SPC MD 2024

SPC MD 2024


Mesoscale Discussion 2024
NWS Storm Prediction Center Norman OK
0854 AM CDT Tue Aug 22 2023

Areas affected…Lower/Middle TX Coast into TX Coastal Plain

Concerning…Severe potential…Watch unlikely

Valid 221354Z – 221600Z

Probability of Watch Issuance…20 percent

SUMMARY…Isolated storms may become strong enough to produce a
tornado or two as Tropical Storm Harold continues eastward into the
Lower/Middle Texas Coast and Texas Coastal Plain.

DISCUSSION…Latest regional radar imagery shows the center of
Tropical Storm Harold is about 85 miles northeast of BRO (85 miles
southeast of CRP), moving westward at 16 kt. Robust low to mid-level
wind fields associated with this system continue to spread inland,
with the CRP VAD showing a large area of 50+ kt easterlies from 3 to
6 km AGL. These wind fields are fostering fast storm motion of due
west around 30-35 kt, with Bunkers storm-motion estimates just a bit
more northwesterly and slower. Current mesoanalysis estimates 0-1 km
storm-relative helicity values around 150 m2/s2 for much of the
Lower/Middle TX Coast.

As is typical in tropical scenarios, most storms appear to have
relatively shallow updrafts and short duration, limiting the ability
for updraft rotation and tornado production. That being said, any
updrafts that are able to persist and deepen, usually indicated by
the presence of lightning and more deviant northwestward storm
motion, could produce brief tornadoes. Current trends do not show
any convective bands with storms exhibiting these characteristics.
However, there is enough buoyancy in place to suggest this deepen
could happen quickly, particularly in areas where cloud breaks allow
for greater heating and/or higher theta-e closer to the center of
the system.

Current expectation is for isolated, short-lived nature of any
deeper convection to limit the need for a watch. Even so, convective
trends will be monitored closely.

..Mosier/Grams.. 08/22/2023

…Please see www.spc.noaa.gov for graphic product…


LAT…LON 26799749 26969830 28399833 29629750 29599622 29079529
28449620 27879701 26799749

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