Early Sunday Afternoon Update: New Severe Storm Watch About To Go Up In Vermont, Surrounding Areas

UPDATE 6:30 pm

Relatively dramatic clouds, but no severe weather in 
northwest Vermont, with this view of Georgia, 
Vermont as an example.

The expected severe threat in Vermont is turning out to be a bust. 

On one hand that's good news, since people aren't picking up the mess left by severe weather.

Of course, the bad news is something went wrong with the forecast, at least in much of Vermont. 

A line of showers did produce a gust front with 30-35 mph winds. There might have been locally somewhat higher gusts. I know a tree fell in Bakersfield, which took down a power line and  started a fire that closed Route 36 near the intersection with Route 108. 

A severe storm or two could still pop up in southeastern Vermont until about 8 p.m. or so, but the the threat isn't super high. 

In northwestern Vermont, temperatures were crashing toward the 50s behind the cold front. Light rain showers will probably linger for a few hours here and there. Nothing severe though! 

I'll have more details in tomorrow morning's post about why the forecast was off, at least for the most part in Vermont 

UPDATE: 1:15 pm

Environment Canada has issued a tornado watch in southern Quebec in areas closest to the Vermont, New Hampshire and Maine borders.

Also, 15 minutes after I finished writing this update post (around 1 pm.) I now see convection starting to fire up in New York State. That will develop fast for the next few hours.

PREVIOUS DISCUSSION

NOAA's Storm Prediction Center at around 12:30 today issued a statement that they were getting ready to issue a severe thunderstorm watch for northern New England. 

This is as expected, because the risk of severe weather for this afternoon has been advertised for days. 

The Storm Prediction Center's statement is forecasting the risk of  damaging winds, large hail, and perhaps a tornado or two in northern New England. 

As of 12:45 p.m., there was almost no shower or storm activity anywhere near Vermont.  I'm a little surprised nothing has gotten going yet. But that should change soon. 

A line of thick clouds was entering the St. Lawrence Valley of New York and I think the difference in the amount of heat to the east verses under the cloud bank will be where the main line of storms start. So this will be an event pretty much confined to the Adirondacks and Hudson Valley, then points east into New England.

NOAAs's Storm Prediction Center anticipates a
severe thunderstorm watch to be issues soon in
northern New England. 

Some thunderstorms will probably develop ahead of this expected line as well. We'll have to watch those especially carefully, because the storms ahead of the main line can form into supercells. Supercells are especially prone to throwing out damaging winds gusts, car-denting hail, and that quite low but real tornado risk. 

Cleanup in Williston, Vermont this morning after severe
storms mowed down several trees in town Saturday.
Additional severe storms could create added damage
in a few Vermont towns today. 

This is especially true in the northern half of Vermont, northern New Hampshire and much of Maine. 

I'm sure that severe thunderstorm, or perhaps even a tornado watch will be in effect by 3 p.m. if not well before that. 

We're most at risk for storms, again, some of those damaging, between 2 and 9 p.m today. Western Vermont will see the storms begin and end soonest, while eastern Vermont will be last to finish up this evening. 

This all comes after a few severe thunderstorms in Vermont yesterday. I was in Williston this morning and was impressed by the number of fallen branches and trees. 

Some of the fallen trees were huge. Route 2 on French Hill between Williston and Richmond was closed this morning, presumably because of storm damage. 

 

Saturday Storms Did Pop In A Few Areas: More Vermont Severe Weather Today

A volatile looking sky over St. Albans, Vermont Saturday
evening as severe thunderstorms passed by well north
and south of town. 

 Saturday's storm development, almost surprisingly, developed about as expected in Vermont. That was just round one.  Round 2 of severe weather is still in the forecast today. 

A derecho developed around Michigan early Saturday then roared through the metropolitan areas of Toronto, Ottawa, Montreal and Quebec City.  I saw one estimate that indicated that since this hit so many urban areas, the line of storms affected half of Canada's population. 

Damage was especially intense in and around Toronto. 

