723
FXUS62 KGSP 051818
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
218 PM EDT SUN JUL 5 2026
WHAT HAS CHANGED
HIGH TEMPERATURES TRENDED SLIGHTLY COOLER FOR MONDAY AND TUESDAY.
HEAT INDEX / APPARENT TEMPERATURE HAS TRENDED 1 TO 2 DEGREES COOLER
FOR SUNDAY, MONDAY, AND TUESDAY.
UPDATED THE AVIATION DISCUSSION FOR THE 18Z TAFS.
KEY MESSAGES
1. HOT, HUMID CONDITIONS CONTINUE SUNDAY AND INTO THE NEW
WORKWEEK. THOSE WITH OUTDOOR PLANS SHOULD TAKE STEPS TO REMAIN
HYDRATED AND TAKE BREAKS INDOORS WHEN POSSIBLE. NEVER LEAVE
CHILDREN OR PETS UNATTENDED IN HOT VEHICLES.
2. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH AFTERNOON
THROUGH TUESDAY, WITH A LOW-END THREAT OF SEVERE WEATHER, MAINLY
DUE TO DAMAGING WINDS.
3. THE PATTERN BECOMES INCREASINGLY UNSETTLED THE LATTER HALF OF
THE WEEK, RESULTING IN MORE SHOWERS AND THUNDERSTORMS, BUT NOT
NECESSARILY CONFINED TO THE AFTERNOONS.
DISCUSSION
KEY MESSAGE 1: HOT, HUMID CONDITIONS CONTINUE SUNDAY AND INTO
THE NEW WORKWEEK. THOSE WITH OUTDOOR PLANS SHOULD TAKE STEPS TO
REMAIN HYDRATED AND TAKE BREAKS INDOORS WHEN POSSIBLE. NEVER LEAVE
CHILDREN OR PETS UNATTENDED IN HOT VEHICLES.
HOT AND MUGGY CONDITIONS ARE CONTINUE ACROSS THE WESTERN CAROLINAS
SUNDAY AFTERNOON, BUT SHOULD BE SOMEWHAT LESS PRONOUNCED TODAY THAN
THE PREVIOUS TWO DAYS. COMPETING EFFECTS ARE EXPECTED: GUIDANCE
BROADLY DEPICTS OVERALL LOWER LOW-LEVEL THICKNESS VALUES ACROSS
MOST OF THE AREA COMPARED TO THE LAST TWO DAYS, WITH THE CORE OF
SYNOPTIC-SCALE RIDGING NOW CENTERED TO OUR EAST; HOWEVER, SEVERAL
CAMS FEATURE A WEAK LEE TROUGH IN PLACE THROUGH THE AFTERNOON
(THERE'S ALREADY SOME EVIDENCE OF A LOW-LEVEL CONVERGENCE BAND
SETTING UP FROM PERHAPS THE SHELBY/RUTHERFORDTON AREA, NORTHEAST
UP TO I-40) WHICH COULD RESULT IN HIGHER DOWNSTREAM TEMPERATURES
OVER LOCALIZED PORTIONS OF THE NC PIEDMONT IN PARTICULAR.
THERE'S ALSO A BIG QUESTION MARK IN THE FORM OF AFTERNOON CONVECTION
(SEE KEY MESSAGE #2) TODAY, WHICH WOULD FURTHER DISRUPT AFTERNOON
HIGH TEMPERATURES.
ALL THINGS CONSIDERED, THE LIKELIHOOD OF HITTING TRUE HEAT ADVISORY
CRITERIA ACROSS MUCH OF OUR AREA IS PRETTY LOW FOR THIS AFTERNOON.
SO, NO PLANS TO ISSUE ONE WITH THE AFTERNOON FORECAST PACKAGE FOR
SUNDAY. HEAT AND HUMIDITY WILL CONTINUE EACH DAY THIS WEEK, BUT
GENERALLY LOOKS LIKE THE HIGHEST-IMPACT TEMPERATURES ARE OVER WITH.
FORECAST TEMPERATURES LOOK TO REMAIN ABOVE NORMAL BY A CATEGORY
OR TWO THROUGH THE WEEK (SO, MID-90S OUTSIDE THE MOUNTAINS) BUT
WITH HEAT INDEX VALUES STRUGGLING TO REACH INTO THE TRIPLE DIGITS.
KEY MESSAGE 2: SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH
AFTERNOON THROUGH TUESDAY, WITH A LOW-END THREAT OF SEVERE WEATHER,
MAINLY DUE TO DAMAGING WINDS.
