Flood Threat Continues in the Southeast

Jon Erdman
Published: November 18,2015

A widespread swath of heavy rain and thunderstorms will continue the risk of flooding in parts of Georgia and South Carolina into early Thursday.

Flood Watches and Warnings

Tuesday into early Wednesday morning, localized flooding was reported in Mississippi, Arkansas, southern Missouri, northwest Louisiana and eastern Texas, resulting in several road closures in those areas. Flash flooding moved into parts of Georgia by Wednesday afternoon.
The most numerous flood reports were in southern Missouri Tuesday where more than 5 inches of rain has fallen in some locations. A storm total of 6.85 inches was measured in Pershing, Missouri.
Some patchy flash flooding was reported around the Atlanta metropolitan area on Wednesday.
The widespread area of heavy rain is from the same area of low pressure aloft that has brought severe weather to the Plains and South, and a blizzard to the High Plains. Ahead of this low, a plume of deep, tropical moisture is being tapped not just from the Gulf of Mexico, but also from the western Caribbean Sea and eastern Pacific Ocean south of southern Mexico's Coast.
The satellite loop below sent in a tweet by the National Weather Service showed an impressive slug of moisture ahead of the storm system streaming northward from the tropics to the Arctic Circle on Tuesday.

While this intense upper-atmospheric low did not completely stall out, its eastward progression is slow enough that, combined with the impressive moist plume ahead of it, excessive rainfall and localized flooding will likely continue.
For now, the area of greatest concern for flooding rainfall through Thursday morning will be in parts of central to eastern Georgia and much of the Carolinas. Flash flood or flood watches have been issued by the National Weather Service for parts of those states.

Rainfall Potential Through Thursday

Much of this area has a strong potential of seeing up to 3 inches of total rainfall from this system through Thursday.
(FORECAST: 7-Day Rain Maps)
As is typically the case, it is not possible to delineate exactly where slow-moving bands of heavy rain and thunderstorms will stall out. Areas in these stalled rainbands will likely see much higher amounts, possibly up to 5 inches, with rainfall rates of 1 to 2 inches per hour or higher.
Here is the latest general flood threat timing outlook:

• Wednesday night: The heavy rain threat slides east, extending from northern Florida into Georgia and the western Carolinas.
   
• Thursday: Pockets of locally heavy rain are possible along the front in the East, from New England to Florida. However, the flood threat should be lower.

(MAPS: 7-Day National Rain Forecast)
Remember, never drive into flood waters of unknown depth or drive around barricades. Your vehicle may be the biggest danger in a flash flood. Turn around, don't drown.
The radar map(s) below focus on the most likely areas for severe weather and/or flash flooding, if any. Maps update every five minutes; refresh this page for the latest image.

Current Radar with Watches and Warnings

Current Radar with Watches and Warnings

Statewide precipitation rankings in October 2015, relative to past Octobers since 1895. (NOAA/NCEI)
(NOAA/NCEI)

Pouring It On

We mentioned earlier the twin flash flood events in late October in parts of Texas and Louisiana.
(RECAPS: Late October "Patricia-Remnant" Deluge | Texas/Louisiana Flooding Ends October)
The Lone Star State had its fifth wettest October on record. Waco, Texas, and Baton Rouge, Louisiana had their record wettest October.
Here are some rather staggering one-month rainfall totals in parts of Texas and the Lower Mississippi Valley ending November 12:

• Baton Rouge, Louisiana: 17.55 inches
• Waco, Texas: 17.06 inches
• New Orleans: 13.83 inches
• Houston: 13.71 inches
• Jackson, Mississippi: 12.46 inches
• Shreveport, Louisiana: 11.08 inches

In general, these rain totals are all at least 6 inches wetter than average for that period. Waco's total is almost 13.5 inches wetter than the norm for Oct. 12 through Nov. 12.
Despite a burgeoning late summer/early fall drought, January through October was among the top 10 wettest such periods in both Oklahoma and Texas, largely due to the epic rainfall in May, June and the twin October events.
January through October was the third wettest such period in the Lone Star State dating to 1895, and the wettest since 1941.
Dallas-Ft. Worth, Austin (Bergstrom Airport) and Corpus Christi, Texas, have each had their record wettest year-to-date through November 12, according to the Southeast Regional Climate Center.
Numerous other locations in the southern Plains, Lower Mississippi Valley and western Gulf Coast have also had one of their top 10 wettest years-to-date, including:

• Fort Smith, Arkansas: 4th wettest
• Houston: 6th wettest
• Baton Rouge, Louisiana: 7th wettest
• St. Louis: 7th wettest

Check back with us at weather.com for the latest on this potential flood event.
Jonathan Erdman is a meteorologist at weather.com and has been an incurable weather geek since a tornado narrowly missed his childhood home in Wisconsin at age 7. Follow him on Twitter and Google Plus. 

MORE: Texas Flooding Oct. 21-25, 2015