MESOSCALE PRECIPITATION DISCUSSION 0030
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
332 PM EDT WED APR 08 2015
 
AREAS AFFECTED...EASTERN MO...SOUTHERN IL...SOUTHERN IN...NORTHERN
KY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 081930Z - 082230Z
 
SUMMARY...CLUSTERS OF HEAVY SHOWERS AND THUNDERSTORMS EXPECTED
THROUGH THIS EVENING. SOME FLASH FLOODING IS POSSIBLE GIVEN RECENT
RAINS.

DISCUSSION...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AND
EXPAND IN COVERAGE THIS AFTERNOON ACROSS PORTIONS OF THE LOWER MO
AND OH VALLEYS. THIS WILL OCCUR AS STRENGTHENING WARM AIR
ADVECTION INTERACTS WITH A REMNANT OUTFLOW BOUNDARY COUPLED WITH
STRONG DIURNAL HEATING AND MOISTURE TRANSPORT. GOES-SOUNDER LI/S
ARE NOW AS LOW AS -10 OVER PORTIONS OF CENTRAL MO...AND THE LATEST
VIS IMAGERY CONFIRMS AN EXPANDING CU/TCU FIELD THAT SUGGESTS
INCREASED SURFACE BASED INSTABILITY. THIS THERMODYNAMIC ENERGY
WILL BE A PART OF A BROADER SOUTHWEST FLOW REGIME THAT WILL
INTERSECT THE AFOREMENTIONED OUTFLOW BOUNDARY THROUGH THE
REMAINDER OF THE DAY.

THE 12Z NAM-CONEST AND RECENT RUNS OF THE HRRR SUGGEST CONVECTION
ORGANIZING INTO MULTIPLE CLUSTERS OVER THE NEXT FEW HOURS WITH A
PROPAGATION GENERALLY W/E THROUGH THE AFTERNOON. THE OUTFLOW
BOUNDARY THOUGH MAY FOCUS CONVECTION WITH A MORE LINEAR W/E MODE
SUCH THAT TRAINING CONVECTION MAY RESULT ALONG WITH BACK-BUILDING
OF CELLS GIVEN THE UPWIND TRANSPORT OF MOISTURE/INSTABILITY.

GIVEN RECENT HEAVY RAINS FOR PORTIONS OF THE THREAT
AREA...ADDITIONAL HEAVY CONVECTIVE RAINS WILL FOSTER THE POTENTIAL
FOR FLASH FLOODING. RECENT HRRR RUNS SUPPORT POTENTIAL FOR 3 TO 5
INCH RAINFALL AMOUNTS AT LEAST LOCALLY THROUGH 00Z. WILL CONTINUE
TO MONITOR THROUGH THE AFTERNOON.

ORRISON

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

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

LAT...LON   39348791 39298623 39098487 38628383 37878384 
            37828524 38008722 37948868 37819005 37939107 
            38209185 38689176 38989099 39288913