Heavy Rain, Possible Flash Flooding This Week

Hurricane season may have passed its statistical peak last week, but the tropics remain a hotbed of activity. And while there are no hurricanes that are threatening the Texas Gulf coast, a tropical disturbance in the Gulf is likely to produce some very heavy rainfall across the region beginning Tuesday.

The disturbance, which is unlikely to become a tropical storm before making landfall — the National Hurricane Center only gives that a 20 percent chance right now — should move on shore around the Texas coastal bend and move very slowly northward through Thursday evening. The National Weather service is forecasting 2 to 4 inches of rain for a large area of southeast Texas, with potentially much higher totals in isolated areas.

The latest runs of some of the better forecasting models are suggesting there could be some areas of 10-12 inches or more between Tuesday and Friday.

Even though this isn’t expected to be a strong tropical system, the atmosphere is loaded with moisture, two to three times more than normal, in fact. The mixture of the tropical moisture can have a potent impact on rainfall amounts. At this point, it is impossible to pinpoint exactly where those higher amounts might fall. Most of the forecasts put the heaviest rains to the south and west of central Houston, but certainly we are all going to get a lot of rain with this system.

We don’t have to tell you that 12 inches of rain, even spread out over 72 hours, is a lot for our area. It’s clearly not anything we can’t handle, but with the potential for even more than that possible, it bears watching closely over the next couple days, particularly if you are in an area prone to flash flooding. This isn’t just a drought busting rainfall. This has the potential to be a serious flooding event.

Street flooding will likely be our biggest concern with this storm. Some downpours could drop 2 to 3 inches of rain per hour while moving fairly slowly. The more you can stay off the roads the next couple days, the better and, of course, don’t drive into water if you don’t know how deep it is.

We will have updates as we continue to watch the system develop.