119
FXUS62 KGSP 151808
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
208 PM EDT SUN MAR 15 2026
WHAT HAS CHANGED
CONFIDENCE IS HIGH THAT A LINE OF SEVERE THUNDERSTORMS WILL IMPACT
THE AREA EARLY MONDAY MORNING THROUGH EARLY MONDAY AFTERNOON.
A WIND ADVISORY HAS BEEN ISSUED FROM MONDAY AFTERNOON TO EARLY
TUESDAY MORNING FOR MOST MOUNTAIN LOCATIONS ABOVE 3,500 FEET.
SNOWFALL ACCUMULATIONS ON MONDAY INCREASED SLIGHTLY BUT REMAIN BELOW
WINTER WEATHER ADVISORY CRITERIA OUTSIDE OF THE HIGHEST ELEVATIONS.
KEY MESSAGES
1. SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM CONTINUE THIS
AFTERNOON THROUGH TONIGHT. A LINE OF SEVERE THUNDERSTORMS WILL THEN
CROSS THE AREA EARLY MONDAY MORNING THROUGH THE EARLY AFTERNOON
HOURS WITH A THREAT FOR DAMAGING WIND AND TORNADOES. MAKE SURE YOU
HAVE MULTIPLE WAYS TO RECEIVE WARNINGS AND THINK ABOUT WHERE YOU
WOULD SEEK SAFE SHELTER IF A WARNING WAS ISSUED FOR YOUR LOCATION.
2. PRECIPITATION WILL CHANGE TO SNOW ACROSS THE HIGHER MOUNTAIN
ELEVATIONS TOMORROW AFTERNOON WITH A BRIEF PERIOD OF NORTHWEST
FLOW SNOW THROUGH MONDAY NIGHT. GUSTY WINDS WILL DEVELOP BEHIND
THE COLD FRONT TOMORROW NIGHT THROUGH EARLY TUESDAY MORNING.
3. COLD AND DRY AIR RETURNS MONDAY NIGHT INTO WEDNESDAY NIGHT
WITH OVERNIGHT LOWS FALLING TO NEAR OR BELOW FREEZING. WARMER
TEMPERATURES RETURN THURSDAY INTO THE WEEKEND AND REMAINS DRY.
DISCUSSION
KEY MESSAGE 1: SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM
CONTINUE THIS AFTERNOON THROUGH TONIGHT. A LINE OF SEVERE
THUNDERSTORMS WILL THEN CROSS THE AREA EARLY MONDAY MORNING THROUGH
THE EARLY AFTERNOON HOURS WITH A THREAT FOR DAMAGING WIND AND
TORNADOES. MAKE SURE YOU HAVE MULTIPLE WAYS TO RECEIVE WARNINGS AND
THINK ABOUT WHERE YOU WOULD SEEK SAFE SHELTER IF A WARNING WAS
ISSUED FOR YOUR LOCATION.
A POTENT STORM SYSTEM CONTINUES TO EVOLVE TODAY AS AN INTENSE
PACIFIC JET DIVES THROUGH THE ROCKIES AND DIGS A HIGHLY ANOMALOUS
TROUGH ACROSS THE GREAT PLAINS. THE TROUGH WILL STRENGTHEN THROUGH
TONIGHT AS IT TAKES ON A NEGATIVE TILT AND LIFTS THROUGH THE
MISSISSIPPI VALLEY AND INTO THE APPALACHIANS. FARTHER NORTH, A
DEEPENING SURFACE LOW IS LIFTING THROUGH THE MIDWEST AND INTO THE
GREAT LAKES WITH THE LOW SITUATED BENEATH A COUPLED UPPER JET. THIS
WILL ALLOW FOR FURTHER DEEPENING WITH PRESSURES FORECAST TO FALL TO
NEAR 985MB. RESULTING LOW-LEVEL MASS RESPONSE WILL FOSTER ROBUST
WIND FIELDS THROUGH THE COLUMN WITH A VERY IMPRESSIVE 50KT LOW-LEVEL
JET TRANSLATING ACROSS THE REGION.
THROUGH THIS AFTERNOON, WELL IN ADVANCE OF THE APPROACHING COLD
FRONT, A PLUME OF DEEP MOISTURE RESIDING WITHIN AN INVERTED SURFACE
TROUGH EXTENDING FROM THE COASTAL PLAIN WILL PROMOTE THE DEVELOPMENT
OF A BATCH OF SHOWERS. THIS ACTIVITY WILL LIFT NORTH THROUGH THE
AFTERNOON AND INTO THIS EVENING ALONG WITH THE POTENTIAL FOR A FEW
EMBEDDED THUNDERSTORMS. AN ISOLATED SEVERE STORM CANNOT BE
COMPLETELY RULED OUT WITH SUFFICIENT DEEP-LAYER WIND SHEAR FOR
TRANSIENT SUPERCELL STRUCTURES ALONG WITH CYCLONICALLY CURVED
HODOGRAPHS OWING TO BACKED SOUTHEAST SURFACE FLOW. LOCALLY DAMAGING
WINDS AND A BRIEF TORNADO WILL BE POSSIBLE WITH ANY DEEPER STORMS,
BUT THE COVERAGE OF ANY SEVERE THREAT SHOULD REMAIN ISOLATED.
