Tuesday Update: Today And Tonight's Winter Storm About To Strike

Tuesday morning's National Weather Service forecast map. Darker orange areas
get the most snow, around a foot, if this map comes to pass
Blue and yellow areas get the least snow and sleet, around 5-6 inches.

As of mid-morning Tuesday, clouds were lowering, thickening and turning darker as the well-anticipated winter storm is now on our doorstep.

The forecast hasn't changed too much since last evening's updates, but there's still a high bust potential in the predictions.

THE DETAILS:

The front part of the storm is pretty certain. Snow will spread from southwest to northeast across Vermont between 1 and 5 p.m today. When the snow hits, it'll go from just flurries to fairly heavy snow quite quickly, at most within an hour or two.

So, if you see flurries start in your location and think you'll leave work at that point to beat the heavier snow and the slick roads home, it won't work, unless you live less than five minutes from where you live. Snowfall rates in this first initial heavy band will probably be one to two inches per hour, with locally higher amounts.

That's pretty impressive, and is close to the heaviest snow rates possible in this neck of the woods. The National Weather Service in Albany suggests there's a slim but real possibility of thunder snow with this initial band as far north as far southern Vermont. We'll see.

Don't let the chilly temperatures this morning fool you. There will be plenty of warm air aloft for this, so mixed precipitation definitely enters the picture. And temperatures will slowly and steadily rise now through Wednesday morning, from the single numbers this morning to low 30s by Wednesday morning.

Forecasters are also sure that sleet will follow the snow this evening from southwest to northeast across at least a portion of Vermont. That's where the bust potential in the forecast comes in.

The last bit of sun glow in the southeastern sky over St. Albans,
Vermont this morning as the next winter storm approaches.
Look for plenty of snow and sleet starting this afternoon. 

As we said yesterday, the main storm is going by to our west, while another storm forms along the Northeast U.S. coast.

When that coastal storm gets going, it'll cut the northward progress of the sleet off at the pass. But where will that be?

Where the northward advance of the sleet stops depends entirely on how fast and how strongly the coastal low develops. If forecasters are off by just a tiny bit, the current forecasts will be wrong. How wrong at this point is anybody's guess.

At this point, the National Weather Service in South Burlington is thinking the sleet tonight will get as far north as the central Adirondacks and very roughly up to Route 2 in Vermont. North of that, the thinking is precipitation through the whole storm will be almost exclusively snow, with just the chance of a few brief ice pellets thrown in overnight.

Of course, when and where the sleet comes in depends on much accumulation we'll get.  In places where little or no sleet falls, the snow accumulation will obviously be the most. Those places look like it will be about a foot by Wednesday.

Here's where that is most likely: The thinking remains the big winners in the snow department for New York will be the St. Lawrence Valley and  a few places in the Adirondacks.

In Vermont, the deepest accumulations will be way up in northwestern Vermont in places like North Hero, Alburgh, St. Albans and Highgate. That's the third time this winter a big storm dumped the most snow in these locations. More often than not, far northwestern Vermont misses out on the biggest snow accumulations.

The far northern Green Mountains also look like they will be snow winners.

Southern Vermont is at risk for freezing rain with this, too.  I would say freezing rain could get as far north as Route 4, but again, this could be off by a fair amount. Far southern Vermont could get enough freezing rain to ice up trees enough to break a few branches and power lines.

Strong winds are still expected to be a factor along the western slopes of the Green Mountains, especially in central and southern Vermont. Winds there could gust to or over 50 mph. That also could bring down a few trees and power lines, especially in areas that get freezing rain.

As noted yesterday, the strong downslope winds on the western slopes will cut down on precipitation.  Between the sleet and the drying effects of those winds, parts of Rutland and Addison counties, for instance, might only get four or five inches of snow and sleet. Even that might be generous.

The Connecticut River Valley from White River Junction south look like they will get six inches of snow or sleet - or less out of this.

As the coastal low takes charge tomorrow morning, mixe precipitation will go back to snow, then taper off across most of the area.

The bottom line is this afternoon's commute, and the one Wednesday morning will be tricky regionwide.

Across northern and central Vermont, the snow looks like it might pick up in intensity again for a time Wednesday afternoon and evening, which would prolong the risk of slippery roads in the region.

ELSEWHERE

This storm is creating a mess from the Midwest to Maine.  Lots of places have already gotten a ton of freezing rain and sleet, and that trend will continue the rest of today. ]

For the second time this month, Chicago was under an ice storm warning early this morning. Roads are a mess out there, with trees and power lines weighted down by a lot of ice. It's going to turn windy later today in Chicago, meaning, more icy trees and branches might come down.

Southern Michigan is experiencing the same problem as Chicago this morning. A lot of freezing rain with its associated damage is likely tonight in places like Pennsylvania, New Jersey, southern New York and parts of southern New England.

Further south, the rain is coming down in torrents. Flood watches and warnings extend from Tennessee to the southwestern corner of Pennsylvania.

It's been a particularly stormy winter nationwide, from Hawaii to Maine, and this is the latest assault. An active weather pattern is likely to continue through the end of the month, but of course, it's hard to tease out more than a few days in advance the particulars of how each storm will behave.