Hurricane Harvey weakened Saturday as it moved along the Texas coast, saturating the state’s coastal area with heavy rain.

The storm blew onto shore as a powerful Category 4 hurricane, bringing with it 130 mph winds and the potential for severe flooding. By Saturday morning, the storm was downgraded to Category 1, but still posed a threat as it moved slowly along Texas’ coast.

The National Hurricane Center said it expects Harvey to cause “catastrophic flooding” over the next few days. The storm would likely weaken further to a tropical storm later Saturday, the center added.

Forecasts called for Harvey to move along Texas and up through Louisiana, with storm surges of 13 feet and more than three feet of rain expected in some areas.

More than 200,000 people were without power, according to NBC News.

Harvey, the most powerful storm in over a decade to hit the mainland United States, made a first landfall northeast of Corpus Christi, Texas, around late on Friday with maximum winds of 130 miles per hour.

In a sign of its lumbering movement, it then made a second landfall nearby three hours later.

Harvey was downgraded to a Category 1 hurricane by the National Hurricane Center early on Saturday as it moved slowly over parts of Texas at about 6 mph. Its maximum sustained winds were clocked at 80 mph. As of 8 a.m. ET, the storm was about 20 miles west-southwest of Victoria, Texas.

President Donald Trump said late Friday night that he signed a disaster declaration at the request of Texas Gov. Greg Abbott. Saturday morning, the president tweeted words of encouragement for the Federal Emergency Management Agency while noting that he was monitoring the situation from Camp David.

The Associated Press and Reuters contributed to this report.