMPERATURES DURING THE PERIOD WILL BE NEAR
NORMAL WITH HIGHS IN THE 80S AND LOWS IN THE 50S TO LOWER 60S.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
HIGH LOW-LEVEL MOISTURE WILL BRING WIDESPREAD IFR CEILINGS EARLY
THIS MORNING. HEATING AND MIXING WILL RESULT IN SOME IMPROVEMENT
LATER THIS MORNING. USED THE GFS LAMP FOR THE TIMING. HOWEVER...
CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH AND ANOTHER
MID-LEVEL SHORTWAVE TROUGH PLUS HEATING SUPPORTS THUNDERSTORMS...
ESPECIALLY DURING THE AFTERNOON. DID NOT INCLUDE THUNDERSTORMS IN
THE TERMINAL FORECAST BECAUSE OF TIMING UNCERTAINTY. STRONG
HEATING WITH COLD AIR ALOFT ASSOCIATED WITH THE UPPER TROUGH WILL
RESULT IN MODERATE TO STRONG INSTABILITY. ANY THUNDERSTORMS MAY
CONTAIN STRONG WIND AND HAIL.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
ASSOCIATED WITH THE SLOW MOVING FRONT MAY OCCUR THROUGH WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KCHS 150832
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
429 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A VERY WEAK COLD FRONT WILL LINGER IN THE AREA THROUGH EARLY
THURSDAY...BEFORE DISSIPATING IN THE NEARBY ATLANTIC. STRONG HIGH
PRESSURE WILL BUILD FROM THE NORTH AND NORTHEAST LATE IN THE WEEK
AND PERSIST ACROSS THE REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS MORNING...OTHER THAN AN ISOLATED SHOWER OR TWO ACROSS
EASTERN CHARLESTON COUNTY AND SCATTERED SHOWERS WELL
OFFSHORE...PRECIP HAS ENDED ACROSS THE FORECAST AREA. TEMPS ARE
CURRENTLY IN THE UPPER 60S TO LOW 70S...AND ENOUGH S TO SW FLOW
SHOULD STAY UP THROUGH THE REMAINDER OF THE NIGHT TO KEEP TEMPS FROM
FALLING MUCH FURTHER. SCATTERED TO OCCASIONALLY BROKEN STRATUS WILL
AFFECT PORTIONS OF THE AREA THROUGH SUNRISE BUT ISN/T LIKELY TO
BECOME WIDESPREAD. THE PERSISTENT LOW LEVEL FLOW IS EXPECTED TO KEEP
THE ATMOSPHERE MIXED ENOUGH TO PRECLUDE FOG DEVELOPMENT AS WELL.

TODAY...THE OVERALL SETUP IS VERY MUCH LIKE MONDAY. THE REGION WILL
BE IN A BAND OF SW FLOW ALOFT POSITIONED EAST OF A STAGNANT TROF
THAT STRETCHES FROM THE TN VALLEY TO EAST TX. AT THE SURFACE...THE
WEAK SURFACE LOW AND ILL-DEFINED COLD FRONT WILL MOVE SLIGHTLY
CLOSER TO THE FORECAST AREA THROUGH THE DAY. SO THE PRIMARY FORECAST
PROBLEM REVOLVES AROUND THE INITIATION AND COVERAGE OF DIURNAL
CONVECTION...AND THE POTENTIAL FOR STRONG/SEVERE STORMS. MODEL
THICKNESSES ARE QUITE WARM TODAY AND SUPPORT HIGHS IN THE UPPER
80S...AND I HAVE WARMED TEMPS A FEW DEGREES ACROSS THE BOARD. MODEL
TIME HEIGHTS AND SOUNDINGS SHOW LESS LOW LEVEL MOISTURE TODAY WHICH
IS EXPECTED TO SUPPORT MORE BREAKS IN THE CU FIELD AND BETTER
INSOLATION. THIS STRONG HEATING UNDER A MID MAY SUN IS EXPECTED TO
RESULT IN AN UNCAPPED AND MODERATELY UNSTABLE AIRMASS.
HOWEVER...VARIOUS MODEL SOLUTIONS DEPICT A PERIOD OF NVA INTO AT
LEAST THE EARLY AFTERNOON...WHICH MAY DELAY CONVECTIVE INITIATION
INTO THE LATE AFTERNOON. I HAVE FAVORED A NAM LIKE POP TREND FOR THE
DAY WHICH RESULTS IN THINGS BEING DRY THROUGH MID AFTERNOON...AND
THEN CONVECTION FIRING ALONG THE SEA BREEZE AS WELL AS INTERIOR SE
GA. THIS CONVECTION IS EXPECTED TO THEN SPREAD EASTWARD INTO THE
EVENING REACHING FAR SOUTHERN SC THROUGH THE LATE EVENING. COVERAGE
SHOULD DIMINISH RATHER QUICKLY WITH THE LOSS OF HEATING.

REGARDING THE SEVERE POTENTIAL...MODEL SOUNDINGS SHOW 1500-2000 J/KG
OF CAPE WITH LOTS OF MID-LEVEL DRY AIR. THIS RESULTS IN DCAPES
AROUND 1000 J/KG WITH A WET BULB ZERO HEIGHT IN THE 9-10 KFT RANGE.
WITH 0-6 KM SHEAR AROUND 25 KTS...THE ATMOSPHERE APPEARS SUPPORTIVE
FOR THE THREAT OF ISOLATED SEVERE STORMS...WITH BOTH LARGE HAIL AND
DAMAGING WIND GUSTS POSSIBLE. WILL ADD A SEVERE MENTION TO THE HWO.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...ISOLATED TO SCATTERED SHOWERS/STORMS WILL DIMINISH THROUGH
THE EVENING WITH THE LOSS OF DAYTIME HEATING. LINGERING OUTFLOW
BOUNDARIES WILL LIKELY DETERMINE THE FAVORED AREAS FOR ISOLATED TO
SCATTERED COVERAGE THROUGH THE LATE EVENING. LOWS WILL BE SIMILAR TO
PREVIOUS NIGHT WITH MID TO UPPER 60S EXPECTED.

WEDNESDAY...THE PESKY TROUGH ALOFT THAT HAS BEEN LOCATED UPSTREAM
THE PAST SEVERAL DAYS...WILL FINALLY BEGIN TO MOVE INTO THE
SE...WHILE ITS ASSOCIATED WEAK SURFACE COLD FRONT WILL BE FOUND
ACROSS THE CWFA. A DEEP SW FLOW IN ADVANCE OF THESE FEATURES WILL
TRANSPORT PLENTIFUL MOISTURE INTO SOUTHERN SC AND SE GA...WITH PWATS
AS HIGH AS AROUND 1.5 INCHES. INSTABILITY WILL ALSO BE
SUFFICIENT...WITH LIFTED INDICES NEAR -4 OR -5 AND SBCAPES OF AT
LEAST 1500 J/KG. LAPSE RATES MIGHT BE A LITTLE WEAK...BUT VARIOUS
PERTURBATIONS WILL MOVE THROUGH WITHIN THE SW FLOW ALOFT TO ASSIST
IN FORCING. AND IF THE SUB-TROPICAL JET FOUND MOVING OUT OF THE GULF
OF MEXICO IS DISPLACED JUST A LITTLE FURTHER NORTH...IT WOULD PUT US
IN THE LEFT FRONT QUAD. ALL THESE FACTORS POINT
TOWARD

GIVEN THE NEARBY COLD FRONT...THE SEA BREEZE AND VARIOUS LOW LEVEL
CONVERGENT BOUNDARIES...IF ANY OF THESE COLLIDE/INTERACT WITH ONE
ANOTHER...THEN WE COULD BE LOOKING AT SOME ISOLATED STRONG OR SEVERE
T-STORMS. DCAPES ARE NEAR 800 J/KG AND THERE WILL BE SOME DRY MID
LEVEL AIR. THAT ALONG WITH 500 MB TEMPS NEAR -13C SUGGESTS THAT
WHERE THE STRONGEST UPDRAFTS OCCUR THAT WE MIGHT DEVELOP A FEW
MULTICELL CLUSTERS. IF SO...THEN LOCALLY DAMAGING WINDS/MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST TSTMS IN THE
AFTERNOON/EARLY EVENING. SLOW MOVING STORMS TOWARD THE EAST CAN ALSO
RESULT IN LOCALIZED FLOODING. ACTIVITY WILL BECOME SCATTERED DURING
THE LATE MORNING AND AFTERNOON...WITH 40-50 POPS TO OCCUR AREA WIDE.

WE/LL COME CLOSE TO THE LOW LEVEL THICKNESS FORECAST IN REGARDS TO
MAX TEMPS...WITH HIGHEST READINGS MAINLY IN THE MID AND UPPER 80S.

THURSDAY...THE AFOREMENTIONED TROUGH ALOFT WILL DRIFT TO THE SE
COAST BY LATE IN THE DAY...AS THE REMNANTS OF THE WEAK COLD
FRONT...BY NOW MORE A BAROCLINIC ZONE WILL ALSO PUSH TOWARD THE
COAST. MOISTURE THOUGH IS STILL PLENTIFUL WITH PWATS CLOSE TO 1.5
INCHES...AND THERE IS AMPLE INSTABILITY AND MESO-SCALE BOUNDARIES
SUCH AS THE SEA BREEZE FOR CONVECTION TO FORM ALONG. WE/LL MAINTAIN
SLIGHT CHANCE AND CHANCE POPS...HIGHEST SOUTH OF BEAUFORT. TEMPS
WILL AGAIN BE ABOVE SEASONAL NORMALS WITH 850 MB TEMPS NEAR 11-12C.

FRIDAY...MUCH DRIER AIR WORKS ITS WAY INTO THE AREA...AS STRONG HIGH
PRESSURE BUILDS FROM THE NORTH AND NE. THIS WILL BE PRECEDED BY A
LOW LEVEL CONVERGENCE BOUNDARY OR WIND SURGE...WHICH MAY BE
ACCOMPANIED BY A NARROW BAND OF SHOWERS. OTHERWISE...THE MAIN
BAROCLINIC ZONE WILL HAVE SHIFTED INTO OR JUST SOUTH OF OUR SOUTHERN
ZONES. WHILE THE NORTHERN AND CENTRAL ZONES WILL TURN OUT
RAINFREE...SLIGHT CHANCE AND CHANCE POPS ARE IN ORDER NEAR AND SOUTH
OF I-16 WHERE THE BEST LOW LEVEL CONVERGENCE AND GREATEST LINGERING
MOISTURE WILL BE FOUND. BREEZY CONDITIONS WILL IMPACT COASTAL AREAS
WITH SOME PACKING OF THE PRESSURE GRADIENT AROUND LARGE HIGH
PRESSURE MOVING THROUGH THE NE STATES. TEMPS WILL BE A TAD COOLER
WITH THE ONSHORE FLOW...BUT STILL NEAR OR SLIGHTLY ABOVE NORMAL
DURING THE DAYTIME...WITH NOTICEABLY COOLER CONDITIONS WELL INLAND
AT NIGHT WITH SOME UPPER 50S EXPECTED.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PERIODS ARE STILL SOMEWHAT UNCERTAIN AT THIS TIME.
LATEST INDICATIONS ARE THAT A STRONG AND EXPANSIVE AREA OF SURFACE
HIGH PRESSURE IN THE NW ATLANTIC WILL EXTEND ACROSS THE LOCAL AREA
LATE IN THE WEEK INTO EARLY NEXT WEEK. MEANWHILE...FAR OFF THE COAST
NEAR 30 WEST THERE ARE STILL SOME INDICATIONS THAT A COLD CORE OR
HYBRID LOW WILL FORM AS A CLOSED LOW DEVELOPS ALOFT OVER OR NEAR THE
SE COAST.

IN REGARDS TO SENSIBLE WEATHER...AND PROVIDED ANY ATLANTIC LOW STAYS
FAR OFFSHORE...WE/RE LOOKING AT CONDITIONS GENERALLY DRIVEN BY LOW
LEVEL CONVERGENCE WITHIN THE CLOCKWISE FLOW AROUND THE NW ATLANTIC
RIDGE. THIS ALONG WITH A GRADUAL RETURN OF MOISTURE WILL CAUSE A DAY
TO DAY INCREASE IN SHOWERS AS THEY PROGRESS FURTHER NORTH EACH DAY.
SLIGHT CHANCE POPS WILL BE RESTRICTED TO SOUTH OF I-16 IN SE GA
SATURDAY...WITH SLIGHT CHANCE TO CHANCE POPS OVER EASTERN AND
SOUTHERN SECTIONS SUNDAY. FOR MONDAY AND TUESDAY WE/LL SHOW SLIGHT
CHANCE POPS ALL AREAS. TEMPS WILL AVERAGE CLOSE TO WHAT IS EXPECTED
FOR THAT TIME OF YEAR.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
THE PRIMARY NEAR TERM CONCERN IS THE POTENTIAL FOR STRATUS AND/OR
FOG AT KCHS AND KSAV. IT LOOKS LIKE THERE WILL BE ENOUGH LOW LEVEL
FLOW TO PREVENT FOG FORMATION THROUGH SUNRISE SO I HAVE NOT
INTRODUCED ANY REDUCED VISIBILITIES. STRATUS APPEARS MORE LIKELY
AND IS ALREADY DEVELOPING ACROSS AN AREA FROM BEAUFORT TO
WALTERBORO AND INTO THE MIDLANDS. THE CURRENT STRATUS LINES UP
WELL WITH AN AREA OF CLEAR SKIES NORTH OF THE DEBRIS CLOUDS FROM
DIMINISHING SHOWERS OVER SE GA. I HAVE ADDED IN A TEMPO GROUP FOR
MVFR CIGS AT KCHS...AND KEPT KSAV VFR.

THIS AFTERNOON...FORECAST CONCERNS SHIFT TO THE POTENTIAL FOR
THUNDERSTORM DEVELOPMENT. CURRENT THINKING IS THAT DEVELOPMENT
WILL BE DELAYED INTO THE MID/LATE AFTERNOON HOURS WITH THE BEST
COVERAGE OCCURRING IN AND AROUND THE KSAV AREA. THEREFORE...I HAVE
ADDED A PROB30 GROUP TO KSAV AND LEFT IT OUT AT KCHS FOR NOW.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO DIURNAL
SHRA/TSRA. VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND
SATURDAY.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
AHEAD OF A WEAK COLD FRONT...WITH WINDS OF 15 KTS OR LESS EXPECTED.
WAVE WATCH GUIDANCE CONTINUES TO INITIALIZE WITH SEAS HIGHER THAN
OBSERVED...SO I HAVE TAPERED THEM DOWNWARD TO SHOW 2-4 FT WITHIN 20
NM AND A SOLID 4 FT BEYOND.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE
WEEKEND...WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER
WINDS AND LARGER SEAS FRIDAY THROUGH SUNDAY. SCA/S SEEM ALMOST A
CERTAINTY DURING THAT TIME.

ALTHOUGH WATER TEMPS MIGHT STILL BE A LITTLE TOO LOW...GIVEN A
LIGHT WIND REGIME WITH AMPLE MOISTURE AND INSTABILITY...AND VARIOUS
LOW LEVEL CONVERGENT BOUNDARIES...WE WILL NEED TO BE ALERT FOR
POSSIBLE WATERSPOUT FORMATION THURSDAY MORNING.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL. WE WILL ADD MENTION TO THE
HAZARDOUS WEATHER OUTLOOK.

&&

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

&&

$$

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

000
FXUS62 KCHS 150829
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
429 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A VERY WEAK COLD FRONT WILL LINGER IN THE AREA THROUGH EARLY
THURSDAY...BEFORE DISSIPATING IN THE NEARBY ATLANTIC. STRONG HIGH
PRESSURE WILL BUILD FROM THE NORTH AND NORTHEAST LATE IN THE WEEK
AND PERSIST ACROSS THE REGION INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS MORNING...OTHER THAN AN ISOLATED SHOWER OR TWO ACROSS
EASTERN CHARLESTON COUNTY AND SCATTERED SHOWERS WELL
OFFSHORE...PRECIP HAS ENDED ACROSS THE FORECAST AREA. TEMPS ARE
CURRENTLY IN THE UPPER 60S TO LOW 70S...AND ENOUGH S TO SW FLOW
SHOULD STAY UP THROUGH THE REMAINDER OF THE NIGHT TO KEEP TEMPS FROM
FALLING MUCH FURTHER. SCATTERED TO OCCASIONALLY BROKEN STRATUS WILL
AFFECT PORTIONS OF THE AREA THROUGH SUNRISE BUT ISN/T LIKELY TO
BECOME WIDESPREAD. THE PERSISTENT LOW LEVEL FLOW IS EXPECTED TO KEEP
THE ATMOSPHERE MIXED ENOUGH TO PRECLUDE FOG DEVELOPMENT AS WELL.

TODAY...THE OVERALL SETUP IS VERY MUCH LIKE MONDAY. THE REGION WILL
BE IN A BAND OF SW FLOW ALOFT POSITIONED EAST OF A STAGNANT TROF
THAT STRETCHES FROM THE TN VALLEY TO EAST TX. AT THE SURFACE...THE
WEAK SURFACE LOW AND ILL-DEFINED COLD FRONT WILL MOVE SLIGHTLY
CLOSER TO THE FORECAST AREA THROUGH THE DAY. SO THE PRIMARY FORECAST
PROBLEM REVOLVES AROUND THE INITIATION AND COVERAGE OF DIURNAL
CONVECTION...AND THE POTENTIAL FOR STRONG/SEVERE STORMS. MODEL
THICKNESSES ARE QUITE WARM TODAY AND SUPPORT HIGHS IN THE UPPER
80S...AND I HAVE WARMED TEMPS A FEW DEGREES ACROSS THE BOARD. MODEL
TIME HEIGHTS AND SOUNDINGS SHOW LESS LOW LEVEL MOISTURE TODAY WHICH
IS EXPECTED TO SUPPORT MORE BREAKS IN THE CU FIELD AND BETTER
INSOLATION. THIS STRONG HEATING UNDER A MID MAY SUN IS EXPECTED TO
RESULT IN AN UNCAPPED AND MODERATELY UNSTABLE AIRMASS.
HOWEVER...VARIOUS MODEL SOLUTIONS DEPICT A PERIOD OF NVA INTO AT
LEAST THE EARLY AFTERNOON...WHICH MAY DELAY CONVECTIVE INITIATION
INTO THE LATE AFTERNOON. I HAVE FAVORED A NAM LIKE POP TREND FOR THE
DAY WHICH RESULTS IN THINGS BEING DRY THROUGH MID AFTERNOON...AND
THEN CONVECTION FIRING ALONG THE SEA BREEZE AS WELL AS INTERIOR SE
GA. THIS CONVECTION IS EXPECTED TO THEN SPREAD EASTWARD INTO THE
EVENING REACHING FAR SOUTHERN SC THROUGH THE LATE EVENING. COVERAGE
SHOULD DIMINISH RATHER QUICKLY WITH THE LOSS OF HEATING.

REGARDING THE SEVERE POTENTIAL...MODEL SOUNDINGS SHOW 1500-2000 J/KG
OF CAPE WITH LOTS OF MID-LEVEL DRY AIR. THIS RESULTS IN DCAPES AROUND
1000 J/KG WITH A WET BULB ZERO HEIGHT IN THE 9-10 KFT RANGE. WITH
0-6 KM SHEAR AROUND 25 KTS...THE ATMOSPHERE APPEARS SUPPORTIVE FOR
THE THREAT OF ISOLATED SEVERE STORMS...WITH BOTH LARGE HAIL AND
DAMAGING WIND GUSTS POSSIBLE. WILL ADD A SEVERE MENTION TO THE HWO.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...ISOLATED TO SCATTERED SHOWERS/STORMS WILL DIMINISH THROUGH
THE EVENING WITH THE LOSS OF DAYTIME HEATING. LINGERING OUTFLOW
BOUNDARIES WILL LIKELY DETERMINE THE FAVORED AREAS FOR ISOLATED TO
SCATTERED COVERAGE THROUGH THE LATE EVENING. LOWS WILL BE SIMILAR TO
PREVIOUS NIGHT WITH MID TO UPPER 60S EXPECTED.

WEDNESDAY...THE PESKY TROUGH ALOFT THAT HAS BEEN LOCATED UPSTREAM
THE PAST SEVERAL DAYS...WILL FINALLY BEGIN TO MOVE INTO THE
SE...WHILE ITS ASSOCIATED WEAK SURFACE COLD FRONT WILL BE FOUND
ACROSS THE CWFA. A DEEP SW FLOW IN ADVANCE OF THESE FEATURES WILL
TRANSPORT PLENTIFUL MOISTURE INTO SOUTHERN SC AND SE GA...WITH PWATS
AS HIGH AS AROUND 1.5 INCHES. INSTABILITY WILL ALSO BE
SUFFICIENT...WITH LIFTED INDICES NEAR -4 OR -5 AND SBCAPES OF AT
LEAST 1500 J/KG. LAPSE RATES MIGHT BE A LITTLE WEAK...BUT VARIOUS
PERTURBATIONS WILL MOVE THROUGH WITHIN THE SW FLOW ALOFT TO ASSIST
IN FORCING. AND IF THE SUB-TROPICAL JET FOUND MOVING OUT OF THE GULF
OF MEXICO IS DISPLACED JUST A LITTLE FURTHER NORTH...IT WOULD PUT US
IN THE LEFT FRONT QUAD. ALL THESE FACTORS POINT
TOWARD

GIVEN THE NEARBY COLD FRONT...THE SEA BREEZE AND VARIOUS LOW LEVEL
CONVERGENT BOUNDARIES...IF ANY OF THESE COLLIDE/INTERACT WITH ONE
ANOTHER...THEN WE COULD BE LOOKING AT SOME ISOLATED STRONG OR SEVERE
T-STORMS. DCAPES ARE NEAR 800 J/KG AND THERE WILL BE SOME DRY MID
LEVEL AIR. THAT ALONG WITH 500 MB TEMPS NEAR -13C SUGGESTS THAT
WHERE THE STRONGEST UPDRAFTS OCCUR THAT WE MIGHT DEVELOP A FEW
MULTICELL CLUSTERS. IF SO...THEN LOCALLY DAMAGING WINDS/MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST TSTMS IN THE
AFTERNOON/EARLY EVENING. SLOW MOVING STORMS TOWARD THE EAST CAN ALSO
RESULT IN LOCALIZED FLOODING. ACTIVITY WILL BECOME SCATTERED DURING
THE LATE MORNING AND AFTERNOON...WITH 40-50 POPS TO OCCUR AREA WIDE.

WE/LL COME CLOSE TO THE LOW LEVEL THICKNESS FORECAST IN REGARDS TO
MAX TEMPS...WITH HIGHEST READINGS MAINLY IN THE MID AND UPPER 80S.

THURSDAY...THE AFOREMENTIONED TROUGH ALOFT WILL DRIFT TO THE SE
COAST BY LATE IN THE DAY...AS THE REMNANTS OF THE WEAK COLD
FRONT...BY NOW MORE A BAROCLINIC ZONE WILL ALSO PUSH TOWARD THE
COAST. MOISTURE THOUGH IS STILL PLENTIFUL WITH PWATS CLOSE TO 1.5
INCHES...AND THERE IS AMPLE INSTABILITY AND MESO-SCALE BOUNDARIES
SUCH AS THE SEA BREEZE FOR CONVECTION TO FORM ALONG. WE/LL MAINTAIN
SLIGHT CHANCE AND CHANCE POPS...HIGHEST SOUTH OF BEAUFORT. TEMPS
WILL AGAIN BE ABOVE SEASONAL NORMALS WITH 850 MB TEMPS NEAR 11-12C.

FRIDAY...MUCH DRIER AIR WORKS ITS WAY INTO THE AREA...AS STRONG HIGH
PRESSURE BUILDS FROM THE NORTH AND NE. THIS WILL BE PRECEDED BY A
LOW LEVEL CONVERGENCE BOUNDARY OR WIND SURGE...WHICH MAY BE
ACCOMPANIED BY A NARROW BAND OF SHOWERS. OTHERWISE...THE MAIN
BAROCLINIC ZONE WILL HAVE SHIFTED INTO OR JUST SOUTH OF OUR SOUTHERN
ZONES. WHILE THE NORTHERN AND CENTRAL ZONES WILL TURN OUT
RAINFREE...SLIGHT CHANCE AND CHANCE POPS ARE IN ORDER NEAR AND SOUTH
OF I-16 WHERE THE BEST LOW LEVEL CONVERGENCE AND GREATEST LINGERING
MOISTURE WILL BE FOUND. BREEZY CONDITIONS WILL IMPACT COASTAL AREAS
WITH SOME PACKING OF THE PRESSURE GRADIENT AROUND LARGE HIGH
PRESSURE MOVING THROUGH THE NE STATES. TEMPS WILL BE A TAD COOLER
WITH THE ONSHORE FLOW...BUT STILL NEAR OR SLIGHTLY ABOVE NORMAL
DURING THE DAYTIME...WITH NOTICEABLY COOLER CONDITIONS WELL INLAND
AT NIGHT WITH SOME UPPER 50S EXPECTED.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
WEDNESDAY...THE PESKY TROUGH ALOFT THAT HAS BEEN LOCATED UPSTREAM
THE PAST SEVERAL DAYS...WILL FINALLY BEGIN TO MOVE INTO THE
SE...WHILE ITS ASSOCIATED WEAK SURFACE COLD FRONT WILL BE FOUND
ACROSS THE CWFA. A DEEP SW FLOW IN ADVANCE OF THESE FEATURES WILL
TRANSPORT PLENTIFUL MOISTURE INTO SOUTHERN SC AND SE GA...WITH PWATS
AS HIGH AS AROUND 1.5 INCHES. INSTABILITY WILL ALSO BE
SUFFICIENT...WITH LIFTED INDICES NEAR -4 OR -5 AND SBCAPES OF AT
LEAST 1500 J/KG. LAPSE RATES MIGHT BE A LITTLE WEAK...BUT VARIOUS
PERTURBATIONS WILL MOVE THROUGH WITHIN THE SW FLOW ALOFT TO ASSIST
IN FORCING. AND IF THE SUB-TROPICAL JET FOUND MOVING OUT OF THE GULF
OF MEXICO IS DISPLACED JUST A LITTLE FURTHER NORTH...IT WOULD PUT US
IN THE LEFT FRONT QUAD. ALL THESE FACTORS POINT
TOWARD

GIVEN THE NEARBY COLD FRONT...THE SEA BREEZE AND VARIOUS LOW LEVEL
CONVERGENT BOUNDARIES...IF ANY OF THESE COLLIDE/INTERACT WITH ONE
ANOTHER...THEN WE COULD BE LOOKING AT SOME ISOLATED STRONG OR SEVERE
T-STORMS. DCAPES ARE NEAR 800 J/KG AND THERE WILL BE SOME DRY MID
LEVEL AIR. THAT ALONG WITH 500 MB TEMPS NEAR -13C SUGGESTS THAT
WHERE THE STRONGEST UPDRAFTS OCCUR THAT WE MIGHT DEVELOP A FEW
MULTICELL CLUSTERS. IF SO...THEN LOCALLY DAMAGING WINDS/MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST TSTMS IN THE
AFTERNOON/EARLY EVENING. SLOW MOVING STORMS TOWARD THE EAST CAN ALSO
RESULT IN LOCALIZED FLOODING. ACTIVITY WILL BECOME SCATTERED DURING
THE LATE MORNING AND AFTERNOON...WITH 40-50 POPS TO OCCUR AREA WIDE.

