MESOSCALE PRECIPITATION DISCUSSION 0461
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
116 PM EDT WED JUL 13 2016
 
AREAS AFFECTED...EASTERN SHORE OF MD...DE...SOUTHEAST
PA...SOUTHWEST NJ 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 131715Z - 132215Z
 
SUMMARY...SLOW HIGHLY EFFICIENT THUNDERSTORMS CAPABLE OF RATES
OVER 2"/HR WITH POTENTIAL OF UPSTREAM REDEVELOPMENT MAY POSE
LOCALIZED FLOODING CONDITIONS.

DISCUSSION...12Z WAL SOUNDING INDICATED A DEEPLY MOIST PROFILE
WITH SUFFICIENT SKINNY CAPE TO 1500 J/KG FOR STRONG UPDRAFTS
CAPABLE OF EFFICIENT RAINFALL.  COMPOUND THIS WITH WEAK WIND
PROFILES INDICATIVE OF LESS THAN 10 KT MOTIONS TOWARD NORTHEAST
HAS SUPPORTED RATES UP TO 2" AND SOME REPORTS NEAR KESN NEAR 3"
ALREADY. 

GOES-EAST VIS IMAGERY SHOWS A WEAK SURFACE/LOW LEVEL TWIST NEAR
KNYG ALONG A WEAK WARM FRONT/SURFACE TROF FROM CENTRAL PA TO E VA.
ADDITIONALLY CONFLUENT/CONVERGENT WINDS ACCELERATED THROUGH THE
CHESAPEAKE BAY WILL KEEP UPSTREAM CONVERGENCE ALONG THE COASTS OF
THE BAY THIS AFTERNOON. AS THE EARLY MORNING CLOUDS HAVE BURNED
OFF TO ALLOW FOR SOLAR INSOLATION TO INCREASE OVER CENTRAL
MD...AHEAD OF THE FRONT.  INSTABILITY HAS REBOUNDED TO SIMILAR
SKINNY 1500-2000 J/KG WITH TPWS OVER 2" PROVIDING SUPPORT FOR
UPSTREAM REDEVELOPMENT FOR ADDITIONAL ROUND(S) OF CONVECTION
THROUGH THE AFTERNOON/EARLY EVENING HOURS. ONLY LIMITING FACTOR
FOR FLOODING IS LOCAL GUIDANCE IS VERY HIGH DUE TO DRY AND SANDY
SOIL CONDITIONS...STILL SOME HI-RES CAM GUIDANCE INCLUDING THE
ARW/NMMB AND FEW RUNS OF THE HRRR SUPPORT TOTALS NEARING FFG AT
3-4" BY 00Z...PARTICULARLY ACROSS THE NORTHERN PORTION OF THE
EASTERN SHORE...POTENTIALLY INTO SW NJ/DELAWARE RIVER VALLEY.  

GALLINA

ATTN...WFO...AKQ...PHI...

ATTN...RFC...MARFC...

LAT...LON   40367467 39697477 39267483 38787497 38477519 
            38277549 38357584 38637621 38867627 39257619 
            39507600 39717587 40327522