Heavy rain will shift from the southern Plains to areas from central and southeastern Texas to Louisiana at midweek.
Rainfall amounts of 2 to 4 inches are possible for Austin, San Antonio and Houston in Texas, while 1 to 2 inches could fall along the I-10 corridor from Beaumont, Texas, to Lafayette, Louisiana.
Parts of central Texas are currently in a moderate to extreme drought, so the rain is certainly welcome. However, rain could come down at rates greater than 1 inch an hour.
Downpours do not soak into the ground as well as a light, gentle rain. The heavy rain will tend to run off into streams and collect or pool in low lying and poor drainage areas.
This can lead to flooding across the threat area and create hazardous driving conditions and travel delays, including on interstates 35, 10 and 45.
Cloud-to-ground lightning will accompany the rain at times. This threat, along with reduced visibility in heavy rain, can create flight delays at the airports.
The heavy rain will move into Austin and San Antonio on Tuesday night and continue into the day on Wednesday. This timing could create headaches for commuters during the Wednesday morning rush.
Conditions will improve for the commute home on Wednesday evening in Austin, but there can still be some downpours around San Antonio.
The steadiest and heaviest rain will arrive in Houston for the evening commute home on Wednesday, with travel delays possible for the Thursday morning commute.
Moisture is being fed into this system from both the Gulf of Mexico and from Vance , which is moving northeast toward the western coast of Mexico.
Drier weather is expected late in the week and into the weekend with cool nights and mild days. The cool nights and wet ground will likely lead to fog development late at night and in the early morning hours.