WE/LL COME CLOSE TO THE LOW LEVEL THICKNESS FORECAST IN REGARDS TO
MAX TEMPS...WITH HIGHEST READINGS MAINLY IN THE MID AND UPPER 80S.

THURSDAY...THE AFOREMENTIONED TROUGH ALOFT WILL DRIFT TO THE SE
COAST BY LATE IN THE DAY...AS THE REMNANTS OF THE WEAK COLD
FRONT...BY NOW MORE A BAROCLINIC ZONE WILL ALSO PUSH TOWARD THE
COAST. MOISTURE THOUGH IS STILL PLENTIFUL WITH PWATS CLOSE TO 1.5
INCHES...AND THERE IS AMPLE INSTABILITY AND MESO-SCALE BOUNDARIES
SUCH AS THE SEA BREEZE FOR CONVECTION TO FORM ALONG. WE/LL MAINTAIN
SLIGHT CHANCE AND CHANCE POPS...HIGHEST SOUTH OF BEAUFORT. TEMPS
WILL AGAIN BE ABOVE SEASONAL NORMALS WITH 850 MB TEMPS NEAR 11-12C.

FRIDAY...MUCH DRIER AIR WORKS ITS WAY INTO THE AREA...AS STRONG HIGH
PRESSURE BUILDS FROM THE NORTH AND NE. THIS WILL BE PRECEDED BY A
LOW LEVEL CONVERGENCE BOUNDARY OR WIND SURGE...WHICH MAY BE
ACCOMPANIED BY A NARROW BAND OF SHOWERS. OTHERWISE...THE MAIN
BAROCLINIC ZONE WILL HAVE SHIFTED INTO OR JUST SOUTH OF OUR SOUTHERN
ZONES. WHILE THE NORTHERN AND CENTRAL ZONES WILL TURN OUT
RAINFREE...SLIGHT CHANCE AND CHANCE POPS ARE IN ORDER NEAR AND SOUTH
OF I-16 WHERE THE BEST LOW LEVEL CONVERGENCE AND GREATEST LINGERING
MOISTURE WILL BE FOUND. BREEZY CONDITIONS WILL IMPACT COASTAL AREAS
WITH SOME PACKING OF THE PRESSURE GRADIENT AROUND LARGE HIGH
PRESSURE MOVING THROUGH THE NE STATES. TEMPS WILL BE A TAD COOLER
WITH THE ONSHORE FLOW...BUT STILL NEAR OR SLIGHTLY ABOVE NORMAL
DURING THE DAYTIME...WITH NOTICEABLY COOLER CONDITIONS WELL INLAND
AT NIGHT WITH SOME UPPER 50S EXPECTED.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
THE PRIMARY NEAR TERM CONCERN IS THE POTENTIAL FOR STRATUS AND/OR
FOG AT KCHS AND KSAV. IT LOOKS LIKE THERE WILL BE ENOUGH LOW LEVEL
FLOW TO PREVENT FOG FORMATION THROUGH SUNRISE SO I HAVE NOT
INTRODUCED ANY REDUCED VISIBILITIES. STRATUS APPEARS MORE LIKELY
AND IS ALREADY DEVELOPING ACROSS AN AREA FROM BEAUFORT TO
WALTERBORO AND INTO THE MIDLANDS. THE CURRENT STRATUS LINES UP
WELL WITH AN AREA OF CLEAR SKIES NORTH OF THE DEBRIS CLOUDS FROM
DIMINISHING SHOWERS OVER SE GA. I HAVE ADDED IN A TEMPO GROUP FOR
MVFR CIGS AT KCHS...AND KEPT KSAV VFR.

THIS AFTERNOON...FORECAST CONCERNS SHIFT TO THE POTENTIAL FOR
THUNDERSTORM DEVELOPMENT. CURRENT THINKING IS THAT DEVELOPMENT
WILL BE DELAYED INTO THE MID/LATE AFTERNOON HOURS WITH THE BEST
COVERAGE OCCURRING IN AND AROUND THE KSAV AREA. THEREFORE...I HAVE
ADDED A PROB30 GROUP TO KSAV AND LEFT IT OUT AT KCHS FOR NOW.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO DIURNAL
SHRA/TSRA. VFR CONDITIONS WITH GUSTY WINDS WILL OCCUR FRIDAY AND
SATURDAY.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH
TONIGHT. THE LOCAL WATERS WILL REMAIN IN AN AREA OF S TO SW FLOW
AHEAD OF A WEAK COLD FRONT...WITH WINDS OF 15 KTS OR LESS EXPECTED.
WAVE WATCH GUIDANCE CONTINUES TO INITIALIZE WITH SEAS HIGHER THAN
OBSERVED...SO I HAVE TAPERED THEM DOWNWARD TO SHOW 2-4 FT WITHIN 20
NM AND A SOLID 4 FT BEYOND.

OUTSIDE OF ISOLATED TO SCATTERED CONVECTION...WIND AND SEA
CONDITIONS ACROSS THE MARINE AREA WILL BE SOMEWHAT QUIET WEDNESDAY
THROUGH THURSDAY. HOWEVER...CONDITIONS WILL CHANGE FOR THE WORSE ON
FRIDAY...AS STRONG HIGH PRESSURE BUILDS FROM THE NORTH AND NE. THAT
HIGH WILL THEN PERSIST OVER THE MARINE AREA THROUGH THE
WEEKEND...WITH A PINCHING OF THE PRESSURE GRADIENT TO CAUSE HIGHER
WINDS AND LARGER SEAS FRIDAY THROUGH SUNDAY. SCA/S SEEM ALMOST A
CERTAINTY DURING THAT TIME.

ALTHOUGH WATER TEMPS MIGHT STILL BE A LITTLE TOO LOW...GIVEN A
LIGHT WIND REGIME WITH AMPLE MOISTURE AND INSTABILITY...AND VARIOUS
LOW LEVEL CONVERGENT BOUNDARIES...WE WILL NEED TO BE ALERT FOR
POSSIBLE WATERSPOUT FORMATION THURSDAY MORNING.

RIP CURRENTS...AN ELEVATED RISK OF RIP CURRENTS APPEARS LIKELY AT
THE BEACHES FRIDAY THROUGH MONDAY...WITH A PERSISTENT AND AT LEAST A
MODERATE NE AND EAST WIND TO PREVAIL. WE WILL ADD MENTION TO THE
HAZARDOUS WEATHER OUTLOOK.

&&

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

&&

$$

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

000
FXUS62 KFFC 150811
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
411 AM EDT TUE MAY 15 2012

.SHORT TERM /TODAY THROUGH WEDNESDAY/...
CWA STILL REMAINS ON THE EASTERN SIDE OF THE UPPER LEVEL TROUGH AND
THIS TROUGHING PATTERN WILL REMAIN A FEATURE THROUGH THE SHORT TERM.
ALTHOUGH COLD FRONT HAS ALREADY MOVED INTO EAST CENTRAL GA...THE
WHOLE CWA WILL REMAIN SUSCEPTIBLE TO SUMMERLIKE SHOWERS AND
THUNDERSTORMS THROUGH THE SHORT TERM WITH THE UPPER LEVEL TROUGH.

FOR TODAY...THE SFC FRONT IS EXPECTED TO REMAIN ACROSS EASTERN
GEORGIA. THIS MAY HELP PROVIDE A FOCUS FOR AFTERNOON DEVELOPMENT AND
HAVE SHOWN BEST CHANCE OF SHOWERS AND THUNDERSTORMS FOR TODAY ACROSS
THE EASTERN HALF OF THE CWA. WITH GFS AND NAM MUCAPE VALUES NEAR
1500 J/KG FOR THE AFTERNOON AND NO SHEAR...CANNOT RULE OUT AN
ISOLATED STRONG STORM...BUT NOT EXPECTING SEVERE STORMS. SHOWERS AND
THUNDERSTORMS WILL DECREASE IN COVERAGE OVERNIGHT. FOR WEDNESDAY...
THE FRONT WILL SINK INTO SOUTH GEORGIA BUT WE WILL STILL SEE A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN AS THE TROUGHING
PATTERN ALOFT CONTINUES AND A SHORTWAVE SWINGS THROUGH NORTH
GEORGIA.

WITH MOSTLY SUNNY TO PARTY SUNNY SKIES EXPECTED AGAIN TODAY...LEANED
TOWARD MAV TEMPS /WARMER GUIDANCE/ FOR MAX TEMPS THIS AFTERNOON.
REST OF SHORT TERM TEMPS ARE CLOSE TO A MAV/MET BLEND.

11


.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
LATEST GFS RUN A TAF SLOWER THAN PREVIOUS WITH AXIS OF UPPER TROF
SWINGING EAST OF THE COUNTY WARNING AREA AND UPPER RIDGE BUILDING
IN BEHIND IT. GFS NOW INDICATING A WEAK BOUNDARY APPROACHING THE
TENNESSEE VALLEY THURDAY WITH SOME DEEPER MOISTURE SPREADING INTO
EXTREME NORTHERN COUNTIES. MODELS HOLD ON TO REMNANTS OF WEAK
BOUNDARY SOMEWHERE NEAR THE TN/WRN NC BORDER THURSDAY NIGHT BEFORE
WASHING IT FRIDAY AS HIGH PRESSURE WEDGES DOWN THE APPALACHIANS
AND REMAIN DOMINANT OVER OUR AREA THROUGH THE WEEKEND. ECMWF MOST
AGGRESSIVE WITH SHOWING A WEAK COASTAL LOW FORMING NEAR THE
SOUTHEAST COAST OVER THE WEEKEND...BUT BOTH ECMWF AND GFS SIMILAR
WITH KEEPING BULK OF MOISTURE ASSOCIATED WITH THIS FEATURE EAST
AND SOUTH OF OUR AREA. MAY BE GETTING INTO BETTER CHANCES FOR
PRECIP MONDAY/TUESDAY WITH EXTENDED PROGS INDICATING A FRONTAL
BOUNDARY DRIFTING SOUTHEAST FROM THE OHIO/TENNESSEE VALLEY REGION.

49


&&

.AVIATION...
06Z UPDATE...
PRECIP HAS ENDED ACROSS MOST OF THE AREA AND EXPECT THIS LULL TO
CONTINUE THROUGH LATE THIS MORNING. MAIN CONCERN THIS MORNING WILL
BE LOW CLOUDS AND FOG. PLENTY OF LOW LEVEL MOISTURE TO SEE IFR TO
MVFR CONDITIONS THIS MORNING BUT CHALLENGE IS TIMING AND JUST HOW
LOW THESE CONDITIONS WILL BECOME. CHANCE OF THUNDERSTORMS AT THE
TAF SITES THIS AFTERNOON...ENOUGH TO WARRANT THE CONTINUATION OF
THE PROB 30 AT ALL SITES BUT CSG. WINDS WILL REMAIN WEST TO
NORTHWEST TODAY.

//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ON WIND. HIGH CONFIDENCE ON CIG HEIGHT AND VSBYS
EXCEPT LOW CONFIDENCE FROM 10Z TO 15Z. LOW CONFIDENCE ON THUNDER
OCCURRING AT THE AIRPORT THIS AFTERNOON.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          83  62  84  59 /  30  30  20  10
ATLANTA         81  63  82  62 /  20  20  20  10
BLAIRSVILLE     77  55  80  54 /  30  30  20  10
CARTERSVILLE    81  57  84  54 /  20  20  10  10
COLUMBUS        85  64  86  61 /  20  20  20  10
GAINESVILLE     80  61  81  60 /  30  30  20  10
MACON           86  61  85  59 /  30  30  20  10
ROME            83  59  84  56 /  20  20  10  10
PEACHTREE CITY  82  57  83  55 /  20  20  20  10
VIDALIA         84  66  85  64 /  30  30  30  10

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS62 KCAE 150706
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
306 AM EDT TUE MAY 15 2012

.SYNOPSIS...

A NEARLY STATIONARY FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR
SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON. THE FRONT WILL
SLOWLY PUSH EASTWARD TONIGHT BUT AGAIN PROVIDE INCREASED CHANCES
OF RAIN ACROSS THE EASTERN MIDLANDS ON WEDNESDAY BEFORE SHIFTING
TO THE COAST. SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION
THURSDAY AND PROVIDE DRY WEATHER THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...

REST OF TONIGHT...CONVERGENCE ASSOCIATED WITH A BOUNDARY WAS
SUPPORTING SHOWERS AND THUNDERSTORMS IN THE NORTH PART OF THE
FORECAST AREA EARLY THIS MORNING. SOME TRAINING WAS OCCURRING AND
HEAVY RAINFALL MAY OCCUR. ELSEWHERE...CONVERGENCE WAS WEAK AND
RADAR TRENDS SUPPORTED LOW POPS. EXPECT LOWS MAINLY IN THE MID
60S.

TODAY...CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH AND ANOTHER
MID-LEVEL SHORTWAVE TROUGH PLUS HEATING SUPPORTS SHOWERS AND
THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. USED THE HIGHER
GUIDANCE POPS BECAUSE OF THIS SUPPORT. LOW-LEVEL MOISTURE ASSOCIATED
WITH CONVERGENCE INTO THE SURFACE TROUGH WILL REMAIN HIGH TODAY.
UPPER-LEVEL MOISTURE WILL BE A LITTLE LESS COMPARED TO THE PAST FEW
DAYS. EXPECT THE DIMINISHED MOISTURE WILL LEAD TO MORE HEATING AND
INSTABILITY. THE MODELS INDICATE MODERATE TO STRONG INSTABILITY THIS
AFTERNOON SUPPORTING POSSIBLE DAMAGING WIND AND HAIL WITH A FEW OF
THE THUNDERSTORMS. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FORECAST.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...

EXPECT LINGERING CONVECTION THIS EVENING ACROSS THE FORECAST AREA
SUPPORTED BY UPPER IMPULSES MOVING THROUGH THE SOUTHWESTERLY FLOW
ALOFT. WILL MAINTAIN HIGH CHANCE POPS EARLY WITH DIMINISHING
CHANCES THROUGH THE OVERNIGHT HOURS AS THE ATMOSPHERE BECOMES MORE
STABLE. EXPECT PLENTY OF CONVECTIVE DEBRIS CLOUDS AND THIS SHOULD
LIMIT THE AMOUNT OF RADIATIONAL COOLING OVERNIGHT. MIN
TEMPERATURES SHOULD REMAIN ABOVE NORMAL IN THE LOWER TO MID 60S.

THE SURFACE BOUNDARY SHIFTS VERY SLOWLY EASTWARD ACROSS THE
FORECAST AREA ON WEDNESDAY AND WILL AGAIN PROVIDE A FOCUS FOR
CONVECTIVE DEVELOPMENT. A WEST TO EAST GRADIENT IN DEEPER MOISTURE
WILL EXIST ACROSS THE REGION ON WEDNESDAY WITH THE BEST MOISTURE
BEING FOCUS CLOSER TO THE COASTAL PLAIN AND EASTERN MIDLANDS. THE
ATMOSPHERE WILL DESTABILIZE WITH DAYTIME HEATING AIDED BY COOLING
500 MB TEMPERATURES (-13C). WILL CONTINUE WITH THE CHANCE FOR
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...WITH
THE HIGHEST POPS ACROSS THE EASTERN MIDLANDS WHERE BETTER MOISTURE
IS FORECAST AND IN THE VICINITY OF THE SLOW MOVING SURFACE
BOUNDARY. ISOLATED SEVERE THUNDERSTORMS WILL BE POSSIBLE BUT THE
COVERAGE IS NOT EXPECTED TO BE AS GREAT. TEMPERATURES ON WEDNESDAY
WILL GENERALLY BE IN THE LOWER TO MID 80S.

THE UPPER TROUGH AXIS FINALLY SHIFTS EAST ACROSS THE FORECAST AREA
WEDNESDAY NIGHT AND THURSDAY AND DRIER AIR WILL BUILD IN FROM THE
NORTHWEST AS SURFACE HIGH PRESSURE BUILDS IN BEHIND THE DEPARTED
SURFACE FRONT. DESPITE THE COOLER AND DRIER AIR BUILDING INTO THE
REGION...PLENTY OF SUNSHINE IS EXPECTED THURSDAY WHICH WILL OFFSET
ANY WEAK COLD ADVECTION AND TEMPERATURES SHOULD REMAIN SEASONABLE
IN THE LOWER 80S WITH LITTLE CHANCE OF RAIN.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...

MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT INDICATING
TROUGHING ALONG THE WEST COAST DURING THE EXTENDED PERIOD WHICH
WILL RESULT IN DOWNSTREAM RIDGING AND RISING UPPER HEIGHTS OVER
THE FORECAST AREA. DRY WEATHER IS EXPECTED THROUGH THIS PERIOD AS
HIGH PRESSURE AT THE SURFACE AND ALOFT PROVIDE A RELATIVELY STABLE
AND DRY ATMOSPHERE. TEMPERATURES DURING THE PERIOD WILL BE NEAR
NORMAL WITH HIGHS IN THE 80S AND LOWS IN THE 50S TO LOWER 60S.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...

HIGH LOW-LEVEL MOISTURE WILL BRING WIDESPREAD IFR CEILINGS EARLY
THIS MORNING. HEATING AND MIXING WILL RESULT IN SOME IMPROVEMENT
LATER THIS MORNING. USED THE GFS LAMP FOR THE TIMING. HOWEVER...
CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH AND ANOTHER
MID-LEVEL SHORTWAVE TROUGH PLUS HEATING SUPPORTS THUNDERSTORMS...
ESPECIALLY DURING THE AFTERNOON. DID NOT INCLUDE THUNDERSTORMS IN
THE TERMINAL FORECAST BECAUSE OF TIMING UNCERTAINTY. STRONG
HEATING WITH COLD AIR ALOFT ASSOCIATED WITH THE UPPER TROUGH WILL
RESULT IN MODERATE TO STRONG INSTABILITY. ANY THUNDERSTORMS MAY
CONTAIN STRONG WIND AND HAIL.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
ASSOCIATED WITH THE SLOW MOVING FRONT MAY OCCUR THROUGH WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KCHS 150602
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
202 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A BROAD AND WEAK AREA OF LOW PRESSURE AND A TRAILING COLD FRONT WILL
MOVE VERY SLOWLY TOWARD THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE
WEEK...BEFORE SHIFTING INTO THE WESTERN ATLANTIC THURSDAY. HIGH PRESSURE
WILL THEN BUILD IN FROM THE NORTH FRIDAY THROUGH MONDAY. LOW PRESSURE
COULD FORM FAR OFFSHORE IN THE WESTERN ATLANTIC IN ASSOCIATION WITH
A CLOSED LOW ALOFT SATURDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
EARLY THIS MORNING...LINGERING SHOWERS AND THUNDERSTORMS HAVE
LARGELY DIMINISHED WITH JUST A FEW SHOWERS WORKING THEIR WAY INTO
PARTS OF TATTNALL AND LONG COUNTIES. WILL KEEP ISOLATED COVERAGE
GOING FOR THE NEXT FEW HOURS. STRATUS IS TRYING TO DEVELOP ACROSS
PORTIONS OF THE REGION AND MAY EXPAND THROUGH DAYBREAK. IT APPEARS
WE WILL MAINTAIN ENOUGH LOW LEVEL FLOW TO PREVENT FOG FORMATION SO
I HAVE NOT ADDED FOG WORDING TO THE FORECAST. WITH THE CONTINUED
FLOW...TEMPS WILL ONLY FALL INTO THE UPPER 60S IN MOST AREAS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
SOUTHWEST FLOW ALOFT WILL PERSIST THROUGH WEDNESDAY ACROSS THE AREA
IN ADVANCE OF AN UPPER LEVEL TROUGH. THE UPPER LEVEL TROUGH WILL
SWING THROUGH THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY AND ALLOW
FOR A SURFACE COLD FRONT TO MOVE THROUGH THE AREA.

DEEP MOISTURE WITH PRECIPITABLE WATER VALUES NEAR 1.5 INCHES
TUESDAY THROUGH WEDNESDAY...COMBINED WITH SOME DAYTIME HEATING AND
UPPER LEVEL DISTURBANCES EMBEDDED IN THE SOUTHWEST FLOW ALOFT WILL
AID IN THE DEVELOPMENT OF WIDELY SCATTERED TO SCATTERED MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. AT THE PRESENT TIME
IS APPEARS THAT THE BEST COVERAGE WILL BE ON WEDNESDAY AND
MAINTAINED HIGHER RAIN CHANCES THEN. CANNOT RULE OUT A FEW STRONG TO
SEVERE THUNDERSTORMS EACH DAY...BUT FEEL THAT WITH SLIGHTLY COOLER
TEMPERATURES ALOFT..THAT THERE IS A SLIGHTLY BETTER CHANCE FOR
SEVERE THUNDERSTORMS ON WEDNESDAY. HIGH TEMPERATURES WILL BE
FAIRLY CLOSE TO SEASONAL NORMS...MAINLY IN THE MID 80S AWAY FROM THE
COAST.

IT LOOKS LIKE THE MID LEVEL TROUGH AND SURFACE COLD FRONT MOVE EAST
OF THE AREA BY LATE THURSDAY...ALLOWING FOR SOME DRIER AIR TO WORK
IN FROM THE NORTHWEST. CANNOT TOTALLY RULE OUT PRECIPITATION CHANCES
THURSDAY...BUT WITH THE UPPER LEVEL TROUGH EAST OF THE
AREA...LOWERED THE THREAT FOR RAIN INTO THE SLIGHT CHANCE CATEGORY
FOR MOST LOCALS...EXCEPT THE SOUTH WHERE CHANCE POPS WERE
MAINTAINED. MORE SUNSHINE ON THURSDAY BEHIND THE FRONT WILL MOSTLY
OFFSET THE COOLING BEHIND THE FRONT AND EXPECT HIGH TEMPERATURES TO
MAINLY BE IN THE LOWER TO MID 80S AWAY FROM THE COAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR THE END OF THIS WEEK INTO THE EARLY PART OF NEXT
WEEK IS STILL SOMEWHAT UP IN THE AIR...BUT CONSENSUS SUGGESTS THAT
WE MIGHT GET BY WITH A FEW DAYS WITHOUT RAINFALL.

THE TROUGH IN THE ATLANTIC WILL CLOSE OFF DURING FRIDAY...CAUSING A
SURFACE LOW TO FORM SOMEWHERE OUT NEAR 30 NORTH AND 70 WEST. THAT
LOW LOOKS TO MEANDER WELL OFFSHORE DURING AT LEAST THE
WEEKEND...BEFORE TURNING NORTH AT SOME POINT EARLY NEXT WEEK AS THE
CLOSED LOW OPENS AND LIFTS OUT. AT THE SAME TIME...STRONG HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH. LARGE SCALE
SUBSIDENCE LOOKS TO TAKE HOLD...WHILE THE BEST LOW LEVEL CONVERGENCE
REMAINS SOUTH OF THE AREA. THIS SHOULD KEEP THE AREA GENERALLY FREE
OF RAINFALL...ALTHOUGH SOME COASTAL SHOWERS COULD CERTAINLY OCCUR.

ADDITIONALLY....A TIGHTER PRESSURE GRADIENT WILL FORM AND BREEZY
CONDITIONS WILL OCCUR EACH DAY FRIDAY THROUGH SUNDAY...ESPECIALLY
OVER OUR COASTAL COUNTIES. THE DRIER AIR MASS WILL ALLOW FOR NIGHT
TIME LOWS TO FALL INTO THE UPPER 50S ACROSS INTERIORS SECTIONS EACH
NIGHT...WHILE AMPLE INSOLATION WILL BOOST DAYTIME HIGHS INTO THE
LOWER 80S EACH AFTERNOON AWAY FROM THE COAST.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THE PRIMARY NEAR TERM CONCERN IS THE POTENTIAL FOR STRATUS AND/OR
FOG AT KCHS AND KSAV. IT LOOKS LIKE THERE WILL BE ENOUGH LOW LEVEL
FLOW TO PREVENT FOG FORMATION THROUGH SUNRISE SO I HAVE NOT
INTRODUCED ANY REDUCED VISIBILITIES. STRATUS APPEARS MORE LIKELY
AND IS ALREADY DEVELOPING ACROSS AN AREA FROM BEAUFORT TO
WALTERBORO AND INTO THE MIDLANDS. THE CURRENT STRATUS LINES UP
WELL WITH AN AREA OF CLEAR SKIES NORTH OF THE DEBRIS CLOUDS FROM
DIMINISHING SHOWERS OVER SE GA. I HAVE ADDED IN A TEMPO GROUP FOR
MVFR CIGS AT KCHS...AND KEPT KSAV VFR.

THIS AFTERNOON...FORECAST CONCERNS SHIFT TO THE POTENTIAL FOR
THUNDERSTORM DEVELOPMENT. CURRENT THINKING IS THAT DEVELOPMENT
WILL BE DELAYED INTO THE MID/LATE AFTERNOON HOURS WITH THE BEST
COVERAGE OCCURRING IN AND AROUND THE KSAV AREA. THEREFORE...I HAVE
ADDED A PROB30 GROUP TO KSAV AND LEFT IT OUT AT KCHS FOR NOW.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO LOW LEVEL
MOISTURE AND SCATTERED SHRA/TSRA. VFR CONDITIONS WILL RETURN BY
FRIDAY.

