824
FXUS62 KCAE 240553
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
153 AM EDT THU JUL 24 2025
SYNOPSIS
MOISTURE RETURNS TO THE REGION TODAY LEADING TO SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON AND
EVENING. BUILDING HIGH PRESSURE OVER THE WEEKEND INTO EARLY NEXT
WEEK WILL RESULT IN LESS CONVECTION BUT THE POTENTIAL FOR A
PROLONGED PERIOD OF DANGEROUS HEAT AND HUMIDITY.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- INCREASING MOISTURE AND HUMIDITY TODAY
- SCATTERED MORNING SHOWERS OVER THE EASTERN MIDLANDS AND LOWER
CSRA WITH SCATTERED THUNDERSTORMS ACROSS THE AREA THIS
AFTERNOON.
THE BRIEF RESPITE IN HEAT AND HUMIDITY IS ALMOST OVER
UNFORTUNATELY AS MOISTURE HAS ALREADY BEGUN ITS RETURN WITH
DEWPOINTS UP ALMOST 10 DEGREES IN PLACES OVER THE PAST 12 HOURS.
CURRENT WV IMAGERY SHOWS THE AXIS OF DRIER AIR ALOFT OVER THE
MIDLANDS WHILE SATELLITE DERIVED PWATS SHOWS A GRADIENT ACROSS
THE AREA FROM AROUND 1.25 INCHES WESTERN MIDLANDS TO 1.75 IN THE
EASTERN MIDLANDS.
AN INVERTED SURFACE TROUGH WAS NOTED OFFSHORE AND IS EXPECTED
TO MOVE INLAND THROUGH THE DAY TODAY BRINGING THE AXIS OF HIGHER
PWATS (AROUND 2.2 TO 2.3 INCHES) ACROSS THE FORECAST AREA. THE
LOW LEVEL CONVERGENCE COMBINED WITH ABUNDANT MOISTURE WITH SOME
MODERATE INSTABILITY THAT DEVELOPS WITH DIURNAL HEATING SHOULD
RESULT IN SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WITH
THE HIGHEST CHANCES EXPECTED OVER THE EASTERN MIDLANDS AND CSRA.
OVERALL SEVERE WEATHER THREAT APPEARS LOW WITH GENERALLY WEAK
SHEAR BUT CANNOT RULE OUT AN ISOLATED STRONG TO SEVERE STORM
WITH SOME DAMAGING WIND GUST POTENTIAL DUE TO DCAPE VALUES
AROUND 1000 J/KG AND AN INVERTED-V SIGNATURE IN FORECAST
SOUNDINGS. AN ISOLATED URBAN FLASH FLOOD THREAT APPEARS MORE
LIKELY GIVEN THE SLOW MOVING NATURE OF POSSIBLE CONVECTION WITH
TRAINING AND AROUND 10KFT DEEP WARM LAYER PROVIDING EFFICIENT
PRECIPITATION PROCESSES. TEMPERATURES SHOULD AGAIN BE SIMILAR TO
WEDNESDAY AND NEAR NORMAL WITH HIGHS IN THE LOWER 90S SOMEWHAT
LIMITED BY CLOUD COVER AND PRECIPITATION.
TONIGHT, SOME LINGERING SHOWERS ARE EXPECTED ACROSS THE CENTRAL
AND WESTERN MIDLANDS AS THE WEAK INVERTED TROUGH CONTINUES TO
SHIFT WESTWARD BUT CHANCES OF RAIN SHOULD DIMINISH AFTER
MIDNIGHT ONCE THE ATMOSPHERE STABILIZES. OVERNIGHT LOWS EXPECTED
TO BE IN THE LOWER TO MID 70S.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
KEY MESSAGE(S):
- BUILDING RIDGE WILL RESULT IN WARMING TEMPERATURES AND RAIN-
FREE CONDITIONS.
AN UPPER LEVEL RIDGE BECOMES ESTABLISHED OVER THE REGION AND
STRENGTHENS THROUGH SATURDAY. AT THE SURFACE HIGH PRESSURE
BUILDS JUST OFF THE SOUTHEAST COAST, AND THERE ARE SOME
INDICATIONS THAT A WEAK BACKDOOR COLD FRONT COULD DROP SOUTH AN
STALL NEAR/JUST NORTH OF THE AREA ON SATURDAY. STRONG SUBSIDENCE
ALONG WITH A LACK OF DEEP MOISTURE OR FORCING MECHANISM WILL
GENERALLY RESULT IN RAIN-FREE CONDITIONS. HIGH TEMPERATURES WILL
TREND UPWARD BOTH DAYS, NEARING TRIPLE DIGIT VALUES IN SOME
AREAS BY SATURDAY. FORTUNATELY, DEW POINT VALUES SHOULD MIX OUT
SUFFICIENTLY TO KEEP HEAT INDEX VALUES BELOW HEAT ADVISORY
CRITERIA, AND THIS IS SUPPORTED WITH THE LREF WHICH HAS THE
PROBABILITY OF REACHING HEAT ADVISORY CRITERIA (108F) AT LESS
THAN 20% AT ANY LOCATION IN THE FORECAST AREA.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
KEY MESSAGE(S):
- POTENTIAL FOR A PROLONGED, DANGEROUS HEAT EVENT LATE THIS
WEEKEND INTO NEXT WEEK.
THERE IS AN INCREASING SIGNAL IN THE ENSEMBLE GUIDANCE THAT
DANGEROUS HEAT COULD DEVELOP LATE THIS WEEKEND AND PERSIST INTO
NEXT WEEK. UPPER LEVEL RIDGING CENTERED OVER THE SAVANNAH RIVER
AT THE START OF THE PERIOD WILL GRADUALLY RETROGRADE TO THE WEST
THROUGH MONDAY WHILE STRENGTHENING. HOWEVER, THE EASTERN
PERIPHERY OF THE RIDGE COULD BEGIN TO ERODE CLOSER TO THE MIDDLE
OF NEXT WEEK.
BLENDED AND DETERMINISTIC TEMPERATURE GUIDANCE CONTINUES TO
TREND UPWARD, WITH LREF PROBABILITIES OF HIGH TEMPERATURES OF
100F OR MORE NOW GREATER THAN 75% FOR MOST OF THE FORECAST AREA
BOTH SUNDAY AND MONDAY, WITH SOMEWHAT LOWER PROBABILITIES
TUESDAY AND WEDNESDAY AS THE RIDGE BEGINS TO ERODE. HEAT INDEX
VALUES WILL BECOME CONCERNING FOR AT LEAST SUNDAY AND MONDAY,
AND LIKELY EXTENDING INTO THE MIDDLE OF NEXT WEEK. EXPECT HEAT
ADVISORIES TO BE NEEDED, WITH A SMALL POTENTIAL FOR HEAT INDEX
VALUES TO APPROACH EXTREME HEAT WARNING CRITERIA.
AS FOR PRECIPITATION CHANCES, STRONG SUBSIDENCE WILL GENERALLY
KEEP THE COVERAGE OF ANY SHOWERS AND THUNDERSTORMS TO ISOLATED
AT MOST ON SUNDAY, WITH MORE SCATTERED STORMS ON MONDAY. THE
ERODING RIDGE COULD ALLOW TO A SLIGHTLY GREATER COVERAGE OF
STORMS TOWARD MID WEEK, AND THAT TOO CAN AFFECT DAYTIME
HIGHS/HEAT INDEX VALUES.
AVIATION /06Z THURSDAY THROUGH MONDAY/
GENERALLY VFR CONDITIONS EXPECTED OUTSIDE OF CONVECTION,
ALTHOUGH POSSIBLE RESTRICTIONS IN STRATUS THIS MORNING AT
OGB/AGS/DNL WITH HIGHEST CONFIDENCE AT OGB. MOISTURE WILL BE
INCREASING THROUGH THE MORNING AS AN INVERTED SURFACE TROUGH
PUSHES ONSHORE AND INTO THE MIDLANDS THROUGH THE DAY. EXPECT
SCATTERED MORNING SHOWERS ACROSS THE EASTERN MIDLANDS AND
POSSIBLE AFTERNOON STORMS ACROSS THE AREA TODAY WITH INCREASED
MOISTURE AND WILL INCLUDE A PROB30 TO ACCOUNT FOR THIS. WINDS
WILL PICK UP FROM THE EAST AROUND SUNRISE AND INCREASE TO AROUND
6 TO 9 KNOTS BY LATE MORNING AND GRADUALLY SHIFT MORE EAST-
SOUTHEASTERLY THIS AFTERNOON BEFORE GOING LIGHT AND VARIABLE
AGAIN AFTER SUNSET.
EXTENDED AVIATION OUTLOOK...TYPICAL SUMMERTIME AFTERNOON
CONVECTION COULD BRING PERIODS OF RESTRICTIONS FRIDAY AND OVER
THE WEEKEND. OUTSIDE OF THIS, VFR CONDITIONS SHOULD GENERALLY
PREVAIL. VFR CONDITIONS EXPECTED TO PREVAIL.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
SYNOPSIS...HC/JAQ
NEAR TERM...HC
SHORT TERM...JAQ
LONG TERM...JAQ
AVIATION...HC
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