892
AWUS01 KWNH 161151
FFGMPD
AZZ000-161400-

Mesoscale Precipitation Discussion 0706
NWS Weather Prediction Center College Park MD
750 AM EDT Wed Jul 16 2025

Areas affected...central/southern Arizona

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

Valid 161150Z - 161400Z

Summary...Isolated showers and thunderstorms are migrating slowly
westward within an abundantly moist airmass across the discussion
area.  Flash flooding is possible in typical low spots and
terrain-favored areas.

Discussion...A mid-level vorticity maximum was fostering deep
convective development this morning along an axis from
terrain-favored areas near Prescott south-southeastward to near
Tucson.  The storms are in a very moist environment, with PW
values nearing 1.75 inches and surface-based CAPE values exceeding
500 J/kg.  Wind fields aloft are fairly weak, contributing to
modest/erratic storm motions.  A recent band of convection just
north of Tuscon has exhibited slightly better organization for
training and rain rates near 1 inch/hr that were threatening local
FFGs in the area.

Ongoing trends should continue for at least another 2-3 hours (and
beyond) as the lingering MCV favorably interacts with
surface-based instability across the region.  Spots of 0.5-1.0
inch/hr rain rates are expected to contribute to a localized flash
flood risk in typical terrain-favored low spots.

Cook

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

ATTN...WFO...FGZ...PSR...TWC...

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

LAT...LON   34491218 33901092 32951037 32191021 31421090
            31971215 32891286 34301299