PERSISTENT SUBTROPICAL RIDGING IS EXPECTED TO REMAIN IN PLACE FOR
MUCH OF THIS WEEK. GUIDANCE BROADLY AGREES THIS WILL KEEP UPPER
TROUGHING AND ANY ASSOCIATED SYNOPTIC-SCALE FORCING SHUNTED WELL
TO OUR NORTHWEST TODAY THROUGH TUESDAY, BEFORE THE PATTERN GETS A
LITTLE MORE PROGRESSIVE THE LATTER HALF OF THIS WEEK (SEE THIRD KEY
MESSAGE). THROUGH AT LEAST TUESDAY, WE'LL REMAIN WITHIN A MOISTURE-
RICH AIR MASS DIRECTLY EXPOSED TO THE GULF, WITH A FRONTAL ZONE
STALLED WELL TO OUR NORTH. MAINLY DIURNAL CONVECTION CAN BE
EXPECTED EACH AFTERNOON/EVENING. EACH DAY, INITIATION CAN GENERALLY
BE EXPECTED OVER THE NC MOUNTAINS, BUT CONFIDENCE ON CONVECTIVE
EVOLUTION REMAINS LIMITED AS IS TYPICAL ON THESE PULSE DAYS.
FOR SUNDAY, THERE LOOKS TO AGAIN BE A LOW-END SEVERE WEATHER RISK.
VEERING OF LOW- AND MID-LEVEL FLOW HAS RESULTED IN SOME IMPROVEMENT
OF 700-500MB RHS, AND A RESULTANT DECREASE IN DCAPE COMPARED
TO THE LAST FEW DAYS. SEEING SOME EVIDENCE OF A DEVELOPING LEE
TROUGH ALONG AND JUST EAST OF THE NC BLUE RIDGE ESCARPMENT...JUST
AS PREDICTED BY RECENT RUNS OF THE HRRR AND RRFS...AND IN ADDITION
TO THE TYPICAL RIDGETOP INITIATION, COULD SEE THE CONVERGENCE ZONE
AHEAD OF THE TROUGH SERVING AS A FOCUS FOR FURTHER INITIATION.
INDEED, MOST MEMBERS OF THE 12Z HREF DEPICT A LOOSELY-ORGANIZED
BAND OF SHOWERS AND THUNDERSTORMS PUSHING OUT OF THE MOUNTAINS BY
MID-AFTERNOON AND TRACKING EASTWARD ACROSS THE NC PIEDMONT AND
NORTHERN SC UPSTATE. THIS IS CLEARLY NOT SHEAR-DRIVEN (MOST OF
THE CAMS FEATURE A PALTRY 5-15KTS OF DEEP LAYER SHEAR), BUT RATHER
MAY BE FOCUSED BY THE LEE TROUGH INITIALLY, THEN OUTFLOW-DRIVEN
THEREAFTER. IN A 1500-2500 J/KG SBCAPE ENVIRONMENT, THOUGH, WE
CAN EXPECT SOME HEFTY UPDRAFTS, AND WITH EVEN A MARGINAL 600-800
J/KG SBCAPE, A LOW-END DAMAGING WIND THREAT IS WITHIN REASON.
AGREE WITH SPC'S MARGINAL RISK OF SEVERE WEATHER FOR TODAY.
THE CONVECTIVE SETUP LOOKS A LITTLE MORE SCRAMBLED ON MONDAY.
WE WON'T HAVE THE STRONG CROSS-BOUNDARY COMPONENT TO WINDS OVER THE
MOUNTAINS, AND WITHOUT THE PRESENCE OF A LEE TROUGH / CONVERGENCE
ZONE, THE CAMS DEPICT MORE RIDGE-DRIVEN INITIATION AND LOOK LESS
ORGANIZED OVERALL. DEEP LAYER SHEAR MAY BECOME MARGINALLY HIGHER
BY TUESDAY AFTERNOON, AS A COLD FRONT SETTLES ACROSS TENNESSEE
AND VIRGINIA, AND UPPER FLOW BECOMES ELEVATED BY AN APPROACHING
SHORTWAVE. VALUES OF 15-20KTS AS DEPICTED IN THE GFS, GDPS, AND
THEIR ENSEMBLES WOULD SUPPORT AT LEAST A MODICUM OF ORGANIZATION,
EVEN THOUGH ANY FRONTAL PASSAGE WILL LIKELY BE DELAYED UNTIL AT
LEAST EARLY WEDNESDAY MORNING.
