MIAMI -- Hurricane Isaias is expected to strengthen from a Category 1 to a Category 2 hurricane as it crosses over the Bahamas Friday and Saturday, lashing the still-recovering islands with up to 100 mph sustained winds.
According to the National Hurricane Center's 8 a.m. update, Isaias is about 340 miles southeast of Nassau and maintaining 80 mph winds.
Southeast Florida from Ocean Reef north to the Sebastian Inlet and Lake Okeechobee remain under tropical storm watches, and the hurricane center predicted South Florida could see several inches of rain and tropical-storm-force winds over the weekend.
Forecasters have been uncertain about Isaias' track and intensity, which is harder to predict, from the beginning. Thursday night, the forecast rapidly shifted from expecting a weak Category 1 by Saturday morning to a powerful Category 2.
Forecasters said some of that strengthening comes from the warm waters near the Bahamas, which are running three to four degrees above normal. Higher sea surface temperatures are one of the main ways climate change is affecting hurricane formation, and the record-setting heat seen in this region over the summer is one of the reasons scientists predicted this would be an active hurricane season.
The expected path has also flip-flopped across Florida's coasts and the Bahamas several times this week, although models generally seem in consensus that Isaias' path will take it between Florida and the Bahamas next.
"Some strengthening is possible today, and Isaias is expected to remain a hurricane for the next few days," and while there appears to still be some "uncertainty" in the storm's track, there is a "notable chance of a hurricane moving close to the U.S. East coast, so the forecast continues to show that scenario," forecasters wrote in the advisory.
According to the National Weather Service, the strongest winds in Florida will be felt from Pompano Beach to Palm Bay, where there's potential for winds from 58 mph to 73 mph. Miami-Dade and most of Broward are predicted to see winds from 39 mph to 57 mph.
Homestead to West Palm Beach could see about a foot of storm surge, and Homestead to Melbourne could see flooding rain. The hurricane center predicted that South Florida to east Central Florida could see two to four inches of rain, with some spots seeing six inches.
Miami-Dade County said Thursday it had everything prepared to open 20 hurricane shelters, but it does not plan on opening any, so far avoiding a test of the county's planned provisions to enforce social distancing and screen for the coronavirus at shelters.