MESOSCALE PRECIPITATION DISCUSSION 0928
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1017 PM EST SUN NOV 05 2017

AREAS AFFECTED...SRN IN...SRN OH...FAR NRN KY AND FAR WRN WV

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 060316Z - 060715Z

SUMMARY...LOCALIZED FLASH FLOODING WILL REMAIN POSSIBLE FOR
ANOTHER FEW HOURS ACROSS PORTIONS OF THE OHIO VALLEY WITH RAINFALL
RATES DIMINISHING FROM 1-2 IN/HR TO ABOUT 1 IN/HR THROUGH 07Z.
ADDITIONAL RAINFALL OF 1.5 TO 2.5 INCHES WILL BE POSSIBLE WHERE
CELL TRAINING IS FAVORED.

DISCUSSION...EXPERIMENTAL GOES 16 10.3 MICRON IMAGERY SHOWED
WARMING CLOUD TOPS OVER IN/OH OVER THE PAST 1-2 HOURS SUGGESTIVE
OF WEAKENING UPDRAFT INTENSITY OWING TO WANING INSTABILITY. THE
00Z SOUNDING FROM ILN AND THE SPC MESOANALYSIS PAGE SHOWED
AVAILABLE CAPE TO BE GENERALLY LESS THAN 500 J/KG ACROSS SRN IN/OH
INTO NRN KY. HOWEVER...HIGHLY ANOMALOUS MOISTURE REMAINS WITH AREA
PRECIPITABLE WATER VALUES OF 1.4 TO 1.5 INCHES...NEAR THE 95TH
PERCENTILE FOR ILN. MESONET OBSERVATIONS NORTH OF CINCINNATI
SUPPORTED 1-HR RAINFALL RATES NEAR 2 IN/HR ENDING AT 03Z...A BIT
HIGHER THAN MRMS ESTIMATES...BUT TRENDS IN MRMS RAIN RATES HAVE
BEEN DECREASING OVER THE PAST 90 MINUTES.

03Z SURFACE OBSERVATIONS SHOWED A WEAK 1007 WAVE NEAR HNB ALONG
THE GENERALLY PROGRESSIVE COLD FRONT...WITH THE AREA JUST EAST OF
THE SURFACE WAVE LOCATED IN THE RIGHT ENTRANCE REGION OF A 90-110
KT UPPER LEVEL JET STREAK. RAP FORECASTS INDICATE THIS JET STREAK
WILL CONTINUE TO MOVE NORTHEASTWARD...AWAY FROM THE OHIO VALLEY
BUT REMNANT UPPER DIVERGENCE/DIFFLUENCE WILL REMAIN OVER THE
REGION ALONG WITH TRAINING OF CELLS FROM WEST TO EAST FOR ANOTHER
COUPLE OF HOURS. WHILE WEAKENING...THE FLASH FLOOD THREAT WILL
REMAIN EAST OF THE SURFACE LOW ALONG THE OHIO RIVER FROM SRN
IN...SRN OH INTO NRN KY...WITH RAINFALL RATES LIKELY FALLING BELOW
1 IN/HR SHORTLY BEYOND 07Z.

OTTO

ATTN...WFO...ILN...IND...JKL...LMK...RLX...

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

LAT...LON   39568401 39518242 39318170 38928169 38538215
            38288292 38238377 38238544 38368658 39108635