228
AWUS01 KWNH 202317
FFGMPD
TXZ000-NMZ000-AZZ000-NVZ000-210500-

Mesoscale Precipitation Discussion 0799
NWS Weather Prediction Center College Park MD
716 PM EDT Mon Jul 20 2026

Areas affected...Much of Arizona...Southwest New Mexico...El Paso,
Texas...

Concerning...Heavy rainfall...Flash flooding likely

Valid 202320Z - 210500Z

SUMMARY...Numerous clusters of thunderstorms with ample deep layer
moisture to support rates of 1.5"-1.75"/hr.  Slow forward motions
and potential for upstream random repeating may support localized
spots of 1.5-2.5".  As such, scattered incidents of localized
flash flooding remain likely through the early overnight period.

DISCUSSION...GOES-E WV suite shows core of stubborn closed low
remains over the western Panhandle of Texas; however, broadening
warming seen to the northeast and north in 6.9WV and increasing
AMVs shows increasing 35-50kt 3H jet that is helping to roll the
vorticity center westward in the last few hours as the larger
scale ridge builds southeast into the southern Central Plains.
This strengthening jet is oriented favorably for left exit
divergence across much of the Mogollon Rim into the Black
Mountains of Southwest NM.  As such, mid-level winds have
responded to tighten 700mb trough axis through the Rim as well
with northeasterly flow at 500mb providing solid deeper layer
convergence.

In the lower levels, there remains a broad conditionally unstable
air mass with a broad 1000-2000 J/kg of MLCAPE from far NW Arizona
into Southwest NM.  As such, recent GOES-E 10.3um and Visible
imagery shows a broader overturning and rapid cooling especially
east of Gila county from 35N to the Mexican border.  While deep
layer moisture is slightly reduced from prior days across SE AZ
into SW NM, surface Tds in the low 60s and pockets of 7-9 degrees
C Tds at 700mb are injected by stronger 15-25kts flow at cloud
base.  As such, rain rates are slightly increased to 1.5-1.75"/hr.
  Animated imagery shows leading edge of convection along the
Mogollon Rim to Yavapai to E Gila to Cochise, though a secondary
band across the San Francisco Plateau to S Navajo to Catron and
Dona Ana counties in NM, remain suggestive of potential for random
intersection/repeating of heavier cores that may result in
localized 2-2.5" totals through the early overnight period.  This
is likely to induce localized but scattered incidents of flash
flooding, mainly along the upper-stretches of the higher terrain
(Mogollon Rim and NM Mtns).

At this time, strong convergence and upslope flow out of the
central Valley and Sonoran Desert may slow southwestward
propagation, but with time some better organized clusters could
translate further southwest (central AZ) and west (S AZ) into low
elevations, sub-cloud inflow while moist, may not be sufficiently
unstable to maintain the convection, though isolated cells could
reach more populated locations after dark, so an isolated incident
of flash flooding downslope may still be possible into the
overnight period.

Gallina

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

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

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

LAT...LON   36591228 36021057 34720856 33980680 32650603
            32070607 31770634 31620671 31670733 31650797
            31240815 31191015 31521144 32441194 32971200
            33631232 34331294 34841360 35181404 35731433
            36381400 36581336