Anyone wondering what happened to the blizzard forecast to blanket parts of Long Island and New York City can look west and north of us.
The storm’s track Tuesday was off what experts had prognosticated by 50 miles or so, with the low-pressure system skirting the Island and the city in its trip up the East Coast and into New England.
Still, meteorologists were quick to point out the nor’easter was a big one.
“The storm is there, the precipitation was there, the amount of precipitation is there,” said Tom Kine, meteorologist with AccuWeather in State College, Pennsylvania. “The people up in eastern Pennsylvania, northern Jersey and southeast New York and Connecticut, they are getting walloped and they are saying, ‘You know, great forecast.’ ”
On Long Island, though, the range of accumulated snow was between 2.9 and 4.5 inches in Suffolk County and hovered around 4 inches in Nassau County, according to the National Weather Service in Upton. New York City’s Central Park had 7.2 inches by 2 p.m.
What started as your typical snowfall had turned to sleet by late morning and progressively to rain.
“That’s the way Mother Nature wanted it,” Kine said.
There were more technical explanations, plus what meteorologists like Kine said is the uncertainty of any weather forecast.
John Murray, a meteorologist with the National Weather Service, described the event this way: “The storm system and the center of the low [pressure system] tracked closer to the coast and with that closer proximity to Long Island, more winds from the east brought in . . . a relatively warmer environment” from the sea surface.
This system also had more potential factors than the usual mix, said Nicholas Bassill, a modeler and meteorologist with the New York State Mesonet, a network of weather stations based at the University at Albany.
Models that factor in multiple weather measurements predicted a major storm as early as Saturday, but the track kept sliding west until the day before it was to arrive, a time by which a track prediction normally has become set, Bassill said.
Snowstorms result from the interactions between a cyclone miles off the ground and surface-level fronts, he said. The models in this instance were tracking three upper-level storms — one coming from Mexico and along the southeastern coast; one that moved from the Pacific Northwest and across the Tennessee River Valley; and another that moved across British Columbia and southern Canada toward Michigan.
“There were more moving parts in the atmosphere,” Bassill said. “I think this storm will be one that will be a pretty common research topic for people who are interested in improving models and forecasts and probably even improving how to communicate uncertainty to the public.”
Bill Korbel, chief meteorologist for News 12 Long Island, said he was among forecasters trying to relay changes as the track prediction moved, but many “people had gone to bed” Monday night before it became clear that the local snowfall would be smaller.
“For probably five days, we knew there was going to be a strong storm. The question was, again, would it take that path that would give us all snow or not?” Korbel said. “The storm kept tracking more and more to the left, which is more of a wet solution than a snow solution — at least for Long Island.”
Long Island’s forecast is further complicated, he said, because it is surrounded by water, which was warmer after a mild winter and contributed to the changeover from snow to sleet.
When weather predictions are in doubt around these parts, Korbel said, blame the ocean.