515
AWUS01 KWNH 171201
FFGMPD
MNZ000-IAZ000-SDZ000-NDZ000-171700-

Mesoscale Precipitation Discussion 0951
NWS Weather Prediction Center College Park MD
800 AM EDT Sun Aug 17 2025

Areas affected...Northeast SD...Southeast ND...West-Central to
Southern MN...Far Northern IA

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

Valid 171200Z - 171700Z

SUMMARY...Additional heavy showers and thunderstorms this morning
will continue to foster areas of flash flooding.

DISCUSSION...The early-morning GOES-E IR satellite imagery along
with radar shows a fairly organized axis of locally training
showers and thunderstorms impacting southern MN. This convection
is focused generally along and just north of a stationary front
draped west to east across the Upper Midwest.

MUCAPE values of 2000+ J/kg remain in place along this boundary
which in conjunction with a relatively modest southwest 20 to 30
kt low-level jet interacting with it should favor renewed rounds
of heavy showers and thunderstorms. This activity will continue to
be capable of training over the same area going through at least
the mid to late-morning hours given alignment that is nearly
parallel to the deeper layer steering flow. Some southward advance
of this activity into far northern IA is also possible given the
influence of the convectively enhanced cold pool close to the
MN/IA border.

Additional areas of heavy showers and thunderstorms will also be a
concern upstream over parts of northeast SD and southeast ND as an
upstream forward propagating MCS arrives and interacts with the
aforementioned front while fostering somewhat stronger warm air
advection out ahead of it. However, this activity at least by late
this morning should begin to gradually weaken as it approaches
west-central MN.

Rainfall rates with all of the stronger and more organized cells
in the short-term will still be capable of reaching 1.5 to 2.5
inches/hour which is being supported by the instability and a
corridor of 1.75+ inch PWs.

Additional rainfall totals as high as 3 to 5 inches will be
possible, and especially over southern MN where some of the most
organized convective activity is occurring. The latest HRRR and
WoFS guidance supports these totals at least locally as well.

Given the ongoing areas of flash flooding locally, and with these
additional rains, more areas of flash flooding are expected going
through at least the mid to late morning hours.

Orrison

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

ATTN...WFO...ABR...ARX...BIS...DMX...FGF...FSD...MPX...

ATTN...RFC...KRF...MSR...NWC...

LAT...LON   47399736 47029653 45619526 44849413 44129220
            43509139 42869167 42889342 43409578 44189741
            45169862 46319889 47179848