000
FXUS62 KCAE 211151
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
751 AM EDT TUE MAY 21 2013

.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.

&&

.NEAR TERM /TODAY/...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL DOMINATE TODAY. A MOIST SOUTH FLOW IS ASSOCIATED WITH THIS
FEATURE. STRATUS AND FOG EXPECTED TO BURN OFF ACROSS CENTRAL AND
WESTERN AREAS LATER IN THE MORNING. A MID-LEVEL SHORTWAVE TROUGH
WILL SUPPORT SHOWERS AND THUNDERSTORMS IN THE EXTREME NORTHEAST
PART EARLY THIS MORNING. THE MOISTURE PLUS HEATING SHOULD SUPPORT
ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS MAINLY THIS
AFTERNOON. EXPECT THE GREATER THUNDERSTORM COVERAGE IN THE EAST
PART CLOSER TO THE TROPICAL PLUME OF MOISTURE SHOWN BY THE WATER
VAPOR IMAGERY. CONVERGENCE ASSOCIATED WITH THE SEA- BREEZE FRONT
SHOULD ALSO AID COVERAGE IN THE EAST PART LATER THIS AFTERNOON.
CLOUDINESS SHOULD LIMIT INSTABILITY. THE NAM GENERALLY INDICATES
WEAK TO MODERATE INSTABILITY AND WEAK SHEAR. THE THREAT OF SEVERE
THUNDERSTORMS APPEARS LOW AT THIS TIME. THE GUIDANCE CONSENSUS
SUPPORTS HIGHS IN THE MIDDLE 80S WHICH IS NEAR CLIMATOLOGY.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
THE HIGH OFF THE SOUTHEAST COAST WILL CONTINUE TO DOMINATE
THROUGH WEDNESDAY NIGHT. THE MODELS SHOW CONSIDERATE MOISTURE IN
THE SOUTHERLY FLOW ON THE BACKSIDE OF THE OFFSHORE HIGH. EXPECT
SCATTERED THUNDERSTORMS ESPECIALLY DURING THE TIME OF MAXIMUM
HEATING. THE GUIDANCE CONSENSUS SUPPORTS CHANCE POPS. ALSO USED
THE CONSENSUS FOR THE TEMPERATURE FORECAST.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
CONVERGENCE ASSOCIATED WITH THE SLOW MOVING COLD FRONT SUPPORTS
THUNDERSTORMS THURSDAY AND THURSDAY NIGHT BUT THE MODELS SHOW
DEEPER MOISTURE SHIFTING FARTHER EASTWARD AHEAD OF THE FRONT. THE
GFS ENSEMBLE MEAN PLUS OPERATIONAL GFS AND ECMWF MOS SUPPORT
CHANCE POPS. THE DRY AIR MASS BEHIND THE FRONT SHOULD DOMINATE
DURING THE REST OF THE MEDIUM-RANGE PERIOD.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
LOW CLOUDS HAVE DEVELOPED OVER MUCH OF THE AREA EARLY THIS MORNING.
CIGS MOSTLY IN THE IFR/LIFR RANGE...WITH LIFR VSBYS AT AGS. CAE VWP
INDICATING 20 KT LOW-LEVEL JET. FOG AND LOW STRATUS SHOULD DISSIPATE
BY 14Z WITH VFR CONDITIONS EXPECTED FOR THE REMAINDER OF THE PERIOD.
WINDS WILL PICK UP OUT OF THE SOUTH TO SOUTHEAST AROUND 5-7 KNOTS.
WIDELY SCTD CONVECTION POSSIBLE LATER THIS AFTERNOON BUT NOT ENOUGH
CONFIDENCE TO MENTION AT ANY OF THE TAF SITES AT THIS TIME. MODEL
DATA SEEMS TO INDICATE THAT BULK OF CONVECTION THAT MAY DEVELOP
LATER THIS AFTERNOON MAY BE EAST OF THE TAF SITES. SOME MVFR FOG MAY
DEVELOP EARLY WEDNESDAY MORNING TOWARDS THE END OF THE TAF PERIOD.

EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY AFTERNOON AND EVENING...POSSIBLE THROUGH
FRIDAY. LATE NIGHT/EARLY MORNING FOG/STRATUS ALSO POSSIBLE.

&&

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

$$