The derecho passed north of Vermont, but was a catalyst to break a cap, which was a warm layer of air high above. 

This allowed thunderstorms to develop rapidly in northern New York and Vermont and race across the area, mostly along and north of Route 2.  As expected, the intense storms were hit and miss, and most people did not have anything too intense.

Even so, winds of at least 55 mph downed trees in Williston. Quite a bit of tree damage was reported around Eden, too. Another severe storm skirted the International Border between Alburgh and Franklin, dumping hail up to the size of half dollars and causing additional tree damage.

Another wave of thunderstorms - not severe but with plenty of lightning - zipped across northern Vermont late last night. That storm caused a power outage lasting two and a half hours at my place in St. Albans. 

It'll be quiet this morning and then we have another risk of those strong to severe storms. The National Weather Service in South Burlington is thinking today's storms will be a little easier to forecast compared to yesterday.

Until the storms started developing Saturday, there were questions as to whether there would be enough of a trigger to launch those storms. Turned out there was, at least sort of.

Today, we know we'll have the trigger in the form of an approaching cold front and something called a pre-frontal trough out ahead of it. A pre-frontal trough is very common with summer cold fronts. It's just a pocket of lower pressure ahead of the cold front that causes a bit of a wind shift. That's an easy trigger for storms. 

So we'll end up with clusters of storms along this pre-frontral trough this afternoon, and probably with the cold front itself. Usually the pre-frontal thunderstorms are the stronger ones. 

This will be a west to east affair, starting around  1 or 2 p.m.- ish in New York and proceeding across Vermont from mid-afternoon into the early evening. 

This means the activity will come through after the University of Vermont's outdoor graduation ceremony today. But if you're going, drink plenty of water and bring sunscreen. It's very warm and quite humid out there 

As of early this morning, Vermont remains in a slight risk zone for severe storms, a level 2 of 5 alert. This means the biggest threat from the storms is, as usual, strong gusty winds. Most people won't see damage, but there will be pockets in which the wind will be strong enough to toss down trees and power lines once again. There could be some isolated areas of large hail, the size of quarters or half dollars again. 

Once again, there's a very, very remote chance of a quick spin up tornado, but that's quite unlikely. There's a slightly greater chance of a quick twister in western Maine. 

It'll turn noticeably cooler overnight tonight, and the first half of the week is still looking nice, with comfortable afternoon temperatures in the 60s to around 70

 

UPDATE: Could Be A Really Interesting Afternoon/Evening In/Around Vermont

Interesting satellite image early this afternoon. That big
blob to the left are intense thunderstorms around Toronto.
There's some sort of boundary heading east across
northern New York. That COULD be a trigger for
storms in the next couple of hours, but a warm layer
aloft might squelch that. Storms are developing
in Quebec, a few of which might become tornadic
thunderstorms up there. Outflow from the Canadian
storms MIGHT help trigger strong storms here later today.

UPDATE 3 pm.

NOAA's Storm Prediction Center has indicated they will likely soon issue a severe thunderstorm watch for far northern New York, Vermont north of Route 2, northern New Hampshire and western Maine. 

That band of severe storms from Ontario could clip the region. Other storms were starting to fire up in Quebec and might sag south toward the International Border with time later this afternoon.

These storms, in they make it into our region, have the potential to cause really damaging winds. The Storm Prediction Center says a tornado can't be ruled out. 

PREVIOUS DISCUSSION

 No promises, but things are shaping up to be potentially wild in parts of Vermont, especially north later today.   

They're certainly pretty wild in southern Canada.

As of 1 p.m. a cluster of intense thunderstorms was roaring through the Toronto metro area, packing winds of up to 85 mph. Lots of damage has been reported. It's racing east/northeastward toward Quebec.

I think this patch of storms will go by to our north, but outflow boundaries - the remnants of the storms' gusts fronts, could head south. These boundaries can act like mini cold fronts, acting as a trigger for abrupt, severe storms. 

