HOUSTON (Reuters)

The Gulf Coast of Texas and Louisiana was bracing on Monday (September 13) for the arrival of Tropical Storm Nicholas, which was expected to batter the region with life-threatening storm surge, flash flooding and gusty winds.

The storm, carrying winds of 97 kilometres/hour, was moving erratically as it headed northward about 225 kilometres south of the southern coast of Texas, the National Hurricane Center (NHC) said in a Monday morning bulletin.

It was forecast to move ashore along the southern or central coast of Texas late on Monday afternoon or evening.

The National Weather Service issued storm surge, flood and tropical storm warnings and watches that were in effect until at least Tuesday for the area that reached from the southern tip of Texas across the state’s Gulf coast and into Louisiana.

“This is a life-threatening situation,” the NHC said. “Persons located within these areas should take all necessary actions to protect life and property from rising water.”

Nicholas is the second storm in as many weeks to threaten the US Gulf Coast. Hurricane Ida wreaked havoc in late August, killing more than two dozen people and devastated communities in Louisiana near New Orleans.

Houston Mayor Sylvester Turner urged the city’s 2.3 million residents to stay at home starting on Monday evening. Parts of the city were expected to get eight inches (20 cm) or even more rain, according to the forecast.

“Take things seriously and prepare,” he said during a news conference. “This is primarily a rain event and we don’t know how much rain we will be getting.”

Houston, the fourth most populous city in the United States, was devastated in 2017 when Harvey, a Category 4 hurricane, slammed Southwest Texas, dropping up to 40 inches of rain in some sections and killing more than 100 people.

Houston Independent School District cancelled classes for Tuesday, while dozens of districts in Texas shut down Monday.

Waves stirred up by Nicholas neared 12 feet (3.7 m) in height were reported outside of Port Aransas, near Corpus Christi, Texas, with wind gusts up to 54 mph about 40 miles east of Padre Island, the National Weather Service said.

Winds were expected to remain at 60 mph with higher wind gusts. Rainfall totals of up to 16 inches and possibly 20 inches in some isolated areas were in the forecast for coastal Texas.

Nueces County, which includes the city of Corpus Christi, issued a disaster declaration on Monday, saying that the community was under a threat of imminent disaster, injury and loss of life or property due to the anticipated storm.

But on Monday afternoon, conditions in the coastal city of Galveston were still relatively calm, although wind gusts reached nearly 50 mph.

“It ain’t even raining,” said Mike Garcia, manager of the Gumbo Diner. “The water’s choppy, but we have a full restaurant.”

Royal Dutch Shell on Monday began evacuating staff from a U.S. Gulf of Mexico oil platform and other firms began preparing for hurricane-force winds.