060
FXUS62 KGSP 291055
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
655 AM EDT SAT MAR 29 2025
SYNOPSIS
SOUTHERLY FLOW AROUND HIGH PRESSURE CENTERED OFF THE EAST COAST
WILL BRING INCREASING MOISTURE AND ABOVE NORMAL TEMPERATURES TO
THE REGION. SHOWER AND THUNDERSTORM CHANCES INCREASE SUNDAY INTO
MONDAY AS A COLD FRONT CROSSES THE AREA. DRY HIGH PRESSURE RETURNS
TUESDAY, FOLLOWED BY ANOTHER APPROACHING FRONT MID-WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 650 AM: STRONG WESTERN ATLANTIC HIGH PRESSURE NOSING INTO
THE SOUTHEAST CONUS. DEEP SHORTWAVE CENTERED OVER THE ARKLATEX IS
ASSOCIATED WITH PLENTIFUL HIGH ALTITUDE MOISTURE AND WILL PROVIDE
SOME DPVA AS IT TRACKS NORTHEAST INTO KY/TN TODAY, ALTHOUGH
DAMPENING. LIGHT TO MODERATE LOW LEVEL SOUTHERLY FLOW CONTINUES
OVER OUR CWA THIS MORNING. BEGINNING TO SEE SOME LOW STRATUS SHOULD
DEVELOP ALONG THE SOUTH-FACING BLUE RIDGE ESCARPMENT ON SFC OBS
AND OCCASIONALLY SATELLITE, WHEN CIRRUS BREAK. A FEW HIGH BASED
RETURNS ON RADAR BUT PRECIP UNLIKELY EXCEPT PERHAPS FOR A LITTLE
DRIZZLE. FORCING WITH THE SHORTWAVE LOOKS TO ARRIVE LATER IN THE
DAY WHEN SOME OF THE LOW-LEVEL MOISTURE WILL HAVE HAD A CHANCE TO
MIX OUT. THERE IS SOME PROGGED SBCAPE BUT THE VERY DRY MIDLEVEL AIR
SEEN ABOVE THE PBL APPEARS TO BE TOO MUCH OF A LIMITING FACTOR FOR
UPDRAFTS: CAMS CONTINUE TO FEATURE VERY LITTLE QPF RESPONSE. A SMALL
AREA OF SLIGHT-CHANCE POP WILL BE RETAINED OVER THE SW NC RIDGES
AND THE WESTERN ESCARPMENT. THE BETTER THERMODYNAMICS WILL BE WEST
OF OUR MOUNTAINS IN TN. LIKEWISE, THE SOUTHERLY FLOW SHOULD CARRY
ANY CELLS DEVELOPING IN THE SMOKIES INTO TN IF THEY CAN SURVIVE
THAT LONG. INCREASED THICKNESSES ARE LIKELY TO BE OFFSET BY CLOUD
COVER TODAY; MAX TEMPS END UP ABOUT THE SAME AS FRIDAY IN OUR EAST,
AND A COUPLE DEGREES COOLER IN THE CLOUDIER WEST HALF.
SYNOPTIC SCALE WARM FRONT APPEARS TO LIFT NORTH INTO THE CWA
TONIGHT IN CONJUNCTION WITH STRENGTHENING LOW PRESSURE IN THE
MIDWEST. LOW-LEVEL FLOW WILL TURN A BIT MORE SOUTHWESTERLY, BUT
MECHANICAL LIFT STILL SHOULD BE PRESENT ALONG THE ESCARPMENT
AND ALSO IN THE SW-FACING RIDGES. MIDLEVEL MOISTURE INCREASES
AND SATURATION SHOULD OCCUR THRU A MUCH DEEPER LAYER, MAINLY
AFTER MIDNIGHT. CAM RESPONSE DOES REMAIN MAINLY ALONG THE
TERRAIN. POPS INCREASE FIRST IN THAT AREA AND THEN EXPAND INTO
THE LOWER ELEVATIONS IN THE SAVANNAH VALLEY, WESTERN UPSTATE,
AND EASTERN NC FOOTHILLS CLOSER TO DAWN SUNDAY. WIDESPREAD LOW
CLOUDS ARE LIKELY TO DEVELOP BY SUNDAY MORNING ALSO. MIN TEMPS
10-15 ABOVE NORMAL UNDER THESE CONDITIONS; HIGH-MIN RECORDS STILL
ARE UNLIKELY TO BE THREATENED.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
KEY MESSAGES:
1) SHOWERS AND THUNDERSTORM CHANCE INCREASE SUNDAY THROUGH MONDAY.