KEY MESSAGE 3: THE PATTERN BECOMES INCREASINGLY UNSETTLED THE LATTER
HALF OF THE WEEK, RESULTING IN MORE SHOWERS AND THUNDERSTORMS,
BUT NOT NECESSARILY CONFINED TO THE AFTERNOONS.
THE PATTERN SHOULD BECOME MORE ACTIVE THE SECOND HALF OF NEXT WEEK.
SYNOPTIC GUIDANCE AGREES ON THE GRADUAL RETREAT OF SUBTROPICAL
RIDGING WEDNESDAY AND THURSDAY, WHICH SHOULD ALLOW US MORE
OPPORTUNITY FOR SOME SHORTWAVES TO MAKE IT INTO THE AREA. INDEED,
THE OPERATIONAL MODELS ALL FEATURE A FEW LOW-AMPLITUDE TROUGH
AXES CROSSING THE AREA DURING THE THURSDAY-SATURDAY TIMEFRAME.
CONFIDENCE REMAINS QUITE LOW ON TIMING AND DETAILS OF ANY SUCH
FEATURES, BUT IN GENERAL, WOULD EXPECT THE POTENTIAL FOR MORE
SYNOPTICALLY WELL-FORCED CONVECTION LATE IN THE WEEK, SHOULD UPPER
FEATURES ALIGN WELL WITH THE THERMODYNAMICS. THE ENVIRONMENT
DURING THIS PERIOD LOOKS LIKE IT'LL FEATURE BETTER SHEAR AS WELL,
SO THERE'S POTENTIAL FOR MORE ORGANIZED CONVECTION AS OPPOSED
TO THE TYPICAL SUMMERTIME PULSE CONVECTION WE'VE BEEN DEALING
WITH RECENTLY.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
AT KCLT AND ELSEWHERE: MOSTLY VFR CONDITIONS EXPECTED TO PREVAIL
THROUGH THE 18Z TAF PERIOD, EXCEPT WHERE THUNDERSTORMS DEVELOP
THIS AFTERNOON. ALREADY SEEING WIDESPREAD INITIATION CROSS THE
MOUNTAINS, AND TO A LESSER EXTENT, THE PIEDMONT AND UPSTATE.
EXPECT SCATTERED TO WIDESPREAD TSRA THROUGH MUCH OF THE AFTERNOON
AND EARLY EVENING...HANDLED BY A MIX OF TEMPOS AND PROB30S AT
ALL SIX TAF SITES...BEFORE COVERAGE WANES THROUGH THE EVENING.
OVERNIGHT, DRY CONDITIONS ARE STILL EXPECTED...AND SOME MOUNTAIN
VALLEY FOG COULD DEVELOP AGAIN, WITH SOME OF THE GUIDANCE HINTING
AT MVFR TO EVEN BRIEF IFR RESTRICTIONS AT KAVL. VFR SHOULD RETURN
AFTER SUNRISE MONDAY. ANOTHER ROUND OF CONVECTION IS EXPECTED
MONDAY AFTERNOON. WINDS SHOULD REMAIN SOUTHWEST THROUGH LATE
EVENING, BECOMING LIGHT AND VARIABLE OVERNIGHT, THEN PICKING UP
AGAIN OUT OF THE SOUTHWEST TOMORROW.
OUTLOOK: MAINLY AFTERNOON/EVENING SHOWER AND THUNDERSTORM CHANCES
WILL CONTINUE THROUGH AT LEAST TUESDAY. THE PATTERN REMAINS
UNSETTLED WEDNESDAY AND BEYOND, BUT CONFIDENCE IS LOWER ON HOW
THINGS WILL UNFOLD, AND WHAT THE CONVECTIVE POTENTIAL WILL BE.
LOW STRATUS AND/OR FOG WILL BE POSSIBLE EACH MORNING IN THE
MOUNTAIN VALLEYS AND IN LOCATIONS THAT SEE APPRECIABLE RAINFALL
THE PREVIOUS AFTERNOON/EVENING.
CLIMATE
RECORDS FOR 07-05
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 96 1948 71 1976 70 2024 46 1967
2018 1933
KCLT 101 2024 66 1892 78 2024 57 1967
KGSP 101 2024 70 1976 78 2016 58 1967
1933
1892
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
MPR
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