Meanwhile, some forecasts are calling for supercells and tornadoes in southern Quebec and far western Maine today. These storms might also generate outflow boundaries, those little cold fronts, to help trigger more storms. 

Lots of things are in place for intense storms today. The main thing blocking the development of these storms is a layer of warm air aloft.  It's possible those outflow boundaries could be enough for wannabe thunderstorms to pop through that warm layer and really develop.

Also, lake breezes in the Great Lakes and even Lake Champlain could create enough of a disturbance to help trigger upward motion and storms. 

Skies really cleared up this morning, too, so the hot sun is helping to destabilize the atmosphere. 

There was a weird, narrow line of clouds in northern New York at 1 p.m. that also represents some sort of boundary. Things can get going ahead of that, but unlikely.

There's cumulus clouds out ahead of this line of clouds, but a patch of clear skies behind it. That patch of clear skies indicates sinking air. Sinking air hinders thunderstorms. So if that little line of clouds goes through Vermont uneventfully this afternoon that patch of sinking air could move in and MIGHT postpone storm development until late afternoon or evening. 

So yes, there's a lot of ifs, ands or buts with this afternoon's forecast. There's TONS of potential for some rocking, severe thunderstorms in and near Vermont later today. The only question is whether there will be enough of a trigger to actually launch them. 

If anything develops, the main threat still looks like it would be strong, damaging winds. Hail could be an issue to. Since we're in fairly close proximity to that "spin" the the atmosphere over Quebec, there's still a very, very low, but not zero chance of a brief spin up tornado in northern Vermont - IF the storms actually erupt.

It's one of those days that might end up being super wild, or a big yawner.  Rare that we don't know what will happen just a couple, few hours before the event, but there you go. 

 

Hot, Noisy Weekend In Vermont, Then Spring Returns

A long skinny zone from Texas to Maine, including
Vermont, has some risk of severe thunderstorms later today.

 The forecast has only undergone some minor changes for this weekend, so expect a lot of sweat and a fair amount of noise from the weather here in the Green Mountain State.

We still have a heat advisory for the low elevations of western and southeastern Vermont. I have questions as to whether it will get as hot as forecast, especially in northwestern Vermont. 

Debris clouds from storms that developed in the Great Lakes, Ontario and western Quebec are moving through.  These clouds might not fully clear out, and that would keep the temperatures down a little for the day.

Still, it will be very warm and oppressively muggy. 

Meanwhile, NOAA's Storm Prediction Center has bumped us up from a marginal to slight risk of severe storms today and this evening. That's level 2 of a five point scale of risk. 

As described over the past couple of days, we're still looking at both the instability that would encourage strong storms and the cap, or warm layer of air aloft, which would squelch them. Which of the two will win?

It's looking like the result of this tug and war in the atmosphere will be hit or miss storms. Where storms can get going this afternoon, they'll quickly become strong. I think, but don't guarantee, that the afternoon storms, if they develop, will be few and far between. But again, those isolated storms could easily pack a punch.

Additional storms expected to form in New York this afternoon could arrive in Vermont this evening, again in hit or miss fashion. Those evening boomers, I suspect, will be somewhat more widespread, especially in northern Vermont. Again, though, hit and miss, not everybody gets rocked. 

The main threat from any storms later today will be strong, straight line winds and hail up to the size of a quarter.   Since it's so humid, some storms could have briefly torrential rain.  There is a very, very low, but not zero risk of a quick spin up tornado, but I'm really doubting that, to be honest.

 We can only keep an eye on things and see how they develop. 

The severe storm risk is more limited to
our neck of the woods Sunday. 

Tonight's not going to be great for sleeping. First, it will be muggy and sticky. We could also see a few thunderstorms roam through here and there to wake you up if you do manage to sleep. 

Tomorrow's still a day to watch.  Still no guarantees, but conditions do seem favorable for a line of strong storms to bust through in the afternoon as a cold front comes in. Some of the storms could be strong to severe, with - again - damaging straight line winds the main threat. 

There could be hail, and again, a very, very, low risk of a quick spin up twister along the line of storms, but again, doubtful. (You never know, though, right, Charlestown, New Hampshire?).

