MESOSCALE PRECIPITATION DISCUSSION 0169
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 AM EDT MON JUL 22 2013
 
AREAS AFFECTED...CENTRAL IL INTO CENTRAL/SRN IN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 220617Z - 221130Z
 
SUMMARY...A DYNAMIC SMALL SCALE SHORT WAVE IS INTERACTING WITH A
STALLED FRONTAL ZONE AND PLUME OF DEEP TROPICAL MOISTURE OVER THE
OH VLY. HEAVY RAINFALL IS ANTICIPATED FOR THE NEXT SEVERAL HRS
FROM CENTRAL IL INTO IN... WHICH COULD LEAD TO LOCALIZED FLASH
FLOODING.

DISCUSSION...A DYNAMIC SHORT WAVE TROUGH IS PRESSING INTO THE WRN
PORTION OF THE OH VLY EARLY THIS MORNING AND IT APPEARS A POSSIBLE
MCV IS FORMING ALONG A QUASI-STATIONARY SURFACE BOUNDARY IN
CENTRAL IL. MEANWHILE... DEEP TROPICAL MOISTURE IS POOLING ALONG
THE OH RIVER AND 850MB INFLOW FROM THE SW APPEARS RATHER
CONTINUOUS OVER THE NEXT SEVERAL HRS. THE COMBO OF ACTIVE JET
DYNAMICS AND THIS ANOMALOUS 2" PW PLUME IS TRIGGERING SEVERAL
SPOTS OF ACTIVE CONVECTIVE HEAVY RAINFALL. IN THE PAST THREE
HRS... MESONET DATA AROUND CMI SUGGEST 1.5 TO 3 INCH AMOUNTS IN
THE SLOW MOVING CELLS WITH MORE ACTIVITY DEVELOPING DOWNSTREAM
ALONG THE FRONTAL ZONE OVER NRN KY AND SWRN OH. THIS ENTIRE
CLUSTER OF STORMS SHOULD CONTINUE TO ADVANCE DOWNSTREAM OVER THE
NEXT SEVERAL HRS BUT AT A VERY SLOW CLIP... AS 00Z RAOB DATA
SUGGESTED 850MB FLOW NEAR THE CONVERGENCE ZONE AT ONLY 5-10 KTS.
00Z ECMWF AND 05Z RAP REFRESH SUGGEST 1-3 INCH AMOUNTS IN
LOCALIZED SPOTS CONTINUING THROUGH 11-14Z THIS MORNING... WHICH
COULD RESULT IN FLASH FLOODING DESPITE THE MODEST FFG.

MUSHER

ATTN...WFO...ILN...LMK...IWX...IND...PAH...LOT...ILX...LSX...

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

LAT...LON   38168592 38328736 37948918 38208999 38918957 39488880
            40438830 41158640 40818542 40258463 39478355 38448440
            38168592