FXUS62 KCAE 040527
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1227 AM EST FRI DEC 4 2009
.SYNOPSIS...
HIGH PRESSURE WILL TEMPORARILY BUILD INTO EARLY FRIDAY. AN AREA
OF LOW PRESSURE WILL FORM TO OUR SOUTH LATE FRIDAY AND MOVE
NORTHEAST SATURDAY... SPREADING RAIN NORTHWARD INTO OUR REGION.
FAIR WEATHER EXPECTED SUNDAY AND MONDAY. MOISTURE RETURN BY THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SKIES HAVE CLEARED THIS EVENING AS HIGH PRESSURE CONTINUES TO
BUILD INTO THE REGION. SOME HIGH CLOUDS WILL BE MOVING IN FROM THE
SOUTH LATE TONIGHT BUT SHOULD NOT HAVE TOO MUCH OF AN IMPACT ON
OVERNIGHT LOWS AS THEY ARRIVE LATE AND WILL REMAIN THIN. CURRENT
FORECAST OF LOWS IN THE UPPER 30S TO AROUND 40 LOOKS ON TRACK AS
HOURLY TEMPERATURES ALSO IN LINE...SO NO CHANGES NEEDED. WILL
UPDATE FORECAST TO IMPROVE SKY CONDITION TO MOSTLY CLEAR
OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
CLOUDS WILL SLOWLY INCREASE DURING THE DAY FRIDAY WITH MAX TEMPS
PUSHING INTO THE UPPER 50S TO AROUND 60 DEGREES WITH HIGH
PRESSURE TO OUR NORTH AND WEST. BY LATE FRIDAY...A STRONG UPPER
IMPULSE LOCATED NEAR THE INTERMOUNTAIN REGION WILL SWING AROUND
THE BASE OF THE BROAD UPPER TROUGH...INDUCING WEAK SFC LOW
DEVELOPMENT ON THE COLD FRONT NOW LOCATED WELL OFF THE CAROLINA
COAST. MODELS SEEM TO BE IN GENERAL OVERALL GOOD AGREEMENT WITH
TIMING OF SYSTEM. PRECIPITATION SHOULD BEGIN TO DEVELOP FROM SOUTH
TO NORTH BY FRIDAY NIGHT...AND CONTINUING WELL INTO SATURDAY.
PRECIPITATION TYPE DOES NOT APPEAR TO BE AN ISSUE WITH THIS SYSTEM
AS PARAMETERS POINT TO ALL RAIN. HAVE INCREASED POPS TO
CATEGORICAL FRIDAY NIGHT ESPECIALLY FOR THE SOUTHERN COUNTIES AS
PER MODEL CONSENSUS. LOW PRESSURE WILL QUICKLY MOVE OFF TO THE
NORTHEAST BY LATE SATURDAY SO RAIN WILL COME TO AN END DURING THE
EVENING HOURS. AFTERNOON TEMPS SATURDAY WILL STRUGGLE TO REACH THE
LOW TO MID 40S WITH WEAK LOW-LEVEL CAA AND CLOUD COVER. SKIES WILL
SLOWLY CLEAR LATE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BUILD OVER THE EASTERN SEABOARD SUNDAY INTO
MONDAY. CLOUDS WILL INCREASE MONDAY AHEAD OF A WEAK UPPER LEVEL
IMPULSE BUT DO NOT EXPECT ANY PRECIPITATION. NEXT CHANCE FOR RAIN
WILL BE WEDNESDAY INTO THURSDAY AHEAD OF ANOTHER DEVELOPING
FRONTAL SYSTEM APPROACHING FROM THE WEST. TEMPS CLOSE TO MODEL
CONSENSUS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
DRYING HAS OCCURRED BEHIND A COLD FRONT. EXPECT MAINLY VFR
CONDITIONS. THE MAIN FORECAST PROBLEM IS THE FOG POTENTIAL. HIGH
SOIL MOISTURE AND CROSS-OVER TEMPERATURES SUPPORT EARLY MORNING FOG.
HOWEVER...THE MODELS SHOW A LITTLE MIXING AND MAINTAIN TEMPERATURE
DEW POINT TEMPERATURE SPREADS. KEPT A VFR FORECAST...EXCEPT
FORECASTED A PERIOD OF MVFR FOG AT OGB BECAUSE OF THE ADDED
MOISTURE ASSOCIATED WITH THE RIVER VALLEY AND A SLIGHTLY LESS
PRESSURE GRADIENT INDICATING A LITTLE LESS MIXING. THIS WAS
SUPPORTED BY THE GFS LAMP GUIDANCE. ISENTROPIC LIFT AND MOISTURE
WILL BE ON THE INCREASE LATE IN THE TAF PERIOD WITH LOWERING
CEILINGS.
EXTENDED OUTLOOK...LOW PRESSURE MOVING INTO THE REGION WILL LIKELY
BRING WIDESPREAD MVFR OR LOWER CONDITIONS LATE FRIDAY NIGHT AND
SATURDAY.
DRYING HAS OCCURRED BEHIND A COLD FRONT. EXPECT MAINLY VFR
CONDITIONS. THE MAIN FORECAST PROBLEM IS THE FOG POTENTIAL. HIGH
SOIL MOISTURE AND CROSS-OVER TEMPERATURES SUPPORT EARLY MORNING FOG.
HOWEVER...THE MODELS SHOW A LITTLE MIXING AND MAINTAIN
TEMPERATURE-DEW POINT TEMPERATURE SPREADS. KEPT A VFR
FORECAST...EXCEPT FORECASTED A PERIOD OF MVFR FOG AT OGB BECAUSE OF
THE ADDED MOISTURE ASSOCIATED WITH THE RIVER VALLEY AND A SLIGHTLY
WEAKER PRESSURE GRADIENT INDICATING A LITTLE LESS MIXING. THIS
WAS SUPPORTED BY THE GFS LAMP GUIDANCE.
EXTENDED OUTLOOK...ANOTHER LOW PRESSURE SYSTEM IS EXPECTED TO BRING
WIDESPREAD MVFR OR LOWER CONDITIONS FRIDAY NIGHT AND SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...07
