Weird Post-Christmas Winter Hot Spell To Embrace Most Of North America. But It Might Not Last Long

Forecast map via Tropical Tidbits showing most
of North America with temperatures above normal
roughly a week from now.  The map shows
how far temperatures would be above or
below normal for this time of year. They'd
be farthest above normal near Hudson Bay,
but since it's winter, those "warm" temperatures
would only be in the 20s and 30s.

 We're heading into the depths of winter in North America, but you wouldn't know it given the Christmas Week forecast for almost the whole continent.  

Normally, large sections of the vast land mass would be colder than average for the season while other big areas would be having mild spells. 

By mid to late week, the only areas that will be chiller than usual for the end of December are Alaska and a small adjacent piece of northwest Canada.  Western Mexico might also be on the cool side, but not by much. 

Virtually all of Canada, from the British Columbian coast to Labrador, and from the southern tip of Ontario all the way north to Nunavut in the Arctic will be warmer than average.

Same is true coast to coast in the Continental U.S., except for maybe a small spot in California's Central Valley.

Now, it's winter, so nobody will be exactly hot. A few record highs are possible during this weird spell, especially in areas of Canada roughly near Hudson Bay, and then down toward the Great Lakes. 

For instance, in northwestern Quebec, near the shores of Hudson Bay, normal highs this time of year and in the teens to near 20 below Fahrenheit.  By the end of the week, those places will be in the mid 20s to low 30s above zero Fahrenheit, which is impressively balmy for this time of year. 

I'll want to oversimplify this, but is a forecast
showing the overall air flow in North America
in the last days of December. Follow the green
lines, You seen they come off the Pacific'then curl
north into eastern Canada. That blocks any cold
air in far north from coning toward the U.S. Red
hatched lines in Canada depict an upper air 
pattern that strongly favors warmer 
than average temperatures.

But the impressive thing is how huge this area of above normal temperatures will be, especially for this time of year.

The reason for this is a massive flow of mild Pacific air flowing into North America from the west.  Additionally, there's a massive northward bulge in the jet stream beginning to form. It's centered in central and eastern Canada, and by the end of the week will be enormous. 

That warm Pacific Ocean air will be forced to move both eastward across the United States, and northward through central and eventually into northeastern Canada - way the hell up there. 

This arrangement is pushing the usual pools of frigid air far to the northwest, centering it north of Alaska. Plus, this cold pool looks like it's smaller in size and weaker than you'd usually see in the winter. 

Usually, this cold pool is much stronger, and often extends across much of the northern half of Canada, and often centers itself near or not far from Hudson Bay. When that happens, the usual, occasional bursts of Arctic air can easily flow into southern Canada and the eastern two thirds of the United States.

As long as this weird weather pattern holds in place, there will be no more cold air to be had in eastern North America for awhile, at least after a zone of frigid air over southern Quebec and the northeastern U.S. gets out of here within a few days.

Don't expect this balmy North American winter to last forever. In fact it probably won't last all that long.  

It appears one of the more likely scenarios is that the big northward bulge in the jet stream over Canada might split in two, with one northward bump to the east, and the other in western Canada. That would create a southward dip in the jet stream between the two. That southward dip would allow cold Arctic air to eventually spill into south-central Canada and at least parts of the United States. 

If I had to guess, this would start happening a few day into the New Year.  NOAA's three to four week outlook, issued Friday and covering the period January 4 to 17, pretty strongly predicts below normal temperatures for most of the eastern two thirds of the United States.  The cooling trend in New England might (or might not!) wait until a couple or few days after January 4.

 

New Snow Might Keep Us Refrigerated All Week, Even After Intense Weekend Cold Departs

Steam and warmth from Lake Champlain was still
creation clouds over the lake near Burlington this
morning, as this hazecam.net screen grab shows,
but the lake effect snows of yesterday are over. 

Yes, yes, I know, it's nasty cold out there in Vermont and surrounding areas. 

Jackson the Weather dog here in St. Albans really cut short his early morning observations when we went out before dawn today.

  He's not into this type of chill at all. Can't say I blame the little guy. 

