Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Tue Sep 23 2025 05:19:43

AWUS01 KWNH 230519
FFGMPD
OKZ000-KSZ000-231030-

Mesoscale Precipitation Discussion 1122
NWS Weather Prediction Center College Park MD
118 AM EDT Tue Sep 23 2025

Areas affected...Southern Kansas...Northern Oklahoma...

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

Valid 230515Z - 231030Z

SUMMARY...Efficient, intense, quick-hitting thunderstorms capable
of sub-hourly totals of 1-2" and totals to 3"+ pose localized
flash flooding concerns through overnight period.

DISCUSSION...GOES-E 10.3um IR loop shows fast moving clusters of
thunderstorms with isolated overshooting tops cooling to -80C
across SW KS into NW OK.  RADAR mosaic denotes the broadening arch
of these cells in advance of a fast moving southern stream
shortwave features exiting the OK Panhandle.  The arch is an
alignment of mid-level DPVA ascent and strong confluent boundary
layer convergence of southwesterly flow off the high terrain and
broadening, but strengthening LLJ responding to the much larger
scale height-falls and organization of the closed low across the
Central Rockies.   VWP and RAP analysis shows the strong deep
layer WAA veering with strengthening 30 to 35kt flow through
925-850mb convergent on this arch.  Low 70s Tds at the surface,
60s through 850mb and even low 40s at 700mb shows convergence
though depth very well within animation of the CIRA LPW resulting
in 1.75" total PWats, but very strong deep layer flux convergence.
 MLCAPEs over 3000 J/kg combined with strength of flux is
resulting in high rainfall generation/efficiency for these
expanding clusters.=20

Limiting factors are the strength of the flow, is resulting in
very quick cell motions of 30-40kts, limiting residency.  However,
regional RADAR mosaic denotes the updrafts are broadening along
the length of the mean flow, increasing duration ever so slightly.
 Currently, KDDC/KVNX suggest hourly estimates of 1-1.5", though
are steadily increasing given overall increase of deep layer
moisture.  03z HRRR suggests peak of 1.5-2" in 15 minutes across
south-central KS between 06-08z, which does not seem implausible
and aligns with 00z HREF 2"/hr probability of 40%.  As such,
localized totals of 2-3" in 1-2 hours may result in localized
flash flooding conditions, especially given most areas within the
area of concern have 1hr FFG values at or below 2", with some
areas of south-central KS into northeast OK, slightly reduced
further to below 1.5", given recent rainfall.  Still, the overall
speed of cells may result in a highly variant rainfall pattern
resulting in scattered incidents of flash flooding overnight.=20

Gallina

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!_yMbKuqR-e7d7sKqPNw_G-AL1eLFqdnLf-d_vov8B6wRoUxvkp5L8n8GikXRHdVpSuvJ=
Wn5O2RWDIQbt_MG4Xb8sd5E$  for graphic product...

ATTN...WFO...DDC...ICT...OUN...TSA...

ATTN...RFC...TUA...NWC...

LAT...LON   38229763 37959602 37539537 36979526 36529543=20
            36229603 36149709 36199823 36349917 36979966=20
            37519987 38019910=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)

.