880
AWUS01 KWNH 140152
FFGMPD
TXZ000-140750-

Mesoscale Precipitation Discussion 0677
NWS Weather Prediction Center College Park MD
950 PM EDT Sun Jul 13 2025

Areas affected...Portions of the TX Hill Country and South-Central
TX

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

Valid 140150Z - 140750Z

SUMMARY...Showers and thunderstorms may expand in coverage over
the next several hours. Very heavy rainfall rates and slow
cell-motions will be possible, and this may result in some areas
of flash flooding.

DISCUSSION...Early evening GOES-E IR satellite imagery along with
recent radar trends shows developing areas of showers and
thunderstorms across portions of south-central TX close to the Rio
Grande River. Some weak vort energy is appearing in satellite data
across northern Mexico which is slowly drifting off to the
northeast toward south-central TX.

An unstable airmass is pooled up across much of the Lower Rio
Grande Valley with moist southeast low-level flow in place, and a
moderate to strongly unstable boundary layer. MLCAPE values of
1500 to 2500+ J/kg are noted in the latest RAP analysis, and this
vort energy encroaching on south-central TX and at least some
portions of the TX Hill Country may support some expansion of
heavy shower and thunderstorm activity over the next several hours.

PWs across the region are very moist with values of 1.8 to 2.2
inches. This coupled with the instability should favor high
rainfall rates reaching as high as 2 to 3 inches/hour with any of
the stronger and more organized convective cells that do
materialize.

The latest hires model guidance is rather inconsistent on the
timing and placement of the heaviest rainfall potential going into
the overnight hours, but the ingredients are in place for some
expansion of the convective threat over the next several hours.

Some spotty rainfall totals going through 06Z (1AM CDT) may reach
3 to 5 inches. Some areas of flash flooding will be possible as a
result.

Orrison

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

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

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

LAT...LON   30230034 29969934 29199870 28039887 27669962
            28090028 28460050 29140085 29740150 30100135