824
AWUS01 KWNH 311817
FFGMPD
TXZ000-NMZ000-AZZ000-010015-

Mesoscale Precipitation Discussion 1040
NWS Weather Prediction Center College Park MD
216 PM EDT Sun Aug 31 2025

Areas affected...far western TX into central to southwestern NM
and southeastern AZ

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

Valid 311815Z - 010015Z

SUMMARY...Thunderstorms will pose an isolated to scattered flash
flood threat across portions of far western TX into central to
southwestern NM and southeastern AZ through 00Z. Storms should be
disorganized in nature, but some slow movement and brief training
will carry a threat for 1-2 in/hr rain rates.

DISCUSSION...Visible satellite and radar imagery at 18Z showed a
gradual uptick in the coverage of thunderstorms, tied to the
diurnal cycle, over the southwestern quadrant of NM. Mostly clear
skies and anomalous moisture (12Z EPZ sounding with a PW of 1.3
inches, just above the 90th percentile for the end of August) was
contributing to a bubble of higher instability from near El Paso
into southwestern NM with 500 to 1500+ J/kg MLCAPE shown on the
18Z SPC mesoanalysis page. Moisture values were closer to average
for northern NM and into western AZ.

A 700-500 mb ridge was centered over the AZ/NM border with
easterly low level flow located from far western TX into southern
NM and this pattern will maintain through the late evening. A
small region of weak deeper layer mean winds was located over
south-central TX with (<10 kt 0-6 km) with 10-15 kt located
elsewhere. Continued heating and moisture advection into
southeastern AZ should allow for an expansion of instability with
500-1500 J/kg becoming widespread across southwestern NM into
southeastern AZ by 21-00Z. Low level easterly winds should cause
an increase in low level moisture and instability into
southeastern AZ by late this afternoon with thunderstorms either
moving into or developing over southeastern AZ. Some thunderstorms
will carry the potential for brief training along with slow
movement, supportive of 1-2 in/hr rain rates. At least an isolated
threat of flash flooding may continue beyond 00Z within lingering
instability but the flash flood threat is expected to begin to
wane after sunset.

Otto

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

ATTN...WFO...ABQ...EPZ...FGZ...TWC...

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

LAT...LON   34840748 34660549 33920502 32410525 31410603
            31320750 31030917 31341101 33500982 34340905
            34670834