About two to four inches of snow and sleet are expected to fall on the city by mid-morning, and then up to two-tenths of an inch of freezing rain will top the snowfall with ice.

Roads and sidewalks are expected to be very slippery and traffic will be slowed down.

Later tonight, a second wave of wintry precipitation will fall on the city. Sleet and freezing rain will fall overnight, followed by almost an inch of rain that will fall by Wednesday evening.

New Yorkers are urged to take mass transit and to avoid driving on roads during and immediately after the snow storm. They should also allow for extra time to get around, take caution on transit platforms and stairs and carefully board trains and buses.

The Metropolitan Transportation Authority prepared for the bad weather by sending de-icing trains to keep the rails in working order.

MTA officials urge New Yorkers to check www.mta.info for the latest transit service changes.

City transportation officials have suspended alternate side parking and parking meter rules for today.

The Department of Sanitation issued a snow alert effective at 1:30 a.m. that makes the agency load salt spreaders and attach plows to vehicles.

Also, the Department of Buildings warned homeowners, contractors and builders to remove ice and snow from roofs and to prepare buildings and construction sites for the upcoming storm.