362
FXUS62 KCAE 281827
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
227 PM EDT TUE JUL 28 2026
WHAT HAS CHANGED
HEAT ADVISORY EXPANDED EARLIER THIS MORNING. UPDATES TO
MESOANALYSIS/OUTLOOK FOR STORMS THIS EVENING. AVIATION
DISCUSSION UPDATED FOR 18Z TAF.
KEY MESSAGES
- 1. HEAT ADVISORY IN EFFECT UNTIL 8 PM WITH HEAT INDICES UP TO
108F POSSIBLE.
- 2. SEVERE THUNDERSTORMS AND DAMAGING WINDS ARE POSSIBLE LATE
THIS AFTERNOON INTO THE EVENING HOURS. DRIER CONDITIONS THEN
MOVE IN FOR THE LATE WEEK BEFORE RAIN CHANCES INCREASE AGAIN
THIS WEEKEND.
DISCUSSION
- 1. HEAT ADVISORY IN EFFECT UNTIL 8 PM WITH HEAT INDICES UP TO
108F POSSIBLE.
TEMPERATURES ARE APPROACHING THE LOW 90S EARLY THIS AFTERNOON
AND SHOULD TOP OUT IN THE MID 90S IN THE COMING HOURS, THOUGH
SOME SPOTS IN THE UPPER 90S WILL BE POSSIBLE. DEWPOINTS REMAIN
IN THE LOW TO MID 70S AND MAY FLUCTUATE A BIT AS MIXING DEEPENS,
BUT SHOULD SETTLE BETWEEN 69-72F FOR MOST SPOTS AS MOIST
SOUTHWESTERLY FLOW CONTINUES AND MEAN MIXING RATIOS IN THE
LOWEST 100MB CONTINUE TO INCREASE TOWARD 16G/KG. HEAT INDICES
ALREADY RANGE FROM 100-105F, AND COULD TOP OUT AROUND 108F IN
SPOTS OVER THE COMING HOURS, DEPENDING ON HOW MUCH MORE SURFACE
DEW POINTS MIX OUT. THE HEAT ADVISORY WAS EXPANDED TO INCLUDE
LINCOLN, MCCORMICK, AND EDGEFIELD COUNTIES EARLIER THIS MORNING,
BUT IT ALSO REMAINS IN EFFECT ALONG AND SOUTH OF I-20 UNTIL 8PM
THIS EVENING. DEPENDING ON TRENDS IN TIMING FOR CONVECTION,
PORTIONS OF THE ADVISORY MAY BE ALLOWED TO EXPIRE A BIT EARLIER.
- 2. SEVERE THUNDERSTORMS AND DAMAGING WINDS ARE POSSIBLE LATE
THIS AFTERNOON INTO THE EVENING HOURS. DRIER CONDITIONS THEN
MOVE IN FOR THE LATE WEEK BEFORE RAIN CHANCES INCREASE AGAIN
THIS WEEKEND.
LATEST OBS/MESOANALYSIS: WV IMAGERY REVEALS THE MID LEVEL
SHORTWAVE NOW DROPPING INTO PORTIONS OF EASTERN KY, SOUTHERN WV,
AND FAR NW VA, BRINGING WITH IT A BELT OF ENHANCED 40-50 KT
500MB FLOW. A FEW EARLY STORMS POPPED UP IN NORTHERN NC/SOUTHERN
VA, BUT THESE HAVE LARGELY OUTPACED UPPER SUPPORT AND HAVE
DIMINISHED. SURFACE ANALYSIS REVEALS THE COLD FRONT IS NOW
SHIFTING INTO NORTHERN KY, WITH NEW CONVECTION SPAWNING AHEAD OF
IT. THE PREVIOUSLY DISCUSSED ENHANCED KINEMATICS ARE SEEN IN
REGIONAL VAD PROFILES AS WELL WHERE THE LATEST 17Z VAD FROM
ROANOKE VA DISPLAYED ELONGATED HODOGRAPHS WITH NEAR 45 KTS OF
DEEP LAYER SHEAR, BUT ALSO NEARLY 25-30 KTS OF SFC- 1KM SHEAR.
LOOKING DOWN SOUTH INTO OUR CWA, STRONG HEATING AND SURFACE
DEWPOINTS STILL IN THE LOW TO MID 70S HAVE LEAD TO THE
DEVELOPMENT OF ROBUST SBCAPE VALUES ON THE ORDER OF 2500-3000
J/KG, BUT AS LOW LEVEL LAPSE RATES HAVE BEEN STEEPING, A
CORRIDOR OF DCAPE VALUES BETWEEN 1000-1200 J/KG IS SEEN ACROSS
THE NORTHERN FA. IT IS WORTH NOTING THAT AS THE STRONG SHORTWAVE
CONTINUES SHIFTING TOWARD THE MID-ATLANTIC, EFFECTIVE SHEAR
VALUES OVER THE NORTHERN FA ARE ALREADY APPROACHING 25-35 KTS
WITH THE RECENT KCAE VAD PROFILE STARTING TO PICK UP ON ENHANCED
35-45 KT MID LEVEL FLOW.
