225
FXUS62 KGSP 230000
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
800 PM EDT FRI MAY 22 2026
WHAT HAS CHANGED
SMALL UPTICK IN SEVERE STORM AND FLOOD CHANCE THROUGH THIS EVENING
THEN AGAIN ON SATURDAY.
UPDATED THE AVIATION DISCUSSION FOR THE 00Z TAFS
KEY MESSAGES
1. COLD AIR DAMMING WILL MAINTAIN DREARY CONDITIONS FOR
MOST. WEDGE BOUNDARY ACROSS THE AREA COULD BECOME A FOCUS FOR
SEVERE THUNDERSTORMS. HEAVY RAINFALL EXPECTED TONIGHT WHICH MAY
LEAD TO FLOODING. COLD AIR DAMMING LINGERS INTO SATURDAY.
2. UNSETTLED WEATHER CONTINUES THROUGH MOST OF THE NEXT WEEK AS
THE LARGE-SCALE PATTERN USHERS GULF MOISTURE INTO THE CAROLINAS
AND NORTHEAST GEORGIA.
DISCUSSION
KEY MESSAGE 1: COLD AIR DAMMING WILL MAINTAIN DREARY CONDITIONS FOR
MOST. WEDGE BOUNDARY ACROSS THE AREA COULD BECOME A FOCUS FOR SEVERE
THUNDERSTORMS. HEAVY RAINFALL EXPECTED TONIGHT WHICH MAY LEAD TO
FLOODING. COLD AIR DAMMING LINGERS INTO SATURDAY.
THE WEDGE BOUNDARY IS QUITE OBVIOUS IN THE SURFACE OBS WITH WARM AND
MOIST CONDITIONS OVER THE UPPER SAVANNAH RIVER VALLEY AND THE
LAKELANDS. MUCH COOLER AND CLOUDY WITH STRONGER NE WINDS NORTH OF
THE BOUNDARY. SBCAPE ALSO SHOWS THIS BOUNDARY WITH A MODERATELY
UNSTABLE AIR MASS TO THE SOUTH DIMINISHING TO NON ACROSS MUCH OF THE
NC FOOTHILLS AND PIEDMONT. THAT SAID, EVEN IN THE WEDGE THERE IS
MUCAPE. EXPECT CONVECTION SPREAD ACROSS THE AREA THROUGH THE EVENING
AS A SHORT WAVE ROTATES INTO THE AREA. EVEN IN THE WEDGE, THUNDER
WILL OCCUR GIVEN THE MUCAPE. SPC HAS MOVED THE MARGINAL SEVERE RISK
INTO THE UPSTATE, WHICH MAKES SENSE GIVEN THE WEDGE BOUNDARY AND THE
INCREASED EFFECTIVE SHEAR DUE TO THE INSTABILITY. DAMAGING WIND IS
THE MAIN THREAT, BUT STORMS NEAR THE BOUNDARY WILL HAVE TO BE
MONITORED FOR A WEAK TORNADO SPIN UP.
THE SEVERE THREAT DIMINISHES THROUGH THE EVENING BUT HEAVY RAIN AND
THE FLOOD THREAT WILL INCREASE. HIGH PW VALUES, UPSLOPE FLOW, AND AN
INCREASING LOW LEVEL JET WILL LEAD TO SOME HEAVY RAINFALL,
ESPECIALLY OVER THE UPPER SAVANNAH RIVER VALLEY ACROSS THE BORDER
INTO THE NC SOUTHERN MOUNTAINS. DESPITE THE ONGOING DROUGHT
CONDITIONS, RAINFALL RATES IN THESE AREAS COULD BE ENOUGH FOR SOME
ISOLATED FLASH FLOODING TO DEVELOP. THE FLOOD THREAT TAPERS OFF
OVERNIGHT AS THE CONVECTION MOVES EAST.
THE COLD AIR DAMMING CONTINUES INTO SATURDAY WITH CLOUDY AND COOL
CONDITIONS ALONG WITH ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS.
