412
AWUS01 KWNH 230154
FFGMPD
COZ000-NMZ000-AZZ000-UTZ000-230745-

Mesoscale Precipitation Discussion 1517
NWS Weather Prediction Center College Park MD
953 PM EDT Thu Oct 22 2026

Areas affected...Northern AZ...Central and Southern UT...Southwest
CO

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

Valid 230153Z - 230745Z

SUMMARY...Scattered showers and thunderstorms may foster some
additional flash flooding concerns tonight.

DISCUSSION...The latest GOES-W WV suite shows a strong upper
trough/closed low over the Southwest U.S. gradually advancing
eastward. Satellite imagery shows the energy taking on a negative
tilt, and this enhanced forcing/divergence aloft associated with
the height falls along with steepening mid-level lapse rates will
continue to favor additional areas of scattered showers and
thunderstorms going through the overnight hours.

MUCAPE values are locally still over 500 J/kg, and there are still
some areas of favorable low to mid-level moisture convergence
which coupled with orographic ascent over the higher terrain
should support the convective threat lingering along with locally
heavy rainfall rates.

The latest radar shows some of the stronger and more organized
cells over areas of far northern AZ and into southern UT. Drier
mid-level air arriving across the region will tend to mitigate the
rainfall rates a bit, but some rainfall rates with the stronger
storms may still reach as high as 1 to 1.5 inches/hour.

Localized cell-training will remain possible, and this may yield
some additional storm totals of up to 2 inches. This may result in
areas of additional flash flooding, with the slot-canyon regions
and burn scar locations most susceptible to seeing these potential
flash flooding impacts. Some of the normally dry washes may also
see potential for runoff concerns.

Orrison

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

ATTN...WFO...ABQ...FGZ...GJT...SLC...VEF...

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

LAT...LON   40051093 39840951 39020827 37970784 37220854
            36140944 34531021 34281115 34921215 36621266
            37941269 39301222