Here's how much rain our Super Microcast model says will fall during the day:

The heaviest rain will fall from the rush hour through afternoon. With that much rain falling, I expect to see flooding of highway feeder roads and low-lying roads. The system producing the rain should move through fast enough that our Bayous and stream should drain fast enough.

The set-up is what I've written about over the past few days: remnants from the former tropical storm Rick as being swept into Texas ahead of a strong cold front moving in from the Rockies. The front acts as a lifting mechanism and it's a case of what goes up must come down and man, will it come down!

Here's a breakdown of the timeline for the arrival of the heavy rain and the front. The day begins with steady rain for the morning commute:

Then it comes down harder around lunchtime:

It should be moving out late in the afternoon as the front pushes through with cooler and drier weather behind the front: