The lack of soundings in the area has always haunted me when I chase in Central Or South Texas (Upper-left graphic). Yesterday is a prime example of how, if you read between the lines, the capping that showed up on 18z Corpus Christi sounding was evident in Northern Mexico a few hours prior. 

This, along with thick low clouds limiting mixing, did yesterday in before it even had a chance. There were exactly 0 preliminary storm reports yesterday despite the day beginning as an enhanced risk. It is always important to look at why setups don’t take off after the fact, as it is important to look at setups that do.

In the bottom-left graphic, you can see the substantial capping layer present in NE Mexico on the 12z sounding. If you checked on mesoanalysis, this was also present inland across Texas. But Corpus Christi’s 12z sounding near the coast had little to no capping in the morning. (Bottom Center)

By 18z (or noon local time), the Corpus Sounding had significant warming just above the 850mb layer. There was an erroneous dewpoint on the 18z sounding, with much lower actual moisture. This resulted in a substantial amount of CINH on a mixed layer sounding. When you combine this capping with the extremely thick cloud cover and cool surface layer further NE in the risk area, it’s not hard to see how storms failed to materialize until evening nearer the coast in Louisiana.

Days like this are always difficult to forecast because some of the factors can be tricky and surprising — if the skies had cleared in SE Texas yesterday, the odds of enough heating occurring to allow for more robust updrafts would’ve been much higher. The key lesson is, and always will be, to pay attention to observed weather data before you check in with models.