Are nor'easters hard to forecast?

Dateline article| David Murphy|

by David Murphy

Nor'easters can be tricky to forecast.

Normally, computer models project the formation of a future nor'easter days before it actually happens---and sometimes, they get it wrong. The strength and position of the developing low-pressure center is everything, when it comes to whether this type of system is going to be a problem for us. If it tracks a bit west, over land, the storm will bring mainly rain and lighter snow because it's drawing less moisture from the ocean and pushing the colder air needed for snow farther west. On the other hand, if the storm center tracks farther out to sea, it will bring only a little snow, or nothing at all, because the strongest portion of the storm is too far away. In some cases, the storm center follows a path close to the coast, but doesn't intensify quickly enough to give us much snow. In these instances, New York City and Boston usually get hammered, while we see very little accumulation.

Tracking an approaching nor'easter always requires repeated analysis and the ability to recognize changes in both the track and intensity of the storm. To tell you the truth, this is one case where having Storm Tracker 6 HD and 3-D, really pays off. It's also not exactly a bad thing to have a partner like AccuWeather during nor'easter season, with their around-the-clock analysis by dozens of veteran meteorologists.

Because nor'easters are so potentially threatening, we treat these storms with a lot of caution and usually warn for snow as many as four or five days in advance of the storm's arrival. But we also realize we can't always be certain of whether it will be a major snowstorm until the storm actually forms and begins to move north. Even then, there are variables to consider. At Action News, we've committed to a responsible approach in forecasting these potentially dangerous storms which often includes multiple forecast scenarios, days in advance. We also feel it's important to maintain composure as these storms draw near, careful not to overblow their potential affects until we have the information we need to make an educated, sensible call. At the same time, like a hurricane that may still be days away, we feel strongly about informing viewers of potential snow as much as five days in advance to allow for necessary preparations.

The bottom line? You'll always know days in advance of the potential for one of these storms---often, you'll hear it here first---but we'll also be responsible, usually holding off on specific snowfall predictions until we're within about 48-hours of the storm's arrival, since earlier projections are so subjective, they're largely impractical in often inaccurate.

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