Dangerous Flash Flooding, Along With Severe Thunderstorms, Tornadoes in the South (FORECAST)

Quincy Vagell
Published: March 9,2016



 
As feared, torrential rain has triggered major flash flooding across parts of the South, and more heavy rain is yet to fall over the next day or so over the same areas that have been swamped already.
Hardest hit so far has been parts of northern Louisiana and northeast Texas. Over 14 inches of rain has fallen just to the southeast of Shreveport, Louisiana, near Bossier City since early Tuesday, where a flash flood emergency was issued by the National Weather Service due to the number of roads flooded, water rescues and homes flooded.
(MORE: Latest Damage Reports | Interactive Storm Reports Map)
Flooding prompted evacuations in Greenwood, Haughton, Homer, Minden and Rayville, Louisiana. Multiple bridges have been washed out northeast of Marlin, Texas.

Radar, Watches and Warnings

Unfortunately, the heavy rain will continue over this hard-hit part of the South for another 24-48 hours before slowly shifting east.
This will only worsen ongoing flash flooding and lead to moderate to major river flooding in a few areas once water drains from smaller tributaries to mainstem rivers in the coming days.
(MORE: Your Vehicle Can Be Biggest Danger In Flash Flooding)
Among the cities that should be alert for additional major flash flooding the next few days are Houston, San Antonio, Austin, Shreveport and Little Rock, Memphis and New Orleans.
If that wasn't enough, severe thunderstorms and at least some tornadoes, are expected through Thursday in some of the same parts of the Lower Mississippi Valley and Gulf Coast.
Below is a breakdown of the flooding and severe weather threats the next several days followed by an explanation of what is causing the stormy weather.
Flooding Threat

• Flash flood watches continue from east Texas, Louisiana and southern Mississippi to eastern Missouri and southern Illinois.
• Through Thursday morning: Periods of heavy rain continue in east, central Texas, Arkansas, southeast Oklahoma and western/northern Louisiana. Some pockets of locally heavy rain are also possible into the mid-Mississippi and Lower Ohio Valleys.
• Later Thursday into Friday: We can't rule out pockets of lingering heavy rain in Deep South or east Texas and western Louisiana, the bands of heavy rain should migrate slowly east into the Lower Mississippi Valley (southeast Louisiana, Mississippi, perhaps Alabama). Some heavy rain may persist in the Ohio and mid-Mississippi Valley through Thursday night before a cold front drags through.
• Saturday: Bands of locally heavy rain may still persist near the northern Gulf Coast from Mississippi to Alabama and the Florida panhandle.
• Potential cities: Houston | Shreveport | Little Rock | Jackson | New Orleans | Mobile
• MAPS: 7-Day Weekly Planner 

Rainfall Forecast Through March 12

Flood Alerts

Severe Weather Forecast

Wednesday Daytime-Evening

• Scattered strong to severe thunderstorms are likely over coastal and east Texas, Louisiana and possibly southern Arkansas.
• Damaging straight-line winds and tornadoes are still possible, both within bands of heavy rain and any discrete supercells. 

Wednesday's Thunderstorm Forecast

Thursday

• The severe threat is somewhat unclear and may be less widespread than recent days.
• Nonetheless, a few scattered strong to severe thunderstorms could affect parts of east Texas, Louisiana, Mississippi and southern Arkansas.

Thursday's Thunderstorm Forecast

Locally heavy rain and flooding may linger into Saturday, but the severe weather threat appears to continue to decline to finish the week.

Slow-Moving Low Pressure = Flooding and Severe Weather

A massive, slow-moving, southward dip in the jet stream will inch east across Mexico, then near the Gulf Coast, funneling deep, tropical moisture into parts of the South and Mississippi Valley, a rather unusual pattern for early March.
In fact, atmospheric moisture values (known to meteorologists as "precipitable water") may near or top March records from the northern Gulf Coast into the Great Lakes, values last seen this time of year during the record-shattering March 2012 heat wave.

These ingredients will come together for several bouts of thunderstorms and excessive rainfall from the Plains into the Mississippi Valley and surrounding areas over the next several days.
(MORE: More Flooding in a Warming World)

It appears that the upper level low will begin to finally pull away from the southern Plains this weekend, gradually lessening the threat for severe thunderstorms and flooding.

Storm Reports/Recap

Estimated Rainfall and Flood Reports

Flooding began Monday night west of Ft. Worth, Texas, as floodwaters swamped homes and forced water rescues. Evacuations were ordered in Haughton, Louisiana Saturday evening, when more than 30 homes were flooded. In Minden, Louisiana, water was coming into the Webster Parish Courthouse and at least 40 other buildings were flooded. Water was also reported in homes in Dixie Inn, Louisiana Tuesday evening.
An EF1 tornado caused damage near Cool, Texas Monday evening and an EF1 tornado touched down near Tolar, Texas, southwest of Ft. Worth Tuesday morning. An EF1 tornado also left a narrow path of damage in Stephenville, Texas early Tuesday. A squall line then surged through Ft. Worth packing a 66 mph gust at the Ft. Worth Meacham Airport and a gust to 72 mph at Interstate 820 and Blue Mound Road.
Baseball size hail pounded Voca, Texas Tuesday evening, while jail to the size of golf balls covered the ground in both Evant and Jonesboro, in Texas.
You can find out more on impacts from this storm system at the link below.
(MORE: Severe Weather and Flooding Hit the South)

Continue to check back with weather.com for updated information and forecasts in the coming days.

MORE: Southern Flooding and Severe Weather