&&

.MARINE...
WEAK SURFACE LOW PRESSURE TO THE WEST WILL DRAW SLIGHTLY CLOSER
AND S WINDS WILL VEER TOWARD THE SW. WINDS ARE EXPECTED TO REMAIN
AT OR BELOW 15 KTS THROUGH TONIGHT. SEAS OF 2-3 FEET WITHIN
NEARSHORE WATERS AND AS HIGH AS 4 FT BEYOND 20 NM SHOULD PREVAIL.

ALTHOUGH PERIODIC SHOWERS AND T-STORMS WILL IMPACT THE COASTAL
WATERS TUESDAY THROUGH THURSDAY...THE GENERAL WIND AND WAVE
CONDITIONS WILL REMAIN WELL BELOW ANY SCA LEVELS. THAT COULD CHANGE
LATE IN THE WEEK...WITH THE POTENTIAL FOR A DECENT PINCHING OF THE
PRESSURE GRADIENT TO OCCUR. STRONG HIGH PRESSURE WILL BUILD OUT OF
THE NE STATES THURSDAY NIGHT INTO THE WEEKEND...WHILE LOW PRESSURE
FORMS FAR OFF THE SE COAST. THE RESULTING PRESSURE DIFFERENCE
BETWEEN THESE TWO FEATURES WILL BE LARGE ENOUGH TO CAUSE WINDS AND
SEAS TO LIKELY REACH HIGH ENOUGH WHERE SCA/S WILL BE REQUIRED LATER
THIS WEEK.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...MTE
LONG TERM...
AVIATION...BSH
MARINE...SPR/MTE/JAQ

000
FXUS62 KFFC 150559 AAC
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
159 AM EDT TUE MAY 15 2012

.PREV DISCUSSION...

UPDATE...
/ISSUED 1138 PM EDT MON MAY 14 2012/
QUICK UPDATE TO TWEAK POPS AND WX BASED ON RECENT TRENDS. ALSO
ADDED PATCHY FOG TO MOST AREAS AFTER 09Z TONIGHT. IF STRATUS CAN
DEVELOP OVER THE AREA...WILL LIMIT FOG POTENTIAL BUT SO
FAR...APPEARS MOST AREAS HAVE ONLY HIGH CLOUDS. RECENT MAV AND MET
GUIDANCE ALSO INDICATING SOME POTENTIAL FOR LIGHT FOG AS WELL.
REST OF FCST LOOKS GOOD.

SNELSON

SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
/ISSUED 341 PM EDT MON MAY 14 2012/
A LARGE TROUGH REMAINS IN PLACE ACROSS THE SOUTHERN TWO THIRDS OF
THE UNITED STATES WHILE WEAK SHORT WAVES THAT TRANSVERSE THROUGH
THE FLOW WILL CONTINUE TO DOMINATE OUR WEATHER IN THE SHORT TERM.
OVERNIGHT TONIGHT WE SHOULD CONTINUE TO HAVE SOME CLOUDS ACROSS
THE AREA. CHANCES OF PRECIP WILL BE LOW IF NOT NIL OVERNIGHT.
EXPECT A STRATUS DECK TO MAKE ITS WAY INTO THE AREA TOMORROW NEAR
DAY BREAK. AMPLE LOW LEVEL MOISTURE EXISTS ACROSS THE PEACH STATE
FOR CHANCES OF THUNDERSTORMS TOMORROW AS A SHORT WAVE MOVES
THROUGH THE FLOW. CAPE VALUES ARE PROGGED TO BE FROM 1500 TO 2000
J/KG. DAYTIME HEATING ALONG WITH THE CAPE AND UPPER LEVEL
SHORTWAVE SHOULD LEAD TO SOME THUNDERSTORMS TOMORROW AFTERNOON.
THESE THUNDERSTORMS WILL BE MUCH LIKE THE TYPICAL SUMMERTIME
VARIETY WE EXPERIENCE DUE TO WEAK SHEAR AND FLOW ALOFT.

TUESDAY NIGHT...EXPECT CLOUDS TO START TO CLEAR OUT OF THE AREA
STARTING FROM THE NORTHWEST...AS THE UPPER LEVEL TROUGH STARTS TO
EJECT OUT TO THE EAST.

AS FOR TEMPERATURES...USED A BLEND OF THE MET AND MAV FOR THE HIGHS
AND LOWS.  DID NO OTHER TWEAKS TO THE TEMPERATURES.

GIBBS

LONG TERM /WEDNESDAY THROUGH MONDAY/...
/ISSUED 341 PM EDT MON MAY 14 2012/
HAVE MADE NO CHANGES TO THE EXTENDED. OVERALL PATTERN REMAINS THE
SAME. A FRONTAL BOUNDARY LOOKS LIKE IT MAY APPROACH THE NORTHERN
BORDER OF GEORGIA BY THE END OF THE PERIOD...BUT WILL ADD NO POPS
AT THIS TIME. THE PREVIOUS DISCUSSION IS INCLUDED BELOW.

41

PREVIOUS LONG TERM /ISSUED 420 AM EDT MON MAY 14 2012/
THREAT FOR SHOWERS AND THUNDERSTORMS CONTINUING INTO WEDNESDAY
WITH UPPER TROF STILL OVER THE AREA AND REMNANTS OF WEAK SURFACE
BOUNDARY SOMEWHERE ACROSS CENTRAL GEORGIA. EXTENDED PROGS SIMILAR
WITH AXIS OF UPPER TROF FINALLY SHIFTING EAST OF THE COUNTY
WARNING AREA THURSDAY AS A WEAK UPPER RIDGE BUILDS IN FROM THE
WEST. RIDGE LOOKS TO DOMINATE OUR AREA INTO THE WEEKEND...BUT
LATEST MODEL RUNS CONTINUE TO SHOW A COASTAL LOW DEVELOPING OFF
THE MID ATLANTIC/SOUTHEAST U.S. COAST SAT/SUN TIME FRAME WITH SOME
DEEPER MOISTURE POSSIBLY GETTING INTO PORTIONS OF EAST GEORGIA.
HAVE KEEP THE FORECAST DRY FOR NOW WITH SEVERAL MODEL RUNS YET TO
GO...AND UNCERTAINTY TO IF AND WHERE LOW WILL FORM. TEMPS
GENERALLY RUNNING NEAR NORMAL LEVELS THROUGH THE PERIOD.

49

&&

.AVIATION...
06Z UPDATE...
PRECIP HAS ENDED ACROSS MOST OF THE AREA AND EXPECT THIS LULL TO
CONTINUE THROUGH LATE THIS MORNING. MAIN CONCERN THIS MORNING WILL
BE LOW CLOUDS AND FOG. PLENTY OF LOW LEVEL MOISTURE TO SEE IFR TO
MVFR CONDITIONS THIS MORNING BUT CHALLENGE IS TIMING AND JUST HOW
LOW THESE CONDITIONS WILL BECOME. CHANCE OF THUNDERSTORMS AT THE
TAF SITES THIS AFTERNOON...ENOUGH TO WARRANT THE CONTINUATION OF
THE PROB 30 AT ALL SITES BUT CSG. WINDS WILL REMAIN WEST TO
NORTHWEST TODAY.

//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ON WIND. HIGH CONFIDENCE ON CIG HEIGHT AND VSBYS
EXCEPT LOW CONFIDENCE FROM 10Z TO 15Z. LOW CONFIDENCE ON THUNDER
OCCURRING AT THE AIRPORT THIS AFTERNOON.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          82  60  83  58 /  30  30  20  20
ATLANTA         80  62  81  61 /  30  30  20  10
BLAIRSVILLE     75  55  78  54 /  30  30  20  10
CARTERSVILLE    80  58  82  55 /  20  30  20  10
COLUMBUS        84  63  83  61 /  20  20  20  10
GAINESVILLE     79  60  82  59 /  30  30  20  10
MACON           85  61  84  60 /  30  30  20  10
ROME            81  58  82  55 /  20  30  10  10
PEACHTREE CITY  81  58  81  56 /  30  30  20  10
VIDALIA         86  66  85  64 /  30  40  30  20

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS62 KCAE 150526
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
126 AM EDT TUE MAY 15 2012

.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL REMAIN IN THE AREA THROUGH
WEDNESDAY.

&&

.NEAR TERM /THROUGH TODAY/...
REST OF TONIGHT...CONVERGENCE ASSOCIATED WITH A BOUNDARY WAS
SUPPORTING SHOWERS AND THUNDERSTORMS IN THE NORTH PART OF THE
FORECAST AREA EARLY THIS MORNING. SOME TRAINING WAS OCCURRING AND
HEAVY RAINFALL MAY OCCUR. ELSEWHERE...CONVERGENCE WAS WEAK AND
RADAR TRENDS SUPPORTED LOW POPS. EXPECT LOWS MAINLY IN THE MID
60S.

TODAY...CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH AND ANOTHER
MID-LEVEL SHORTWAVE TROUGH PLUS HEATING SUPPORTS SHOWERS AND
THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. USED THE HIGHER
GUIDANCE POPS BECAUSE OF THIS SUPPORT. LOW-LEVEL MOISTURE ASSOCIATED
WITH CONVERGENCE INTO THE SURFACE TROUGH WILL REMAIN HIGH TODAY.
UPPER-LEVEL MOISTURE WILL BE A LITTLE LESS COMPARED TO THE PAST FEW
DAYS. EXPECT THE DIMINISHED MOISTURE WILL LEAD TO MORE HEATING AND
INSTABILITY. THE MODELS INDICATE MODERATE TO STRONG INSTABILITY THIS
AFTERNOON SUPPORTING POSSIBLE DAMAGING WIND AND HAIL WITH A FEW OF
THE THUNDERSTORMS. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FORECAST.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.

AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. TEMPERATURES SHOULD BE WARMER WEDNESDAY
WITH SOME BREAKS IN THE OVERCAST MID MORNING THROUGH EARLY
AFTERNOON.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
HIGH LOW-LEVEL MOISTURE WILL BRING WIDESPREAD IFR CEILINGS EARLY
THIS MORNING. HEATING AND MIXING WILL RESULT IN SOME IMPROVEMENT
LATER THIS MORNING. USED THE GFS LAMP FOR THE TIMING. HOWEVER...
CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH AND ANOTHER
MID-LEVEL SHORTWAVE TROUGH PLUS HEATING SUPPORTS THUNDERSTORMS...
ESPECIALLY DURING THE AFTERNOON. DID NOT INCLUDE THUNDERSTORMS IN
THE TERMINAL FORECAST BECAUSE OF TIMING UNCERTAINTY. STRONG
HEATING WITH COLD AIR ALOFT ASSOCIATED WITH THE UPPER TROUGH WILL
RESULT IN MODERATE TO STRONG INSTABILITY. ANY THUNDERSTORMS MAY
CONTAIN STRONG WIND AND HAIL.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
ASSOCIATED WITH THE SLOW MOVING FRONT MAY OCCUR THROUGH WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KFFC 150338 AAB
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1138 PM EDT MON MAY 14 2012


.UPDATE...
QUICK UPDATE TO TWEAK POPS AND WX BASED ON RECENT TRENDS. ALSO
ADDED PATCHY FOG TO MOST AREAS AFTER 09Z TONIGHT. IF STRATUS CAN
DEVELOP OVER THE AREA...WILL LIMIT FOG POTENTIAL BUT SO
FAR...APPEARS MOST AREAS HAVE ONLY HIGH CLOUDS. RECENT MAV AND MET
GUIDANCE ALSO INDICATING SOME POTENTIAL FOR LIGHT FOG AS WELL.
REST OF FCST LOOKS GOOD.

SNELSON

&&

.PREV DISCUSSION... /ISSUED 814 PM EDT MON MAY 14 2012/

SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
A LARGE TROUGH REMAINS IN PLACE ACROSS THE SOUTHERN TWO THIRDS OF
THE UNITED STATES WHILE WEAK SHORT WAVES THAT TRANSVERSE THROUGH
THE FLOW WILL CONTINUE TO DOMINATE OUR WEATHER IN THE SHORT TERM.
OVERNIGHT TONIGHT WE SHOULD CONTINUE TO HAVE SOME CLOUDS ACROSS
THE AREA. CHANCES OF PRECIP WILL BE LOW IF NOT NIL OVERNIGHT.
EXPECT A STRATUS DECK TO MAKE ITS WAY INTO THE AREA TOMORROW NEAR
DAY BREAK. AMPLE LOW LEVEL MOISTURE EXISTS ACROSS THE PEACH STATE
FOR CHANCES OF THUNDERSTORMS TOMORROW AS A SHORT WAVE MOVES
THROUGH THE FLOW. CAPE VALUES ARE PROGGED TO BE FROM 1500 TO 2000
J/KG. DAYTIME HEATING ALONG WITH THE CAPE AND UPPER LEVEL
SHORTWAVE SHOULD LEAD TO SOME THUNDERSTORMS TOMORROW AFTERNOON.
THESE THUNDERSTORMS WILL BE MUCH LIKE THE TYPICAL SUMMERTIME
VARIETY WE EXPERIENCE DUE TO WEAK SHEAR AND FLOW ALOFT.

TUESDAY NIGHT...EXPECT CLOUDS TO START TO CLEAR OUT OF THE AREA
STARTING FROM THE NORTHWEST...AS THE UPPER LEVEL TROUGH STARTS TO
EJECT OUT TO THE EAST.

AS FOR TEMPERATURES...USED A BLEND OF THE MET AND MAV FOR THE HIGHS
AND LOWS.  DID NO OTHER TWEAKS TO THE TEMPERATURES.

GIBBS

LONG TERM /WEDNESDAY THROUGH MONDAY/...
HAVE MADE NO CHANGES TO THE EXTENDED. OVERALL PATTERN REMAINS THE
SAME. A FRONTAL BOUNDARY LOOKS LIKE IT MAY APPROACH THE NORTHERN
BORDER OF GEORGIA BY THE END OF THE PERIOD...BUT WILL ADD NO POPS
AT THIS TIME. THE PREVIOUS DISCUSSION IS INCLUDED BELOW.

41

PREVIOUS LONG TERM /ISSUED 420 AM EDT MON MAY 14 2012/
THREAT FOR SHOWERS AND THUNDERSTORMS CONTINUING INTO WEDNESDAY
WITH UPPER TROF STILL OVER THE AREA AND REMNANTS OF WEAK SURFACE
BOUNDARY SOMEWHERE ACROSS CENTRAL GEORGIA. EXTENDED PROGS SIMILAR
WITH AXIS OF UPPER TROF FINALLY SHIFTING EAST OF THE COUNTY
WARNING AREA THURSDAY AS A WEAK UPPER RIDGE BUILDS IN FROM THE
WEST. RIDGE LOOKS TO DOMINATE OUR AREA INTO THE WEEKEND...BUT
LATEST MODEL RUNS CONTINUE TO SHOW A COASTAL LOW DEVELOPING OFF
THE MID ATLANTIC/SOUTHEAST U.S. COAST SAT/SUN TIME FRAME WITH SOME
DEEPER MOISTURE POSSIBLY GETTING INTO PORTIONS OF EAST GEORGIA.
HAVE KEEP THE FORECAST DRY FOR NOW WITH SEVERAL MODEL RUNS YET TO
GO...AND UNCERTAINTY TO IF AND WHERE LOW WILL FORM. TEMPS
GENERALLY RUNNING NEAR NORMAL LEVELS THROUGH THE PERIOD.

49

AVIATION...
00Z UPDATE...
LOW PRESSURE CENTER MOVING NORTHEAST UP THE EASTERN SEABOARD
PULLING MOISTURE WITH IT. ISOLATED SHOWERS AND THUNDERSTORMS
SLOWLY DISSIPATING AND MOVING EAST OUT OF THE AREA. CEILINGS ARE
SCT TO BKN IN THE VFR RANGE NOW BUT EXPECTING SOME MVFR CEILINGS
TO MOVE IN BY 10-12Z. THESE LOWER CEILINGS SHOULD LIFT BACK INTO
THE VFR RANGE BY 14-16Z. VSBYS SHOULD STAY VFR THROUGH THE PERIOD.
WINDS WILL STAY OUT OF THE W-NW IN THE 5-10 KT RANGE.

//ATL CONFIDENCE...00Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS.

SMITH

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          59  82  60  83 /  40  30  30  20
ATLANTA         61  80  62  81 /  20  30  30  20
BLAIRSVILLE     54  75  55  78 /  50  30  30  20
CARTERSVILLE    58  80  58  82 /  20  20  30  20
COLUMBUS        63  84  63  83 /  10  20  20  20
GAINESVILLE     59  79  60  82 /  40  30  30  20
MACON           61  85  61  84 /  20  30  30  20
ROME            58  81  58  82 /  30  20  30  10
PEACHTREE CITY  58  81  58  81 /  10  30  30  20
VIDALIA         66  86  66  85 /  30  30  40  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...NELSON
LONG TERM....NELSON
AVIATION...SMITH

000
FXUS62 KCHS 150232
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1032 PM EDT MON MAY 14 2012

.SYNOPSIS...
A BROAD AND WEAK AREA OF LOW PRESSURE AND A TRAILING COLD FRONT WILL
MOVE VERY SLOWLY TOWARD THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE
WEEK...BEFORE SHIFTING INTO THE WESTERN ATLANTIC THURSDAY. HIGH PRESSURE
WILL THEN BUILD IN FROM THE NORTH FRIDAY THROUGH MONDAY. LOW PRESSURE
COULD FORM FAR OFFSHORE IN THE WESTERN ATLANTIC IN ASSOCIATION WITH
A CLOSED LOW ALOFT SATURDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
BROAD UPPER LEVEL TROUGHING WILL EXTEND FROM THE OHIO VALLEY
THROUGH THE SOUTHERN PLAINS TONIGHT. MEANWHILE...SEVERAL SHORT
WAVE DISTURBANCES EMBEDDED WITHIN THE CYCLONIC FLOW ALOFT WILL
CONTINUE TO TRACK ACROSS THE REGION. AT THE SURFACE...THE AREA
WILL REMAIN LOCATED BETWEEN HIGH PRESSURE EAST OF NOVA SCOTIA AND
WEAK/ELONGATED LOW PRESSURE AND ITS ASSOCIATED COLD FRONT
EXTENDING FROM THE SOUTHERN APPALACHIANS...ACROSS THE FLORIDA
PANHANDLE AND INTO THE NORTHEAST GULF OF MEXICO.

DIURNAL STABILIZATION HAS TRANSLATED TO A STEADY DECREASE IN
THUNDERSTORM COVERAGE/INTENSITY...AND THIS TREND WILL GENERALLY
CONTINUE INTO THE EARLY OVERNIGHT HOURS. DESPITE PLENTY OF LOW
LEVEL MOISTURE...WOULD NOT BE SURPRISED IF PRECIPITATION
COMPLETELY DISSIPATES OVER LAND BY LATE TONIGHT...BUT KEPT MENTION
OF ISOLATED SHOWERS/THUNDERSTORMS IN THE FORECAST FOR MOST PLACES.

THERE COULD ACTUALLY BE SOME BREAKS IN THE CLOUD COVER
TONIGHT...BUT THERE IS THE POTENTIAL FOR FOG/STATUS TO DEVELOP
TOWARD DAYBREAK. THIS IS DUE TO RELATIVELY LIGHT SOUTHERLY
WINDS KEEPING MOIST BOUNDARY LAYER CONDITIONS IN PLACE...WITH THE
FOG/STATUS MORE PROBABLE WHERE THE HEAVIEST RAINFALL OCCURRED
EARLIER.

LOWS TONIGHT ARE FORECAST TO BE IN THE MID 60S ACROSS MOST INLAND
AREAS...WITH UPPER 60S CLOSER TO THE COAST.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
SOUTHWEST FLOW ALOFT WILL PERSIST THROUGH WEDNESDAY ACROSS THE AREA
IN ADVANCE OF AN UPPER LEVEL TROUGH. THE UPPER LEVEL TROUGH WILL
SWING THROUGH THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY AND ALLOW
FOR A SURFACE COLD FRONT TO MOVE THROUGH THE AREA.

DEEP MOISTURE WITH PRECIPITABLE WATER VALUES NEAR 1.5 INCHES
TUESDAY THROUGH WEDNESDAY...COMBINED WITH SOME DAYTIME HEATING AND
UPPER LEVEL DISTURBANCES EMBEDDED IN THE SOUTHWEST FLOW ALOFT WILL
AID IN THE DEVELOPMENT OF WIDELY SCATTERED TO SCATTERED MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. AT THE PRESENT TIME
IS APPEARS THAT THE BEST COVERAGE WILL BE ON WEDNESDAY AND
MAINTAINED HIGHER RAIN CHANCES THEN. CANNOT RULE OUT A FEW STRONG TO
SEVERE THUNDERSTORMS EACH DAY...BUT FEEL THAT WITH SLIGHTLY COOLER
TEMPERATURES ALOFT..THAT THERE IS A SLIGHTLY BETTER CHANCE FOR
SEVERE THUNDERSTORMS ON WEDNESDAY. HIGH TEMPERATURES WILL BE
FAIRLY CLOSE TO SEASONAL NORMS...MAINLY IN THE MID 80S AWAY FROM THE
COAST.

IT LOOKS LIKE THE MID LEVEL TROUGH AND SURFACE COLD FRONT MOVE EAST
OF THE AREA BY LATE THURSDAY...ALLOWING FOR SOME DRIER AIR TO WORK
IN FROM THE NORTHWEST. CANNOT TOTALLY RULE OUT PRECIPITATION CHANCES
THURSDAY...BUT WITH THE UPPER LEVEL TROUGH EAST OF THE
AREA...LOWERED THE THREAT FOR RAIN INTO THE SLIGHT CHANCE CATEGORY
FOR MOST LOCALS...EXCEPT THE SOUTH WHERE CHANCE POPS WERE
MAINTAINED. MORE SUNSHINE ON THURSDAY BEHIND THE FRONT WILL MOSTLY
OFFSET THE COOLING BEHIND THE FRONT AND EXPECT HIGH TEMPERATURES TO
MAINLY BE IN THE LOWER TO MID 80S AWAY FROM THE COAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR THE END OF THIS WEEK INTO THE EARLY PART OF NEXT
WEEK IS STILL SOMEWHAT UP IN THE AIR...BUT CONSENSUS SUGGESTS THAT
WE MIGHT GET BY WITH A FEW DAYS WITHOUT RAINFALL.

THE TROUGH IN THE ATLANTIC WILL CLOSE OFF DURING FRIDAY...CAUSING A
SURFACE LOW TO FORM SOMEWHERE OUT NEAR 30 NORTH AND 70 WEST. THAT
LOW LOOKS TO MEANDER WELL OFFSHORE DURING AT LEAST THE
WEEKEND...BEFORE TURNING NORTH AT SOME POINT EARLY NEXT WEEK AS THE
CLOSED LOW OPENS AND LIFTS OUT. AT THE SAME TIME...STRONG HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH. LARGE SCALE
SUBSIDENCE LOOKS TO TAKE HOLD...WHILE THE BEST LOW LEVEL CONVERGENCE
REMAINS SOUTH OF THE AREA. THIS SHOULD KEEP THE AREA GENERALLY FREE
OF RAINFALL...ALTHOUGH SOME COASTAL SHOWERS COULD CERTAINLY OCCUR.

ADDITIONALLY....A TIGHTER PRESSURE GRADIENT WILL FORM AND BREEZY
CONDITIONS WILL OCCUR EACH DAY FRIDAY THROUGH SUNDAY...ESPECIALLY
OVER OUR COASTAL COUNTIES. THE DRIER AIR MASS WILL ALLOW FOR NIGHT
TIME LOWS TO FALL INTO THE UPPER 50S ACROSS INTERIORS SECTIONS EACH
NIGHT...WHILE AMPLE INSOLATION WILL BOOST DAYTIME HIGHS INTO THE
LOWER 80S EACH AFTERNOON AWAY FROM THE COAST.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
FOG AND/OR STRATUS COULD DEVELOP IN THE 08-14Z TIME FRAME AT
EITHER TERMINAL DUE TO MOIST LOW LEVEL CONDITIONS AND RELATIVELY
LIGHT SOUTHERLY WINDS. WHILE THE POTENTIAL FOR FOG/STATUS APPEARS
GREATEST AT KSAV WHERE MORE RAINFALL OCCURRED EARLIER...WILL LEAVE
CONDITIONS VFR AT THIS TIME GIVEN OVERALL LOW CONFIDENCE IN SUB-
VFR CONDITIONS DEVELOPING.

SCATTERED SHOWERS AND THUNDERSTORMS SHOULD REDEVELOP ON
TUESDAY...ESPECIALLY IN THE AFTERNOON...BUT PROB30 IS NOT YET
JUSTIFIED GIVEN UNCERTAINTY IN THE COVERAGE/TIMING OF CONVECTION.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO LOW LEVEL
MOISTURE AND SCATTERED SHRA/TSRA. VFR CONDITIONS WILL RETURN BY
FRIDAY.

&&

.MARINE...
WEAK SURFACE LOW PRESSURE TO THE WEST WILL DRAW SLIGHTLY CLOSER
AND S WINDS WILL VEER TOWARD THE SW. WINDS ARE EXPECTED TO REMAIN
AT OR BELOW 15 KTS THROUGH TONIGHT. SEAS OF 2-3 FEET WITHIN
NEARSHORE WATERS AND AS HIGH AS 4 FT BEYOND 20 NM SHOULD PREVAIL.

ALTHOUGH PERIODIC SHOWERS AND T-STORMS WILL IMPACT THE COASTAL
WATERS TUESDAY THROUGH THURSDAY...THE GENERAL WIND AND WAVE
CONDITIONS WILL REMAIN WELL BELOW ANY SCA LEVELS. THAT COULD CHANGE
LATE IN THE WEEK...WITH THE POTENTIAL FOR A DECENT PINCHING OF THE
PRESSURE GRADIENT TO OCCUR. STRONG HIGH PRESSURE WILL BUILD OUT OF
THE NE STATES THURSDAY NIGHT INTO THE WEEKEND...WHILE LOW PRESSURE
FORMS FAR OFF THE SE COAST. THE RESULTING PRESSURE DIFFERENCE
BETWEEN THESE TWO FEATURES WILL BE LARGE ENOUGH TO CAUSE WINDS AND
SEAS TO LIKELY REACH HIGH ENOUGH WHERE SCA/S WILL BE REQUIRED LATER
THIS WEEK.

