MESOSCALE PRECIPITATION DISCUSSION 0434
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1110 PM EDT SUN AUG 09 2015
 
AREAS AFFECTED...SOUTHEAST MO...SOUTHERN IL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 100300Z - 100700Z
 
SUMMARY...POTENTIAL EXISTS FOR AN EXPANDING AXIS OF
BACKBUILDING/TRAINING CONVECTION OVER SOUTHEAST MO AND SOUTHERN IL
OVERNIGHT. FLASH FLOODING WILL BE LIKELY AT LEAST LOCALLY.

DISCUSSION...COLD-TOPPED CONVECTION IS REGENERATING SOUTH OF KSTL
IN RESPONSE TO INCREASINGLY CONFLUENT 850 MB FLOW WHICH IS
INTERACTING WITH A MESOSCALE BOUNDARY THAT WAS LAID DOWN BY THE
BOWING MCS MOVING THROUGH SOUTHERN IL CURRENTLY. ALREADY SEEING
SOME FLASH FLOOD CONCERNS DUE TO TRAINING AND THIS THREAT MAY
EXPAND OVER THE NEXT COUPLE OF HOURS.

CONSECUTIVE RUNS OF THE HRRR FAVOR AN EXCELLENT SET-UP FOR
BACKBUILDING AND TRAINING CONVECTION OVER THE NEXT FEW
HOURS...WITH SOME POTENTIAL FOR GREATER CONVECTIVE COVERAGE AS LOW
LEVEL MOISTURE CONVERGENCE INCREASES AND INSTABILITY BECOMES A BIT
MORE CONCENTRATED OVER SOUTHERN MO WHICH IS ALREADY SUGGESTED BY
THE LATEST GOES-SOUNDER DATA OVER THE AREA. PWATS ARE VERY HIGH
ALREADY...WITH VALUES EXCEEDING 2 INCHES. THIS DEEP CONCENTRATION
OF MOISTURE WILL FAVOR EXTREMELY HEAVY RAINFALL RATES.

THE SITUATION WILL CONTINUE TO BE MONITORED BUT EXPECT AT LEAST
THE POTENTIAL FOR 3 TO 5 INCH RAINFALL TOTALS OVER PARTS OF
SOUTHEAST MO WITH ISOLATED HEAVIER AMOUNTS WHERE STRONGER CORES
TRAIN OVER THE SAME.

ORRISON

ATTN...WFO...LSX...MEG...PAH...SGF...

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

LAT...LON   38909176 38909080 38358964 37588882 37038890 
            36538947 36589058 37209169 37819238 38379242 
            38759202