482  
FXUS62 KGSP 311624  
AFDGSP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC  
1224 PM EDT MON MAR 31 2025  
   
SYNOPSIS  
 
SHOWER AND THUNDERSTORM ARE EXPECTED TO CROSS THE AREA TODAY  
AHEAD OF AN APPROACHING COLD FRONT. A FEW OF THESE STORMS COULD  
BE SEVERE. THE FRONT PUSHES THRU TONIGHT, AND USHERS IN DRY HIGH  
PRESSURE FOR TUESDAY. THE HIGH WILL SETTLE OFF THE SOUTHEAST  
COAST AND KEEP WARM SOUTHERLY FLOW ACROSS THE REGION, RESULTING  
IN WELL-ABOVE-NORMAL TEMPERATURES THROUGH THE END OF THE WEEK.  
 
 
   
NEAR TERM /THROUGH TONIGHT/  
 
AS OF 1211 PM MONDAY: UPDATE FOR SVR TSTM WATCH THRU 23Z FOR  
NORTHEAST GA/UPSTATE SC, AND ROW OF ZONES ALONG NC/SC BORDER  
INCLUDING MOST OF METRO CLT. BEEN WATCHING A LINE OF TSTMS COMING  
EAST ACROSS NORTHWEST GA LATE THIS MORNING. ENVIRONMENT AHEAD  
OF THIS LINE CONTINUES TO SLOWLY DESTABILIZE WITH EXTENSIVE  
LOW CLOUDINESS, BUT WE HAVE MANAGED TO DEVELOP 500-1000 J/KG OF  
SFC-BASED CAPE. FURTHER GRADUAL DESTABILIZATION SHOULD GET US INTO  
THE 1000-1500 RANGE, WHICH SHOULD BE ENOUGH FUEL TO KEEP THE LINE  
GOING AND PERHAPS SUPPORT SOME TRANSIENT SUPERCELL STRUCTURES GIVEN  
EXPECTED EFFECTIVE SHEAR OF 30-40KT THRU LATE AFTERNOON. THE CAMS  
DON'T SEEM SUPER-PUMPED ABOUT OUR CHANCES FOR A LOT OF SEVERE  
WEATHER, BUT CLEARLY THERE IS ORGANIZATION TO THE WEST AND THE  
ENVIRONMENT SHOULD BE SUFFICIENT TO SUSTAIN THE SEVERE WEATHER  
THREAT THRU THE AFTERNOON WEST-TO-EAST. NOTE THAT A FEW TORNADOES  
ARE STILL POSSIBLE, MAINLY IN THE VICINITY OF A WEAK REMNANT OUTFLOW  
BOUNDARY FROM THE MORNING CONVECTION THAT CAME ACROSS THE MTNS  
AND FIZZLED OVER THE NC FOOTHILLS. A FEW OF THE CAMS SHOW BRIEF  
ROTATING CORES MAINLY ONCE THE ACTIVITY GETS FARTHER EAST TOWARD  
THE CHARLOTTE METRO AREA. SLIGHTLY BETTER LOW LEVEL SHEAR/HELICITY  
IN THE VICINITY OF THIS REMNANT BOUNDARY COULD BE JUST ENOUGH TO  
SUPPORT A BRIEF TORNADO THREAT. OR, THIS COULD ALL STILL JUST REMAIN  
UNIMPRESSIVE SHOULD THE RENEWED SEVERE STORMS MOVING INTO WESTERN  
METRO ATL MANAGE TO RACE AHEAD AND CUT OFF OUR INFLOW. TEMPS HAVE  
BEEN ALTERED BY THE REMNANTS OF THE MORNING CONVECTION, SO SOME  
TWEAKS ARE IN ORDER, BUT HIGH TEMPS ARE UNCHANGED.  
 
