835
FXUS62 KGSP 291731
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
131 PM EDT FRI AUG 29 2025
SYNOPSIS
HIGH PRESSURE REMAINS BEFORE A WEAK COLD FRONT CROSSES THE AREA
SATURDAY, KEEPING THE COOLER WEATHER IN PLACE. A BRIEF SHOWER OR
THUNDERSTORM POSSIBLE EACH DAY ACROSS THE MOUNTAINS. TEMPERATURES
REMAIN BELOW SEASONAL NORMALS THROUGH THE WEEK.
NEAR TERM /THROUGH SATURDAY/
AS OF 130 PM FRIDAY: ANOMALOUS UPPER TROUGH WILL REMAIN CENTERED
OVER THE REGION THROUGH THE NEAR TERM, REINFORCED BY A SERIES
OF SPEED MAXIMA DIGGING SOUTHEAST FROM THE UPPER MISS VALLEY
AND THE OHIO VALLEY TONIGHT. THESE HEIGHT FALLS ARE FORECAST TO
RESULT IN WEAK ACTIVATION OF THE QUASI-STATIONARY BAROCLINIC ZONE
OVER THE SOUTHEAST LATE TONIGHT INTO SATURDAY. BY FAR THE HIGHEST
ASSOCIATED PRECIP CHANCES ACROSS THE REGION WILL BE SOUTH OF OUR
FORECAST AREA, BUT ENOUGH OF A SIGNAL EXISTS TO ADVERTISE SMALL
POPS ACROSS SOUTHERN AREAS THROUGHOUT THE DAY. FARTHER NORTH OF
THERE...DECENT INSOLATION AND STEADILY INCREASING LOW LEVEL MOISTURE
IS EXPECTED TO RESULT IN MODEST DESTABILIZATION SAT AFTERNOON,
WITH INCREASED POTENTIAL FOR DIURNAL CONVECTION (MAINLY SHOWERS)
ACROSS THE MOUNTAINS. EVEN SO, POPS ARE 30% AT MOST. OTHERWISE,
QUIET CONDITIONS TONIGHT WITH ANOTHER ROUND OF FOG/LOW STRATUS
LIKELY IN THE VALLEYS OF THE NC COUNTIES BORDERING TN. MIN TEMPS
ARE EXPECTED TO REMAIN A FEW DEGREES BELOW CLIMO. MAXES SATURDAY
ARE EXPECTED TO RANGE FROM 5+ DEGREES BELOW NORMAL UNDER THICKER
CLOUD COVER ACROSS THE LAKELANDS AND VICINITY...TO SLIGHTLY BELOW
NORMAL ACROSS MUCH OF WESTERN NC.
SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/
AS OF 125 PM EDT FRIDAY: PICKING UP ON SATURDAY NIGHT, A PERSISTENT
RIDGE OUT WEST AND TROUGH OVER THE EASTERN CONUS REMAIN THE DOMINANT
SYNOPTIC FEATURE DRIVING THE COOLER WEATHER ACROSS THE CWA. A STRONG
UPPER LOW OVER CANADA LIFTS NORTHWARD WHILE THE TROUGH SPLITS AS
HIGH PRESSURE FORMS OVER THE UPPER MIDWEST. GUIDANCE TRIES TO SPIN A
CUTOFF LOW THAT SETS UP OVER THE MID-ATLANTIC BY SUNDAY NIGHT.
MEANWHILE, GUIDANCE INCREASES MOISTURE A BIT THROUGH THE PERIOD, BUT
NOTHING QUITE AS MISERABLE AS THE PAST FEW SUMMER MONTHS. A FEW
SHORTWAVES COME THROUGH AND WITH THE UPTICK IN PWATS, INCREASES RAIN
CHANCES, ESPECIALLY ACROSS THE MOUNTAINS. CURRENT POPS AT THE HIGHER
PEAKS ARE IN THE CHANCE RANGE (50-65%) WITH SLIGHT CHANCE (15-30%)
FOR THE REST OF THE MOUNTAINS AND PORTIONS ELSEWHERE. FOR SUNDAY,
UPPER AIR GUIDANCE SHOWS SOME ELEVATED AND SURFACE BASED INSTABILITY
DURING THE AFTERNOON HOURS, SO CANNOT RULE OUT A RUMBLE OF THUNDER.
