154
FXUS62 KGSP 161808
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
208 PM EDT SAT MAY 16 2026
WHAT HAS CHANGED
RAIN CHANCES TRENDING HIGHER THURSDAY INTO SATURDAY, WITH RAINFALL
AMOUNTS TRENDING HIGHER, ESPECIALLY ON THURSDAY.
TRENDING COOLER FOR FRIDAY.
KEY MESSAGES
1. A SUMMER-LIKE PATTERN WILL BE IN PLACE THROUGH MID-WEEK,
WITH ABOVE NORMAL TEMPERATURES, INCREASING HUMIDITY, AND SPOTTY
DIURNAL CONVECTION EXPECTED.
2. A COLD FRONT BRINGS BETTER RAIN CHANCES MID TO LATE WEEK BUT
WITH RAINFALL AMOUNTS EXPECTED TO REMAIN LIGHT, ANY DROUGHT RELIEF
WILL BE LIMITED. WELL ABOVE NORMAL HIGHS LINGER THROUGH THURSDAY
BEFORE COLD AIR DAMMING LEADS TO THE RETURN OF BELOW NORMAL HIGHS
FRIDAY INTO SATURDAY.
DISCUSSION
KEY MESSAGE 1: A SUMMER-LIKE PATTERN WILL BE IN PLACE THROUGH
MID-WEEK, WITH ABOVE NORMAL TEMPERATURES, INCREASING HUMIDITY,
AND SPOTTY DIURNAL CONVECTION EXPECTED.
A BERMUDA HIGH WILL PERSIST AND GRADUALLY EXPAND/INTENSIFY ACROSS
THE WESTERN ATLANTIC THROUGH MID-WEEK AS AN UPPER RIDGE BUILDS
STRONGLY ALONG THE EAST COAST. RESULTANT LOW-LEVEL TRAJECTORIES OFF
THE EASTERN GULF WILL SUPPORT STEADILY INCREASING MOISTURE ACROSS
OUR FORECAST AREA THROUGH SUNDAY, WITH SURFACE DEWPOINTS IN THE
UPPER 50S/LOWER 60S EXPECTED DURING THE AFTERNOON. MEANWHILE, AN
EXPANSIVE ELEVATED MIXED LAYER WILL CONTINUE TO COVER MUCH OF THE
EASTERN HALF OF THE COUNTRY THROUGH SUNDAY, WITH MID-LEVEL LAPSE
RATES OF AROUND 8 C/KM FORECAST ACROSS THE SOUTHEAST. THAT BEING THE
CASE, STRONG INSOLATION (MAX TEMPS 6-9 DEGREES ABOVE CLIMO; ABOUT 5
DEGREES WARMER THAN TODAY) IS RESULTING IN FORECAST SOUNDINGS
DEPICTING SURFACE-BASED CAPE OF AROUND 2000 J/KG DESPITE THE
SOMEWHAT MODEST DEWPOINTS SUNDAY AFTERNOON. ON THE OTHER HAND, THERE
IS A DECENT CAPPING INVERSION AT THE TOP OF THE RELATIVELY MOIST
BOUNDARY LAYER. IN LIGHT OF ANY ORGANIZED AREAS OF UPWARD VERTICAL
MOTION, INITIATION OF DEEP CONVECTION WILL THEREFORE BE A BIT OF A
TALL ORDER ACROSS THE CWA SUNDAY AFTERNOON, BUT WILL BE MOST LIKELY
ACROSS THE FAR WEST. ADDITIONALLY, CONVECTION COULD INITIATE
UPSTREAM ACROSS CENTRAL GA...WHERE THE CAP IS FORECAST TO BE
WEAKER...AND WANDER INTO THE WESTERN ZONES BY LATE AFTERNOON/EARLY
EVENING. 20-30 POPS WILL BE CARRIED ACROSS ~THE WESTERN THIRD OF THE
AREA DURING THIS TIME FRAME. WIND SHEAR WILL BE PRACTICALLY NON-
EXISTENT, BUT A FEW STRONG UPDRAFTS PULSES CAN'T BE RULED OUT GIVEN
THE DEGREE OF BUOYANCY.
MID-LEVEL LAPSE RATES WILL BEGIN TO STEADILY MODIFY SUNDAY NIGHT
INTO MONDAY, AS TEMPS WARM ALOFT IN ASSOCIATION WITH THE BUILDING
UPPER RIDGE. NEVERTHELESS, WITH DEWPOINTS CONTINUING TO STEADILY
INCREASE, FORECAST SOUNDINGS SUGGEST SUFFICIENT INSTABILITY TO
WARRANT SMALL POPS ACROSS THE FAR WESTERN MOUNTAINS DURING THE
AFTERNOON. AS TIME PROGRESSES TOWARD MID-WEEK, LOW LEVEL
TRAJECTORIES ARE EXPECTED TO BECOME MORE ORIENTED OFF THE WESTERN
ATLANTIC AS THE BERMUDA HIGH EXPANDS...SUCH THAT LOWER THETA-E AIR
ORIGINATING FROM THE SUBSIDENT REGION WITHIN THE ANTICYCLONE WILL
ADVECT INTO THE AREA...LOWERING SURFACE DEWPOINTS/INCREASING
STABILITY AS THE MID-LEVELS CONTINUE TO WARM. DIURNAL CONVECTION
THEREFORE IS NOT EXPECTED TUESDAY. TEMPERATURES WILL OTHERWISE
REMAIN STEADY AT 6-9 DEGREES ABOVE NORMAL THROUGH TUE NIGHT.
