Update, 5:13 p.m.
With the worst of Friday's rains over, Galveston County will be under a flash flood watch for the rest of the evening on Friday, according to the National Weather Service in League City.
Bands of rain and isolated thunderstorms will redevelop near the coast on Friday evening, the weather service said. There could be high rainfall rates in some areas as heavier cells move through the area.
Heavy rain and runoff from saturated ground could cause more street flooding, the weather service said.
Update, 1:04 p.m.
Texas Gov. Greg Abbott has issued a state disaster declaration for counties from the Texas coast all the way to Austin, his office said in a press release.
The declaration was made in advance of a tropical system in the Gulf of Mexico reaching the southern Texas coast this weekend. It was not made specifically because of the rain in Galveston this morning.
“The tropical disturbance impacting the Texas coast poses a threat of imminent disaster, including severe flooding, property damage and potential loss of life,” Abbott said. “While we stand ready to deploy state resources to assist local officials in their response efforts, it is critical that all Texans in the storm’s path are prepared to ensure their own safety.”
The counties included in the declaration are: Aransas, Atascosa, Austin, Bandera, Bastrop, Bee, Bexar, Blanco, Brazoria, Brazos, Brooks, Burleson, Burnet, Caldwell, Calhoun, Cameron, Chambers, Colorado, Comal, DeWitt, Dimmit, Duval, Edwards, Fayette, Fort Bend, Frio, Galveston, Gillespie, Goliad, Gonzales, Grimes, Guadalupe, Harris, Hays, Hidalgo, Jackson, Jim Hogg, Jim Wells, Karnes, Kendall, Kenedy, Kerr, Kinney, Kleberg, La Salle, Lavaca, Lee, Liberty, Live Oak, Llano, Madison, Matagorda, Maverick, McMullen, Medina, Montgomery, Nueces, Polk, Real, Refugio, San Jacinto, San Patricio, Starr, Travis, Trinity, Uvalde, Val Verde, Victoria, Walker, Waller, Washington, Webb, Wharton, Willacy, Williamson, Wilson, Zapata and Zavala.
Update, 12: 30 p.m.
Rainfall rates on Galveston Island have diminished, but the National Weather Service in League City has extended a flood warning for southern Galveston County until 2:30 p.m.
Drivers are still being urged not to drive on flooded roadways.
The Galveston Fire Department has helped remove a small number of people from stranded vehicles, Galveston Fire Chief Mike Wisko said. There have been no reported injuries.
Low tide in Galveston is at 1:36 p.m., which should lead to flooded street draining quickly. The Strand and downtown appear mostly clear of high water at 12:30 p.m.
Update, 11:36 a.m.
There are a handful of impassable streets in Galveston as of 11 a.m., according to the city. Ferry Road, Broadway at 44th Street, Harborside at 14th Street and 51st Street are all impassable, according to the city.
Update, 11:14 a.m.
Flooding in Dickinson isn't currently an issue, head of emergency management David Popoff said, but high water centered around the Nicholstone neighborhood west of the city, as well as in areas surrounding Dickinson High School and Hughes Road Elementary School has been reported, city officials said.
Bryan Milward, Dickinson's director of public works, said the city is getting help identifying trouble spots from a couple drones. Once flooding is spotted, city employees can go out and unclog backed up ditches and tributaries prone to flooding.
Update, 10:31 a.m.
The National Weather Service in League City has extended its flash flood warning for Galveston until 12:30 p.m.
Up to three inches of rain has fallen on Galveston in the last three hours, according to the weather service.
Inland parts of the county are under a flash flood watch until 4 p.m.
Update, 9:53 a.m.
Friday's flooding is not directly related to the tropical disturbance that has been hanging over the Gulf of Mexico in recent days, the National Weather Service in League City said.
That disturbance, which was first detected near the Yucatan Peninsula, now has just a 20 percent chance of turning into a tropical depression or storm.
The heavy rain should gradually move westward, according to the weather service. There will be less rain on Friday night and Saturday, with some scattered thunderstorms possible.
Update, 9:49 a.m.
Texas A&M University at Galveston has canceled classes for the rest of the day on Friday. The school has directed students to shelter in place on campus until further notice.
Update, 9:43 a.m.
The city has placed some barricades across part of the Strand downtown. After a similar storm on Labor Day, some business groups asked the city to do more to prevent traffic from moving around downtown while streets are flooded.
Update, 9:27 a.m.
Galveston has canceled all public transit services because of flooding, the city announced.
The National Weather Service has received reports of street flooding in the area around Ball High School in Galveston.
Southern Galveston County is under a flash flood warning until 10:30 a.m., according to the National Weather Service is League City.
A warning means flooding is happening or is imminent.
The warning went into effect a 8:36 a.m.
Moderate to heavy rain will cause some streets to flood, according to the weather service.
The warning includes all of Galveston Island, Jamaica Beach, Pelican Island, Crystal Beach and Port Bolivar.