Oct 24 (Reuters) - Heavy rains swamped Texas overnight, forcing the evacuation of some residents in at least one county, stranding drivers on flooded streets in the central part of the state and causing cancellations of dozens of flights at Dallas/Fort Worth International Airport, officials said on Saturday.
A Union Pacific freight train derailed in Navarro County, south of Dallas, as flood waters covered the tracks. The derailment left locomotives and some of its rail cars on their side, according to a company spokesman and TV footage.
The rain was expected to intensify over the weekend as moisture from tropical depression Patricia, which struck the Pacific coast of Mexico on Friday as a very powerful hurricane, meets with a storm system coming from the west and over Texas.
Western and northern regions of the state were drenched in the last 24 hours with between 5 inches (13 cm) and 6 inches (15 cm) of rain, authorities in Texas said in a statement on Saturday morning.
Many parts of the state could see more than 8 inches (20 cm) of rain over the weekend, said the statement from the Texas Division of Emergency Management.
Authorities in Navarro County requested sandbags for some homes that were being evacuated due to flooding, the statement said. It was not immediately clear how many homes were evacuated.
Interstate 45 in Navarro County was shut down in some spots due to rising waters, stranding some drivers, the department said.
About 100 flights were canceled on Saturday at Dallas/Fort Worth International Airport, one of the country's busiest air hubs, according to tracking service FlightAware.com.
Heavy rain also flooded streets in parts of the state capital, Austin, which has a population of about 910,000.
"We knew going into this that the soil was so dry down here that it may not be instant flooding, because it was going to suck up a lot of the moisture," said Austin Fire Department spokesman Matt Bennison.
"But now we're fully saturated and there's more rain on the way," he said.
Flooding on Highway 71 in Austin swept a car into a nearby creek, but the woman inside was able to escape, Bennison said.
One road in Austin was inundated with over 3 feet (0.9 meters) of water. Flooding forced crews to close a number of bridges over water ways that normally have low flows, according to a city of Austin Twitter feed. (Reporting by Alex Dobuzinskis in Los Angeles; Editing by Frank McGurty and Frances Kerry)