First order of business is a very cold night tonight. Cloud cover today kept temperatures in the low 30's and gusty winds and flurries made it look and feel more like January. Clouds have already begun moving out from the west, and have introduced partly cloudy skies across the region. Radiational cooling will allow at least a 20 degree fall tonight, which will send us into the teens for sure with lows between 10 and 15. GFS MOS forecast is 13, ETA is 17, and GFSX is 14. NWS zone and point forecasts are going with 14. The record low for tomorrow is 14 set in 1982. So we do have a good shot at breaking the record tonight.
The second event on the list is a 1004mb low pressure system currently centered in North Carolina with associated showers about 100 miles to the west. This low will organize and move east over the next 12 hours and redevelop as a coastal low east of NC. The storm is expected to move northeast tomorrow and well south of New England on Sunday, and deliver a coating to 3 inches of snow across the Mid Atlantic region. This could make up a large portion of the seasonal total for some areas. The precipitation shield will deliver a glancing blow to Cape Cod and the islands, and could give them an inch or two. The biggest effect here will be mostly cloudy skies and gusty winds. We should give this storm a little bit of attention, in case a shift north does occur (the result being a chance of snow showers on Sunday).
Behind this storm, a shot of uplevel cold will flow in, with the 850mb -10C line forecasted to drop south into the Great Lakes region. However, a southeast ridge will begin to build at the surface in response to a significant jump into the positives for the AO, which will support high temperatures up into the 40's through Wednesday. In this case, we will be talking about elevation temp gradiants in the area of about a degree every 100ft. High pressure will keep the air dry and the skies clear through this period as well.
The main weather story of next week is the storm potential on Thursday. The GFS has been consistent for the past 5 days(!) in showing a strong coastal storm affecting the eastern third of the nation. The Euro has jumped on as well. All the runs in the past 3 days have shown a low at least sub 1000mb. The 18z GFS (latest) actually bombs the low below 980mb! The GFS brings a slug of moisture north into the region with widespread 2+" QPF and even up to 4" in parts of NY state.
The track of this low will be extremely important in determining whether we get a record breaking late season snow storm or some April showers (heavy "showers" more likely). There will be a good amount of cold air aloft, so even highs in the mid 40's could support a rain/snow mix. If the low track shifts eastward, we could see significant amounts of snow at the end of next week. This storm will be similar to the March 16-17 storm which dumped a foot of snow and sleet in Keene with greater amounts to the west. Besides the track, srength, and precipitation type, the March storm occurred during a +AO and +NAO regime, in which this latest storm is forecasted to occur. Based on the strength consensus among the models so far, I am confident in at least a moderate snow event for the ski resorts up north. It looks like the ski season will be hanging on pretty late!
Behind this storm, the ensemble forecasts have a decent agreement on the AO and NAO forecasts for the 14th through the 18th of a steady drop back into the negatives. I am fairly confident on below normal temperatures continuing through the 20th during which we may receive one last snow event. After the 25th, confidence is high on the arrival of Spring.
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