OTHERWISE...A MATURE SFC LOW WILL TRACK ACROSS SOUTHERN  
ONTARIO/QUEBEC THRU THIS AFTERNOON, PULLING A COLD FRONT ACROSS  
THE OHIO VALLEY OVER THE COURSE OF THE DAY. AN MCS APPEARS LIKELY  
TO STRENGTHEN AND BE MAINTAINED ACROSS THE DEEP SOUTH, AND THIS IS  
BACKED UP BY CAM CONSENSUS SHOWING CONVECTION PROGRESSING ACROSS OUR  
SOUTHERN HALF IN MID TO LATE AFTERNOON. FURTHER NORTH INSTABILITY  
MAY BE MORE LIMITED, AND IN PARTICULAR SOME EARLIER HRRR RUNS SEEMED  
TO SUGGEST THE COLD POOL FROM THE DECAYED EARLY MORNING MCS WOULD  
HAVE A STABILIZING EFFECT IN THE NC MOUNTAINS/FOOTHILLS. DAMAGING  
WINDS--POSSIBLY FROM A LINEAR OR BOWING SEGMENT WITH EMBEDDED  
SUPERCELL STRUCTURES--WOULD BE THE PRIMARY THREAT TODAY,  
ALTHOUGH ENOUGH INSTABILITY WILL BE PRESENT FOR HAIL WITH ANY  
SUPERCELLS. LOW-LEVEL PARAMETERS SUPPORT A TORNADO THREAT AS WELL  
ALTHOUGH SOMEWHAT MORE MARGINAL. OF NOTE, MOST HRRR RUNS HAVE  
DEPICTED A ZONE OF STRONGER AND MORE PERSISTENT UPDRAFT HELICITY  
ALONG THE NORTHERN TIER OF SC AND ACROSS THE WESTERN PIEDMONT IN  
THE LATE AFTERNOON/EARLY EVE, MAYBE AS THE OLD OUTFLOW BOUNDARY  
ENCOUNTERED BY ROTATING ELEMENTS OF THE LINE MOVING EASTWARD.  
 
SOME SHOWERS APPEAR LIKELY TO REDEVELOP BEHIND THE PRIMARY LINE  
OF CONVECTION CLOSER TO THE SFC FRONT LATER IN THE AFTERNOON OR  
EVENING, BUT THE SEVERE THREAT WILL PROBABLY DROP OFF AFTER THE  
SOUTHERN LINE EXITS, MOST LIKELY BY 23Z. NW FLOW SHOWERS ALSO  
MAY DEVELOP ONCE WIND SHIFT OCCURS IN THE MOUNTAINS. TEMPS ARE  
EXPECTED TO REMAIN ABOVE FREEZING THERE, EXCEPT POSSIBLY IN THE  
HIGHEST ELEVATIONS AFTER PRECIP DIMINISHES NEAR DAYBREAK TUE. MINS  
WILL REMAIN A FEW DEGREES ABOVE NORMAL.  
 
 
   
SHORT TERM /TUESDAY THROUGH WEDNESDAY/  
 
KEY MESSAGES:  
 
1) DRY WEATHER RETURNS TUESDAY.  
 
2) A CHANCE OF SHOWERS AND ABOVE-NORMAL TEMPERATURES WEDNESDAY.  
 
AS OF 210 AM MONDAY: AN AXIS OF SFC HIGH PRES EXTENDING FROM  
ONTARIO WILL CROSS THE FORECAST AREA TUESDAY UNDER BUILDING HEIGHTS  
ALOFT. THE AIR MASS WILL BE FAIRLY DRY, WITH AFTN RH RETURNING  
TO THE 25-35% RANGE FOR MUCH OF THE AREA. TEMPS WILL BE ABOUT 5-8  
DEG ABOVE NORMAL WITH LIGHT WIND AND SUNNY SKIES.  
 
