Enjoy The Last Of Vermont Fall Foliage; Wind To Remove Much Of Late Season Color This Week

Trees in my St. Albans, Vermont yard were practically glow
in the dark late Monday afternoon as autumn foliage 
peaked. With gusty winds expected later this week,
a lot of those leaves will be on the ground by Friday.

 It's been a long, gorgeous and later than usual fall foliage season in Vermont.

We've gone into the third week of October and foliage is still at peak in and near the Champlain Valley,. and in the warmer valleys of southern Vermont. 

That's quite a bit later in the month than in most years, but then again, foliage seasons have been coming later as climate change takes hold.

Elsewhere in Vermont the color is past peak, but there's still pockets of bright autumn glory to be found.

Sunshine, light winds, and, on Monday, record high or near record high temperatures helped keep the foliage on the trees

Enjoy it for the next couple of days. We'll soon take a big but admittedly incomplete leap into stick season. 

Winds have already picked up from the nearly dead calm we saw Thursday through Saturday.  It's merely just kind of breezy, but each gust yields a blizzard of leaves from many trees.

Warm breezes will increase Wednesday ahead of a sharp cold front due Wednesday night or very early Thursday. In the Champlain Valley, we could easily see winds gusting to at least 30 mph. 

Then, when that cold front comes through Wednesday night, we won't see much rain, but some gusts could reach 40 mph just after the front blows through.  We'll be waking up to a different landscape Thursday morning compared to the beautiful one we're seeing today.

All is not lost, however. We will have fewer leaves on the trees, but we'll still have some remarkably late season color left in the banana belt sections of Vermont. This beginning to remind me of some recent year, like 2021, when unusually warm autumns allowed some nice spots of fall foliage to linger into November. 

  

Most Widespread Frost So Far This Autumn In Vermont, Which Is REALLY NOT Saying Much

A ripe, ready to pick tomato in my St. Albans, Vermont
garden today. I picked more than half a dozen 
tomatoes just last Friday. Before this year, the latest
I ever picked a good, not frost-damaged tomato
was on October 1. 

 The National Weather Service has issued a frost advisory for large swaths of Vermont overnight and early Tuesday morning, the most widespread such alert yet this autumn.  

Which is wild, because the frost advisory is saying much, at least compared to an average autumn.

 Most of the Green Mountain State away from Lake Champlain should have had a killing freeze by now, if things were normal. But even as the trees go bare in preparation for winter, sensitive plants outdoors are still untouched, and in some cases thriving. 

The frost advisory, in effect from 2 to 8 a.m. Tuesday, covers central, eastern and southern Vermont. The Northeast Kingdom is exempt from the frost advisory, since their potential growing season is considered over.

However, most of that area of Vermont has very oddly not had a frost yet, so people are still probably hanging in there with sensitive outdoor plants in normally chilly towns like St. Johnsbury, Lyndonville and even sections of normally frigid Island Pond near the lake. 

Even in the Northeast Kingdom, it might be worth it to try to protect plants for a little while.

A frost advisory means temperatures could dip into the low and mid 30s, enough for patchy frost to develop. It doesn't have to get down to 32 degrees to get a frost, because temperatures on the ground are often colder than five feet off the surface, where temperature readings are usually taken.

A frost advisory isn't as dire as a freeze warning, which means temperatures are expected to get below 32 degrees and would really kill off outdoor plants. 

A freeze warning is NOT in the cards for tonight.

The first fall freeze of 2023 is already later than normal for almost all of Vermont.  Depending upon which central Vermont community you live in, on average you should have had the first 32 degree reading of the season sometime in the last week of September or the first couple days in October.

Burlington's average first autumn freeze is around October 8, so we're a little past that. Right along Lake Champlain, in places like South Hero, the average first freeze is around October 19.

It also looks like today's high temperature in Burlington will be below 60 degrees, the first time that's happened since May 17, when we had that unfortunate, and destructive late crop killing freeze.

I don't have specific record on this, but I'm pretty sure this is one of the latest if not THE latest first sub-60 high temperature on record. I've often seen highs in the 40s this time of year, so it has been consistently mild or warm, or even hot for early to mid autumn. 

To give you an idea of how cold it can be this time of year, at least in the past, on this date in 1979, the HIGH temperature in Burlington was 37 degrees, and we had 1.4 inches of snow that day. 

