Mesoscale Precipitation Discussion 0160
NWS Weather Prediction Center College Park MD
227 AM EDT Wed Apr 23 2025

Areas affected...portions of central Texas

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

Valid 230626Z - 231100Z

Summary...An eastward-moving convective complex is spreading
0.5-1.5 inch/hr rain rates across the Texas Hill Country
currently.  On its present track, this complex could reach the
Austin/San Antonio Metropolitan Corridor and pose a risk of
isolated, urban flash flooding in the next couple hours or so
(through 09Z/4am CDT).

Discussion...Convection across southwest Texas and the Hill
Country has managed to grow upscale into an eastward-moving
complex, with persistence well beyond that indicated by most prior
model guidance.  This complex is being maintained by considerable
mid-level organization and a mature cold pool that continues to
propagate into a gradually more moist and unstable downstream
airmass (1.5 inch PW, 2000 J/kg MLCAPE).  The complex is currently
on the eastern edge of stronger low-level flow/shear, which lends
some uncertainty with regard to eastward persistence.  However,
recent NAM/RAP low-level wind fields are progged to increase
modestly across the discussion area through 09Z.  This, combined
with weak convective inhibition downstream suggests that heavier
downpours could make it into the Austin/San Antonio Metropolitan
Corridor by around 09Z/4am CDT or so.

If this complex can hold together, areas of 1-1.5 inch/hr rain
rates should affect urbanized areas and pose an isolated risk of
flash flooding.  This risk should mainly focus around urbanized
and low-lying/sensitive locations, as nearby FFGs/soil moisture
profiles indicate less-sensitive ground conditions especially east
of the Austin/San Antonio areas.

Cook

ATTN...WFO...EWX...FWD...HGX...SJT...

ATTN...RFC...WGRFC...NWC...

LAT...LON   31239839 31089742 30189660 29279677 28809790
            29190010 29760095 31129922