BY EARLY TOMORROW MORNING, STRONG HEIGHT FALLS WILL OVERSPREAD THE
SOUTHERN APPALACHIANS WITH A SURFACE COLD FRONT RACING TOWARDS THE
AREA. THE 12Z SUITE OF CAM GUIDANCE IS IN GOOD AGREEMENT THAT A LINE
OF SEVERE THUNDERSTORMS WILL RESIDE WITHIN A PREFRONTAL SURFACE
TROUGH AND WILL BE KNOCKING ON OUR DOOR BY ~4AM. THE LINE WILL PUSH
ACROSS THE AREA THROUGH THE MORNING HOURS BEFORE SHIFTING OFF TO THE
EAST BY EARLY AFTERNOON. STRONG MOISTURE ADVECTION WILL DRAW A PLUME
OF UPPER 50S TO LOW 60S DEWPOINTS INTO THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA. GIVEN COOL PROFILES ALOFT, THIS WILL BE
SUFFICIENT TO SUPPORT MODERATE BUOYANCY WITH 300-500 J/KG OF MLCAPE
DURING THE PRE-DAWN HOURS. VALUES INCREASE TO AROUND 1000 J/KG BY
MID TO LATE MORNING, MAINLY EAST OF I-26. WIND SHEAR WILL BE
PLENTIFUL WITH AROUND 60KTS OF 0-6KM DEEP-LAYER SHEAR AND 30-35KTS
OF 0-1KM SHEAR ALONG WITH 200-300 M2/S2 OF 0-1KM SRH. THE
THERMODYNAMIC AND KINEMATIC ENVIRONMENT IN CONCERT WITH INTENSE
SYNOPTIC FORCING SHOULD SUPPORT MAINTENANCE OF THE LINE OF SEVERE
THUNDERSTORMS THROUGH THE AREA. THE MAIN THREATS WILL BE FOR
DAMAGING STRAIGHT LINE WINDS ALONG WITH THE POTENTIAL FOR LINE
EMBEDDED TORNADOES, ESPECIALLY WITH ANY NORTHEAST SURGING LINE
SEGMENTS OR LINE BREAKS.
KEY MESSAGE 2: PRECIPITATION WILL CHANGE TO SNOW ACROSS THE HIGHER
MOUNTAIN ELEVATIONS TOMORROW AFTERNOON WITH A BRIEF PERIOD OF
NORTHWEST FLOW SNOW THROUGH MONDAY NIGHT. GUSTY WINDS WILL DEVELOP
BEHIND THE COLD FRONT TOMORROW NIGHT THROUGH EARLY TUESDAY MORNING.
STRONG COLD ADVECTION BEHIND THE FRONT WILL LIKELY CHANGE TRAILING
SHOWERS OVER TO SNOW ACROSS THE HIGHER MOUNTAIN ELEVATIONS TOMORROW
AFTERNOON. A BRIEF PERIOD OF NORTHWEST FLOW SNOW SHOWERS WILL ALSO
CONTINUE THROUGH MONDAY NIGHT BEFORE TAPERING OFF EARLY TUESDAY
MORNING. GENERALLY LIGHT ACCUMULATIONS OF SNOW WILL BE POSSIBLE
ABOVE 3500 FT WITH THE HIGHEST TOTALS OF 4-6" EXPECTED ACROSS THE
HIGHEST ELEVATIONS OF THE SMOKIES. WINDS ACROSS THE HIGH TERRAIN
WILL ALSO BE QUITE GUSTY IN THE POST FRONTAL COLD ADVECTION REGIME.
GUSTS WILL PEAK TOMORROW AFTERNOON INTO EARLY TUESDAY MORNING WITH
FREQUENT GUSTS OF 50-60MPH EXPECTED ABOVE 3500 FT. A WIND ADVISORY
HAS BEEN HOISTED FOR MOST OF THE MOUNTAINS ALONG THE TENNESSEE
BORDER THROUGH 5AM TUESDAY. OVERNIGHT LOWS TUESDAY MORNING WILL BE
QUITE COLD COMPARED TO THE WARM START TO MARCH. LOWS ARE FORECAST TO
FALL INTO THE TEENS ACROSS THE MOUNTAINS WITH MID TO UPPER 20S
OUTSIDE THE MOUNTAINS. THESE TEMPERATURES COMBINED WITH GUSTY WINDS
WILL RESULT IN RATHER UNPLEASANT WIND CHILLS FOLLOWING WELL ABOVE
NORMAL WARMTH TO START THE MONTH.