2) STRONG TO SEVERE THUNDERSTORMS POSSIBLE MONDAY WITH A COLD
FRONT MOVING INTO THE AREA.
AS OF 300 AM SATURDAY: GUIDANCE IS IN GOOD AGREEMENT ON UNSETTLED
WEATHER FOR SUNDAY THRU MONDAY, AS MOISTURE INCREASES WITHIN
A PERSISTENT SOUTHERLY TO SOUTHWESTERLY FLOW. ISENTROPIC AND
MECHANICAL LIFT WITH SOME ELEVATED CAPE SHOULD RESULT IN SCATTERED
TO NUMEROUS SHOWERS DURING THE DAY SUNDAY, WITH BEST CHANCES IN
THE S- AND SW-FACING SLOPES OF THE MOUNTAINS. FORCING DOESN'T LOOK
SUPPORTIVE OF HEAVY RAINFALL OR STRONG STORMS. BUT A FEW DOWNPOURS
AND LIGHTNING STRIKES WILL BE POSSIBLE IN THE DEEPEST CONVECTION. A
RELATIVE LULL IN POPS IS INDICATED IN THE GUIDANCE SUNDAY NIGHT,
AS ISENTROPIC LIFT WEAKENS. POPS THEN SHOULD PICK UP AGAIN FROM
WEST TO EAST, AS A COLD FRONT APPROACHES FROM THE OH/TN VALLEY. THE
FRONT SHOULD PRODUCE DECENT FORCING, AND THE TIMING STILL LOOKS TO
BE DURING THE PEAK-AFTN/EARLY-EVENING HOURS. THE 00Z GUIDANCE HAS
TRENDED DOWN SLIGHTLY ON THE SBCAPE, BUT STILL A FEW HUNDRED J/KG
COMBINED WITH 0-6 KM BULK SHEAR OF 40-50 KT WOULD SUPPORT STRONG TO
SEVERE STORMS. SOME CURVATURE IN HODOGRAPHS AND MODEL REFLECTIVITY
SUGGESTING SOME DISCRETE CELLS HINT AT SOME SUPERCELLS AND TORNADO
THREAT ALONG WITH THE PRIMARY DAMAGING WIND THREAT. THE FRONT AND
ASSOCIATED CONVECTION SHOULD PASS THRU TO THE EAST BY AROUND 06Z
TUESDAY. TEMPS WILL BE 10-15 DEG ABOVE NORMAL SUNDAY THRU MONDAY,
THEN FALL TO NEAR NORMAL BEHIND THE FRONT MONDAY NIGHT.
LONG TERM /TUESDAY THROUGH FRIDAY/
KEY MESSAGES
1) DRY WEATHER RETURNS TUESDAY WITH RAIN CHANCES INCREASING
BY MIDWEEK.
2) TEMPERATURES WILL WARM TO WELL ABOVE NORMAL LATE IN THE WEEK.
AS OF 320 AM SATURDAY: TUESDAY LOOKS LIKE A RETURN TO NEAR NORMAL
TEMPS AND LOW HUMIDITY, WITH AFTN RH DIPPING INTO THE 30-40%
RANGE. HOPEFULLY, SUNDAY-MONDAY'S RAINFALL AND EXPECTED LIGHT WINDS
TUESDAY WILL LIMIT FIRE WEATHER CONCERNS. THE PATTERN WILL THEN
AMPLIFY THE REST OF THE WEEK, WITH A STOUT 500 MB HIGH BUILDING
OVER THE SOUTHEAST. A SFC HIGH WILL ESTABLISH ITSELF OVER THE
WESTERN ATLANTIC, PUMPING UP THICKNESSES OVER THE REGION. THE 00Z
DETERMINISTIC MODELS DISAGREE ON HOW AMPLIFIED THE RIDGE WILL BE,
WITH THE GFS A LITTLE FLATTER AND ALLOWING A FRONT TO SAG SOUTH
TOWARD THE AREA THURSDAY. THE EC AND CANADIAN SHOW A STRONGER HIGH
AND GENERALLY DRIER WEATHER FOR THE FORECAST AREA. EITHER WAY,
TEMPS WILL BE 10-15 DEG ABOVE NORMAL THURSDAY AND POSSIBLY 15-20
DEG ABOVE NORMAL FRIDAY (MID 80S ACROSS THE PIEDMONT). THE LATEST
NBM POPS RAMP UP INTO THE CHANCE RANGE THURSDAY, BUT THESE MAY BE