&&

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

&&

$$

NEAR TERM...JAQ
SHORT TERM...MTE
LONG TERM...
AVIATION...JAQ
MARINE...JAQ/MTE

000
FXUS62 KCAE 150216
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1016 PM EDT MON MAY 14 2012

.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL REMAIN IN THE AREA THROUGH
WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH WILL CONTINUE TO
SUPPORT SHOWERS AND THUNDERSTORMS OVERNIGHT. HOWEVER...RADAR HAS
SHOWN A DIMINISHING TREND BECAUSE OF THE LOSS OF HEATING. EXPECT
LITTLE COVERAGE OVERNIGHT AND CHANCE POPS STILL APPEAR ON TRACK.
TEMPERATURES TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS AND
CLOUDS. EXPECT LOWS MAINLY IN THE MID 60S.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.

AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE
LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY
NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE
WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS
AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE
WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID
MORNING THROUGH EARLY AFTERNOON.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING PLENTY
OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW. THE WIND SHOULD
FAVOR MORE IFR STRATUS CEILING THAN IFR FOG. WILL GO MAINLY MVFR
VSBYS WITH FOG MOST LOCATIONS TUESDAY NEAR DAYBREAK BUT WILL HAVE
LOWER IFR VSBYS AT AGS AND OGB. AFTER 14Z TUESDAY MORNING...CONDITIONS
SHOULD HAVE IMPROVED TO VFR AGAIN BUT SHOWERS AND THUNDERSTORMS
SHOULD DEVELOP AGAIN BY TUESDAY AFTERNOON. DUE TO UNCERTAINTY AS
TO TIMING AND AERIAL COVERAGE...DECIDED TO LEAVE MENTION OF
SHOWERS AND THUNDERSTORMS OUT OF TAF SITES.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
ASSOCIATED WITH THE SLOW MOVING FRONT MAY OCCUR THROUGH WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KCHS 150023
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
823 PM EDT MON MAY 14 2012

.SYNOPSIS...
A BROAD AND WEAK AREA OF LOW PRESSURE AND A TRAILING COLD FRONT WILL
MOVE VERY SLOWLY TOWARD THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE
WEEK...BEFORE SHIFTING INTO THE WESTERN ATLANTIC THURSDAY. HIGH PRESSURE
WILL THEN BUILD IN FROM THE NORTH FRIDAY THROUGH MONDAY. LOW PRESSURE
COULD FORM FAR OFFSHORE IN THE WESTERN ATLANTIC IN ASSOCIATION WITH
A CLOSED LOW ALOFT SATURDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
BROAD UPPER LEVEL TROUGHING WILL EXTEND FROM THE OHIO VALLEY
THROUGH THE SOUTHERN PLAINS TONIGHT. MEANWHILE...SEVERAL SHORT
WAVE DISTURBANCES EMBEDDED WITHIN THE CYCLONIC FLOW ALOFT WILL
CONTINUE TO TRACK ACROSS THE REGION. AT THE SURFACE...THE AREA
WILL REMAIN LOCATED BETWEEN HIGH PRESSURE EAST OF NOVA SCOTIA AND
WEAK/ELONGATED LOW PRESSURE AND ITS ASSOCIATED COLD FRONT
EXTENDING FROM THE SOUTHERN APPALACHIANS...ACROSS THE FLORIDA
PANHANDLE AND INTO THE NORTHEAST GULF OF MEXICO.

DIURNAL STABILIZATION HAS TRANSLATED TO A STEADY DECREASE IN
THUNDERSTORM COVERAGE/INTENSITY...AND THIS TREND WILL GENERALLY
CONTINUE THROUGH THE REMAINDER OF THE EVENING. DESPITE PLENTY OF
LOW LEVEL MOISTURE...WOULD NOT BE SURPRISED IF PRECIPITATION
COMPLETELY DISSIPATES OVER LAND AFTER MIDNIGHT...BUT HAVE HELD
ONTO A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS IN MOST PLACES FOR
NOW OVERNIGHT.

THERE COULD ACTUALLY BE SOME BREAKS IN THE CLOUD COVER
TONIGHT...BUT THERE IS THE POTENTIAL FOR FOG/STATUS TO DEVELOP
TOWARD DAYBREAK. THIS IS DUE TO RELATIVELY LIGHT SOUTHERLY
WINDS KEEPING MOIST BOUNDARY LAYER CONDITIONS IN PLACE...WITH THE
FOG/STATUS MORE PROBABLE WHERE THE HEAVIEST RAINFALL OCCURRED
EARLIER.

LOWS TONIGHT ARE FORECAST TO BE IN THE MID 60S ACROSS MOST INLAND
AREAS...WITH UPPER 60S CLOSER TO THE COAST.


&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
SOUTHWEST FLOW ALOFT WILL PERSIST THROUGH WEDNESDAY ACROSS THE AREA
IN ADVANCE OF AN UPPER LEVEL TROUGH. THE UPPER LEVEL TROUGH WILL
SWING THROUGH THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY AND ALLOW
FOR A SURFACE COLD FRONT TO MOVE THROUGH THE AREA.

DEEP MOISTURE WITH PRECIPITABLE WATER VALUES NEAR 1.5 INCHES
TUESDAY THROUGH WEDNESDAY...COMBINED WITH SOME DAYTIME HEATING AND
UPPER LEVEL DISTURBANCES EMBEDDED IN THE SOUTHWEST FLOW ALOFT WILL
AID IN THE DEVELOPMENT OF WIDELY SCATTERED TO SCATTERED MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. AT THE PRESENT TIME
IS APPEARS THAT THE BEST COVERAGE WILL BE ON WEDNESDAY AND
MAINTAINED HIGHER RAIN CHANCES THEN. CANNOT RULE OUT A FEW STRONG TO
SEVERE THUNDERSTORMS EACH DAY...BUT FEEL THAT WITH SLIGHTLY COOLER
TEMPERATURES ALOFT..THAT THERE IS A SLIGHTLY BETTER CHANCE FOR
SEVERE THUNDERSTORMS ON WEDNESDAY. HIGH TEMPERATURES WILL BE
FAIRLY CLOSE TO SEASONAL NORMS...MAINLY IN THE MID 80S AWAY FROM THE
COAST.

IT LOOKS LIKE THE MID LEVEL TROUGH AND SURFACE COLD FRONT MOVE EAST
OF THE AREA BY LATE THURSDAY...ALLOWING FOR SOME DRIER AIR TO WORK
IN FROM THE NORTHWEST. CANNOT TOTALLY RULE OUT PRECIPITATION CHANCES
THURSDAY...BUT WITH THE UPPER LEVEL TROUGH EAST OF THE
AREA...LOWERED THE THREAT FOR RAIN INTO THE SLIGHT CHANCE CATEGORY
FOR MOST LOCALS...EXCEPT THE SOUTH WHERE CHANCE POPS WERE
MAINTAINED. MORE SUNSHINE ON THURSDAY BEHIND THE FRONT WILL MOSTLY
OFFSET THE COOLING BEHIND THE FRONT AND EXPECT HIGH TEMPERATURES TO
MAINLY BE IN THE LOWER TO MID 80S AWAY FROM THE COAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR THE END OF THIS WEEK INTO THE EARLY PART OF NEXT
WEEK IS STILL SOMEWHAT UP IN THE AIR...BUT CONSENSUS SUGGESTS THAT
WE MIGHT GET BY WITH A FEW DAYS WITHOUT RAINFALL.

THE TROUGH IN THE ATLANTIC WILL CLOSE OFF DURING FRIDAY...CAUSING A
SURFACE LOW TO FORM SOMEWHERE OUT NEAR 30 NORTH AND 70 WEST. THAT
LOW LOOKS TO MEANDER WELL OFFSHORE DURING AT LEAST THE
WEEKEND...BEFORE TURNING NORTH AT SOME POINT EARLY NEXT WEEK AS THE
CLOSED LOW OPENS AND LIFTS OUT. AT THE SAME TIME...STRONG HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH. LARGE SCALE
SUBSIDENCE LOOKS TO TAKE HOLD...WHILE THE BEST LOW LEVEL CONVERGENCE
REMAINS SOUTH OF THE AREA. THIS SHOULD KEEP THE AREA GENERALLY FREE
OF RAINFALL...ALTHOUGH SOME COASTAL SHOWERS COULD CERTAINLY OCCUR.

ADDITIONALLY....A TIGHTER PRESSURE GRADIENT WILL FORM AND BREEZY
CONDITIONS WILL OCCUR EACH DAY FRIDAY THROUGH SUNDAY...ESPECIALLY
OVER OUR COASTAL COUNTIES. THE DRIER AIR MASS WILL ALLOW FOR NIGHT
TIME LOWS TO FALL INTO THE UPPER 50S ACROSS INTERIORS SECTIONS EACH
NIGHT...WHILE AMPLE INSOLATION WILL BOOST DAYTIME HIGHS INTO THE
LOWER 80S EACH AFTERNOON AWAY FROM THE COAST.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
FOG AND/OR STRATUS COULD DEVELOP IN THE 08-14Z TIME FRAME AT
EITHER TERMINAL DUE TO MOIST LOW LEVEL CONDITIONS AND RELATIVELY
LIGHT SOUTHERLY WINDS. WHILE THE POTENTIAL FOR FOG/STATUS APPEARS
GREATEST AT KSAV WHERE MORE RAINFALL OCCURRED EARLIER...WILL LEAVE
CONDITIONS VFR AT THIS TIME GIVEN OVERALL LOW CONFIDENCE IN SUB-
VFR CONDITIONS DEVELOPING.

SCATTERED SHOWERS AND THUNDERSTORMS SHOULD REDEVELOP ON
TUESDAY...ESPECIALLY IN THE AFTERNOON...BUT PROB30 IS NOT YET
JUSTIFIED GIVEN UNCERTAINTY IN THE COVERAGE/TIMING OF CONVECTION.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO LOW LEVEL
MOISTURE AND SCATTERED SHRA/TSRA. VFR CONDITIONS WILL RETURN BY
FRIDAY.

&&

.MARINE...
WEAK SURFACE LOW PRESSURE TO THE WEST WILL DRAW SLIGHTLY CLOSER
AND S WINDS WILL VEER TOWARD THE SW. WINDS ARE EXPECTED TO REMAIN
AT OR BELOW 15 KTS THROUGH TONIGHT. SEAS OF 2-3 FEET WITHIN
NEARSHORE WATERS AND AS HIGH AS 4 FT BEYOND 20 NM SHOULD PREVAIL.

ALTHOUGH PERIODIC SHOWERS AND T-STORMS WILL IMPACT THE COASTAL
WATERS TUESDAY THROUGH THURSDAY...THE GENERAL WIND AND WAVE
CONDITIONS WILL REMAIN WELL BELOW ANY SCA LEVELS. THAT COULD CHANGE
LATE IN THE WEEK...WITH THE POTENTIAL FOR A DECENT PINCHING OF THE
PRESSURE GRADIENT TO OCCUR. STRONG HIGH PRESSURE WILL BUILD OUT OF
THE NE STATES THURSDAY NIGHT INTO THE WEEKEND...WHILE LOW PRESSURE
FORMS FAR OFF THE SE COAST. THE RESULTING PRESSURE DIFFERENCE
BETWEEN THESE TWO FEATURES WILL BE LARGE ENOUGH TO CAUSE WINDS AND
SEAS TO LIKELY REACH HIGH ENOUGH WHERE SCA/S WILL BE REQUIRED LATER
THIS WEEK.

&&

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

&&

$$

NEAR TERM...JAQ
SHORT TERM...MTE
LONG TERM...
AVIATION...JAQ
MARINE...JAQ/MTE

000
FXUS62 KFFC 150014
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
814 PM EDT MON MAY 14 2012



.PREV DISCUSSION... /ISSUED 341 PM EDT MON MAY 14 2012/

SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
A LARGE TROUGH REMAINS IN PLACE ACROSS THE SOUTHERN TWO THIRDS OF
THE UNITED STATES WHILE WEAK SHORT WAVES THAT TRANSVERSE THROUGH
THE FLOW WILL CONTINUE TO DOMINATE OUR WEATHER IN THE SHORT TERM.
OVERNIGHT TONIGHT WE SHOULD CONTINUE TO HAVE SOME CLOUDS ACROSS
THE AREA. CHANCES OF PRECIP WILL BE LOW IF NOT NIL OVERNIGHT.
EXPECT A STRATUS DECK TO MAKE ITS WAY INTO THE AREA TOMORROW NEAR
DAY BREAK. AMPLE LOW LEVEL MOISTURE EXISTS ACROSS THE PEACH STATE
FOR CHANCES OF THUNDERSTORMS TOMORROW AS A SHORT WAVE MOVES
THROUGH THE FLOW. CAPE VALUES ARE PROGGED TO BE FROM 1500 TO 2000
J/KG. DAYTIME HEATING ALONG WITH THE CAPE AND UPPER LEVEL
SHORTWAVE SHOULD LEAD TO SOME THUNDERSTORMS TOMORROW AFTERNOON.
THESE THUNDERSTORMS WILL BE MUCH LIKE THE TYPICAL SUMMERTIME
VARIETY WE EXPERIENCE DUE TO WEAK SHEAR AND FLOW ALOFT.

TUESDAY NIGHT...EXPECT CLOUDS TO START TO CLEAR OUT OF THE AREA
STARTING FROM THE NORTHWEST...AS THE UPPER LEVEL TROUGH STARTS TO
EJECT OUT TO THE EAST.

AS FOR TEMPERATURES...USED A BLEND OF THE MET AND MAV FOR THE HIGHS
AND LOWS.  DID NO OTHER TWEAKS TO THE TEMPERATURES.

GIBBS

LONG TERM /WEDNESDAY THROUGH MONDAY/...
HAVE MADE NO CHANGES TO THE EXTENDED. OVERALL PATTERN REMAINS THE
SAME. A FRONTAL BOUNDARY LOOKS LIKE IT MAY APPROACH THE NORTHERN
BORDER OF GEORGIA BY THE END OF THE PERIOD...BUT WILL ADD NO POPS
AT THIS TIME. THE PREVIOUS DISCUSSION IS INCLUDED BELOW.

41

PREVIOUS LONG TERM /ISSUED 420 AM EDT MON MAY 14 2012/
THREAT FOR SHOWERS AND THUNDERSTORMS CONTINUING INTO WEDNESDAY
WITH UPPER TROF STILL OVER THE AREA AND REMNANTS OF WEAK SURFACE
BOUNDARY SOMEWHERE ACROSS CENTRAL GEORGIA. EXTENDED PROGS SIMILAR
WITH AXIS OF UPPER TROF FINALLY SHIFTING EAST OF THE COUNTY
WARNING AREA THURSDAY AS A WEAK UPPER RIDGE BUILDS IN FROM THE
WEST. RIDGE LOOKS TO DOMINATE OUR AREA INTO THE WEEKEND...BUT
LATEST MODEL RUNS CONTINUE TO SHOW A COASTAL LOW DEVELOPING OFF
THE MID ATLANTIC/SOUTHEAST U.S. COAST SAT/SUN TIME FRAME WITH SOME
DEEPER MOISTURE POSSIBLY GETTING INTO PORTIONS OF EAST GEORGIA.
HAVE KEEP THE FORECAST DRY FOR NOW WITH SEVERAL MODEL RUNS YET TO
GO...AND UNCERTAINTY TO IF AND WHERE LOW WILL FORM. TEMPS
GENERALLY RUNNING NEAR NORMAL LEVELS THROUGH THE PERIOD.

49

&&

.AVIATION...
00Z UPDATE...
LOW PRESSURE CENTER MOVING NORTHEAST UP THE EASTERN SEABOARD
PULLING MOISTURE WITH IT. ISOLATED SHOWERS AND THUNDERSTORMS
SLOWLY DISSIPATING AND MOVING EAST OUT OF THE AREA. CEILINGS ARE
SCT TO BKN IN THE VFR RANGE NOW BUT EXPECTING SOME MVFR CEILINGS
TO MOVE IN BY 10-12Z. THESE LOWER CEILINGS SHOULD LIFT BACK INTO
THE VFR RANGE BY 14-16Z. VSBYS SHOULD STAY VFR THROUGH THE PERIOD.
WINDS WILL STAY OUT OF THE W-NW IN THE 5-10 KT RANGE.

//ATL CONFIDENCE...00Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS.

SMITH

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          59  82  60  83 /  40  30  30  20
ATLANTA         61  80  62  81 /  20  30  30  20
BLAIRSVILLE     54  75  55  78 /  50  30  30  20
CARTERSVILLE    58  80  58  82 /  20  20  30  20
COLUMBUS        63  84  63  83 /   5  20  20  20
GAINESVILLE     59  79  60  82 /  40  30  30  20
MACON           61  85  61  84 /  20  30  30  20
ROME            58  81  58  82 /  30  10  30  10
PEACHTREE CITY  58  81  58  81 /  10  30  30  20
VIDALIA         66  86  66  85 /  30  30  40  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...SMITH
LONG TERM....BAKER
AVIATION...SMITH

000
FXUS62 KCAE 150001
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
801 PM EDT MON MAY 14 2012

.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
TONIGHT THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO THE
REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT OVERNIGHT...
ESPECIALLY DURING THE EVENING HOURS. STORM GENERATION CONTINUES
ALONG A FRONTAL BOUNDARY IN THE NORTH AND OUTFLOW BOUNDARIES IN
THE SOUTH. DECIDED TO GO WITH 60-80 PERCENT POPS THOSE LOCATIONS
THE NEXT 2-3 HOURS AND WILL KEEP THE 40 PERCENT CHANCE ELSEWHERE.
HEAVIER SHOWERS AND THUNDERSTORMS MAY PRODUCE UP TO ONE INCH OF
RAIN. TEMPERATURES TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS
AND CLOUDS AND PRECIPITATION...GENERALLY IN THE MID 60S.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.

AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE
LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY
NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE
WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS
AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE
WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID
MORNING THROUGH EARLY AFTERNOON.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING PLENTY
OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW. SHOWERS AND
A FEW THUNDERSTORMS MAY DEVELOP NEXT 2-3 HOURS AT TAF SITES BUT WILL
LEAVE OUT MENTION OF CONVECTIVE ACTIVITY EXCEPT FOR OGB WHERE
SHOWERS OR THUNDERSTORMS ARE POSSIBLE UNTIL AROUND 01Z OR 02Z.
BUT WITH THE SUN SETTING...THE HEATING WILL BE GONE AND THE
CONVECTIVE ACTIVITY SHOULD BE OVER FOR THE NIGHT. WITH ANY SHOWER OR
THUNDERSTORM...THERE MAY BE BRIEF IFR-MVFR CONDITIONS THIS EVENING.
AFTER MIDNIGHT...MOIST SOUTHWEST WIND FLOW WILL CONTINUE IN THE
LOWER LEVELS AND IT SHOULD FAVOR MORE IFR STRATUS CEILING THAN IFR
FOG. WILL GO MAINLY MVFR VSBYS WITH FOG MOST LOCATIONS TUESDAY NEAR
DAYBREAK BUT WILL HAVE LOWER IFR VSBYS AT AGS AND OGB. AFTER 14Z
TUESDAY MORNING...CONDITIONS SHOULD HAVE IMPROVED TO VFR AGAIN BUT
SHOWERS AND THUNDERSTORMS SHOULD DEVELOP AGAIN BY TUESDAY AFTERNOON.
DUE TO UNCERTAINTY AS TO TIMING AND AERIAL COVERAGE...DECIDED TO
LEAVE MENTION OF SHOWERS AND THUNDERSTORMS OUT OF TAF SITES.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES
EAST.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
SYNOPSIS...
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07

000
FXUS62 KCAE 142322
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
722 PM EDT MON MAY 14 2012

.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
TONIGHT THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO THE
REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT OVERNIGHT...
ESPECIALLY DURING THE EVENING HOURS. DURING THE EVENING HOURS...
TEMPERATURES WILL LOWER AND THE CHANCES OF SHOWERS AND
THUNDERSTORMS WILL DECREASE. SO DECIDED TO GO 30-40 PERCENT
CHANCE OF SHOWERS AND WILL MENTION SLIGHT CHANCE OF THUNDERSTORMS.
HEAVIER SHOWERS AND THUNDERSTORMS MAY PRODUCE UP TO ONE INCH OF
RAIN. TEMPERATURES TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS
AND CLOUDS AND PRECIPITATION...GENERALLY IN THE MID 60S.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.

AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE
LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY
NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE
WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS
AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE
WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID
MORNING THROUGH EARLY AFTERNOON.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING PLENTY
OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW. SHOWERS AND
A FEW THUNDERSTORMS MAY DEVELOP NEXT 2-3 HOURS AT TAF SITES BUT WILL
LEAVE OUT MENTION OF CONVECTIVE ACTIVITY EXCEPT FOR OGB WHERE
SHOWERS OR THUNDERSTORMS ARE POSSIBLE UNTIL AROUND 01Z OR 02Z.
BUT WITH THE SUN SETTING...THE HEATING WILL BE GONE AND THE
CONVECTIVE ACTIVITY SHOULD BE OVER FOR THE NIGHT. WITH ANY SHOWER OR
THUNDERSTORM...THERE MAY BE BRIEF IFR-MVFR CONDITIONS THIS EVENING.
AFTER MIDNIGHT...MOIST SOUTHWEST WIND FLOW WILL CONTINUE IN THE
LOWER LEVELS AND IT SHOULD FAVOR MORE IFR STRATUS CEILING THAN IFR
FOG. WILL GO MAINLY MVFR VSBYS WITH FOG MOST LOCATIONS TUESDAY NEAR
DAYBREAK BUT WILL HAVE LOWER IFR VSBYS AT AGS AND OGB. AFTER 14Z
TUESDAY MORNING...CONDITIONS SHOULD HAVE IMPROVED TO VFR AGAIN BUT
SHOWERS AND THUNDERSTORMS SHOULD DEVELOP AGAIN BY TUESDAY AFTERNOON.
DUE TO UNCERTAINTY AS TO TIMING AND AERIAL COVERAGE...DECIDED TO
LEAVE MENTION OF SHOWERS AND THUNDERSTORMS OUT OF TAF SITES.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES
EAST.


&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
SYNOPSIS...
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07

000
FXUS62 KCAE 142228
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
628 PM EDT MON MAY 14 2012

.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
TONIGHT THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO THE
REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT OVERNIGHT...
ESPECIALLY DURING THE EVENING HOURS. DURING THE EVENING HOURS...
TEMPERATURES WILL LOWER AND THE CHANCES OF SHOWERS AND
THUNDERSTORMS WILL DECREASE. SO DECIDED TO GO 30-40 PERCENT
CHANCE OF SHOWERS AND WILL MENTION SLIGHT CHANCE OF THUNDERSTORMS.
HEAVIER SHOWERS AND THUNDERSTORMS MAY PRODUCE UP TO ONE INCH OF
RAIN. TEMPERATURES TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS
AND CLOUDS AND PRECIPITATION...GENERALLY IN THE MID 60S.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.

AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE
LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY
NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE
WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS
AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE
WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID
MORNING THROUGH EARLY AFTERNOON.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING
PLENTY OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW.
WITH REAL GOOD SURFACE HEATING WHERE CLOUDS HAVE BROKEN UP...
THERE IS A POTENTIAL FOR THUNDERSTORMS TO DEVELOP BUT WILL NOT
MENTION IN TAF SITES UNLESS ACTIVITY IS MOVING RIGHT AT TAF SITE.
RUC13 H5 SHOWS WEAK TROUGHINESS DURING THIS PERIOD...SO DECIDED
TO MENTION SHOWERS IN THE VICINITY FOR THE MOST PART. WILL GO
MAINLY VFR BUT BRIEF IFR TO MVFR CONDITIONS ARE POSSIBLE IN
SHOWERS AND THUNDERSTORMS. CAE 88D SHOWS MORE CONVECTION FIRING UP
BETWEEN AGS AND OGB. EXPECT ACTIVITY TO WEAKEN AS SUN GOES DOWN
AND SURFACE HEATING ENDS. AFTER MIDNIGHT...MOIST SOUTHWEST WIND
FLOW WILL CONTINUE IN THE LOWER LEVELS AND IT SHOULD FAVOR MORE
IFR STRATUS CEILING THAN IFR FOG. WILL GO MAINLY MVFR VSBYS WITH
FOG MOST LOCATIONS TUESDAY NEAR DAYBREAK BUT WILL HAVE LOWER IFR
VSBYS AT AGS AND OGB. AFTER 14Z TUESDAY MORNING...CONDITIONS
SHOULD HAVE IMPROVED TO VFR AGAIN BUT WILL KEEP SHOWER IN THE
VICINITY REMARKS AS MOISTURE AND UPPER FEATURES STILL SIMILAR TO
THOSE TODAY.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES
EAST.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
SYNOPSIS...
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07

000
FXUS62 KCAE 142054
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
454 PM EDT MON MAY 14 2012

.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPPER TROUGH STILL TO THE WEST PULLING MOISTURE ACROSS THE REGION
FROM THE SOUTH. BOTH OBSERVED AND FORECAST SOUNDINGS ARE NEARLY
MOIST ADIABATIC WHICH SHOULD ALLOW SHOWERS TO POP UP WITH THE
SLIGHTEST TRIGGER. RUC13 SHOWS WEAK TROUGH ACROSS THE REGION LATE
THIS AFTERNOON INTO THE EARLY EVENING HOURS. ALSO...STRONG
AFTERNOON SURFACE HEATING HAS ALLOW STRONG AND IN SOME CASES NEAR
SEVERE THUNDERSTORM ACTIVITY TO DEVELOP MAINLY IN THE SOUTHERN
PART OF THE FORECAST AREA. EXPECT RAINFALL AMOUNTS TO REMAIN ONE
QUARTER INCH OR LESS IN THE WESTERN MIDLANDS AND TAPER TO LESS
THAN A TENTH OF AN INCH OVER THE EASTERN MIDLANDS THROUGH THIS
AFTERNOON...MAINLY DUE TO A LACK OF FORCING.

