What Could Have Been .... Wasn't

Conditions were literally ripe for a significant severe weather episode along the I-35 corridor from San Antonio to Austin late yesterday evening/early this morning.  Though there were several severe reports (including a swath from San Antonio through Seguin from stronger cells that rolled through after 1am) what could have been a widespread, damaging episode simply wasn't.  As the old saying goes, we "dodged a bullet" last night/this morning - for sure!

The most interesting storms during the entire event occurred within a consistent band from near Eagle Pass to north of Crystal City.  Several of the cells that developed within this area showed rotation on numerous occasions.  I suspect there were tornado touchdowns in these areas, but due to the very rural and "spotterless" nature of the area, nothing was reported.

These same storms exhibited other classic signs of supercellular organization, including a couple of splits and a tendency to move to the right of the prevailing motion in the area (i.e., they originally started moving Northeast then turned into more of a due East motion over time).

Here is a reflectivity screenshot from the Laughlin AFB (Brackettville, TX) radar shortly after 11pm last night.  The cell immediately Northeast of Eagle Pass was in the process of splitting at the time, while the cell North of Crystal City was showing rotation on the Southwest flank.  (Sorry about the text box, that was a shot I used for a Twitter posting).

Meanwhile, numerous clusters of strong thunderstorms moved Northeast across areas West of I-35 to the West and Northwest of the San Antonio-Austin corridor throughout the late evening.  Between 12 and 1am Saturday morning, much of this activity collapsed and a strong gust front blew Southeast into the Austin-San Antonio areas.  At 12:35 a.m. I measured a 57 knot wind gust here at my home near Kyle (just South of Austin on I-35, at mile marker 217).

I attempted to upload reflectivity and velocity images of the above gust front, but I'm having technical problems right now.  I'll try again later and update this post...have to run right now.

Tornado Watch for Austin-San Antonio corridor until 6am Saturday

Thunderstorms are developing rapidly North of the Big Bend into west-central Texas now that intense upper level energy is moving deeper into the area (see last blog post for satellite image).  San Antonio is located at the right-most center part of the image below, taken at 9:59pm from the Laughlin AFB radar:

For the next 2 hours, the greatest threats will be increasingly large hail and gusty straight-line winds.  Toward and after Midnight, as the activity moves toward the I-35 corridor, conditions will become more supportive for possible rotation and tornado development.

Please stay alert as this potentially dangerous situation is made worse by the fact that it will reach the more populated areas well after most folks head off to bed.

Severe Weather For the TX I-35 Corridor This Evening & Tonight

Thunderstorms are beginning to fire in West-Central Texas along the main frontal boundary and immediately ahead of a strong upper level weather disturbance approaching from the West/Southwest:

Initially, large hail and damaging straight-line wind gusts will be the primary threats.  However, as the activity becomes more organized and the upper level forcing and stronger wind shear overspreads the I-35 corridor area later tonight, the threat of tornadoes will increase as well.

Nighttime severe weather situations are particularly dangerous.  Especially given this scenario where a large population area (i.e., the I-35 corridor from San Antonio to Austin) will potentially be affected after Midnight.  It is critical that all residents across the area stay alert tonight and be prepared to seek shelter should severe weather threaten their area.

It's not too late to buy a NOAA Weather Radio, which can alert you to severe storms 24-hours per day.  You can even program many newer models to only sound the alarm when severe weather threatens your immediate area.  Radio Shack, Wal-Mart, Target and other major retailers sell a variety of these devices.

Severe Weather Preview in the TX Panhandle This Evening!

Awesome shot of a tornado on the ground near Bushland, TX earlier this evening:

Snapshot of the Amarillo radar, Storm Relative Velocity mode, showing strong rotation just Southwest of Canyon, TX at about 8:10 pm CDT this evening:

The brighter orange and near yellow color shows wind blowing away from the radar (upper right corner of the shot) at approximately 65 mph.  Brigher green immediately adjacent shows wind blowing toward the radar at approximately 30-35 mph.


This should be just a preview of what's to come later this week....if current model trends verify.  More to come...

Ask and Ye Shall Receive

Yesterday I wrote a post remarking about how the Storm Prediction Center (SPC) had suddenly removed the extended period severe weather outlook areas later this week.  On today's early morning update the risk areas appeared once again.  The forecaster cited greater confidence in model data/consistency, among other things. 

It was a very busy day at work so I'm going to take a minute to gather my thoughts, examine all available data and then I'll post more on my opinion of the greatest threat area(s) later this evening or tomorrow morning.

Awesome Photo

Take a look at the latest spectacular volcanic eruption photo...with CG lightning no less!

Awesome shot by Marco Fulle!  (per UK Telegraph online).

SPC Day 4-8 Outlook

Don't get me wrong - I'm a huge fan of the SPC.  I'm just wondering why they removed the "extended range" severe outlook areas for later this week.  My understanding of the day 4-8 outlook is that it was designed to alert users to potential "large scale" events.  Model data continues to support widespread strong to severe weather later this week, over a large part of the country, so I'm perplexed as to why the risk areas that were up over the weekend have disappeared in the last 24 hours.  I strongly disagree that, as noted in the last discussion, the "predictability is too low" for the day 4-8 period this week.