Winter Storm Warnings & Advisories Posted. Arctic Air Looms..

Winter Storm Warnings and Advisories have been posted for a HUGE chunk of real estate stretching from the Appalachian Mountains of Northern Georgia straigh up through the Mid-Atlantic, New England and the rest of the Northeast.

The snow has been coming down steadily since last night for the Big Cities on the East Coast with already as much as 18-19 inches has been reported so far in Morris County New Jersey, a short distance west of New York City and also in Berks County Pennsylvania north of Philadelphia where the very heavy snow looks to gradually diminish overnight.

However, a secondary band of snow looks to develop over parts of Upstate New York overnight and into your Tuesday with additional heavy accumulations expected across parts of Central and into West-Central New York including the Finger Lakes region where Winter Storm Warnings have been posted including Albany, Syracuse and Binghamton.

Further west, Winter Weather Advisories go into effect in the morning for Rochester, Oswego and Dansville as snowfall is expected to ramp up with lake enhancement coming downwind of Lake Ontario.

Here's a look at the 3k NAM futurecast showing the snow "backing" into West-Central New York late tonight and continuing through Tuesday night before coming to an end early Wednesday.

So how much snow can be expected?

The Euro continues to show a generous amount of precipitation over the Finger Lakes Region with somewhere between a half inch to around three-quarters of an inch of liquid equivalent through midday Wednesday. This is something that is supported by the other major models as well.

Using a straight 10 to 1 ratio, it would appear that 5 inches may be the minimum amount for areas like Rochester. However, considering the thermal profile of the atmosphere which is good and cold, it should produce snow at a higher ratio than that. For reference, the Euro using the "Kuchera" method for snowfall prediction are throwing out some rather large numbers on the order of 10 to 14 inches for the region.

So what do I think?

As previously discussed on our live streams, this is not a typical set up. The slow moving nature of the evolving coastal low will put much of Central/Northern New York State in a favorable area of upper level lift and likely a prolonged period of accumulating snowfall on the order of 24 to 30 hours or so. Add to that the impacts from the relatively warm waters of Lake Ontario and I think we are looking at a some decent lake enhancement that should help to boost totals for those that remain in the most persistent bands. So while I'm not buying the above Euro Kuchera totals just yet, I do believe that parts of the Finger Lakes will likely see in excess of a foot of snow locally. For Rochester, maybe more along the lines of 4 to 8 with a sharp cutoff further west into the the Buffalo area where only a few inches can be expected.

Arctic Air Looms

Looking further out there is more and more evidence of a true shot of arctic air arriving next weekened. This would be the coldest air mass not just of the season, but perhaps the last couple of seasons with data suggesting actual air temps could fall below zero.