739
FXUS62 KGSP 040642
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
242 AM EDT SAT APR 4 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES TO THE TIMING AND EXPECTED RAINFALL AMOUNTS
ASSOCIATED WITH THE COLD FRONT TONIGHT THROUGH SUNDAY.
LOW TEMPERATURES CONTINUE TO TREND SLIGHTLY UPWARD DURING THE
EARLY TO MIDDLE PART OF THE NEXT WEEK.
UPDATED FOR THE THE 06Z AVIATION DISCUSSION.
KEY MESSAGES
1. WELL ABOVE NORMAL AND HUMID WITH ISOLATED TO SCATTERED DIURNAL
SHOWERS AND THUNDERSTORMS POSSIBLE TODAY.
2. THE PASSAGE OF A COLD FRONT SUNDAY WILL BRING THE BEST RAIN
CHANCES OVER THE NEXT WEEK. THE RISK OF FLOODING RAIN OR SEVERE
WEATHER APPEARS TO BE LOW.
3. COLD AIR COULD BRING FROST OR A FREEZE TO PARTS OF THE NC
MOUNTAINS, FOOTHILLS, AND NORTHWEST PIEDMONT EACH NIGHT FROM
SUNDAY NIGHT THROUGH WEDNESDAY NIGHT. THE MOST LIKELY TIME WOULD
BE TUESDAY NIGHT. PROTECTION OF SENSITIVE VEGETATION MIGHT BE
NECESSARY.
DISCUSSION
KEY MESSAGE 1: WELL ABOVE NORMAL AND HUMID WITH ISOLATED TO SCATTERED
DIURNAL SHOWERS AND THUNDERSTORMS POSSIBLE TODAY.
A BERMUDA HIGH WILL CONTINUE TO INFLUENCE OUR WEATHER TODAY, WITH
HIGHS 10-13 DEG ABOVE NORMAL AND DEWPTS IN THE 60S, MAKING IT FEEL
HUMID. MEANWHILE, HEIGHTS ALOFT WILL BEGIN TO FALL, AS AN UPPER
TROUGH CROSSES THE MIDWEST. THE HEIGHT FALLS SHOULD HELP STEEP
MID-LEVEL LAPSE RATES AND ERODE A MID-LEVEL CAP THAT WAS IN PLACE
YESTERDAY. MODEL CONSENSUS SHOWS UP TO 1000 J/KG OF SBCAPE BY PEAK
HEATING. DIFFERENTIAL HEATING AND PERHAPS SOME WEAK UPGLIDE SHOULD
TRIGGER AT LEAST SCATTERED CONVECTION ACROSS THE WESTERN HALF OF
THE FORECAST AREA BY EARLY AFTN, THEN DRIFTING NE LATE AFTN INTO
THE EVENING. THE 00Z CAMS ARE IN DECENT AGREEMENT ON THE ACTIVITY
REMAINING UNORGANIZED. BULK SHEAR WILL REMAIN RATHER WEAK, AND
OVERALL FORCING AND MODEST CAPE SHOULD KEEP ANY SEVERE THREAT
LOW. BUT A FEW SUB-SEVERE STRONG STORMS MAY BE POSSIBLE. POPS
WILL RANGE FROM 30% IN THE FAR EASTERN ZONES TO AROUND 80% IN THE
NORTHERN NC MOUNTAINS.
KEY MESSAGE 2: THE PASSAGE OF A COLD FRONT SUNDAY WILL BRING THE
BEST RAIN CHANCES OVER THE NEXT WEEK. THE RISK OF FLOODING RAIN
OR SEVERE WEATHER APPEARS TO BE LOW.
