Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Sat Jul 26 2025 22:54:13

AWUS01 KWNH 262254
FFGMPD
OHZ000-INZ000-ILZ000-MOZ000-270252-

Mesoscale Precipitation Discussion 0806
NWS Weather Prediction Center College Park MD
653 PM EDT Sat Jul 26 2025

Areas affected...central Illinois, northern/central Indiana,
western/northern Ohio, far northeastern Missouri

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

Valid 262252Z - 270252Z

Summary...Isolated flash flooding is possible as clusters of
thunderstorms move from west to east across the discussion area
through early evening.

Discussion...Scattered thunderstorms have been persistent across
the discussion area for much of the afternoon.  A few of these
storms have exhibited modest upscale growth into
forward-propagating clusters and linear segments.  The storms are
embedded in an abundantly moist, unstable airmass (2+ inch PW
values, 2000+ J/kg MLCAPE south of ongoing thunderstorm activity),
supporting efficient rainfall rates beneath persistent activity.=20
Cell mergers and occasional repeating has led to spots of
estimated 2+ inch/hr rain rates with this activity - most recently
northeast of Columbus, OH.

Storms are largely progressive amid 20+ kt westerly steering flow
aloft.  Additionally storms are outflow dominant due to weak
low-level shear.  Through the early evening, isolated spots of
1.5+ inch/hr rain rates are expected where cell mergers and
localized backbuilding can materialize.  These rain rates should
fall on relatively wet soils from prior rainfall, and FFGs are
generally lower than 1.5 inch/hr areawide (lowest across Ohio and
central Illinois).  These FFGs are likely to be exceeded in a few
spots, and localized areas of flash flooding cannot be ruled out.=20
Later this evening, models (particularly the HREF suite) suggest a
weakening trend coincident with a loss of surface
heating/low-level stabilization especially after around 02Z.  The
flash flood risk should also gradually wane after that timeframe.

Cook

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!-kc98H1ucOMC5PH8Phhg933jSQtblatXyVCHqIgeQz87zTzSh8AFKEeI4KOw1DorGvaB=
qLUrcP32qp8cbeKmiTyAW3M$  for graphic product...

ATTN...WFO...CLE...DVN...ILN...ILX...IND...IWX...LOT...LSX...
PBZ...RLX...

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

LAT...LON   41538445 41398238 41198143 40348116 39748157=20
            39438304 39818577 39768804 38849188 39919179=20
            40878902 41368685=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)

.