000
FXUS62 KCAE 212251
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
651 PM 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 /UNTIL 6 AM WEDNESDAY MORNING/...
SATELLITE AND RADAR TRENDS AT 2145Z INDICATE SCATTERED THUNDERSTORM
FOCUS NOW IN THE CSRA EARLY THIS EVENING. POPS DECREASING TO THE
NORTH ACROSS THE MIDLANDS. THUNDERSTORMS SHOULD DIMINISH DURING
THE NEXT COUPLE OF HOURS.

LOWS WILL FALL INTO THE MIDDLE 60S.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY AND WEDNESDAY NIGHT...LOW PRESSURE WILL CONTINUE MOVING
THROUGH THE CENTRAL GREAT LAKES WITH HIGH PRESSURE OFF THE MID
ATLANTIC COAST. THIS WILL CONTINUE THE SOUTHERLY WINDS AND
MOISTURE ADVECTION INTO THE AREA ALONG WITH INSTABILITY. RESULT
WILL BE ANOTHER ROUND OF AFTERNOON AND EVENING CONVECTION WITH THE
GREATEST POTENTIAL ACROSS THE EASTERN MIDLANDS. WITH PWAT VALUES
REMAINING IN THE 1.6 TO 1.7 INCH RANGE THE POSSIBILITY OF HEAVY
RAINFALL WILL BE THE MAIN THREAT CAUSING STANDING WATER IN LOW
LYING AND POOR DRAINAGE AREAS. WITH THE UPPER TROUGH MOVING AWAY
FROM THE AREA AND UPPER HEIGHTS RISING SLIGHTLY TEMPERATURES WILL
BE SLIGHTLY HIGHER WITH MID 80S FOR MOST LOCATIONS. CONVECTION
WILL DIMINISH WITH SUNSET...HOWEVER WITH THE COLD FRONT
APPROACHING FROM THE WEST THERE IS SOME POTENTIAL FOR SHOWERS AND
THUNDERSTORMS WEDNESDAY NIGHT MAINLY OVER THE WESTERN MIDLANDS.
OVERNIGHT LOWS WILL GENERALLY BE IN THE MID 60S.

THURSDAY AND THURSDAY NIGHT...THURSDAY WILL SEE ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS AS THE COLD FRONT CROSSES THE REGION.
ALTHOUGH MODELS DIFFER SLIGHTLY ON TIMING OF FROPA INDICATIONS ARE
FOR LATE MORNING TO EARLY AFTERNOON. THIS WILL ALLOW THE BEST
HEATING OVER THE EASTERN MIDLANDS ALONG WITH THE BEST CHANCE OF
CONVECTION. PWAT VALUES WILL AGAIN BE IN EXCESS OF 1.6 INCHES
CONTINUING THE THREAT FOR HEAVY RAIN. THE FRONT WILL MOVE OFFSHORE
DURING THE AFTERNOON HOURS WITH THE CHANCES OF SHOWERS DIMINISHING
RAPIDLY THROUGH THE EVENING HOURS AS DRIER AIR BEGINS TO PUSH INTO
THE FORECAST AREA. DAYTIME HIGHS WILL BE IN THE MID 80S WITH
OVERNIGHT LOWS IN THE MID 60S.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME
LOCATION DIFFERENCES APPEARING FOR SUNDAY INTO TUESDAY. PATTERN
WILL REMAIN ACTIVE AS HIGH PRESSURE AND DRIER AIR MOVE INTO THE
AREA ON FRIDAY AND FRIDAY NIGHT. ON SATURDAY AFTERNOON THE HIGH
WILL SLIDE SO THE SOUTHEAST AS THE NEXT LOW PRESSURE SYSTEM SLOWLY
TRIES TO DEVELOP OVER THE CENTRAL US. THIS WILL PUSH A FRONTAL
BOUNDARY TOWARD THE REGION ON SUNDAY...WITH THE GFS KEEPING THE
FRONT FURTHER NORTH AND THE ECMWF HAVING THE FRONT ALONG THE NC/SC
BORDER. BY MONDAY THE GFS HAS PUSHED THE FRONT INTO SOUTHERN NC
WITH THE ECMWF OVER THE NORTHERN MIDLANDS. HAVE GONE WITH A
COMPROMISE OF THE ECMWF AND GFS FOR THE LATTER HALF OF THE LONG
TERM WHICH CURRENTLY KEEPS THE AREA RAIN FREE THROUGH THE END OF
THE LONG TERM...HOWEVER CONFIDENCE IS LOW FOR SUNDAY THROUGH
TUESDAY. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
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.
&&

$$
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