MESOSCALE PRECIPITATION DISCUSSION 0326
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
836 PM EDT THU JUN 09 2016
 
AREAS AFFECTED...SRN WISCONSIN...NRN ILLINOIS...NRN INDIANA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 100033Z - 100600Z
 
SUMMARY...CONVECTION IS EXPECTED TO EXPAND OVER THE NEXT FEW HOURS
WHILE TRAINING FROM NORTHWEST TO SOUTHEAST ACROSS PORTIONS OF THE
UPPER MIDWEST. RAINFALL RATES OF 1-2 IN/HR REPEATING OVER THE SAME
LOCATION MAY CONTRIBUTE TO FLASH FLOODING THROUGH 06Z.

DISCUSSION...AT 00Z...A STATIONARY FRONT EXTENDED SEWD THROUGH
IOWA AND THEN EAST ACROSS N-CNTRL ILLINOIS AND INDIANA. RECENT SPC
MESOANALYSES INDICATED THAT A NARROW AXIS OF ML AND MU CAPE OF
2000-3000 J/KG EXTENDED FROM SERN MINNESOTA INTO NERN IOWA...WHILE
LOCATIONS ACROSS NERN ILLINOIS INTO NWRN INDIANA HAD LESS THAN 500
J/KG OF INSTABILITY. RADAR/SATELLITE OBSERVATIONS HAVE SHOWN
SCATTERED ELEVATED THUNDERSTORMS HAVE DEVELOPED OVER THE PAST HOUR
IN FAR SRN WISCONSIN...MOVING TOWARD THE SOUTHEAST AT 20-25
KTS...ON THE EDGE OF THE INSTABILITY AXIS.

VAD WIND PLOTS FROM KDVN AND KLOT SHOWED 850-700 MB FLOW OF 20-30
KTS FROM THE WSW OVERRUNNING THE BOUNDARY IN THE PRESENCE OF
PRECIPITABLE WATER VALUES HOVERING NEAR AND ABOVE 1.5 INCHES VIA
RECENT GPS SENSOR LOCATIONS AND CONFIRMED BY 00Z KDVN SOUNDING.
SHORT TERM FORECASTS FROM THE RAP INDICATE VEERING OF LOW LEVEL
WINDS OVERNIGHT ACROSS THE WISCONSIN/ILLINOIS BORDER WHICH WOULD
BECOME MORE PARALLEL TO MEAN STORM MOTION VECTORS. GIVEN THE
PRESENCE OF AMPLE INSTABILITY UPSTREAM...THIS MAY LEAD TO
EXCEEDANCE OF FLASH FLOOD GUIDANCE VALUES CURRENTLY SHOWING 2-3
INCHES IN 3 HOURS IN THE MPD THREAT AREA. 

HI-RES MODELS SHOW DECENT AGREEMENT ON THIS SETUP BUT DO NOT AGREE
WITH TIMING OR MAGNITUDE OF HEAVY RAINFALL. HOWEVER...GIVEN THE
CURRENT EVOLUTION OF CONVECTION...FEEL THE FLASH FLOOD THREAT WILL
SIGNIFICANTLY INCREASE IN THE NEXT COUPLE OF HOURS NEAR THE
WISCONSIN/ILLINOIS BORDER...PERHAPS MOVING SOUTH WITH TIME.

OTTO

ATTN...WFO...ARX...DVN...ILX...IND...IWX...LOT...MKX...

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

LAT...LON   43868959 43398864 42778783 41978681 41408616 
            40718608 40418691 40498802 41128923 41728999 
            42779060 43749054