Story highlights More than 4 inches fall at Houston Hobby Airport, setting a record

National Weather Service to investigate possible tornado touchdowns

Houston has conducted 20 to 30 high-water rescues, another official says

Severe weather hit the Houston area Monday, flooding streets and homes and leaving thousands of people without power, emergency officials said.

Torrential rain fell across the area, causing flash flooding that left streets and highways impassable and submerged some vehicles.

"We have a lot of roadways closed, and some evacuations are going on," said Alan Spears of the Fort Bend County office of emergency management.

In the city of Richmond, rescues were conducted by boat and on foot. Spears said he believes a tornado touched down in the area.

"We had 7,000 people without power in the county," he said.

Sixty miles southeast, in Texas City, a law enforcement officer witnessed what appeared to be a tornado strike near the Mall of Midland, the National Weather Service reported.

The Houston/Galveston weather forecast office will examine the area and two other reported areas on Tuesday to confirm reported strikes, said Timothy Oram, an emergency response meteorologist for the National Weather Service in Fort Worth.

As much as 6.3 inches of rain had fallen in the past day, nearly all of it during the previous 12 hours, Oram said late Monday afternoon.

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At Houston Hobby Airport, 4.05 inches of rain fell, which douses the previous January 9 record of 2.54 inches set in 1955, according to Oram.

Though flash flood warnings were still in effect for Chambers County and Galveston County, the worst was over, he said. "It's moved off to the northeast; things should be improving here," he told CNN.

Video from Fort Bend County showed wind damage, including debris from building roofs and broken glass, and people trapped by the storm described terrifying moments.

One resident said he felt the wind pushing into his home just before the garage door fell in and the front door of his home was blown open.

"It just kept getting louder and louder and louder," Umair Sayyed told CNN affiliate KPRC.

Sayyed said he and his mother and sister sheltered inside a closet moments before the roof fell and rain poured into his home.

Michael Walter, spokesman for the Houston Office of Emergency Management, said the city conducted 20 to 30 high-water rescues.

The rain was falling so hard and fast in Houston that the weather service recorded 1.6 inches in just 10 minutes. No injuries were reported.