Updated at 1:54 p.m. ET

Hurricane Michael is expected to strengthen rapidly over the next 24 to 36 hours and will be "a dangerous major hurricane when it reaches the northeastern Gulf Coast on Wednesday," the National Hurricane Center says.

The storm became hurricane status with maximum sustained winds of 75 mph in forecasters' update Monday morning, triggering warnings of a life-threatening storm surge that could hit the Florida Gulf Coast.

Florida Gov. Rick Scott issued a state of emergency for 26 counties on Sunday, as member station WFSU reports. The governor warned people who live in the Big Bend and Florida Panhandle to prepare for flooding and high winds. Emergency management officials in Tallahassee and Leon County also began distributing sandbags to residents.

Hurricane Michael was 20 miles southwest of the western tip of Cuba shortly before 2 p.m. ET Monday. It was moving slowly north at 7 mph — a speed that is expected to increase through Tuesday night.

A hurricane watch — meaning tropical-storm-force winds are possible within 48 hours — is in effect from the Alabama-Florida border to the Suwannee River in Florida, the National Hurricane Center said.

"Start preparing today," NHC Director Ken Graham told people in the storm's path, in a Facebook video update Monday. "You have some time tomorrow, but [as] you start looking at tomorrow night into Wednesday, things start to deteriorate rapidly."

A storm surge watch is in effect for a long swath of Florida's coast, from Navarre east of Pensacola to Anna Maria Island, south of Tampa Bay. Far inland, from the Florida Panhandle into Georgia and the Carolinas, rainfall totals are predicted to be up to 8 inches, with a foot of rain possible in isolated areas.

The hurricane's sustained winds are expected to hit at least 111 mph by Tuesday, making it a major hurricane — the designation for Category 3 storms and above, on the Saffir-Simpson wind scale.

Michael also poses an immediate threat to western Cuba, where it will pass as it heads into the Gulf of Mexico. Forecasters say the hurricane will also bring tropical storm conditions to parts of the Yucatan Peninsula, and predict the storm will take a relatively direct northerly route toward the Florida Panhandle.

As was the case with recent devastating hurricanes such as Florence and Harvey, forecasters say the biggest dangers for this storm come from the massive amounts of water Michael will bring, in the form of a storm surge and intense rainfall.

"Heavy rainfall from Michael could produce life-threatening flash flooding from the Florida Panhandle and Big Bend region into portions of the Carolinas through Thursday," the hurricane center said.

Michael has quickly gained strength since the National Weather Service issued its first bulletin on the system Saturday. It became a tropical storm a littler after noon on Sunday; less than 24 hours later, it was a hurricane.

Forecasters say the storm will gain more intensity through Tuesday, with a chance it will weaken somewhat as it nears land in Florida.

Even if Michael weakens after landfall, the hurricane center says, part of the system will keep circulating over water along the southeastern coast — a situation that will likely help Michael remain a tropical storm for the following 72 hours. After four days, hurricane experts say, the system should diminish and move off the mid-Atlantic coast.

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