Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Wed Aug 06 2025 04:25:08

AWUS01 KWNH 060425
FFGMPD
MNZ000-IAZ000-NEZ000-SDZ000-NDZ000-061022-

Mesoscale Precipitation Discussion 0876
NWS Weather Prediction Center College Park MD
1224 AM EDT Wed Aug 06 2025

Areas affected...eastern South Dakota, southwestern Minnesota,
northwestern Iowa, northeastern Nebraska

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

Valid 060422Z - 061022Z

Summary...A mature convective complex will continue to produce
heavy rainfall while migrating southward through the discussion
area over the next six hours.  Flash flooding is possible.

Discussion...MRMS-estimated rain rates of 1-1.5 inches/hr continue
to be observed with a mature convective complex, which currently
extends from near Watertown, SD to just northeast of Pierre, SD.=20
The complex was propagating southward along an moist/unstable
axis, with 8C/km mid-level lapse rates and upper 60s F surface
dewpoints contributing to both 1500 J/kg MLCAPE and 1.5 inch PW
values.  The rightward movement relative to mean flow aloft has
enabled areas of localized training on the west side of the
complex, while isolated cells out ahead of the complex (along the
SD/MN border) have contributed to occasional cell mergers and
prolonging of heavy rainfall rates.  The overall slow movement of
the complex has also enabled rain rates to remain relatively high
at times (above 1 inch/hr).

Convective trends are expected to continue with this complex over
at least the next 4-5 hours.  The complex will continue to produce
spots of 1-2 inch/hr rain rates while migrating over areas of FFG
thresholds in the 1.5 inch/hr range, contributing to local
exceedance and occasional excessive runoff.  Later tonight, models
suggest that the complex may begin to weaken as it makes steady
progress toward a stout mid/upper ridge centered over Nebraska.=20
General consensus (per 00Z HREF) is that the complex should
continue to provide a heavy rain/flash flood threat at least
through northwestern Iowa and the Sioux City area through 09Z/4am
CDT, which seems reasonable given observed convective trends.

Cook

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!_e12L8QFI3DN16ZUDJcPscFobIaJcZi_zbPOBSLWI8RYX32MNwbEeVCWL_rDyGXF1dJv=
srFf8CdNqQYP9PPbb6V9ESU$  for graphic product...

ATTN...WFO...ABR...DMX...FGF...FSD...LBF...MPX...OAX...

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

LAT...LON   45959769 45919594 43849417 41849441 41309658=20
            42189880 44499977 45309974=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)

.