Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Sun Jul 27 2025 22:49:21

AWUS01 KWNH 272249
FFGMPD
WIZ000-MNZ000-IAZ000-SDZ000-NDZ000-280448-

Mesoscale Precipitation Discussion 0813
NWS Weather Prediction Center College Park MD
648 PM EDT Sun Jul 27 2025

Areas affected...central/southern Minnesota, eastern South Dakota

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

Valid 272248Z - 280448Z

Summary...Intense convection has shown a tendency for
backbuilding/localized training and areas of 2-2.5 inch/hr rain
rates so far this afternoon.  These trends are likely to continue
through 05Z or so while translating southward across the
discussion area, prompting instances of flash flooding.

Discussion...Intense convection has evolved into a cluster of
storms over west-central Minnesota recently, with a lead bowing
segment approaching Willmar, MN and upstream convection extending
from Willmar west to near Watertown, SD.  The upstream storms are
likely taking advantage of very steep lapse rates aloft (8.5C/km,
enabling heavy rainfall and strong downdrafts despite likely being
slightly elevated behind the cold pool produced by the lead
activity.  The orientation of this convective cluster (with storm
motions parallel to mean west-southwesterly flow aloft) favors
backbuilding of this complex into eastern South Dakota.  The
orientation will also favor local training/repeating and areas of
2+ inch/hr rain rates - especially given the abundantly moist
airmass supporting convection (1.75+ inch PW values).=20

These convective trends are expected to continue, with
backbuilding occurring across eastern SD and western MN along with
a slow southward translation of the overall complex.  Areal
coverage of the heaviest rainfall (i.e., 2+ inches/hr) should
remain steady or even increase at times as the complex migrates
southeastward.  These rates should readily exceed FFG thresholds
across the region (in the 1.5 inch/hr range) and promote excessive
runoff.  Flash flooding is likely in this scenario.

Cook

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!-i7KH8PUCew7T35oG7G-LflJQEFatRrLVzL5PkigYrd3QasZJZCFUfeseL9OhJQCuxzt=
3aMLr8kVfUwBghCls6nxMkM$  for graphic product...

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

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

LAT...LON   46499520 46119337 44779209 43729224 43189637=20
            43259830 44349863 45369838 45899757=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to
https://lists.illinois.edu and use the "Unsubscribe" link.  Otherwise email
Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

.