BOSTON, Massachusetts (CNN) -- Hurricane Bill spun northward toward the New England coast Saturday with wind and rain as officials warned beach lovers to head indoors for the night.
Signs at Lighthouse Beach at Chatham, Massachusetts, warn beach-goers Saturday of rough waters.
At 11 p.m., the center of the Category 1 storm was about 195 miles southeast of Nantucket, Massachusetts, the National Hurricane Center said. Forecasters said the island can expect 1 to 2 inches of rain, and Outer Cape Cod and Martha's Vineyard may receive only an inch.
Swells as high as 19 feet are expected Monday night, Coast Guard Petty Officer Jordan Berryman told CNN in Chatham, Massachusetts.
"It's been generally calm but tonight we recommend that everybody stay off the beach," he said.
The storm continued its northerly pace of nearly 25 mph. A gradual change to the north-northeast is predicted for Sunday. Bill's sustained winds remained at 100 mph, with higher gusts.
"The surf is definitely big," Emily Chibaro of Nantucket told CNN Radio Saturday. "The south shore part of the island is closed off to all people on the island." iReport.com: Are you bracing for Hurricane Bill?
A gradual weakening is expected Saturday night and Sunday as the hurricane moves north of the Gulf Stream, a swift, warm Atlantic Ocean current.
The core of the storm should pass New England offshore Saturday night, and approach Nova Scotia on Sunday.
Massachusetts Gov. Deval Patrick said tropical-force winds from the outer bands of the storm were forecast to hit his state at 9 p.m. ET, earlier than expected. The speed of tropical-force winds range from 39 mph to 73 mph. Watch the waves crash on Massachusetts beach »
A tropical storm warning was issued for the coast of Massachusetts from Woods Hole to Sagamore Beach, including the islands of Martha's Vineyard and Nantucket.
The hurricane itself is predicted to stay offshore, the hurricane center said.
The most intense period of the storm should be between midnight and the predawn hours of Sunday, the governor told reporters in a conference call.
Patrick cautioned boaters to expect high seas and to avoid the area around Cape Cod. Forecasters have warned of dangerous riptides, or undertows, along the New England coast and points north.
"Waters will be unsafe even for strong swimmers," the governor warned.
Rip currents, or riptides, are strong seaward flows of water that occur where there's a break in the shoreline. They are difficult to detect. Watch CNN's Bonnie Schneider talk about rip currents »
Patrick said advisories will be posted, and beaches on the cape were closed. He urged residents to stay home.
President Obama and his family are scheduled to arrive Sunday for a vacation at Martha's Vineyard.
"We look forward to welcoming him to Massachusetts as soon as he can safely get here," Patrick said.
Hurricane Bill skirted Bermuda, leaving rain in its wake. The tropical storm warning for Bermuda was discontinued.
Canada's weather service, Environment Canada, issued a tropical storm warnings and hurricane watches for parts of Nova Scotia. Watch how Nova Scotians are preparing for Bill »
A tropical storm warning means tropical storm conditions are expected somewhere within the warning area within 24 hours. A watch means conditions are expected to change within 36 hours.
Total rain accumulations of 3 to 5 inches with isolated amounts of 7 inches are expected near the track of Bill across Nova Scotia, Prince Edward Island and Newfoundland.
CNN's Susan Candiotti and CNN Radio's Brendan Gage contributed to this report.