Area Forecast Discussion Issued by NWS Columbia, SC
000
FXUS62 KCAE 222126
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST
SOUTHERLY FLOW INTO THE FORECAST AREA AHEAD OF A SLOW MOVING COLD
FRONT THROUGH THURSDAY. THE COLD FRONT WILL MOVE THROUGH THE AREA
THURSDAY NIGHT. THE DRY AIR MASS BEHIND THE FRONT WILL DOMINATE
DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
LESS MOISTURE THIS AFTERNOON THAN YESTERDAY...AND RESULTING
INSTABILITY WEAKER. SHOWERS ALONG SEA BREEZE FRONT WEAKENING AS
THEY MOVE INTO MIDLANDS. STRONGER CONVECTION IN NORTH
GEORGIA/UPSTATE BUT LITTLE MOVEMENT INTO MIDLANDS. WILL CUT POPS
BACK FROM PREVIOUS FORECAST...SLIGHT CHANCE REST OF AFTERNOON AND EVENING.
SKIES WILL BECOME MOSTLY CLOUDY TONIGHT AS THE FRONT APPROACHES
FROM THE WEST WITH CHANCES OF SHOWERS INCREASING FROM WEST TO EAST
DURING THE PRE-DAWN HOURS. OVERNIGHT LOWS WILL GENERALLY BE IN THE
MID 60S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSING THE EASTERN CONUS DURING THE
SHORT TERM. THE AIR MASS WILL BE UNSTABLE WITH A PRE-FRONTAL TROUGH
OVER THE MIDLANDS. LOW LEVEL MOISTURE LINGERS WITH PRECIPITABLE
WATER RANGING FROM 1.00 T0 1.75 INCHES. THE THREAT OF CONVECTION
WILL CONTINUE WITH THE HIGHEST CHANCE ACROSS THE MIDLANDS. WILL
RANGE POPS FROM NEAR 30 PERCENT CSRA TO 60 PERCENT NORTHEAST ON
THURSDAY. ALTHOUGH THE GFS IS SLIGHTLY FASTER...MODELS INDICATE THE
COLD FRONT CROSSING THE AREA THURSDAY NIGHT WITH THE CHANCE OF
CONVECTION ENDING.
THE TEMPERATURE GUIDANCE WAS CLOSE WITH HIGHS IN THE MID/UPPER 80S
AND LOWS IN THE LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE DRY AIR MASS BEHIND THE COLD FRONT SHOULD DOMINATE DURING THE
WEEKEND. THE GFS AND ECMWF INDICATED A WARM FRONT DEVELOPING
MONDAY WITH MUCH OF THE MOISTURE NORTH OF THE FORECAST AREA MONDAY
THROUGH WEDNESDAY. GFS ENSEMBLE INCREASE POPS SLIGHTLY THROUGH THE
MIDDLE OF NEXT WEEK. WILL KEEP THE FORECAST DRY GIVEN INCREASING
H500 HEIGHTS AS THE UPPER RIDGE BUILDS.
EXPECT BELOW NORMAL TEMPERATURES DURING THE WEEKEND AND NEAR NORMAL
DURING THE REST OF THE MEDIUM RANGE PERIOD.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
CURRENT MESOANALYSIS INDICATES GENERALLY MODERATE INSTABILITY OVER
THE REGION. SCATTERED SHOWERS AND A FEW THUNDERSTORMS CURRENTLY
ALONG A SEA BREEZE...BUT COVERAGE HAS BEEN DECREASING IN THE LAST
HOUR OR SO. OTHER CONVECTIVE ACTIVITY OVER THE UPSTATE AND PORTIONS
OF N/NE GA...MOVING SLOWLY. WILL EXPECT ACTIVITY TO GRADUALLY
DISSIPATE AND NOT AFFECT TERMINALS. OBS INDICATE MAINLY SCT CU
WITH BASES ABOVE VFR. HIGH RES MODELS INDICATE MORE SIGNIFICANT
ACTIVITY DEVELOPING TO OUR WEST NEAR AN UPPER IMPULSE AND SURFACE
TROUGH...WEAKENING AS IT APPROACHES THE FA LATE TONIGHT. GUIDANCE
INDICATING CIG RESTRICTIONS LATE TONIGHT...IN A CONTINUED MOIST
SOUTHERLY LOW LEVEL FLOW. UPPER IMPULSE AND SURFACE TROUGH WILL
MOVE THROUGH THURSDAY...POSSIBLY LEADING TO SCT SHRA/TSRA...BUT
CHANCES TOO LOW...ALONG WITH SOME TIMING QUESTIONS...TO INCLUDE
MENTION IN THE TAF AT THIS TIME.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE FRIDAY.
OTHERWISE...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$