MESOSCALE PRECIPITATION DISCUSSION 0562
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
330 PM EDT SAT AUG 13 2016
 
AREAS AFFECTED...CENTRAL/NORTHERN AR...SOUTHEAST MO...FAR WESTERN
KY...SOUTHERN IL...CENTRAL/SOUTHWEST IN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 131930Z - 140000Z
 
SUMMARY...THE THREAT FOR SLOW-MOVING AND TRAINING BANDS OF INTENSE
BANDS OF SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS AFTERNOON
AND INTO THE EVENING HOURS. ADDITIONAL FLASH FLOODING IS LIKELY.

DISCUSSION...A QUASI-STATIONARY FRONT IS SITUATED FROM CENTRAL IND
SOUTHWEST DOWN ACROSS SOUTHERN IL/SOUTHEAST MO AND INTO NORTHWEST
AR. THERE CONTINUES TO BE WEAK WAVE ACTIVITY LIFTING NORTHEAST UP
ALONG THE FRONT. MEANWHILE...LOW TO MID LEVEL LOW PRESSURE
CONTINUES TO DRIFT EVER SO SLOWLY WEST ACROSS THE LOWER MS VALLEY.
AROUND THE NORTHERN AND EASTERN FLANKS OF THIS CIRCULATION IS A
RATHER WELL-DEFINED LOW LEVEL TRANSPORT REGIME OF VERY DEEP
TROPICAL AIR...WITH PWATS OF 2.25 TO 2.5 INCHES...AND THIS
MOISTURE CONTINUES TO SURGE NORTH INTO THE AFOREMENTIONED FRONTAL
ZONE. THIS ENHANCED MOISTURE CONVERGENCE ALONG WITH POOLING OF
INSTABILITY HAS BEEN RESPONSIBLE FOR AN EXTENSIVE AXIS OF HEAVY
SHOWERS AND THUNDERSTORMS...WHICH CURRENTLY EXTENDS FROM NORTHERN
AR NORTHEASTWARD UP ACROSS SOUTHERN IL AND THROUGH MUCH OF CENTRAL
IND.

THROUGH THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING
HOURS...THE FRONTAL ZONE WILL REMAIN QUASI-STATIONARY AND WILL
CONTINUE TO INTERACT WITH THE BROADER LOW AND MID LEVEL
CIRCULATION TO THE SOUTH. DEEPER MOISTURE AND DIURNALLY ENHANCED
INSTABILITY WILL AGAIN POOL ALONG THE BOUNDARY AND SHOULD SUSTAIN
THE CURRENT ACTIVITY THROUGH THE PERIOD. MEANWHILE...THE GUIDANCE
AGAIN INDICATES FAVORABLE 250 MB RIGHT-ENTRANCE REGION JET
DYNAMICS SETTING UP IN VICINITY OF THE FRONT WHICH WILL PROVIDE A
DYNAMIC FOCUS FOR STRONGER DEEPER LAYER ASCENT AND THUS HEAVY
RAINFALL.

RAINFALL RATES WILL BE AS HIGH AS 2.5 INCHES/HR AND COUPLED WITH
THE SLOW-MOVEMENT OF THE CELLS AND EXPECTATION OF
TRAINING...RAINFALL TOTALS WILL LOCALLY BE VERY HEAVY. EXPECT
ADDITIONAL RAINFALL AMOUNTS OF AS MUCH AS 3 TO 6 INCHES. THIS WILL
LIKELY RESULT IN ADDITIONAL FLASH FLOODING GIVEN EARLIER HEAVY
RAINS FROM TODAY.

ORRISON

ATTN...WFO...ILN...ILX...IND...IWX...LMK...LSX...LZK...MEG...
PAH...SGF...TSA...

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

LAT...LON   40958519 40608449 39988472 38968606 37498837 
            36519013 35449184 34879296 34509404 34749443 
            35269410 35899324 36639192 37499070 38538921 
            39588775 40518633