THE HIGH WILL SHIFT EAST TO QUEBEC AND NEW ENGLAND, WITH A  
WEDGE-LIKE RIDGE EXTENDING SOUTH INTO THE CAROLINAS TUESDAY NIGHT  
INTO WEDNESDAY. GUIDANCE AGREES THAT SOUTHERLY FLOW ATOP THE  
WEDGE MAY PRODUCE WIDESPREAD STRATUS BY DAYBREAK WEDNESDAY, WITH  
SOME ELEVATED INSTABILITY TO SUPPORT SCATTERED SHOWERS THRU THE  
DAY. THE HIGH WILL BE TRANSIENT, AND THE SHOWERY NATURE OF PRECIP  
SHOULD RESULT IN THE WEDGE STRUGGLING TO HOLD THRU THE DAY. WITH  
THAT SAID, THE 00Z GUIDANCE HAS TRENDED COOLER ON TEMPS, ESPECIALLY  
NEAR THE ESCARPMENT. THE NBM MAY BE STRUGGLING WITH THIS AND LOOKS  
A BIT TOO WARM. SO BLENDED IN THE CONSALL FOR HIGHS WEDNESDAY. THE  
ELEVATED CAPE MAY BE ENOUGH FOR ISOLATED GENERAL THUNDERSTORMS,  
ESPECIALLY NEAR THE WEDGE FRONT. THE FRONT WILL BEGIN TO LIFT NORTH  
AND MAY PRODUCE ADDITIONAL SHOWERS WEDNESDAY NIGHT. LOWS WILL BE  
SEVERAL DEG ABOVE NORMAL UNDER CLOUDY TO MOSTLY CLOUDY SKIES.  
 
 
   
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/  
 
KEY MESSAGES  
 
1) GENERALLY DRY WEATHER THRU SATURDAY, AS A STRONG RIDGE BUILDS  
ACROSS THE SOUTHEAST  
 
2) TEMPERATURES WARM TO NEAR RECORD HIGHS FRIDAY AND SATURDAY.  
 
3) RAIN CHANCES MAY RETURN SUNDAY WITH AN APPROACHING COLD FRONT.  
 
AS OF 250 AM MONDAY: A STRONG UPPER RIDGE WILL BUILD ACROSS  
THE SOUTHEAST THURSDSAY THRU SATURDAY, WITH A POTENTIAL 594 DAM  
RIDGE AT 500 MB JUST EAST OF FL. THIS RIDGE WILL KEEP A FRONT  
AND ASSOCIATED MOISTURE LARGELY WEST AN DNORTH OF THE FORECAST  
AREA DURING THIS PERIOD. HAVE OPTED TO GO WITH THE 6-HOURLY NBM  
POPS, WHICH ARE LOWER THAN THE REGULAR NBM, GIVEN THE EXPECTED  
SUPPRESSING EFFECTS OF THE HIGH. WITH THAT SAID, ENOUGH HUMIDITY  
MAY BE PRESENT FOR SOME DIURNAL INSTABILITY AND ISOLATED TO WIDELY  
SCATTERED SHOWERS THURSDAY, WITH THESE POPS BEING SHUNTED NORTH TO  
NEAR THE TN BORDER FRIDAY AND SATURDAY. HIGHS WILL LIKELY BE IN THE  
LOW TO MID 80S THURSDAY, AND MID TO UPPER 80S FRIDAY AND SATURDAY  
(POSSIBLY 90 AROUND CHARLOTTE). THESE WILL BE NEAR RECORD HIGHS  
FOR ALL THREE OF OUR CLIMATE SITES (SEE CLIMATE SECTION BELOW).  
 
IT MAY BE OPTIMISTIC, BUT THE 00Z GUIDANCE HAS COME IN SHOWING  
THE RIDGE BEGINNING TO BREAK DOWN SUNDAY, ALLOWING TEMPS TO NOT  
BE QUITE AS WARM AND ALSO BRINGING SOME RAIN CHANCES BACK INTO  
THE FORECAST AREA. A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE  
SOUTHERN GREAT LAKES AND MAY BRING A COLD FRONT THRU THE AREA  
SUNDAY OR SUNDAY NIGHT. POPS RAMP UP TO SOLID CHC TO LOW-END LIKELY.  
 
