NAM: Generally about 20-40 miles further south and west than it was this morning. This also shifts the rain/snow line further west as well, through Albany. This also shifts some of the snow a little further south as well. The morning run spit out about 0.75" liquid in the form of snow in Philly. This evening run spits out over 1" liquid. Warm air intrusion cuts down on snow amounts in Central New York and Eastern New York (massive shadowing is being picked up in the Hudson Valley now). The Catskills are the big winners. This also cuts down considerably on snow in Connecticut and NYC. There is an incredibly sharp rain/snow line evident around NYC, with literally the difference between double digit snow and rain, around 10 miles. The NAM also brings heavier snow into NJ now too.
GFS: On the other hand, the GFS has now shifted a bit further east and north. This morning's run had the low centered over Warren County, NJ on Thursday evening. Tonight's run has it centered around Newburgh, NY, or about 50-60 miles further north. This really confuses the issue with the rain/snow line punching through Albany again.
So with that said, here's a risk map, basically outlining the situation...as it stands right now. This can and probably will change:
There is still a ton of uncertainty. Some of biggest questions:- How far south will enough cold air and heavy precipitation go to bring heavy snow. Is that line in Philly? South of Philly, north of I-195? I think at least 6" is likely in Philly and most of Central NJ.
- South NJ will be dependent on this as well. I would say at least 3-6" likely there, but higher amounts are very possible.
- NYC will be another story as well. The low tracks VERY close to New York, so that will limit how much cold air can get in. There's going to be a tremendously sharp cutoff between heavy snow and heavy rain.
- Latest model prognostications are showing that incredibly strong easterly winds aloft will transport marine air clear across the Hudson Valley and into Central New York, probably to Syracuse. This will likely change them over to a mix of rain and snow or even just rain/drizzle for a time.
- A wicked "dry slot," or pocket of dry air is going to surge into this storm as well and will limit snow totals.
- That warm air may limit how much snow falls in the Berkshires or Green Mountains too.
Historical Comparisons
I have what can be considered the Bible of Northeast Snowstorms, by Paul Kocin and Louis Uccellini. It has a number of archived cases of past storms. I went back and came across five somewhat similar storms in some aspects:
Feb 14-17 1958
Dec 25-28, 1969
Feb 18-20, 1972
Jan 21-23, 1987
Apr 18-19, 1983
I won't bore you with the details, but...in all of these cases, MAJOR snows fell on the Catskills, far Northwest NJ and parts of the Poconos. In some instances, this was 20-40" of snow. There is precedence for a massive amount of snow in a few spots in those locations, coupled with strong winds, and you have the makings of a crippling blizzard in the mountains of Northeast PA and Southern NY...and possibly the Eastern Adirondacks.
Much more on all this tomorrow.
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