303
AWUS01 KWNH 110908
FFGMPD
VAZ000-NCZ000-WVZ000-SCZ000-111500-
MESOSCALE PRECIPITATION DISCUSSION 1477
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
507 AM EDT SUN OCT 11 2026
AREAS AFFECTED...BLUE RIDGE OF VIRGINIA, NORTH CAROLINA AND
NORTHERN SOUTH CAROLINA...
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY
VALID 110910Z - 111500Z
SUMMARY...PROLONGED SOLID MOISTURE FLUX INTO TERRAIN WITH
OCCASIONAL LOCALIZED SOUTH TO NORTH MOVING CONVECTIVE ELEMENTS
ENHANCING RATES TO 1"+/HR TO ADD ADDITIONAL 1-2" WITH LOCALIZED 3"
SPOTS ALONG BLUE RIDGE. FLOODING LIKELY TO CONTINUE AND EXPAND IN
COVERAGE NORTHWARD WITH TIME.
DISCUSSION...IMPRESSIVE GOES-E WV SUITE SHOWS SHORTWAVE ALONG
EASTERN SIDE HAS ROTATED NORTH TO RECENTER THE DEEPER MID-LEVEL
CYCLONE OVER CENTRAL KY. THIS IS LIFTING THE CENTER OF ISAIAS
NORTHWARD INTO THE CUMBERLAND PLATEAU WHILE ALSO ADVANCING THE
COLD FRONT OUT OF GA INTO THE UPSTATE OF SC. STATIONARY FRONT
REMAINS NEAR THE SC/NC BORDER AND IS SUPPORTING ACTIVE STRONG
CONVECTION THOUGH THE GULF STREAM. THE COMBINATION IS HELPING TO
MAINTAIN A SOLID LOW TO MID-LEVEL GRADIENT WITH COOL CONVEYOR BELT
STILL FLUXING ENHANCED MOISTURE NORTH OF THE FRONT WESTWARD INTO
THE TERRAIN. CIRA LVT VALUES ARE WEAKENING SLIGHTLY BUT REMAIN
ABOVE 150 KG/M/S ACROSS CENTRAL VA GIVEN .75-.8" ADVECTED ON
30-40KTS CENTERED AROUND 925MB. ALOFT, THE WARM CONVEYOR BELT IS
BROADENING AND SHIFTING AXIS TOWARD THE GULF STREAM AND 850-500
LPW LAYERS HAVE SEEN A SLOW DECREASE; STILL 35-45KTS OF VEERING
SOUTHWEST TO SOUTHERLY FLOW IS STARTING TO INTERSECT THE TERRAIN A
BIT MORE OBLIQUELY THAN EARLIER THIS MORNING AND LVT VALUES ARE
MORE AROUND 100-150 KG AND NARROWING TOWARD THE WESTERN BRANCH OF
THE WCB, JUST IN ADVANCE OF THE COLD FRONT. AS SUCH, OROGRAPHIC
ASCENT WILL SUPPORT A THIRD TO HALF INCH PER HOUR, ALLOWING FOR A
BROAD AREA OF 1-2" ACROSS THE EASTERN SLOPES OF THE CENTRAL
APPALACHIANS AS THE TRIPLE POINT LIFTS NORTHEASTWARD.
INSTABILITY WEDGE REMAINS ABOUT 500-1000 J/KG ACROSS SC, BUT IS
NARROWING AS WELL GIVEN LIMITED NORTHWARD SURGE OF THE EFFECTIVE
WARM FRONT; CONVERGENCE AHEAD OF THE FRONT IS STILL SPURRING
CONVECTIVE DEVELOPMENT BUT IT REMAINS MORE SCATTERED AND LESS
VIGOROUS, CONTINUOUS AS BEFORE. STILL GIVEN AMPLE MOISTURE, RATES
OF 1-1.25"/HR REMAIN POSSIBLE ACROSS UPSTATE SC INTO THE FOOTHILLS
OF W NC AND FAR SW VA. SPOTS OF ADDITIONAL 2-3" ARE POSSIBLE BUT
MORE LIKELY TO BE ISOLATED TO WIDELY SCATTERED IN NATURE. GIVEN
FFG VALUES ACROSS FAR UPSTATE SC AND W NC (LESS THAN .75" FOR ALL
HOURS) ARE SIGNIFICANTLY COMPROMISED, EVEN THE REMAINING SHOWERS
ARE LIKELY TO MAINTAIN FLASH FLOODING/BROADER RIVERINE FLOODING
THIS MORNING. AS THE TROWAL CORRIDOR SHIFTS EASTWARD INTERSECTING
INTO SW VA, FFG VALUES HAVE REDUCED TO LESS THAN 1" FOR MOST HOURS
AS WELL AND EXCEEDANCE IS PROBABLE. HOWEVER, FURTHER NORTH INTO
CENTRAL WESTERN VA, OVERALL TOTALS REMAIN BELOW 2" FOR THE STORM
AND ADDITIONAL 1-3" WOULD BRING SOME SPOTS CLOSER TO FFG VALUES
BUT POTENTIAL ARE LESS LIKELY THAN FURTHER SOUTHWESTWARD ALONG THE
BLUE RIDGE RANGE.
GALLINA
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...GSP...LWX...RAH...RNK...
ATTN...RFC...ALR...ORN...RHA...TIR...NWC...
LAT...LON 39007830 38767815 38127848 37027946 35778017
34768167 35028243 35458258 36228168 36778112
37058078 37777996 38467915 38827883
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