As the remnants of Tropical Storm Fred raced out of western New England on Thursday, leaving an inch of rain at Pittsfield Municipal Airport, forecasters acknowledged a “tricky outlook” as potential Hurricane Henri could threaten the New England coast on Sunday.

As of Thursday evening, the National Weather Service forecast for the Berkshires called for chance of rain Sunday and Monday, followed by fair weather through mid-week, along with late summer warmth and humidity by day and mild, muggy nights.

However, Tropical Storm Henri, lurking in the western Atlantic about 800 miles south of Nantucket with top winds of 65 mph, was gaining strength as it moved westward at 10 mph. It is forecast to intensify into a hurricane by Friday night with additional strengthening over the weekend, according to advisories from the National Hurricane Center.

The forecast track indicates Henri will remain well offshore through Friday, but is expected to approach southern New England late Saturday.

The storm is forecast to be near the Northeast coast on Sunday and Monday, and the risks of storm surge, wind, and torrential rain are increasing for southern New England and eastern Long Island, N.Y.

Coastal areas, including the Cape and the Islands, could see Category 1 hurricane-force winds above 75 mph. Also, 2 to 5 inches of rain could fall over southeastern New England Sunday into Monday, with isolated maximum totals near 8 inches. Heavy rainfall may result in areas of flash, urban, and small stream flooding.

In the Berkshires, top winds could reach 20 to 30 mph on Sunday.

The center of Henri, probably downgraded to a tropical storm, is expected to be over Nantucket and Martha’s Vineyard on Sunday night before moving further offshore toward Nova Scotia.

Beachgoers and other vacationers were advised to beware of heavy surf and rip currents, which have killed more people year-by-year since 2010 than lightning strikes and impacts from extreme cold combined, according to the National Oceanic and Atmospheric Administration.

Travelers planning weekend jaunts to New England coastal destinations are urged to keep a wary eye on the forecast as it’s adjusted to reflect Henri’s most likely track.

Clarence Fanto can be reached at cfanto@yahoo.com, on Twitter @BE_cfanto or at 413-637-2551.