Hurricane Irma has strengthened to a Category 5 storm, and catastrophic damage is possible in the Florida Keys and southern Florida this weekend as a second storm has formed behind it.

Irma was packing 185 mph winds and gusts of more than 200 mph as of 2 a.m. ET Wednesday, and is expected to continue churning with deadly hurricane-force winds and a dangerous storm surge across a wide swath of the Caribbean this week before moving toward southern Florida, according to the National Hurricane Center (NHC).

The dangerous storm made landfall in Barbuda around 2 a.m. on Wednesday and is moving west-northwest at 15 mph. Hurricane watches and warnings have been issued across Puerto Rico, the Dominican Republic, Haiti, Turks and Caicos, Cuba and the Leeward Islands.

Meanwhile, Tropical Storm Jose has formed over the open Atlantic, following closely behind Irma, the NHC said Tuesday. Jose could become a Category 2 hurricane as it brushes the northeastern-most Caribbean islands at the end of the week. However, Jose poses no threat to the U.S. or Puerto Rico as of Tuesday.

The NHC warned that residents in the Leeward Islands, already expected to face Irma, "should monitor the track" of Jose.

PHOTO: A graphic from the National Hurricane Center shows Tropical Storm Jose forming behind Hurricane Irma, Sept. 5, 2017. (NOAA) More

The NHC on Tuesday called Irma the strongest hurricane in the Atlantic basin outside of the Caribbean Sea and Gulf of Mexico in NHC records.

By Sunday around 8 a.m., outer bands from Hurricane Irma are expected to reach the Florida Keys with winds of 145 mph as a Category 4 hurricane. Irma's center is forecast to move over Key West on Sunday afternoon.

It is still unclear whether the storm will track up the east or west coast of Florida. If Irma travels up Florida's west coast, it would present worst-case scenarios for Gulf cities from Naples to Tampa. If the storm travels up Florida's east coast, the "bad" side of the storm would remain off-shore, but it could later make landfall somewhere between Savannah, Georgia, and Charleston, South Carolina.

Florida Gov. Rick Scott on Monday declared a state of emergency for every county to ensure that local governments have enough "time, resources and flexibility to get prepared for this dangerous storm," according to a statement from his office.

Mandatory evacuation orders have been ordered for Monroe County, which includes the Florida Keys, beginning on Wednesday, but cars were already streaming out of the region on Tuesday evening. Officials also anticipate evacuation orders for low-lying portions of Miami-Dade County, including Miami Beach, by late Wednesday or early Thursday.

President Donald Trump approved Scott's declaration for a pre-landfall emergency for the entire state of Florida, the governor said in a press conference Tuesday evening.

Scott said Tuesday that it is important that Floridians keep a close eye on the storm and "do not sit and wait to prepare."

Scott has deployed 100 members of the Florida National Guard, and nearly 7,000 troops will be reporting for duty in the coming days, the governor said.

The American Red Cross is sending 1,000 volunteers to Florida, Scott said.

"In Florida, we always prepare for the worst and hope for the best," Scott said, "and while the exact path of Irma is not absolutely known at this time, we cannot afford to not be prepared."

PHOTO: Wes and Davina Hardin of Palm Bay are buying plywood and other hurricane supplies in preparation for Hurricane Irma on Sept. 4, 2017, at the Melbourne Lowe's Home Improvement Store on Minton Road, Fla. (Tim Shortt/Florida Today via USA Today) More

The Monroe County School District is shuttering schools Wednesday, the county added. Schools in several other Florida counties, including Miami-Dade and Broward, will be closed Thursday and Friday, Scott said.

The University of Miami has canceled classes for Wednesday, Thursday and Friday, the school announced Tuesday.

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