PROBABILITY OF THUNDER FOR SUNDAY IS HOVERING AROUND SLIGHT CHANCE
(15-30%). TEMPERATURES START TO TREND COOLER INTO THE BEGINNING OF
THE WEEK.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
AS OF 130 PM EDT FRIDAY: THE PATTERN REMAINS RELATIVELY QUIET
THROUGH THE EXTENDED. BY MONDAY NIGHT, THE FLOW ALOFT BECOMES MORE
BROAD. AT THE SURFACE, GUIDANCE SLOWLY INCREASES THE MOISTURE IN THE
SOUTHERN ZONES, BUT KEEPS IT MODEST. LONG RANGE GUIDANCE DOES HAVE A
STRONG SIGNAL FOR YET ANOTHER UPPER LOW DEVELOPING OVER CANADA WITH
A STRENGTHENING TROUGH DIGGING ACROSS THE EASTERN CONUS. THIS IS
EXPECTED TO CONTINUE THE COOLING TREND AS WINDS BECOME NW AND DRIER
AIR FILTERS IN. THERE COULD ALSO BE A MIDWEEK COLD FRONT THAT PASSES
THROUGH AS WELL AS A FEW SHORTWAVES WITH THE NW SETUP. DAILY PRECIP
CHANCES (20-45%), ESPECIALLY ACROSS THE MOUNTAINS. WINDS COULD
BECOME A BIT GUSTIER, DEPENDING ON HOW FAR SOUTH THE TROUGH DIGS AND
HOW TIGHT THE PRESSURE GRADIENT BECOMES. NOTHING TOO CONCERNING AT
THIS TIME AND WILL CONTINUE TO MONITOR. TEMPERATURES REMAIN JUST
BELOW AVERAGE DURING THE EXTENDED PERIOD.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
AT KCLT AND ELSEWHERE: OTHER THAN THE EXPECTED REDEVELOPMENT
OF EARLY MORNING MOUNTAIN VALLEY FOG/LOW STRATUS IN AREAS TO
THE WEST AND NORTH OF KAVL, VFR CONDITIONS ARE EXPECTED THROUGH
TOMORROW. SOME CU/STRATOCU IN THE 050-070 RANGE IS EXPECTED TO
DEVELOP LATER TODAY, CONTINUING OFF AND ON THROUGH TONIGHT. SOME
SPOTTY SHOWERS WILL BE POSSIBLE ACROSS THE MOUNTAINS AND SOUTHERN
PORTION OF THE TERMINAL FORECAST AREA DURING THE DAYLIGHT HOURS
SATURDAY, BUT THE CHANCES ARE TOO LOW FOR A TAF MENTION AT THIS
TIME. WINDS ARE GENERALLY EXPECTED TO BE LIGHT (EXCEPT FOR 5-10
KTS AT KAVL), WITH DIRECTION MOSTLY FAVORING A NORTHERLY COMPONENT
THROUGH THE PERIOD.
OUTLOOK: SCATTERED AFTERNOON, MAINLY MOUNTAIN SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO RETURN EARLY IN THE NEW WEEK AND
CONTINUE THROUGH AT LEAST THE MIDDLE OF THE WEEK. FOG AND/OR
LOW STRATUS MAY DEVELOP EACH NIGHT/EARLY MORNING, MAINLY IN THE
MOUNTAIN VALLEYS.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...CP
NEAR TERM...JDL
SHORT TERM...CP
LONG TERM...CP
AVIATION...JDL
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