This is Thursday’s storm coverage. Read the latest with Friday’s live updates on Hurricane Irma »

Hurricane Irma, an “extremely dangerous” Category 4 storm with sustained winds of up to 155 miles an hour, continued to tear through the Caribbean on Friday, moving through the Bahamas and along the northern coast of Cuba, the National Hurricane Center said.

The death toll from the storm was at least seven as of Thursday afternoon, but the authorities warned that the number could rise as emergency crews reached flooded areas and as communications improved. The hurricane is expected to hit the Florida Keys and South Florida starting Saturday evening, said Kevin Scharfenberg, a meteorologist with the National Weather Service.

A second storm, Jose, strengthened into a Category 3 hurricane in the Atlantic Ocean and could hit Antigua and Barbuda, which have suffered extensive flooding and wind damage from Irma, according to the National Hurricane Center.

In Florida and Georgia, officials issued mandatory evacuation orders for coastal and some inland areas, leading to gas shortages and heavy traffic on local highways. The National Hurricane Center issued a hurricane warning for South Florida, the Florida Keys, Lake Okeechobee and Florida Bay and a storm surge warning for South Florida and the Florida Keys.

• Half of the 100,000 residents of Antigua and Barbuda have had their homes destroyed or heavily damaged, the prime minister said.

• The governor of Puerto Rico said at a news conference that electrical service had been restored to 144,000 households — which still leaves nearly a million in the dark.

• Officials in Florida have issued evacuation orders, including mandatory ones for all of Monroe County and for parts of Miami-Dade, Broward, Palm Beach, Pinellas and other counties.

• Irma’s 185-m.p.h. winds persisted for more than 24 hours, the longest period ever recorded. The French weather service described it as the most enduring superstorm on record.