Wednesday, March 7, 2018

Weird, Challenging Nor'easter Snowstorm Continues To Keep Forecasters On Toes

Extremely heavy snow falling in Bucks
County, Pennsylvania today. There were
widespread reports of thundersnow and
snowfall rates of at least two inches per hour
The long-promised nor'easter is now well underway in the Northeast, and it's continuing to frustrate the heck of out many meteorologists.

Early runs of computer models a few days before this storm were remarkably consistent in forecasting what this thing would do. Those same models have been all over the place - not knowing what to predict - as the storm got underway.

That's the opposite of how it usually works out. Forecasts usually get more accurate as we get closer to the storm. Not this time, really.

Broad brush: The latest trends suggest northwest Vermont will get a little less snow than we were thinking last night. As I say that, parts of New Jersey, southern New York and inland southern New England are getting blasted even more than many forecasters thought.

The bad news is this worst of the storm seems to be hitting New Jersey, the New York City metro area and on up into the lower Hudson Valley and Connecticut right at rush hour today.

Things weren't too bad earlier today in that neck of the woods, so a lot of people went to work. Now that it's time to go home, YIKES!

Snow late this afternoon is coming down at a rate of two to three inches per hour, which is amazing. Visibility sucks. And since temperatures are near 32, that wet snow compacts under car tires to create slick ice, then deep accumulations pile up on top of that. And throw in some lightning and thunder to make things really dramatic.

By the way, there's LOTS of thundersnow in New Jersey, southern New York and Connecticut. More than I've seen in a nor'easter in a long time.

Yeah, just try driving in that crap.

Additionally, this is very wet, heavy snow down there. A lot of trees and power lines are coming down.

Those bands of heavy snow are, as expected, moving north into northern New England, but the question is, how intense will the snow be tonight, given the latest computer guidance that the storm will go a little further east than earlier anticipated?

One band of snow moved northward through Vermont this morning and early afternoon, laying down a half inch ot an inch and a half of snow. But it's March, and when a weak sun temporarily struggled through the clouds, most of that melted.

The bigger band will come through tonight, so there's no snow to cause any melting

An initial band of snow with the current nor'easter dropped
0.7 inches of snow on my property in St. Albans, Vermont
late this morning and early this afternoon, but the
higher sun angle in March meant that a lot of it
melted when the sun struggled to come through the clouds
So the latest thought is that anything in Vermont east of a line from Middlebury to Newport can still expect at least six inches of snow by the end of the day Thursday. In the Champlain Valley, it may - or may not - end up being a little less than that.

It depends upon how the northward moving snow bands hold together.

The National Weather Service office in South Burlington, Vermont has a fairly doubtful outlook on this, so they've downgraded winter storm warnings in the Champlain Valley to winter weather advisories. 

They're saying four to six inches - total - in the Champlain Valley. They're probably right, but this storm has held so many surprises that I'm not counting on that forecast, even though we're right at the cusp of the storm starting, when we're supposed to know what's going on.

I guess just expect lousy travel conditions overnight and on Thursday morning as we deal with this snow.

It still looks like whatever snow we get will get lighter during the day Thursday, but it will continue off and on into Saturday. There will be light additional accumulations each day through Saturday up here in Vermont, but nothing spectacular.

In the warmer valleys, there will also probably be a small amount of melting as temperatures rise just above freezing, and the stronger solar radiation in March will get through the clouds.

Speaking of computer forecasting models not knowing what's next: Nobody has any idea what the frig the weather will be like early next week. I guess we'll have to wait to find out.


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