MESOSCALE PRECIPITATION DISCUSSION 0309
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1150 AM EDT SAT JUN 04 2016
 
AREAS AFFECTED...SOUTHERN IL...SOUTHWEST/CENTRAL IN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 041545Z - 042045Z
 
SUMMARY...HEAVY SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON WITH INTENSE RAINFALL RATES THAT MAY BE ENOUGH TO CAUSE
SOME FLASH FLOODING.

DISCUSSION...A DEEPENING UPPER TROUGH IS SEEN IN WV IMAGERY
DIGGING SOUTHEAST ACROSS THE MIDWEST. THIS IS SENDING A FAIRLY
ROBUST COLD FRONT DOWN ACROSS THE REGION. MEANWHILE...DEEPER
TROPICAL MOISTURE THAT HAS POOLED WELL NORTH ACROSS THE LOWER AND
MID MS VALLEY DUE TO THE UPPER LOW OVER EAST TEXAS IS BECOMING
INCREASINGLY FOCUSED ALONG AND AHEAD OF THE FRONT AS DEPICTED BY
THE CIRA LPW PRODUCT. GPS PWATS ARE SEEN TO BE GENERALLY 1.5 TO
1.7 INCHES POOLED OUT JUST AHEAD OF THE FRONT.

STRENGTHENING LARGE SCALE ASCENT ASSOCIATED WITH 250 MB
RIGHT-ENTRANCE REGION JET DYNAMICS OVER CENTRAL AND SOUTHERN IL
COUPLED WITH LOW LEVEL CONVERGENCE AND A GRADUAL LOWERING OF
STATIC STABILITY THROUGH DIABATIC HEATING SHOULD FOSTER AN
EXPANSION OF SHOWERS AND THUNDERSTORMS FOR THE EARLY AND
MID-AFTERNOON HOURS WHICH WILL SHIFT INCREASINGLY MORE INTO
SOUTHWEST AND CENTRAL IN THROUGH THE AFTERNOON.

RAINFALL RATES GIVEN THE RELATIVELY DEEP POOL OF MOISTURE OVER THE
REGION SHOULD BE RATHER HIGH...AND MAY REACH UP TO ABOUT 2
INCHES/HR. THE DEEPER LAYER SOUTHWEST LOW/MID LEVEL FLOW OVER THE
REGION DOES FAVOR SOME BRIEF POTENTIAL FOR TRAINING CELLS...AND SO
THIS MAY ALLOW RAINFALL TOTALS TO REACH ON THE ORDER OF 3 TO 4
INCHES AND PERHAPS LOCALLY HEAVIER THIS AFTERNOON. SO THIS MAY
ALLOW FOR SOME ENHANCED POTENTIAL FOR SHORT-TERM FLASH FLOODING.

ORRISON

ATTN...WFO...ILX...IND...LSX...PAH...

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

LAT...LON   39948707 39918625 39408617 38518710 37658856 
            37368946 37738970 38228971 38798921 39548791