Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Sat Oct 11 2025 01:53:51

AWUS01 KWNH 110153
FFGMPD
AZZ000-UTZ000-NVZ000-CAZ000-110552-

Mesoscale Precipitation Discussion 1180
NWS Weather Prediction Center College Park MD
953 PM EDT Fri Oct 10 2025

Areas affected...southern Nevada, northwestern Arizona, southern
Utah, and far southeastern California

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

Valid 110152Z - 110552Z

Summary...Flash flooding remains likely across the discussion
area, with locally significant impacts noted near the Las Vegas
area.

Discussion...Scattered convection continues to migrate
northeastward along an axis from near Las Vegas metro
northeastward to near St. George, UT.  The cells remain embedded
in an environment characterized by abundant moisture 1-1.75 inch
PW values and sufficient surface-based instability for robust
updrafts (1000 J/kg SBCAPE).  Despite appreciable cell motions
(around 20-30 knots), these cells were producing areas of 0.5-0.75
inch/hr rain rates - enough to prompt local flash flood
occurrences near the Las Vegas metro area.  Localized training is
also aiding in promoting higher rain rates on a localized basis.

The ongoing scenario for flash flooding should continue for at
least a few more hours.  Low-level southerly advection beneath an
expansive rain shield across the CA/AZ border region (Lower
Colorado River) has stabilized the airmass in that area, and some
of this stable air may work into the discussion area from the
south.  This stabilization, combined with nocturnal boundary layer
cooling, should result in a gradual weakening trend with most
convection through 06Z/11p PDT.  Despite the anticipated weakening
trend, the overall synoptic environment (with forcing from
Priscilla's remnants to the south and a larger-scale upper trough
near northwestern California) may continue to favor isolated
convection (and localized flash flooding) where surface-based
instability remains.

Cook

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!7Jdk6OFcssdUL7VS0etkLp9eFcyqu60lBp3b6XIlLWIh9tEK6kdMQ5NReK5L-dQaWucF=
YG37iFyInTAiKcPtjCcDujg$  for graphic product...

ATTN...WFO...FGZ...LKN...SLC...VEF...

ATTN...RFC...RSA...STR...NWC...

LAT...LON   39071213 38351111 36601219 34201531 35791688=20
            37251612 38791414=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)

.