106
FXUS62 KGSP 080145
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
945 PM EDT WED MAY 7 2025
SYNOPSIS
A STRONG COLD FRONT WILL BRING STRONG TO SEVERE STORMS CAPABLE OF
PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL THURSDAY AFTERNOON INTO
THURSDAY EVENING. THE FRONT STALLS OVER THE SOUTHEAST THIS WEEKEND
INTO EARLY NEXT WEEK KEEPING UNSETTLED WEATHER AROUND. HIGHS WILL
REMAIN ABOVE NORMAL TROUGH FRIDAY BEFORE DROPPING WELL BELOW NORMAL
THIS WEEKEND INTO EARLY NEXT WEEK.
NEAR TERM /THROUGH THURSDAY/
AS OF 940 PM EDT WEDNESDAY: SOME ISOLATED LIGHT SHOWERS CONTINUE
EAST OF I-77 THIS EVENING SO ADDED SOME SLIGHT CHANCE POPS IN FOR
THE NEXT HOUR UNTIL THESE DISSIPATE. OTHERWISE, NO OTHER CHANGES
WERE NEEDED THIS UPDATE. THICK CLOUD COVER CONTINUES BUT GENERALLY
DRY CONDITIONS ARE EXPECTED FOR THE NEXT SEVERAL HOURS.
CLOUDS STICK AROUND THROUGH THE OVERNIGHT PERIOD AND 850MB FLOW OUT
OF THE WEST-NORTHWEST INDICATES BRIEF DRYING WILL PERSIST THROUGH
LATE TONIGHT DUE TO WEAK DOWNSLOPE FLOW. GUIDANCE CONTINUES TO
SUPPORT THE IDEA OF LOW STRATUS AND PATCHY FOG DEVELOPING, ROUGHLY
ACROSS THE WESTERN HALF OF THE FORECAST AREA. ANOTHER AREA OF WEAK
MOISTURE TRANSPORT AND UPPER DIVERGENCE FROM A JETLET PASSING ACROSS
THE CFWA AS THE CLOSED LOW PHASES WITH THE JET STREAK THAT'S
STRETCHED FROM THE SOUTHERN PLAINS THROUGH THE MID-ATLANTIC, TURNING
MORE INTO AN ELONGATED TROUGH. IN THIS CASE, ANOTHER ROUND OF
SHOWERS AND MAYBE AN ISOLATED THUNDERSTORM OR TWO COULD DEVELOP
OVERNIGHT, WITH THE BEST CHANCE OVER THE SOUTHWESTERN THIRD OF THE
CFWA. EXTENSIVE CLOUD COVER AND POSSIBLE CONVECTION WILL LEAD TO
OVERNIGHT LOWS RUNNING UP TO 5 DEGREES ABOVE NORMAL.
THE ELONGATED TROUGH WILL ENCROACH THE CFWA ON THURSDAY AS THE
ATTENDANT COLD FRONT DRAPED FROM THE MID-MS VALLEY THROUGH THE
NORTHEASTERN CONUS GRADUALLY DROPS SOUTHWARD. THE BETTER SYNOPTIC
FORCING WILL REACH THE CFWA BY PEAK HEATING THURSDAY. IN THE
PRESENCE OF THE BOUNDARY AND TROUGH, 30-40 KTS OF DEEP LAYER SHEAR
ARE EXPECTED TO GO ALONG WITH 1000-2000+ J/KG OF MLCAPE. CAMS
SUPPORT THE IDEA OF THE CONVECTION INITIATING ACROSS THE HIGHER
TERRAIN BEFORE GROWING UPSCALE AS THE MOSTLY ORGANIZED CONVECTION
PUSHES EAST ACROSS THE NC PIEDMONT AND NORTHERN UPSTATE. THIS
HAS BEEN THE MOST CONSISTENT SIGNAL WITH LESSER PORTIONS OF THE
GUIDANCE BUILDING FURTHER SOUTH INTO THE REST OF THE CFWA. DRIER
AND MODERATELY STEEP MID- TO LOW-LEVEL LAPSE RATES WITH THE
ALLUDED THERMODYNAMICS IN PLACE SHOULD SUPPORT THE INITIAL HAZARD
BEING LARGE HAIL AND A FEW MICROBURSTS (600-1000 J/KG DCAPE)
BEFORE UPSCALE GROWTH COMMENCES AS THE CONVECTION BECOMES MORE
ORGANIZED AND SUPPORTS MORE OF A STRAIGHT-LINE DAMAGING WIND
THREAT AS THE POTENTIAL FOR AN MCS IS NOT OUT OF THE PICTURE BY THE
END OF THE FORECAST PERIOD. AS A RESULT, THE SLIGHT RISK FOR SEVERE
ACROSS THE AREA (MAINLY ALONG AND NORTH OF I-85) APPEARS WARRANTED.
