Very Strange Wintry Blast Still On Its Way

That purple bullseye over the Northeast is that chunk of
the polar vortex that broke off. .It will bring an exceedingly
cold Mother's Day weekend to us. 

The long anticipated, strange wintry blast still hasn't officially hit the Northeast and Great Lakes yet, but we here in Vermont and the rest of the North Country have already gotten a foretaste of it.

A dusting of snow on the ground greeted some people in the Northeast Kingdom when they awoke Tuesday morning.

It stayed chilly all day, too, especially up in the Kingdom. I noticed Lyndonville was only 39 degrees at 3 p.m. Tuesday.  It was down to 19 degrees (brrr!) in Saranac Lake, New York this morning.  

It will warm up, kinda, sorta, today and Thursday, but temperatures will still be below normal. Daytime highs both days will be in the 50s, with maybe a spot 60 degree reading here and there. That's still a few degrees on the chilly side for this time of year.

But that weird, big cold snap is lurking on our doorstep. By Saturday, it will seem like early March, not early May out there.

In the winter, the now infamous polar vortex spins up in the Arctic. Pieces of it occasionally break off, plunge southward and cause intense, subzero cold waves.  That didn't really happen in our neck of the woods this past winter.

By May, the polar vortex up there in the Arctic is very much weakened by the strong spring sun.  If a piece of it manages to break off, that cold chunk usually gets swiftly shunted eastward across Canada and out into the Atlantic.

Here in northern New England, when that happens, we get a bit of a cool snap and maybe a little frost in some spots.

This time, this will be a classic winter polar vortex thing.  A sizeable chunk of it has broken off and is plunging southward through eastern Canada and will crash into the Great Lakes and New England, just like the worst ones do in, say, January.

I'm not sure anyone has ever seen anything like this in May.  It could have happened in the past, but it's incredibly rare.

The upshot is a real return to winter on Mother's Day weekend.  Of course, temperatures won't go below zero like in a winter during a brush with a chunk of the polar vortex.  But it will be incredibly, weirdly cold for May.  With some snow to add to the misery.

You'll really start to notice in Friday as temperatures stay in the 40s and a few rain and snow showers filter down.

Saturday is when it really hits.  That chunk of frigid air will spin up a storm off the East Coast.  Luckily, it will be far enough offshore, as it looks now, to mostly avoid giving us a lot of precipitation. That's a good thing in this case, because the air would be cold enough to support a big late season snowstorm.  Kind of like a frigid January nor'easter.

Some forecast models bring the storm closer, but for now, we'll say it's a miss.

So, we will probably avoid a full-fledged snowstorm, but we'll still get snow. The storm will blow up into a powerful one as it heads toward the Canadian Maritimes.  That means a lot of wind for us in the form of cold, northwest gusts exceeding 30 mph at times. Moisture will wrap around that storm and come down over New England.

That moisture will spit out frequent snow and rain showers here in Vermont later Friday night, Saturday and into Saturday night.  Really, it will be mostly snow showers, believe it or not, except maybe in the warmest valleys.

Warm is a relative term for this weekend, that's for sure.  On Saturday, when normal high temperatures this time of year are in the low 60s, it will barely get above freezing up in the Northeast Kingdom.  In the Champlain Valley banana belt, it would actually get above 40 degrees for a brief time Saturday afternoon.

That's pretty incredible and rare for this time of year.  Since precipitation will be light, snowfall accumulations also won't amount to much. Still, I can't believe I just wrote that sentence with a straight face in May.

Higher and middle elevations could get an inch or two out of this, and there might even be a little coating in the valleys.

Wind and clouds will keep temperatures from really crashing Friday and Saturday nights.  It will get down to between 30 and 35 degrees both nights, which is not really cold enough to kill all the ew leaves on the trees.

We will have to watch for the risk of plant killing cold nights early next week.  Temperatures will "warm" into the 40s Sunday afternoon, which is still 20 degrees colder than normal. Highs will only be in the upper 40s Monday and Tuesday. If skies clear and winds die down on any nights Sunday through Wednesday we could get leaf-shriveling lows in the upper teens and 20s,

That remains to be seen.  We'll have to wait for updated forecasts.

The cold spell isn't just affecting us, obviously. Damaging frosts are a risk with this thing as far south as Tennessee and the Carolinas.

If you want a glimmer of hope through this cold spell, it does look like temperatures will start to climb to near normal levels toward the end of next week.