428
FXUS62 KCAE 100145
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
945 PM EDT WED JUL 9 2025
SYNOPSIS
A BIT COOLER TODAY WITH WIDESPREAD SHOWERS AND STORMS LIKELY AS
AN UPPER TROUGH APPROACHES. THE THREAT FOR DAMAGING WINDS AND
FLASH FLOODING WILL EXIST BOTH TODAY AND THURSDAY WITH HEAVY
RAINFALL EXPECTED. THE UPPER TROUGH IS REPLACED BY RIDGING LATE
IN THE WEEK AND THIS WEEKEND, ALLOWING TEMPERATURES TO SLOWLY
RISE WITH TYPICAL SUMMERTIME SHOWERS AND STORMS.
NEAR TERM /UNTIL 7 AM THURSDAY MORNING/
KEY MESSAGE(S):
- ISOLATED TO SCATTERED CONVECTION OVERNIGHT WITH POSSIBLE FLASH
FLOOD THREAT.
WIDESPREAD CONVECTION HAS DIMINISHED ACROSS THE FORECAST AREA
THIS EVENING BUT REGIONAL RADAR SHOWS ADDITIONAL SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS CENTRAL GA MOVING
TOWARD THE UPPER CSRA POSSIBLY DRIVEN BY WEAK SHORTWAVE ENERGY
ON THE LEADING EDGE OF THE UPPER TROUGH AXIS. THE ATMOSPHERE
REMAINS QUITE CONDUCIVE FOR HEAVY RAINFALL WITH PWATS AROUND
1.9-2.1 INCHES AND DEWPOINTS GENERALLY IN THE LOWER 70S. HI-RES
GUIDANCE SUGGESTS THIS ACTIVITY WILL SLOWLY MOVE INTO THE AREA
OVERNIGHT IMPACTING THE NORTHERN AND CENTRAL MIDLANDS THROUGH
THE NIGHT. SEVERE STORM THREAT APPEARS LOW WITH SOME
STABILIZATION OF THE ATMOSPHERE WHERE WIDESPREAD RAIN OCCURRED
AND THINK THE FLASH FLOOD THREAT IS HIGHER, ALTHOUGH
MESOANALYSIS CONTINUES TO SHOW MLCAPE VALUES 1500-2000 J/KG
ALONG THE I-85 CORRIDOR INTO THE WESTERN MIDLANDS. WIDESPREAD
CLOUD COVER AND ADDITIONAL PRECIPITATION LIKELY TO LIMIT
RADIATIONAL COOLING AND WITH TEMPERATURES ALREADY IN THE LOWER
TO MID 70S, OVERNIGHT LOWS SHOULD NOT BE TOO FAR OFF FROM THESE
VALUES. PATCHY TO POSSIBLY WIDESPREAD STRATUS/FOG CANNOT BE
RULED OUT GIVEN THE AMOUNT OF RAIN THAT OCCURRED OVER PARTS OF
THE FORECAST AREA.
SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/
KEY MESSAGE(S):
- POTENTIAL FOR STRONG TO MARGINALLY SEVERE STORMS MAINLY
THURSDAY, BUT POSSIBLE AGAIN ON FRIDAY.
- THE FLASH FLOOD POTENTIAL CONTINUES THROUGH THE SHORT TERM AS
HIGH MOISTURE AND WEAK STEERING FLOW CONTINUES.
AN ACTIVE SHORT TERM PERIOD CONTINUES TO BE EXPECTED AS THE
UPPER TROUGH WORKS THROUGH THE FA THURSDAY BEFORE BEGINNING TO
EXIT TOWARD FRIDAY EVENING AND OVERNIGHT. FORCING FROM THE
TROUGH WILL CONTINUE TO INFLUENCE SENSIBLE WEATHER EACH DAY
WHERE THE WHOLE CWA IS OUTLINE IN A SLIGHT RISK (LEVEL 2 OUT OF
5) FOR SEVERE WEATHER ON THURSDAY AND A MARGINAL RISK ON FRIDAY
(LEVEL 1 OUT OF 5). FOR THURSDAY, WEAK UPPER FORCING ALONG WITH
SOME SURFACE MOISTURE CONVERGENCE SHOULD DRIVE SCATTERED TO
WIDESPREAD SHOWERS AND STORMS ACROSS THE AREA DURING THE
AFTERNOON/EVENING. THE ENVIRONMENT HAS LONG SKINNY CAPE PROFILES
WITH MLCAPE ON THE ORDER OF 2000-2500 J/KG AND PWAT'S THAT
REMAIN NEAR 2.0-2.2", THOUGH THE DEGREE IN WHICH THE ATMOSPHERE
DESTABILIZES IS A BIT UNCERTAIN AS INCREASED CLOUD COVER IS
EXPECTED THURSDAY MORNING INTO THE AFTERNOON. DEEP LAYER SHEAR
REMAINS WEAK, BUT HAS SLIGHTLY INCREASED FROM PREVIOUS FORECAST
SOUNDINGS TO AROUND 15 KTS. DUE TO THIS, A COUPLE LOOSELY
ORGANIZED CLUSTERS COULD FORM AND POSSIBLY GROW UPSCALE SOME IF
A STRONG COLD POOL DEVELOPS. THE VERY MOIST SOUNDINGS, AND AT
LEAST MODESTLY STEEP 0-3KM LAPSE RATES, BRING THE MAIN THREAT OF
DAMAGING WINDS FROM POTENTIAL WET DOWNBURSTS, BUT THE OTHER
CONCERN, ESPECIALLY DEPENDING ON WHICH LOCATIONS SEE RAINFALL
TODAY, WILL BE THE POTENTIAL FOR ISOLATED SPOTS OF FLASH
FLOODING. CURRENTLY, THE CWA IS OUTLINED IN WPC'S MARGINAL RISK
(LEVEL 1 OUT OF 4) FOR EXCESSIVE RAINFALL THURSDAY BUT A SLIGHT
RISK (LEVEL 2 OUT OF 4) DOES EXTENDED INTO THE PEE DEE REGION.
