This is caused by a mountain wave flattening a thin layer of clouds against the lower stratosphere:

It's worth noting that forecast models are all over the place in terms of timing, so the front could arrive earlier than shown in this visualization.

Definitely!

This will be an interesting test run for sure. Looks like the strongly surface-based inflow verified with the tornado north of Houston #txwx

An example of the new "stepwise" CAPE and CIN plot being tested for SounderPy in the bottom right. The left sounding is north of the front, the right sounding is south of the warm front.

Here's the PR! Feel free to suggest changes:
github.com/kylejgillett...

Comparison of this windstorm (left) and the one that occurred during the Marshall Fire (right). The resemblance is uncanny aside from a few notable differences in the temperature profiles.