Flood risk South TX
From
Mike Powell@618:250/10 to
All on Mon Oct 5 08:45:28 2026
AWUS01 KWNH 051249
FFGMPD
TXZ000-051800-
Mesoscale Precipitation Discussion 1453
NWS Weather Prediction Center College Park MD
848 AM EDT Mon Oct 05 2026
Areas affected...Extreme Southern Tip of South Texas...
Concerning...Heavy rainfall...Flash flooding possible
Valid 051250Z - 051800Z
SUMMARY...Extremely narrow band of repeating/training showers with
embedded stronger thunderstorms capable of quick 2"/hr.
Possibility of additional 2-4" mainly along/just off coast.
DISCUSSION...Persistent tropical band of showers and occasional
embedded deeper convective cores remains in close proximity to the
far southern tip of Texas with little variation expected over the
early morning period. Aloft, a stronger tropical wave is
progressing through the Bay of Campeche into the Eastern Mexican
coast providing an outflow channel aloft with 30-50kts of flow,
weakly curved anticyclonically to further diffluence and broad
scale vertical ascent. The surface front continues to remain
fairly stationary and just off-shore, though there is a weak
surface to 850mb wave near 26.5N 96.5W but may not be drifting
southeasterly. Though due to curvature of the coast, confluence
remains solid enough and with deep layer moisture over 2.7",
rainfall efficiency capability will remain in enough proximity to
suggest 2"/hr rates would be possible with transient convective
cores if they develop. Gradient of instability with maximum of
1500 J/kg just a few miles off coast, even in a deeply saturated
profile suggests that vertical development may occur even with
typically weak convergence. As such the risk of excessive
rainfall capable of maintaining flooding or increasing to rapid
inundation flooding remains possible for the early morning through
afternoon; though current trends hint toward a weak lull, this may
change hour by hour and potential for 2-4" totals through 18z keep
potential for flash flooding possible.
Gallina
ATTN...WFO...BRO...
ATTN...RFC...FWR...NWC...
LAT...LON 26499731 26439718 26039708 25869718 25809735
25849756 25979761 26239752
$$
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* Origin: capitolcityonline.net * KY, USA (618:250/10)