Miami, Florida - Tropical Storm Idalia was strengthening in the Caribbean on Monday, buffeting southeastern Mexico with wind and rain, with forecasters predicting it will become a major hurricane before reaching Florida later in the week.

The storm, which is not forecast to make landfall in Mexico, will travel across western Cuba and the Gulf of Mexico before reaching northwest Florida, the US National Hurricane Center said.

Idalia was "intensifying as it approaches Cuba" and "life-threatening storm surge and dangerous winds (are) becoming increasingly likely for portions of Florida," the NHC said.

"Idalia is forecast to become a hurricane later today and a dangerous major hurricane over northeastern Gulf of Mexico by early Wednesday," the center's morning advisory said.

The NHC predicted Idalia will make landfall in Florida by 7:00 AM EDT Wednesday, in an image showing the storm's likely path.

Storm surge and hurricane watches have been issued for parts of Florida's coast and scattered flash flooding can be expected.

Governor Ron DeSantis has declared a state of emergency in 33 counties in preparation for the storm's arrival.

In the Mexican state of Quintana Roo, home to Cancun and other coastal tourist resorts, Idalia dumped rain and put a damper on one of the last weekends of summer vacation.

Heavy rainfall is expected across parts of the eastern Yucatan in Mexico and in western Cuba.

A week ago, Hilary, which at one point rose to a Category 4 hurricane on the five-point Saffir-Simpson scale, hit the state of Baja California on Mexico's Pacific coast as a tropical storm, causing one death and damaging infrastructure, before causing massive flooding in Southern California.

Hurricanes hit Mexico every year on both its Pacific and Atlantic coasts.

Scientists have warned that storms are becoming more powerful as the world gets warmer due to climate change.