Rafael has strengthened into a hurricane as it moves through the southern Caribbean Sea.

The category 1 storm has maximum sustained winds of 80 mph and will pass over the Cayman Islands overnight. It's forecast to be near or over western Cuba Wednesday, and move into the Gulf of Mexico later in the day.

Forecasters at the National Hurricane Center say a “steady to rapid intensification” is expected during the next 18 hours and it's predicted to be a category 2 storm when it strikes western Cuba with "damaging hurricane-force winds, a dangerous storm surge, and destructive waves."

Heavy rainfall is predicted through early Thursday across Jamaica, the Cayman Islands, and parts of Cuba. Isolated totals up to ten inches are anticipated across higher terrain, which could lead to flash flooding and mudslides.

A tropical storm warning is in effect for the Lower and Middle Florida Keys and the Dry Tortugas where up to three inches of rain is forecast. A few tornadoes are possible Wednesday over the Keys and inland Southwest Florida.

While additional strengthening is forecast, the storm is predicted to weaken due to wind shear and cooler waters after it enters the Gulf of Mexico. Meteorologists caution it is too soon to determine what, if any, impacts Rafael could bring to portions of the northern Gulf Coast.