016
AWUS01 KWNH 190125
FFGMPD
MIZ000-WIZ000-MNZ000-190602-

Mesoscale Precipitation Discussion 0463
NWS Weather Prediction Center College Park MD
925 PM EDT Tue Jun 18 2024

Areas affected...Portions of the Upper Midwest

Concerning...Heavy rainfall...Flash flooding likely

Valid 190124Z - 190602Z

Summary...Training bands of efficient showers and thunderstorms
continue this evening across parts of the Upper Midwest.
Additional flash flooding is expected as east-southeastward
through 6z.


Discussion...Radar across the Upper Midwest continues to track
southwest to northeast oriented bands of training showers and
thunderstorms which were slowly translating southeastward ahead of
a frontal wave. Rainfall production within this activity remains
quite prolific, with recent estimates out of KLDH highlighting
hourly rainfall rates of 2"/hr within the most intense convective
bands. This very efficient training activity led to numerous
reports of flash flooding across the region this afternoon, and
maximum ARI exceedences upwards of 200 years in parts of MN per
MRMS.

Recent SPC mesoanalysis estimates highlight a very favorable
environment for the maintenance and development of additional
convective bands. 2000-3000 J/KG of MUCAPE and PWATs of 1.9-2.0"
are noted within the warm sector, which will be fairly slow to
erode even as heating wanes given the very impressive southerly
moisture transport vectors in the 925-850 mb layer. The ejection
of the upper-trough across the Northern Tier will also maintain
plenty of divergent and diffluent flow aloft to maintain and
develop convective bands ahead of the front.

Accordingly, through 6Z continued training segments with a slow
southeastward translation are expected continue the flash flooding
threat across Minnesota, Wisconsin, and Iowa. This is reflected in
the 18z HREF EAS neighborhood probabilities, which maintain high
(40-50%) probabilities of exceeding an inch of rainfall through 6Z
along and ahead of the front, where local rainfall could eclipse
2-3". This will support additional instances of flash flooding in
light of saturated conditions from earlier and ongoing activity.

Asherman

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...ARX...DLH...GRB...MPX...MQT...

ATTN...RFC...NCRFC...NWC...

LAT...LON   48499015 47978920 47058905 46278932 45299035
            43799152 43559289 44079377 45329382 46929321
            48319158