250
AWUS01 KWNH 100143
FFGMPD
AZZ000-UTZ000-NVZ000-CAZ000-100541-

Mesoscale Precipitation Discussion 1175
NWS Weather Prediction Center College Park MD
942 PM EDT Thu Oct 09 2025

Areas affected...portions of the southwestern U.S.

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

Valid 100141Z - 100541Z

Summary...Scattered convection continues to produce isolated
backbuilding/training and a few spots of rain rates exceeding 0.5
inch/hr.  Flash flooding is possible on an isolated basis for the
next few hours (through 06Z/11p PDT).

Discussion...Scattered convection continues to drift northeastward
across a broad part of the Great Basin currently.
Stratiform/shallow convection has been noted in many areas,
although deeper convection with more focused training has resulted
in an extended period of 0.5 inch/hr rain rates near Pahrump, NV
and adjacent areas of southeastern California.  Convection in that
area is likely experiencing influence both from increased
mid-level moisture associated with Priscilla and weak mid-level
shortwave troughs related to a larger mid/upper wave west of
California.

Sufficient surface-based instability exists for convection to
continue occasionally backbuilding/training for a few more hours
on an isolated basis.  Areas of 0.5 inch/hr rain rates should
continue at times, with training resulting in local 1+ inch
rainfall totals.  Training axes like the one near Pahrump may
develop on an isolated basis across northwestern Arizona,
southeastern Nevada, and far southern Utah.  Farther south along
the Lower Colorado River Valley, weaker forcing should continue to
keep flash flood risk isolated along with somewhat weaker rain
rates.

The greatest risk of flash flooding over the next few hours should
remain focused across southern Nevada, southern Utah, and
northwestern Arizona through 06Z/11p.

...Please see www.wpc.ncep.noaa.gov for graphic product...

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

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

LAT...LON   38751243 37611100 35681166 33291308 33181548
            34651693 36601644 38201538