Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Wed Jul 16 2025 02:38:04

AWUS01 KWNH 160237
FFGMPD
MNZ000-IAZ000-SDZ000-160800-

Mesoscale Precipitation Discussion 0704
NWS Weather Prediction Center College Park MD
1036 PM EDT Tue Jul 15 2025

Areas affected...Eastern SD...Southwest & South-central
MN...Northwest IA...

Concerning...Heavy rainfall...Flash flooding possible

Valid 160235Z - 160800Z

SUMMARY...Slow moving/stationary cells along the intersection of
the MCS and the frontal zone across S MN present the opportunity
for localized totals of 2-3.5" and possible flash flooding
conditions

DISCUSSION...Regional RADAR shows a strong bowing MCS across
southeast SD/northeast NEB moving into northwest IA; with a parent
shortwave center north of the MCV in northeast SD.  Additionally,
the cold pool/flanking line outflow from the exiting shortwave/MCS
in N WI has enhanced the surface front that connects up to the
aforementioned MCS in S MN.  While the bow is surging, winds
across the effective warm sector have been backing and
strengthening and starting to provide increasing convergence for
isentropic ascent across the frontal zone.  Convection along the
rotor of the MCS and along the effective occlusion of the bow and
the front will have slow, perhaps even stationary nature working
with ample moisture of 1.75-2" TPW and fairly conditionally
unstable air with MLCAPEs still at or above 2000 J/kg across
southwest to south-central MN.   Rates of 2"/hr may linger for 1-2
hours exhausting the available unstable air with new generation
shifting eastward along the frontal zone.   Spots of 2-3.5"/hr may
dot across the region (including near/southeast of the parent
shortwave in SD).  FFG values of 1.5-2"/hr and 2-3"/3hr may
locally be exceeded suggesting possible incidents of flash
flooding over the next 3-5 hours.

Further southeast, there is some suggestion that as the bow
continues to surge southeast and rear inflow jet strengthens;
there is suggestion the northern rotor of the MCS may
redevelop/intensify further south into NW IA, so have included it
within the MPD given similar slower, stalling cells along the
low-level shear interface expected across southwest MN.

Gallina

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!7OUftaQEe9zqD7znpH1X_7dPagn5DBSFZ4kufcoDAEXYg6UJ8wN80kYhtSr7Z9mKY7_w=
YfokSvn4kgmuC81y7W3WcLA$  for graphic product...

ATTN...WFO...ABR...DMX...FSD...MPX...

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

LAT...LON   45429687 45149469 45039311 44669289 43959330=20
            43299438 42209476 42409601 43109712 43959720=20
            45019775=20

=3D =3D =3D
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