Hurricane Lee reached Category 5 strength on Thursday night, less than 48 hours after it reached Category 1 status on Wednesday. The storm now has top sustained wind speeds of at least 160 mph.
The storm has organized and strengthened with remarkable speed, even by the standards of fast-developing hurricanes.
The National Hurricane Center defines rapid intensification as an increase in the speed of a storm's fastest sustained winds by 35 mph within a 24-hour period. In that time frame, Lee accelerated its top wind speeds by at least 55 mph.
Forecasters expect strengthening will continue through Thursday night and Friday thanks to low winds and high ocean surface temperatures.
Hurricane Lee gains strength in the Atlantic
Lee is expected to reach major hurricane status. The storm is still far out in the Atlantic and there are minimal risks to land.
Forecasters are also confident that the storm's path will continue west-northwest, north of the Leeward Islands, for the next five days. In that time, the main threat to land will continue to be dangerous surf and rip currents, affecting parts of the Northern Caribbean by Friday, and later the U.S. East Coast.
It's too early for forecasters to speculate on Lee's trajectory as it approaches the U.S. mainland. In the meantime, they encourage people to stay up to date with information from their local weather offices.