Sunday afternoon's storms, at least some of them, could also contain torrential rain. But the storms will be zipping right along, so it won't rain hard for long in any one place, so I'm not too worried about flash flooding. 

NOAA's Storm Prediction Center still has us in a low risk (Level 2 of 5) for severe storms on Sunday.

We turn cooler and springlike again for the first half of the week.  We'll have to watch the second half of the week, as there's some (very uncertain) potential for some heavy rains. 

April Was World's Fifth Hottest, Continuing A Consistent Trend

Most of the world was once again warmer than the average
of all the years since 1880. Only the eastern Pacfic
and northwestern North America were on the cool side. 

As I wrote a month ago, it seems like on a global basis, every month for at least the past year or so has been around the fifth hottest on record.  

Add April, 2022 to that list. The month tied with 2010 as the fifth hottest on record, says NOAA's National Centers for Environmental Information. 

So, we'll do the same thing we' e done every month, with this slightly updated sentence, taking into account April's global temperature, and quote this familiar sounding sentence from the April report: 

"The 1 warmest April months have occurred since 2010, with the years 2014-2022 all ranking among the 10 warmest Aprils on record. This marked the 46th consecutive April and the 448th consecutive month with temperatures, at least nominally, above the 20th century average."

As always, there were a few small cold pockets in a world of heat. 

North America did manage to have its chilliest April since 2018, which isn't really saying all that much. That was driven by persistent chill in southern Canada and the northern United States west of the Great Lakes. 

The only other notable cool spot, at least relative to the rest of the world, was the eastern Pacific Ocean.

That was a sign that the La Nina pattern is still going full throttle. La Nina is a periodic cooling of swaths of the Pacific Ocean. This normally has a slight cooling effect on the world's temperature as a whole.

But as we've seen over the past year, this "cooling" pressure is preventing individual months from being the hottest on record. But we're still scoring in the top 10 each month.  This is all an ominous sign for when we someday finally flip over to an El Nino, which warms both the eastern Pacific Ocean and the world in general. 

A record setting warm month would likely really set off some dangerous, extreme weather events across the globe. As if we're not having enough of them already. 

Every April temperature for the world as a whole, 
the departure from normal, since 1880. See a trend?

La Nina is forecast to last for several more months at least. That's bad news if you don't like hurricanes in the Atlantic Ocean and Gulf of Mexico threatening the U.S. coastline. 

La Nina tends to encourage Atlantic hurricanes. It's a big reason why we've had such busy hurricane seasons yearly since 2017. This year is looking bad, too.

Pretty much all the hurricane forecasters are calling for a busy Atlantic hurricane season. The only question is how many of these storms end up hitting the coast. 

The first four months of the year, taken together, are also the fifth warmest on record. Given the ongoing La Nina the year at this point "only" has a 27.8 percent chance of being among the five hottest on record. It's pretty much a lock already for being among the 10 warmest. 

In April, no nation or territory established an all time record high temperature,. That's to be expected, since April is the middle of spring or autumn, depending upon which hemisphere you're in. Obviously, national heat records would be established in the summer. 

However, so far this year, three nations - Paraguay, Uruguay and Australia - have established or tied national heat records. 

 

More Needed Rain, And Multifaceted Challenging Vermont Weekend Forecasts

Yesterday we bought the annuals we need to make our pots
planters and window boxes look lovely for the summer.
It's going to be hot, humid work starting this job
over the weekend. 

 We're used to ifs ands or buts in Vermont weather forecasts as the Green Mountain State can be a challenging place to forecast what the heck will come out of the sky, if anything.  

This weekend is a classic case in point, with questions about how hot it will get both days, whether severe thunderstorms manage to pop up later Saturday, and how widespread showers and storms might be on Sunday. 

Prepare for surprises, but also prepare to sweat it out: It's going to be an oppressively warm to hot, and very humid weekend. 

