Another Flood Threat May Be Ahead for Parts of the South

Linda Lam
Published: October 28,2015

Another flood threat may be brewing for parts of Texas and the South late this week, courtesy of a new storm system. The potential for flooding is higher due to last week's extreme rainfall in many of these same areas.
(RECAP: Patricia's Remnants Flooded Parts of Texas, Louisiana)
A southward dip in the jet stream, or trough, will move from the Southwest into the southern Plains late this week into the weekend.
As this storm system moves east, heavy rain is expected to spread from the southern Plains into the lower Mississippi Valley and portions of the Deep South.

Heavy Rain Threat Setup Late This Week

 

 

 

 

 

 

 

Heavy Rain and Thunderstorm Setup

The next southward dip in the jet stream digs into the Southwest late this week and moves through Texas this weekend. An area of low pressure will develop over the Southwest on Thursday and will then move across Texas and eventually the Lower Mississippi Valley.
There are indications that the storm system will be more progressive and will not move as slowly as once thought.
However, even if this system moves along relatively quickly flash flooding will remain a threat, mainly due to the amount of rainfall that fell late last week and into this past weekend, which has left the ground saturated. Consequently, there is less room for the water to be stored and it will not take as much rainfall to result in flooding.
One of the areas that was hit hardest with the last deluge was Corsicana, Texas, which saw more than 20 inches of rain late last week into the weekend. With the recent rains, Dallas-Fort Worth International Airport has now seen 46.67 inches of rain in 2015, making it the seventh wettest year on record there.
The heavy rainfall was not limited to just Texas. New Orleans received nearly 9 inches of rain Sunday into Monday, putting an end to what had been a dry October. Farther east, Mobile, Alabama, measured 5.1 inches of rainfall Sunday into Monday, and Pensacola, Florida, reported 6.74 inches of rain.
There will be plenty of moisture with this next system, but at this time it looks like there will be a smaller timeframe for the rain to accumulate than the previous system.
Widespread rainfall totals of 1 to 3 inches are expected across the southern Plains and into the Lower Mississippi Valley, with pockets of locally higher amounts are possible.

Rainfall Forecast

In addition to the threat of heavy rain, moderate instability in the atmosphere and high dew point values will also lead to the potential for the development of a few severe thunderstorms in portions of Texas Friday. That threat will shift to the east on Saturday.

Timing of the Rain

This system will start to become organized in the Southwest Thursday into Friday. Scattered showers and storms are expected across much of the Southwest, while snow will fall across the higher elevations of Utah, Colorado, New Mexico and Arizona.
Then the rain will begin to move into Texas Thursday night and will continue pushing eastward into parts of the southern Plains, Lower Mississippi Valley and Deep South into this weekend.
Thursday night: Rain and thunderstorms will spread across eastern New Mexico into the western half of Texas, with eastern sections remaining mainly dry. The heaviest rainfall is expected in from western and central Texas into early Friday morning, mainly west of Interstate 35.

Thursday Night's Forecast

Friday: Rain will soak much of Texas and Oklahoma through the afternoon, spreading into Arkansas and Louisiana overnight. The heaviest rainfall will likely be from central Texas into central Oklahoma.
There is also the risk of an isolated severe thunderstorm from southern Oklahoma into central Texas.

Friday's Forecast

Saturday: The rain will persist from far eastern Texas and eastern Oklahoma into Arkansas and Louisiana. Rain will also spread farther east into Mississippi, much of Tennessee and western Alabama. During Halloween night, the chance for rain will reach into the Florida Panhandle, western Georgia and middle to eastern Tennessee. The heaviest rainfall is expected in eastern Texas, Louisiana, Arkansas and Mississippi.
Scattered severe thunderstorms may develop from eastern Texas into Louisiana and southern Mississippi.

Saturday's Forecast

Sunday: Showers and thunderstorms may continue from the Louisiana Gulf Coast eastward into Alabama, Georgia and the Carolinas. Locally heavy rainfall is possible from Alabama into Georgia and South Carolina.
A limited threat for severe thunderstorms may develop along and near the central to eastern Gulf Coast.
The chance for heavy rain decreases to start next week, but showers could continue across parts of the Southeast.
MORE: October 2015 Flooding in the South (PHOTOS)