MESOSCALE PRECIPITATION DISCUSSION 0571
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
818 AM EDT SAT OCT 10 2015
 
AREAS AFFECTED...SOUTH CAROLINA...S NORTH CAROLINA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 101217Z - 101817Z
 
SUMMARY...SHORT TERM HIGH RATES MAY LEAD TO ISOLATED COMPOUNDED
FLOODING CONCERNS.

DISCUSSION...INCREASINGLY DEFINING UPPER LOW STARTING TO DRAW BACK
AN EXPANDING BAROCLINIC LEAF WITH A 75-80 KT JET ROUNDING THE BASE
OF THE OVERALL TROF.  OVERALL EXCELLENT PVA/SYNOPTIC DYNAMICS IN
PLACE FOR CONTINUED EXPANSION OF MODERATE SHIELD PRECIPITATION
POST FRONTALLY.   AT THE SURFACE WEAK SURFACE LOW NEAR CAE LIFTING
SLOW ENE ALONG STATIONARY FRONT DRAPED ACROSS N SC INTO S NC AND
NC OUTER BANKS AND A COLD FRONT DROPS SW INTO CENTRAL GA.   AHEAD
OF THE FRONT WEAK INSTABILITY REMAINS IN PLACE ALOFT WITH 500-1000
J/KG AVAILABLE...AND GIVEN THE PROGRESS OF THE FRONT EASTWARD IS
PROVIDING SUFFICIENT LIFT TO CONVECT AS THERE IS NO EASTERLY
INFLOW.  THIS ALLOWS FOR CONTINUED RELATIVELY PROGRESSIVE
CONVECTIVE LINE OF CYCLING COLD/WARMING TOPS IN IR.  TPWS ARE IN
THE 1.75" RANGE SO RAINFALL RATES OF 2"/HR ARE POSSIBLE, LEAVING A
SWATH OF 1-1.75" TOTALS OVER THE NEXT FEW HOURS ACROSS CENTRAL SC
INTO E SC.  

WEAK CONVERGENCE IS ALSO LEADING TO SOME SCATTERED SHALLOW CELLS
ALONG THE STATIONARY FRONT...THIS MAY ALLOW FOR SOME MERGERS ALONG
THIS BOUNDARY AS THE LOW SHIFTS ENE.  EVENTUALLY AS THE JET ENERGY
SWINGS AROUND THE BASE...THE UPPER LOW WILL CONTINUE TO ENHANCE
AND CUT-OFF SLOWING FORWARD PROGRESS OF THE SURFACE LOW AND CELL
MOTIONS ALONG IT...WITH THE POTENTIAL OF ENHANCING MODERATE
SHOWERS ALONG THE DEFORMATION ZONE OVER UPSTATE SC TO CENTRAL SC
BACK TO THE UPPER LOW AS IT TRACKS SE THIS AFTERNOON.  SOME
ADDITIONAL CLEARING NEAR THE UPPER LOW MAY SUPPORT SOME INCREASED
SURFACE BASED HEATING ON THE SW EDGES TO SUPPORT ADDITIONAL
CONVECTIVE GROWTH NEAR THE DEFORMATION/CENTROID OF THE UPPER LOW
BY 18-20Z. 

OVERALL THERE REMAINS A SHORT TERM FLASH FLOOD THREAT MAINLY
DRIVEN BY HIGH RATES PARTICULARLY WHERE RUNOFF CANNOT RUNOFF FAST
ENOUGH DUE TO INUNDATED STREAMS/RIVERS. 

GALLINA  

ATTN...WFO...CAE...CHS...FFC...GSP...ILM...

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

LAT...LON   34908260 34878140 34738029 34617942 34377869 
            33937840 33457870 33057930 32628043 32698096 
            33358187 33678215 34078293 34698289