First, though, a quick review of yesterday's little soaker. In northern Vermont, the rain was a little heavier than forecast. Which is a good thing, to keep things well wetted down.  Most of us got a quarter to a half inch of rain, with a few drier spots here and there. 

In Burlington, yesterday's rain brought the month's total so far in May to 2.2 which is right at normal for this date of the month. That's also more rain than fell all of last May, when we had just 1.42 inches. 

Next up, let's untangle the weather for the next few days. Do note that the forecast will almost definitely change one way or another, but this is what it looks like at this point:

TODAY

Today will be a big transition day. It's starting off chilly with partly cloudy to clear skies, with plenty of areas of dense fog. The fog will burn off quickly, and temperatures will zoom up to around 80 degrees by mid to late afternoon. You'll notice humidity starting to creep up as well. 

The question marks for today and this evening are a fairly strong disturbance passing to our south and a weaker one tonight to our north. The southern one will probably set off a few severe thunderstorms in and around Pennsylvania. 

Up here, definitely nothing severe, but some showers of a rumble of thunder could develop overnight because of the two systems. It will end up being muggy overnight, too.  

SATURDAY

Hoo-boy, you're going to be hot. Temperatures in the warmer valleys could easily get to 90 degrees unless more clouds roll in than expected. This hot spell is going to be much more humid than the one last week, so it will feel worse. 

Bad enough for the National Weather Service to hoist Vermont's first heat advisories of this summer season. Those heat advisories are in effect Saturday afternoon and evening in the Champlain Valley and low elevations of southwestern Vermont from about Milton south, and for the lower Connecticut River Valley from about White River Junction south. 

The heat index in the advisory zones will be around 95 degrees. If you're outside the heat advisory zone, it's still going to be uncomfortable.  At this point, the actual high temperature for Burlington Saturday is 92 degrees, which would tie the record for the date. We shall see! 

The forecast for thunderstorms Saturday hasn't changed much from the CAPE vs cap discussion I had yesterday.

CAPE, the potential for storms in the atmosphere will be really high, but you need a trigger for storms, and a way for them to get going. A layer of warm air aloft - which is the cap - will tend to prevent the towering updrafts that lead to thunderstorms. 

NOAA's Storm Prediction Center is maintaining a slight
risk for severe thunderstorms  - level 2 of 5 alert levels
for us on Sunday

However, the air tomorrow will be volatile with the CAPE. If any updrafts break the cap, chances are the updraft would quickly become a strong to severe thunderstorm.  As it looks now, any storms that form late tomorrow afternoon or evening will be few and far between so that most of us will be unaffected. But if one forms near year, watch out, it could be a doozy.

NOAA's Storm Prediction Center has us in a marginal risk zone for severe storms Saturday, the lowest level of alert in a five point scale. 

Saturday night will be stuffy with just a chance of a lingering storm. 

SUNDAY

Everything on Sunday depends on the timing of a cold front, how many clouds are out ahead of it, and how hot it gets.

We know Sunday will be quite humid.  If there's some sun, as currently expected, we'd get up into the upper 80s.

With the cold front approaching there's a decent shot of thunderstorms in the afternoon or evening, and some could be severe. 

How extensive the storms will be will depend on a few factors. If most of the day is cloudy, that would minimize instability and reduce the chances of severe weather. 

If we have a period of sunshine in the late morning to early and mid afternoon that would increase the chance of severe weather. 

We'll know more details as we get closer. For now, NOAA's Storm Prediction Center has us in a slight risk zone for severe storms. 

MONDAY

Blessedly much. much cooler and much, much less humid. 

A Rather Wild May Weather Month Continuing In Vermont, Elsewhere Too

On this cool, cloudy morning, the progression of spring
continues in my St. Albans, Vermont gardens. The
daffodils have faded away, and now the irises and 
peonies are budding, preparing for their show. 

After a stunningly gorgeous, perfect spring day on Wednesday in Vermont, we're back to the roller coaster ride of changeable weather.  It's a pattern that's affecting much of the nation. In some places much more dramatically than here in New England. 

