MESOSCALE PRECIPITATION DISCUSSION 0545
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
407 AM EDT SAT OCT 03 2015
 
AREAS AFFECTED...SC/WESTERN HALF OF NC... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 030806Z - 031406Z
 
SUMMARY...INTENSE HEAVY RAINFALL CONTINUES ACROSS MUCH OF THE
STATE OF SC AND EXTENDING INTO WESTERN NC. THE CONVECTION HAS
FOCUSED ALONG A NORTHWEST-SOUTHEAST ORIENTED TROPICAL PLUME OF
MOISTURE WITH A CONNECTION TO HURRICANE JOAQUIN. GIVEN A HISTORY
OF PRODUCING EXTREME 24-HOUR RAINFALL TOTALS OF 10 TO 15
INCHES...FLASH FLOODING WILL REMAIN LIKELY THROUGH THE MORNING
HOURS.

DISCUSSION...WATER VAPOR IMAGERY EARLY THIS MORNING SHOWED AN
UPPER LOW CIRCULATING OVER THE FL PANHANDLE WITH A BROAD RIDGE
EXTENDING ACROSS THE WESTERN ATLANTIC. THESE COMBINED CIRCULATIONS
HAVE HELPED CHANNEL A NARROW PLUME OF MOISTURE FROM THE VICINITY
OF HURRICANE JOAQUIN AND EXTENDING NORTHWESTWARD INTO THE
SOUTHEASTERN U.S. THE BLENDED-TPW PRODUCT SUGGESTED THE EXTENT OF
THE 2" PWAT WITHIN THE TROPICAL MOISTURE PLUME WAS APPROXIMATELY
175 MILES. DURING THE PAST 12 HOURS...THE ORIENTATION OF THIS
ENHANCED TROPOSPHERIC MOISTURE AXIS HAS CHANGED VERY LITTLE WHICH
HAS DIRECTED VERY INTENSE TROPICAL RAINFALL INTO SC/NC. MESONET
OBSERVATIONS IN THE VICINITY OF MYRTLE BEACH SC SHOWED 8 TO 10
INCHES OF RAINFALL HAS ALREADY FALLEN WITH ISOLATED HIGHER AMOUNTS
ACROSS SOME SURROUNDING LOCATIONS. 

CURRENT SATELLITE IMAGERY AND LIGHTNING DATA SHOWS A PERSISTENT
AREA OF CONVECTIVE REGENERATION JUST OFFSHORE OF CHARLESTON SC
WITH AN INCREASE IN LIGHTNING ACTIVITY ACROSS THIS REGION. THE 07Z
RAP OBJECTIVE ANALYSIS INDICATED THIS CONTINUAL REGENERATION
PROCESS IS OCCURRING IN THE PRESENCE OF MUCAPES ABOVE 3000 J/KG
WITH 500 TO 1000 J/KG VALUES EXTENDING ALONG THE MOISTURE PLUME
INTO UPSTATE SC. HOURLY RAINFALL RATES IN THE 1 TO 2 INCH RANGE
ARE LIKELY ALONG THE COAST WITH SLIGHTLY LOWER RATES FARTHER
INLAND WHERE THE INSTABILITY DECREASES. THE PAST 6 RUNS OF THE
HRRR ARE QUITE CONSISTENT PAINTING HEAVY RAINFALL ALONG THE
TROPICAL MOISTURE PLUME WHICH RAISES CONFIDENCE IN THE DRAWN AREA.
OTHER RECENT CAMS ALSO SHOW SUPPORT FOR THESE HRRR RUNS.

RUBIN-OSTER

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

ATTN...RFC...LMRFC...OHRFC...SERFC...

LAT...LON   36358128 36098038 35277955 34257880 32917856 
            32027901 31958054 33288155 34878255 35958243