286
FXUS62 KCAE 180619
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
119 AM EST THU DEC 18 2025
SYNOPSIS
WIDESPREAD SHOWERS ARE EXPECTED TODAY AS A COLD FRONT MOVES
THROUGH, ALONG WITH SOME GUSTY WINDS WHICH WILL INTO FRIDAY.
DRIER WEATHER AND A STEADY WARMING PATTERN IS THEN EXPECTED INTO
THE WEEKEND AND THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- CLOUDS AND SHOWERS ARE EXPECTED THROUGHOUT THE DAY TODAY.
- PRECIPITATION GENERALLY EXPECTED THROUGH MIDNIGHT, WITH DRIER
CONDITIONS AND INCREASINGLY GUSTY WINDS EXPECTED THEREAFTER.
WIDESPREAD HIGH CLOUDS ARE STREAMING ACROSS THE AREA FROM THE WEST
AND SOUTHWEST AS ATMOSPHERIC MOISTURE INCREASES AHEAD OF OUR NEXT
WEATHER MAKER. SURFACE HIGH PRESSURE CONTINUES TO DRIFT EASTWARD IN
ADVANCE OF THIS, WITH OUR FIRST SURGE IN MOISTURE FORECAST OVER THE
NEXT SEVERAL HOURS. THIS IS FORECAST TO LIFT NORTHWARD WITH
ISENTROPIC LIFT INCREASING ON THE WESTERN SIDE OF THE AFOREMENTIONED
HIGH. STRATOCUMULUS IS FORECAST TO DEVELOP WITHIN THIS MOISTURE
ADVECTION REGIME, WITH GUIDANCE CONSISTENTLY SHOWING SCATTERED
SHOWERS DEVELOPING AS WELL. THIS LOOKS TO BE PRIMARILY DRIVEN BY PW
ADVECTION, WITH VALUES RISING QUICKLY INTO THE LOW 1" RANGES BY 15Z.
MOISTURE STILL REMAINS LIMITED AT THE MOMENT, WHICH CASTS SOME DOUBT
ON HOW LOW THE CLOUDS WILL GET. BUT IT DOES LOOK LIKE DENSE CLOUDS
WILL INCREASE BY SUNRISE, OVERSPREADING THE FULL AREA BY LATE
MORNING INTO EARLY AFTERNOON. THE INITIAL SHOWERS SHOULD SHIFT TO
OUR NORTH WHERE ISENTROPIC LIFT WILL BE MAXIMIZED BY LATE MORNING.
AS WE GET INTO THIS AFTERNOON, A SOUTHERN STREAM, 500 HPA SHORTWAVE
IS FORECAST TO APPROACH FROM THE SOUTHWEST AND BE THE DRIVING FORCE
FOR WIDESPREAD SHOWERS DURING THE AFTERNOON AND EVENING HOURS. THIS
FEATURE IS FORECAST TO QUICKLY LIFT NORTHEASTWARD AS IT BEGINS
INTERACTING WITH A SHARP, ROBUST TROUGH EMERGING OUT OF THE NORTHERN
PLAINS. THE INITIAL SHORTWAVE WILL BE THE DRIVING FORCE FOR OUR
SHOWER ACTIVITY THIS AFTERNOON, WITH A BRIEF LULL FORECAST BY
GUIDANCE BETWEEN THE TWO WAVES OF PRECIPITATION. BUT IN
GENERAL, WIDESPREAD SHOWERS ARE EXPECTED TO DEVELOP/REDEVELOP
BETWEEN 1P AND 4P THIS AFTERNOON AND HANG AROUND THROUGH MUCH OF
THE EVENING. INSTABILITY IS LIMITED THROUGHOUT THE EVENT SO
THUNDERSTORMS AREN'T EXPECTED. RAINFALL MAY BE MODERATE AT
TIMES, HOWEVER, AS REFS/HREF GUIDANCE SUGGESTS THAT PWS NEAR THE
90TH PERCENTILE FOR DECEMBER (1.25"-1.5") LOOK TO OVERSPREAD
THE AREA IN ADVANCE OF THIS TROUGH. HIGHS ARE FORECAST TO BE
MUTED TODAY IN RESPONSE TO THE CLOUD COVER AND RAINFALL AND
SHOULD ONLY MAKE IT TO THE UPPER 50S OR LOW 60S FOR MOST, AND
THIS MAY BE A STRETCH DEPENDING ON HOW LOW/THICK THE CLOUDS ARE
AND IF WE GET ANY CLEARING AROUND MIDDAY.