We'll start with the local stuff first. Today will certainly not be as brilliant as Wednesday as a fast moving weather disturbance zips through.  

We're starting off cool today. There's even a little frost in the cold hollows of the Northeast Kingdom. With the clouds with this weather disturbance now in place, temperatures won't be able to rise much today. Especially as the rain moves in.  

Most of us will stay in the 50s, which is more than 10 degrees on the cool side. This relative chill is not that odd for this time of year. (The record lowest "high" temperature on this date in Burlington is 43 degrees in 1976).

Rainfall will only amount to a quarter inch today, give or take.  There might be some embedded heavier showers or even a rumble of thunder which would create locally higher amounts of rain. But we'll fall far, far short of any flooding concerns. It's just a little water for the gardens so that you won't have to drag the hoses to the raised beds today. 

The weather variety show continues on Friday as things turn dramatically different again. Winds will turn gusty from the south, especially in the Champlain Valley. By Friday afternoon, instead of 10 degrees cooler than normal, we'll be ten degrees above normal - near 80 degrees. 

Another couple of acts arrive for our variety show on Saturday. It will be a sultry summer day, with highs in 85 to 90 degree range. It will be humid. 

As the National Weather Service in South Burlington points out, some ingredients for strong storms will be in place by later Saturday afternoon, but there won't be much in the way to trigger much of anything.

When forecasting thunderstorms, one of many things meteorologists look at is CAPE, or Convective Available Potential Energy.  This is all a way to determine instability in the atmosphere and the strength of updrafts. The higher the CAPE value the higher the risk of thunderstorms, some strong to severe.

Here in Vermont, if you see CAPE values above 2,000 joules per kilogram (J/kg) we have ingredients for bopping boomers for sure.  CAPE values Saturday afternoon or evening are expected to be in the 2,500 to 3,000 J/kg range.

But CAPE is just one ingredient. You need multiple ingredients, not just flour, to make a cake. Likewise, numerous ingredients need to come together to create a tasty thunderstorm. 

It's unusual to see northern New England and Near
York highlighted in the Storm Prediction Center's
four day outlook, but there we are! 

On Saturday, just to make things confusing, a cap will be fighting the CAPE.  A cap is a warm layer in the atmosphere that stops those CAPE updrafts in their tracks, preventing thunderstorms from developing. 

Sometimes updrafts can break through a cap. There's a chance that could happen in a couple places in Vermont toward the end of the day Saturday. 

If that happens,  a couple strong thunderstorms could abruptly develop.  NOAA's Storm Prediction Center has the northern half of Vermont in a marginal risk zone (level 1 of 5 risk category) for severe storms Saturday for this reason. 

More interestingly the Storm Prediction Center Day 4 outlook for Sunday has us in a risk zone for severe storms. Usually, when the SPC is bullish on severe storms that far in advance, you really want to pay attention.

Still, everything has to come together just right for this to happen. Sunday could be an active day, or it could be a bust. It's just something to watch for now.  

The variety show continues after Sunday when the hot, humid air is replaced by the kind of weather we had yesterday. A springtime beauty curtain call, if you will. 

COLORADO VARIETY PACK

If you really want variety, go to Colorado. In some parts of that state, they were under a severe thunderstorm watch last evening, and find themselves this morning simultaneously under fire alerts and a winter storm watch. 

Hot, dry winds today will increase the risk of wildfires in Colorado and most of the rest of the Southwest today. 

A developing storm will pull cold air into the high country of the Rockies. Highs today around Denver will be in the upper 80s but only in the upper 40s and falling through the day Friday. Two to six inches of snow are likely in much of the Denver and Boulder metro areas. With leaves on the trees, this situation might cause a lot of damage as the weight of the snow on leaves snaps branches and power lines. 

The mountains could see a foot or more of snow.

Meanwhile, parts of Iowa and Wisconsin are bracing for tornadoes today, one or two of which might be quite strong. And North Dakota is flooding again. 

I guess Vermont's weather variety show isn't as scary as that in other parts of the nation.