627
FXUS62 KGSP 061713
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
113 PM EDT MON OCT 6 2025
SYNOPSIS
HIGH PRESSURE CONTINUES TO CONTROL THE PATTERN THROUGH TUESDAY, WITH
LOW RAIN CHANCES AND A SLOW WARMING TREND. A COLD FRONT ARRIVES
WEDNESDAY, WHICH WILL BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS
ACROSS THE AREA. MUCH DRIER AND COOLER WEATHER IS EXPECTED BEHIND
THE FRONT DURING THE LATTER HALF OF THE WEEK.
NEAR TERM /THROUGH TUESDAY/
1) A FEW ISOLATED SHOWERS THIS AFTERNOON AND OVERNIGHT ALONG AND
WEST OF I-26.
2) TEMPERATURES WARM INTO THE UPPER 70S AND LOW 80S TODAY.
AS OF 110 PM EDT MONDAY: STARTING OFF THE NEW WEEK IN A RELATIVELY
QUIET PATTERN. ALOFT, THE SOUTHEAST REMAINS IN TYPICALLY BROAD FLOW
WITH AN UPPER LOW ACROSS SOUTHERN CANADA CARVING A TROUGH DOWN INTO
THE MIDWEST. AT THE SURFACE, A STRONG AND PERSISTENT BERMUDA HIGH
AMPLIFIES WESTWARD INTO THE REGION, ADVECTING MOISTURE FROM THE
ATLANTIC. THE CLOUD COVER AND MOISTURE RETURN CARVES AROUND THE CWA
TOWARD THE WEST. HOWEVER, THIS AFTERNOON, THERE COULD BE ENOUGH
INSTABILITY TO PRODUCE A FEW SHOWERS IN NE GEORGIA AND FAR SOUTHERN
ZONES OF UPSTATE SC. AT THIS TIME, CAM GUIDANCE ISN'T EXCITED WITH
MODELED SOUNDINGS DEPICTING AROUND 100 J/KG OF SBCAPE AND WEAK E/SE
FLOW. CANNOT RULE OUT A RUMBLE OF THUNDER SHOULD UPDRAFTS GET TALL
ENOUGH. A FEW SHOWERS COULD LINGER OVERNIGHT ACROSS THE FAR WESTERN
NC MOUNTAINS AS E/SE SURFACE WINDS PROVIDE MODERATE ISENTROPIC
ASCENT. NOTHING SEVERE IS ANTICIPATED AND CONFIDENCE IS LOW FOR EVEN
A FEW ISOLATED SHOWERS. WILL KEEP A SLIGHT CHANCE POP (15-30%)
THROUGH THE EVENING AND OVERNIGHT HOURS FOR THE SOUTHERN PORTION OF
THE CWA. FOR TUESDAY, THE HIGH PRESSURE AXIS WOBBLES WESTWARD,
REDUCING PRECIP CHANCES ACROSS MOST OF THE AREA. THERE COULD BE A
STRAY SHOWER ACROSS THE MOUNTAINS NEAR THE TN/NC BORDER. WILL KEEP A
SLIGHT CHANCE POP (15-20%) IN PLACE FOR THIS AREA. AGAIN, NOTHING
SEVERE IS ANTICIPATED TUESDAY EITHER. TEMPERATURES TODAY IN THE
UPPER 70S AND LOW 80S FOR MOST PLACES IN THE AREA WITH OVERNIGHT
TEMPS REMAINING MILD IN THE 60S, THANKS TO THE SURFACE MOISTURE.
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/
AS OF 1217 PM MONDAY: MODEL GUIDANCE IS IN GOOD AGREEMENT THAT AN
UPPER TROUGH WILL SWING ACROSS THE GREAT LAKES AND OHIO VALLEY
TOMORROW NIGHT INTO WEDNESDAY. THE SOUTHERN APPALACHIANS WILL REMAIN
IN THE BASE OF THE TROUGH WITH THE STRONGEST FORCING FOR ASCENT
DISPLACED NORTH OF THE AREA. NONETHELESS, AT LEAST MODEST HEIGHT
FALLS IN CONCERT WITH THE APPROACH OF A SURFACE COLD FRONT SHOULD
PROVE SUFFICIENT TO INSTIGATE A BAND OF SHOWERS THAT WILL APPROACH
THE MOUNTAINS TOMORROW NIGHT. THIS ACTIVITY IS THEN FORECAST TO
SHIFT EAST ACROSS THE REST OF THE AREA DURING THE DAY ON WEDNESDAY.
AROUND 1000-1500 J/KG OF SURFACE-BASED INSTABILITY MAY BE REALIZED
AHEAD OF THE BOUNDARY DURING PEAK HEATING, BUT POOR LAPSE RATES AND
NEAR PARALLEL FRONTAL ORIENTATION RELATIVE TO THE DEEP-LAYER SHEAR
VECTORS DOENS'T BODE WELL FOR ORGANIZED SEVERE WEATHER, ALTHOUGH AN
ISOLATED STRONG STORM CANNOT BE RULED OUT. OVERNIGHT LOWS TOMORROW
NIGHT WILL BE A GOOD BIT ABOVE AVERAGE OWING TO WIDESPREAD CLOUD
COVER AND DEWPOINTS IN THE MID 60S. DAYTIME HIGHS ON WEDNESDAY,
MAINLY AHEAD OF THE FRONT/PRECIPITATION, WILL ONCE AGAIN BE WARM IN
THE LOW TO UPPER 70S. A FEW READINGS NEAR THE 80 DEGREE MARK CANNOT
BE RULED OUT OWING TO COMPRESSIONAL WARMING AHEAD OF THE BOUNDARY.
