The National Weather Service (NWS) in New Orleans warned of "life-threatening" flash flooding in the area Saturday night through Sunday morning as heavy rain pounded southeast Louisiana, Texas and Mississippi. In southeast Louisiana, more than 9,000 Entergy customers were without power Sunday morning, according to the company's outage map.

⚠️RT: Life threatening flash flooding likely tonight through Sunday morning. a HIGH RISK (the highest threat level) for excessive rainfall exists along the I-12 corridor (BR metro, hammond, Covington, etc) It is rare that a High Risk for heavy rain is issued. ⚠️PLEASE RETWEET⚠️ pic.twitter.com/fEJqi0UiLK — NWS New Orleans (@NWSNewOrleans) May 11, 2019

The NWS said Saturday night that rain was falling at a rate of 1-2 inches per hour.

Current rainfall rates are generally in the 1-2 in./hr range. Good news is that these areas being impacted at this moment 11:03pm haven’t had much rain so far this event. pic.twitter.com/pe5DOTuhfF — NWS New Orleans (@NWSNewOrleans) May 12, 2019

The NWS' Slidell office says the flash flood warning will continue through 8:30 a.m. Sunday as strong storms with heavy rain and frequent lightning move through the area.

There were flash flood warnings earlier Saturday for parts of Texas, including Houston and Austin, as the storm moved northeast.

A train derailed north of Poplarville, Mississippi, due to high water, CBS affiliate WJTV reported. There were no injuries, but officials warned they had to rescue several drivers from high water around the Pearl River. Tornado warnings are also in effect for parts of Mississippi.

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The National Weather Service said the Houston area saw about 1 to 3 inches of rain late Thursday and early Friday, with some places getting 3 to 6 inches. Those storms pelted the Houston area with golf-ball sized hail and flooded streets, leading to several high-water rescues.

Workers open bays of the Bonnet Carre Spillway in Norco, Louisiana, on May 10, 2019. Gerald Herbert / AP

Major flooding was forecast Saturday for the Trinity River northeast of Houston, and other waterways like the Neches River in East Texas also were overflowing.

Steady rain has lashed the broader Texas Gulf Coast region, the San Antonio area and much of North Texas, including Dallas and Fort Worth.