Sunday, April 10, 2011

Severe Weather Update for Texas

The sun is setting so this is our last opportunity to use visible satellite imagery to tell us what's going on before dark.  The above visible satellite image, taken at 8pm CDT, shows a line of thunderstorms (and developing thunderstorms) extending from just north of the Big Bend, through the San Angelo area to East of Abilene and northwest of the DFW Metroplex.

When we lay surface winds and pressure over the image, you can see the frontal boundary / dryline extending along or just West of the thunderstorm line:

Below is a recent image from the DFW area radar showing its perspective of the thunderstorm line:

The problem at the moment is that the line itself is nearly stationary, while individual storms within the line are moving Northeast at 25-30 mph.  This will not only pose a threat of large hail and strong winds with the stronger storms, but will increasingly result in a flash flooding threat as storms move over the same areas again and again.

High resolution computer forecast models indicate that between 10 and 11pm, conditions will change to the West of the line, such that it should finally begin a push off toward the East.

If this trend continues, the DFW Metroplex could expect to see thunderstorms between 10pm and Midnight.  The I-35 corridor from South of DFW through Waco would expect to see the activity between Midnight and 2am, and the southernmost end of the line, from Georgetown through the Austin / San Antonio corridor would see the activity after 3am CDT.

If the thunderstorms begin to intensify between now and 10pm, they could begin to push themselves off of the wind shift line on their own, which could cause the above arrival times to be earlier than currently expected.  We'll continue to monitor trends and make at least one more updated post on the Texas storms before the evening is over.

A Severe Thunderstorm Watch continues until 2am CDT for much of northcentral through westcentral Texas:


KE5WLM said...

Id take a dose of severe weather just to get a decent rain here in SE NM. We have had less than .50" since Oct 1st of last year.

Rob In Texas said...

I'm with 'ya! I'm holding my breath and crossing my fingers here between San Antonio and Austin, but it's not a sure thing!