WITH WEAK STEERING FLOW ONCE AGAIN OVERHEAD, SLOW STORM MOTIONS
ARE EXPECTED AND WHEN COUPLED WITH LONG/SKINNY CAPE PROFILES
OVER A DEEPLY MOIST ATMOSPHERIC COLUMN, EFFICIENT RAINFALL IS
LIKELY WHERE THE 12Z HREF LPPM HIGHLIGHTS LOCALIZED SPOTS OF
2-4" BEING POSSIBLE. AGAIN, THE AREAS AT HIGHEST RISK FOR THIS
POTENTIAL WILL PARTIALLY BE DRIVEN BY RAINFALL RECEIVED TODAY
AND HOW SOIL MOISTURES AND LOCAL BASINS RESPOND. THIS ACTIVITY
IS EXPECTED TO DWINDLE IN COVERAGE AND INTENSITY INTO THE
OVERNIGHT HOURS.
FRIDAY SEES THE TROUGH PIVOT OVERHEAD AND FINALLY OUT OF THE
REGION BY THE EVENING AND OVERNIGHT, THOUGH PWATS REMAIN NEAR 2"
STILL WITH A POSSIBLE SHORTWAVE THAT REACHES THE FA BY THE
EARLY AFTERNOON. THIS SHOULD DRIVE ANOTHER ROUND OF SCATTERED TO
WIDESPREAD SHOWERS/STORMS, WITH A COUPLE ON THE STRONG SIDE
POSSIBLE, AGAIN DUE TO THE POTENTIAL FOR DOWNBURST WINDS FROM
PRECIP LOADED DOWNDRAFTS AS SHEAR AND STEERING FLOW REMAIN WEAK.
LIKE THURSDAY, SOME ENHANCED CLOUD COVER TO START THE DAY
BRINGS IN UNCERTAINTY IN HOW MUCH INSTABILITY CAN BUILD. WITH
PWAT'S SLOWLY LOWERING DUE TO MOISTURE TRANSPORT VECTORS TURNING
A BIT MORE WESTERLY AND UPPER FORCING SLOWLY MOVING OUT, THE
POTENTIAL FOR ISOLATED FLASH FLOODING IN SPOTS IS A BIT LOWER
THAN THURSDAY, THOUGH THIS COULD EASILY CHANGE BASED ON WHERE
SLOW-MOVING CONVECTION MOVES OVER TODAY AND THURSDAY.
SHOWERS/STORMS LOOK TO MOVE OUT WITH THE UPPER SUPPORT DURING
THE EVENING AND OVERNIGHT AS RIDGING SLOWLY REPLACES THE TROUGH.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
KEY MESSAGE(S):
- TEMPERATURES RETURN TO ABOVE NORMAL VALUES THIS WEEKEND INTO
MONDAY AS UPPER RIDGING REDEVELOPS.
- SHOWER/STORM CHANCES BECOME MORE DIURNALLY DRIVEN.
UPPER RIDGING CONTINUES TO BE EXPECTED TO TAKE GRIP THROUGH THE
WEEKEND AND INTO THE EARLY WEEK, LEADING TO INCREASED TEMPERATURES
AND HEAT INDICES THAT NEAR 105F MAINLY SUNDAY AND MONDAY. RETURNING
SEASONABLE MOISTURE UNDER THE RIDGE BRINGS TYPICAL DIURNAL
SHOWER/STORM CHANCES EACH DAY BEFORE THERE IS A LEAST A WEAK SIGNAL
IN GLOBAL MODELS THAT THE RIDGE COULD BREAK DOWN SLIGHTLY TOWARD
TUESDAY, POSSIBLY BRINGING CLOSER TO NORMAL TEMPERATURES AND
INCREASED POP'S EACH DAY.
AVIATION /01Z THURSDAY THROUGH MONDAY/
LINGERING SHOWERS CONTINUING OVER THE TERMINALS, ALTHOUGH THERE
ARE NOT LEADING TO ANY RESTRICTIONS. WITH WIDESPREAD RAINFALL
TODAY, ANOTHER CHANCE TONIGHT THAT RESTRICTIONS DEVELOP OVER THE
TERMINALS AS MVFR FOG OR CEILINGS WITH PLENTIFUL LOW LEVEL
MOISTURE IN PLACE. GUIDANCE STILL REMAINS MIXED ON THIS
POTENTIAL, HOWEVER, SO HAVE INCLUDED IT IN A TEMPO GROUP. ALSO
UNCERTAINTY AS TO SOME CONVECTION TO THE WEST OF THE TERMINALS,
BUT HIRES GUIDANCE CONTINUES TO INDICATE IT WILL DISSIPATE AS IT
APPROACHES THE TERMINALS. ADDITIONAL CONVECTION DEVELOPS
TOMORROW AFTERNOON BUT UNCERTAIN THAT IT WILL BE BEFORE 18Z.
EXTENDED AVIATION OUTLOOK...THERE IS THE POSSIBILITY OF
DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS THIS WEEK WITH THE
POTENTIAL FOR PERIODIC RESTRICTIONS.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
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