HOUSTON – Update 10:30 a.m.
Houston Mayor Sylvester Turner says at least one person has died from torrential flooding. Officials say there have been 2,500 calls since midnight for water rescues.
Update 10 a.m.
Staff at a Houston television station broadcasting live coverage of Tropical Storm Harvey had to evacuate after water from nearby flood-prone Buffalo Bayou started to gush into the building.
KHOU-TV tweeted images Sunday of water pushing through a front door and flooding the lobby. Other images showed sand bags placed against another door had failed to stop the water that was already ankle deep.
Update 9 a.m.
President Donald Trump says he will be traveling to Texas "as soon as that trip can be made without causing disruption" in the wake of Hurricane Harvey.
Trump tweeted that the "focus must be life and safety."
Update 8 a.m.
Flooding in some parts of the county that includes the city of Houston is so bad that residents are being urged to seek refuge on their roofs.
Harris County Flood Control District official Jeff Lindner says people inundated by rising waters shouldn't crawl into attics of their homes but should get on top of them.
He says rainfall of more than 4 inches per hour has sent water higher than in recent Houston floods side and are exceeding levels seen in Tropical Storm Allison in June 2001.
Update 6:40 a.m.
Authorities say rescue attempts continue in Houston for those stranded inside flooded homes and submerged vehicles in the wake of Harvey.
The Houston Chronicle reports that hundreds of calls have been fielded for water rescues as of early Sunday, including Houston police officials who evacuated two apartment complexes and rescued more than 50 children.
Meanwhile, Harris County Sheriff Ed Gonzalez and Houston Mayor Sylvester Turner on Sunday continued urging residents via Twitter to "shelter in place" and stay off rain-swollen roadways.
Gonzalez actively used Twitter overnight to field assistance for those trapped inside water-soaked homes, attics and vehicles. Those appealing for assistance or being steered to help via Gonzalez's Twitter feed included a person suffering "cardiac-arrest," and a woman who posted: "I have 2 children with me and tge,water is swallowing us up. Please send help."
Gonzalez at one point appealed for calm and patience, saying officials were "trying to make it to everyone as best we can."
Turner's official Twitter account said "911 services at capacity. If u can shelter in place do so, a few inches in your home is not imminent danger. Only call if in imminent danger."
Update 6 a.m.
The National Hurricane Center says Harvey continues to cause "catastrophic flooding in southeastern Texas."
The Houston area has been hit with major flooding and several residents have been seen walking in waist high water in neighborhoods and across flooded highways.
The hurricane center says in its 4 a.m. Sunday update that the tropical storm has maximum sustained winds of 45 mph (72.42 kph) and remains stationary about 45 miles (72.42 kilometers) northwest of Victoria, Texas.
A storm surge warning and a tropical storm warning also are both in effect for Port O'Connor to Sargent. The hurricane center says a storm surge warning means there is a danger of life-threatening inundation from rising water moving inland from the coastline.
The center says Harvey is likely to weaken to a tropical depression later Sunday. Harvey made landfall Friday night as a Category 4 hurricane.
Meanwhile, the National Weather Service says a Flash Flood Emergency over west and central Harris County, where Houston is located, as well as for eastern Fort Bend and northern Brazoria counties remains in effect until 6:15 a.m. Sunday, calling it a "Particularly Dangerous Situation."
Check out the latest satellite image and find out where Harvey is headed.
Continued Weather Coverage
Stick with KSAT 12 News, your Weather Authority for the latest weather updates.
Remember, 'Turn Around, Don't Drown': Tips for staying safe while driving in the rain
Read more: CPS Energy offers power outage tips
Download the KSAT 12 Weather app on your smartphone for the latest weather updates.