There might be more areas of frost Thursday night and Friday morning, but we still don't see evidence of a hard autumn freeze coming up anytime soon. Temperatures in Vermont should remain seasonably cool, but not at all unusually chilly for at least the next week. 

After Rough Summer, How Will Vermont Fall Foliage Fare?

A fungus brought on by Vermont's extremely wet, humid
summer afflicts these sugar maple leaves in Richmond,
Vermont. Though the fungus won't harm the trees, it 
could somewhat mute fall colors this year. 

UPDATE: I should have mentioned when I first wrote this post that people who visit Vermont this fall should have no trouble seeing the sights and the beauty and getting around. 

There's been questions from out of staters as to whether they can actually come up to Vermont, given the devastating floods we had in July.

The answer of course is a resounding yes.

The roads are back open, the vast majority of businesses that cater to tourists visiting Vermont were either undamaged by the flood or have re-opened. 

That's not to minimize the continued suffering and uncertainty for the thousands of people directly affected by the flood.

But visitors will see our usual beautiful landscape intact

PREVIOUS DISCUSSION

The first fall colors of the season are starting to pop up in Vermont, a little late, but still noticeable in just a few isolated pockets.    

The swamp maples have really started to turn red, and some of the more precarious sugar maples out there are showing some isolated pockets of  color.  Even so, it's still mostly green out there. Once again, it looks like fall foliage season in Vermont tis running a little late. 

So, will this season be a vibrant one, or a bust?

 First of all, predicting the timing and especially the vibrancy of fall colors is harder than forecasting the weather, so expect some misses on this issue.  

Maybe more importantly, you'll definitely find a lot of beauty this fall. It might or might not be as vibrant as the past couple of years, but it will still be stunning. 

The last two years brought perfect summer and early fall weather that led to brilliant foliage seasons. However,  I'm personally leaning toward a prediction of a somewhat more muted autumn show in 2023.  I suspect some of the more vibrant reds that really make the colors pop might be missing this year. 

As we well know, it was an incredibly rainy, incredibly humid summer, even if it wasn't exactly the hottest one in memory. All that moisture lingering everywhere encourages fungi and other issues on leaves.

I've noticed in many locations, many of the leaves on sugar maples are turning yellow with spots of black, and falling prematurely. That's a fungus caused in large part by the rainy summer weather. This ultimately won't hurt the health of the trees, but it could well mute the autumn show.  At least i some areas. 

Another wild card is the intense, record breaking freeze Vermont suffered on May 18.  The freeze destroyed new oak, sumac and ash leaves. They shriveled up, turned black and fell off. By the end of June, these trees put out a new set of leaves, but the foliage was thinner than we otherwise might expect. 

Most of the cold hardy leaves, like on maples, beech, poplar and such, but I don't know whether there was hidden damage that could affect fall color.  

The Vermont landscape still looks really green now that
we're into mid-September. Warm weather this summer
and September so far appears as if it might make 
for a somewhat late fall foliage season. 

There's another more permanent foliage disappointment starting now. The emerald ash borer long expected to go on attack against Vermont's numerous white ash trees, is really going on the attack  now. 

This summer, I saw big swaths of dead and dying ash trees, all victims of the emerald ash borer. Over the coming few years, this awful bug will decimate Vermont's ash trees, as it has in other states.

This is a big disappointment, of course. Ash trees add variety to the fall foliage pallete,  They punctuate the reds and oranges of hillsides with pops of gold and purple.   So their loss will be hard to take.  

On the bright side, another forest-wrecking bug, the spongy caterpillar, once known as gypsy moth caterpillars failed to make an appearance this year after a couple years of these little buggers defoliating big swaths of Vermont forest. 

Leaves usually grow back after the caterpillars leave for the season in mid to late summer, but the returning foliage tends not to be as thick or prone to great fall colors had the trees not been touched. 

This year, a short but intense Arctic outbreak in early February killed many of the overwintering caterpillar eggs. The humid summer encourage a fungus that kills the caterpillars. So I guess there was one small benefit to all that rain through June, July and August. 

