National Weather Service Weather Forecast Office

Area Forecast Discussion

955
FXUS62 KCAE 230832
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
431 AM EDT THU MAY 23 2013

.SYNOPSIS...
AN APPROACHING COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
TONIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE DURING
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE AND INSTABILITY AHEAD OF A MID-LEVEL SHORTWAVE TROUGH
WAS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS EARLY THIS
MORNING. SATELLITE TRENDS AND THE MODELS INDICATE DEEPER MOISTURE
ASSOCIATED WITH THIS FEATURE WILL SHIFT EAST OF THE FORECAST AREA
LATER THIS MORNING. A PRE-FRONTAL TROUGH WILL BE IN THE FORECAST
AREA TODAY. CONVERGENCE ASSOCIATED WITH THIS FEATURE PLUS DIURNAL
HEATING SHOULD SUPPORT THUNDERSTORMS BUT EXPECT LIMITED COVERAGE
BECAUSE OF DIMINISHED MOISTURE BEHIND THE MID-LEVEL SHORTWAVE
TROUGH. MAINTAINED CHANCE POPS WITH THE GREATER VALUES IN THE
NORTHEAST PART CLOSER TO DEEPER MOISTURE AND MORE CONVERGENCE
ASSOCIATED WITH THE SURFACE TROUGH. MODERATE INSTABILITY MAY
SUPPORT DAMAGING WIND WITH A FEW OF THE THUNDERSTORMS. WET-BULB
ZERO HEIGHTS ALSO SUPPORT HAIL. THE TEMPERATURE GUIDANCE WAS
CLOSE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CONVERGENCE ASSOCIATED WITH THE COLD FRONT MAY SUPPORT
THUNDERSTORMS EARLY. COVERAGE SHOULD STILL BE LIMITED WITH DEEPER
MOISTURE EAST OF THE AREA. DRYING BEHIND THE FRONT SHOULD DOMINATE
LATE TONIGHT THROUGH FRIDAY NIGHT. MIXING ASSOCIATED WITH THE
FRONT SUPPORTED THE WARMER TEMPERATURE GUIDANCE TONIGHT. WE WILL
GET OFF TO A RELATIVELY WARM START SO THE WARMER GUIDANCE APPEARED
BETTER FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE
FRIDAY NIGHT.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. EXPECT SOME INCREASE IN MOISTURE BEGINNING MONDAY. THE
GFS AND ECMWF DISPLAY A WARM FRONT DEVELOPING NEAR THE AREA. THE
GFS IS FARTHER NORTHWARD WITH THE PLACEMENT OF THE FRONT. THE GFS
ALSO SHOWS LESS MOISTURE IN THE FORECAST AREA. BOTH MODELS SHOW
AN INCREASE IN H5 RIDGING WHICH SHOULD LIMIT THUNDERSTORMS.
BELIEVE THE BEST FORECAST FOR NOW IS AN AVERAGE OF THE GFS AND
ECMWF MOS. FORECASTED SLIGHT CHANCE POPS TUESDAY AND WEDNESDAY.

&&

.AVIATION /08Z THURSDAY THROUGH TUESDAY/...
CONVECTION CONTINUES TO SLOWLY WEAKEN AS IT MOVES TO THE ENE. MOST
ACTIVITY CURRENTLY CONFINED TO THE UPSTATE SC AND EASTERN GA. HIGH
RES MODELS CONTINUE TO SUGGEST THE ACTIVITY WILL GRADUALLY WEAKEN AS
IT MOVES INTO THE AREA. WILL MENTION A TEMPO GROUP FOR SHOWERS FOR
AGS/DNL UNTIL AROUND 09Z-10Z...AND 10Z-11Z AT CAE/CUB. NOT ENOUGH
CONFIDENCE TO MENTION PRECIP AT OGB AT THIS TIME.

GUIDANCE ALSO CONTINUING TO INDICATE CIG RESTRICTIONS EARLY THIS
MORNING...IN A CONTINUED MOIST SOUTHERLY LOW LEVEL FLOW. FOR
NOW...WILL INDICATE A PERIOD OF MVFR CIGS. WILL MONITOR LATEST
GUIDANCE FOR POSSIBLE ADJUSTMENT TO IFR IF NEEDED. UPPER IMPULSE AND
SURFACE TROUGH WILL MOVE THROUGH LATER TODAY...POSSIBLY LEADING TO
SCT SHRA/TSRA. DUE TO THE SCATTERED NATURE OF THE CONVECTION...WILL
NOT MENTION PRECIPITATION AT ANY OF THE TAF SITES FOR THE AFTERNOON
HOURS. BY LATE THIS EVENING...SKIES SHOULD BEGIN TO CLEAR AS DRIER
AIR MOVES INTO THE AREA FROM THE WEST.

EXTENDED AVIATION OUTLOOK...DRIER AIR MOVING IN BEHIND A FRONT WILL
PRECLUDE ANY IMPACTS TO AVIATION...OTHER THAN BREEZY CONDITIONS
POSSIBLE FRI/FRI NT.

&&

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

$$