Low temperatures this morning were pretty uniform statewide in Vermont this morning.  That tends to happen when there's a steady winds. 

 Burlington was the banana belt town as usual, dipping down to 5 degrees this morning.  Everyone else was pretty much between 5 below and 2 above, even in the valleys of far southern Vermont. 

Wind chills this morning were mostly in the teens below zero.  You'll really want to dress for the weather today, as most of us won't even make it to 10 above, and the north wind will continue to blow steadily. Don't be fooled by the sun when it comes out. The low angle light won't help with the chill at all. 

Yesterday's lake effect snows in the Champlain Valley might well contribute to the end of Burlington's longest continuous stretch of above zero temperatures. Today was the 663rd day in a row that was above zero, as measured at the National Weather Service office in South Burlington. 

Usually, the Champlain Valley receives the least snow in any given winter storm. This time, they got the most, thanks to that lake effect snow Saturday. 

Six inches of snow covered Shelburne, Vermont. In a rare feat, The National Weather Service office in South Burlington was the snowfall winner, with a storm total of 6.3 inches.  

Because the snow cover around Burlington is deeper than what had been forecast, that improves the chances that the record long stretch of temperatures continuously above zero will end.

Deeper snow tends to encourage lower temperatures on clear, calm winter nights. Monday morning could well end the long, long streak of continuously above zero temperatures. 

But it's not a slam dunk.  If any clouds move in off Lake Champlain, or the wind stirs a bit at just the right time, it'll stay above zero in Burlington. The current forecast for Monday morning's low is 1 above. But it honestly could end up at up to five degrees either side of that figure. 

If you're away from the lake, it's pretty much guaranteed you'll be below zero early tomorrow morning.  temperatures will vary early Monday much more than they did this morning. The cold hollows could make it into the mid and upper teens below zero.

CHILLIER OUTLOOK

It's not going to warm up as much or as fast during the upcoming week as originally thought. A quick Alberta Clipper will probably sneak through real quick Monday night and Tuesday, throwing a couple more inches of snow our way. 

Meanwhile, the high pressure that's bringing our weekend nasty chill will park itself over southeastern Quebec much of the week. The air mass will modify, so that temperatures will become seasonable and comfortable - highs in the 20s to low 30s.

But since there won't be much in the way of south winds, and the snow cover will help chill the air near the ground, there won't be any wholesale warmup at least until the end of the week. 

However, it could warm up a lot toward the New Year.  A strange weather pattern is setting up that will roast most of North America, relatively speaking, in oddly balmy air for winter. I'll get into that in an upcoming post. 

Why You'll Never Receive A Wind Chill Warning Ever Again

The National Weather Service has scrapped wind chill
advisories and instead will issue cold weather advisories
or cold weather warnings when dangerously low
temperatures are expected. The logic: It doesn't matter
if it's windy or not.  If it's really cold, it's really
cold regardless of whether the wind blows or not.

 No, this isn't about climate change. 

Despite a warming planet, we in New England and many other parts of the United States will continue to see bouts of dangerously cold weather during the winter. 

But the headline on this post is accurate. The National Weather Service will never again issue a wind chill advisory or a wind chill warning. 

Those warnings have been replaced by weather alerts that the National Weather Service and social scientists hope will be simpler and easier to understand and absorb. 

For the first time this season, one of these new weather alerts has been issued for our area.  There's what is now known as a cold weather advisory up for Adirondacks tonight and early Sunday. 

Cold weather advisories replace what used to be wind chill advisories. These advisories alert people that  it's going to be pretty cold and to bundle up, because of the risk of frostbite and hypothermia, but it won't get quite as bad as it can get in that location

What used to be a wind chill watch is now a cold weather watch, meaning the it's becoming likely it will get dangerous cold. The old wind chill warning is now a cold weather warning, which means it's dangerously frigid outside, and you're better off staying indoors. If you must go out during a cold weather warning, make sure no skin is exposed to the bitter air. 

The National Weather Service explains why the winter cold alerts are now different:

"These changes seek to clarify that cold can be dangerous with or without wind, addressing a common misconception that extreme cold is only tied to colder temperatures when there is wind. Dangerously cold weather can accompany or follow wintry precipitation and the cold messaging can be overshadowed by wintry precipitation."