In general, it's thought that a bright, dry September with chilly nights and mild days encourages a better fall foliage season. So far this month, the pattern has been mostly wrong for that. We had a midsummer style heat wave between September 3 and 8.  Nights have ranged from sort of on the warm side to downright muggy and toasty.

As of Tuesday, the temperature in Burlington had yet to fall below 50 degrees this month.  These warm conditions appear to be making fall foliage season late. As of this past weekend, many hillsides in Vermont looked as green as they do in July, with no hints of color yet. 

As climate change has made conditions warmer, there has been a general trend toward a later fall foliage season. I remember growing up as a kid that fall foliage season was largely over by October 10.  Now, most years, you can find good color in the warmer valleys during the third week of October. 

Two years ago, there was still pockets of pretty fall colors in the opening days of November. 

Temperatures have turned decidedly cooler over the past couple of days as we inevitably head deeper and deeper into autumn. 

Long range forecasts continue to call for generally above normal temperatures into early October, but above normal doesn't mean the same as it did a few weeks ago. Even these warm spells will feature chilly nights and shorter days that will encourage the leaves to turn color pretty fast between now and mid October. 

Video: Taken over the past few days, it shows fungus afflicting sugar maple leaves and causing them to drop prematurely.  It also includes a view of hillsides a few days ago around Richmond, Vermont still looking very green for mid-September. Click on this link to view, or if you see image below, click on that: 

 

Will A "Sudden Stratospheric Warming" Postpone Spring?

Just one forecast for temperature anomalies in the 
lower stratosphere toward the end of this week. All that
orange represents something called a Sudden 
Stratospheric Warming. This can disrupt the polar vortex,
which in turn can cause cold, stormy weather in
the mid-latitudes in March. 

As I keep harping on, it's been a warm winter. Really warm.

Since the winter of 2022-23 is turning out to be a dud for cold and snow lovers, a lot of people are probably saying, "Let's get on with spring already, then."

Not so fast.

Because Ma Nature seems intent on punishing us awful humans, she's launching something called a "sudden stratospheric warming."

It could mean that winter finally hits - in March. 

As the Washington Post reports: 

"Several miles above the North Pole, an atmospheric chain reaction may soon initiate that sets off important changes to the weather pattern across the Northern Hemisphere in the coming weeks. 

In places where cold and snow have mostly remained absent, the sequence could trigger a wintry revenge. However, it's still unclear how significant or long-lasting any changes may be and exactly where and when they would occur."

The not all that well understood phenomenon starts with the stratosphere over the northern reaches of the Earth suddenly and abruptly warms up, by as many as 60 degrees.

When this happens, it usually disrupts the polar vortex, that whirl of cold that's usually somewhere up in the Arctic.

The polar vortex has been mostly "well behaved" this winter, sitting high up in the Arctic. That has for the most part prevented very cold air from plunging into places like the United States and Europe.  Which explains the warm winter both areas have had. 

The polar vortex did get disrupted for other reasons recently, making it plunge down toward New England and give us that brief bitter blast of Arctic air on February 3 and 4. But, the vortex quickly got its act back, together, and settled itself far to the north again. That's why it has once again warmed up.

A sudden stratospheric warming is more likely to disrupt the polar vortex. That means weather mischief somewhere in the mid-latitudes. Think the United States, southern Canada, Europe, China, Japan, places like that. 

Even if we do see that sudden stratospheric warming, or SSW, we don't know if it will have a big effect or whether it will be a nothing burger. If it does have a large impact, we don't know where that might be as of yet. Could be the western U.S., or could be the East, who knows? Or it could focus on Europe.

Whatever happens, generally speaking, the effects of a SSW last four to six weeks. 

The most recent example of a big headache created by a SSW, we only need to harken back to late February and March 2018. 

In late February, 2018 the so-called "Beast From The East" slammed Great Britain. Frigid winds from Siberia flowed westward to the UK, causing some of the most intense cold and blizzards in recent memory.

More locally here in Vermont, we had a remarkably warm February, 2018 which culminated in temperatures as high as 70 degrees in Montpelier, which is their all time hottest temperature for February. Burlington reached 69, which would have been the hottest February reading ever if not for a 72 degree temperature spike the previous February.

Then came March, 2018, once that year's SSW took full effect. In mid-March, up to 30 inches of snow fell in Vermont. Along the New England coast, four snowy nor'easters battered the region during the month. 