AN UPPER TROUGH WILL CONTINUE TO PROGRESS FROM THE MID-MS VALLEY TO
THE OH VALLEY SATURDAY THRU SUNDAY, BRINGING A FAIRLY STRONG COLD
FRONT INTO THE FORECAST AREA. GUIDANCE IS IN REALLY GOOD AGREEMENT
ON THE TIMING OF THE FRONT AND ASSOCIATED PRECIPITATION. THIS STILL
MEANS A LATE SATURDAY NIGHT THRU EARLY SUNDAY AFTN TIME FRAME FOR
CONVECTION. A LACK OF INSTABILITY LOOKS TO BE THE LIMITING FACTOR
IN ANY HEAVY RAIN AND SEVERE THREATS. THE 00Z CAMS ARE IN DECENT
AGREEMENT ON A QLCS TRACKING ACROSS CENTRAL KY/TN, BUT LOSING
ORGANIZATION AND OVERALL WEAKENING BEFORE EVEN REACHING THE NC
MOUNTAINS AROUND OR JUST AFTER MIDNIGHT. SO IT IS LOOKING LIKE A
GENERALLY BROAD BAND OF SHOWERS WITH A FEW EMBEDDED TSTMS CROSSING
THE MOUNTAINS OVERNIGHT, AND ENTER THE PIEDMONT AROUND DAYBREAK
SUNDAY. THE LINE WILL THEN CONTINUE TO PUSH EAST AND LARGELY EXIT
THE SE EDGE OF THE FORECAST AREA BY SUNSET. THERE COULD BE SOME
INCREASING INSTABILITY AHEAD OF THE FRONT TO ALLOW CONVECTION TO
STRENGTHEN, BUT ANY UPTICK IN SEVERE THREAT LOOKS TO BE TO OUR EAST.
IN ADDITION TO ANY NON-ZERO SEVERE THREAT, WE COULD SEE SOME
BENEFICIAL RAINFALL ACROSS THE AREA, ESPECIALLY IN THE SW-FACING
SLOPES OF THE MOUNTAINS. BUT WITH THE LACK OF INSTABILITY AND
THE PROGRESSIVE NATURE OF THE CONVECTION, ANY EXCESSIVE RAINFALL
LOOKS UNLIKELY. SOME FAVORABLE SLOPES COULD SEE 1-2" OF RAINFALL
IN A 6-HOUR PERIOD, WHICH GIVEN THE DROUGHT, SHOULD NOT RESULT IN
FLOODING. THE REST OF THE AREA COULD SEE HALF AN INCH TO AN INCH
OF RAINFALL.
KEY MESSAGE 3: COLD AIR COULD BRING FROST OR A FREEZE TO PARTS OF
THE NC MOUNTAINS, FOOTHILLS, AND NORTHWEST PIEDMONT EACH NIGHT
FROM SUNDAY NIGHT THROUGH WEDNESDAY NIGHT. THE MOST LIKELY TIME
WOULD BE TUESDAY NIGHT. PROTECTION OF SENSITIVE VEGETATION MIGHT
BE NECESSARY.
THE NEW MODEL GUIDANCE CONTINUES TO SHOW A PERIOD OF COOLER AND
DRIER WEATHER THROUGH AT LEAST THE MIDDLE PART OF THE WEEK AS AN
INITIAL CONTINENTAL SFC HIGH BUILDS IN BEHIND THE FRONT EARLY IN
THE WEEK, AND THEN THE COOL AIR MASS GETS A REINFORCEMENT FROM A
STRONGER HIGH MOVING ALONG IN THE NORTHERN STREAM TUESDAY NIGHT
AND WEDNESDAY. THE SECOND HIGH WILL ESSENTIALLY BRING A DRY WEDGE
TO THE FCST AREA FROM WEDNESDAY THROUGH THE REST OF THE WEEK. THE
MAIN CONCERN CONTINUES TO BE THE OVERNIGHT LOW TEMPS MAINLY OVER
THE MTNS AND I-40 CORRIDOR, HOWEVER THE NEW MODEL BLEND CONTINUES
THE SLIGHTLY UPWARD TREND. THE PROBS FOR TEMPS GETTING BELOW 32F
SUNDAY AND MONDAY NIGHT ARE CONFINED ONLY TO ELEVATIONS ABOVE 5K
FT AND REMAIN VERY LOW AT ANY RATE. WIND MIGHT ALSO PROVE TO BE
STEADY ENOUGH OVERNIGHT TO INHIBIT FROST FORMATION BECAUSE OF
THE PERSISTENT PRESSURE GRADIENT ACROSS THE MTNS. OPTED NOT TO
INTRODUCE ANY FROST WORDING YET BECAUSE OF THIS SLOW WARMING TREND
AND BECAUSE THE CENTRAL/SOUTHERN MOUNTAIN ZONES DON'T BECOME ACTIVE
UNTIL TOMORROW. TUESDAY NIGHT STILL LOOKS LIKE THE BEST CHANCE
TO HAVE FROST/FREEZE ISSUES AFTER THE REINFORCING FRONT CROSSES
THE REGION, BUT THE LATEST BLEND KEEPS AREAS OUTSIDE THE NORTHERN
MOUNTAINS IN THE MIDDLE 30S, THUS A FREEZE MIGHT NO LONGER BE ON
THE TABLE. FROST STILL LOOKS LIKE A DECENT BET, THOUGH. BY WEDNESDAY
NIGHT, THE AIR MASS MODIFIES ENOUGH TO MITIGATE THE CONCERN.