If the cold spell in question is windy, the cold weather warning will definitely mention the wind chill risk in the text of the warning. But it will emphasize that cold is cold.  It really doesn't matter whether the actual temperature is 30 below, with no wind,  or if the actual temperature is 0, but blustery air brings the wind chill down to minus 30.

Either way, it's dangerous.  

These new warnings haven't gotten much of a workout here in Vermont yet.  After tonight's in the Adirodacks, there might be further cold weather advisories Sunday and Sunday night. But after that, a warming trend will preclude these new warnings.  

We'll have to get used to them in January, I guess. 

Vermont Lake Effect Snow Develops In Champlain Valley; Up to 6 Inches Snow Possible

National Weather Service radar this morning showed
two lake effect snow bands coming off of Lake 
Champlain. One was hitting an area in and around
Colchester and Milton, while another stronger one
was in southern Chittenden County and 
in Addison County. 

 As mentioned in a post earlier today, it's still snowing a little across Vermont. 

But in the Champlain Valley of Vermont, especially in Addison County and the southern half of Chittenden County, something of a lake effect snowstorm has blossomed this morning. A winter weather advisory has been issued or those two counties. 

Areas along the Route 7 corridor from near the shores of the lake to the western slopes of the Green Mountains in this area can expect a storm total of up to six inches of snow.

There was actually two  snow bands coming off Lake Champlain this morning. One, was coming in from east of Grand Isle into Milton, Colchester and Burlington  

The second, stronger band was focusing on places like Charlotte, Shelburne and Ferrisburgh and nearby areas. 

So far 5.7 inches of snow had fallen at the National Weather Service office in South Burlington,  as of mid-morning and I'd say half or more of that was lake effect. 

These  pales in comparison to some of those epic storms you see off the Great Lakes. But it does show Lake Champlain is capable of creating its own little snowstorms.  Especially after a warm autumn when the contrast between lake and water temperature is great, and there's no ice on the lake.

Drier air moving in this afternoon should weaken and eventually end these snow bands. 

Small Snowfall Over-Performs, White Christmas Guaranteed Vermont/Much Of New England

A nice little coating of snow has appeared around St.
Albans, Vermont. A little over two inches of snow fell
since Friday afternoon, and it was still snowing a
little as of 8 a.m Saturday 

The snow that hit New England Friday afternoon and evening was by no means a blockbuster - nobody ever thought it would be - but it did over-perform. 

By that I mean the snow was a bit more persistent and in some cases deeper than many of us thought it would be. That lead to some trouble on the roads, but also guaranteeing a white Christmas for many of us in New England, and large swaths of New York and Pennsylvania.

I don't yet have many snow reports as of early this morning. 

But as of midnight, Burlington, Vermont had received 2.5 inches of new snow.  A little more fell after midnight. As of 7 a.m. today, my place in St. Albans had 2.2 inches of new fluff.

It was still snowing a little in both cities as of 8:15 a.m,, and in fact, the pace of the falling snow had temporarily picked up a bit since dawn.   

Forecasts ahead of the snow called for one to three inches in Vermont, and it looks like a number of places will go a little past that amount.  

Especially since parts of Vermont and the Adirondacks could see another one to three inches of snow today. 

It was still lightly snowing there and in most of Vermont and adjacent New York, New Hampshire and southern Quebec as of dawn today. 

The snow yesterday and last night was never intense enough to trigger any kind of winter weather advisories, but it did make a mess on the roads for the Friday evening commute.

Traffic was heavier than usual, what with the people coming home from work and school and people heading to and from Christmas activities and shopping. 

The snow was deceptive, too.  You get an attitude, "Ah, it's only light snow." But all those car and truck tires often compacted that little bit of snow into a thin, hard to see sheen of black ice. 

The result was traffic back ups around crashes and slide offs. Interstate 89 southbound near Exit 17 in Colchester, Vermont was briefly closed Friday afternoon due to a crash.

It was slow going in the Boston area, and much of the rest of Massachusetts yesterday afternoon, too. 

