National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS62 KCAE 090007
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
707 PM EST SUN DEC 8 2013

.SYNOPSIS...
SURFACE WEDGE FLOW WILL CONTINUE THROUGH THE REMAINDER OF THE
WEEKEND AND INTO MONDAY...RESULTING IN INCREASING RAIN CHANCES AND
MUCH COOLER TEMPERATURES. ANOTHER COLD FRONT WILL SLOWLY MOVE
THROUGH LATE MONDAY AND TUESDAY...AND STALL JUST TO OUR SOUTH
WEDNESDAY. DRY HIGH PRESSURE IS EXPECTED TO RETURN THE MID TO LATE
WEEK...WITH ANOTHER SYSTEM ARRIVING NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WEDGE CONDITIONS WILL REMAIN OVER THE REGION TONIGHT KEEPING
OVERCAST SKIES AND DRIZZLE ACROSS THE FORECAST AREA. ALTHOUGH WSR-
88D INDICATES NO RETURNS SURFACE OBSERVATIONS SHOW SOME PATCHY
DRIZZLE ACROSS THE AREA. MAIN CONCERN OVERNIGHT WILL BE
POTENTIAL FOR FOG DEVELOPMENT AND DENSE FOG DURING THE EARLY
MORNING AND COMMUTE HOURS. FOR NOW WILL REMAIN WITH PATCHY FOG AND
MONITOR FOG DEVELOPMENT OVER THE NEXT COUPLE OF HOURS.
TEMPERATURES HAVE ALREADY FALLEN INTO THE MIDDLE 30S ALONG THE NC
LINE AND THE LOW 40S IN THE CSRA. WITH THE LOW CLOUDS AND FOG
EXPECT OVERNIGHT LOWS ONLY SLIGHTLY COOLER WITH SOME WARMING JUST
BEFORE SUNRISE.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
LATEST NAM/LOCAL MODEL WITH SUPPORT FROM SREF SUGGESTS WEDGE WILL
BE SLOWER TO BREAK DOWN DURING THE DAY MONDAY. CONFIDENCE LOW ON
TEMPERATURE FORECAST. ALTHOUGH STRONG SOUTH FLOW IN THE BOUNDARY
LAYER DEVELOPS DURING THE MORNING 30 TO 40 KTS...MODEL SOUNDINGS
INDICATE STRONG SURFACE BASED INVERSION AND LIGHT WINDS NEAR
SURFACE. WITH ANA-TYPE FRONT APPROACHING FROM THE
WEST...CONSIDERABLE CLOUDS...COOL START AND CHANCE RAIN...PREFER
SREF TEMPERATURE MEAN. SREF MEAN AT COLUMBIA IS AROUND 58. EXPECT
LARGE RANGE IN TEMPERATURES ACROSS REGION...WILL FORECAST LOW 50S
NORTH TO AROUND 70 CSRA/SOUTHEAST MIDLANDS. STRONGEST ISENTROPIC
LIFT ACROSS PIEDMONT/NORTH MIDLANDS...SO EXPECT HIGHER CHANCE RAIN
IN THAT REGION...LOWER CHANCE SOUTHEAST MIDLANDS/CSRA.

POPS INCREASE AGAIN TO LIKELY MONDAY NIGHT IN NORTH MIDLANDS AS
THE COLD FRONT PUSHES EAST INTO THE FORECAST AREA. POOLING
MOISTURE ON THE FRONT WITH PRECIPITABLE WATER VALUES RISING TO
AROUND 1.5 INCHES ALONG WITH INCREASED LOW LEVEL CONVERGENCE
SUPPORT HIGHER POPS. LOWER POPS IN THE SOUTHEAST MIDLANDS WHERE
FORCING WEAKER. UPPER FLOW BECOMES MORE ZONAL DURING THE AFTERNOON
WHICH SHOULD HELP PUSH THE FRONT EAST OF THE FORECAST AREA WITH
DRIER AIR WORKING IN FROM THE WEST BY TUESDAY EVENING AND POPS
WILL DECREASE SIGNIFICANTLY.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
12Z MODELS APPEAR DRIER ON WEDNESDAY BUT FRONT MAY STALL JUST
SOUTH OF THE FORECAST AREA WITH BROAD SOUTHWESTERLY FLOW ALOFT
AND THEREFORE WILL HOLD ON TO A SLIGHT CHANCE POP IN THE
SOUTHEASTERN MIDLANDS AND CSRA TO ACCOUNT FOR SOME OVERRUNNING
PRECIPITATION. BUT CUT PREVIOUS FORECAST POPS SLIGHTLY BASED ON
TREND. WILL KEEP DRY FORECAST WEDNESDAY NIGHT AND THURSDAY AS
PRECIPITABLE WATER VALUES FALL BELOW 0.5 INCHES.