TONIGHT...THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO
THE REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT
OVERNIGHT...ESPECIALLY DURING THE EVENING HOURS...THEREFORE WILL
CONTINUE WITH LIKELY POPS OVERNIGHT. THE PRECIPITABLE WATER AXIS
SHIFTS OVER THE FORECAST AREA OVERNIGHT AND EXPECT THE BEST
RAINFALL ACCUMULATION TO OCCUR DURING THIS PERIOD. THE WESTERN AND
NORTHERN MIDLANDS WILL LIKELY SEE THE HIGHEST AMOUNTS...POSSIBLY
UP TO AN INCH...BUT THE ENTIRE FORECAST AREA SHOULD SEE MODERATE
MEASURABLE RAINFALL THROUGH EARLY MONDAY MORNING. TEMPERATURES
TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS AND CLOUDS AND
PRECIPITATION...GENERALLY IN THE MID 60S.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.

AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE
LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY
NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE
WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS
AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE
WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID
MORNING THROUGH EARLY AFTERNOON.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING
PLENTY OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW.
WITH REAL GOOD SURFACE HEATING WHERE CLOUDS HAVE BROKEN UP...
THERE IS A POTENTIAL FOR THUNDERSTORMS TO DEVELOP BUT WILL NOT
MENTION IN TAF SITES UNLESS ACTIVITY IS MOVING RIGHT AT TAF SITE.
RUC13 H5 SHOWS WEAK TROUGHINESS DURING THIS PERIOD...SO DECIDED
TO MENTION SHOWERS IN THE VICINITY FOR THE MOST PART. WILL GO
MAINLY VFR BUT BRIEF IFR TO MVFR CONDITIONS ARE POSSIBLE IN
SHOWERS AND THUNDERSTORMS. CAE 88D SHOWS MORE CONVECTION FIRING UP
BETWEEN AGS AND OGB. EXPECT ACTIVITY TO WEAKEN AS SUN GOES DOWN
AND SURFACE HEATING ENDS. AFTER MIDNIGHT...MOIST SOUTHWEST WIND
FLOW WILL CONTINUE IN THE LOWER LEVELS AND IT SHOULD FAVOR MORE
IFR STRATUS CEILING THAN IFR FOG. WILL GO MAINLY MVFR VSBYS WITH
FOG MOST LOCATIONS TUESDAY NEAR DAYBREAK BUT WILL HAVE LOWER IFR
VSBYS AT AGS AND OGB. AFTER 14Z TUESDAY MORNING...CONDITIONS
SHOULD HAVE IMPROVED TO VFR AGAIN BUT WILL KEEP SHOWER IN THE
VICINITY REMARKS AS MOISTURE AND UPPER FEATURES STILL SIMILAR TO
THOSE TODAY.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES
EAST.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
SYNOPSIS...
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...07

000
FXUS62 KCHS 142008
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
408 PM EDT MON MAY 14 2012

.SYNOPSIS...
A BROAD AND WEAK AREA OF LOW PRESSURE AND A TRAILING COLD FRONT WILL
MOVE VERY SLOWLY TOWARD THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE
WEEK...BEFORE SHIFTING INTO THE WESTERN ATLANTIC THURSDAY. HIGH PRESSURE
WILL THEN BUILD IN FROM THE NORTH FRIDAY THROUGH MONDAY. LOW PRESSURE
COULD FORM FAR OFFSHORE IN THE WESTERN ATLANTIC IN ASSOCIATION WITH
A CLOSED LOW ALOFT SATURDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
POPS START CHANCE TO LIKELY MOST AREAS AS MESOSCALE BOUNDARIES
PRODUCED BY PREVIOUS MULTICELL THUNDERSTORMS INITIATE NEW
CONVECTION. INTO EARLY EVENING MOST NUMEROUS THUNDERSTORMS SHOULD
OCCUR ALONG/EAST OF INTERSTATE 95...AND NORTH/WEST OF THE
CHARLESTON TRI-COUNTY REGION.

IN THESE AREAS...CONDITIONS WILL REMAIN FAVORABLE FOR ISOLATED/
BRIEF PULSE SEVERE THUNDERSTORMS WITH DAMAGING WIND GUSTS AND
LARGE HAIL INTO EARLY EVENING.

AFTER DARK...DIURNAL STABILIZATION SHOULD TRANSLATE TO A STEADY
DECREASE IN THUNDERSTORM COVERAGE/INTENSITY. GIVEN THE DEEP LAYER
CYCLONIC FLOW REGIME IN PLACE...MAINTAINED ONGOING SLIGHT CHANCE
POPS ESPECIALLY N/E OVERNIGHT...BUT WOULD NOT BE SURPRISED IF
PRECIPITATION COMPLETELY DISSIPATES OVER LAND AFTER MIDNIGHT.

PATCHY FOG IS POSSIBLE WHERE HEAVY RAIN OCCURS...ESPECIALLY
IF/WHERE WINDS REMAIN LIGHT AND CLOUDS THIN OVERNIGHT...
BUT WILL DEFER DECISIONS REGARDING ADDING FOG TO PUBLIC FORECASTS
TO LATER SHIFTS.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
SOUTHWEST FLOW ALOFT WILL PERSIST THROUGH WEDNESDAY ACROSS THE AREA
IN ADVANCE OF AN UPPER LEVEL TROUGH. THE UPPER LEVEL TROUGH WILL
SWING THROUGH THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY AND ALLOW
FOR A SURFACE COLD FRONT TO MOVE THROUGH THE AREA.

DEEP MOISTURE WITH PRECIPITABLE WATER VALUES NEAR 1.5 INCHES
TUESDAY THROUGH WEDNESDAY...COMBINED WITH SOME DAYTIME HEATING AND
UPPER LEVEL DISTURBANCES EMBEDDED IN THE SOUTHWEST FLOW ALOFT WILL
AID IN THE DEVELOPMENT OF WIDELY SCATTERED TO SCATTERED MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. AT THE PRESENT TIME
IS APPEARS THAT THE BEST COVERAGE WILL BE ON WEDNESDAY AND
MAINTAINED HIGHER RAIN CHANCES THEN. CANNOT RULE OUT A FEW STRONG TO
SEVERE THUNDERSTORMS EACH DAY...BUT FEEL THAT WITH SLIGHTLY COOLER
TEMPERATURES ALOFT..THAT THERE IS A SLIGHTLY BETTER CHANCE FOR
SEVERE THUNDERSTORMS ON WEDNESDAY. HIGH TEMPERATURES WILL BE
FAIRLY CLOSE TO SEASONAL NORMS...MAINLY IN THE MID 80S AWAY FROM THE
COAST.

IT LOOKS LIKE THE MID LEVEL TROUGH AND SURFACE COLD FRONT MOVE EAST
OF THE AREA BY LATE THURSDAY...ALLOWING FOR SOME DRIER AIR TO WORK
IN FROM THE NORTHWEST. CANNOT TOTALLY RULE OUT PRECIPITATION CHANCES
THURSDAY...BUT WITH THE UPPER LEVEL TROUGH EAST OF THE
AREA...LOWERED THE THREAT FOR RAIN INTO THE SLIGHT CHANCE CATEGORY
FOR MOST LOCALS...EXCEPT THE SOUTH WHERE CHANCE POPS WERE
MAINTAINED. MORE SUNSHINE ON THURSDAY BEHIND THE FRONT WILL MOSTLY
OFFSET THE COOLING BEHIND THE FRONT AND EXPECT HIGH TEMPERATURES TO
MAINLY BE IN THE LOWER TO MID 80S AWAY FROM THE COAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE FORECAST FOR THE END OF THIS WEEK INTO THE EARLY PART OF NEXT
WEEK IS STILL SOMEWHAT UP IN THE AIR...BUT CONSENSUS SUGGESTS THAT
WE MIGHT GET BY WITH A FEW DAYS WITHOUT RAINFALL.

THE TROUGH IN THE ATLANTIC WILL CLOSE OFF DURING FRIDAY...CAUSING A
SURFACE LOW TO FORM SOMEWHERE OUT NEAR 30 NORTH AND 70 WEST. THAT
LOW LOOKS TO MEANDER WELL OFFSHORE DURING AT LEAST THE
WEEKEND...BEFORE TURNING NORTH AT SOME POINT EARLY NEXT WEEK AS THE
CLOSED LOW OPENS AND LIFTS OUT. AT THE SAME TIME...STRONG HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH. LARGE SCALE
SUBSIDENCE LOOKS TO TAKE HOLD...WHILE THE BEST LOW LEVEL CONVERGENCE
REMAINS SOUTH OF THE AREA. THIS SHOULD KEEP THE AREA GENERALLY FREE
OF RAINFALL...ALTHOUGH SOME COASTAL SHOWERS COULD CERTAINLY OCCUR.

ADDITIONALLY....A TIGHTER PRESSURE GRADIENT WILL FORM AND BREEZY
CONDITIONS WILL OCCUR EACH DAY FRIDAY THROUGH SUNDAY...ESPECIALLY
OVER OUR COASTAL COUNTIES. THE DRIER AIR MASS WILL ALLOW FOR NIGHT
TIME LOWS TO FALL INTO THE UPPER 50S ACROSS INTERIORS SECTIONS EACH
NIGHT...WHILE AMPLE INSOLATION WILL BOOST DAYTIME HIGHS INTO THE
LOWER 80S EACH AFTERNOON AWAY FROM THE COAST.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
THUNDERSTORMS WILL CONTINUE TO OCCASIONALLY IMPACT KCHS AND KSAV
UNTIL AT LEAST 21-22Z. EXPECT AMENDMENTS TO ADDRESS NEAR TERM
CONVECTIVE TRENDS. OTHERWISE...VFR EXPECTED OUTSIDE ANY
SHOWERS/TSTMS THROUGH AT LEAST THIS EVENING. ODDS FAVOR VFR
THROUGH THE NIGHT BUT BRIEF MVFR OR LOWER CONDITIONS COULD OCCUR
AT EITHER TERMINAL IF HEAVY RAIN OCCURS THIS AFTERNOON.

THUNDERSTORMS SHOULD REDEVELOP TUESDAY...ESPECIALLY IN THE
AFTERNOON...BUT PROB30 IS NOT YET JUSTIFIED PRIOR TO 18Z.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE TUESDAY PM THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO
LOW LEVEL MOISTURE AND SCATTERED SHRA/TSRA. VFR CONDITIONS WILL
RETURN BY FRIDAY.

&&

.MARINE...
THROUGH THIS EVENING...THUNDERSTORMS COULD LOCALLY ALTER
WINDS/SEAS. OUTSIDE THUNDERSTORMS TONIGHT...THE WEAK SURFACE LOW
TO THE WEST WILL DRAW SLIGHTLY CLOSER AND S/SE WINDS WILL VEER
TOWARD THE SW. OUTSIDE THUNDERSTORMS...WINDS ARE EXPECTED TO REMAIN
AT OR BELOW 15 KTS THROUGH TONIGHT. SEAS OF 2-4 FEET WITHIN
NEARSHORE WATERS AND AS HIGH AS 5 FT BEYOND 20 NM SHOULD PREVAIL.

ALTHOUGH PERIODIC SHOWERS AND T-STORMS WILL IMPACT THE COASTAL
WATERS TUESDAY THROUGH THURSDAY...THE GENERAL WIND AND WAVE
CONDITIONS WILL REMAIN WELL BELOW ANY SCA LEVELS. THAT COULD CHANGE
LATE IN THE WEEK...WITH THE POTENTIAL FOR A DECENT PINCHING OF THE
PRESSURE GRADIENT TO OCCUR. STRONG HIGH PRESSURE WILL BUILD OUT OF
THE NE STATES THURSDAY NIGHT INTO THE WEEKEND...WHILE LOW PRESSURE
FORMS FAR OFF THE SE COAST. THE RESULTING PRESSURE DIFFERENCE
BETWEEN THESE TWO FEATURES WILL BE LARGE ENOUGH TO CAUSE WINDS AND
SEAS TO LIKELY REACH HIGH ENOUGH WHERE SCA/S WILL BE REQUIRED LATER
THIS WEEK.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...MTE
LONG TERM...
AVIATION...SPR
MARINE...SPR/MTE

000
FXUS62 KFFC 141941
AFDFFC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
341 PM EDT MON MAY 14 2012


.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
A LARGE TROUGH REMAINS IN PLACE ACROSS THE SOUTHERN TWO THIRDS OF
THE UNITED STATES WHILE WEAK SHORT WAVES THAT TRANSVERSE THROUGH
THE FLOW WILL CONTINUE TO DOMINATE OUR WEATHER IN THE SHORT TERM.
OVERNIGHT TONIGHT WE SHOULD CONTINUE TO HAVE SOME CLOUDS ACROSS
THE AREA. CHANCES OF PRECIP WILL BE LOW IF NOT NIL OVERNIGHT.
EXPECT A STRATUS DECK TO MAKE ITS WAY INTO THE AREA TOMORROW NEAR
DAY BREAK. AMPLE LOW LEVEL MOISTURE EXISTS ACROSS THE PEACH STATE
FOR CHANCES OF THUNDERSTORMS TOMORROW AS A SHORT WAVE MOVES
THROUGH THE FLOW. CAPE VALUES ARE PROGGED TO BE FROM 1500 TO 2000
J/KG. DAYTIME HEATING ALONG WITH THE CAPE AND UPPER LEVEL
SHORTWAVE SHOULD LEAD TO SOME THUNDERSTORMS TOMORROW AFTERNOON.
THESE THUNDERSTORMS WILL BE MUCH LIKE THE TYPICAL SUMMERTIME
VARIETY WE EXPERIENCE DUE TO WEAK SHEAR AND FLOW ALOFT.

TUESDAY NIGHT...EXPECT CLOUDS TO START TO CLEAR OUT OF THE AREA
STARTING FROM THE NORTHWEST...AS THE UPPER LEVEL TROUGH STARTS TO
EJECT OUT TO THE EAST.

AS FOR TEMPERATURES...USED A BLEND OF THE MET AND MAV FOR THE HIGHS
AND LOWS.  DID NO OTHER TWEAKS TO THE TEMPERATURES.


GIBBS


.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HAVE MADE NO CHANGES TO THE EXTENDED. OVERALL PATTERN REMAINS THE
SAME. A FRONTAL BOUNDARY LOOKS LIKE IT MAY APPROACH THE NORTHERN
BORDER OF GEORGIA BY THE END OF THE PERIOD...BUT WILL ADD NO POPS
AT THIS TIME. THE PREVIOUS DISCUSSION IS INCLUDED BELOW.

41



PREVIOUS LONG TERM /ISSUED 420 AM EDT MON MAY 14 2012/
THREAT FOR SHOWERS AND THUNDERSTORMS CONTINUING INTO WEDNESDAY
WITH UPPER TROF STILL OVER THE AREA AND REMNANTS OF WEAK SURFACE
BOUNDARY SOMEWHERE ACROSS CENTRAL GEORGIA. EXTENDED PROGS SIMILAR
WITH AXIS OF UPPER TROF FINALLY SHIFTING EAST OF THE COUNTY
WARNING AREA THURSDAY AS A WEAK UPPER RIDGE BUILDS IN FROM THE
WEST. RIDGE LOOKS TO DOMINATE OUR AREA INTO THE WEEKEND...BUT
LATEST MODEL RUNS CONTINUE TO SHOW A COASTAL LOW DEVELOPING OFF
THE MID ATLANTIC/SOUTHEAST U.S. COAST SAT/SUN TIME FRAME WITH SOME
DEEPER MOISTURE POSSIBLY GETTING INTO PORTIONS OF EAST GEORGIA.
HAVE KEEP THE FORECAST DRY FOR NOW WITH SEVERAL MODEL RUNS YET TO
GO...AND UNCERTAINTY TO IF AND WHERE LOW WILL FORM. TEMPS
GENERALLY RUNNING NEAR NORMAL LEVELS THROUGH THE PERIOD.

49

&&


AVIATION...
18Z UPDATE...
CEILINGS SHOULD REMAIN AT VFR TODAY...MAIN CONCERN IS ISOLATED
RAIN SHOWERS THAT COULD DEVELOP. THINK CHANCES OF THUNDER ARE VERY LOW
SO DID NOT INCLUDE IN TAF. OVERNIGHT CEILINGS SHOULD LOWER AS
WELL...NOT TOO CONFIDENT ON IFR OR LIFR CONDITIONS...WOULD LIKE TO
SEE SOME MORE PRECIP FALL TODAY BEFORE LOWERING BELOW 1000 FEET.
CHANCE OF THUNDER RETURNS TOMORROW...MUCH LIKE TYPICAL SUMMERTIME
CONVECTION.

//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON THUNDER TODAY AND TOMORROW AND CEILINGS
TOMORROW AM. HIGH CONFIDENCE ALL OTHER ELEMENTS.

GIBBS

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          59  82  60  83 /  40  30  30  20
ATLANTA         61  80  62  81 /  20  30  30  20
BLAIRSVILLE     54  75  55  78 /  50  30  30  20
CARTERSVILLE    58  80  58  82 /  20  20  30  20
COLUMBUS        63  84  63  83 /   5  20  20  20
GAINESVILLE     59  79  60  82 /  40  30  30  20
MACON           61  85  61  84 /  20  30  30  20
ROME            58  81  58  82 /  30  10  30  10
PEACHTREE CITY  58  81  58  81 /  10  30  30  20
VIDALIA         66  86  66  85 /  30  30  40  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...GIBBS
LONG TERM....41
AVIATION...GIBBS

000
FXUS62 KFFC 141753 AAB
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
153 PM EDT MON MAY 14 2012



.PREV DISCUSSION... /ISSUED 1101 AM EDT MON MAY 14 2012/

UPDATE...
CURRENT RADAR LOOP SHOWS SOME ISOLATED RAIN ACROSS FAR NORTH
GEORGIA AND ACROSS EAST CENTRAL GEORGIA. EXPECT THE BEST CHANCES
FOR PRECIP TO CONTINUE TO BE IN THIS AREA AS COLD FRONT AND WEAK
SHORTWAVE MOVES TO OUR EAST TODAY. HAVE TRIMMED DOWN THE CHANCES
FOR THUNDER TO A SLIGHT CHANCE TODAY DUE TO WEAK FORCING. WHILE
CAPE VALUES ARE PROGGED TO BE CLOSE TO 1500 J/KG...DONT EXPECT
MORE THAN ISOLATED THUNDER AS CAPE PROFILE IS LONG AND SKINNY AND
PARCEL DILUTION SHOULD KEEP HYDROMETEORS FROM REACHING TOO HIGH IN
THE ATMOSPHERE. SCATTERED THUNDER COVERAGE DUE TO WEAK FORCING AND
COLD FRONT PUSHING THROUGH THE AREA.

ARG

PREV DISCUSSION... /ISSUED 739 AM EDT MON MAY 14 2012/

PREV DISCUSSION...

SHORT TERM /TODAY THROUGH TUESDAY/...
/ISSUED 420 AM EDT MON MAY 14 2012/
SFC LOW HAS MOVED INTO NORTHWEST GEORGIA WHILE AT THE UPPER LEVELS
WE STILL REMAIN ON THE EASTERN SIDE OF THE LONG WAVE TROUGH. MUCH
OF THE RAINFALL ACROSS THE CWA HAS DISSIPATED THIS MORNING AND ONLY
ISOLATED SHOWERS ACROSS THE EASTERN HALF OF THE CWA. THE HRRR
SUGGESTS THAT WE WILL REMAIN IN THIS LULL IN ACTIVITY THROUGH 12Z
BEFORE WE SEE DEVELOPMENT AGAIN DURING THE LATE MORNING.

SFC LOW ACROSS NORTHWEST GEORGIA WILL TRACK INTO THE CAROLINAS TODAY
AND TAKE WITH IT THE BEST CHANCES FOR RAIN. HOWEVER...AS WE REMAIN
IN THE TROUGHING PATTERN ALOFT...NEAR THE LOW AT THE SFC AND WITH A
COLD FRONT ACROSS THE CWA...WE WILL CONTINUE TO SEE RAIN CHANCES FOR
TODAY. ALL MODELS ARE CONSISTENT WITH GENERATING QPF FOR
TODAY...ALTHOUGH RH TIME HEIGHT CROSS SECTIONS ARE NOT AS SATURATED
AS THE PREVIOUS FEW DAYS. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS
TO DEVELOP DURING THE LATE MORNING HOURS BUT RAINFALL AMOUNTS SHOULD BE
LESS THAN A HALF INCH. BEST CHANCES FOR PRECIP REMAIN ACROSS
NORTHEAST GEORGIA...WITH LIKELY POPS...AS THE AREA IS CLOSER TO THE
SFC LOW AND HAS ADDITIONAL SUPPORT FROM OROGRAPHIC LIFT. BOTH GFS
AND NAM INDICATE 1500-2000 J/KG OF MUCAPE THIS AFTERNOON. WITH
SOME BREAKS IN THE CLOUDS POSSIBLE...MAY REALIZE MORE OF THIS
INSTABILITY TODAY SO A CHANCE OF THUNDER...MAINLY FOR THE
AFTERNOON. SPC HAS HIGHLIGHTED THE AREA IN A 5 PERCENT RISK FOR
WIND THREAT.

TONIGHT AS THE SFC LOW CONTINUES TO EXIT THE AREA...PRECIP WILL
CONTINUE TO DIMINISH. BY TUESDAY COLD FRONT WILL STILL LINGER ACROSS
THE CWA WHICH WILL ALLOW PRECIP CHANCES TO LINGER...ONLY A SLIGHT
CHANCE THOUGH. BEST CHANCES WILL REMAIN ACROSS EASTERN GA...CLOSER
TO THE COLD FRONT.

TEMPS TODAY WILL BE DEPENDENT ON IF WE SEE BREAKS IN THE CLOUDS.
WITH OVERALL CLOUD COVERAGE THOUGH...LEANED TOWARD THE COOLER SIDE
OF GUIDANCE FOR MAX TEMPS.

11

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
/ISSUED 420 AM EDT MON MAY 14 2012/
THREAT FOR SHOWERS AND THUNDERSTORMS CONTINUING INTO WEDNESDAY
WITH UPPER TROF STILL OVER THE AREA AND REMNANTS OF WEAK SURFACE
BOUNDARY SOMEWHERE ACROSS CENTRAL GEORGIA. EXTENDED PROGS SIMILAR
WITH AXIS OF UPPER TROF FINALLY SHIFTING EAST OF THE COUNTY
WARNING AREA THURSDAY AS A WEAK UPPER RIDGE BUILDS IN FROM THE
WEST. RIDGE LOOKS TO DOMINATE OUR AREA INTO THE WEEKEND...BUT
LATEST MODEL RUNS CONTINUE TO SHOW A COASTAL LOW DEVELOPING OFF
THE MID ATLANTIC/SOUTHEAST U.S. COAST SAT/SUN TIME FRAME WITH SOME
DEEPER MOISTURE POSSIBLY GETTING INTO PORTIONS OF EAST GEORGIA.
HAVE KEEP THE FORECAST DRY FOR NOW WITH SEVERAL MODEL RUNS YET TO
GO...AND UNCERTAINTY TO IF AND WHERE LOW WILL FORM. TEMPS
GENERALLY RUNNING NEAR NORMAL LEVELS THROUGH THE PERIOD.

49

.AVIATION...
18Z UPDATE...
CEILINGS SHOULD REMAIN AT VFR TODAY...MAIN CONCERN IS ISOLATED
RAIN SHOWERS THAT COULD DEVELOP. THINK CHANCES OF THUNDER ARE VERY LOW
SO DID NOT INCLUDE IN TAF. OVERNIGHT CEILINGS SHOULD LOWER AS
WELL...NOT TOO CONFIDENT ON IFR OR LIFR CONDITIONS...WOULD LIKE TO
SEE SOME MORE PRECIP FALL TODAY BEFORE LOWERING BELOW 1000 FEET.
CHANCE OF THUNDER RETURNS TOMORROW...MUCH LIKE TYPICAL SUMMERTIME
CONVECTION.

//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON THUNDER TODAY AND TOMORROW AND CEILINGS
TOMORROW AM. HIGH CONFIDENCE ALL OTHER ELEMENTS.

GIBBS

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          76  59  82  62 /  70  30  20  20
ATLANTA         75  62  81  63 /  30  20  20  20
BLAIRSVILLE     71  53  76  58 /  70  40  20  30
CARTERSVILLE    75  57  81  57 /  30  20  20  20
COLUMBUS        80  64  84  62 /  20  20  20  20
GAINESVILLE     74  59  80  62 /  70  40  20  30
MACON           81  62  85  61 /  40  20  20  20
ROME            78  59  82  59 /  30  20  20  20
PEACHTREE CITY  77  57  81  58 /  20  20  20  20
VIDALIA         83  67  85  64 /  70  40  20  20

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

AVIATION...GIBBS

000
FXUS62 KCAE 141750
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
150 PM EDT MON MAY 14 2012

.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS THROUGH MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPPER TROUGH STILL TO THE WEST PULLING MOISTURE ACROSS THE REGION
FROM THE SOUTH. BOTH OBSERVED AND FORECAST SOUNDINGS ARE NEARLY
MOIST ADIABATIC WHICH SHOULD ALLOW SHOWERS TO POP UP WITH THE
SLIGHTEST TRIGGER. RUC13 SHOWS WEAK TROUGH ACROSS THE REGION LATE
THIS AFTERNOON INTO THE EARLY EVENING HOURS. WHILE MOST THE ACTIVITY
HAS MOVED EAST...SHOWERS CAN STILL DEVELOP. CANNOT RULE OUT A
THUNDERSTORM OR TWO BUT ABUNDANT MOISTURE IS EXPECTED TO LIMIT
STRONG CONVECTIVE ACTIVITY FROM DEVELOPING. EXPECT RAINFALL AMOUNTS
TO REMAIN ONE QUARTER INCH OR LESS IN THE WESTERN MIDLANDS AND TAPER
TO LESS THAN A TENTH OF AN INCH OVER THE EASTERN MIDLANDS THROUGH
THIS AFTERNOON...MAINLY DUE TO A LACK OF FORCING.