Eastern Massachusetts ended up getting an unexpectedly good thump of snow, guaranteeing a surprise white Christmas in Boston and environs. Boston saw 5.2 inches of new snow Friday.  A few places in that area got around six inches of snow.

New York's Central Park received 1.8 inches of snow as of this morning. That opens the possibility of the Big Apple's first White Christmas since 2009.  (Though there was a trace on the ground in 2017. And in 2010, there was no New York snow on Christmas, but 20 inches fell on Dec. 26-27 that year).

Roads around the region were still iffy this morning, so be careful out there Road crews are out, but some falling snow is still sticking to the roads, 

 FORECAST

We've got a traditionally frigid pre-Christmas weekend underway in New England, a contrast to recent past balmy Christmas times.

As mentioned, it'll keep snowing in Vermont today. Just flurries in the valleys, really. Some of the western slopes of the Green Mountains and ski areas could get another couple inches of super light fluff today.     

The temperature continues to fall, - a trend that started Thursday. It was mostly in the teens across Vermont as dawn broke this morning, and readings will barely rise through the day.  A steady north wind will make it feel colder. 

The temperature still looks like it will fall to within a few degrees either side of 0 tonight.

The sun will come out tomorrow, as the song goes, but it won't heat us up at all. Temperatures will stay in the single numbers to maybe low teens in some of the milder spots. Those readings will crash tomorrow night, with everybody below zero by late Sunday night and towards dawn Monday A lucky few near Lake Champlain that will hold near zero.

We do see a bit of a milder trend heading toward Christmas and beyond, but it won't be as much of a warmup as earlier forecast.  Highs should reach near 20 Monday, in the 20s Christmas Eve and maybe near 30 or so Christmas.

Another weak system looks like it will spread some more light snow across the region to grace our surroundings on Christmas Eve. Gotta keep things looking traditional, so of course some Charlie Brown Christmas Special snow as we await Santa.

 

Last Week's Drenching Rainstorm Improved Vermont/New England Drought Only A Little

Yes, we had heavy rain in Vermont a little over a 
week ago, but the latest U.S Drought Monitor still
has southern Vermont in drought, (orange shading)
and the rest of the state as abnormally
dry (yellow shading)

 On Wednesday, December 11, between 1.5 and 2.5 inches of rain drenched Vermont. That was a pretty soggy rainstorms for December, dropping almost as much precipitation as some sections of the state get all month. 

It came during a drought, so that prevented any real flood problems. Despite all the rain, the episode proved how hard it is to erase a drought once it becomes established.  These things never go away after just one good rainstorm. 

Those drought conditions did improve with the rainstorm, but only to an extent. 

Every corner of the state is still regarded as abnormally dry, even though you might have encountered a little mud underfoot this week. 

But before the storm, drought encompassed all of Vermont except the Champlain Valley, which was just "abnormally dry" according to the weekly U.S. Drought Monitor. 

Last Wednesday's storm erased the drought that covered most of northern and central Vermont, but it's still ongoing across southern Vermont. Instead of 70 percent of Vermont in drought, only 23 percent is as of this week. 

All of southern Vermont except a narrow strip right along the New York border is still considered in drought. The southeast corner of Vermont, down by Brattleboro, is still actually in severe drought. 

As the ground freezes up for winter now, I imagine it will be hard to erase the drought or abnormally dry conditions in the state.  I'm guessing the only way we'll get rid of the dryness once and for all is to see some nice accumulations of snow building up, then some decent spring rains.

Vermont has gotten a little more precipitation since the storm on December 11, but not all that much. 

Last week's storminess also affected the rest of the Northeast, and drought improved  as a whole across that entire region as well.  A week early, about 65 percent of the Northeast was in drought, this week, it's down to 46 percent.

An area of extreme drought in Massachusetts was reduced in severity to severe drought. It doesn't sound like an improvement but it is.  Almost every state in the region saw some improvement, but the U.S. Drought Monitor says it's still going to take a lot more precipitation for true relief from the drought.

Hey, at least the forests aren't burning like they were back in November.  