BY TONIGHT, GUIDANCE GENERALLY SHIFTS THE PRECIPITATION EASTWARD.
THE INITIAL SHORTWAVE IS FORECAST TO SHIFT OFF TO THE EAST, WITH
UNFAVORABLE SYNOPTIC SCALE FORCING FOR PRECIPITATION REMAINING OVER
THE AREA. MID/UPPER LEVEL CONVERGENCE IS FORECAST TO INCREASE BY THE
MIDDLE OF THE NIGHT, ALONG WITH DRIER AIR SHIFTING INTO THE AREA.
THE LAST CHANCE OF RAIN IS FORECAST ALONG THE COLD FRONT AS IT
SHIFTS EASTWARD INTO THE AREA EARLY ON FRIDAY MORNING. WINDS
ARE FORECAST TO BEGIN PICKING UP LATE TONIGHT AS THE PRESSURE
GRADIENT INCREASES BEHIND THE FRONT, WITH WINDS GUSTING 20+ MPH
BY TOMORROW MORNING. LOOK FOR LOWS IN THE UPPER 40S TO MID 50S
ACROSS THE AREA.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
KEY MESSAGE(S):
- SLIGHTLY COOLER FOR THE SHORT TERM PERIOD.
- BREEZY CONDITIONS FRIDAY MORNING INTO AFTERNOON.
AT THE START OF THE SHORT TERM PERIOD, THE FRONT FROM
THURSDAY/THURSDAY NIGHT IS FORECAST TO BE JUST EAST OF THE FORECAST
AREA. HIGH PRESSURE IS ALSO EXPECTED TO BE BUILDING TO OUR WEST. AS
A RESULT, RAIN SHOULD BE OUT OF THE AREA FRIDAY MORNING. MEANWHILE,
BREEZY WINDS CAN BE EXPECTED AS THE PRESSURE GRADIENT BETWEEN THE
EXITING FRONT AND BUILDING HIGH REMAINS FAIRLY TIGHT. THE FRONT
CONTINUES MOVING EASTWARD THROUGH THE DAY, EASING THAT PRESSURE
GRADIENT AND ASSOCIATED WINDS. FLOW ALOFT IS EXPECTED TO BECOME MORE
ZONAL AS WE MOVE THROUGH THE SHORT TERM PERIOD AS THE UPPER TROUGH
ASSOCIATED WITH THE COLD FRONT SHIFTS NORTHEASTWARD. WHILE TEMPS ARE
FORECAST TO BE SLIGHTLY COOLER DURING THE DAY, THEY AREN'T EXPECTED
TO BE MUCH COOLER THAN AVERAGE, IF AT ALL. OVERNIGHT LOWS ARE
FORECAST TO BE CHILLY FRIDAY NIGHT, AROUND THE FREEZING MARK, BEFORE
REBOUNDING FOR SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
KEY MESSAGE(S):
- DRY WITH VARYING TEMPS THROUGH THE LONG TERM.
