277
AWUS01 KWNH 102235
FFGMPD
NMZ000-AZZ000-CAZ000-110330-

Mesoscale Precipitation Discussion 1179
NWS Weather Prediction Center College Park MD
634 PM EDT Fri Oct 10 2025

Areas affected...lower CO Valley into central/northeastern AZ and
northwestern NM

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

Valid 102230Z - 110330Z

Summary...Isolated to widely scattered areas of flash flooding
will be possible from the lower CO River Valley across central AZ
into northwestern NM through 04Z. Hourly rainfall of 0.5 to 1.0
inches is likely within stronger cores and isolated hourly totals
in excess of 1 inch will be possible.

Discussion...GOES West water vapor and OSPO ALPW imagery at 22Z
showed mid to upper level moisture from Post-T.C. Priscilla
streaming northeastward across the northern Baja Peninsula/Gulf of
California. Regional radar imagery showed a few stronger
reflectivity cores moving northward from Mexico into southeastern
CA and southwestern AZ, co-located with the upper level moisture
plume advancing into the region. Farther north, a broken SW to NE
axis of showers/thunderstorms extended from southwestern AZ into
northeastern AZ, along a remnant differential heating boundary and
along the White and San Francisco Mountains. Despite the highly
anomalous moisture plume in place across the entire Southwest
region, instability has been rather fragmented due to extensive
cloud cover limiting the coverage of higher rainfall rates up
until this point.

However, given the pockets of relatively higher MLCAPE that exist,
according to 22Z SPC mesoanalysis data, some locally higher
rainfall rates can be expected over the next 3-5 hours. 22Z SPC
mesoanalysis showed 500-1000 J/kg over portions of eastern AZ into
northwestern NM and into southwestern AZ, albeit with varying
degrees of inhibition. As the mid and upper level energy and
moisture plume from Priscilla continues to advance downstream
across the Southwest, the potential for increased rainfall
efficiency will exist within low level axes of confluence. These
axes of confluence will occasionally align with the deeper layer
mean steering flow from the SW, supporting repeating and training
of heavy rain cores. Isolated to widely scattered hourly rainfall
of 0.5 to 1.5 inches will be possible, generating possible flash
flooding, especially if overlap occurs with an axis of 1 to 3+
inches which has fallen over the past 24 hours from near Phoenix,
north-northeastward across I-40. In terms of coverage, if recent
WoFS cycles are any indication, 6-hr probabilities of exceeding 1
inch are less than 40 percent and quite isolated across AZ into
northwestern NM.

Otto

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

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

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

LAT...LON   36220988 36120807 35090798 34030943 32581118
            32061270 32181445 32741528 34131506 35341290