663
AWUS01 KWNH 152314
FFGMPD
TXZ000-160213-

Mesoscale Precipitation Discussion 1017
NWS Weather Prediction Center College Park MD
714 PM EDT Sun Sep 15 2024

Areas affected...Deep South Texas

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

Valid 152313Z - 160213Z

Summary...Lingering, isolated flash flood potential should remain
across Deep South Texas for at least another couple hours or so.

Discussion...A mature convective complex near
Brownsville/Harlingen was producing areas of 2-3 inch/hr rain
rates (estimated per MRMS) over the past hour.  Immediately
upstream/northwest of this complex, a lull in convection has been
noted likely due to widespread overturning and temporary low-level
stabilization.  Surface observations indicate very moist low-level
conditions in the wake of convection across the discussion area
(with upper 70s dewpoints), and 1000+ J/kg SBCAPE values remain in
place across the area.  Additional convection just south of the
Rio Grande seems persistent and slow-moving.  These cells could
drift back northward into the discussion area.  Meanwhile
mid-level vorticity over the region could result in additional
updrafts over the discussion area for the next few hours.  Any
additional rainfall would occur over locations of estimated 3-5
inch rainfall totals since 19Z.  Wet ground conditions/urbanized
areas could be sensitive to additional rainfall, and renewed flash
flooding in the wake of ongoing activity cannot be completely
ruled out.

This conditional flash flood risk could persist for another 2-3
hours at least.  Models continue to depict additional heavy
rainfall potential through the overnight hours (beyond 02Z) that
may 1) redevelop into populated areas of south Texas and 2)
require a new MPD issuance.

Cook

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

ATTN...WFO...BRO...

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

LAT...LON   27019930 26949846 26589733 26089691 25839712
            25879786 26209898 26599938