The outlook is mixed for more substantial precipitation in the coming coming weeks. It looks like it will probably be drier than normal for the next week or so in Vermont, though there will still probably be some episodes of light precipitation.

It does seem possible the weather pattern could get stormier beyond about a week from now.

Burlington, Vermont's Longest Ever Streak Of Continuously Above Zero Temperatures Could End This Weekend.

Rime ice on trees on Burlington, Vermont's waterfront on
a subzero morning in February, 2023.  Burlington has, as
of this month, broken a record for most consecutive days
continuously above zero. That streak has a very good
chance of being broken this weekend. 

As of yesterday, Burlington, Vermont has gone - by my calculation, - 661 consecutive days without the temperature going to or below 0 degrees.  

The last time it was zero degrees, as measured at the National Weather Service office in South Burlington, was on February 26, 2023.  

The old record for consecutive days above zero was 654 days between February 22, 2001 and December 9, 2002.

In more than 120 years of records, Burlington has only had two winters in which the temperature never got to zero. 

Those were the winter of 2001-02 and last winter, which was the warmest on record.  The winter of 2001-02 used to be the warmest on record, but we've had four other winters since 2015-16 that were even toastier.

It's just another example of how climate change has affected our seasons here in Vermont. 

WEEKEND SETUP

All big streaks must come to an end, and I'd give the chances of the current continuous stretch of above zero temperatures ending this weekend at about 50/50.

We have a couple factors that favor it.   A weak system should dump an inch or two of snow on Burlington later today through Saturday morning. It will be light and fluffy and not amount to much.  But snow cover helps make clear, calm nights cooler.   

Another factors is that a strong high pressure system will be oriented to pull Arctic air down from northern Quebec. 

Then that high will settle pretty much overhead, especially Sunday night and early Monday.  When that happens, winds tend to die off and skies clear. Which means Burlington has a pretty strong shot at being at or below zero by dawn Monday. 

There's a few factors that might work against it getting below zero.  A thick, deep fresh snow cover is much more effective at refrigerating winter nights than the measly inch or two we're likely to see on the ground in Burlington this weekend. 

Winds stirring through Sunday morning might keep temperatures above zero in the Champlain Sunday morning. By dawn Monday, the core of the coldest air will be beginning to head off to the east, which could prevent a zero degree reading. 

Also, Lake Champlain is still warm and almost entirely free of ice. I don't think the warm influence of the lake will extend all that strongly to the National Weather Service office in South Burlington, which is a few miles inland from the lake.

But the contrast between the warm lake and cold air could generate clouds. If that happens, the clouds would tend to keep temperatures above zero.

So it's a tossup as to whether it will hit zero in the Champlain Valley.  It's a lock for below zero weather in most of the rest of Vermont and adjacent New York and New Hampshire. And Quebec for that matter. 

The coldest hollows of Northeast Vermont and the Adirondacks could be in the teens to near 20 below during this episode.

SUBZERO WEATHER DECLINING

Subzero nights in the Champlain Valley are still routine in most winters, but their numbers are declining. 

Attitudes like that depicted in this cartoon are getting
more rare in Vermont as the number of days that
get below zero are declining. 

Accurate daily temperature records for the winter started in about 1901-02.  In the 88 years between that winter and the winter of 1989-90, only seven winters had fewer than ten days that got below zero.

In the 33 years since then, 13 winters had fewer than ten subzero days. 

It's possible the heat island effect from added commercial development in South Burlington has contributed some to the lack of subzero nights in recent years, but climate change is almost surely having a hand in it, too.

If you're a glutton for punishment and like subzero weather, there's always the possibility we could have a  winter with a lot of 'em.  Some winters will still be cold, depending on weather patterns, with or without climate change.

But as the world heats up,  the chances of seeing a winter with dozens of subzero nights locally here in Vermont  keeps declining. 

The record for the most days that got to zero or colder in one season is 45 such day, back in the frigid winter of 1933-34. In February, 1979, we had 12 consecutive days with temperatures below zero, with the coldest in the streak at 30 below, a tie for the coldest on record in Burlington. 

 I'll almost guarantee we'll never see something like that again.