Major Flooding May Ensue in Texas, Oklahoma and Arkansas This Weekend

By Alex Sosnowski, AccuWeather.com Senior Meteorologist

October 21,2015; 10:38PM,EDT

 

 

The potential for major flooding will increase from west to east over abnormally dry and drought-stricken areas of the South Central states into early next week.
Areas of persistent or slow-moving torrential rain will affect Arizona, New Mexico, Colorado, Texas, Oklahoma, Kansas, Arkansas and Louisiana. While the rain will aid some communities by marking an end to the wildfire risk, greening up lawns and grazing lands and replenishing water supplies, it will come at a price.
The risk of flooding and locally severe thunderstorms will continue to affect the deserts, southern Rockies and southern High Plains as a non-tropical storm pushes eastward through the Four Corners into Thursday.

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In portions of Texas, Oklahoma, Arkansas and Louisiana, the situation could turn out similar to flooding this past May in the same areas. It is also possible the situation may become as extreme as the South Carolina flooding from early October. A foot of rain is likely to fall on some communities over the span of three days or less.
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.

Areas that are likely to first experience flash flooding will be arroyos, low water crossings and small streams.
As the rain progresses slowly to the east and into more populated regions where the moisture supply will be greater, the risk of flooding will expand to urban areas and larger rivers on Friday, during the weekend and into early next week.
The risk of flooding could become far-reaching and affect the major cities of Dallas, Houston, Austin, San Antonio, Amarillo and Brownsville, Texas; Oklahoma City and Tulsa, Oklahoma; Dodge City and Wichita, Kansas; Fort Smith and Little Rock, Arkansas; and Shreveport and Lake Charles, Louisiana.
In some communities, the flooding could become severe enough to force evacuations.
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The main cause of the wet weather pattern and the upcoming flood risk will be tropical moisture from multiple sources converging on the South Central states.
The Gulf of Mexico and the 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, adding to the moisture.
Another storm may form near the Texas coast and join the deluge later this weekend into early next week.
According to AccuWeather Hurricane Expert Dan Kottlowski, "Wind shear will continue to be a deterrent for tropical development in the Gulf of Mexico as it has been over much of the Atlantic basin this year."
Wind shear is a rapid change in direction and speed of air flow at different levels of the atmosphere. Wind shear can prevent a tropical system from forming and cause an organized tropical system to weaken.
If the wind shear was to weaken, there could be enough time for the storm system to develop tropical characteristics in the Gulf of Mexico.

Regardless of whether or not tropical development occurs, the risk for significant flooding centered on southern and eastern Texas will remain, Kottlowski said.
Drenching rainfall is likely to shift eastward over the lower Mississippi and Tennessee 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 not only puts 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 beneath the water.
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.