NOTICEABLY COOLER AND DRIER AIR ADVECTS INTO THE REGION BEHIND THE
FRONT WEDNESDAY NIGHT INTO THURSDAY AS A SPRAWLING SURFACE HIGH
SETTLES ACROSS THE GREAT LAKES. DAYTIME HIGHS ON THURSDAY MAY
STRUGGLE TO REACH THE 70 DEGREE MARK ACROSS MUCH OF THE AREA.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
AS OF 1258 PM MONDAY: FORECAST CONFIDENCE BEGINS TO LOWER LATE WEEK
INTO THE WEEKEND AS GUIDANCE DEPICTS A TRAILING PIECE OF ENERGY
WITHIN THE SOUTHERN STREAM DIVING ACROSS THE LOWER MISSISSIPPI
VALLEY AND INTO THE SOUTHEAST STATES BY FRIDAY. SEVERAL MEMBERS
ATTEMPT TO CLOSE OFF AN UPPER LOW WHICH THEN INTERACTS WITH A
COASTAL BAROCLINIC ZONE AND INDUCES SURFACE CYCLOGENESIS ALONG THE
CAROLINA COAST. AT THE SAME TIME, A COMPACT CLOSED UPPER LOW IS
PROGGED TO BE DIVING ACROSS THE GREAT LAKES AND INTO THE OHIO
VALLEY, WHICH FURTHER COMPLICATES THE EVOLUTION OF THE SYNOPTIC
PATTERN AND SUBSEQUENT INTERACTION BETWEEN THE TWO CLOSED LOWS. AS
OF THIS WRITING, CURRENT EXPECTATIONS ARE FOR ANY COASTAL LOW AND
ASSOCIATED PRECIPITATION TO REMAIN EAST OF THE AREA WITH DRY AND
COOL NORTHERLY FLOW ON THE WESTERN FLANK OF THE CYCLONE. UNCERTAINTY
IS INTRODUCED WITH REGARDS TO THE GREAT LAKES UPPER LOW AND WHETHER
IT CAN "PULL" THE COASTAL LOW FARTHER NORTHWEST IN RESPONSE TO
LOWERING HEIGHTS. WILL MAINTAIN A DRY FORECAST FOR NOW, BUT WILL
HAVE TO WATCH HOW THE FORECAST EVOLVES THROUGH THE WEEK.
TEMPERATURES SLOWLY MODIFY THROUGH THE END OF THE WEEK INTO THE
WEEKEND, BUT STILL BELOW SEASONAL AVERAGES.
AVIATION /18Z MONDAY THROUGH SATURDAY/
AT KCLT AND ELSEWHERE: A MIX OF VFR/MVFR CONDITIONS TO START THE TAF
PERIOD AS AN AREA OF HIGH PRESSURE OFFSHORE KEEPS LOWER CLOUD COVER
LOCKED IN THIS AFTERNOON AND OVERNIGHT. THERE IS A LOW CHANCE FOR
SHRA AT KGSP/KGMU BUT CONFIDENCE ISN'T ENOUGH TO KEEP THE PROB30
GOING. HOWEVER, WILL KEEP IT FOR KAND FROM 19Z-00Z. OVERNIGHT,
CIGS/VSBY CRASH INTO THE MVFR/IFR RANGE AT ALL TERMINALS, WITH LIFR
POSSIBLE AT KAVL. FOR THIS, A TEMPO IS IN PLACE AT ALL SITES. THE
CONFIDENCE IS NOT AS HIGH FOR KCLT AT THIS TIME, SO WILL KEEP 2SM
FOR VSBY IN THE TEMPO. THIS COULD CHANGE AND IS EXPECTED 11Z-13Z.
CIGS/VSBY RESTRICTIONS WILL BE SLOWER TO COME UP TUESDAY MORNING
WITH MVFR LINGERING INTO THE LATER MORNING HOURS, BEFORE RETURNING
TO VFR BY EARLY AFTERNOON. WINDS SHOULD REMAIN LIGHT AND TOGGLE
BETWEEN E/SE AND E/NE TODAY BEFORE BECOMING SE TOWARD THE END OF THE
TAF PERIOD.
OUTLOOK: A COLD FRONT INCREASES RAIN CHANCES AND RESTRICTIONS,
TUESDAY NIGHT INTO WEDNESDAY NIGHT BEFORE DRIER CONDITIONS RETURN
FOR THE REMAINDER OF THE WEEK/WEEKEND.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...CAC
NEAR TERM...CP
SHORT TERM...TW
LONG TERM...TW
AVIATION...CP
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