Another Signifcant Winter Storm on tap for parts of New York, New England...

First and likely final snow accumulations map covering the synoptic event combined with potential lake effect where applicable. This timeframe covers thru Monday Evening when the bulk of the action should finally be winding down, both with the synoptic event and expected Lake Effect event on the backside.

We could potentially see an expansion of 2-5" across the NY/PA/NJ corridor depending on how far south the secondary develops from what the model guidance shows. As of now, best chance for 2-4" will be along/east of I-81 and north of I-80 in Northeast PA northward into Central NY.

Across Northeastern New York and the northern half of New England, this is where the bulk of the snow is expected to fall. Current thinking is that most areas should stay at or under 20" from the synoptic event. That said, expectation is that there will be significant upsloping/terrain-induced snowfall following the end of the synoptic snowfall across the mountains/hills of Northeastern VT, Northern NH, and Western/Northern Maine that will carry on during much of the day on Monday. When all is said and done, this will result in total snowfall amounts reaching or exceeding 24" in localized areas. This is represented by the hollow dashed maroon zone of 20-30" which signifies an area where upwards of 20" is possible, but only localized and not widespread enough to fill in.

Concerning lake effect potential do, we have inserted a swath of 5-10" downwind of Lake Ontario with a localized highlight over parts of Oswego/Oneida/Madison/Onondaga counties where amounts could exceed 10". This is signified by a dashed hollow purple zone corresponding to the purple range of 10-20" seen in the legend. Again, dashed and unfilled signifies local amounts expected within that range, but not expected to be widespread enough to fill in.

...LTE

Significant Winter Storm Expected Across Parts of NY and New England

For the most part, this will just be a nuisance type storm with snow changing to rain. Most will only see a Trace to perhaps as much as 3" across the higher terrain. Across parts of Upstate NY into Northern New England, this event will produce a moderate to locally heavy snowfall, with highest amounts across the mountains. We have capped the snowfall at a maximum of 10", which will be possible across Adirondacks of New York, Green/White mountains of Vermont, and the Foothills of Northern New Hampshire and Maine.

We have highlighted several areas where locally heavier amounts are possible. Most of this area is in responses to the expected wrap-around and Lake Effect/Enhancement from Lakes Erie and Ontario on the backside of that Low Pressure. The region across North Central PA and the Northern Pocono mountains are where local amounts of up to 3" could be found from the intial wave of snow. Elsewhere, downwind of Lakes Erie and Ontario could potentially see some moderate to locally heavy amounts of snow, particularly the mountains of Northwestern Pennsylvania and the Chatauqua Ridge of Western New York. Concerning Lake Ontario... expect Oswego, Oneida, Lewis, and southern Jefferson counties will be under the gun for this event, with locally in excess of 1 foot possible.

We do expect a Lake Effect Event to setup during the day late Thursday into most of Friday, however this forecast package extends only thru Midnight Friday. Therefore, the projected accumulations are only meant to capture the early going enhancement before any significant Lake Effect Plumes set in.

LTE

Yet Another Messy Storm for the Northeast

While we are definitely not ruling out the possibilty of some icing in certain areas we think that it will be relatively minor. The atmospheric temps are going to support more of a snow vs rain scenario. With marginal surface temps and the warming aloft, I'm thinking rain and 33-35F is in the cards for many people after some initial snows.

For the transition zone we finally settled on just calling it snow/rain rather than snow to rain. It makes the map a bit more universal and general, a lot of folks are going to mix with and/or change to rain, and some are going to go back to snow. So instead of highlighting about 15 different scenarios, we kept it simple.

...MAG