Today, we reach a crossroads.
The Storm Prediction Center (SPC) has issued a Slight Risk area today for southern Texas, as shown below:
Associated with the Slight Risk is a 5% Tornado Threat Ring:
However, the real question is, “Do we chase this, or do we go after tomorrow’s potential threat in the High Plains?”
Here’s the issue: the tornado threat might be higher today than tomorrow, and we are at the top edge of the threat today. If we chase today and go south, we will not have many options for getting north and chasing tomorrow. However, today’s tornado threat looks a lot more like yesterday’s: messy, rainy, low clouds, little structure. There might be a greater chance of tornadoes, but with the rain, we would have trouble seeing them anyhow. Tomorrow, the chances are lower, but the storms are slightly more likely to become supercells. Then, if they manage to produce a tornado, we are much more likely to see it. Either way, storms tomorrow will be more scenic than the ones that will form today.
A quick glance at the surface observations shows cool temperatures and heavy cloud cover, everywhere. The dryline (blue line) has retreated into New Mexico. If we choose to chase tomorrow’s threat, it will be the key player, and it can move into the Texas Panhandle easily. I’d like the winds to be from the south or southeast, but supposedly that will change by tomorrow afternoon, and we will have a strengthened low-level jet.
The visible satellite imagery shows all of the target areas are under heavy cloud cover. It’s raining here in Austin.
The 12 Z upper air sounding from Corpus Christi, TX, shows a much richer atmosphere, with good, 2306 J/kg of Convective Available Potential Energy (CAPE), -12 J/kg of Convective Inhibition (CINH), and a small capping inversion. The shear is better than yesterday, with 9 kts of low-level shear and only 43 kts of deep-layer shear available.
The HRRR Simulated Reflectivity shows cells popping early, with bunches of storms firing by 20 Z. They turn into a blob quickly.
The HRRR Helicity Swaths plot does not give me a lot of hope of discrete cells today.
Thank you for reading my post. I will update as I can.
We will probably punt on the threat today and head to the Panhandles Region for tomorrow. The chaseability of today’s weather is not high. I’d much rather see a sculpted supercell, even if it doesn’t tornado, then to get to some rain-wrapped mess in Corpus Christi.
Basically, the shear is better, the energy is lower, the boundaries more of a mess, and the chase terrain is worse, as compared to yesterday. I think if we went south, it would be a similar day to yesterday- driving in the rain with 100 yards of visibility.