The hardest hit will be a broad swath of the Deep South and Southern Plains, where a general rainfall of 2 to 4 inches could lead to localized flooding. Some of the heaviest could fall in greater metro Houston, where flood watches are in effect through Saturday.
The storm isn’t terribly intense, as strong winds and tornadoes won’t be a problem, but it arguably comes during the worst possible time of year as people head home after the Thanksgiving holiday. During this post-Thanksgiving travel spike, 55 million Americans are expected to travel 50 miles or more. Millions more will take to the skies or the rails. Whenever travel is involved, the weather becomes crucial.
The storm is intensifying over the Texas Trans-Pecos and northern Chihuahua, Mexico, where a pronounced counterclockwise vortex can be seen in satellite water vapor imagery. Ahead of the system, relatively mild, wetter air is swirling northward, with colder Canadian air crashing southward in its wake.
Where moisture and cold air overlap, topsoil falls. This is the case in southeastern New Mexico, western Texas Hill Country, and Texas’ Big Bend. Winter storm warnings are in effect for Marfa, TX, and Carlsbad, NM, with a winter weather advisory for Lubbock. The Interstate 10 corridor could be heavily impacted.
Further east, rain was falling on the warm side of the system between Abilene and the Dallas-Fort Worth Metroplex. Additional showers and a few thunderstorms lurked off Houston.
Drizzle and a few showers this morning. Precipitation will increase in coverage this afternoon, becoming more widespread in the late afternoon/evening.
✔️Heavy local rainfall likely
✔️Some strong storms possible
✔️#FloodWatch indeed
✔️ Dangerous offshore winds and seas likely#HOUwx #GLSwx #BCSwx pic.twitter.com/uLAgi1hMdj— NWS Houston (@NWSHouston) November 25, 2022
As the system intensifies, it will pull a tongue of moisture north from the Gulf of Mexico. This would lead to a treadmill of showers repeatedly targeting Houston. The National Weather Service’s Weather Prediction Center has established a moderate level 3 out of 4 risk of excessive precipitation and flash flooding around the city.
The local National Weather Service office warns that “rainfall rates of up to 2 inches per hour are expected with higher rates of up to 4 inches per hour in stronger, slower storms.” This could quickly lead to severe accumulations that would exceed the soil’s ability to absorb runoff, especially in urban landscapes and more densely populated areas.
Further north and west, Austin, Dallas and Longview could see an inch or more, with some slight delays likely along Interstates 10, 20, 30 and 35.
In the Houston-Galveston corridor, also a major hub for air travel, the heaviest rains will fall Friday evening in the first half of Saturday. Anywhere from 2 to 5 inches or more is possible, with the highest totals coming from showers that repeatedly train or move over the same areas.
A marginal Level 1 in 5 risk of severe weather also covers parts of the southern Texas coast, including the Matagorda Peninsula, where a brief passing tornado cannot be ruled out.
Heavy rains in the South and Midwest
By Saturday morning, the strengthening low will move toward central Texas, spreading the main axis of moderate to locally heavy rain across Oklahoma, Arkansas, Louisiana and eastern Texas. A window of six to 10 hours of moderate rain will move through Mississippi, Alabama and Tennessee in the second half of Saturday through overnight or early Sunday, while a lighter region of “enveloping” rain ” will turn back west around the center of low pressure.
General rain of 1 to 2 inches is likely across most of the south, with a half to one inch in Tennessee. Parts of the Midwest could see decent rainfall as well, with just over an inch across most of central and southern Illinois, Indiana and Missouri. Quantities decrease east of the Appalachians.
Sunday rain along the east coast
The Interstate 95 corridor in the Carolinas and Mid-Atlantic will see its rain, about a half-inch to three-quarters inch, arrive centered around noon Sunday, plus or minus a few hours. It won’t be a washout, but moderate to heavy showers can be expected. Lighter rain could trickle up to Chicago for the first half of Sunday; from Sunday evening to Monday, the system will have retreated in New England.
This could result in slow travel between cities such as Charlotte, Raleigh, Washington, DC and New York. Boston, Providence and Hartford will be hardest hit after dark.