AS A REMINDER, THE FROST/FREEZE PROGRAM WILL BE ACTIVATED ON 5
APRIL FOR THE MOUNTAIN ZONES ALONG AND SOUTHWEST OF I-26 AND ALSO
FOR THE NC PIEDMONT I-40 CORRIDOR (GREATER MCDOWELL EAST TO ROWAN,
AND NORTH). IT IS ALREADY ACTIVE IN AREAS TO THE SOUTH. AS THE
FORECAST STANDS, A FROST ADVISORY IS A GOOD BET ACROSS PARTS OF
THE MTNS AND FOOTHILLS EARLY WEDNESDAY. UNFORTUNATELY, THIS ALSO
SETS UP THE CONFUSING SITUATION WHERE THE NORTHERN MOUNTAINS MIGHT
GET BELOW FREEZING BUT HAVE NO WARNING ISSUED BECAUSE THOSE ZONES
DO NOT BECOME ACTIVE UNTIL 21 APRIL. THAT BEING THE CASE, WE WILL
HAVE TO LET THE FCST SPEAK FOR ITSELF.
WITH RESPECT TO FIRE WEATHER, RH LOOKS LIKELY TO DROP BELOW
30 PERCENT ACROSS THE AREA EACH AFTERNOON FROM MONDAY THROUGH
WEDNESDAY, THOUGH WITH GENERALLY LIGHT WINDS. FUEL MOISTURE WILL
HAVE TO BE MONITORED. FIRE DANGER WILL LIKELY INCREASE DURING THIS
PERIOD. TEMPERATURES BOTTOM OUT WEDNESDAY AROUND FIVE DEGREES
BELOW NORMAL, BUT WILL REBOUND TO NORMAL THURSDAY AS THE PARENT
HIGH MOVES OFF THE NORTHEAST COAST. FOR THE REST OF THE PERIOD,
A GRADUAL WARMING TREND IS EXPECTED WITH INCREASING MOISTURE,
WHICH SHOULD IMPROVE THE FIRE WEATHER SITUATION ONCE AGAIN.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
AT KCLT AND ELSEWHERE: GUIDANCE HAS BACKED OFF THE LOW MVFR TO
IFR CIGS THIS MORNING, BUT STILL EXPECT AT LEAST SOME MVFR CIGS
ACROSS THE UPSTATE SITES DEVELOPING RIGHT AROUND OR JUST BEFORE
DAYBREAK. THE CLOUDS MAY SPREAD NE TOWARD KCLT AND KHKY, BUT
GUIDANCE IS MIXED, SO CONFIDENCE IS LOW. THERE IS POTENTIAL THAT
THE CONVECTIVE CU FIELD MAY START OUT BELOW 3000 FT BEFORE LIFTING
TO 3500 TO 5000 FT THIS AFTN. AS FOR CONVECTION, SPOTTY SHOWERS
HAVE DEVELOPED THANKS TO UPSLOPE FLOW NEAR THE NC/SC BORDER. FOR
NOW, WILL GO WITH VCSH AT KAND, WHERE THE BEST CHANCE OF SEEING
SHRA EARLY THIS MORNING. STILL EXPECT SCATTERED SHRA AND TSRA TO
DEVELOP ACROSS THE AREA THIS AFTN, WITH PROB30S PLACED DURING TIME
PERIOD OF HIGHEST CHANCES. LIGHT S TO SW WIND TONIGHT PICKS BACK
UP DURING THE DAY, WITH LOW END GUSTS FOR THE AFTERNOON. A LULL
IN CONVECTION EXPECTED THIS EVENING AHEAD OF A LINE OF SHOWERS
AND STORMS APPROACHING FROM THE WEST. A PROB30 FOR TSRA WAS ADDED
AT KAVL, AS THERE IS A CHANCE CONVECTION MAY ARRIVE TOWARD END OF
TAF PERIOD.
OUTLOOK: A COLD FRONT BRINGS BETTER CHANCES FOR SHRA/TSRA AND
ASSOCIATED RESTRICTIONS LATE TONIGHT INTO SUNDAY ACROSS THE
TERMINALS. HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE FRONT
SUNDAY NIGHT INTO THE MIDDLE OF NEXT WEEK ALLOWING DRY AND VFR
CONDITIONS TO RETURN.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
ARK/PM
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