MESOSCALE PRECIPITATION DISCUSSION 0095
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
732 PM EDT WED JUN 04 2014
 
AREAS AFFECTED...LOWER OHIO VALLEYINTO NWRN KENTUCKY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 042331Z - 050331Z
 
SUMMARY...CONVECTION WITH RAINFALL RATES OF 1-2 IN/HR WILL SAG SWD
INTO SWRN KENTUCKY AND NWRN TENNESSEE THROUGH THE EARLY OVERNIGHT
HOURS AS AN 850 MB CONFLUENCE AXIS SLOWLY DROPS SOUTH. A NUMBER OF
HI-RES MODELS ARE SHOWING AGREEMENT IN HEAVY RAINFALL WHICH WOULD
EXCEED FLASH FLOOD GUIDANCE ACROSS THE LOWER OHIO VALLEY INTO NWRN
TENNESSEE.

DISCUSSION...A CLUSTER OF STORMS IS ONGOING ACROSS SRN ILLINOIS
INTO NWRN KENTUCKY AHEAD OF A SLOW MOVING COLD FRONT ANALYZED AT
23Z FROM SWRN OHIO...WWD ACROSS SWN INDIANA AND ILLINOIS INTO SERN
MISSOURI. HOURLY RAINFALL RATES OF 1 TO 2 INCHES HAVE BEEN
REPORTED PER RECENT ASOS AND COOP STATIONS IN SOME OF THE STRONGER
CORES. 

ONGOING CONVECTION LINES UP WITH AN AXIS OF CONFLUENCE AT 850 MB
TIED TO THE COLD FRONT...WHICH IS CO-LOCATED WITH PRECIPITABLE
WATER VALUES NEAR 1.75 INCHES. THE CONFLUENCE AXIS WILL SLOWLY
DROP SOUTH THROUGH 04Z INTO A REGION OF RICH LOW LEVEL MOISTURE
CHARACTERIZED BY DEWPOINTS IN THE LOW 70S ACROSS THE THREAT AREA.

WHILE INSTABILITY WILL BE WANING WITH NOCTURNAL
COOLING...UNIDIRECTIONAL WLY FLOW IN THE LOW AND MID LEVELS WILL
SUPPORT TRAINING OF CONVECTION INTO THE EARLY OVERNIGHT HOURS. A
NUMBER OF HI-RES MODELS WHICH HAVE BEEN HANDLING THIS EVENINGS
RAINFALL REASONABLY WELL ACROSS SRN ILLINOIS INTO KENTUCKY SUGGEST
A SLIGHT UPTICK IN CONVECTIVE COVERAGE WITH RAINFALL RATES OF 2-4
INCHES IN 3 HOURS WHICH WOULD CAUSE FLASH FLOODING...ESPECIALLY
ACROSS THE WESTERN PORTION OF THE THREAT AREA WHERE FFG VALUES ARE
AS LOW AS 2 INCHES IN 3 HOURS.

OTTO

ATTN...WFO...LMK...OHX...PAH...MEG...LSX...

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

LAT...LON   36609056 37829027 38338949 38208803 37728612 36778571
            36028611 35668675 35678796 36008998 36609056