The US National Weather Service has put a flash flood watch in effect for large parts of Houston, Texas following heavy rainfall which caused floods that left six people dead.
Over 1,000 water rescues have taken place since the flooding began.
Scores of Houston-area schools closed for a second straight day as more rain pelted the fourth most populous US city overnight
As much as 45cm fell in a 24-hour period in some areas of Harris County, which includes Houston, and the weather service said heaviest daily rain records were set on Monday at the city's two main airports.
A low pressure system in Colorado and surrounding states pulled moisture from the Gulf of Mexico, sparking a string of heavy thunderstorms that drenched nine counties for hours early on Monday, according to the National Weather Service.
Such heavy storms that park atop the city for such long stretches can quickly overwhelm Houston's system of drainage channels that move water back to the Gulf via the Houston Ship Channel, particularly if the ground is already saturated.
More than 6,300 customers were without power in the Houston area on Tuesday afternoon, a sharp decrease from more than 100,000 a day earlier, Center Point Energy said.
Flood waters that blocked roads to downtown and other main areas of the city have mostly receded, and officials said most people should be able to make it back to work.
At a news conference, Houston Mayor Sylvester Turner said about 20 inspection teams from city hall were in the field and that 183 houses have been damaged.
The city is moving quickly to remove debris so that it does not pile up and shelters are being set up, he said.
More than 100 flights were canceled on Tuesday at Houston George Bush Intercontinental Airport, according to tracking service FlightAware.com.
Over 1,000 flights were canceled at major Texas airports on Monday due to the storms, it said.
Rains in other parts of Texas were expected to cause rivers to crest later in the week, bringing floods to downstream areas.
