With Hurricane Lee expected to pass offshore of Martha’s Vineyard Saturday, the National Weather Service has issued a tropical storm warning for Dukes County. The storm could hit the Island with tropical storm-force winds within the next 36 hours.

The Island was previously under a tropical storm watch, a lower level advisory. The storm, now a category 1 hurricane, was about 750 miles south of Nantucket Thursday afternoon.

Wind speeds from 25 to 35 miles per hour, with gusts up to 55 miles per hour, were predicted for the Island in a weather service warning on Thursday morning, with the potential to uproot trees and cause scattered power outages.

Storm surges of up to two feet above ground may occur in some areas, according to the weather service. Between one and three inches of additional rainfall is expected.

The weather service plans to issue another local statement around 6 p.m. this evening, or earlier if conditions make it necessary.

The Steamship Authority is anticipating disruptions to the Nantucket route Friday evening, and cancellations for both routes  Saturday. Cancellation fees for Friday and the weekend will be waived.

The Island Queen ferry has canceled all trips on Friday and Saturday. Hy-Line ferries to the Vineyard and the inter-Island ferry to Nantucket have also been canceled.

The Trustees of Reservations said it would close Cape Pogue Wildlife Refuge, Leland Beach and Wasque starting at 4 p.m. Friday and reopen them only after assessing the post-storm conditions.