AWUS01 KWNH 150839
FFGMPD
NMZ000-AZZ000-151436-

Mesoscale Precipitation Discussion 1289
NWS Weather Prediction Center College Park MD
437 AM EDT Tue Sep 15 2026

Areas affected...portions of AZ

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

Valid 150836Z - 151436Z

Summary...Showers and thunderstorms are attempting to redevelop
over portions of central and eastern AZ.  Hourly rain amounts to
2" are possible, which could lead to flash flooding.

Discussion...The 00z HREF/REFS both indicated that after a period
of minimum that an early morning convective uptick could occur. 
That appears to be starting to happen as an upper level shortwave
moves into northwest AZ and interacts with a pool of 1000-2000
J/kg MU CAPE.  Effective bulk shear is 25 kts near and ahead of
the incoming shortwave.  Precipitable water values remain high,
close to 1" in portions of the Mogollon Rim and 1.75" in the Lower
Deserts.

While the 00z HREF/REFS both had this signal, they disagree as to
how strong of a heavy rain signal this becomes, which leads to
greater uncertainty than usual on the heavy rainfall potential. 
Should cell coverage continue to increase sufficiently, hourly
rain amounts to 2" would be possible where cells manage to
backbuild, train, or merge.  This could cause flash flooding in
urban areas, burn scars, dry washes/arroyos, and box/slot canyons.

Roth

ATTN...WFO...ABQ...EPZ...FGZ...PSR...TWC...VEF...

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

LAT...LON   35811002 35320815 34070817 33330874 32770911 
            32030979 31821030 31771094 32521214 34171338 
            34911316 35571181 

$$
--- MultiMail/DOS
 * Origin: capitolcityonline.net * KY, USA (618:250/10)