As the upper low moves closer to the TX/Mexico border overnight, an additional round of heavy rain will be likely across parts of south central and south Texas overnight and into early Thursday.  Evidence of additional lift from the upper low has been evident this afternoon with an increase in scattered strong to severe storm activity across west and southwest Texas.  Storms are anticipated to increase in coverage and move across the state line with impacts across the southern Edwards Plateau and South Texas Plains region by late tonight.  This includes areas from San Antonio west towards the Rio Grande, and southeast towards Corpus, the Coastal Bend region and down into deep south Texas.  Very heavy rain with the potential for rainfall rates up to 2-3 inches per hour is likely.  As soils across the region are already saturated, runoff will cause issues with flash flooding through the early morning hours.  Flash Flood Watches remain in effect for all of south Texas through Thursday night.

Elsewhere across the state, scattered showers are expected to continue off and on overnight.  Any of these storms which develop will be slow movers with the tendency to drop copious amounts of rain wherever they develop.  Small hail is possible with some of the heaviest storms, and downburst winds may also pose a threat as the individual storms collapse and then redevelop along their outflow boundaries.  Pinpointing exactly where will be difficult, but based on current trends, we expect to see continued development across the Permian Basin/Trans Pecos region, northwest Texas and some isolated activity across north central and central Texas.  And of course, we have the threat for more rain Thursday through Saturday as the upper level low enters central Texas by some time on Friday.

For the latest on river flooding conditions across the state, please visit the following link:  https://nwschat.weather.gov/river.php?state=TX