SURFACE HIGH IS EXPECTED TO SHIFT OFFSHORE ON SUNDAY, ALLOWING FOR
SOUTHWESTERLY FLOW TO BRING WARMER TEMPS BACK TO THE REGION. THERE
IS A HIGH CHANCE (>60%) CHANCE WE'LL SEE ABOVE AVERAGE TEMPS FOR
HIGHS. HOWEVER, IT WILL DEPEND ON WHEN THE NEXT COLD, BUT DRY FRONT
MOVES INTO THE REGION. MONDAY IS LOOKING SEVERAL DEGREES COOLER
AGAIN AFTER THE COLD FRONT MOVES THROUGH. DRY CONDITIONS CONTINUING
WITH A WARMING TREND ARE THEN EXPECTED AS AN UPPER RIDGE IS FORECAST
TO BUILD OVER THE REGION.
AVIATION /06Z THURSDAY THROUGH MONDAY/
VFR IN THE IMMEDIATE TERM, WITH RESTRICTIONS EXPECTED PERIODICALLY
THROUGHOUT THE PERIOD.
THE AIRMASS REMAINS DRY ACROSS THE AREA CURRENTLY WITH SIGNS OF
INCREASING MOISTURE IN PLACE CURRENTLY. HIGH CLOUDS ARE IN PLACE,
WITH SOME STRATOCUMULUS BEGINNING TO DEVELOP BENEATH THIS DECK OF
HIGH CLOUDS. LATEST OBS AT CAE, OGB, AND AGS NOTE THAT CEILINGS OF 4-
5 KFT HAVE DEVELOPED AS SOUTHEASTERLY FLOW INCREASES LOW-LEVEL
MOISTURE ACROSS THE AREA. GUIDANCE GENERALLY FORECASTS MVFR CEILINGS
TO EVENTUALLY DEVELOP WITH THIS, ALONG WITH SOME SHOWERS, AS
MOISTURE CONTINUES TO INCREASE. THIS IS EXPECTED TO SETTLE INTO THE
AREA SOMETIME AFTER 09Z. THIS REMAINS UNCERTAIN EVEN AT THIS CLOSE
RANGE AS THERE ARE NO OBSERVATIONS, EVEN IN THE DEEPER MOISTURE TO
OUR SOUTHEAST, OF ANYTHING LESS THAN 4KFT AT THIS TIME. SO TIME WILL
TELL. THE FORECAST REALLY DOESN'T GET MUCH EASIER FROM THERE IN
TERMS OF CEILINGS. MORE CONSISTENT SHOWERS LOOK TO BUILD IN DURING
THE AFTERNOON HOURS AFTER 18Z, WITH CEILINGS PROBABLY FALLING TO LOW
MVFR AND IFR RANGE AS WE HEAD INTO THE EVENING AND OVERNIGHT HOURS.
BUT THE GUIDANCE REMAINS FAIRLY SPLIT ON THIS. LAMP GUIDANCE IS (AS
USUAL) AGGRESSIVE, BUT HREF/REFS GUIDANCE IS LESS BULLISH, SHOWING
MILD PROBABILITIES OF MVFR CIGS THROUGH THE DAY UP UNTIL LATE IN THE
PERIOD WHEN INCREASING SUBSIDENCE OVERSPREADS THE AREA FROM THE
WEST. SO UNCERTAINTY IS QUITE HIGH IN THE FORECAST AND DID NOT MAKE
SUBSTANTIAL CHANGES FROM THE PREVIOUS FORECAST AS A RESULT. I DO
THINK THAT MVFR CIGS ARE A REALISTIC MIDDLE GROUND FOR MOST WITH
THIS FORECAST. WINDS ARE EXPECTED OUT OF THE SOUTH AND SOUTHWEST
THROUGH THE PERIOD.
EXTENDED AVIATION OUTLOOK...WIDESPREAD RAIN AND RESTRICTIONS
LIKELY CONTINUE INTO THURSDAY NIGHT BEFORE DRIER AIR MOVES IN ON
FRIDAY BEHIND A COLD FRONT, SLOWLY BRINGING AN END TO
RESTRICTIONS. DRIER AIR LOOKS TO REMAIN IN PLACE FOR THE WEEKEND
WITH LOWER CHANCES FOR RESTRICTIONS.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
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