THE HIGHEST POPS WILL BE IN THE NORTHERN BLUE RIDGE ESCARPMENT AND
SHIFT EAST ACROSS THE NC FOOTHILLS AND PIEDMONT. TEMPERATURES WILL
END UP ~5 DEGREES ABOVE NORMAL FOR MOST LOCATIONS AS BETTER
COMPRESSIONAL HEATING OCCURS WITH THE ENCROACHING FRONTAL BOUNDARY.
SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/
AS OF 200 PM EDT WEDNESDAY: CONVECTION, SOME POSSIBLY SEVERE, WILL
BE ONGOING AT THE START OF THE PERIOD. THE SEVERITY WILL DIMINISH BY
LATE EVENING WITH COVERAGE DIMINISHING OVERNIGHT. ANOTHER ROUND OF
SHOWERS AND SCATTERED STORMS DEVELOPS DURING THE DAY FRIDAY AS A
SHORT WAVE ROTATING AROUND AN UPPER LOW OVER THE MID ATLANTIC
CROSSES THE AREA AND A WAVE MOVES EAST ALONG THE FRONTAL BOUNDARY
STALLED TO OUR SOUTH. INSTABILITY AND SHEAR LOOK TO BE WEAKER THAN
THURSDAY, SO THE SEVERE CHANCE WILL BE MUCH LOWER, BUT NOT NON-
EXISTENT. CONVECTION DIMINISHES MUCH MORE QUICKLY FRIDAY EVENING.
GUIDANCE AGREES ON THE MID ATLANTIC UPPER LOW MOVING EAST ON
SATURDAY AS ANOTHER UPPER LOW DEVELOPS OVER THE LOWER MS RIVER
VALLEY. THEY ALSO AGREE ON HIGH PRESSURE BUILDING INTO THE AREA FROM
THE NORTH WITH SOME AMOUNT OF LOW LEVEL DRY AIR FILTERING IN. THEY
ALSO AGREE ON A WEAK, MOIST SOUTHERLY FLOW DEVELOPING OVER PART OF
THE AREA. THEY DISAGREE ON WHERE THE BOUNDARY BETWEEN THE DRIER AND
MOISTER AIR SETS UP. THEREFORE, HAVE GONE WITH THE MODEL BLEND FOR
POP, WITH HIGHER VALUES OVER THE UPSTATE, NE GA, AND THE MOUNTAINS
WEST OF ASHEVILLE. LITTLE TO NO INSTABILITY IS EXPECTED MINIMIZING
THUNDER CHANCES. THERE WILL BE SOME BRIEF, HEAVY RAINFALL IN THE
STORMS THURSDAY EVENING, BUT LIGHT TO MAYBE MODERATE QPF EXPECTED
THROUGH THE REST OF THE PERIOD. TEMPS NEAR TO A LITTLE ABOVE NORMAL
FRIDAY DROP TO AS MUCH AS 10 DEGREES BELOW NORMAL SATURDAY, WITH THE
COOLER READINGS WHERE PRECIP CHANCES ARE HIGHER.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
AS OF 230 PM EDT WEDNESDAY: GUIDANCE REMAINS IN AGREEMENT ON THE
OVERALL PATTERN WITH SOME DISAGREEMENT ON THE DETAILS. THE UPPER LOW
OVER THE LOWER MS RIVER VALLEY WILL DOMINATE OUR EXPECTED WEATHER AS
IT SPINS IN PLACE SUNDAY, THEN BEGINS A SLOW EASTWARD TREK THROUGH
WEDNESDAY. IF SATURDAY ENDS UP DRIER, THEN THE HYBRID CAD WAITS
UNTIL SUNDAY TO DEVELOP WHEN A BETTER LOW LEVEL MOIST SOUTHERLY FLOW
DEVELOPS BRINGING SHOWERS BACK INTO THE AREA. THE CAD HOLDS ON
MONDAY WITH A CONTINUED MOIST SOUTHERLY LOW LEVEL FLOW AND
WIDESPREAD SHOWERS. THAT SAID, THERE MAY BE SOME EROSION OF THE CAD
SOUTH OF I-85 WHICH COULD SET UP A WARM FRONTAL BOUNDARY AND SOME
THUNDERSTORMS. THE UPPER AND SURFACE LOWS REALLY START MOVING
TUESDAY KEEPING THE MOIST SOUTHERLY LOW LEVEL FLOW OVER THE AREA BUT
HELPING ERODE THE CAD AS THEY MOVE IN. WIDESPREAD SHOWERS AND SOME
THUNDERSTORMS EXPECTED AGAIN. PRECIP FINALLY COMES TO AN END FROM
WEST TO EAST TUESDAY NIGHT AS THE LOWS MOVE EAST OF THE AREA.