TONIGHT...THE UPPER TROUGH WILL BE SLOW MOVING AS IT MOVES INTO
THE REGION AND WILL CONTINUE TO PROVIDE UPPER SUPPORT
OVERNIGHT...ESPECIALLY DURING THE EVENING HOURS...THEREFORE WILL
CONTINUE WITH LIKELY POPS OVERNIGHT. THE PRECIPITABLE WATER AXIS
SHIFTS OVER THE FORECAST AREA OVERNIGHT AND EXPECT THE BEST
RAINFALL ACCUMULATION TO OCCUR DURING THIS PERIOD. THE WESTERN AND
NORTHERN MIDLANDS WILL LIKELY SEE THE HIGHEST AMOUNTS...POSSIBLY
UP TO AN INCH...BUT THE ENTIRE FORECAST AREA SHOULD SEE MODERATE
MEASURABLE RAINFALL THROUGH EARLY MONDAY MORNING. TEMPERATURES
TONIGHT WILL BE LIMITED BY INCREASED DEWPOINTS AND CLOUDS AND
PRECIPITATION...GENERALLY IN THE MID 60S.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
SURFACE TROUGH WILL REMAIN ACROSS THE AREA THROUGH THE PERIOD AND
SHOULD PROVIDE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS.

AIR MASS APPEARS TO REMAIN MODERATELY MOIST AND INCREASINGLY UNSTABLE THROUGH
THE PERIOD. SOME DRYING SUGGESTED BY MODELS ESPECIALLY GFS...HOWEVER
EXPECT PRECIPITABLE WATER TO REMAIN RELATIVELY HIGH...NEAR 1.5
INCHES AT TIMES WITH PERSISTENT SOUTHWEST MOIST 850MB FLOW AHEAD
OF UPPER LEVEL TROUGH ACROSS THE MISSISSIPPI VALLEY AND MIDWEST.
SEVERAL SHORT WAVE TRIGGERS LIKELY TO ROTATE THROUGH THE
REGION...WHICH SHOULD AID THUNDERSTORM DEVELOPMENT...HOWEVER
TIMING OF WAVES DIFFICULT. FORECAST HIGH CHANCE POPS DURING THE
LATE AFTERNOON AND EVENING TUESDAY...POSSIBLY LATE INTO TUESDAY
NIGHT ASSOCIATED WITH POSSIBLE STRONGER SHORT WAVE. CHANCE
WEDNESDAY ESPECIALLY EAST MIDLANDS WHERE DEEPER MOISTURE IS
AND STRONGER UPPER LEVEL FORCING IS LOCATED. TEMPERATURES SHOULD BE
WARMER TUESDAY AND WEDNESDAY WITH SOME BREAKS IN THE OVERCAST MID
MORNING THROUGH EARLY AFTERNOON.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
UPPER TROUGH STILL TO THE WEST OF THE FORECAST AREA BRINGING
PLENTY OF MOISTURE ON LOW LEVEL SOUTH TO SOUTHWEST WIND FLOW.
AIR MASS NEARLY SATURATED WITH BOTH LAPS AND MODEL SOUNDING MOIST
ADIABATIC. THIS SHOULD LIMIT THUNDERSTORM DEVELOPMENT BUT SHOWERS
ARE EXPECTED TO DEVELOP ANY TIME THIS AFTERNOON THROUGH THE EARLY
EVENING HOURS WITH JUST A MODEST TRIGGER. RUC13 H5 SHOWS WEAK
TROUGHINESS DURING THIS PERIOD...SO DECIDED TO MENTION SHOWERS IN
THE VICINITY FOR THE MOST PART. WILL GO MAINLY VFR BUT BRIEF IFR
TO MVFR CONDITIONS ARE POSSIBLE IN JUST ABOUT ANY SHOWER.
THUNDERSTORMS ARE ALSO POSSIBLE BUT NOT CONFIDENT ENOUGH TO PUT
IN THE TAF SITES. CAE 88D SHOWS STRONGEST CONVECTIVE ACTIVITY WITH
LIGHTNING WELL EAST OF TAF SITES WITH CONVECTIVE LINE WHICH MOVED
THROUGH EARLIER THIS MORNING. ALSO...AIRMASS APPEARS MORE UNSTABLE
TO THE EAST WITH LAPS CAPES OVER 3000 J/KG AND LAPS LIS -6/-7. MORE
MODEST DYNAMICS OVER TAF SITES WITH LAPS CAPES AROUND 2000 J/KG AND
LAPS LIS AROUND -5. TREND GOOD THROUGH ABOUT MIDNIGHT TONIGHT...04Z.
SHOWERS ARE EXPECTED TO TAPER OFF BEFORE THEN THOUGH AROUND 01-02Z.
AFTER MIDNIGHT...MOIST SOUTHWEST WIND FLOW WILL CONTINUE IN THE
LOWER LEVELS AND IT SHOULD FAVOR MORE IFR STRATUS CEILING THAN IFR
FOG. WILL GO MAINLY MVFR VSBYS WITH FOG MOST LOCATIONS TUESDAY NEAR
DAYBREAK BUT WILL HAVE LOWER IFR VSBYS AT AGS AND OGB. AFTER 14Z
TUESDAY MORNING...CONDITIONS SHOULD HAVE IMPROVED TO VFR AGAIN BUT
WILL KEEP SHOWER IN THE VICINITY REMARKS AS MOISTURE AND UPPER
FEATURES STILL SIMILAR TO THOSE TODAY.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE AGAIN WEDNESDAY MORNING AS LOW PRESSURE SYSTEM SLOWLY MOVES
EAST.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KCHS 141743
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
143 PM EDT MON MAY 14 2012

.SYNOPSIS...
A BROAD AND WEAK AREA OF LOW PRESSURE AND A TRAILING COLD FRONT WILL
MOVE VERY SLOWLY TOWARD THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE
WEEK...BEFORE SHIFTING INTO THE WESTERN ATLANTIC THURSDAY. HIGH PRESSURE
WILL THEN BUILD IN FROM THE NORTH FRIDAY THROUGH MONDAY. LOW PRESSURE
COULD FORM FAR OFFSHORE IN THE WESTERN ATLANTIC IN ASSOCIATION WITH
A CLOSED LOW ALOFT SATURDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY MONDAY AFTERNOON...MULTICELL THUNDERSTORMS CONTINUED TO
DEVELOP AND ADVANCE TOWARD THE E/NE ACROSS THE REGION. CONVECTION
COVERAGE WAS GENERALLY ENHANCED ALONG A BROAD AXIS OF LOW LEVEL
CONVERGENCE EXTENDING FROM THE NE GULF OF MEXICO THROUGH THE
FORECAST AREA...WITHIN A DEEP LAYER CYCLONIC FLOW REGIME FEATURING
WEAK SHORTWAVES/UPPER DIFFLUENCE AS DEPICTED BY WATER VAPOR
IMAGERY. WITHIN THIS SYNOPTIC SCALE REGIME...THUNDERSTORM
CLUSTERS/BANDS WERE FOCUSED ALONG NUMEROUS MESOSCALE BOUNDARIES.
0-6 KM SHEAR AROUND 25 KT AND SBCAPES AS HIGH AS 1500-2500 J/KG
WILL CONTINUE TO SUPPORT AN ACTIVE CONVECTION REGIME FEATURING
MULTICELL THUNDERSTORMS THIS AFTERNOON.

MID LEVEL DRY AIR DEPICTED BY 12Z UPPER AIR OBSERVATIONS/ONGOING
WATER VAPOR IMAGERY AND MESOSCALE THUNDERSTORM/BOUNDARY
INTERACTIONS COULD BRIEFLY ENHANCE UPDRAFTS...SUPPORTING ISOLATED
PULSE SEVERE EVENTS FEATURING DAMAGING MICROBURSTS AND EVEN LARGE
HAIL. HOWEVER...WEAK MID LEVEL LAPSE RATES LESS THAN 6 C/KM AND
COVERAGE OF CLOUDS/PRECIPITATION WILL LIMIT THE OVERALL THREAT FOR
SEVERE WEATHER. ALSO...PWATS AROUND 1.5 INCH COULD SUPPORT VERY
HEAVY RAINFALL RATES. HOWEVER...THUNDERSTORMS WILL CONTINUE TO
MOVE STEADILY TOWARD THE NORTHEAST...LIMITING RESIDENCE TIME OF
HEAVY RAINFALL...AND ANY LOCALIZED FLOODING THREAT SHOULD REMAIN
LIMITED TO ECHO TRAINING SITUATIONS...IF ANY OCCUR.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...VERY LITTLE CHANGE TO THE OVERALL PATTERN FROM THE
AFTERNOON WITH THE LOSS OF DAYTIME HEATING...COVERAGE OF
SHOWERS/STORMS WILL DIMINISH AND SHOULD BECOME INCREASINGLY CONFINED
OFFSHORE. THE WEAK SURFACE LOW WILL REMAIN TO THE WEST WITH SW FLOW
IN THE LOWER LEVELS...AND WITH LINGERING MOISTURE AT LEAST ISOLATED
SHOWERS COULD CONTINUE TO DEVELOP THROUGH THE NIGHT. ANOTHER WARM
NIGHT IS ON TAP WITH LOWS ONLY REACHING THE MID TO UPPER 60S.

TUESDAY...SHORT WAVES WILL DROP INTO THE TROUGH FOUND ALIGNED NE TO
SW FROM TENNESSEE TO TEXAS...KEEPING A DEEP SW FLOW AND A FEED OF
SUB TROPICAL MOISTURE ACROSS THE SE STATES AND THE LOCAL FORECAST
AREA. AT THE SAME TIME THERE IS THE BROAD AND WEAK LOW PRESSURE
SYSTEM AND ITS ASSOCIATED COLD FRONT FOUND STRUGGLING TO MOVE EAST
INTO THE SE PART OF THE COUNTRY. WITH WEAK NVA TO PREVAIL DURING THE
FIRST PART OF THE DAY....MUCH OF OUR RAIN CHANCES WILL COME DURING
THE AFTERNOON. MUCH OF THE DRIVING FORCE FOR CONVECTION WILL COME IN
THE FORM OF DAYTIME HEATING...THE SEA BREEZE...AND ANY BOUNDARIES
THAT FORM UPSTREAM FROM THE NEARLY STATIONARY COLD FRONT FOUND JUST
THIS SIDE OF THE APPALACHIANS. PWATS ARE NEAR THE 75TH PERCENTILE FOR
MID MAY...SO CHANCE POPS ARE IN ORDER FOR MOST LOCATIONS THE SECOND
HALF OF THE DAY. ALTHOUGH MID LEVEL LAPSE RATES ARE POOR...OUR LOW
LEVEL LAPSE RATES ARE MORE FAVORABLE. SBCAPE IN AS HIGH AS 1500-2000
J/KG AND LIFTED INDICES ARE NEAR -4 OR -5. BUT WITH DRY MID LEVEL
AIR NOTED ON SOUNDINGS AND CROSS-SECTIONS...THE RISK FOR GUSTY WINDS
CAN OCCUR IN A FEW OF THE STRONGER STORMS. BUT THIS RISK I NOT
SUFFICIENT ENOUGH TO INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK. WE
DIDN/T GO AS HIGH AS THE LOW LEVEL THICKNESS FORECAST...BUT SOME
COMPRESSIONAL HEATING AHEAD OF THE UPSTREAM COLD FRONT WILL YIELD
MAX TEMPS IN THE MID AND UPPER 80S AWAY FROM THE SHORELINE.

WEDNESDAY...THE POSITIVELY TILTED TROUGH ALOFT WILL MOVE INTO CLOSER
PROXIMITY TO THE LOCAL AREA...WHILE ITS ASSOCIATED COLD FRONT MAKES
FURTHER RELUCTANT HEADWAY TOWARDS US. ACTUALLY PART OF THE FRONT
WILL MAKE IT TO THE COAST DURING THE AFTERNOON...BUT THAT/S NORTH OF
THE LOCAL AREA. THE PART OF THE FRONT WE/RE MOST CONCERNED WITH WITH
BE HESITANT IN MOVING IN...AS IT BECOMES PARALLEL TO THE FLOW ALOFT.
STILL...WITH THE FRONT IN CLOSER PROXIMITY AND CONSIDERABLE MOISTURE
YET AGAIN...WE/RE LOOKING AT A BETTER CHANCE OF SHOWERS AND
T-STORMS. THERE IS THE LEFT FRONT QUAD OF THE UPPER LEVEL JET TO
PROVIDE FORCING FOR ASCENT...AS UPPER DIVERGENCE AND DIFLUENCE
OCCURS. THIS ALONG WITH SOME COLDER MID LEVEL AIR...AS 500 TEMPS
DROP TO -13 OR -14C...WE MIGHT SEE SOME STRONG OR ISOLATED SEVERE
T-STORMS. STRONG WINDS AND MAYBE SOME HAIL WITH WET BULB NEAR 9K
FEET CAN OCCUR. HOWEVER...PROBABILITIES AND AREAL COVERAGE DOES NOT
JUSTIFY INCLUDING IN THE HAZARDOUS WEATHER OUTLOOK. TEMPS WILL AGAIN
REACH ABOVE SEASONAL NORMS.

THURSDAY...IT LOOKS LIKE THE MID LEVEL TROUGH AND SURFACE COLD FRONT
FINALLY MAKES IT INTO THE ATLANTIC. WHILE SOME DRIER AIR DOES WORK
IN FROM THE NW...THE CLOSE PROXIMITY TO THE DIFFUSE FRONT AND THE
SEA BREEZE SHOULD STILL PROVIDE US WITH SLIGHT CHANCE AND CHANCE
POPS. HOWEVER...ADJUSTMENTS TO THE RAIN CHANCES MIGHT BE NEEDED
IN LATER FORECASTS...PENDING THE TIMING OF THIS TRANSITION. LOWER
AND MIDDLE 80S WILL BE COMMON.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
THE FORECAST FOR THE END OF THIS WEEK INTO THE EARLY PART OF NEXT
WEEK IS STILL SOMEWHAT UP IN THE AIR...BUT CONSENSUS SUGGESTS THAT
WE MIGHT GET BY WITH A FEW DAYS WITHOUT RAINFALL.

THE TROUGH IN THE ATLANTIC WILL CLOSE OFF DURING FRIDAY...CAUSING A
SURFACE LOW TO FORM SOMEWHERE OUT NEAR 30 NORTH AND 70 WEST. THAT
LOW LOOKS TO MEANDER WELL OFFSHORE DURING AT LEAST THE
WEEKEND...BEFORE TURNING NORTH AT SOME POINT EARLY NEXT WEEK AS THE
CLOSED LOW OPENS AND LIFTS OUT. AT THE SAME TIME...STRONG HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH. LARGE SCALE
SUBSIDENCE LOOKS TO TAKE HOLD...WHILE THE BEST LOW LEVEL CONVERGENCE
REMAINS SOUTH OF THE AREA. THIS SHOULD KEEP THE AREA GENERALLY FREE
OF RAINFALL...ALTHOUGH SOME COASTAL SHOWERS COULD CERTAINLY OCCUR.

ADDITIONALLY....A TIGHTER PRESSURE GRADIENT WILL FORM AND BREEZY
CONDITIONS WILL OCCUR EACH DAY FRIDAY THROUGH SUNDAY...ESPECIALLY
OVER OUR COASTAL COUNTIES. THE DRIER AIR MASS WILL ALLOW FOR NIGHT
TIME LOWS TO FALL INTO THE UPPER 50S ACROSS INTERIORS SECTIONS EACH
NIGHT...WHILE AMPLE INSOLATION WILL BOOST DAYTIME HIGHS INTO THE
LOWER 80S EACH AFTERNOON AWAY FROM THE COAST.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
EARLY AFTERNOON RADAR TRENDS SUGGEST THAT THUNDERSTORMS WILL
IMPACT KCHS AND KSAV THIS AFTERNOON. WITHIN 18Z TAFS...INITIALLY
INDICATED GUSTY WINDS BUT VFR CONDITIONS WITHIN
THUNDERSTORMS...BUT EXPECT AMENDMENTS TO ADDRESS NEAR TERM
CONVECTIVE TRENDS. OTHERWISE...VFR EXPECTED OUTSIDE ANY
SHOWERS/TSTMS THIS AFTERNOON. TONIGHT...VFR THIS EVENING. ODDS
FAVOR VFR THROUGH THE NIGHT BUT BRIEF MVFR OR LOWER CONDITIONS
COULD OCCUR AT EITHER TERMINAL IF HEAVY RAIN OCCURS THIS
AFTERNOON.

THUNDERSTORMS SHOULD REDEVELOP TUESDAY...ESPECIALLY IN THE
AFTERNOON...BUT PROB30 IS NOT YET JUSTIFIED PRIOR TO 18Z.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE TUESDAY PM THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO
LOW LEVEL MOISTURE AND SCATTERED SHRA/TSRA. VFR CONDITIONS WILL
RETURN BY FRIDAY.

&&

.MARINE...
THIS AFTERNOON AND TONIGHT...AS THE WEAK SURFACE LOW TO THE WEST
DRAWS SLIGHTLY CLOSER...S/SE WINDS WILL PREVAIL...ENHANCED BY THE
SEA BREEZE THIS AFTERNOON. THEN LATE TONIGHT THE FLOW WILL VEER
TOWARD THE SOUTHWEST. ASIDE FROM GUSTS AS HIGH AS 20 KT ESPECIALLY
ON CHS HARBOR THIS AFTERNOON...WINDS ARE EXPECTED TO REMAIN AT OR
BELOW 15 KTS THROUGH TONIGHT. SEA OF 2-4 FEET WITHIN NEARSHORE
WATERS AND AS HIGH AS 5 FT BEYOND 20 NM SHOULD PREVAIL.

ALTHOUGH PERIODIC SHOWERS AND T-STORMS WILL IMPACT THE COASTAL
WATERS TUESDAY THROUGH THURSDAY...THE GENERAL WIND AND WAVE
CONDITIONS WILL REMAIN WELL BELOW ANY SCA LEVELS. THAT COULD CHANGE
LATE IN THE WEEK...WITH THE POTENTIAL FOR A DECENT PINCHING OF THE
PRESSURE GRADIENT TO OCCUR. STRONG HIGH PRESSURE WILL BUILD OUT OF
THE NE STATES THURSDAY NIGHT INTO THE WEEKEND...WHILE LOW PRESSURE
FORMS FAR OFF THE SE COAST. THE RESULTING PRESSURE DIFFERENCE
BETWEEN THESE TWO FEATURES WILL BE LARGE ENOUGH TO CAUSE WINDS AND
SEAS TO LIKELY REACH HIGH ENOUGH WHERE SCA/S WILL BE REQUIRED LATER
THIS WEEK.

&&

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

&&

$$

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

000
FXUS62 KCHS 141654
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1254 PM EDT MON MAY 14 2012

.SYNOPSIS...
A BROAD AND WEAK AREA OF LOW PRESSURE AND A TRAILING COLD FRONT WILL
MOVE VERY SLOWLY TOWARD THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE
WEEK...BEFORE SHIFTING INTO THE WESTERN ATLANTIC THURSDAY. HIGH PRESSURE
WILL THEN BUILD IN FROM THE NORTH FRIDAY THROUGH MONDAY. LOW PRESSURE
COULD FORM FAR OFFSHORE IN THE WESTERN ATLANTIC IN ASSOCIATION WITH
A CLOSED LOW ALOFT SATURDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY MONDAY AFTERNOON...THUNDERSTORMS WERE EXPANDING IN COVERAGE
ALONG AN AXIS OF LOW LEVEL CONVERGENCE ACROSS SE GA...ESPECIALLY
ALONG/EAST OF I-95. THIS BAND OF CONVECTION SHOULD CONTINUE TO
SHIFT E/NE THROUGH MID AFTERNOON...THUS RAISED POPS TO LIKELY FOR
MOST COASTAL COUNTIES.

OTHERWISE...THE DEEP LAYER CYCLONIC FLOW REGIME...WEAK UPPER DIFFLUENCE
AND WEAK SHORTWAVES REVEALED BY WATER VAPOR IMAGERY...NUMEROUS
MESOSCALE BOUNDARIES INCLUDING OUTFLOW FROM ONGOING THUNDERSTORMS
PROMOTING LOW LEVEL MASS/MOISTURE CONVERGENCE AND READILY
INITIATING DEEP MOIST UPDRAFTS...0-6 KM SHEAR AROUND 25 KT AND
SBCAPES AS HIGH AS 1500-2500 J/KG WILL CONTINUE TO SUPPORT AN
ACTIVE CONVECTION REGIME THIS AFTERNOON.

MID LEVEL DRY AIR DEPICTED BY 12Z UPPER AIR OBSERVATIONS/ONGOING
WATER VAPOR IMAGERY COULD SUPPORT ISOLATED/BRIEF DAMAGING
MICROBURSTS AND LARGE HAIL. HOWEVER...WEAK MID LEVEL LAPSE RATES
LESS THAN 6 C/KM AND COVERAGE OF CLOUDS/PRECIPITATION WILL LIMIT
THE OVERALL THREAT FOR SEVERE WEATHER. ALSO...PWATS AROUND 1.5
INCH COULD SUPPORT VERY HEAVY RAINFALL RATES. HOWEVER...THUNDERSTORMS
WILL CONTINUE TO MOVE STEADILY TOWARD THE NORTHEAST...LIMITING
RESIDENCE TIME OF HEAVY RAINFALL...AND ANY LOCALIZED FLOODING THREAT
SHOULD REMAIN LIMITED TO ECHO TRAINING SITUATIONS...IF ANY OCCUR.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...VERY LITTLE CHANGE TO THE OVERALL PATTERN FROM THE
AFTERNOON WITH THE LOSS OF DAYTIME HEATING...COVERAGE OF
SHOWERS/STORMS WILL DIMINISH AND SHOULD BECOME INCREASINGLY CONFINED
OFFSHORE. THE WEAK SURFACE LOW WILL REMAIN TO THE WEST WITH SW FLOW
IN THE LOWER LEVELS...AND WITH LINGERING MOISTURE AT LEAST ISOLATED
SHOWERS COULD CONTINUE TO DEVELOP THROUGH THE NIGHT. ANOTHER WARM
NIGHT IS ON TAP WITH LOWS ONLY REACHING THE MID TO UPPER 60S.

TUESDAY...SHORT WAVES WILL DROP INTO THE TROUGH FOUND ALIGNED NE TO
SW FROM TENNESSEE TO TEXAS...KEEPING A DEEP SW FLOW AND A FEED OF
SUB TROPICAL MOISTURE ACROSS THE SE STATES AND THE LOCAL FORECAST
AREA. AT THE SAME TIME THERE IS THE BROAD AND WEAK LOW PRESSURE
SYSTEM AND ITS ASSOCIATED COLD FRONT FOUND STRUGGLING TO MOVE EAST
INTO THE SE PART OF THE COUNTRY. WITH WEAK NVA TO PREVAIL DURING THE
FIRST PART OF THE DAY....MUCH OF OUR RAIN CHANCES WILL COME DURING
THE AFTERNOON. MUCH OF THE DRIVING FORCE FOR CONVECTION WILL COME IN
THE FORM OF DAYTIME HEATING...THE SEA BREEZE...AND ANY BOUNDARIES
THAT FORM UPSTREAM FROM THE NEARLY STATIONARY COLD FRONT FOUND JUST
THIS SIDE OF THE APPALACHIANS. PWATS ARE NEAR THE 75TH PERCENTILE FOR
MID MAY...SO CHANCE POPS ARE IN ORDER FOR MOST LOCATIONS THE SECOND
HALF OF THE DAY. ALTHOUGH MID LEVEL LAPSE RATES ARE POOR...OUR LOW
LEVEL LAPSE RATES ARE MORE FAVORABLE. SBCAPE IN AS HIGH AS 1500-2000
J/KG AND LIFTED INDICES ARE NEAR -4 OR -5. BUT WITH DRY MID LEVEL
AIR NOTED ON SOUNDINGS AND CROSS-SECTIONS...THE RISK FOR GUSTY WINDS
CAN OCCUR IN A FEW OF THE STRONGER STORMS. BUT THIS RISK I NOT
SUFFICIENT ENOUGH TO INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK. WE
DIDN/T GO AS HIGH AS THE LOW LEVEL THICKNESS FORECAST...BUT SOME
COMPRESSIONAL HEATING AHEAD OF THE UPSTREAM COLD FRONT WILL YIELD
MAX TEMPS IN THE MID AND UPPER 80S AWAY FROM THE SHORELINE.

WEDNESDAY...THE POSITIVELY TILTED TROUGH ALOFT WILL MOVE INTO CLOSER
PROXIMITY TO THE LOCAL AREA...WHILE ITS ASSOCIATED COLD FRONT MAKES
FURTHER RELUCTANT HEADWAY TOWARDS US. ACTUALLY PART OF THE FRONT
WILL MAKE IT TO THE COAST DURING THE AFTERNOON...BUT THAT/S NORTH OF
THE LOCAL AREA. THE PART OF THE FRONT WE/RE MOST CONCERNED WITH WITH
BE HESITANT IN MOVING IN...AS IT BECOMES PARALLEL TO THE FLOW ALOFT.
STILL...WITH THE FRONT IN CLOSER PROXIMITY AND CONSIDERABLE MOISTURE
YET AGAIN...WE/RE LOOKING AT A BETTER CHANCE OF SHOWERS AND
T-STORMS. THERE IS THE LEFT FRONT QUAD OF THE UPPER LEVEL JET TO
PROVIDE FORCING FOR ASCENT...AS UPPER DIVERGENCE AND DIFLUENCE
OCCURS. THIS ALONG WITH SOME COLDER MID LEVEL AIR...AS 500 TEMPS
DROP TO -13 OR -14C...WE MIGHT SEE SOME STRONG OR ISOLATED SEVERE
T-STORMS. STRONG WINDS AND MAYBE SOME HAIL WITH WET BULB NEAR 9K
FEET CAN OCCUR. HOWEVER...PROBABILITIES AND AREAL COVERAGE DOES NOT
JUSTIFY INCLUDING IN THE HAZARDOUS WEATHER OUTLOOK. TEMPS WILL AGAIN
REACH ABOVE SEASONAL NORMS.

THURSDAY...IT LOOKS LIKE THE MID LEVEL TROUGH AND SURFACE COLD FRONT
FINALLY MAKES IT INTO THE ATLANTIC. WHILE SOME DRIER AIR DOES WORK
IN FROM THE NW...THE CLOSE PROXIMITY TO THE DIFFUSE FRONT AND THE
SEA BREEZE SHOULD STILL PROVIDE US WITH SLIGHT CHANCE AND CHANCE
POPS. HOWEVER...ADJUSTMENTS TO THE RAIN CHANCES MIGHT BE NEEDED
IN LATER FORECASTS...PENDING THE TIMING OF THIS TRANSITION. LOWER
AND MIDDLE 80S WILL BE COMMON.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
THE FORECAST FOR THE END OF THIS WEEK INTO THE EARLY PART OF NEXT
WEEK IS STILL SOMEWHAT UP IN THE AIR...BUT CONSENSUS SUGGESTS THAT
WE MIGHT GET BY WITH A FEW DAYS WITHOUT RAINFALL.

