958
AWUS01 KWNH 150508
FFGMPD
TXZ000-151100-

Mesoscale Precipitation Discussion 0692
NWS Weather Prediction Center College Park MD
108 AM EDT Tue Jul 15 2025

Areas affected...Southern Edwards Plateau...Rio Grande Valley of
South-Central Texas...

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

Valid 150510Z - 151100Z

SUMMARY...Low confidence, but potentially additional 2-4" over
saturated/sensitive grounds again tonight.  Back-building/training
would be the driver to localized possible flash flooding overnight.

DISCUSSION...KDFX RADAR and GOES-E SWIR animations show a strong
roll cloud/outflow boundary surging northward through the Rio
Grande Valley into the Southern Edwards Plateau given slightly
more mid to upper-level dry air relative to prior days.  However,
the parent MCV remains further south over N Nuevo Leon and there
is a remaining mid-level vorticity center across the Lower Pecos
Valley that remains a pivot along the stubborn positive tilt
trough back across the Red River and eventually the Lower Ohio
River Valley.  This convection is also along the leading edge of
the return moisture up the Rio Grande Valley with VWP noting a
steady increase and alignment of 925-700mb flow along the river at
20-30kts, providing solid moisture flux with total PWats up to 2".

As the surge slowly veers toward the mid-level vorticity center in
the Pecos Valley and is reinforced from the south, the orientation
of the eastern side of the outflow boundary is becoming fairly
stationary west to east, but even slightly backed low-level flow
will support stronger upwind convergence and potential for
back-building and slow northeastward expansion given WAA regime.
This is a similar evolution to overnight last night; though value
of moisture are slightly lower and there is a loss of stronger SW
to NE oriented boundary to the shortwave to the northeast (now in
OK not Northwest TX).  Still, there are sufficient models
including the RRFS and ARW suite that support this evolution with
2"/hr rates and within the training bands potentially small areal
totals of 2-4" across already saturated soils (where FFG values
are less than 1.5"/hr and less than 2"/3hs.  These rates over this
hydrologic environment may suggest a likely FF scenario...however,
with reduced moisture values and much lower confidence, will only
carry the flash flooding possible tag on this MPD.

Gallina

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

ATTN...WFO...EWX...SJT...

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

LAT...LON   30840023 30759961 30319912 29569925 29089950
            28579993 28670051 29130090 29530109 30080120
            30610096