FXUS62 KCAE 091801
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
101 PM EST WED DEC 9 2009
.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TODAY. WINDY
CONDITIONS WILL BE ASSOCIATED WITH THIS FRONT. DRY HIGH PRESSURE
BEHIND THE FRONT WILL DOMINATE TONIGHT THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
THE LAST OF THE SHOWERS ARE MOVING EAST OF THE MIDLANDS LATE THIS
MORNING. ALTHOUGH THERE IS SOME CLEARING OF CLOUDS FROM THE WEST, WILL
CONTINUE WITH PARTLY SUNNY FOR THE AFTERNOON UNTIL DRIER AIR
BEGINS TO MOVE IN. STILL EXPECT WINDS TO INCREASE FOR THE AFTERNOON.
THE NAM INDICATES GUSTS OF 35 TO 40 KNOTS MAY MIX TO THE SURFACE
WHICH IS NEAR THE WIND ADVISORY CRITERIA. THE WIND PLUS SATURATED
SOIL MAY RESULT IN A FEW DOWNED TREES. THE WIND ADVISORY WILL
CONTINUE IN EFFECT UNTIL UNTIL 6 PM.
TEMPERATURES ALREADY IN THE MID 60S SOUTH TO MID 50S NORTH. KEPT
AFTERNOON HIGHS IN THE UPPER 60S TO MID 70S.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DRY HIGH PRESSURE BEHIND THE COLD FRONT SHOULD DOMINATE TONIGHT
THROUGH THURSDAY NIGHT. LIGHT WIND AND STRONG RADIATIONAL COOLING
SUPPORTS COLD TEMPERATURES THURSDAY NIGHT. THE NAM AND GFS MOS SHOW
LOWS IN THE MID TO UPPER 20S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE DRY RIDGE SHOULD CONTINUE TO DOMINATE FRIDAY. THE GFS SHOWS WEAK
ISENTROPIC LIFT AND INCREASING MOISTURE IN THE SOUTH PART FRIDAY
NIGHT. BASED ON THE DRY AIR MASS THAT SHOULD BE IN PLACE AT THE TIME
AND THE EVAPORATIVE COOLING POTENTIAL THERE WILL BE A POSSIBILITY OF
SLEET. HOWEVER...THE ECMWF KEEPS DEEPER MOISTURE SUPPRESSED FARTHER
SOUTH AND KEEPS THE ENTIRE FORECAST AREA DRY THROUGH FRIDAY NIGHT.
THE GFS ENSEMBLES SHOW HIGH SPREAD. BASED ON THE UNCERTAINTY AND
MARGINAL TEMPERATURES BELIEVE THE BEST FORECAST FOR NOW IS A SMALL
CHANCE OF RAIN IN THE SOUTH PART FRIDAY NIGHT. THE GFS SHOWS THE
MOISTURE SPREADING FARTHER NORTHWARD SATURDAY. THE ECMWF STILL APPEARS
TOO KEEP DEEPER MOISTURE SUPPRESSED FARTHER SOUTH. PLAN TO FORECAST
A CHANCE OF PRECIPITATION AREA-WIDE SATURDAY. BASED ON THE EVAPORATIVE
COOLING POTENTIAL AT THE START OF THE EVENT...SLEET APPEARS
POSSIBLE MAINLY IN THE NORTH PART. UNCERTAINTY REMAINS HIGH DURING
THE REST OF THE PERIOD. THE GFS SHOWS DRYING MONDAY...BUT A QUICK
RETURN OF MOISTURE FOR TUESDAY. THE GFS ENSEMBLES CONTINUE TO
INDICATE HIGH SPREAD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SW WINDS EXPECTED TO INCREASE THIS AFTERNOON WITH GOOD PRESSURE
GRADIENT AND DAYTIME HEATING. WIND SPEED 20 TO 25 KTS WITH GUSTS
FROM 30 TO 35 KTS POSSIBLE AT TAF SITES THROUGH THE AFTERNOON. WINDS
WILL GRADUALLY DIMINISH THIS EVENING INTO THE OVERNIGHT HOURS. MODEL
TIME SECTIONS INDICATE THAT SOME MID/HIGH LEVEL CLOUDS WILL MOVE
ACRS THE AREA OVERNIGHT. HIGH PRESSURE WILL CONTINUE TO BUILD IN
FROM THE WEST ON THU WITH WINDS LESS THAN 10 KTS...VFR CONDITIONS
CONTINUE.
EXTENDED AVIATION OUTLOOK...ANOTHER SYSTEM WILL BE
APPROACHING/EFFECT THE AREA FRIDAY NIGHT/SAT WITH POSSIBLE IFR
CEILINGS/VSBYS FOR FRIDAY NIGHT/SAT.
S
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR SCZ015-016-018-
020>022-025>031-035>038-041.
GA...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR GAZ040-063>065-
077.
&&
$$
