Will We Have a White Christmas?

There's an increasing possibility of a white Christmas this year; especially for areas along the coast east of New York City. While most of us love snow on Christmas, the potential impact of this storm could be disruptive.

It is quite difficult to forecast winter storms; especially the variety we tend to get here on Long Island. We rely on computer models that use an enormous amount of observable data to try and best predict how a weather system will play out. In the U.S., there are two main models that meteorologists look to for guidance: the Global Forecast System (GFS) and the European Centre for Medium-Range Weather Forecasts (ECMWF).

The GFS is an American computer weather model while the ECMWF is European. These are the two most reliable long range computer models and are especially important when trying to forecast east coast winter storms.

Currently, both of these models indicate a potent storm on Christmas day. As modeled, it would be a classic Nor'easter, with a low pressure system strengthening off the coast of Deleware as it heads Northeast. It is impossible to pinpoint the exact strength and track of a storm this far out, but there is model agreement on a storm in this timeframe. This storm is then expected to interact with the northern jet stream and the timing of this will be key to the eventual development and track of the storm.

The models that bring the storm in quickest call for it to impact the Port Jefferson area Christmas evening, while the slower forecasts don't call for any impact until the day after.  However, most forecasts indicate a higher probability of a storm impacting the area from Dec. 25 through Dec. 27.

Greg Oddo, meteorologist for Metro Weather Service, says this type of scenario tends to focus the worst of the storm along the coast.

"I would tend to favor eastern areas for the most significant impact," he said.

He continues to offer his opinion on the upcoming storm, saying, "There is a valid threat for significant snowfall for Long Island."

Local weather message boards are already abuzz with the prospect of a snowstorm.

The American Weather Forums is the busiest weather message board in the U.S. and features a sub-forum for the local Long Island area. The current discussion thread for this particular storm already has over 900 replies and 40,000 views.

John Homenuk, a junior meteorology student at Kean University and moderator of the local forum is on board with the storm threat.

"I think the potential definitely exists for the storm to impact the area," he said. "The current modeling signals are strong for the development of a storm off the coast."

The forecast will become clearer as the event approaches. Historically, the probability of a white Christmas on Long Island is under 20 percent, but right now it looks like we may face at least some snow in the days around the holiday.