 
   
AVIATION /18Z MONDAY THROUGH SATURDAY/  
 
AT KCLT AND ELSEWHERE: MOSTLY IFR CIGS OVER THE PIEDMONT AT  
11Z. KAVL WILL SEE PREDOMINANTLY MVFR. AHEAD OF AN APPROACHING COLD  
FRONT, A LINE OF DECAYING TSRA WILL BE NEAR KAVL IN THE FIRST COUPLE  
HRS OF THE PERIOD AND SOME SHRA COULD SURVIVE TO KHKY. PROB30 AT  
KAVL AND VCSH AT KHKY FOR THIS ACTIVITY. CIGS WILL SLOWLY LIFT LATE  
MORNING TO MIDDAY. A SECOND BAND OF TSRA WILL DEVELOP IN AL/GA BY  
LATE MORNING AND WILL PROPAGATE INTO WESTERN NC/SC BY EARLY AFTN,  
PROMPTING TEMPOS AT ALL SITES FOR TSRA AND MVFR TO IFR VSBY/CIGS. A  
RISK OF DAMAGING WINDS AND POSSIBLY 1-2" HAIL WILL ACCOMPANY THESE  
STORMS. A FEW SHRA MAY REDEVELOP FOLLOWING THE TSRA WITH LESSER  
IMPACTS. WINDS WILL BE GUSTY 15-25 KT FROM THE SSW TO SW UNTIL EARLY  
EVENING, THEN SHIFT TO NW WITH PASSAGE OF FRONT. REDEVELOPMENT OF  
MVFR CIG CAN'T BE RULED OUT AT KAVL AFTER 06Z.  
 
OUTLOOK: DRYING AND VFR EXPECTED ON TUESDAY. SMALL CHANCE OF  
SHOWERS AND ASSOCIATED RESTRICTIONS WEDNESDAY AND THURSDAY.  
 
 
   
CLIMATE  
 
RECORDS FOR 04-03  
 
MAX TEMPERATURE MIN TEMPERATURE  
STATION HIGH LOW HIGH LOW  
------- ---------- ---------- ---------- ----------  
KAVL 88 1963 31 1936 64 1946 23 1936  
KCLT 90 1946 42 1915 62 1986 26 2021  
1946  
KGSP 87 1967 44 1901 62 2014 27 2021  
1963 1993  
1946 1902  
 
RECORDS FOR 04-04  
 
MAX TEMPERATURE MIN TEMPERATURE  
STATION HIGH LOW HIGH LOW  
------- ---------- ---------- ---------- ----------  
KAVL 83 1999 33 1891 61 1893 22 1936  
1978  
KCLT 87 1999 43 1911 63 1986 29 1936  
1899 1945  
1934  
KGSP 88 1963 44 1936 62 1999 25 1975  
1934  
 
RECORDS FOR 04-05  
 
MAX TEMPERATURE MIN TEMPERATURE  
STATION HIGH LOW HIGH LOW  
------- ---------- ---------- ---------- ----------  
KAVL 86 1909 30 1891 60 2023 20 1944  
1910  
KCLT 88 1942 38 1891 62 1910 26 1891  
KGSP 90 1934 43 1899 60 2023 25 1904  
1888  
 
RECORDS FOR 04-06  
 
MAX TEMPERATURE MIN TEMPERATURE  
STATION HIGH LOW HIGH LOW  
------- ---------- ---------- ---------- ----------  
KAVL 88 1967 36 1950 64 2023 22 1898  
KCLT 90 2010 43 1931 67 2023 28 1891  
1929  
KGSP 88 2010 47 1950 65 2023 26 1904  
1945  
 
 
   
GSP WATCHES/WARNINGS/ADVISORIES  
 
GA...NONE.  
NC...NONE.  
SC...NONE.  
 
 
 
 
 
SYNOPSIS...ARK  
NEAR TERM...PM/WIMBERLEY  
SHORT TERM...ARK  
LONG TERM...ARK  
AVIATION...WIMBERLEY  
CLIMATE...  
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