THE TROUGH IN THE ATLANTIC WILL CLOSE OFF DURING FRIDAY...CAUSING A
SURFACE LOW TO FORM SOMEWHERE OUT NEAR 30 NORTH AND 70 WEST. THAT
LOW LOOKS TO MEANDER WELL OFFSHORE DURING AT LEAST THE
WEEKEND...BEFORE TURNING NORTH AT SOME POINT EARLY NEXT WEEK AS THE
CLOSED LOW OPENS AND LIFTS OUT. AT THE SAME TIME...STRONG HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH. LARGE SCALE
SUBSIDENCE LOOKS TO TAKE HOLD...WHILE THE BEST LOW LEVEL CONVERGENCE
REMAINS SOUTH OF THE AREA. THIS SHOULD KEEP THE AREA GENERALLY FREE
OF RAINFALL...ALTHOUGH SOME COASTAL SHOWERS COULD CERTAINLY OCCUR.

ADDITIONALLY....A TIGHTER PRESSURE GRADIENT WILL FORM AND BREEZY
CONDITIONS WILL OCCUR EACH DAY FRIDAY THROUGH SUNDAY...ESPECIALLY
OVER OUR COASTAL COUNTIES. THE DRIER AIR MASS WILL ALLOW FOR NIGHT
TIME LOWS TO FALL INTO THE UPPER 50S ACROSS INTERIORS SECTIONS EACH
NIGHT...WHILE AMPLE INSOLATION WILL BOOST DAYTIME HIGHS INTO THE
LOWER 80S EACH AFTERNOON AWAY FROM THE COAST.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
MIDDAY RADAR TRENDS JUSTIFY VCTS/CB AT KCHS AND KSAV INTO MID
AFTERNOON. EXPECT AMENDMENTS TO ADDRESS NEAR TERM CONVECTIVE
TRENDS. OTHERWISE...VFR EXPECTED OUTSIDE ANY SHOWERS/TSTMS THIS
AFTERNOON.

IF WE DO EXPERIENCE RAINFALL LATER TODAY...THEN THERE IS A CHANCE
OF MVFR CONDITIONS LATE TONIGHT AS WIND FIELDS SUBSIDE AND
CONSIDERABLE MOISTURE BECOMES TRAPPED BENEATH THE NOCTURNAL
INVERSION. IT/S TOO EARLY IN THE FORECAST CYCLE HOWEVER TO INCLUDE
ANYTHING WORSE THAN SCT CLOUDS AROUND 1000-1500 FT.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO LOW LEVEL
MOISTURE AND SCATTERED SHRA/TSRA. VFR CONDITIONS WILL RETURN BY
FRIDAY.

&&

.MARINE...
TODAY AND TONIGHT...AS THE WEAK SURFACE LOW TO THE WEST DRAWS
SLIGHTLY CLOSER...WINDS WILL BECOME MORE SOUTHERLY THROUGH THE DAY.
THEN LATE TONIGHT THE FLOW WILL START TURNING MORE SOUTHWESTERLY.
THE SEA BREEZE COULD GUST TO 20 KT AT TIMES ON CHS HARBOR THIS
AFTERNOON. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW
15 KTS THROUGH THE PERIOD. WAVE WATCH GUIDANCE CONTINUES TO
INITIALIZE TOO HIGH. SEA OF 2-4 FEET WITHIN NEARSHORE
WATERS AND AS HIGH AS 5 FT BEYOND 20 NM SHOULD PREVAIL.

ALTHOUGH PERIODIC SHOWERS AND T-STORMS WILL IMPACT THE COASTAL
WATERS TUESDAY THROUGH THURSDAY...THE GENERAL WIND AND WAVE
CONDITIONS WILL REMAIN WELL BELOW ANY SCA LEVELS. THAT COULD CHANGE
LATE IN THE WEEK...WITH THE POTENTIAL FOR A DECENT PINCHING OF THE
PRESSURE GRADIENT TO OCCUR. STRONG HIGH PRESSURE WILL BUILD OUT OF
THE NE STATES THURSDAY NIGHT INTO THE WEEKEND...WHILE LOW PRESSURE
FORMS FAR OFF THE SE COAST. THE RESULTING PRESSURE DIFFERENCE
BETWEEN THESE TWO FEATURES WILL BE LARGE ENOUGH TO CAUSE WINDS AND
SEAS TO LIKELY REACH HIGH ENOUGH WHERE SCA/S WILL BE REQUIRED LATER
THIS WEEK.

&&

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

&&

$$

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

000
FXUS62 KCAE 141613
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1213 PM EDT MON MAY 14 2012

.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN MAINLY ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS
THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...SHOWERS AND A FEW RUMBLES OF THUNDER CONTINUE TO MOVE
ACROSS THE EASTERN MIDLANDS WITH SCATTERED SHOWERS OVER THE
WESTERN MIDLANDS. MAIN LINE OF SHOWERS WILL EXIT THE EASTERN
MIDLANDS OVER THE NEXT COUPLE OF HOURS...HOWEVER WITH BREAKS IN
THE CLOUDS AND PLENTY OF MOISTURE REMAINING BEHIND THE LINE EXPECT
ADDITIONAL SHOWERS AND A FEW THUNDERSTORMS TO DEVELOP THROUGH THE
AFTERNOON HOURS. AS SUCH HAVE ADJUSTED POPS AND CLOUDS TO ACCOUNT
FOR CURRENT TRENDS.

PREVIOUS DISCUSSION...AN H5 SHORTWAVE TROUGH...WEAK H85 WARM
ADVECTION AND CONVERGENCE AHEAD OF THE FRONT WILL SUPPORT NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS TODAY. CLOUDINESS SHOULD LIMIT
INSTABILITY. THE NAM INDICATES MAINLY WEAK INSTABILITY WITH LAPSE
RATES NEAR MOIST ADIABATIC. ANY THUNDERSTORMS SHOULD GENERALLY BE
NON-SEVERE. HOWEVER...THE WATER VAPOR IMAGERY INDICATES SOME MID-
LEVEL DRYING SHOULD OVERSPREAD THE AREA. THIS MAY LEAD TO BREAKS
IN THE OVERCAST WITH POSSIBLE STRONGER INSTABILITY AND THE DRY AIR
COULD AID DOWNDRAFTS. THEREFORE...SEVERE THUNDERSTORMS COULD
POSSIBLY OCCUR. THE TEMPERATURE GUIDANCE WAS CLOSE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SHORTWAVE ENERGY WILL BE LIFTING AWAY FROM THE FORECAST AREA THIS
EVENING AND MID LEVEL FLOW BECOMES MORE SOUTHWESTERLY RATHER THAN
SOUTHERLY. THIS WILL SHIFT THE AXIS OF DEEPER MOISTURE NORTHEAST
OF THE FORECAST AREA AS PRECIPITABLE WATER VALUES DECREASE THROUGH
THE OVERNIGHT HOURS TO JUST OVER AN INCH BY 12Z TUESDAY. WILL
CONTINUE WITH HIGH CHANCE POPS TO START THE PERIOD WITH CHANCES OF
RAIN DIMINISHING DURING THE OVERNIGHT HOURS AS THE ATMOSPHERE
DRIES AND BECOMES MORE STABLE.

THE FORECAST AREA FALLS BETWEEN SHORTWAVES ON TUESDAY AND DO NOT
EXPECT MUCH MORE THAN ISOLATED TO SCATTERED DIURNAL CONVECTION
AS THE ATMOSPHERE DESTABILIZES. TEMPERATURES SHOULD BE A BIT
WARMER WITH SOME BREAKS IN THE CLOUDS AND MAX TEMPERATURES ARE
EXPECTED IN THE LOWER TO MID 80S.

NORTHERN STREAM ENERGY TRACKING ACROSS THE GREAT LAKES REGION LATE
TUESDAY INTO WEDNESDAY WILL PICK UP THE LINGERING LOW PRESSURE
SYSTEM OVER THE TENNESSEE VALLEY AND PUSH THAT TROUGH EASTWARD
INTO THE FORECAST AREA ON WEDNESDAY. A SURFACE COLD FRONT WILL
ALSO PUSH EAST INTO THE AREA LATE WEDNESDAY. FORECAST SOUNDINGS
INDICATE MODERATE INSTABILITY ON WEDNESDAY AND THIS COMBINED WITH
AN APPROACHING SURFACE BOUNDARY WITH UPPER LEVEL SUPPORT IN THE
FORM OF A SHORTWAVE SHOULD YIELD AT LEAST SCATTERED
CONVECTION...SOME OF WHICH COULD BECOME STRONG. 500MB TEMPERATURES
COOL TO -14C WHICH WILL AID IN ATMOSPHERIC DESTABILIZATION. WILL
CARRY MID CHANCE POPS AT THIS TIME ALTHOUGH THIS MAY NEED TO BE
INCREASED WITH FUTURE UPDATES. MOISTURE IS THE LIMITING FACTOR AS
PRECIPITABLE WATER VALUES REMAIN BELOW 1.5 INCHES BUT THERE WILL
BE ENOUGH LOW LEVEL MOISTURE IN PLACE TO SUPPORT CONVECTION. MAX
TEMPERATURES ON WEDNESDAY WILL AGAIN BE IN THE 80-85 RANGE.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
MIX OF CONDITIONS THROUGH THE TAF PERIOD. SHOWERS AND A FEW
THUNDERSTORMS CONTINUE TO MOVE ACROSS THE TAF SITES RESULTING IN
CONDITIONS BETWEEN VFR AND IFR. EXPECT MUCH OF THE AFTERNOON TO BE
MVFR AS SHOWERS DEVELOP AND CROSS THE AREA. WINDS THROUGH THE
AFTERNOON AND INTO TONIGHT WILL BE SOUTHERLY AT 8 KNOTS OR LESS.
WITH MOISTURE LINGERING THROUGH TONIGHT AND WINDS BECOMING LIGHT
AND VARIABLE OVERNIGHT WILL SEE CLOUD BASES LOWER AND PATCHY FOG
DEVELOP. THIS WILL RESULT IN LOW END MVFR AND IFR CONDITIONS INTO
TUESDAY MORNING.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE TUESDAY MORNING THROUGH WEDNESDAY AS A LOW PRESSURE
SYSTEM SLOWLY CROSSES THE REGION.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

000
FXUS62 KCHS 141550
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1150 AM EDT MON MAY 14 2012

.SYNOPSIS...
A BROAD AND WEAK AREA OF LOW PRESSURE AND A TRAILING COLD FRONT WILL
MOVE VERY SLOWLY TOWARD THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE
WEEK...BEFORE SHIFTING INTO THE WESTERN ATLANTIC THURSDAY. HIGH PRESSURE
WILL THEN BUILD IN FROM THE NORTH FRIDAY THROUGH MONDAY. LOW PRESSURE
COULD FORM FAR OFFSHORE IN THE WESTERN ATLANTIC IN ASSOCIATION WITH
A CLOSED LOW ALOFT SATURDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATE MONDAY MORNING...SHOWERS/THUNDERSTORMS WERE ALREADY EXPANDING
IN COVERAGE ACROSS THE REGION...PARTICULARLY INLAND. THE DEEP
LAYER CYCLONIC FLOW REGIME...WEAK UPPER DIFFLUENCE AND WEAK
SHORTWAVES REVEALED BY WATER VAPOR IMAGERY...NUMEROUS MESOSCALE
BOUNDARIES INCLUDING OUTFLOW FROM ONGOING THUNDERSTORMS PROMOTING
LOW LEVEL MASS/MOISTURE CONVERGENCE AND READILY INITIATING DEEP
MOIST UPDRAFTS... 0-6 KM SHEAR AROUND 25 KT AND SBCAPES AS HIGH
AS 1500-2500 J/KG WILL CONTINUE TO SUPPORT AN ACTIVE CONVECTION
REGIME THIS AFTERNOON. TAPERED POPS FROM LIKELY INLAND TO CHANCE
ALONG THE COAST.

MID LEVEL DRY AIR DEPICTED BY 12Z UPPER AIR OBSERVATIONS/ONGOING
WATER VAPOR IMAGERY COULD SUPPORT ISOLATED/BRIEF DAMAGING
MICROBURSTS AND LARGE HAIL. HOWEVER...WEAK MID LEVEL LAPSE RATES
LESS THAN 6 C/KM AND COVERAGE OF CLOUDS/PRECIPITATION WILL LIMIT
THE OVERALL THREAT FOR SEVERE WEATHER. ALSO...PWATS AROUND 1.5
INCH COULD SUPPORT VERY HEAVY RAINFALL RATES. HOWEVER...THUNDERSTORMS
WILL CONTINUE TO MOVE STEADILY TOWARD THE NORTHEAST...LIMITING
RESIDENCE TIME OF HEAVY RAINFALL...AND ANY LOCALIZED FLOODING THREAT
SHOULD REMAIN LIMITED TO ECHO TRAINING SITUATIONS...IF ANY OCCUR.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...VERY LITTLE CHANGE TO THE OVERALL PATTERN FROM THE
AFTERNOON WITH THE LOSS OF DAYTIME HEATING...COVERAGE OF
SHOWERS/STORMS WILL DIMINISH AND SHOULD BECOME INCREASINGLY CONFINED
OFFSHORE. THE WEAK SURFACE LOW WILL REMAIN TO THE WEST WITH SW FLOW
IN THE LOWER LEVELS...AND WITH LINGERING MOISTURE AT LEAST ISOLATED
SHOWERS COULD CONTINUE TO DEVELOP THROUGH THE NIGHT. ANOTHER WARM
NIGHT IS ON TAP WITH LOWS ONLY REACHING THE MID TO UPPER 60S.

TUESDAY...SHORT WAVES WILL DROP INTO THE TROUGH FOUND ALIGNED NE TO
SW FROM TENNESSEE TO TEXAS...KEEPING A DEEP SW FLOW AND A FEED OF
SUB TROPICAL MOISTURE ACROSS THE SE STATES AND THE LOCAL FORECAST
AREA. AT THE SAME TIME THERE IS THE BROAD AND WEAK LOW PRESSURE
SYSTEM AND ITS ASSOCIATED COLD FRONT FOUND STRUGGLING TO MOVE EAST
INTO THE SE PART OF THE COUNTRY. WITH WEAK NVA TO PREVAIL DURING THE
FIRST PART OF THE DAY....MUCH OF OUR RAIN CHANCES WILL COME DURING
THE AFTERNOON. MUCH OF THE DRIVING FORCE FOR CONVECTION WILL COME IN
THE FORM OF DAYTIME HEATING...THE SEA BREEZE...AND ANY BOUNDARIES
THAT FORM UPSTREAM FROM THE NEARLY STATIONARY COLD FRONT FOUND JUST
THIS SIDE OF THE APPALACHIANS. PWATS ARE NEAR THE 75TH PERCENTILE FOR
MID MAY...SO CHANCE POPS ARE IN ORDER FOR MOST LOCATIONS THE SECOND
HALF OF THE DAY. ALTHOUGH MID LEVEL LAPSE RATES ARE POOR...OUR LOW
LEVEL LAPSE RATES ARE MORE FAVORABLE. SBCAPE IN AS HIGH AS 1500-2000
J/KG AND LIFTED INDICES ARE NEAR -4 OR -5. BUT WITH DRY MID LEVEL
AIR NOTED ON SOUNDINGS AND CROSS-SECTIONS...THE RISK FOR GUSTY WINDS
CAN OCCUR IN A FEW OF THE STRONGER STORMS. BUT THIS RISK I NOT
SUFFICIENT ENOUGH TO INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK. WE
DIDN/T GO AS HIGH AS THE LOW LEVEL THICKNESS FORECAST...BUT SOME
COMPRESSIONAL HEATING AHEAD OF THE UPSTREAM COLD FRONT WILL YIELD
MAX TEMPS IN THE MID AND UPPER 80S AWAY FROM THE SHORELINE.

WEDNESDAY...THE POSITIVELY TILTED TROUGH ALOFT WILL MOVE INTO CLOSER
PROXIMITY TO THE LOCAL AREA...WHILE ITS ASSOCIATED COLD FRONT MAKES
FURTHER RELUCTANT HEADWAY TOWARDS US. ACTUALLY PART OF THE FRONT
WILL MAKE IT TO THE COAST DURING THE AFTERNOON...BUT THAT/S NORTH OF
THE LOCAL AREA. THE PART OF THE FRONT WE/RE MOST CONCERNED WITH WITH
BE HESITANT IN MOVING IN...AS IT BECOMES PARALLEL TO THE FLOW ALOFT.
STILL...WITH THE FRONT IN CLOSER PROXIMITY AND CONSIDERABLE MOISTURE
YET AGAIN...WE/RE LOOKING AT A BETTER CHANCE OF SHOWERS AND
T-STORMS. THERE IS THE LEFT FRONT QUAD OF THE UPPER LEVEL JET TO
PROVIDE FORCING FOR ASCENT...AS UPPER DIVERGENCE AND DIFLUENCE
OCCURS. THIS ALONG WITH SOME COLDER MID LEVEL AIR...AS 500 TEMPS
DROP TO -13 OR -14C...WE MIGHT SEE SOME STRONG OR ISOLATED SEVERE
T-STORMS. STRONG WINDS AND MAYBE SOME HAIL WITH WET BULB NEAR 9K
FEET CAN OCCUR. HOWEVER...PROBABILITIES AND AREAL COVERAGE DOES NOT
JUSTIFY INCLUDING IN THE HAZARDOUS WEATHER OUTLOOK. TEMPS WILL AGAIN
REACH ABOVE SEASONAL NORMS.

THURSDAY...IT LOOKS LIKE THE MID LEVEL TROUGH AND SURFACE COLD FRONT
FINALLY MAKES IT INTO THE ATLANTIC. WHILE SOME DRIER AIR DOES WORK
IN FROM THE NW...THE CLOSE PROXIMITY TO THE DIFFUSE FRONT AND THE
SEA BREEZE SHOULD STILL PROVIDE US WITH SLIGHT CHANCE AND CHANCE
POPS. HOWEVER...ADJUSTMENTS TO THE RAIN CHANCES MIGHT BE NEEDED
IN LATER FORECASTS...PENDING THE TIMING OF THIS TRANSITION. LOWER
AND MIDDLE 80S WILL BE COMMON.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
THE FORECAST FOR THE END OF THIS WEEK INTO THE EARLY PART OF NEXT
WEEK IS STILL SOMEWHAT UP IN THE AIR...BUT CONSENSUS SUGGESTS THAT
WE MIGHT GET BY WITH A FEW DAYS WITHOUT RAINFALL.

THE TROUGH IN THE ATLANTIC WILL CLOSE OFF DURING FRIDAY...CAUSING A
SURFACE LOW TO FORM SOMEWHERE OUT NEAR 30 NORTH AND 70 WEST. THAT
LOW LOOKS TO MEANDER WELL OFFSHORE DURING AT LEAST THE
WEEKEND...BEFORE TURNING NORTH AT SOME POINT EARLY NEXT WEEK AS THE
CLOSED LOW OPENS AND LIFTS OUT. AT THE SAME TIME...STRONG HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH. LARGE SCALE
SUBSIDENCE LOOKS TO TAKE HOLD...WHILE THE BEST LOW LEVEL CONVERGENCE
REMAINS SOUTH OF THE AREA. THIS SHOULD KEEP THE AREA GENERALLY FREE
OF RAINFALL...ALTHOUGH SOME COASTAL SHOWERS COULD CERTAINLY OCCUR.

ADDITIONALLY....A TIGHTER PRESSURE GRADIENT WILL FORM AND BREEZY
CONDITIONS WILL OCCUR EACH DAY FRIDAY THROUGH SUNDAY...ESPECIALLY
OVER OUR COASTAL COUNTIES. THE DRIER AIR MASS WILL ALLOW FOR NIGHT
TIME LOWS TO FALL INTO THE UPPER 50S ACROSS INTERIORS SECTIONS EACH
NIGHT...WHILE AMPLE INSOLATION WILL BOOST DAYTIME HIGHS INTO THE
LOWER 80S EACH AFTERNOON AWAY FROM THE COAST.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
MIDDAY RADAR TRENDS JUSTIFY VCTS/CB AT KCHS AND KSAV INTO MID
AFTERNOON. EXPECT AMENDMENTS TO ADDRESS NEAR TERM CONVECTIVE
TRENDS. OTHERWISE...VFR EXPECTED OUTSIDE ANY SHOWERS/TSTMS THIS
AFTERNOON.

IF WE DO EXPERIENCE RAINFALL LATER TODAY...THEN THERE IS A CHANCE
OF MVFR CONDITIONS LATE TONIGHT AS WIND FIELDS SUBSIDE AND
CONSIDERABLE MOISTURE BECOMES TRAPPED BENEATH THE NOCTURNAL
INVERSION. IT/S TOO EARLY IN THE FORECAST CYCLE HOWEVER TO INCLUDE
ANYTHING WORSE THAN SCT CLOUDS AROUND 1000-1500 FT.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO LOW LEVEL
MOISTURE AND SCATTERED SHRA/TSRA. VFR CONDITIONS WILL RETURN BY
FRIDAY.

&&

.MARINE...
TODAY AND TONIGHT...AS THE WEAK SURFACE LOW TO THE WEST DRAWS
SLIGHTLY CLOSER...WINDS WILL BECOME MORE SOUTHERLY THROUGH THE DAY.
THEN LATE TONIGHT THE FLOW WILL START TURNING MORE SOUTHWESTERLY.
THE SEA BREEZE COULD GUST TO 20 KT AT TIMES ON CHS HARBOR THIS
AFTERNOON. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW
15 KTS THROUGH THE PERIOD. WAVE WATCH GUIDANCE CONTINUES TO
INITIALIZE TOO HIGH. SEA OF 2-4 FEET WITHIN NEARSHORE
WATERS AND AS HIGH AS 5 FT BEYOND 20 NM SHOULD PREVAIL.

ALTHOUGH PERIODIC SHOWERS AND T-STORMS WILL IMPACT THE COASTAL
WATERS TUESDAY THROUGH THURSDAY...THE GENERAL WIND AND WAVE
CONDITIONS WILL REMAIN WELL BELOW ANY SCA LEVELS. THAT COULD CHANGE
LATE IN THE WEEK...WITH THE POTENTIAL FOR A DECENT PINCHING OF THE
PRESSURE GRADIENT TO OCCUR. STRONG HIGH PRESSURE WILL BUILD OUT OF
THE NE STATES THURSDAY NIGHT INTO THE WEEKEND...WHILE LOW PRESSURE
FORMS FAR OFF THE SE COAST. THE RESULTING PRESSURE DIFFERENCE
BETWEEN THESE TWO FEATURES WILL BE LARGE ENOUGH TO CAUSE WINDS AND
SEAS TO LIKELY REACH HIGH ENOUGH WHERE SCA/S WILL BE REQUIRED LATER
THIS WEEK.

&&

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

&&

$$

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

000
FXUS62 KFFC 141501 AAA
AFDFFC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1101 AM EDT MON MAY 14 2012

.UPDATE...
CURRENT RADAR LOOP SHOWS SOME ISOLATED RAIN ACROSS FAR NORTH
GEORGIA AND ACROSS EAST CENTRAL GEORGIA. EXPECT THE BEST CHANCES
FOR PRECIP TO CONTINUE TO BE IN THIS AREA AS COLD FRONT AND WEAK
SHORTWAVE MOVES TO OUR EAST TODAY. HAVE TRIMMED DOWN THE CHANCES
FOR THUNDER TO A SLIGHT CHANCE TODAY DUE TO WEAK FORCING. WHILE
CAPE VALUES ARE PROGGED TO BE CLOSE TO 1500 J/KG...DONT EXPECT
MORE THAN ISOLATED THUNDER AS CAPE PROFILE IS LONG AND SKINNY AND
PARCEL DILUTION SHOULD KEEP HYDROMETEORS FROM REACHING TOO HIGH IN
THE ATMOSPHERE. SCATTERED THUNDER COVERAGE DUE TO WEAK FORCING AND
COLD FRONT PUSHING THROUGH THE AREA.

ARG

&&


.PREV DISCUSSION... /ISSUED 739 AM EDT MON MAY 14 2012/

PREV DISCUSSION...

SHORT TERM /TODAY THROUGH TUESDAY/...
/ISSUED 420 AM EDT MON MAY 14 2012/
SFC LOW HAS MOVED INTO NORTHWEST GEORGIA WHILE AT THE UPPER LEVELS
WE STILL REMAIN ON THE EASTERN SIDE OF THE LONG WAVE TROUGH. MUCH
OF THE RAINFALL ACROSS THE CWA HAS DISSIPATED THIS MORNING AND ONLY
ISOLATED SHOWERS ACROSS THE EASTERN HALF OF THE CWA. THE HRRR
SUGGESTS THAT WE WILL REMAIN IN THIS LULL IN ACTIVITY THROUGH 12Z
BEFORE WE SEE DEVELOPMENT AGAIN DURING THE LATE MORNING.

SFC LOW ACROSS NORTHWEST GEORGIA WILL TRACK INTO THE CAROLINAS TODAY
AND TAKE WITH IT THE BEST CHANCES FOR RAIN. HOWEVER...AS WE REMAIN
IN THE TROUGHING PATTERN ALOFT...NEAR THE LOW AT THE SFC AND WITH A
COLD FRONT ACROSS THE CWA...WE WILL CONTINUE TO SEE RAIN CHANCES FOR
TODAY. ALL MODELS ARE CONSISTENT WITH GENERATING QPF FOR
TODAY...ALTHOUGH RH TIME HEIGHT CROSS SECTIONS ARE NOT AS SATURATED
AS THE PREVIOUS FEW DAYS. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS
TO DEVELOP DURING THE LATE MORNING HOURS BUT RAINFALL AMOUNTS SHOULD BE
LESS THAN A HALF INCH. BEST CHANCES FOR PRECIP REMAIN ACROSS
NORTHEAST GEORGIA...WITH LIKELY POPS...AS THE AREA IS CLOSER TO THE
SFC LOW AND HAS ADDITIONAL SUPPORT FROM OROGRAPHIC LIFT. BOTH GFS
AND NAM INDICATE 1500-2000 J/KG OF MUCAPE THIS AFTERNOON. WITH
SOME BREAKS IN THE CLOUDS POSSIBLE...MAY REALIZE MORE OF THIS
INSTABILITY TODAY SO A CHANCE OF THUNDER...MAINLY FOR THE
AFTERNOON. SPC HAS HIGHLIGHTED THE AREA IN A 5 PERCENT RISK FOR
WIND THREAT.

