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WWUS20 KWNS 091921

SEL8

SPC WW 091921

TXZ000-100400-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 158

NWS Storm Prediction Center Norman OK

220 PM CDT Thu May 9 2019



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  South and South-Central Texas



* Effective this Thursday afternoon and evening from 220 PM until

  1100 PM CDT.



* Primary threats include...

  Scattered large hail likely with isolated very large hail events

    to 3 inches in diameter possible

  Scattered damaging winds and isolated significant gusts to 75

    mph possible

  A tornado or two possible



SUMMARY...Thunderstorms will continue to intensify this afternoon

along a southward-sagging front and additional boundaries across the

region, initially across south-central Texas and immediately near

the Rio Grande. A moist and very unstable environment, along with

moderately strong deep-layer shear, will support supercells capable

of very large hail. While low-level shear is not overly strong, a

tornado or two cannot be ruled in a high instability environment,

particularly in proximity to any surface boundary. With time, storms

should increase into additional parts of south Texas southward into

the Brush Country and/or move across the Rio Grande. A line of

storms could eventually evolve and accelerate eastward later this

evening.



The severe thunderstorm watch area is approximately along and 95

statute miles north and south of a line from 30 miles south

southwest of Del Rio TX to 55 miles southeast of San Antonio TX. For

a complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU8).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A Severe Thunderstorm Watch means conditions are

favorable for severe thunderstorms in and close to the watch area.

Persons in these areas should be on the lookout for threatening

weather conditions and listen for later statements and possible

warnings. Severe thunderstorms can and occasionally do produce

tornadoes.



&&



OTHER WATCH INFORMATION...CONTINUE...WW 157...



AVIATION...A few severe thunderstorms with hail surface and aloft to

3 inches. Extreme turbulence and surface wind gusts to 65 knots. A

few cumulonimbi with maximum tops to 550. Mean storm motion vector

28015.



...Guyer

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