MESOSCALE PRECIPITATION DISCUSSION 0728
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
229 AM EDT SAT OCT 08 2016
 
AREAS AFFECTED...SOUTHERN NC...EASTERN SC...EXT SOUTHEAST GA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 080630Z - 081230Z
 
SUMMARY...ADDITIONAL 4-10" RAINFALL ALONG COASTAL COUNTIES OF
SC/EXT S NC WITH BROADER MODERATE 1-4" TOTALS ACROSS ACROSS
CENTRAL SC INTO CENTRAL NC OVER THE NEXT 6HRS EXPANDING AREAL
COVERAGE OF FLOODING THREAT.  

DISCUSSION...CURRENT SYNOPTIC SETUP SHOWS INFLUENCE OF SWLY SHEAR
AND EXPANDING WEST/NORTHERN OUTFLOW CHANNEL STARTING TO CHANGE THE
SHAPE OF MATTHEW IN THE COMING HOURS.  SURFACE ANALYSIS, GOES-EAST
3.9UM SWIR AND 89GHZ MOSAIC PRESENTS A STATIONARY FRONT FROM THAT
HUGS THE COAST FROM NEAR CHS TO ILM BEFORE AN INFLECTION POINT
JUST SOUTH OF CAPE HATTERAS EXTENDS ESE INTO THE ATLANTIC TOWARD
NORTHERN OUTER BANDS OF NICOLE.  ANALYSIS ALSO INDICATES N-S
BANDING FEATURE ALONG 79W THAT BENDS BACK TOWARD CHS.  RAP
ANALYSIS INDICATES VERY MOIST BUT ALSO QUITE UNSTABLE ENVIRONMENT
BETWEEN THESE FEATURES WITH CAPES IN EXCESS OF 2000 J/KG...THIS
MST FLUX/ENERGY IS BEING TRANSPORTED ACROSS THE SFC STATIONARY
FRONT ALONG THE COAST PROVIDING STRONG ASCENT AND EFFICIENT
RAINFALL PRODUCTION.  OVER THE NEXT 6HRS...FRONT WILL REMAIN
FAIRLY STATIONARY BEING ENFORCED BY STRONG E AND NELY FLOW ACROSS
THE ATLANTIC...WHILE THE NORTHEASTERN BANDS OF MATTHEW WILL DEEPLY
CONVECT WHILE ALSO MERGE/CONVERGE WITH TIME...FOCUSING TOWARD THE
NE SC AND EXT S NC COASTLINE WITH RATES UPWARD OF 2.5-3"/HR
POSSIBLE VERY NEAR THE COAST...EVENTUALLY WEAKENING INTO MODERATE
SHIELD PRECIPITATION ACROSS THE I-95 CORRIDOR AS FAR EAST OF
COLUMBIA SC.

FARTHER SOUTH...VERY STRONG CONVECTION ON NW SIDE OF DEVOLVING
EYEWALL FEATURE SUPPORTS CONTINUED PRESSURE FALLS FURTHER WEST
HOLDING SHORT-TERM MOTIONS DUE NORTH...THIS SHOULD BRING INNER
EYEWALL VERY NEAR OR OVER HILTON HEAD/EDISTO ISLAND IN THE NEXT
FEW HOURS...WITH EXTREME RAINFALL RATES UP TO 3"+ PROBABLE. WITH
INCREASING SW SHEAR AND EXCELLENT OUTFLOW CHANNEL TO THE
NW/N...EXPECT A NARROWING WEDGE SHAPE TO THE CDO FEATURE TAKING ON
MORE OF AN BAROCLINIC LEAF/OCCLUDED SHAPE IN IR/RADAR MOSAIC AS
THE MID/UPPER LEVEL CIRCULATION BECOMES INCREASINGLY DECOUPLED
WITH THE SFC LOW WHICH SHOULD CONTINUE TO HUG THE COAST. THIS WILL
LEAVE AREAS THAT HAVE SEEN 3" NEAR LAKE MARION TO 9-10" FROM SVN
TO NBC TO RECEIVE AN ADDITIONAL 4-7" COMPOUNDING ONGOING LIFE
THREATENING FLOODING IN THE REGION.  

HI-RES CAMS SHOW REMARKABLE AGREEMENT PROVIDING HIGHER CONFIDENCE
IN THESE RAINFALL MAGNITUDES...EVOLUTION FAVORING THE HRRR/ESRL
HRRR AND NSSL-WRF AND NMMB...WHICH SHOW THE TIGHTER GRADIENT OF
TOTALS FAVORING THE AREAS ALONG THE COAST AND JUST DOWNSTREAM OF
THE FRONTAL ZONE. 

GALLINA

ATTN...WFO...CAE...CHS...GSP...ILM...MHX...RAH...

ATTN...RFC...SERFC...

LAT...LON   35607868 35257781 34707711 34097771 33817801 
            33677872 33327900 32907925 32667975 32358034 
            31948076 31518110 31528135 32068167 32638172 
            33768148 34678096 35178038 35547947