MESOSCALE PRECIPITATION DISCUSSION 0419
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
449 PM EDT FRI JUN 30 2017

AREAS AFFECTED...CENTRAL/EASTERN IN...CENTRAL/NORTHERN OH

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

VALID 302045Z - 010100Z

SUMMARY...ADDITIONAL TRAINING BANDS OF HEAVY SHOWERS AND
THUNDERSTORMS ARE EXPECTED OVER THE NEXT FEW HOURS. FLASH FLOODING
WILL BE LIKELY AS A RESULT GIVEN PERSISTENT AND INTENSE RAINFALL
RATES.

DISCUSSION...SHOWERS AND THUNDERSTORMS CONTINUE TO BECOME BETTER
ORGANIZED IN A SW/NE AXIS FROM PARTS OF SOUTHEAST IL NORTHEASTWARD
UP CENTRAL/NORTHEAST IN AND OVER NORTHERN OH. OVER THE LAST
HOUR...CLOUD TOPS HAVE BEEN COOLING A BIT FURTHER...OWING TO THE
INTERACTION OF A WELL-DEFINED SHORTWAVE/JET MAX MOVING ACROSS
CENTRAL IL AT THIS TIME AND INTERACTION WITH A VERY MOIST AND
MODERATELY UNSTABLE BOUNDARY LAYER ADVANCING NORTHEAST UP ACROSS
THE OH VALLEY.

THE CONVECTION WILL LIKELY TEND TO ORGANIZE A LITTLE BIT FURTHER
OVER THE NEXT COUPLE HOURS BEFORE PEAKING...BUT GIVEN THE LINEAR
BANDS ORIENTED RATHER PARALLEL TO THE DEEPER LAYER MEAN FLOW...THE
CONCERN FOR TRAINING CELLS WILL CONTINUE AND THUS WITH ENHANCED
RAINFALL POTENTIAL. A GENERAL EAST-NORTHEAST MOTION WITH SOME
GRADUAL TENDENCY FOR CONVECTION TO BOW OUT A BIT MORE TO THE EAST
CAN BE EXPECTED. THIS WILL ALLOW CONVECTION TO EVENTUALLY GET MORE
INTO CENTRAL OH BETWEEN 22Z AND 00Z.

PWATS APPROACHING 1.75 INCHES AND THE DEGREE OF AVAILABLE
INSTABILITY WILL CONTRIBUTE TO RAINFALL RATES OF OVER 2 INCHES/HR
WITHIN THE STRONGER CORES...AND THE LATEST HRRR GUIDANCE SUPPORTS
AS MUCH AS 3 TO 5 INCHES OF RAIN THROUGH MID-EVENING...WITH THE
HEAVIEST TOTALS UP ACROSS NORTHERN OH. SOME OF THE VERY HEAVY
RAINS WILL BE GETTING INTO THE CLEVELAND METROPOLITAN AREA...AND
MAY RESULT IN SOME ENHANCED RUNOFF/FLASH FLOODING CONCERNS AS A
RESULT GIVEN THE URBANIZED ENVIRONMENT. WILL CONTINUE TO MONITOR.

ORRISON

ATTN...WFO...CLE...ILN...IND...IWX...PBZ...

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

LAT...LON   41928051 41458039 40888102 40508246 40058423
            39468568 39508650 39908697 40268688 40808621
            41178532 41518423 41748297 41818175 41918096