Hurricane Harvey was upgraded to a Category 4 storm on Friday.

Harvey, which will be the first major storm to hit the U.S. since 2005, is gathering strength as it head up to the south coasts of Texas and Louisiana from the Gulf of Mexico.

It is expected to cause extreme damage and flooding.

A Category 4 storm, according to the Saffir-Simpson Hurricane Wind Scale, is considered a "major" hurricane and has sustained winds between 130 miles per hour and 156 mph.

The National Hurricane Center, says a Category 4 hurricane has the potential to cause "catastrophic damage to occur."

"Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months," the National Hurricane Center website explains.

Harvey is expected to make landfall on Friday evening or Saturday morning.

President Trump tweeted that the Huricane is "getting much bigger and more powerful than projected."

During the White House press briefing on Friday, homeland security adviser Tom Bossert said that Trump is prepared to use all the resources the White House has to offer to help the affected states. He also said "now is not the time to lose faith in your government institutions."