Updated, 3:07 p.m. | The possibility of at least a modified transit shutdown in New York next week in the face of Hurricane Sandy loomed large on Friday, with winds expected to be above the range that would prompt the Metropolitan Transportation Authority to halt service.
The National Weather Service is predicting sustained winds of 40 to 50 miles an hour starting late Monday with gusts possibly in the 70s. The transportation authority’s hurricane plan “calls for an orderly shutdown of service before the arrival of sustained winds of 39 mph or higher.”
The authority has not yet decided if it will suspend some or all service, but said that “ample notice” would be provided once a decision was reached.
“Our first priority is always safety, and the M.T.A. is taking no chances with the safety of our customers, our employees and our equipment,” said the agency’s chairman, Joseph J. Lhota. “We are hoping for the best, but preparing for the worst. Whatever happens, we’ll be ready.”
The authority undertook an unprecedented shutdown of the subway system in August 2011, in advance of Tropical Storm Irene.
The present storm’s path across the Northeast is far from certain, but wherever the storm makes landfall, the weather service said, the New York metro area will very likely see at least 4 inches of rain and tropical storm-force winds, meaning above 39 miles an hour.
The storm is currently predicted to make landfall somewhere around Delaware, but if it turns north, the New York area could see 10 inches of rain, weather service meteorologists said on a call to reporters. A northward turn could also mean heavy river flooding instead of the flash floods that are currently expected.
Forecasters are expecting Hurricane Sandy’s path of damage to be much wider than Irene’s was last year. And wherever the storm ends up meeting the coast, the tidal surges will be bigger than Irene’s.
“Somebody is going to get a significant surge event out of this system, but it’s just too soon to say who that’s going to be,” said James Franklin, the branch chief for the National Hurricane Center. “We’ll be seeing numbers higher than Irene for somebody.”
Forecasters stressed that this far in advance, the error range for tracking the storm is about 200 miles. In the New York region, Mr. Franklin said, “This far out all I can tell you is that tropical storm force winds can be expected.”
In New York, officials were busy making preparations.
Mayor Michael R. Bloomberg urged New Yorkers to stay out of city parks starting on Sunday, and to stock up on basic supplies. “This is a large, unpredictable storm, so be prepared for possible outages,” he said at a news conference Friday afternoon.
The Buildings Department ordered all outdoor work at construction sites to halt at 5 p.m. Saturday.
The transportation authority has already cancelled most of its scheduled weekend construction projects except for on the 7 and J lines, where the work will be done on Saturday only.
The authority said an incident command center would be activated at 8 a.m. on Sunday. The center will include “customer advocates” — a position created after a review of the agency’s operations during Tropical Storm Irene — who will “ensure that all decisions made during the event will reflect a focus on customers,” according to the authority.
Contingency plans include the removal of trains from flood-prone outdoor yards and the placing of sandbags and tarps over subway grates vulnerable to flooding. In recent years, the authority said, many station entrances and grates in low-lying areas have been modified to be raised above street level.
On the Long Island Rail Road, extra crews could be dispatched to remove crossing gates before the storm if necessary, in a bid to protect the gates from high winds and help facilitate a quicker recovery after the storm. Service must be suspended if the gates are removed.
Teams were also inspecting the authority’s bridges and tunnels, clearing them of debris. If sustained winds reach 50 miles per hour or more, in wet or dry conditions, the authority said that certain vehicles would be barred from using its crossings, including motorcycles, tractor trailers, trucks with open backs, and vehicles carrying plate glass.
If the winds exceed 60 miles per hour, the authority said it could close one or more bridges to all traffic.