REMAINDER OF THE AFTERNOON AND EVENING: LITTLE IN WAY OF
CONVECTIVE COVERAGE IS EXPECTED THROUGH ABOUT 20-22Z, AS THE FA
REMAINS SOUTH OF THE FRONT AND UPPER KINEMATICS, BUT CONVECTION
NOW BLOSSOMING IN NORTHEAST KY (ASSOCIATED WITH THE SHORTWAVE
AND FRONT) WILL BE THE MAIN FOCUS. LATEST RADAR TRENDS WOULD PUT
THIS ACTIVITY PUSHING IN NEAR THE PEE DEE BY 00-03Z, BUT THIS
IS SUBJECT TO CHANGE AS THE PROPAGATION SPEED MAY CHANGE AS
BETTER ORGANIZATION OCCURS. THE BIGGER QUESTION BEFORE THE FRONT
NEARS IN THE AFOREMENTIONED TIMEFRAME IS IF ANY DISCRETE/SEMI-
DISCRETE CELLS FORM ACROSS PORTIONS OF NC THAT COULD PUSH INTO
NORTHERN PARTS OF THE AREA. MAJORITY OF 12Z GUIDANCE, INCLUDING
THE MEAN HREF SOLUTION WOULD SUGGEST THIS IS NOT LOOKING LIKELY,
WHICH IS REASONABLE CONSIDERING INCREASED DEBRIS CLOUDINESS IS
CURRENTLY SEEN OVER CENTRAL NC WITH RAP MESOANALYSIS SUGGESTING
LESS INSTABILITY DUE TO THIS. OVERALL, OBSERVATIONAL AND 12Z
GUIDANCE SUPPORT CONVECTION WORKING INTO THE PEE DEE/NORTHERN
MIDLANDS THIS EVENING, BRINGING THE MAIN THREAT OF DAMAGING WIND
GUSTS AND POSSIBLY SOME SMALL HAIL. CONFIDENCE REMAINS LOW IN
THE SOUTHERN EXTENT OF CONVECTION WITH LITTLE GUIDANCE
INDICATING ROBUST STORMS MAKING IT MUCH FURTHER SOUTH THAN
RICHLAND COUNTY (EVEN THIS MAY BE A STRETCH). THE FRONT THEN
WORKS IN OVERNIGHT, WITH DRIER CONDITIONS EXPECTED.
REMAINDER OF FORECAST PERIOD: SOLID AGREEMENT REMAINS IN
ENSEMBLE AND MODEL GUIDANCE THAT BEHIND THE FRONT, MUCH DRIER
AIR WORKS IN WEDNESDAY THROUGH FRIDAY WITH PWAT'S FALLING TO
NEARLY 2-3 STANDARD DEVIATIONS BELOW NORMAL. THIS SHOULD BRING
RELIEF FROM THE HUMIDITY AND NICE WEATHER AS TEMPERATURES REMAIN
NEAR NORMAL. HEADING INTO THE WEEKEND, GLOBAL MODELS INDICATE
ANOTHER SHARP SHORTWAVE ROUNDING THE ROBUST RIDGE (WHICH SHOULD
HAVE RETROGRADED NEAR THE FOUR CORNERS REGION AT THIS POINT).
INCREASED SOUTHWESTERLY FLOW SHOULD BRING RETURNING MOISTURE AND
INCREASED RAIN CHANCES AS THIS WAVE WORKS INTO THE REGION.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
BRIEF MORNING FOG/STRATUS POSSIBLE.
WINDS REMAIN OUT OF THE SOUTHWEST AROUND 10 KNOTS, WITH SOME
GUSTS UP TO 18 KNOTS THROUGH THE AFTERNOON AHEAD OF AN
APPROACHING FRONT. CURRENTLY TAF LOCATIONS ARE VFR, AND OUTSIDE
OF ANY POTENTIAL AFTERNOON/EVENING CONVECTION, VFR SHOULD
PREVAIL. REGIONAL RADAR SHOWING A BATCH OF SHOWERS AND STORMS
MOVING THROUGH WESTERN AND CENTRAL NC EARLY THIS AFTERNOON.
GUIDANCE CONTINUES TO TRACK THIS ACTIVITY SOUTHWARD AHEAD OF THE
APPROACHING COLD FRONT, BUT APPEARS TO KEEP IT NORTH OF MIDLANDS
TAF SITES THROUGH 00Z. THERE REMAINS DIFFERENCES IN THE MODELS
IN REGARDS TO BOTH TIMING AND OVERALL COVERAGE OF ANY
SHOWERS/STORMS AS THEY PROGRESS THROUGH THE AREA, SO CONFIDENCE
REMAINS ON THE LOWER SIDE RIGHT NOW FOR AVIATION IMPACTS. WITH
THAT SAID, DID INCLUDE A MENTION OF PROB30 WITH IFR/MVFR
RESTRICTIONS AROUND MOST TAF SITES THIS EVENING AND INTO THE
OVERNIGHT HOURS, MAINLY AROUND THE MOST LIKELY TIMING OF ANY
ACTIVITY FOR NOW. EXPECT AMENDMENTS LATER AS ACTIVITY GETS
CLOSER IF NEEDED.
AFTER THE FRONT MOVES THROUGH LATE TONIGHT, WINDS WILL BEGIN TO
TURN WESTERLY THEN NORTHWESTERLY AFTER SUNRISE ON WEDNESDAY,
WITH SPEEDS AROUND 5 KNOTS OR SO. VFR WILL PREVAIL WEDNESDAY AS
DRIER AIR PUSHES INTO THE REGION.
EXTENDED AVIATION OUTLOOK...DRIER AIR MOVES IN FOR THE SECOND
HALF OF THE WEEK. NEXT CHANCE FOR RAIN AND RESTRICTIONS NOT
EXPECTED UNTIL THE WEEKEND.
CAE WATCHES/WARNINGS/ADVISORIES
SC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ016-018-022-
025-027>031-035-037-038-041-135>137.
GA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR GAZ040-063>065-
077.
DISCUSSION...DH
AVIATION...73
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