TONIGHT AS THE SFC LOW CONTINUES TO EXIT THE AREA...PRECIP WILL
CONTINUE TO DIMINISH. BY TUESDAY COLD FRONT WILL STILL LINGER ACROSS
THE CWA WHICH WILL ALLOW PRECIP CHANCES TO LINGER...ONLY A SLIGHT
CHANCE THOUGH. BEST CHANCES WILL REMAIN ACROSS EASTERN GA...CLOSER
TO THE COLD FRONT.

TEMPS TODAY WILL BE DEPENDENT ON IF WE SEE BREAKS IN THE CLOUDS.
WITH OVERALL CLOUD COVERAGE THOUGH...LEANED TOWARD THE COOLER SIDE
OF GUIDANCE FOR MAX TEMPS.

11

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
/ISSUED 420 AM EDT MON MAY 14 2012/
THREAT FOR SHOWERS AND THUNDERSTORMS CONTINUING INTO WEDNESDAY
WITH UPPER TROF STILL OVER THE AREA AND REMNANTS OF WEAK SURFACE
BOUNDARY SOMEWHERE ACROSS CENTRAL GEORGIA. EXTENDED PROGS SIMILAR
WITH AXIS OF UPPER TROF FINALLY SHIFTING EAST OF THE COUNTY
WARNING AREA THURSDAY AS A WEAK UPPER RIDGE BUILDS IN FROM THE
WEST. RIDGE LOOKS TO DOMINATE OUR AREA INTO THE WEEKEND...BUT
LATEST MODEL RUNS CONTINUE TO SHOW A COASTAL LOW DEVELOPING OFF
THE MID ATLANTIC/SOUTHEAST U.S. COAST SAT/SUN TIME FRAME WITH SOME
DEEPER MOISTURE POSSIBLY GETTING INTO PORTIONS OF EAST GEORGIA.
HAVE KEEP THE FORECAST DRY FOR NOW WITH SEVERAL MODEL RUNS YET TO
GO...AND UNCERTAINTY TO IF AND WHERE LOW WILL FORM. TEMPS
GENERALLY RUNNING NEAR NORMAL LEVELS THROUGH THE PERIOD.

49

AVIATION...
12Z UPDATE...
DZ HAS DEVELOPED ACROSS THE AREA AND CIGS HAVE CONTINUED TO
LOWER...IFR TO LIFR CIGS WITH VSBYS ALSO DECREASING. ALTHOUGH
SHOWING IMPROVEMENT LATE THIS MORNING IN THE CLOUDS...IT IS
POSSIBLE LOWER CIGS WILL HOLD ON LONGER THAN EXPECTED. EVEN WITH
-DZ THIS MORNING BEST CHANCE OF -SHRA REMAINS IN THE AFTERNOON
WITH A CHANCE OF THUNDER. WINDS HAVE ALREADY SHOWN SOME INDICATION
OF SW AND HAVE DECIDED TO START ATL WITH SW WINDS...HOWEVER WINDS
COULD WOBBLE ON EITHER SIDE OF 180 THIS MORNING FOR A FEW HOURS
BUT SHOULD BE AROUND 5KTS.

//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON ALL ELEMENTS EXCEPT LOW CONFIDENCE ON THUNDER
OCCURRING THIS AFTERNOON.

11

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          76  59  82  62 /  60  30  20  20
ATLANTA         75  62  81  63 /  40  20  20  20
BLAIRSVILLE     71  53  76  58 /  60  40  20  30
CARTERSVILLE    75  57  81  57 /  50  20  20  20
COLUMBUS        80  64  84  62 /  40  20  20  20
GAINESVILLE     74  59  80  62 /  60  40  20  30
MACON           81  62  85  61 /  40  20  20  20
ROME            78  59  82  59 /  50  20  20  20
PEACHTREE CITY  77  57  81  58 /  40  20  20  20
VIDALIA         83  67  85  64 /  40  40  20  20

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

ARG

000
FXUS62 KCHS 141329
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
929 AM EDT MON MAY 14 2012

.SYNOPSIS...
A BROAD AND WEAK AREA OF LOW PRESSURE AND A TRAILING COLD FRONT WILL
MOVE VERY SLOWLY TOWARD THE SOUTHEAST COAST THROUGH THE MIDDLE OF THE
WEEK...BEFORE SHIFTING INTO THE WESTERN ATLANTIC THURSDAY. HIGH PRESSURE
WILL THEN BUILD IN FROM THE NORTH FRIDAY THROUGH MONDAY. LOW PRESSURE
COULD FORM FAR OFFSHORE IN THE WESTERN ATLANTIC IN ASSOCIATION WITH
A CLOSED LOW ALOFT SATURDAY THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MONDAY MORNING...UPDATED FORECASTS TO ACCOUNT FOR RADAR TRENDS
THROUGH MIDDAY. IN PARTICULAR...SHOWERS/ISOLATED THUNDERSTORMS
WERE PUSHING NE ALONG THE COAST.

TODAY...THE FORECAST AREA WILL REMAIN WITHIN AN AREA OF SW FLOW
ALOFT WITHIN THE EASTERN PERIPHERY OF THE BROAD TROF THAT
ENCOMPASSES MUCH OF THE SOUTHERN CONUS. AT THE SURFACE...THE WEAK
SURFACE LOW LOCATED NEAR THE SOUTHERN END OF THE APPALACHIANS WILL
MAKE MINIMAL MOVEMENT TO THE NORTHEAST WHICH WILL LEAVE THE REGION
IN AREA OF LOW LEVEL FLOW THAT TURNS MORE SOUTHERLY WITH TIME. THE
MAIN FORECAST PROBLEM FOR THE DAY REVOLVES AROUND THE POTENTIAL FOR
SHOWER/THUNDERSTORM DEVELOPMENT AND THE EVENTUAL AREAL COVERAGE.
GIVEN THAT VIRTUALLY ALL NEAR TERM MESOSCALE MODEL GUIDANCE IS DOING
A POOR JOB INITIALIZING WHAT IS GOING ON CURRENTLY...ITS HARD TO PUT
MUCH CONFIDENCE IN THEIR SOLUTIONS FOR THIS AFTERNOON. PER 12Z
SOUNDINGS...A RELATIVELY MOIST AIRMASS REMAIN IN PLACE WITH PWATS
AROUND 1.4-1.5 INCHES AND SW FLOW ALOFT WITH ONLY WEAK SHORTWAVE
DISTURBANCES PROGGED TO MOVE OVER THE REGION. LOW LEVEL
THICKNESSES AND TEMPERATURES ARE EXPECTED TO BE WARMER THAN ON
SUNDAY...AND MODIFIED 12Z SOUNDINGS YIELD SBCAPES AROUND 1500 J/KG.
THUS...IT APPEARS THAT PRECIP TODAY WILL BE PRIMARILY GENERATED BY
MODERATE SURFACE BASED INSTABILITY AND DIURNAL HEATING. MAINTAINED
ONGOING HIGH CHANCE POPS ACROSS MOST OF THE INLAND AREAS...WITH JUST A
SMALL TIER OF LIKELY POPS ACROSS THE MOST NORTHERN AREAS ACROSS
SOUTHERN SC. CONCERNING THE POTENTIAL FOR STRONG TO SEVERE
STORMS...THE OVERALL THREAT APPEARS LOW. HOWEVER MODEL TIME
HEIGHTS...AS WELL AS WATER VAPOR IMAGERY...SHOW INCREASINGLY DRY
MID/UPPER LEVELS THROUGH THE DAY AS A DRY SLOT WORKS ITS WAY IN
FROM THE WEST. THIS MAY ALLOW FOR A FEW STRONGER STORMS TO DEVELOP
IN AREAS THAT SEE THE BEST SURFACE HEATING...BUT STILL FEEL THE
OVERALL THREAT IS LOW ENOUGH TO LEAVE OUT OF THE HWO FOR NOW.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...VERY LITTLE CHANGE TO THE OVERALL PATTERN FROM THE
AFTERNOON WITH THE LOSS OF DAYTIME HEATING...COVERAGE OF
SHOWERS/STORMS WILL DIMINISH AND SHOULD BECOME INCREASINGLY CONFINED
OFFSHORE. THE WEAK SURFACE LOW WILL REMAIN TO THE WEST WITH SW FLOW
IN THE LOWER LEVELS...AND WITH LINGERING MOISTURE AT LEAST ISOLATED
SHOWERS COULD CONTINUE TO DEVELOP THROUGH THE NIGHT. ANOTHER WARM
NIGHT IS ON TAP WITH LOWS ONLY REACHING THE MID TO UPPER 60S.

TUESDAY...SHORT WAVES WILL DROP INTO THE TROUGH FOUND ALIGNED NE TO
SW FROM TENNESSEE TO TEXAS...KEEPING A DEEP SW FLOW AND A FEED OF
SUB TROPICAL MOISTURE ACROSS THE SE STATES AND THE LOCAL FORECAST
AREA. AT THE SAME TIME THERE IS THE BROAD AND WEAK LOW PRESSURE
SYSTEM AND ITS ASSOCIATED COLD FRONT FOUND STRUGGLING TO MOVE EAST
INTO THE SE PART OF THE COUNTRY. WITH WEAK NVA TO PREVAIL DURING THE
FIRST PART OF THE DAY....MUCH OF OUR RAIN CHANCES WILL COME DURING
THE AFTERNOON. MUCH OF THE DRIVING FORCE FOR CONVECTION WILL COME IN
THE FORM OF DAYTIME HEATING...THE SEA BREEZE...AND ANY BOUNDARIES
THAT FORM UPSTREAM FROM THE NEARLY STATIONARY COLD FRONT FOUND JUST
THIS SIDE OF THE APPALACHIANS. PWATS ARE NEAR THE 75TH PERCENTILE FOR
MID MAY...SO CHANCE POPS ARE IN ORDER FOR MOST LOCATIONS THE SECOND
HALF OF THE DAY. ALTHOUGH MID LEVEL LAPSE RATES ARE POOR...OUR LOW
LEVEL LAPSE RATES ARE MORE FAVORABLE. SBCAPE IN AS HIGH AS 1500-2000
J/KG AND LIFTED INDICES ARE NEAR -4 OR -5. BUT WITH DRY MID LEVEL
AIR NOTED ON SOUNDINGS AND CROSS-SECTIONS...THE RISK FOR GUSTY WINDS
CAN OCCUR IN A FEW OF THE STRONGER STORMS. BUT THIS RISK I NOT
SUFFICIENT ENOUGH TO INCLUDE IN THE HAZARDOUS WEATHER OUTLOOK. WE
DIDN/T GO AS HIGH AS THE LOW LEVEL THICKNESS FORECAST...BUT SOME
COMPRESSIONAL HEATING AHEAD OF THE UPSTREAM COLD FRONT WILL YIELD
MAX TEMPS IN THE MID AND UPPER 80S AWAY FROM THE SHORELINE.

WEDNESDAY...THE POSITIVELY TILTED TROUGH ALOFT WILL MOVE INTO CLOSER
PROXIMITY TO THE LOCAL AREA...WHILE ITS ASSOCIATED COLD FRONT MAKES
FURTHER RELUCTANT HEADWAY TOWARDS US. ACTUALLY PART OF THE FRONT
WILL MAKE IT TO THE COAST DURING THE AFTERNOON...BUT THAT/S NORTH OF
THE LOCAL AREA. THE PART OF THE FRONT WE/RE MOST CONCERNED WITH WITH
BE HESITANT IN MOVING IN...AS IT BECOMES PARALLEL TO THE FLOW ALOFT.
STILL...WITH THE FRONT IN CLOSER PROXIMITY AND CONSIDERABLE MOISTURE
YET AGAIN...WE/RE LOOKING AT A BETTER CHANCE OF SHOWERS AND
T-STORMS. THERE IS THE LEFT FRONT QUAD OF THE UPPER LEVEL JET TO
PROVIDE FORCING FOR ASCENT...AS UPPER DIVERGENCE AND DIFLUENCE
OCCURS. THIS ALONG WITH SOME COLDER MID LEVEL AIR...AS 500 TEMPS
DROP TO -13 OR -14C...WE MIGHT SEE SOME STRONG OR ISOLATED SEVERE
T-STORMS. STRONG WINDS AND MAYBE SOME HAIL WITH WET BULB NEAR 9K
FEET CAN OCCUR. HOWEVER...PROBABILITIES AND AREAL COVERAGE DOES NOT
JUSTIFY INCLUDING IN THE HAZARDOUS WEATHER OUTLOOK. TEMPS WILL AGAIN
REACH ABOVE SEASONAL NORMS.

THURSDAY...IT LOOKS LIKE THE MID LEVEL TROUGH AND SURFACE COLD FRONT
FINALLY MAKES IT INTO THE ATLANTIC. WHILE SOME DRIER AIR DOES WORK
IN FROM THE NW...THE CLOSE PROXIMITY TO THE DIFFUSE FRONT AND THE
SEA BREEZE SHOULD STILL PROVIDE US WITH SLIGHT CHANCE AND CHANCE
POPS. HOWEVER...ADJUSTMENTS TO THE RAIN CHANCES MIGHT BE NEEDED
IN LATER FORECASTS...PENDING THE TIMING OF THIS TRANSITION. LOWER
AND MIDDLE 80S WILL BE COMMON.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
THE FORECAST FOR THE END OF THIS WEEK INTO THE EARLY PART OF NEXT
WEEK IS STILL SOMEWHAT UP IN THE AIR...BUT CONSENSUS SUGGESTS THAT
WE MIGHT GET BY WITH A FEW DAYS WITHOUT RAINFALL.

THE TROUGH IN THE ATLANTIC WILL CLOSE OFF DURING FRIDAY...CAUSING A
SURFACE LOW TO FORM SOMEWHERE OUT NEAR 30 NORTH AND 70 WEST. THAT
LOW LOOKS TO MEANDER WELL OFFSHORE DURING AT LEAST THE
WEEKEND...BEFORE TURNING NORTH AT SOME POINT EARLY NEXT WEEK AS THE
CLOSED LOW OPENS AND LIFTS OUT. AT THE SAME TIME...STRONG HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH. LARGE SCALE
SUBSIDENCE LOOKS TO TAKE HOLD...WHILE THE BEST LOW LEVEL CONVERGENCE
REMAINS SOUTH OF THE AREA. THIS SHOULD KEEP THE AREA GENERALLY FREE
OF RAINFALL...ALTHOUGH SOME COASTAL SHOWERS COULD CERTAINLY OCCUR.

ADDITIONALLY....A TIGHTER PRESSURE GRADIENT WILL FORM AND BREEZY
CONDITIONS WILL OCCUR EACH DAY FRIDAY THROUGH SUNDAY...ESPECIALLY
OVER OUR COASTAL COUNTIES. THE DRIER AIR MASS WILL ALLOW FOR NIGHT
TIME LOWS TO FALL INTO THE UPPER 50S ACROSS INTERIORS SECTIONS EACH
NIGHT...WHILE AMPLE INSOLATION WILL BOOST DAYTIME HIGHS INTO THE
LOWER 80S EACH AFTERNOON AWAY FROM THE COAST.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
THE LIGHT SE FLOW THIS MORNING WILL GRADUALLY TURN MORE SOUTHERLY
AND INCREASE IN SPEEDS DURING THE LATE MORNING AND THIS
AFTERNOON...AS A WEAK SURFACE LOW DRAWS CLOSER FROM THE WEST.
ISOLATED SHRA WILL SKIRT THE KSAV TERMINAL THROUGH MID
MORNING...BEFORE ANOTHER ROUND OF PERIODIC SHOWERS AND SCATTERED
THUNDERSTORMS WILL OCCUR ACROSS A BROADER REGION THIS AFTERNOON.
HOWEVER WITHOUT ANY LARGER SCALE FEATURE TO HANG ON
TO...CONFIDENCE IN SPECIFIC TIMING FOR SHOWERS AND/OR
THUNDERSTORMS IS LOW. AS SUCH I HAVE NOT MENTIONED THUNDER IN THE
TAFS AND INSTEAD HAVE GONE WITH A SEVERAL HOUR PERIOD OF
PREVAILING SHOWERS STARTING IN THE EARLY AFTERNOON. LOW END VFR
CIGS ARE EXPECTED TO PREVAIL THROUGH THE DAY...ALTHOUGH SHOULD ANY
CONVECTION IMPACT EITHER TERMINAL...THEN OCCASIONAL MVFR WEATHER
CAN OCCUR.

IF WE DO EXPERIENCE RAINFALL LATER TODAY...THEN THERE IS A CHANCE
OF MVFR CONDITIONS LATE TONIGHT AS WIND FIELDS SUBSIDE AND
CONSIDERABLE MOISTURE BECOMES TRAPPED BENEATH THE NOCTURNAL
INVERSION. IT/S TOO EARLY IN THE FORECAST CYCLE HOWEVER TO INCLUDE
ANYTHING WORSE THAN SCT CLOUDS AROUND 1000-1500 FT.

EXTENDED AVIATION OUTLOOK...PERIODIC MVFR OR LOWER CONDITIONS WILL BE
POSSIBLE THROUGH WEDNESDAY OR PERHAPS THURSDAY DUE TO LOW LEVEL
MOISTURE AND SCATTERED SHRA/TSRA. VFR CONDITIONS WILL RETURN BY
FRIDAY.

&&

.MARINE...
TODAY AND TONIGHT...AS THE WEAK SURFACE LOW TO THE WEST DRAWS
SLIGHTLY CLOSER...WINDS WILL BECOME MORE SOUTHERLY THROUGH THE DAY.
THEN LATE TONIGHT THE FLOW WILL START TURNING MORE SOUTHWESTERLY.
WINDS ARE EXPECTED TO REMAIN AT OR BELOW 15 KTS THROUGH THE PERIOD.
WAVE WATCH GUIDANCE CONTINUES TO INITIALIZE TOO HIGH...ADVERTISING
SEAS UP TO 6 FEET BEYOND 20 NM. I HAVE ADJUSTED THIS TO REFLECT 2-4
FEET FOR THE NEARSHORE WATERS...AND 4-5 FOR THE OUTER WATERS.

ALTHOUGH PERIODIC SHOWERS AND T-STORMS WILL IMPACT THE COASTAL
WATERS TUESDAY THROUGH THURSDAY...THE GENERAL WIND AND WAVE
CONDITIONS WILL REMAIN WELL BELOW ANY SCA LEVELS. THAT COULD CHANGE
LATE IN THE WEEK...WITH THE POTENTIAL FOR A DECENT PINCHING OF THE
PRESSURE GRADIENT TO OCCUR. STRONG HIGH PRESSURE WILL BUILD OUT OF
THE NE STATES THURSDAY NIGHT INTO THE WEEKEND...WHILE LOW PRESSURE
FORMS FAR OFF THE SE COAST. THE RESULTING PRESSURE DIFFERENCE
BETWEEN THESE TWO FEATURES WILL BE LARGE ENOUGH TO CAUSE WINDS AND
SEAS TO LIKELY REACH HIGH ENOUGH WHERE SCA/S WILL BE REQUIRED LATER
THIS WEEK.

&&

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

&&

$$

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

000
FXUS62 KCAE 141300
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
900 AM EDT MON MAY 14 2012

.SYNOPSIS...
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY MOVE EAST
ACROSS THE REGION THROUGH TONIGHT. HIGH MOISTURE WILL CONTINUE AHEAD
OF THIS SYSTEM. SOME DRYING IS EXPECTED TUESDAY WHICH WILL RESULT
IN MAINLY ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS
THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...WSR-88D AND SATELLITE IMAGERY SHOW A LINE OF SHOWERS
MOVING THROUGH THE WESTERN MIDLANDS WITH SOME ADDITIONAL CELLS
DEVELOPING AHEAD OF THE LINE. WILL ISSUE AN UPDATE TO ADJUST POPS
AND CLOUDS TO REPRESENT CURRENT TRENDS. HAVE ALSO LOWERED HIGH
TEMPERATURES A FEW DEGREES AS CLOUDY SKIES WILL BLANKET THE AREA
TODAY.

PREVIOUS DISCUSSION...AN H5 SHORTWAVE TROUGH...WEAK H85 WARM
ADVECTION AND CONVERGENCE AHEAD OF THE FRONT WILL SUPPORT NUMEROUS
SHOWERS AND A FEW THUNDERSTORMS TODAY. CLOUDINESS SHOULD LIMIT
INSTABILITY. THE NAM INDICATES MAINLY WEAK INSTABILITY WITH LAPSE
RATES NEAR MOIST ADIABATIC. ANY THUNDERSTORMS SHOULD GENERALLY BE
NON-SEVERE. HOWEVER...THE WATER VAPOR IMAGERY INDICATES SOME MID-
LEVEL DRYING SHOULD OVERSPREAD THE AREA. THIS MAY LEAD TO BREAKS
IN THE OVERCAST WITH POSSIBLE STRONGER INSTABILITY AND THE DRY AIR
COULD AID DOWNDRAFTS. THEREFORE...SEVERE THUNDERSTORMS COULD
POSSIBLY OCCUR. THE TEMPERATURE GUIDANCE WAS CLOSE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SHORTWAVE ENERGY WILL BE LIFTING AWAY FROM THE FORECAST AREA THIS
EVENING AND MID LEVEL FLOW BECOMES MORE SOUTHWESTERLY RATHER THAN
SOUTHERLY. THIS WILL SHIFT THE AXIS OF DEEPER MOISTURE NORTHEAST
OF THE FORECAST AREA AS PRECIPITABLE WATER VALUES DECREASE THROUGH
THE OVERNIGHT HOURS TO JUST OVER AN INCH BY 12Z TUESDAY. WILL
CONTINUE WITH HIGH CHANCE POPS TO START THE PERIOD WITH CHANCES OF
RAIN DIMINISHING DURING THE OVERNIGHT HOURS AS THE ATMOSPHERE
DRIES AND BECOMES MORE STABLE.

THE FORECAST AREA FALLS BETWEEN SHORTWAVES ON TUESDAY AND DO NOT
EXPECT MUCH MORE THAN ISOLATED TO SCATTERED DIURNAL CONVECTION
AS THE ATMOSPHERE DESTABILIZES. TEMPERATURES SHOULD BE A BIT
WARMER WITH SOME BREAKS IN THE CLOUDS AND MAX TEMPERATURES ARE
EXPECTED IN THE LOWER TO MID 80S.

NORTHERN STREAM ENERGY TRACKING ACROSS THE GREAT LAKES REGION LATE
TUESDAY INTO WEDNESDAY WILL PICK UP THE LINGERING LOW PRESSURE
SYSTEM OVER THE TENNESSEE VALLEY AND PUSH THAT TROUGH EASTWARD
INTO THE FORECAST AREA ON WEDNESDAY. A SURFACE COLD FRONT WILL
ALSO PUSH EAST INTO THE AREA LATE WEDNESDAY. FORECAST SOUNDINGS
INDICATE MODERATE INSTABILITY ON WEDNESDAY AND THIS COMBINED WITH
AN APPROACHING SURFACE BOUNDARY WITH UPPER LEVEL SUPPORT IN THE
FORM OF A SHORTWAVE SHOULD YIELD AT LEAST SCATTERED
CONVECTION...SOME OF WHICH COULD BECOME STRONG. 500MB TEMPERATURES
COOL TO -14C WHICH WILL AID IN ATMOSPHERIC DESTABILIZATION. WILL
CARRY MID CHANCE POPS AT THIS TIME ALTHOUGH THIS MAY NEED TO BE
INCREASED WITH FUTURE UPDATES. MOISTURE IS THE LIMITING FACTOR AS
PRECIPITABLE WATER VALUES REMAIN BELOW 1.5 INCHES BUT THERE WILL
BE ENOUGH LOW LEVEL MOISTURE IN PLACE TO SUPPORT CONVECTION. MAX
TEMPERATURES ON WEDNESDAY WILL AGAIN BE IN THE 80-85 RANGE.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
MEDIUM RANGE MODELS HAVE COME INTO REASONABLE AGREEMENT WITH
POTENTIAL COASTAL LOW OFF THE CAROLINA COAST DURING THE EXTENDED
FORECAST PERIODS. BOTH GFS/ECMWF PUSH THE TROUGH FAR ENOUGH OFF
THE COAST THAT CONFIDENCE HAS INCREASED THAT THE SYSTEM LIKELY
WILL NOT AFFECT THE FORECAST AREA VERY MUCH. HIGH PRESSURE BUILDS
DOWN THE EAST COAST THURSDAY AND FRIDAY AS AN UPPER RIDGE BUILDS
OVER THE LOWER MISSISSIPPI VALLEY NORTHWARD INTO THE OHIO VALLEY
FOR THE WEEKEND. THIS WILL YIELD DRY WEATHER OVER OUR AREA THROUGH
THE WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED.

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...
AN H5 SHORTWAVE TROUGH...WEAK H85 WARM ADVECTION AND CONVERGENCE
AHEAD OF THE FRONT WILL SUPPORT NUMEROUS SHOWERS AND A FEW
THUNDERSTORMS TODAY. EXPECT IFR CONDITIONS THROUGH MUCH OF THE
MORNING. HEATING SHOULD BRING SOME IMPROVEMENT THIS AFTERNOON AND
EXPECT MAINLY VFR CEILINGS WILL DEVELOP...BUT THERE WILL BE
SCATTERED SHOWERS AND THUNDERSTORMS WITH IFR CONDITIONS. CONFIDENCE
IN THE TIMING OF HEAVIER SHOWERS AND THUNDERSTORMS WAS TOO LOW TO
INCLUDE IN THE TAFS AT THIS TIME.

EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR TO IFR CONDITIONS
POSSIBLE DURING THE REST OF TONIGHT THROUGH WEDNESDAY AS A LOW
PRESSURE SYSTEM SLOWLY CROSSES THE REGION.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$