HOWEVER, SCATTERED SHOWERS, ESPECIALLY OVER NC, WILL BE POSSIBLE
WEDNESDAY WITH LINGERING MOISTURE. TEMPS REMAIN BELOW NORMAL SUNDAY
AND MONDAY THEN RISE A LITTLE ABOVE NORMAL BY WEDNESDAY.
AVIATION /02Z THURSDAY THROUGH MONDAY/
AT KCLT AND ELSEWHERE: DRY CONDITIONS WILL CONTINUE ACROSS THE NORTH
CAROLINA TERMINALS THROUGH EARLY THURSDAY AFTERNOON BEFORE TSRA
DEVELOPS DURING THE MID TO LATE AFTERNOON HOURS THURSDAY. THUS,
INTRODUCED PROB30S FOR TSRA AND ASSOCIATED RESTRICTIONS ACROSS THE
NC TERMINALS DURING THIS TIMEFRAME ON THURSDAY. SEVERE STORMS ARE
POSSIBLE FOR THE NC TERMINALS WITH DAMAGING WIND GUSTS (58 MPH OR
GREATER) AND LARGE HAIL (1" OR GREATER IN DIAMETER) BEING THE MAIN
HAZARDS. PATCHY FOG MAY DEVELOP AT KAVL OVERNIGHT SO WENT WITH A
TEMPO FOR IFR VSBYS AND MVFR CIGS. FOG SHOULD LIFT SHORTLY AFTER
DAYBREAK. THE SOUTH CAROLINA TERMINALS SHOULD SEE -SHRA REDEVELOP
OVERNIGHT INTO DAYBREAK THURSDAY. THUS, INTRODUCED PROB30S FOR -SHRA
AND ASSOCIATED RESTRICTIONS FROM 09Z-12Z THURSDAY ACROSS THE SC
TERMINALS. KAND HAS THE BEST CHANCE TO SEE IFR CIGS DEVELOP
OVERNIGHT INTO DAYBREAK. TSRA LIKELY WILL NOT MAKE IT TO THE SC
TERMINALS THURSDAY AFTERNOON/EARLY EVENING SO MAINTAINED DRY
CONDITIONS AFTER THE MORNING ACTIVITY. WINDS WILL BECOME CALM TO
LIGHT AND VRB THIS EVENING INTO TONIGHT. WINDS WILL GRADUALLY
INCREASE IN SPEED THROUGHOUT THURSDAY RANGING FROM 4-7 KTS. WIND
DIRECTION WILL TOGGLE MORE S/SW THURSDAY AFTERNOON, BECOMING MORE
VRB BY THURSDAY EVENING.
OUTLOOK: AN UNSETTLED PATTERN WILL LINGER INTO EARLY NEXT WEEK
KEEPING CHANCES FOR SHOWERS AND THUNDERSTORMS AROUND AS WELL AS
ASSOCIATED RESTRICTIONS.
CLIMATE
RECORDS FOR 05-10
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 89 1936 53 1924 65 1927 32 2020
1896 1966
1906
KCLT 94 1896 59 1966 70 1927 38 1906
1889
KGSP 96 1889 56 1924 71 1895 32 1906
RECORDS FOR 05-11
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 89 1889 50 1960 64 1890 30 1966
KCLT 95 1916 58 1924 70 1889 39 1977
1896
1889
KGSP 96 1889 59 1924 69 1963 33 1906
RECORDS FOR 05-12
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 88 1980 44 1960 65 1918 36 1969
1956
1914
KCLT 94 1889 56 1960 69 1896 36 2020
KGSP 99 1916 56 1960 68 1979 38 2020
1933 1989
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...AR
NEAR TERM...AR/CAC
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...AR
CLIMATE...GSP
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