A north to south oriented cluster of severe thunderstorms is now about 25 to 35 miles west of Maverick and Webb counties in the Edwards Plateau. The storms are moving east at 20 to 30 MPH and are expected to move into the aforementioned counties around 3 AM. A severe thunderstorm watch is now in effect for South Texas, the Edwards Plateau, the Coastal Bend, and the Coastal Plains until 9 AM. Eagle Pass, Laredo, Zapata, Freer, Corpus Christi, Victoria, and Hallettsville are a few towns included in this watch.

Severe Thunderstorm Watch Number 40
NWS Storm Prediction Center Norman OK
150 AM CDT Sun Apr 7 2019

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
South central Texas
Coastal Waters

* Effective this Sunday morning from 150 AM until 900 AM CDT.

* Primary threats include…
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
A tornado or two possible

SUMMARY…A cluster of thunderstorms over northeast Mexico will move
across the Rio Grande into south Texas through the early morning
hours, and the storms will become more organized with time. The
storm environment will initially favor large hail as the main threat
with embedded supercells, but damaging winds will become more of a
threat as the storms grow into a bowing line. An isolated tornado
or two cannot be ruled out with embedded supercell or mesovortex
circulations.

05Z HRRR Simulated Weather Radar from 3 AM to 5 PM today. This is only a simulation, but is useful for general timing purposes.

The strongest storms over the next few hours may be capable of producing very large hail and localized damaging wind gusts up to 70 MPH. As the organize of the squall line/storm cluster increases toward 5-6 AM we’ll likely see a ‘bowing’ structure develop. That’s when we’re going to see an enhanced threat of damaging winds develop along with the potential of brief spin-up tornadoes. Hail will continue to remain a threat along with heavy rainfall. I do have some concern that we may see localized, but significant straight-line winds in a corridor from Laredo to Corpus Christi in the next several hours as the bow echo organizes. Any hail that occurs would be wind-driven and all that more dangerous.

We’ll see the squall line begin developing farther north toward sunrise and thereafter as storms begin impacting the Coastal Plains and eventually Southeast Texas. The strongest storms will continue to be capable of producing damaging straight-line winds, hail, brief tornadoes, and heavy rainfall. I expect additional severe weather watches will be issued later this morning as the squall line progresses to the east.