Heavy Rain, Thunderstorms May Lead to Flooding in Parts of the South Through Early This Week

Brian Donegan
Published: May 21,2017
Persistent areas of rain and thunderstorms will set up over the southern states through early this week, raising concerns for urban and flash flooding.
Torrential rainfall caused flooding in the Montgomery, Alabama, area late Saturday resulting in numerous flooded roadways. A total of 8.15 inches of rain fell in Montgomery on Saturday, making it the wettest May day on record in the city.
Additionally, 10.02 inches of rain were measured near Frio Town, Texas, southwest of San Antonio, in the 24 hours ending 7 a.m. CDT Sunday morning.
Sunday afternoon, water and debris flooded some roadways in Zapata and San Ygnacio, Texas.
(MORE: Summer 2017 Temperature Outlook)

Current Radar, Watches and Warnings

An area of low pressure will develop along a stalled front near the Gulf Coast and slide east over the next few days. That low will pull abundant tropical moisture northward from the Gulf of Mexico, providing the fuel needed for heavy downpours to develop.
For this reason, the National Weather Service has hoisted flash flood watches for parts of southeast Texas, southern Louisiana, southern Mississippi, southern Alabama, the western Florida Panhandle and the southern Appalachians.

(MORE: 4 Things to Know About the Upcoming Late-May Weather Pattern Change)
Here's a general outlook of what to expect in the days ahead.

• Monday: Heavy rain and thunderstorms are expected along the Gulf Coast from south-central and southeast Texas to southern Alabama. Flash flooding will likely occur where thunderstorm clusters stall or move too slowly, and the best chance of this happening is in southeast Louisiana and far southern Mississippi.
• Tuesday: The area of heavy rain and thunderstorms will slide a bit east, as southeast Louisiana through Virginia runs the highest risk for urban and flash flooding. This is the day flooding may be the most widespread, with the most moisture available to feed storms over a larger area.
• Wednesday: Lingering showers and thunderstorms are possible near the Southeast coast from North Carolina to central Florida. Locally heavy downpours remain possible, which could lead to additional areas of flooding. This rainfall, however, will be beneficial for parts of the Florida Peninsula experiencing drought conditions.

South Outlook

Many areas in the South will pick up 1 to 3 inches of rainfall through Wednesday. However, where thunderstorm clusters stall or move too slowly, higher amounts are expected.
The best chance of greater than 3 inches of rain will occur in a swath from south-central Texas eastward through the Gulf Coast region to the Carolinas. A few places may even see more than 5 inches of rainfall, including southeast Louisiana.
(FORECAST: New Orleans | Houston | Mobile)
The good news is that flood-ravaged Oklahoma, Arkansas and Missouri will avoid the majority of the heavy rainfall.
In addition, this rainfall will likely be beneficial in easing drought conditions that remain in place across much of Georgia, Florida and Alabama, as well as northeastern Mississippi and western South Carolina.

Rainfall Forecast Through Wednesday

These high rainfall amounts will cause rivers and streams to rise, and will also slow the recession of the recently flooded Mississippi and White rivers.
(MORE: 2017 Atlantic Hurricane Season Forecast Update)
The Mississippi River at Vicksburg, Mississippi, is not forecast to fall below moderate flood stage until next week.
The Mississippi River at Baton Rouge, Louisiana, is expected to crest at major flood stage late this week.

MORE: Severe Storms, Flooding Hit Plains, Midwest

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