It really took until late April, 2018 for temperatures to consistently return to normal or above.

Of course, 2018 was almost a worst case scenario. Chances are it won't be that bad. Or if it is, it won't last as long, Or it won't affect us here in Vermont all that much. You never know. 

The last SSW to occur was in January, 2021. That helped lead to a record breaking cold wave in the Plains and Southeast in February, 2021. It focused on Texas, causing deadly blackouts amid the cold, killing dozens of people. 

That 2021 event was a yawner here in Vermont. We just kind of had average weather in February and and March that year. 

A SSW more often affects the weather in northwestern Europe than it does the United States, but the U.S. sees the effects often enough. I'm betting on at least some cold weather in March here in Vermont. That means more frequent below normal temperatures than we saw in January and February.

If the SSW actually happens, it will probably begin this week if it hasn't already started.  It takes a week or two after the stratospheric warming to have much effect on where people live.,

That would take us into early March. 

It's a little too soon for long range forecasts to accurate predict what the weather will be like in early March.  But some of the preliminary long range computer projections seem to indicate a switch to colder, stormier weather in the eastern U.S., including New England, possibly arriving in the last few days of February and continuing at least into the opening days of March.

That's not set in stone, but the chances are there. 

Besides, we're overdue for a colder than average month in Vermont. February will be warmer than normal, meaning the last time we had a chillier than average month in Burlington was September. Even that was a fraction of a degree cooler than normal. And it was the "new normal" which is skewed toward warmer averages than decades ago.

And remember this non-scientific adage that has always worked for me: No good weather in Vermont goes unpunished. If you got a break in the weather in one month, you'll pay dearly the next. 

 

Burlington To Have Latest First Freeze On Record With Big Asterisks (Snow Is Late, Too)

Purple blooms and sunflowers continue to survive amid
the fallen leaves in my St. Albans, Vermont gardens.
We haven't had any really hard freezes yet this autumn. 

 Technically, the National Weather Service office in South Burlington will set a record on Thursday for the latest first autumn freeze on record.   

The current record for latest freeze, as measured at the Burlington International Airport, is October 26, 2018.  It did get down to 33 degrees at the airport on October 11, but that wasn't quite a freeze.

There are TONS of asterisks to this record, however. 

Measurements at the airport only go back to 1941, so this will be the latest first freeze since around the beginning of World War II. Weather measurements for Burlington prior to 1941 were taken closer to Lake Champlain. 

In general, the closer to Lake Champlain you are, the less likely you are to have early frosts. The record for latest first frost as measured prior to 1941 is November 1.  (I'm not sure of the year),

Burlington, at least the airport if not downtown, could well see a frost by November 1. Strong high pressure is forecast to settle in overhead around Friday and Saturday (October 28 and 29). 

The air associated with this high pressure is not likely to be really cold. It's not coming from the Arctic.  But by this far into autumn, anytime you get a clear, calm night, you should expect a frost. And chances are high we'll have just that kind of weather. 

Fall and spring freezes are incredibly local affairs. One neighborhood might stay just above 32 degrees while a freeze hits just two doors down. It's just a matter of whether the air was calm enough long enough on a clear early morning to allow temperatures to dip below 32 degrees.

For Vermont as a whole, most of us had a freeze somewhere either around October 3 or in the October 10-11 time frame. That's more or less average timing for a first freeze of the autumn. 

Even so, we haven't had a lot of cold nights, and the freezes we have had weren't especially harsh. I've noticed that even though most of the leaves are off the trees, garden and potted flowers continue to happily bloom in much of Vermont. This is the time of year I clear out my perennial gardens, but I've been reluctant to cut down parts of them. They're still pretty. 

The quirk of no freeze yet at the airport in South Burlington makes for this weird stat: A record cold wave hit the South last week.  So at least officially, southern cities like Jackson, Mississippi, Birmingham, Alabama and Tallahassee, Florida had their first freeze before Burlington, Vermont. 

The first snows of the season in Vermont are late this autumn, too, but so far, that's not setting any records. 

I couldn't really find any data on the latest first trace of snow of the season in Burlington. But I do know the average date of a first snow flurry of autumn is October 15, so we're past that. I know we've seen many years in which the first couple of snowflakes of autumn held off until November.