Mesoscale Precipitation Discussion 1501
NWS Weather Prediction Center College Park MD
1111 PM EDT Thu Oct 15 2026

Areas affected...South-Central Texas

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

Valid 160310Z - 160900Z

Summary...A swath of heavy rainfall with embedded thunderstorms
may lead to some instances of flooding through the early morning
hours from the central Rio Grande to north-central Texas. The
heaviest rainfall and flash flood potential will be across
southern portions of the outlook area.

Discussion...Current Doppler radar imagery continues to indicate
widespread moderate to heavy rainfall with some stronger areas of
convection on the poleward side of a slowly advancing cold front,
with an anafrontal rainfall set-up. This is due to surface to 850
mb flow from the southeast being lifted over the frontal boundary,
in an environment of anomalous PWs for October with values in the
1.7 to 2.0 inch per recent SPC mesoanalysis. The mitigating factor
is the gradually waning instability parameters, generally at or
below 500 J/kg of mixed layer CAPE, highest near the Rio Grande.
Although the overall rainfall rates have been modest in most areas
this evening, the extended duration is increasing the ground
saturation and leading to increased run-off and flooding concerns.

The latest CAM guidance suite is indicating the potential for
scattered QPF maxima on the order of 1 to 3 inches through 9Z, and
potentially slightly higher in a few areas where convection is
most persistent. The highest values are likely to occur south of
the Interstate 10 corridor. There should be a gradual abatement
towards 9Z as instability wanes and overall forcing weakens.

Hamrick

ATTN...WFO...EWX...FWD...MAF...SJT...

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

LAT...LON   32519815 32329755 31779743 31229777 30259879
            29999912 29579962 29160020 28960074 29240113
            29620182 29390245 29600278 29960277 30350253
            30550227 30750175 31070071 31509993 31959930
            32399869