AWUS01 KWNH 281801
FFGMPD
TXZ000-NMZ000-290000-

Mesoscale Precipitation Discussion 0818
NWS Weather Prediction Center College Park MD
200 PM EDT Mon Jul 28 2025

Areas affected...West Texas...Southern & Central NM

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

Valid 281800Z - 290000Z

SUMMARY...Developing thunderstorms within an increasingly moist
and unstable air-mass will produce torrential downpours over areas
with sensitive soils. Flash flooding is likely, especially in
complex terrain that includes the Davis Mountains, Sacramento
Mountains, and Gila National Forest.

DISCUSSION...A 500-700mb mean layer trough, which is the same
disturbance that tracked across the northern Gulf of Mexico late
last week, is currently over northern Mexico and directing its
rich moisture source up the Rio Grande Valley courtesy of
increasing SErly 850-700mb flow. This disturbance is playing a
large role in why most of the region has seen a spike in dew
points, rising to as much as 20-25F over the past 24 hours via
RTMA in central NM. Even just over the last 6-hours, surface
observations show the low-mid 60s dew points in West Texas have
now made their way into southeast New Mexico while at the same
time, MLCAPE is steadily increasing thanks to strong surface-based
heating. By mid-afternoon, as much as 1,000 J/kg of MLCAPE will be
at these storms disposal. This combination of increasing moisture
aloft, plus the destabilization of the boundary layer, is
prompting a field of agitated cumulus to form from the Davis
Mountains on north to the Sacramentos. NAEFS shows 850-700mb mean
specific humidity (g/kg) and PWs near 1.5" around the El Paso area
are above the 90th climatological percentile, and indicative of
the exceptional moisture content available for thunderstorms to
tap into this afternoon and evening.

Expect thunderstorms to flare up along the mountain ranges east of
the Rio Grande first, followed by areas farther west of the Rio
Grande beneath the lingering cirrus canopy closer to the Gila
National Forest not long afterwards. The Sacramento Mountains, and
the Ruidoso area in particular, remain very susceptible to flash
flooding and debris flows given their saturated and sensitive
soils. NASA SPoRT-LIS's 0-40cm soil moisture percentile show that
not only are the Sacramentos sporting saturated soils, but so are
parts of the Davis Mountains and the Gila National Forest where
soil moisture percentiles are above 80%. The Rio Grande Valley and
other nearby valleys west of El Paso are likely to see storms a
little later as outflows emanating from thunderstorms over the
mountains move into the valleys and help to initiate further
thunderstorm activity. With the kind of anomalous moisture and
modest instability present, maximum hourly rainfall rates up to
2"/hr are well within reach across a region whose 1-hr FFGs are
generally <1.5". Given these factors, flash flooding is likely
this afternoon and into this evening. Locally significant flash
flooding is possible in areas containing burn scars and highly
sensitive soils along complex terrain.

Mullinax

ATTN...WFO...ABQ...EPZ...MAF...

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

LAT...LON   34610668 34450582 33510487 31880439 31150382 
            30390335 29790308 29280298 28970324 29070406 
            29620473 30850586 31340710 31000831 31230894 
            32330898 33130891 34120855 34580764 

$$
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