Snowy Vermont Spring Setback Looking More Likely; NW, Alaska Heat Partly To Blame

A first look at expected snowfall Thursday night through Saturday.
Yellow and orange areas would get more than six inches of snow.
This is a preliminary forecast and WILL change. 

As of early Wednesday morning, things still looked like they were coming together for a snowy slap in the face, especially Friday night and into Saturday for Vermont and surrounding areas.

Oh, joy!  

Astronomical spring starts today and it will be deceptively benign, with highs in the 40s under quite a bit of sunshine, so not bad!

It's still looking like that nor'easter will get going after all, and with it, we'll get a big slug of precipitation. At least some of it will be snow.

Weather will deteriorate somewhat tomorrow, with clouds and a rising chance of rain showers in the afternoon.  Everybody except the highest mountain peaks should stay rain.

Thursday night and Friday, the main body of precipitation comes. Had this been mid-winter, everybody in Vermont would have gotten solid six to 12 inches of new snow out of this, with some places getting more.

But it's getting toward the end of March, and it's warmer. At least in the valleys, at least some rain looks likely. But this is tricky. A degree or two will make all the difference. Right now, the National Weather Service in South Burlington is going for mostly rain in the valleys Thursday night and Friday.

If that's true, valley dwellers won't see an enormous snowstorm, but could get several inches toward the end. More on that in a bit. If it turns out to be a few degrees colder than forecast, we could have a winter wonderland on our hands.

Early forecasts, which are totally subject to change, snow a most likely storm total of perhaps three inches in the Champlain Valley. A worst case scenario (with just a one in ten chance of this happening) would dump 10 inches of new snow on the Champlain Valley with even more in the mountains.)

All together now, Oh, Joy!

In the mountains, there will be more snow. It's hard to say at what elevation the rain/snow line will be. The very highest elevations will get a lot of snow. I have no idea yet about those of you who are not really in the valleys, but not really up at the tippy top of mountains either, stay tuned.

Colder air works in Friday night as the storm begins to depart, but the set up right now looks great for upslope snows.

That's when a departing storm wraps moisture in from the north and west, and strong winds go up and over the mountains. The western slopes and mountain peaks will get blasted with this. There's a good chance storm totals in some of the northern Green Mountains will go over a foot.

This is great news for late season skiers, but bad news for people worried about spring flooding. This storm will add to an already substantial snowpack up in the mountains. And this storm will further delay the spring melt.

Valleys, including the Champlain Valley, will share in this upslope snow Friday night and Saturday, too. There's the potential for several inches of snow, especially north of Burlington and away from the immediate lake shore.

After a brief warmup Sunday when temperatures are forecast to get up into the 40s, another cold front will give us more light snow, and more winter chill for the first half of next week.

Let's say it again: Oh, Joy!

By the way, this storm will bring heavy rain and strong winds to southern New England. It will be a little warmer in northern Maine than here during the bulk of the storm, so there is some risk of flooding up there.

NORTHWEST HEAT

A ridiculously resilient ridge of high pressure aloft has kept Alaska oddly warm all winter, and that is continuing now.

This ridge has been causing all sorts of havoc in the Lower 48 and is continuing to do so. Or at least contribute to it.

This ridge has fudged with the weather pattern for weeks. It's caused the jet stream to dive south into the northern Rockies and Plains, causing one of the coldest and Februaries on record in the northern half of the Plains and western Great Lakes.

That helped set the stage for the immense storm last week that unleashed a brutal blizzard on the high Plains, and more importantly the heavy rains last week that caused that huge flood in the central United States.

The ridge in Alaska was also one ingredient that caused the general storminess over the winter, especially late in the season, over much of the continental U.S.

That hot ridge in Alaska has sort of rejiggered itself a bit in recent days. Earlier in the winter, it fed cold air down into coastal British Columbia and Washington State, causing a lot of snow and cold weather in February, which was unusual in a normally mild climate.

This week, the ridge extended into those very same areas causing record warmth.

All-time record highs for the month of March have been set this week from Alaska to Washington. Here we go again with these bizarre extreme warm spells that have become so much more common than decades ago. (I can't prove the record highs I'm about to list are direct caused by climate change, but they are certainly consistent with what you'd expect from global warming.)

Sitka, Alaska reached 67 degrees Tuesday for a new March record high and the warmest temperature for any date between October 7 and April 16.  Eagle, Alaska, set a record high for the month of March with 55 degrees and Northway also set a March record of 50. High temperatures in those two towns are normally in the mid-20s this time of year, says the National Weather Service in Fairbanks, Alaska.

Tofino, British Columbia set a March record high of 74 degrees. Amazingly, that would also be the hottest temperature on record for that town for the month of April.

Further south, Seattle reached 79 degrees on Tuesday, its hottest March day on record. More record highs are anticipated for Seattle and environs today.

This ridge in the west this week has created a corresponding dip in the jet stream over the eastern United States. This dip is one important reason why we in Vermont appear as if we're going to get another snowfall Friday and Saturday.

One more time: Oh, Joy!