SURFACE HIGH PRESSURE SETTLES OVER THE AREA THURSDAY AND FRIDAY
WITH BELOW NORMAL TEMPERATURES EXPECTED TO END THE WEEK INTO THE
WEEKEND. GFS MODEL SUGGESTS ANOTHER WET WEEKEND MAY BE IN STORE AS
AMPLIFYING UPPER FLOW DROPS A TROUGH INTO THE SOUTHERN PLAINS AND
SURFACE LOW PRESSURE DEVELOPS ALONG THE GULF COAST STATES AND
MOVES ACROSS THE SOUTHEAST ON SATURDAY. THE ECMWF HOLDS BACK THE
ENERGY IN THE DESERT SOUTHWEST AND THEREFORE IS SLOWER WITH THE
TIMING OF THIS FEATURE. GIVEN THE DIFFERENCES AMONG THE MODELS AT
THAT TIME RANGE WILL OPT TO CARRY ONLY CHANCE POPS FOR NOW.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
STRONG WEDGE CONDITIONS CONTINUE ACROSS THE AREA EARLY THIS
EVENING WITH NORTHEAST WINDS AROUND 5 KTS. ALL TAF SITES
CURRENTLY IFR DUE TO CEILINGS AND SOME LIGHT FOG AND DRIZZLE.
MODEL TIME SECTIONS CONTINUE TO SHOW ABUNDANT LOW LEVEL MOISTURE
THROUGH THE TAF PERIOD. DEEPEST ISENTROPIC LIFT HAS SHIFTED TO THE
UPSTATE...BUT PLENTY OF LOW LEVEL ISENTROPIC LIFT TO PRODUCE AREAS
OF DRIZZLE ACROSS THE CWA THIS EVENING AND THROUGH MUCH OF THE OF
THE TAF PERIOD. GUIDANCE HAS CONDITIONS LOWERING TO LIFR AT ALL
TAF SITES BY LATER THIS EVENING. HAVE TRENDED TAFS DOWNWARD
THROUGH THE PERIOD WITH LOWEST CONDITIONS LATE TONIGHT INTO EARLY
MONDAY. MODELS STILL TRY TO HOLD ON TO THE WEDGE THROUGH MONDAY
MORNING THROUGH MIDDAY. WILL KEEP LOW CONDITIONS IFR/LIFR FOR MUCH
OF THE PERIOD...BECOMING MVFR BY THE AFTERNOON.

EXTENDED AVIATION OUTLOOK..GRADUAL IMPROVEMENT IS EXPECTED LATE
MONDAY INTO TUESDAY AHEAD OF A FRONT THAT WILL SLOWLY MOVE THROUGH.
THERE WILL BE A CHANCE OF SHOWERS AND ASSOCIATED RESTRICTIONS WITH
THE FRONT. THE FRONT IS FORECAST TO STALL JUST TO OUR SOUTH
WEDNESDAY WITH HIGH PRESSURE BUILDING EASTWARD TO OUR NORTH. A
RETURN TO VFR CONDITIONS POSSIBLE WEDNESDAY...BUT CONFIDENCE IS
LOW. BY THURSDAY...HIGH PRESSURE BEGINS TO DOMINATE THE AREA AND
VFR CONDITIONS ARE MORE CONFIDENT.

&&

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

$$