MESOSCALE PRECIPITATION DISCUSSION 0339
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
224 AM EDT TUE SEP 02 2014
 
AREAS AFFECTED...ERN MO...SRN IL...SRN IN...FAR NRN KY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 020623Z - 021023Z
 
SUMMARY...STRONG INFLOW AND SUFFICIENT INSTABILITY WILL SUSTAIN
CONVECTION IN A RELATIVELY FOCUSED CORRIDOR THROUGH 10-11Z. WITH
RAINFALL ABOVE 1.5"/HR ALREADY OBSERVED...ANY TRAINING MAY PRODUCE
FLASH FLOODING.

DISCUSSION...THE CHARACTER OF THIS EVENT HAD ALREADY REVEALED
ITSELF. LEADING LINE CONVECTION ENTERING INDIANA WAS PRODUCING
GAUGE OBS ABOVE 1.5"/HR AND HIGHER RADAR ESTIMATED RAINFALL
BETWEEN OBS SITES. RATHER THAN PROPAGATING INTO THE NEAR SURFACE
INFLOW...UPSTREAM CONVECTION WAS FORMING ALOFT IN A ZONE OF
ENHANCED 850-700 MB INFLOW/CONVERGENCE...AND AHEAD OF A 700 MB
TROUGH ENTERING CENTRAL MISSOURI.

AS CONVECTION FOLLOWS THE MEAN WIND... MULTIPLE CLUSTERS AND LINE
SEGMENTS MAY TRAIN OVER THE SAME AREAS...YIELDING SPOTTY 2-4 INCH
RAIN TOTALS OVER 2-4 HOURS...AND POTENTIAL FLASH FLOODING. THE RAP
FORECASTS SUFFICIENT CAPE TO SUSTAIN THIS REGIME TO AT LEAST
10-11Z...ESPECIALLY OVER MO/IL AND SOUTHWEST INDIANA. INSTABILITY
AND INTENSITY DECREASE WITH EASTWARD EXTENT...AND ARE LIKELY TO
SHOW A GRADUAL DECREASE FARTHER WEST. WHILE MANY MODELS ARE IN THE
NEIGHBORHOOD...THE 00Z NSSL WRF AND 04Z HRRR APPEAR TO HANDLE THIS
EVENT PARTICULARLY WELL JUDGING BY THEIR RESPECTIVE SIMULATED
REFLECTIVITY PRODUCTS...WHICH SHOW TRAINING CONVECTION AND ONE OR
TWO SWATHS OF FOCUSED...HEAVY RAIN.

BURKE

ATTN...WFO...ILN...LMK...IND...PAH...ILX...LSX...SGF...

ATTN...RFC...LMRFC...MBRFC...NCRFC...OHRFC...

LAT...LON   39708552 39608516 39018498 38018716 37338999 37349198
            37949276 38699202 39558785 39708552