WEAK INSTABILITY WITH SOME EFFECTIVE SHEAR CONTINUES, ESPECIALLY
ALONG AND SOUTH OF THE WEDGE BOUNDARY. THIS COULD LEAD TO SOME
STRONG TO SEVERE STORMS. RAINFALL RATES, WHILE NOT QUITE AS HIGH AS
TODAY, COULD BE HIGH ENOUGH FOR HEAVY RAINFALL AND ISOLATED
FLOODING. THE CONVECTION MOVES EAST THROUGH THE EVENING ENDING THE
SEVERE AND FLOOD THREAT.
KEY MESSAGE 2: UNSETTLED WEATHER CONTINUES THROUGH MOST OF THE NEXT
WEEK AS THE LARGE-SCALE PATTERN USHERS GULF MOISTURE INTO THE
CAROLINAS AND NORTHEAST GEORGIA.
SYNOPTIC GUIDANCE CONTINUES TO INDICATE THAT BROAD TROUGHING WILL
REMAIN IN PLACE ACROSS THE CENTRAL CONUS WHILE UPPER RIDGING WILL
STAY CENTERED OVER THE WESTERN ATLANTIC FROM SUNDAY THROUGH MUCH OF
NEXT WEEK. THIS CONFIGURATION IS FAVORABLE FOR STEADY MOISTURE FLUX
OFF THE GULF, MEANING MAINLY DIURNAL PERIODS OF GENERALLY WIDESPREAD
CONVECTION SHOULD CONTINUE.
WITH THE UNSETTLED WEATHER AND ABOVE-NORMAL RAINFALL CHANCES, IT IS
POSSIBLE THAT A LOW END HEAVY RAIN/FLOOD THREAT WILL CONTINUE, SO
WE'LL HAVE TO KEEP AN EYE ON THAT.
AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
AT KCLT AND ELSEWHERE: COLD AIR DAMMING REMAINS IN PLACE ACROSS
THE AREA, WITH MAINLY IFR CIGS AND MVFR VSBY WITH WIDESPREAD
LIGHT TO MODERATE SHOWERS. THERE IS A LINE OF TSTMS DRIFTING NE
ACROSS THE UPSTATE. THIS CONVECTION WILL RIDE OVER THE WEDGE AND
SHOULD WEAKEN, BUT THE LATEST HIGH-RES GUIDANCE DOES SHOW SOME
LINE REACHING ALL THE WAY TO KCLT LATER THIS EVENING INTO THE
OVERNIGHT. BEHIND THE LINE, ADDITIONAL SHOWERS WITH A FEW POSSIBLE
EMBEDDED TSTMS WILL REDEVELOP ACROSS THE AREA, ESPECIALLY ACROSS
THE MOUNTAINS. CIGS MAY LOWER TO LIFR OVERNIGHT WITHIN THE WEDGE,
THEN SHOULD IMPROVE SOMEWHAT DURING THE DAY SATURDAY, TO MVFR AT
KAND AND KCLT. ANOTHER ROUND OF DIURNAL CONVECTION IS EXPECTED,
AND WILL BE HANDLED WITH PROB30 GROUPS SATURDAY AFTN. WINDS WILL
CONTINUE IN THE USUAL CAD CONFIGURATION, WITH NE TO ENE ACROSS
THE PIEDMONT AND SSE AT KAVL. THE WEDGE FROM MAY LIFT NORTH AND
BRING WINDS OUT OF THE SE AT KCLT AND S AT KAND BY MIDDAY SATURDAY.
OUTLOOK: COLD-AIR DAMMING PERSISTS THRU SATURDAY NIGHT. THE CAD WILL
LIKELY PRODUCE WIDESPREAD MVFR TO IFR CEILINGS INTO SATURDAY NIGHT.
PERIODS OF MAINLY DIURNAL CONVECTION WILL ALSO CONTINUE ATOP THE CAD
WEDGE AND INTO NEXT WEEK, EVEN AS THE CAD ERODES. THE POTENTIAL FOR
OVERNIGHT FOG/LOW CLOUDS WILL INCREASE THROUGH THE PERIOD AS WELL.
ACTIVE DIURNAL CONVECTION EXPECTED TO CONTINUE THRU THE FIRST HALF
OF NEXT WEEK.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
ARK/RWH
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