MESOSCALE PRECIPITATION DISCUSSION 0202
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
804 PM EDT WED MAY 11 2016
 
AREAS AFFECTED...SOUTHEASTERN MO/SOUTHERN IL/SOUTHERN IN/WESTERN
TO CENTRAL KY... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 120003Z - 120403Z
 
SUMMARY...HEAVY RAINFALL CONTINUES TO FALL ALONG THE LEADING EDGE
OF AN MCS BOWING OUT ACROSS SOUTHWESTERN IN. MEANWHILE...ALONG THE
WESTERN EXTENT OF THE COMPLEX...BACKBUILDING CONVECTION CONTINUES
OVER EAST-CENTRAL MO WHERE UPDRAFTS HAVE REGENERATED ALONG THE
NOSE OF MAXIMUM INFLOW. GIVEN LARGE AMOUNTS OF INSTABILITY STILL
IN PLACE ACROSS MUCH OF SOUTHERN MO...EXPECT THUNDERSTORMS TO
FURTHER DEVELOP TOWARD THE OVERNIGHT HOURS. FLASH FLOODING WILL
REMAIN POSSIBLE IN THE MPD AREA...BUT ESPECIALLY ALONG THE
TRAINING ELEMENTS/MERGING PRECIPITATION SEGMENTS OVER EASTERN MO. 

DISCUSSION...A CONVECTIVE COMPLEX WHICH EMERGED IN THE VICINITY OF
ST. LOUIS MO AROUND 18Z HAS CONTINUED TO PRODUCE ABUNDANT HEAVY
RAINFALL ALONG WITH SEVERE WEATHER. THE EASTERN FLANK OF THIS
CLUSTER HAS BEEN MORE PROGRESSIVE IN NATURE AS THE LEADING
CONVECTIVE LINE HAS BEGUN TO BOW OUT ALONG THE OH RIVER BOUNDING
IN/KY. LOCALLY HEAVY RAINFALL MAY PRODUCE ISOLATED OCCURRENCES OF
FLASH FLOODING. MEANWHILE...THE CONVECTION CONTINUALLY
REGENERATING ALONG THE MO/IL BORDER HAS BEEN BACKBUILDING/TRAINING
AT POINTS IN TIME THE PAST FEW HOURS. IT APPEARS TO BE FOCUSING
ALONG AN OLD OUTFLOW BOUNDARY EXTENDING FROM SOUTH OF ST. LOUIS MO
TOWARD THE NORTHWEST. THIS LOCATION HAS REMAINED IN A FAVORABLE
SPOT AS MIXED-LAYER CAPES IN THE 2000 TO 3000 J/K RANGE OVERLAPS
WELL WITH THE MAXIMUM LOW-LEVEL MOISTURE ADVECTION.

MODELS HAVE NOT HANDLED THIS SITUATION VERY WELL ALTHOUGH THEY
HAVE BEEN USEFUL WITH SOME OF THE MASS FIELDS. EXPECT THE BEST
THREAT FOR FLASH FLOODING ANYWHERE WITHIN THE WESTERN EXTENT OF
THE MPD WHERE CELL MOTIONS WILL BE SLOWER OR NEARLY STATIONARY AT
TIMES. HOURLY RAINFALL RATES OF 1 TO 1.50 INCHES ARE POSSIBLE.

RUBIN-OSTER

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

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

LAT...LON   39529123 39329084 38599057 38279021 38118950 
            38088884 38038831 37918721 38218690 38918642 
            38928553 38508517 37428562 36908671 36938845 
            37118997 37479097 37979154 38589189 39019206 
            39519173