OVERDONE IF THE MODELS TREND STRONGER WITH THE RIDGE.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
AT KCLT AND ELSEWHERE: VFR AT THE TERMINALS THRU AT LEAST SUNSET,
POSSIBLY EXCEPTING KAVL. A BRIEF RESTRICTION WILL BE POSSIBLE
THERE DUE TO SMOKE FROM WILDFIRES SSW OF THE FIELD NEAR THE SC
BORDER. MOST LIKELY TIME WOULD BE THIS AFTERNOON, BUT WITH LOW
CONFIDENCE ON TIMING/DURATION NO MENTION IS MADE IN TAF. ABUNDANT
HIGH ALTITUDE CLOUDS ABOVE FL150 WILL BE SEEN AROUND THE REGION
TODAY WITH SHORTWAVE OVER THE DEEP SOUTH. MECHANICAL LIFT WITHIN
INCREASINGLY MOIST SOUTHERLY FLOW WILL BRING MVFR LEVEL CLOUDS TO
SOME MOUNTAIN AREAS SW OF KAVL BUT NOT LIKELY AFFECTING ANY TAF
TERMINAL; LIKEWISE ISOLATED SHRA COULD DEVELOP IN THE FAR WESTERN NC
MOUNTAINS AND ADVECT INTO TN AND OUT OF THE AREA. SOUTHERLY WINDS
PICK UP AFTER DAYBREAK WITH 15-20 KT GUSTS THIS AFTN. TONIGHT,
THE MECHANICAL LIFT WILL PERSIST, AND WITH DEEPENING MOISTURE MORE
WIDESPREAD MVFR TO IFR CLOUDS WILL DEVELOP, AT KAVL PERHAPS AS SOON
AS 06Z BUT MORE LIKELY TO AFFECT THE TERMINALS AFTER 09Z. PROB30 FOR
LIGHT PRECIP DEVELOPMENT BEFORE 12Z SUN AT KAVL AND THE SC SITES,
AND AFTER 12Z AT KCLT, WITH ATTENDANT RISK OF IFR.
OUTLOOK: RESTRICTIONS AND PRECIP CONTINUE TO DEVELOP SUNDAY
WITH RESTRICTIONS LINGERING SUNDAY NIGHT. SHRA/TSRA POSSIBLE
MONDAY. DRYING IS EXPECTED FOR TUE, LIKELY LASTING INTO WED.
FIRE WEATHER
ALTHOUGH MIXING THIS AFTERNOON WILL TAP INTO A DRY LAYER ABOVE THE
PBL AND DEWPOINTS THUS DIP DIURNALLY, SOUTHERLY FLOW IS PROVIDING
ENOUGH MOISTURE RETURN THIS MORNING THAT RH WILL REMAIN ABOVE 30% IN
ALL AREAS, AND PROBABLY CLOSER TO 50% IN THE HIGHER ELEVATION AREAS
WHERE WILDFIRES ARE ALREADY BEING FOUGHT. THAT SAID, PER
COORDINATION WITH NC STATE OFFICIALS, AN IMPACT-BASED FIRE DANGER
STATEMENT IS CURRENTLY IN PLACE FOR NC ON ACCOUNT OF THE CRITICALLY
DRY FUELS. WIND GUSTS OF 20-25 MPH, BRIEFLY UP TO 30 MPH, WILL BE
POSSIBLE AGAIN THIS AFTERNOON.
PRECIP ACTIVITY THROUGH THIS EVENING IS NOT LIKELY TO HAVE A
SIGNIFICANT IMPACT ON ONGOING WILDFIRES. HOWEVER, CHANCES INCREASE
TOWARD DAYBREAK SUNDAY, WITH THE FASTEST ACCUMULATION RATES LIKELY
TO OCCUR SUNDAY.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...INCREASED FIRE DANGER FROM NOON EDT TODAY THROUGH THIS EVENING
FOR NCZ033-035>037-048>053-056>059-062>065-068>072-082-
501>510.
SC...NONE.
SYNOPSIS...ARK
NEAR TERM...WIMBERLEY
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...WIMBERLEY
FIRE WEATHER...WIMBERLEY
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