Good Saturday Morning! We have widespread rain ongoing across the eastern half of North Texas, Northeast Texas, and the Hill Country. Activity as a whole is generally confined in a southwest to northeast oriented band. Over the past few hours we’ve seen a decrease in lightning activity with an increase in rainfall rates. The lightning decrease is noteworthy because it means the atmosphere is becoming more tropical as moisture from Patricia streams into Texas. Lightning activity will continue to decrease but rainfall rates will continue increase. Essentially we’ve transitioned from an unstable/stormy airmass into a tropical downpour air mass.
As we continue through the overnight hours towards sunrise here is what I’m anticipating based on the HRRR (High Resolution Rapid Refresh). Rain coverage will increase towards sunrise and its entirely reasonable to expect numerous to widespread moderate rain across North Texas, Northeast Texas, East Texas, Southeast Texas, South-Central Texas, Deep South Texas, and some of the Rio Grande Valley by the mid-morning hours. Rain rates will be enhanced by tropical moisture. We’ll have to watchful of enhanced areas of very heavy rain and training of heavier convection.
Where we’ve seen 2-3+ inches of rain fall since Thursday soils have become saturated. Additional rain will runoff and result in a continued increase in the flash flooding threat. I anticipate we’re going to see an enhanced flash flood threat develop somewhere over the next few hours in the Hill Country extending into parts of North and Central Texas. Exactly who ends up with prolific rainfall rates will depend on where the heavy rain axis sets up shop. Again thats something we can’t really forecast and just have to watch for in real-time. That’s why flash flooding can be so dangerous – especially at night.
After sunrise the threat for heavy rain will increase across Central Texas, South-Central Texas, the Brazos Valley, and Southeast Texas. This is partly due to Patricia and moisture streaming in from Mexico along with increasing lift in the atmosphere. Again we’re going to have to watch for enhanced bands of rain and the issue of flash flooding. With ridiculous amounts of moisture in place the heaviest storms will be capable of producing rainfall rates of 2 to 4 inches per hour. Many outdoor activities across North Texas, Central Texas, and Southeast Texas will have a lightning and heavy rain risk today.