Jan 14, 2013 Noon Update

Update On Wednesday Rain/Snow Storm

Last night's update mentioned that the model guidance has trended north with the Wednesday event, and only a minor change in the track makes the difference between a dry, snowy or rainy outcome. Today's models continued this north trend, to the point where most show the area in the rain/snow boundary area. Currently, most models are in the colder side of this boundary, with at least 2 to 4 inches of snow in northern NJ and especially over SE NY and southern Connecticut. The GFS is the warmest model, with mostly rain for the area and a widespread snowstorm towards interior southern-central New England.

The main question at this time regarding the model guidance is if the north trend has stopped or whether the models are still in the process of adjusting north, considering that just yesterday afternoon most of the models still had the storm staying almost entirely south of the area. If the storm was to end up near the current model consensus, widespread light accumulating snow would be expected west and north of NYC, with some snow in NYC and Long Island as well. This would lead to something close to the first scenario shown below:

Meanwhile, the GFS, UKMET and SREF models are siding with the more northern outcome, in which the low pressure is stronger and more to the north. This solution would support rain for most of the area with snow for northern locations, also mixing with sleet/rain at some point, with the rest of the Northeast observing a moderate snowstorm, as was the case with the two most recent snowstorms, on December 26 and 29. This would lead to a solution close to the second scenario shown below:

There is still uncertainty with exactly which solution verifies. The model spread remains large considering this is only 42-48 hours away; using Albany, NY for perspective, the NAM model keeps snow south of Albany, while the GFS is far north/warm enough to show rain mixing with snow in Albany, with the heaviest snow north of there. The model guidance has not settled on a single solution yet, and will continue to change around over the next day. A more detailed forecast will be posted tonight and tomorrow; at this time, while the latest 18z GFS run may have been a bit too far north/warm with showing rain for almost the entire area, the rest of the models may be too cold/far south as well, and at this time I am siding with a moderately north solution closer to the 12z GFS. There is still some uncertainty, however, and should a slightly more southern scenario verify, a more wintry outlook would unfold for the area.

For more localized forecasts, please refer to the 5-Day Forecast, which is currently being updated. Stay tuned for more information with tonight's update.