495
FXUS62 KGSP 230630
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
230 AM EDT THU JUL 23 2026
WHAT HAS CHANGED
RAIN TOTALS HAVE SLIGHTLY DECREASED THROUGH FRIDAY FOR THE NC
PIEDMONT.
SHOWER AND THUNDERSTORM CHANCES HAVE TRENDED DRIER FOR THE START OF
NEXT WEEK.
KEY MESSAGES
1. HEAVY RAINFALL AND POTENTIAL FLASH FLOODING THROUGH AT LEAST
FRIDAY. A FLOOD WATCH IS IN EFFECT THROUGH THURSDAY FOR MUCH OF
WESTERN NC.
2. A RETURN TO TYPICAL SUMMER WEATHER BEGINNING NEXT WEEK, WITH
HOT TEMPERATURES AND DAILY THUNDERSTORM CHANCES.
DISCUSSION
KEY MESSAGE 1: HEAVY RAINFALL AND POTENTIAL FLASH FLOODING THROUGH AT
LEAST FRIDAY. A FLOOD WATCH IS IN EFFECT THROUGH THURSDAY FOR MUCH
OF WESTERN NC.
A COMPLICATED SYSTEM CONTINUES TO EMERGE AS A BOUNDARY SLOWLY PUSHES
SOUTHWARD INTO THE CWA. AHEAD OF IT, ELEVATED PWATS OF 2"+ ARE
SETTING THE AREA UP FOR A POTENTIAL HEAVY RAIN EVENT. GUIDANCE HAS
THE BERMUDA HIGH TO THE EAST AND TS BERTHA TO THE SOUTHWEST IN LA
ALLOWING FOR A MOISTURE FETCH INTO THE REGION. HOWEVER, TS BERTHA IS
MUCH FURTHER WEST THAN MODEL GUIDANCE, REDUCING THE AMOUNT OF
MOISTURE STREAMING INTO THE AREA. OVERALL, THIS APPEARS TO BE A SLOW
MOVING SYSTEM THAT LOOKS TO REMAIN IN PLAY THROUGH AT LEAST FRIDAY.
SW WINDS APPEAR TO KICK IN A BIT OF A LOW LEVEL JET OVERNIGHT, WHICH
MAY AID IN FURTHER RAIN DEVELOPMENT, ESPECIALLY ALONG THE ESCARPMENT
AND INTO THE FOOTHILLS OF SC/NC. AT THIS TIME, GUIDANCE CONTINUES TO
HIGHLIGHT A SWATH OF 1-2" OF RAIN IN WESTERN NC AND INTO THE NC
PIEDMONT, WITH AN INCREASED CONCENTRATION THURSDAY. GIVEN ANY
INSTABILITY DRIVEN BY DAYTIME HEATING, CONVECTIVE RAINFALL RATES
COULD TICK THESE TOTALS UP IN ISOLATED LOCATIONS, INCREASING THE
RISK FOR FLASH FLOODING. THESE LOCALLY HIGHER AMOUNTS COULD RANGE
FROM 2-4". IT'S POSSIBLE THAT AS THE BOUNDARY CONTINUES TO SAG
SOUTH, RAINFALL TOTALS COULD INCREASE IN UPSTATE SC. A FLOOD WATCH
IS ALREADY IN EFFECT THROUGH 8 PM TONIGHT FOR WESTERN NC. AT THIS
TIME, WILL KEEP THE UPSTATE OUT OF A FLOOD WATCH AS CONFIDENCE IS
STILL NOT HIGH ENOUGH TO JUSTIFY ONE, YET. HOW MUCH RAIN DOES DEPEND
ON WHERE THE AXIS OF MOISTURE TRANSPORT SETS UP, WHICH IS HIGHLY
DEPENDENT ON WHERE THE BOUNDARY IS. IF THE BOUNDARY SLOWS AND
DOESN'T PUSH AS FAR SOUTH, THE MOISTURE PILING COULD OCCUR FURTHER
WEST. UPPER AIR SUPPORT IS ALSO NOT A GREAT FACTOR AS THE AREA OF
BETTER FORCING IS FURTHER EAST, OUTSIDE OF THE CWA. HOWEVER, IF THE
BOUNDARY DOES ADVANCE FURTHER SOUTH, IT COULD NARROW THE CORRIDOR OF
HEAVY RAINFALL TO THE WESTERN NC ZONES AND INTO THE UPSTATE THROUGH
FRIDAY, INCREASING THE RISK OF FLASH FLOODING. SO, ALL OF THIS TO
SAY THAT RAINFALL IS EXPECTED, BUT THERE STILL EXISTS UNCERTAINTY OF
WHERE THE HIGHER RAINFALL AMOUNTS COULD SETUP NOW THROUGH FRIDAY.
KEY MESSAGE 2: A RETURN TO TYPICAL SUMMER WEATHER BEGINNING NEXT
WEEK, WITH HOT TEMPERATURES AND DAILY THUNDERSTORM CHANCES.
A STRONG RIDGE CONTINUES TO BUILD AND REMAIN OVER THE WESTERN HALF
OF THE CONUS. BY SUNDAY, THE SOUTHEAST LOOKS TO REMAIN IN A MORE
TYPICAL JULY PATTERN WITH INCREASED TEMPERATURES AND DIURNALLY
DRIVEN SHOWERS AND THUNDERSTORMS. DAILY POP CHANCES RETURN TO 10-30%
WITHOUT ANYTHING BIG DRIVING THE POTENTIAL AFTERNOON CONVECTION.
TEMPERATURES ONCE AGAIN JUMP BACK INTO THE 90S AND HOT HEAT INDEX
VALUES RETURN.
AVIATION /06Z THURSDAY THROUGH MONDAY/
AT KCLT AND ELSEWHERE: SHOWERS CREATING RESTRICTIONS AS KHKY WITH
MVFR CIGS AT KAVL. EXPECT IFR CIGS TO EVENTUALLY DEVELOP AT BOTH
LOCATIONS WITH MVFR VSBY IN SHRA. ELSEWHERE, RESTRICTIONS AND SHOWERS
WILL BE SLOWER TO DEVELOP WITH MVFR BY DAYBREAK FOR ALL BUT KAND.
IFR DEVELOPS AT THE NC SITES THROUGH THE MORNING WITH IFR LATER IN
THE AFTERNOON OVER SC. SHOWER CHANCES INCREASE THROUGH THE DAY WITH
PROB30S FOR TSRA. SHOWERS AND TSRA CHANCE CONTINUES INTO THE EVENING
WITH IFR FOR MOST LOCATIONS. LOW END GUSTY SW WINDS TURN N THEN NE
THROUGH THE DAY AS A BOUNDARY SINKS SOUTH ACROSS THE AREA. WIND
REMAINS N AT KAVL THROUGH THE DAY.
OUTLOOK: RESTRICTIONS CONTINUE THROUGH SATURDAY AS SHOWERS AND
THUNDERSTORMS REMAIN. MUCH LOWER CHANCES OF CONVECTION AND
ASSOCIATED RESTRICTIONS SUNDAY AND MONDAY. LOW STRATUS AND/OR FOG
ARE POSSIBLE EACH MORNING IN THE MOUNTAIN VALLEYS AND LOCATIONS
WHICH RECEIVE HEAVY RAINFALL.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ033-035>037-048>053-
056>059-062>065-068>072-501>510.
SC...NONE.
CP/RWH
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