At nightfall on Monday, Philadelphia Mayor Michael Nutter declared a snow emergency — ordering that parked cars be moved to clear the city’s designated emergency routes ahead of what government forecasters predicted could be a “crippling” and “potentially historic” blizzard.
Prepare for a foot to 24 inches in eastern Pennsylvania and New Jersey, they warned. The governors of both states signed disaster proclamations in advance.
But shortly before midnight — when the snow arrived as a menace not a monster — came a mea culpa rarely seen in the meteorology world.
Gary Szatkowski, chief of the National Weather Service office that serves Mount Holly, N.J., and Philadelphia, offered a heartfelt public apology on Twitter.
Szatkowski, who according to his LinkedIn page has been with the National Weather Service for nearly 35 years, then wrote that the storm will still have great impacts to the Northeast, “but for much of New Jersey, and for the Philadelphia Metropolitan area, this is a big forecast miss.”
Szatkowski’s sincerity drew cheers, jeers and even a few laughs.
By 4 a.m. Tuesday, parts of New Jersey and eastern Pennsylvania were downgraded to a winter weather advisory with only 3 to 5 inches of snow expected.
Szatkowski and his Philly team weren’t the only ones to miss their mark. Government forecasters in New York City — also relying on multiple forecasting models — didn’t fare much better. Accumulations there are predicted to be 10 to 14 inches, half of Monday’s forecast of 20 to 30 inches.
Meteorologist Eric Holthaus explains the model mayhem in Slate:
The reason for New York City’s low totals? The National Weather Service strongly weighted their forecast toward the historically more accurate European Center for Medium Range Weather Forecasting model (ECMWF) and the high resolution North American Model (NAM), which showed the Long Island snow band stalling out directly over the city. That didn’t happen. In constructing their forecast, the New York City office of the NWS all but ignored their own recently upgraded Global Forecast System (GFS) model, which showed significantly less snow in the city. As late as Monday evening, the NWS emphasized that the storm could over-perform in NYC, saying, “it should be a raging blizzard.”
After his apology, Szatkowski kept tweeting weather updates deep into the night.