MESOSCALE PRECIPITATION DISCUSSION 0261
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
315 PM EDT SUN AUG 10 2014
 
AREAS AFFECTED...EASTERN SC 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 101914Z - 110114Z
 
SUMMARY...PULSE THUNDERSTORMS WITH HOURLY RAIN RATES UP TO 2.5"
COULD CAUSE FLASH FLOODING ALONG A NEARBY FRONT AND SLOWLY
PROGRESSIVE SEA BREEZE BOUNDARY.

DISCUSSION...A FRONTAL ZONE CURRENTLY STRETCHES THROUGH CENTRAL SC
FROM SOUTH OF MYRTLE BEACH TOWARDS AUGUSTA GA, WITH WEAK SURFACE
TROUGHING -- LIKELY INDUCED BY THE SEA BREEZE CIRCULATION -- JUST
INLAND OF THE SOUTHERN SC AND GA COASTS WITH A WEAK LOW NORTHWEST
OF BRUNSWICK GA.  CAPE VALUES IN THE REGION ARE 1000-3000 J/KG PER
THE SPC MESOANALYSIS PAGE.  INFLOW IS WEAK WHICH SHOULD LEAD TO
PULSE THUNDERSTORM DEVELOPMENT, BUT MOISTURE IS SIGNIFICANT, WITH
PRECIPITABLE WATER VALUES OF ~2.25".  THIS ALLOWS FOR HOURLY RAIN
RATES UP TO 2.5", WHICH APPEAR TO BE REALIZED PER RECENT CHS
OBSERVATIONS.

THE 12Z SSEO NEIGHBORHOOD PROBABILITIES SHOW A 50-70% CHANCE OF
EXCEEDING FLASH FLOOD GUIDANCE ALONG THE ENTIRE SC COAST THROUGH
02Z, WHICH APPEARS REASONABLE CONSIDERING THE MOISTURE
AVAILABILITY AND EXPECTED PERSISTENCE OF THE INSTABILITY IN RECENT
RAP RUNS.  THE AREA HAS SEEN A BIT OF RAINFALL SINCE YESTERDAY
AFTERNOON, WHICH HAS SLIGHTLY LOWERED FLASH FLOOD GUIDANCE VALUES.
 THE MESOSCALE GUIDANCE ADVERTISES LOCAL AMOUNTS OF 3-5" IN THIS
REGION.  FLASH FLOODING IS CONSIDERED POSSIBLE.

ROTH

ATTN...WFO...ILM...CHS...CAE...JAX...FFC...

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

LAT...LON   31828214 33448254 34297993 34247842 33917819 33667880
            33627892 33167915 32677985 32118065 31888108 31828214