FXUS62 KCAE 101725
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1222 PM EST THU DEC 10 2009
.SYNOPSIS...
DRY HIGH PRESSURE WILL DOMINATE THROUGH FRIDAY. A LOW PRESSURE
SYSTEM FROM THE GULF OF MEXICO MAY BRING RAIN SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 9 AM...THE COLD FRONT WAS OFF THE COAST WITH LINGER TROUGH OF
LOW PRESSURE LEE OF THE APPALACHIANS. HIGH PRESSURE OVER OK/AR TO
BUILD EASTWARD THIS AFTERNOON. BAND OF HIGH/MID LEVEL CLOUDS OVER
THE EASTERN MIDLANDS AND SRN SAVANNAH RIVER AREA WILL BE MOVE OUT
BY MIDDAY. EXPECTING STRONG COLD AIR ADVECTION. WEST WINDS
BECOMING MORE NORTHWEST. DOWN SLOPE FLOW TO DRY OUT AIR MASS. HAVE
LOWER DEWPOINTS A BIT FOR THE AFTERNOON. WIND GUSTS 20-25 KNOTS.
HIGHS IN THE LOW TO MID 50S STILL LOOK REASONABLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THE DRY RIDGE SHOULD REMAIN IN CONTROL THROUGH FRIDAY. EXPECT
UPPER-LEVEL CLOUDINESS WILL BE MAINLY THIN TONIGHT SO THERE SHOULD
BE STRONG RADIATIONAL COOLING. THE GUIDANCE IS CONSISTENT WITH LOWS
IN THE MIDDLE TO UPPER 20S. THE NAM AND GFS KEEP DEEP MOISTURE
SUPPRESSED SOUTH OF THE FORECAST AREA THROUGH FRIDAY NIGHT. THE
MODELS SHOW JUST WEAK ISENTROPIC LIFT IN THE SOUTH PART FRIDAY NIGHT.
THE WEAK LIFT AND INITIAL DRYNESS SUPPORT THE MOS POPS OF LESS
THAN 20 PERCENT...BUT FOR FORECAST CONSISTENCY AND THE TIGHT
MOISTURE GRADIENT DID KEEP A SLIGHT CHANCE OF LIGHT RAIN IN THE
EXTREME SOUTH PART FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE ECMWF IS SLOWER SPREADING MOISTURE NORTHWARD INTO THE FORECAST
AREA SATURDAY COMPARED TO THE GFS. THE GFS TREND HAS BEEN SLOWER.
PLAN TO LOWER POPS SLIGHTLY SATURDAY...BUT STILL WILL HAVE CHANCE
POPS IN THE NORTH TO LIKELY IN THE SOUTH. THE DRY AIR MASS IN PLACE
AND EVAPORATIVE COOLING POTENTIAL SUPPORTS POSSIBLE SLEET...BUT THE
CHANCE APPEARS LOW BECAUSE OF THE DELAYED TIMING. LOW PRESSURE
REMAINING NEAR THE COAST SUPPORTS A CONTINUED RAIN CHANCE SUNDAY.
THE GFS SHOWS BRIEF DRYING FOR MONDAY...BUT A RETURN TO HIGH
MOISTURE TUESDAY ASSOCIATED WITH A COLD FRONT.
&&
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
VFR CIGS/VSBY THROUGH THE TAF PERIOD. EXPECT HIGH LEVEL CLOUDS TO
INCREASE ACROSS THE TAF SITES OVERNIGHT. WEST TO NORTHWEST WINDS 10
TO 15 KT WITH GUSTS AROUND 20 KT THIS AFTERNOON. WINDS WILL
DIMINISH TO AROUND 5 KT AFTER 00Z FRIDAY. WINDS BECOMING VARIABLE
AROUND 5 KT DURING THE DAY FRIDAY AS HIGH PRESSURE MOVES CLOSER TO
THE AREA.
EXTENDED AVIATION OUTLOOK...CIGS AND VSBYS RESTRICTIONS ARE FORECAST
FOR SATURDAY INTO SUNDAY AS GULF COAST STORM SYSTEM SPREADS RAIN
INTO THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AVIATION...10
