MESOSCALE PRECIPITATION DISCUSSION 0282
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
316 PM EDT SUN JUN 10 2018

AREAS AFFECTED...CENTRAL/EASTERN IL...WESTERN/CENTRAL IN

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 101915Z - 110115Z

SUMMARY...ADDITIONAL BANDS OF TRAINING SHOWERS AND THUNDERSTORMS
ARE EXPECTED THIS AFTERNOON. GIVEN EARLIER HEAVY RAINS AND THE
EXPECTATION OF ADDITIONAL HEAVY RAINFALL THIS AFTERNOON...FLASH
FLOODING IS LIKELY.

DISCUSSION...AN AXIS OF STRONG AND LOCALLY TRAINING SHOWERS AND
THUNDERSTORMS IS SEEN ADVANCING ACROSS AREAS OF CENTRAL AND
EASTERN IL AND WESTERN IN. THE CONVECTION IS GENERALLY ALONG AND
NORTH OF A QUASI-STATIONARY FRONTAL ZONE AND AHEAD OF A WAVE OF
LOW PRESSURE NORTH OF SPRINGFIELD IL.

THE AIRMASS SOUTH OF THE FRONT OVER SOUTHERN IL HAS BECOME VERY
UNSTABLE WITH MLCAPE VALUES OF AS MUCH AS 2000 TO 3000 J/KG OWING
TO STRONG SURFACE HEATING WITH SURFACE TEMPS IN THE LOW 90S AND
DEWPOINTS IN THE LOW 70S. THIS AIRMASS IS CONTINUING TO BE
ADVECTED UP AND OVER THE FRONT WITH THE AID OF THE DEVELOPING LOW
CENTER...AND BASED ON THIS SET-UP...STRONG BANDS OF CONVECTION
WITH SOME BACKBUILDING AND TRAINING OF CELLS SEEMS LIKELY AS THE
SURFACE LOW HAS BEEN SLOW TO ADVANCE EAST...AND THE ACTIVITY HAS
BEEN ALIGNING ITSELF NEARLY PARALLEL TO THE 850/300 MB LAYER MEAN
FLOW WHICH IS GENERALLY OUT OF THE WEST.

OVER THE NEXT SEVERAL HOURS GOING THROUGH 00Z...SOME VERY HEAVY
RAINFALL IS LIKELY...WITH ADDITIONAL AMOUNTS OF AS MUCH AS 3 TO 4
INCHES WITH ISOLATED HEAVIER AMOUNTS WHERE THE CORE OF STRONGER
TRAINING CELLS FOCUS. THERE MAY BE SOME PERIODIC BREAKS IN THE
CONVECTION...BUT ADDITIONAL UPSTREAM DEVELOPMENT OF CONVECTION
OVER WEST-CENTRAL IL WILL NEED TO BE MONITORED TOWARD EVENING AS
AN MCV AND RELATED UPSTREAM ENERGY OVER EASTERN IA BEGINS TO
ENCROACH ON THE REGION WHILE INTERACTING WITH THE AFOREMENTIONED
POOL OF STRONG INSTABILITY NEAR AND SOUTH OF THE FRONT.

BASED ON THE ADDITIONAL RAINFALL POTENTIAL AND SATURATING SOIL
CONDITIONS...FLASH FLOODING IS CONSIDERED LIKELY.

ORRISON

ATTN...WFO...ILN...ILX...IND...LOT...LSX...

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

LAT...LON   40648893 40638841 40568782 40458710 40178600
            39878538 39438515 38858565 38848739 39058883
            39488997 39929024 40329007 40518956