Snow has begun to blanket the region, with weather models predicting up to 16 inches, 45 mph wind gusts and zero-visibility whiteout conditions Friday into Saturday.
The storm also will wallop the region farther north, from northern Westchester to Orange, Ulster and Dutchess counties, but the latest forecast information on Thursday indicated that New York City and Westchester County will get the worst of it.
The warnings prompted several towns and cities to declare snow emergencies even before the first flurries. Officials already were warning people to stay home and avoid roads as the storm intensifies Friday afternoon.
State Police warned they would "sporadically" close stretches of Interstate 84, Interstate 684 and the Taconic State Parkway.
"All vehicles abandoned on the roadway will be subject to immediate impoundment," State Police Maj. Michael Kopy said.
Commuters will get some help from Metro-North, which will put extra trains in service on Friday afternoon. People who head in to work on Friday should plan to leave early -- the extra trains will run until 5 p.m., and the MTA said it cannot guarantee train service after that as the storm intensifies.
"There's been no changes in those plans at the moment, but we are continuing to monitor the situation," MTA spokesman Aaron Donovan said early Friday.
He added that there is a possibility of subway, train and bus service being discontinued Friday evening when the storm intensifies.
Schools were planning early dismissals, a rally for a Super Bowl hero was postponed and utility companies were adding out-of-state repair crews Thursday as the blustery nor'easter named Nemo bore down on the Hudson Valley.
"We have enough salt. We have enough brine. We have enough fuel," said Steve Altieri, administrator in the Town of Mamaroneck. "The town is ready for the storm."
POWER OUTAGES LIKELY
The National Weather Service warned of "scattered power outages" and issued winter storm watches for Westchester, Rockland, Putnam, Orange, Dutchess and Ulster counties through 1 p.m. Saturday.
"We and other utilities have calls for mutual aid from other parts of the country," said a Con Edison spokesman.
Orange & Rockland declared a companywide storm watch and said it likely would be upgraded to a storm alert at 8 a.m. Friday.
Still, the scope of the power outages likely will be limited, said News12 meteorologist Brysen Van Eck, with the strongest winds east of the Hudson River.
"This isn't [superstorm] Sandy," Van Eck said. "There isn't going to be widespread trees across highways. It won't take us days to recover."
In Kingston, where highway crews are responsible for more than 120 miles of roads, the plan is to plow all roads as the snow falls. If the snowfall is too intense to keep up, the city's plows will fall back to plowing predetermined snow routes. Michael Schupp, the city's superintendent of public works, said the priority is to make sure emergency vehicles can still make it across town during the storm.
"If the storm becomes too intense, obviously then we ask people to stay off the roads so we can keep them clear for emergency response," Schupp said.
The City of Newburgh declared a snow emergency, to take effect at 6 p.m. Thursday, putting alternate-side-parking regulations into effect.
Public schools in the Yonkers and Edgemont districts have announced they will dismiss early on Friday. NJ Transit has urged customers to consider traveling early Friday because of potential disruptions in the afternoon.
The Federal Emergency Management Agency canceled disaster recovery workshops scheduled for Friday and Saturday in Valhalla and Stony Point, respectively. The National Weather Service also issued a coastal flood watch for southern Westchester through midnight Saturday.
Van Eck said tides could run 3-5 feet above normal levels.
The snowfall is expected to start slowly, around daybreak Friday, intensifying Friday afternoon and continuing until about 9 a.m. Saturday, Van Eck said.
"People who need to get to work on Friday can," said the News12 meteorologist. He cautioned that roads will be hazardous by midafternoon. "From 3 p.m. to 9 p.m., if you can stay off the roads, that would be your best bet."
The Hudson Valley can expect 8-16 inches of snow by Saturday afternoon, Van Eck said.
Road crews in Yonkers and other municipalities were pretreating the roads Thursday in preparation for the storm. Snow shovels and sidewalk salt were in high demand at hardware stores.
For Con Edison and other area utilities, that means mutual-aid crews are unlikely to come from the north.
"New England looks like it will get hit worst," the Con Edison spokesman said.
Once the snowfall ends, the weekend is expected to clear in the Hudson Valley, with high temperatures of about 30 degrees Saturday and 33 degrees Sunday. A warming trend is expected to arrive Monday and Tuesday, with highs in the 40s. Scattered showers are forecast for Monday.