Dallas, Houston and Austin Brace for Life-Threatening Flooding

By Alex Sosnowski, AccuWeather.com Senior Meteorologist

October 22,2015; 10:06PM,EDT

 

 

A slow-moving band of torrential rain will quickly erase dry and drought conditions and will threaten lives and property by way of major flooding in some communities in the South Central states.
People in the South Central states should monitor the weather situation for flooding through this weekend and into early next week, regardless of how dry the landscape may be right now. The hard, dry ground will cause a significant amount of the rain to run off.

Flash Flooding Sweeps Into Texas

Flooding was highly localized in portions of Arizona, New Mexico and Colorado through Thursday. As the rain diminishes in these states through Friday, it will ramp up moving into more humid areas farther to the east, which will also be at the receiving end of a fire hose of tropical moisture.

Rainfall on the order of 4-8 inches will crawl eastward through portions of Texas, Oklahoma, Kansas, Arkansas and Louisiana. There is the potential for some communities to be hit with a foot of rain through Sunday. Much of the rain may fall in a single day or perhaps in a matter of hours.
The storm system produced numerous incidents of flash flooding in western Texas Thursday morning.
The flooding will become far-reaching and affect the major cities of Dallas, Houston, Austin, San Antonio and Brownsville, Texas; Oklahoma City and Tulsa, Oklahoma; Wichita, Kansas; Fort Smith, Arkansas; and Shreveport and Lake Charles, Louisiana.
In portions of Texas, Oklahoma, Arkansas and Louisiana, the situation could turn out similar to flooding this past May in the same areas. However, it is less possible the situation may become as extreme as the South Carolina flooding from early October.
Areas that are likely to first experience flash flooding will be low water crossings, small streams and mainly secondary roads.

As the rain progresses slowly to the east where the moisture supply will be greater, the risk of flooding will expand to urban areas, major highways and larger rivers on Friday, during the weekend and into early next week.
In some communities, the flooding could become severe enough to force evacuations.
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The main cause of the heavy rain and the flood risk will be tropical moisture from multiple sources converging on the South Central states.
The Gulf of Mexico and eastern Pacific Ocean will take turns at pumping tropical downpours northward into the region. During the weekend, both the Gulf of Mexico and the Pacific Ocean may send in downpours at the same time.
Patricia will approach as a tropical rainstorm this weekend. Patricia reached Category 5 hurricane status off the southwest coast of Mexico on Thursday evening local time.
Another storm may form near the Texas coast and join the deluge later this weekend into early next week.
There is a chance that is could develop tropically, according to AccuWeather Hurricane Expert Dan Kottlowski. Regardless of tropical development or not, it's going to prolong the rainfall along the Texas coast and into Louisiana.
"We saw what happened in the spring time and it could certainly be a repeat performance," Kottlowski said.

Drenching rainfall is likely to shift eastward and northward over the lower Mississippi, Tennessee and Ohio valleys during the middle part of next week.
At the very least, travel disruptions are likely due to poor visibility and heavy rainfall. Lengthy airline delays are possible. Some roads may close. Motorists will need to reduce their speed to lower the risk of hydroplaning.
Never attempt to drive through a flooded roadway. Doing so puts not only you and your occupants at risk for drowning, but also your would-be rescuers.
The current could be strong enough to sweep your vehicle downstream into deeper water as 1-2 feet of water is enough to cause most vehicles to lose control. The water level may rapidly rise across roadways, which may be compromised below the surface.
Parents are urged to keep their kids away from stream banks and culverts. The bank of a stream can give way, and rapidly rising water can sweep away onlookers.