099
FXUS62 KGSP 170607
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
207 AM EDT SAT OCT 17 2026
WHAT HAS CHANGED
LOW TEMPERATURE TONIGHT HAS BEEN LOWERED BY ANOTHER FEW DEGREES. THE
FREEZE WATCH HAS BEEN UPGRADED TO A FREEZE WARNING. TO THE EAST
OF THE WARNING, A FROST ADVISORY HAS BEEN ISSUED FROM EXTREME
NORTHEAST GEORGIA, ACROSS THE UPPER FRENCH BROAD VALLEY, AND
EXTENDING ACROSS THE NORTHERN FOOTHILLS OF NORTH CAROLINA.
KEY MESSAGES
1. IN THE WAKE OF A STRONG COLD FRONT, TEMPERATURES WILL BE
MUCH COOLER ACROSS THE AREA THROUGH THE WEEKEND. MUCH OF THE NC
MOUNTAINS WILL DROP DOWN BELOW FREEZING TONIGHT AND WIDESPREAD
FROST IS EXPECTED IN EXTREME NORTHEAST GA, THE UPPER FRENCH BROAD
VALLEY, AND THE NC FOOTHILLS.
DISCUSSION
KEY MESSAGE 1: IN THE WAKE OF A STRONG COLD FRONT, TEMPERATURES WILL
BE MUCH COOLER ACROSS THE AREA THROUGH THE WEEKEND. MUCH OF THE
NC MOUNTAINS WILL DROP DOWN BELOW FREEZING TONIGHT AND WIDESPREAD
FROST IS EXPECTED IN EXTREME NORTHEAST GA, THE UPPER FRENCH BROAD
VALLEY, AND THE NC FOOTHILLS.
NOW THAT A STRONG COLD FRONT HAS MOVED EAST OF THE FCST AREA EARLY
THIS MORNING, THE COOL-DOWN WILL COMMENCE BY DAYBREAK. A FEW SHORT
LINEAR SEGMENTS OF SHOWERS WERE NOTED ON RADAR, WITH ADDITIONAL
LIGHT RAIN UPSTREAM CLOSER TO THE DPVA ASSOCIATED WITH THE MAIN
UPPER SHORT WAVE APPROACHING FROM THE WEST. THE GUIDANCE SHOWS A
BROAD BAND OF LIGHT PRECIP DEVELOPING OVER THE EAST SIDE OF THE
FCST AREA IN THE PRE-DAWN HOURS AS FORCING IMPROVES WITH THE WAVE
PASSAGE, MAINLY IN THE FORM OF LOW LEVEL ISENTROPIC UPGLIDE. MUCH OF
THIS LIGHT SHOWER ACTIVITY WILL BE ALONG/EAST OF I-77 AT DAYBREAK,
AND MUCH OF THE CLOUDINESS WILL DEPART TO THE EAST SHORTLY
THEREAFTER. HIGH PRESSURE WILL BUILD IN FROM THE NW AND N THROUGH
THE DAY AFTER THE UPPER WAVE MOVES AWAY TO THE EAST. INDICATIONS
ARE CONSISTENT THAT HIGH TEMPS WILL BE 20 DEGREES OR SO COOLER
THAN YESTERDAY IN SPITE OF PLENTY OF SUN THIS AFTERNOON.
THE MAIN CONCERN COMES TONIGHT AS THE PRESSURE GRADIENT RELAXES
AND SKY CLEARS OUT. EVEN THOUGH THE HIGH CENTER REMAINS WELL
TO OUR NORTH, RADIATIONAL COOLING SHOULD BE EFFECTIVE ENOUGH TO
ALLOW TEMPS TO DROP DOWN AT OR BELOW FREEZING ACROSS MOST OF THE
MOUNTAINS. THE DOWNWARD CREEP OF LOW TEMPS CONTINUES AGAIN THIS
CYCLE. THE CONSENSUS WAS TO LOWER THE LOW TEMPS TONIGHT BELOW WHAT
IS SEEN IN THE NBM, WHICH TRACKS BECAUSE WE OFTEN UNDERESTIMATE
THE COLD AIR IN THESE EARLY AUTUMN EVENTS. THUS, THE FREEZE WATCH
WILL BE UPGRADED TO A FREEZE WARNING. TO THE EAST OF THE WARNING,
FROST LOOKS LIKE A GOOD BET AWAY FROM THE THERMAL BELTS, SO A
FROST ADVISORY WILL BE ADDED.
