632
AWUS01 KWNH 310148
FFGMPD
AZZ000-310746-

Mesoscale Precipitation Discussion 1534
NWS Weather Prediction Center College Park MD
947 PM EDT Fri Oct 30 2026

Areas affected...central/eastern Arizona

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

Valid 310146Z - 310746Z

Summary...Isolated/spotty flash flood potential continues across
the discussion area for a few more hours.

Discussion...Scattered convection continues to produce up to 1
inch/hr rain rates in a cluster very near Phoenix Metro as of
0135Z (per MRMS).  The storms remain on the northern edge of a
pool of surface-based instability across much of the southern half
of AZ, with ascent resulting from 1) subtle orography with ~15kt
southerly 850mb flow impinging on central AZ terrain and 2)
mid-level troughing and embedded shortwaves approaching the area
from the Lower Colorado River Valley.  Cells continue to remain
isolated, which could be tied to drying aloft to the west.
Nevertheless, more established cells are right-moving, locally
backbuilding/merging, and remain supportive of 1 inch/hr rates at
times as they move east-northeastward.  These rates are
approaching local FFG.  Models/CAMS suggest that this potential
will continue on an isolated basis for several more hours before
nocturnal boundary layer cooling lessens instability and weakens
updraft strength.  Isolated/spotty flash flood threat will
continue for a few more hours -- perhaps through 06Z/10p Mountain
Time.

Cook

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

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

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

LAT...LON   35181111 34830995 33930921 32840933 32271058
            32641230 33411323 34611319 35121231