MESOSCALE PRECIPITATION DISCUSSION 0662
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
329 AM EDT SAT SEP 10 2016
 
AREAS AFFECTED...EASTERN MO...SOUTHERN IL AND IN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 100729Z - 101329Z
 
SUMMARY...CONTINUED WEST TO EAST TRAINING CONVECTION WILL MAINTAIN
AN ISOLATED TO SCATTERED FLASH FLOOD THREAT SPREADING EAST ACROSS
IL AND IN.

DISCUSSION...THE FLASH FLOOD THREAT DESCRIBED EARLIER IN MPD 660
WILL LIKELY CONTINUE OVER THE NEXT SEVERAL HOURS...SHIFTING EAST
INTO PORTIONS OF IL AND IN. THE HIGHEST THREAT CONTINUES TO BE
ALONG THE WARM AIR ADVECTION WING EXTENDING EAST FROM THE COLD
FRONT ALONG A STATIONARY BOUNDARY. STRONG LOW LEVEL SOUTHWESTERLY
FLOW INTO THIS BOUNDARY IS RESULTING IN AN ENHANCED REGION OF
MOISTURE FLUX CONVERGENCE AT THE NOSE OF THE LOW LEVEL JET...WHICH
COMBINED WITH DIVERGENT FLOW ALOFT IN THE RIGHT ENTRANCE REGION OF
AN UPPER JET...IS RESULTING IN THE CONTINUED CONVECTIVE
DEVELOPMENT. WHILE MEAN FLOW IS OFF TO THE NORTHEAST...THE STRONG
LOW LEVEL INFLOW IS RESULTING IN CONTINUED BACKBUILDING OF
CONVECTION ALONG THIS CONVERGENCE AXIS...WITH VERY LIGHT CORFIDI
VECTORS NOTED. 

THIS MOISTURE CONVERGENCE AXIS IS EXPECTED TO SHIFT EAST INTO IL
AND PORTIONS OF IN INTO THE EARLY MORNING HOURS. THIS TRAINING
COMBINED WITH NEAR RECORD PRECIPITABLE WATER VALUES FOR THIS TIME
OF YEAR SURPASSING 2"...WILL RESULT IN LOCALLY HEAVY
RAINFALL...WITH LOCALIZED AMOUNTS AS HIGH AS 2-4". THIS MAY RESULT
IN SCATTERED FLASH FLOOD ISSUES...ESPECIALLY IN AREAS THAT HAVE
ALREADY RECEIVED HEAVIER RAINFALL AMOUNTS RECENTLY. RECENT RUNS OF
THE HRRR APPEAR TO BE DOING AN ALRIGHT JOB DEPICTING THE
EVOLUTION...ALTHOUGH BASED ON CURRENT RADAR TRENDS...THE 05Z HRRR
MAY BE TOO FAR NORTH WITH ITS QPF AXIS. CURRENT INDICATIONS ARE
THAT BY AROUND 12Z OR 13Z THE MOISTURE CONVERGENCE AXIS BEGINS TO
WEAKEN...WHICH SHOULD RESULT IN A DOWNWARD CONVECTIVE TREND.

CHENARD

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

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

LAT...LON   39878541 39158496 38368632 38068835 38028984 
            38039003 38129093 38469154 38999110 39109047 
            39308910 39638700 39728660