MESOSCALE PRECIPITATION DISCUSSION 0556
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
815 AM EDT MON OCT 05 2015
 
AREAS AFFECTED...NORTHEASTERN SC/COAST OF NC... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 051214Z - 051644Z
 
SUMMARY...THE AXIS OF HEAVY RAINFALL CONTINUES TO DRIFT NORTHWARD
WITH THE ACTIVITY CONCENTRATING ACROSS SOUTHEASTERN NC/THE LOWER
OUTER BANKS THE NEXT FEW HOURS. THE EARLY MORNING CONVECTION
SHOULD CONTINUE TO AFFECT AREAS WHICH HAVE SEEN EXTREMELY HEAVY
RAINFALL IN RECENT DAYS.

DISCUSSION...WATER VAPOR IMAGERY SHOWED A COMPACT UPPER LOW
CURRENTLY SPINNING JUST OFF THE COAST OF DAYTONA BEACH FL. A
WELL-DEFINED UPPER DIFFLUENCE SIGNATURE IS LOCATED NORTH OF THIS
UPPER CYCLONE WHERE TREMENDOUS MOISTURE IS BEING TRANSPORTED FROM
HURRICANE JOAQUIN. THE BLENDED-TPW AND GPS DATA SUPPORT ABOVE 2
INCH PWATS IMPINGING ON THE NC/SC COASTLINE. MODELS AND
OBSERVATIONAL DATA SHOW THIS ENHANCED BAND OF MOISTURE GRADUALLY
LIFTING NORTHWARD WHICH WILL SLOWLY CARRY THE HEAVY RAINFALL
THREAT INTO THE LOWER OUTER BANKS. CURRENT HOURLY RAINFALL RATES
PER METARS AND MESONET DATA SUGGEST A BROAD AREA OF 0.25 TO 0.50
INCH AMOUNTS WITH POCKETS OF 1 TO 1.25 INCH VALUES WITHIN THE MORE
ROBUST PRECIPITATION CORES. OF COURSE ANY RAINFALL ON TOP OF THE
EXTREMELY SATURATED SOILS ACROSS EASTERN SC WITH FURTHER
EXACERBATE THE FLASH FLOODING ISSUES.

A VAST MAJORITY OF THE RECENT CAMS...INCLUDING THE HOURLY UPDATE
MODELS...HAVE BEEN TOO FAR OFFSHORE WITH THE ONGOING CONVECTION.
THERE IS A DECENT HEAVY RAINFALL SIGNAL IN THESE MODELS WHICH IS
IN LINE WITH THE CURRENTLY THINKING. HOWEVER...SUCH DISPLACEMENT
ERRORS MADE THE FORECAST QPF AREAS A BIT MORE UNRELIABLE.

RUBIN-OSTER

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

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

LAT...LON   35327568 34767513 33977540 33867658 33677780 
            33127988 33828047 35277714