(TAP) - Heavy rains fell across the Gulf Coast of Texas and Louisiana on Tuesday as tropical storm Nicholas strengthened into a hurricane before making landfall, bringing the threat of widespread flooding, power outages and storm surges.

Nicholas was some 20 miles (30 km) northeast of Matagorda, Texas as of 1 a.m. central time (2 a.m. eastern), heading northeast with maximum sustained winds of 75 miles per hour (120 kph), the National Hurricane Center said in a bulletin early on Tuesday. It made landfall along the Texas coast, NHC said.

U.S. President Joe Biden declared an emergency for Louisiana and ordered federal assistance to supplement local response efforts due to conditions resulting from Nicholas, the White House said.

"It will be a very slow-moving storm across the state of Texas that will linger for several days and drop a tremendous amount of rain," Texas Governor Greg Abbott said.

Abbott declared states of emergency in 17 counties and three cities. He said boat and helicopter rescue teams had been deployed or placed on standby.

Nicholas is the second hurricane in recent weeks to threaten the U.S. Gulf Coast. Hurricane Ida wreaked havoc in August, killing more than two dozen people and devastating communities in Louisiana near New Orleans.

Houston Mayor Sylvester Turner, citing flood warnings, urged the city's roughly 2.3 million residents to stay off streets and highways.