Nearly one million customers are without power in Texas as Hurricane Beryl lashed Houston with heavy rains and powerful winds on Monday.
More than 1,000 flights have been cancelled at Houston's two airports, according to tracking data from FlightAware.
High waters quickly began to close streets across Houston and flood warnings were in effect across a wide stretch of the Texas coast.
The National Weather Service expected Beryl to weaken to a tropical storm Monday and a tropical depression Tuesday, forecasting a turn to the northeast and increase in speed Monday night and Tuesday.
The storm reached the US after leaving a trail of destruction over the last week in Mexico and the Caribbean.
The storm's centre hit land as a Category 1 hurricane around 4am Central Standard Time about 85 miles southwest of Houston with top sustained winds of 80 mph (128.7 kph) while moving north at 12 mph (19.3 kph), the National Weather Service reported.
High waters quickly began closing roads around Houston, which was again under flood warnings after heavy storms in recent months washed out neighborhoods and knocked out power across the nation's fourth-largest city.
Beryl dumped soaking rains across Houston after coming ashore and was expected to bring damaging winds into East Texas, near Louisiana, as the storm pushed north after making landfall.
"Beryl's moving inland but this is not the end of the story yet," said Jack Beven, senior hurricane specialist at the National Hurricane Center.
Beryl strengthened and became a hurricane again late Sunday. The storm had weakened after leaving a path of deadly destruction through parts of Mexico and the Caribbean.
A hurricane warning remains in effect for the Texas coast from Mesquite Bay north to Port Bolivar, the center said.
The storm's centre is expected to move over eastern Texas on Monday and then through the lower Mississippi Valley into the Ohio Valley on Tuesday and Wednesday, the weather service said.
People on the Texas coast boarded up windows and left beach towns under an evacuation order. As the storm neared the coast Sunday, Texas officials warned of power outages and flooding but also expressed worry that not enough residents and beach vacationers in Beryl's path had heeded warnings to leave.
"One of the things that kind of trigger our concern a little bit, we've looked at all of the roads leaving the coast and the maps are still green," said Texas Lt. Gov. Dan Patrick, who is serving as the state's acting governor while Gov. Greg Abbott is travelling overseas.
"So we don't see many people leaving."
Tropical storm winds extended 115 miles (185 kilometers) from the center and the hurricane center warned residents to be prepared for possible flash flooding in parts of middle, upper and eastern Texas as well as Arkansas as the storm gradually turns to the north and then northeast later Monday.
Along the Texas coast, many residents and business owners took the typical storm precautions but also expressed uncertainty about the storm's intensity.
The earliest storm to develop into a Category 5 hurricane in the Atlantic, Beryl caused at least 11 deaths as it passed through the Caribbean on its way to Texas.
The storm ripped off doors, windows and roofs with devastating winds and storm surge fueled by the Atlantic's record warmth.
Three times during its one week of life, Beryl has gained 35 mph (56 kph) in wind speed in 24 hours or less, the official weather service definition of rapid intensification.
Beryl's explosive growth into an unprecedented early whopper of a storm indicates the hot water of the Atlantic and Caribbean and what the Atlantic hurricane belt can expect for the rest of the storm season, experts said.
Texas officials warned people along the entire coastline to prepare for possible flooding, heavy rain and wind. The hurricane warning extended from Baffin Bay, south of Corpus Christi, to Sargent, south of Houston.
The White House said Sunday that the Federal Emergency Management Agency had sent emergency responders, search-and-rescue teams, bottled water and other resources along the coast.
Beryl battered Mexico as a Category 2 hurricane last week, toppling trees but causing no injuries or deaths before weakening to a tropical storm as it moved across the Yucatan Peninsula.
Before hitting Mexico, Beryl wrought destruction in Jamaica, Barbados and St. Vincent and the Grenadines. Three people were reported dead in Grenada, three in St. Vincent and the Grenadines, three in Venezuela and two in Jamaica.
