AWUS01 KWNH 151138
FFGMPD
TXZ000-151607-

Mesoscale Precipitation Discussion 0696
NWS Weather Prediction Center College Park MD
738 AM EDT Tue Jul 15 2025

Areas affected...South Central Texas

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

Valid 151137Z - 151607Z

Summary...Low confidence flash flooding scenario continues across
South-Central Texas. Localized 2-3" rainfall amounts atop
sensitive grounds within the highlighted area could drive
additional flash flooding through at least 16z.

Discussion...Over the last six hours, a nearly stationary complex
of thunderstorms over South-Central Texas has resulted in
estimated rainfall totals of 2-5" and several reports of flash
flooding in Real and Uvalde County. Convection with embedded
2-2.5"/hour rainfall rates has exhibited periods of training and
backbuilding on the eastern and western fringes of the complex.

As suggested by these efficient rates, the environment remains
conducive for effective warm rain production, with 1.9-2.1" PWATs
noted per recent mesoanalysis data. A west-east oriented
instability gradient is also noted -- separating negatively
buoyant air from uncapped 1000-2000 J/kg MLCAPE in the eastern
side of the gradient. Going forward, the slow moving forcing (MCV
and larger scale vorticity max) could maintain the ongoing
activity, while driving additional development which could
backbuild as the regime results in northerly Corfidi vectors
partially directed into the minimally capped, unstable air. Recent
runs of the HRRR suggest localized 2-3" amounts are possible
through 16-17Z which could rive additional instances of flash
flooding in light of ongoing impacts and general sensitivity of
the region.

Asherman

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

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

LAT...LON 31329943 30629850 29449857 28789917 28409995
28600052 29490076 30520130 31210066

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AWUS01 KWNH 081237
FFGMPD
TXZ000-081700-

Mesoscale Precipitation Discussion 0050
NWS Weather Prediction Center College Park MD
736 AM EST Sun Mar 08 2026

Areas affected...South-central Texas...

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

Valid 081235Z - 081700Z

SUMMARY...Slow moving cells capable of 1.75"/hr rates near the
Southern Balcones Escarpment/San Antonio Metro may pose localized
flash flooding concerns through mid-morning.

DISCUSSION...EWX RADAR and GOES-E 10.3um EIR continue to show
increasing coverage and cooling top/intensifying thunderstorms
across south-central Texas. Return weak southerly moisture flux
over the shallow cold front across Deep South Texas combined with
favorable divergence in the exit/diffluence of upper-level jet max
has enhanced scattered early morning shower activity into
deeper/broader updrafts capable of intense rainfall. VWP at EWX
combined with RAP analysis suggests a recent uptick in 850-700mb
flow to 15kts, but generally into the northern limit to the weak
isentropic ascent providing this additional convergence to
generate/expand convective activity. CIRA LPW shows sfc-850 and
850-700mb tight moisture gradient indicative of the shallow front
with values near .8-.9 and .5" respectively. The loading of this
1.5 to 1.75" total PWat into the cells has increased rainfall
efficiency to support 1.5-1.75"/hr rates, especially the broader
cell in Bexar county, which also shows solid suggestion of upwind redevelopment.

Deep layer steering driven mainly below 700mb has more of a slow
northward shift within broadly westerly flow, which is also nearly
parallel to the moisture/flux gradient. This may allow for short
periods of repeating to allow for hour plus duration or random training/repeating from upstream cells too. Spots of 2-3" are
possible in 1-2 hours though the mid-morning (through 15-17z)
until favorable jet divergence slides further eastward/weakens as
well.

Proximity to San Antonio Metro/broad urban center and Balcones
Escarpment will likely be the greatest driver of flash flooding
potential. Naturally low FFG along/north of the city with hourly
values between 1.5-2" are well within the potential of low-end
exceedance and suggestive of localized possible incident or two of
flash flooding, especially if combined with hydrophobic urban
setting, further compounding run-off potential. Though south of
the escarpment across the sandier Coastal Plain, FFG values
increase rapidly and therefore flooding risk would be considerably
lower, but still non-zero.

Gallina

ATTN...WFO...CRP...EWX...HGX...

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

LAT...LON 29999741 29759663 29389614 28909595 28569640
28349786 28389910 28619953 28919971 29259965
29649922 29919843

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