Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Tue Aug 01 2023 00:42:48

AWUS01 KWNH 010042
FFGMPD
AZZ000-UTZ000-NVZ000-CAZ000-010600-

Mesoscale Precipitation Discussion 0822
NWS Weather Prediction Center College Park MD
842 PM EDT Mon Jul 31 2023

Areas affected...northwestern AZ into southeastern NV and
southwestern UT

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

Valid 010041Z - 010600Z

SUMMARY...A threat for flash flooding will linger for another few
hours before likely diminishing across northwestern AZ into
southeastern NV and southwestern UT by 06Z. Rainfall rates of 1 to
2 inches in ~30 minutes will be possible on a localized basis.

DISCUSSION...GOES-18 visible satellite imagery and surface
observations showed ongoing thunderstorms with related cold pools
over the northwestern quadrant of AZ into southeastern NV, along
with scattered activity in southwestern UT. An eastward
progressing outflow boundary was noted in southern Clark County,
NV and a larger south and westward progressing outflow boundary
was analyzed in western AZ. The environment ahead of these
outflows was estimated to contain pockets of MLCAPE between
500-1000 J/kg along with precipitable water values that ranged
between 1.2 and 1.6 inches (00Z SPC mesoanalysis data).

The broader scale pattern suggests that overall storm movement
will be toward the NNW, around the western edge of a large scale
ridge centered over the southern High Plains. However, a weakness
in the deeper-layer mean flow exists over the tri-state region of
NV/UT/AZ with 850-300 mb mean layer winds of ~10 kt or less.
Outflow boundary interactions will aid new updraft development but
some storm motions will be slow given the weak deeper-layer winds,
with thermodynamic parameters supporting continued rainfall rates
of 1 to 2 inches in approximately 30 minutes. While coverage of
these higher rates should be somewhat isolated, at least a
localized flash flood threat will continue for another 2-3 hours
across northwestern AZ into southwestern UT and southeastern NV,
before expected weakening with the loss of daytime
heating/instability prior to 06Z.

Otto

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!8VDteCZ_542mqIDU-hAgb9SdPGLAGlNetuIfkJq_eBwLsohjBy_Ap5SJOwbufBrpYOaY=
PsDKp-JQVOtPXIzdx0O5fEY$  for graphic product...

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

ATTN...RFC...CBRFC...CNRFC...NWC...

LAT...LON   38301446 38251401 37971350 37291302 36521274=20
            35621249 35041198 34591192 34241236 34181352=20
            34431437 35141514 36181579 37381580 37971528=20
=20=20=20=20=20=20=20=20=20=20=20=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 3.14-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

.