Forecasters were still predicting Tuesday night that Hurricane Earl will come dangerously close to the Cape and Islands.
If the storm does not deviate from its current track, it is expected to be within 50 to 100 miles southeast of Nantucket by Friday night, according to Mike Ekster, National Weather Service meteorologist.
Before Earl arrives, Massachusetts remains in the midst of what looks to be a five-day heat wave, with temperatures predicted to be in the mid 90s on Wednesday and Thursday, said Kevin Cadima, another meteorologist for the National Weather Service in Taunton.
The temperatures should drop to around 80 on Friday, but humidity will rise with clouds and possibly rain expected as Earl approaches the area, Cadima said.
On Nantucket, some boaters were pulling their vessels from the marina ahead of Earl, said Bill Pittman, local director of the Massachusetts Emergency Management Agency, or MEMA, for the island. Pittman said churning, high surf and strong rip currents are of most concern for the island.
‘‘The biggest hazard to people at this point is wandering into the water because of the rip currents and such,’’ Pittman said.
Currently, there is no evacuation planned for the island, Pittman said.
Nantucket authorities are advising residents to make sure they have proper food and enough water if the power goes out and checking in on homes that are in danger due to beach erosion.
Pittman said access to clean drinking water is of particular importance due to the large number of homes that use wells on the island, which could be tainted if flooding occurs.
Overall, Pittman remained optimistic about Earl’s potential. ‘‘If it stays on its current track, I think we’re in good shape,’’ he said.
Earl remained a Category 4 storm on Tuesday with maximum sustained winds of 135 miles per hour. It was about 130 miles northeast of Grand Turk Island, north of the Dominican Republic, and 910 miles south-southeast of Cape Hatteras, N.C. Ekster said he expected the storm to be about 300 miles north of the Central Bahamas by early on Wednesday.
If Earl stays on its current track, it will reach the region Friday or Friday night.
Cape Cod and the islands are expected to be hit with the worst weather, with winds of up to 73 miles per hour, high waves, and dangerous rip currents, said Dan Kottlowski, senior meteorologist for AccuWeather.com.
Kottlowski said Earl will probably dump rain and send a steady breeze across other parts of Eastern Massachusetts.
But with a margin of error of 100 or so miles for the storm-track projections, it is possible that the hurricane could make landfall in Massachusetts, Kottlowski said.
‘‘There is a still a chance that the hurricane could track a little bit more to the west,’’ he said. ‘‘All of Massachusetts is in that area of uncertainty.’’
While most of Earl’s severe weather is expected to take place offshore, Ekster said, Massachusetts could see severe hurricane-related weather.
‘‘There’s a lot of uncertainty; we are still 3, 3-and-one-half days out,’’ Ekster said Tuesday night. ‘‘We probably won’t know for sure what the exact track of the hurricane will be until late tomorrow or early Thursday. Although it’s a low probability, it’s still possible the Cape and Islands could take a hit.’’
State and federal officials urged East Coast residents to be vigilant of the storm’s progress and to be prepared for the worst-case scenario.
‘‘Over the next few days, things could change dramatically, for better or worse,’’ said Peter Judge, a spokesman for MEMA. ‘‘It’s very important for people to stay on top of it.’’
Judge warned inland residents not to disregard Earl.
In state history, the worst flooding during hurricanes has occurred in Central and Western Massachusetts, not on the coast, Judge said.
‘‘Obviously, if you live right along the coast, you have to deal with the storm surge, but a hurricane can impact the entire state,’’ Judge said. ‘‘It’s important for everybody to not just think of it as a coastal event.’’
The Federal Emergency Management Agency issued a statement Tuesday urging all East Coast residents to prepare their families and businesses for very severe weather.
‘‘Hurricane Earl should serve as a reminder to all of us of the importance of being prepared for hurricanes and other emergencies,’’ said Craig Fugate, FEMA administrator. ‘‘At FEMA, we’re taking steps to aggressively prepare, should a hurricane make landfall along the East Coast.’’
The US Coast Guard is also encouraging people along the coast to be prepared to evacuate if necessary.
‘‘The main thing is safety,’’ said Petty Officer Luke Clayton, Coast Guard spokesman. "Everyone needs to watch each other’s back.’’
Clayton said the Coast Guard is making preparations and securing its small boat stations to ensure it can adequately respond in the event of a hurricane.
Ekster said he expects Earl to decrease in strength to a Category 2 or 3 storm by the time it reaches New England.
According to the National Weather Service, a Category 3 hurricane has sustained winds of 111 to 130 miles per hour, while a Category 2 has winds of 96 to 110 miles per hour.
‘‘Hurricanes need very warm water, in excess of 80 degrees Fahrenheit, to survive,’’ Ekster said. ‘‘Once you get into cold water like we have up here, it slowly weakens.’’
Globe correspondent L. Finch and Martin Finucane of the Globe staff contributed to this report. Stewart Bishop can be reached at firstname.lastname@example.org.
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