868
AWUS01 KWNH 152148
FFGMPD
WIZ000-ILZ000-IAZ000-160246-
MESOSCALE PRECIPITATION DISCUSSION 0108
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
547 PM EDT WED APR 15 2026
AREAS AFFECTED...SOUTHERN WISCONSIN, NORTHERN ILLINOIS
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY
VALID 152146Z - 160246Z
SUMMARY...THUNDERSTORMS WILL MIGRATE EASTWARD ACROSS WET/SENSITIVE
AREAS FROM YESTERDAY'S RAINFALL ESPECIALLY ACROSS WISCONSIN.
FLASH FLOODING IS LIKELY.
DISCUSSION...SCATTERED THUNDERSTORMS HAVE ORGANIZED ALONG A
FRONTAL BOUNDARY FROM JUST NORTH OF DUBUQUE TO DES MOINES. THE
STORMS ARE EXHIBITING LINEAR ORGANIZATION SO FAR IN THEIR
EVOLUTION, WITH FORWARD PROPAGATION AND 40-50 KT SPEEDS GENERALLY
LIMITING THEIR RAINFALL POTENTIAL TO AROUND 1 INCH/HR OR LESS.
FLASH FLOODING IS POSSIBLE ON AN ISOLATED BASIS IN THE SHORT TERM.
OVER THE NEXT 1-4 HOURS, HOWEVER, STORMS WILL MIGRATE EASTWARD
ALONG A REMNANT OUTFLOW/FRONTAL BOUNDARY EXTENDING EAST-WEST
ACROSS SOUTHERN WISCONSIN (GENERALLY FROM SHEBOYGAN TO WISCONSIN
DELLS). AS LOW-LEVEL FLOW INCREASES OVER ILLINOIS, CONVERGENCE
ALONG THIS BOUNDARY COULD RESULT IN ADDITIONAL CONVECTION
DEVELOPING IN SOUTHERN/SOUTHEASTERN WISCONSIN OUT AHEAD OF THE
ONGOING QUASI-LINEAR COMPLEX. THIS WILL INCREASE POTENTIAL FOR
TRAINING/MERGERS AND PROLONGED RAINFALL RATES IN AREAS THAT HAVE
ALREADY EXPERIENCED 1-4 INCHES OF RAINFALL YESTERDAY NEAR/NORTH
AND WEST OF MILWAUKEE AND ACROSS FAR NORTHERN ILLINOIS. FFGS ARE
LESS THAN 1 INCH/HR IN SOME SPOTS AND COULD READILY BE EXCEEDED
WHERE MERGERS TAKE PLACE. FLASH FLOODING IS LIKELY - ESPECIALLY
IN SENSITIVE AREAS THAT RECEIVED RAINFALL/RUNOFF ISSUES LATE
YESTERDAY AND EARLY TODAY.
COOK
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...ARX...DVN...GRB...LOT...MKX...
ATTN...RFC...MSR...NWC...
LAT...LON 44558947 44408783 43208786 42008773 41548866
41449051 42319153 43979095
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