Thursday, December 17, 2009

Models Not In Agreement for Saturday Night/Sunday in NYC Area...

The models are still diverging on a solution for the potential coastal storm that could dump up to 6 to 8 inches of snow (NAM model, 1st map from the top) or it could just graze the area with an inch or less Saturday night and Sunday morning as per the GFS solution (2nd map from the top). As what has been common over the last few seasons, the models forecast a coastal storm that develops over the Southeast to track too far to the NYC area to produce significant snow several days before the event but then as the event approaches, the subsequent runs produce a storm that is closer to the coast and the precipitation shield is farther inland producing a significant winter storm for the Tri-State New York area. This may happen if the 500 mb or upper-level jetstream phases in to produce a stronger and deeper trough as the NAM is forecasting (3rd map from the top). The GFS is forecasting a broader trough that does not intensify and does not "cutoff" at 500 mb thereby producing a more progressive pattern and a weaker and faster moving storm (4th map). Right now, I feel that the NAM solution is more likely with a light to moderate snowfall for NYC, NJ, CT and LI for Saturday night and Sunday. More updates on this tomorrow.

George Wright is a Certified Consulting Meteorologist and President of Wright Weather Consulting, Inc. Our web site is WrightWeather.com.