BEYOND THAT, THE UPPER PATTERN GRINDS TO A HALT AS THE STRONG
UPPER WAVE CLOSES OFF AN UPPER LOW THAT SHOULD MOVE ACROSS THE
MID-ATLANTIC REGION TODAY AND THEN SET UP SHOP OFF THE EASTERN
SEABOARD THROUGH THE MIDDLE OF NEXT WEEK. MODIFICATION OF THE AIR
MASS ALLOWS FOR TEMPS TO REBOUND BY 3-5 DEGREES THE NEXT FEW DAYS TO
THE POINT WE SHOULD BE BACK TO NORMAL BY TUESDAY OR WEDNESDAY. NO
PRECIP IS EXPECTED. SOME FROST/FREEZE CONCERNS ARE POSSIBLE AGAIN
SUNDAY NIGHT, BUT TEMPS WILL NOT BE QUITE AS COLD. WE WILL WAIT AND
SEE HOW WE FARE TONIGHT BEFORE ACTING ON ANY ADDITIONAL ADVISORIES.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
AT KCLT AND ELSEWHERE: GUSTY NNW TO NNE WINDS EXPECTED OVERNIGHT
THRU THE MORNING, PEAKING DURING THE AFTN HOURS ACROSS THE
AREA. GUSTS HAVE BEEN LESS FREQUENT ACROSS THE UPSTATE, BUT A
GAP WIND IS EXPECTED TO AFFECT KGMU/KGSP DURING THE PRE-DAWN
HOURS. LOW-TO-MID VFR CLOUDS WILL CROSS THE AREA THRU MID-
MORNING, WITH GUIDANCE IN DECENT AGREEMENT ON A BAND OF LIGHT
RAIN SHOWERS DEVELOPING OVER MAINLY THE NC PIEDMONT AND EASTERN
SC PIEDMONT ROUGHLY IN THE 08Z-14Z TIME FRAME. KCLT HAS THE
HIGHEST CHANCE OF SOME -RA, BUT IT SHOULD BE GENERALLY TOO LIGHT
TO PRODUCE ANYTHING MORE THAN SOME MVFR CIGS. GUIDANCE HAS
OVERALL BACKED OFF THE MVFR CIGS THIS MORNING FOR KCLT, AND EVEN
AT KAVL TO SOME EXTENT. STILL EXPECT A FEW HOURS OF MVFR CIGS
AT KAVL, BUT I'VE BUMPED THEM UP TO 3500 FT AT KCLT. VFR CIGS
WILL GRADUALLY CLEAR OUT THIS AFTN, WITH SKC EXPECTED THIS
EVENING. WINDS WILL ALSO START TO DIMINISH AND LOSE GUSTINESS
THIS EVENING.
OUTLOOK: BREEZY NE WINDS EXPECTED AGAIN ACROSS THE PIEDMONT SUNDAY
AFTN. OTHERWISE, DRY, VFR CONDITIONS EXPECTED FOR MOST OF NEXT
WEEK. MTN VALLEY FOG AND LOW STRATUS WILL BE POSSIBLE EACH MORNING.
GSP WATCHES/WARNINGS/ADVISORIES
GA...FROST ADVISORY FROM 1 AM TO 9 AM EDT SUNDAY FOR GAZ010-017.
NC...FROST ADVISORY FROM 1 AM TO 9 AM EDT SUNDAY FOR NCZ035-064-065-
501>507-509.
FREEZE WARNING FROM 1 AM TO 9 AM EDT SUNDAY FOR NCZ033-048>053-
058-059-062-063.
SC...FROST ADVISORY FROM 1 AM TO 9 AM EDT SUNDAY FOR SCZ101>103.
ARK/PM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page