KEY MESSAGE 3: COLD AND DRY AIR RETURNS MONDAY NIGHT INTO WEDNESDAY
NIGHT WITH OVERNIGHT LOWS FALLING TO NEAR OR BELOW FREEZING. WARMER
TEMPERATURES RETURN THURSDAY INTO THE WEEKEND AND REMAINS DRY.
BEHIND THE STRONG COLD FRONT, SURFACE HIGH PRESSURE BUILDS INTO THE
SOUTHEAST. ALONG WITH THE DRIER CONDITIONS, MUCH COLDER AIR RETURNS
MONDAY NIGHT THROUGH AT LEAST WEDNESDAY NIGHT. OVERNIGHT LOWS ARE
EXPECTED TO REACH FREEZING AND BELOW, WITH TUESDAY NIGHT LOOKING TO
BE THE COLDEST. THE LATEST NBM PROBABILITIES FOR BELOW-FREEZING LOW
TEMPERATURES ARE 70-80 PERCENT IN THE SOUTHERN AND EASTERN PIEDMONT
AND 100 PERCENT ELSEWHERE ACROSS THE AREA FOR MONDAY NIGHT, AND
NEARLY 100 PERCENT ACROSS THE ENTIRE AREA TUESDAY NIGHT. THE
DETERMINISTIC FORECAST ADVERTISES WIDESPREAD TEENS AND LOW 20S FOR
THE MOUNTAINS AND 20S ELSEWHERE. BY WEDNESDAY, THE AIR MASS STARTS
TO MODIFY AS MOISTURE STARTS TO RETURN WITH WINDS VEERING MORE
SOUTHERLY. TEMPS WEDNESDAY NIGHT SHOULD WARM A TICK AND BE CLOSER TO
FREEZING WITH A FEW LOCATIONS AT THE HIGHER ELEVATIONS CONFIDENTLY
REMAINING WELL BELOW FREEZING. THIS IS REFLECTED IN THE NBM
PROBABILITIES FOR SUB-FREEZING TEMPERATURES WEDNESDAY NIGHT WHICH
WERE 30-50 PERCENT IN THE CITIES, 50-60 PERCENT IN THE PIEDMONT AND
FOOTHILLS, AND 60-80 PERCENT IN THE MOUNTAINS (EXCEPT HIGHER AT
ELEVATIONS ABOVE 4 KFT). SENSITIVE PLANTS THAT HAVE ALREADY BLOOMED
FROM THE RECENT ABNORMALLY WARM WEATHER WILL BE PARTICULARLY
VULNERABLE TO THESE COLD TEMPERATURES EACH NIGHT. TEMPERATURES
INCREASE STEADILY THURSDAY AND THROUGH THE WEEKEND. DRY CONDITIONS
DOMINATE AFTER TUESDAY ONWARD.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
AT KCLT AND ELSEWHERE: A MIX OF MVFR AND VFR CONDITIONS CONTINUES
ACROSS MUCH OF THE AREA AS MOISTURE STREAMS BACK INTO THE REGION.
THIS WILL CONTINUE TO BE THE CASE THROUGH MUCH OF THE AFTERNOON AND
THROUGH THE OVERNIGHT HOURS. SHOWERS WILL ALSO LIFT NORTH THROUGH
THE AFTERNOON AND INTO THE EVENING AND COULD RESULT IN TEMPORARY
VISIBILITY RESTRICTIONS. MVFR CEILINGS SHOULD BECOME MORE WIDESPREAD
TONIGHT WITH A FEW INSTANCES OF IFR NOT OUT OF THE QUESTION ALONG
WITH LINGERING ISOLATED TO WIDELY SCATTERED SHOWERS. THE MAIN FOCUS
WILL SHIFT TO A LINE OF SEVERE THUNDERSTORMS THAT IS FORECAST TO
PUSH ACROSS THE AREA THROUGH THE MORNING HOURS. THIS WILL IMPACT ALL
TERMINALS WITH STRONG WINDS AND HEAVY RAIN AS IT MOVES THROUGH.
WINDS WILL INCREASE OVERNIGHT AHEAD OF THE FRONT WITH GUSTS
CONTINUING THROUGH THE NED OF THE TAF PERIOD BEHIND THE FRONT AS
WELL. VFR SHOULD BEGIN TO RETURN BY THE VERY END OF THE TAF PERIOD.
OUTLOOK: GUSTS SUBSIDE ON TUESDAY AND COME TO AN END BY WEDNESDAY
WITH VFR THROUGH THURSDAY.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...WIND ADVISORY FROM 4 PM MONDAY TO 5 AM EDT TUESDAY FOR NCZ033-
048>053-059-063-064.
SC...NONE.
CP/JK/TW
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