KEY MESSAGE 2: A COLD FRONT BRINGS BETTER RAIN CHANCES MID TO LATE
WEEK BUT WITH RAINFALL AMOUNTS EXPECTED TO REMAIN LIGHT, ANY DROUGHT
RELIEF WILL BE LIMITED. WELL ABOVE NORMAL HIGHS LINGER THROUGH
THURSDAY BEFORE COLD AIR DAMMING LEADS TO THE RETURN OF BELOW NORMAL
HIGHS FRIDAY INTO SATURDAY.
THE BERMUDA HIGH REMAINS IN CONTROL OF THE PATTERN ON WEDNESDAY
AHEAD OF AN APPROACHING COLD FRONT. THIS WILL ACT TO KEEP HOT AND
WELL ABOVE NORMAL TEMPERATURES AROUND, ESPECIALLY EAST OF THE
MOUNTAINS, AS WELL AS KEEPING AROUND DIURNAL SHOWER AND THUNDERSTORM
ACTIVITY. THE FRONT TRACKS ACROSS THE FORECAST AREA THURSDAY BEFORE
STALLING OVER THE DEEP SOUTH AND COASTAL CAROLINAS FRIDAY INTO
SATURDAY, BRINGING BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS.
ALTHOUGH NBM POPS AND QPF ARE TRENDING A BIT HIGHER COMPARED TO THE
PREVIOUS FORECAST, RAINFALL AMOUNTS STILL LOOK TO REMAIN BELOW AN
INCH ACROSS MOST LOCATIONS THURSDAY THROUGH SATURDAY. A FEW LUCKY
LOCATIONS COULD SEE RAINFALL AMOUNTS GREATER THAN 1" BUT THIS SHOULD
BE LOCALIZED. WILL CONTINUE TO MONITOR QPF TRENDS CLOSELY IN THE
COMING DAYS BUT FOR NOW IT APPEARS THERE WILL BE LIMITED RELIEF FROM
THE DROUGHT WITH THIS FRONT. COLD AIR DAMMING DEVELOPS BEHIND THE
FRONT AS HIGH PRESSURE BUILDS IN FROM THE NORTH THURSDAY NIGHT INTO
FRIDAY, WITH THE WEDGE EXPECTED TO LINGER THROUGH AT LEAST SATURDAY.
CAD WILL ACT TO LIMIT THE SEVERE POTENTIAL AS WELL AS ALLOW FOR THE
RETURN OF BELOW NORMAL HIGH TEMPERATURES. THE NBM HAS TRENDED MUCH
LOWER COMPARED TO THIS TIME YESTERDAY REGARDING FRIDAY'S HIGHS SO
EXPECT THIS TREND TO CONTINUE IN THE NEXT SEVERAL FORECAST CYCLES,
WITH THIS TREND ALSO POSSIBLE FOR SATURDAY AS THE WEDGE REMAINS
LOCKED IN PLACE.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
AT KCLT AND ELSEWHERE: VFR IS FORECAST TO PERSIST ACROSS THE
TERMINAL FORECAST AREA THROUGH THE PERIOD, WITH MAINLY INCREASING
HIGH CLOUDS ANTICIPATED THROUGH TONIGHT. HAVING SAID THAT, GUIDANCE
SOURCES ARE SIGNALING SOME POTENTIAL FOR LOW CLOUDS TO DRIFT
INTO THE PIEDMONT FROM THE SOUTH AND SOUTHWEST TOWARD DAYBREAK
SUNDAY. CONFIDENCE IN THIS REMAINS VERY LOW AT THIS JUNCTURE,
AND LOW CLOUDS WILL NOT BE REFLECTED IN THE FORECAST. SW WINDS OF
6-10 KTS THIS AFTERNOON WILL BECOME LIGHT THIS EVENING...INCREASING
FROM THE SW AT 4-7 KTS BY EARLY SUNDAY AFTERNOON.
OUTLOOK: VFR CONDITIONS EXPECTED TO PERSIST THROUGH MID-WEEK,
EXCEPT IN MOUNTAIN VALLEYS, WHERE THERE WILL BE SOME POTENTIAL FOR
MORNING FOG/LOW STRATUS, ESPECIALLY EARLY IN THE WEEK. ISOLATED
DIURNAL CONVECTION IS POSSIBLE SUNDAY AND MONDAY AFTERNOONS,
PRIMARILY ACROSS THE MOUNTAINS, AND PERHAPS NEAR KAND. AN ACTIVE
COLD FRONT MAY BRING RESTRICTIONS ASSOCIATED WITH CONVECTIVE PRECIP
BY LATE WEEK.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
AR/JDL
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