Sunday, June 30, 2024

Hurricane Beryl Stuns With Early Season Power

Satellite view of impressive Hurricane Beryl on
Sunday, the first Category 4 storm on record
to form in the Atlantic. 
 Hurricane Beryl, which I reported yesterday would get a lot stronger, really over-performed even those expectations. 

As of noon today, Beryl was a Category 4 powerhouse, with top sustained winds of 135 mph. Meteorologists and climatologists are stunned that a hurricane this early in the season would get so strong. 

It's easily the earliest Category 4 hurricane on record in the Atlantic Ocean. The previous record hold was Hurricane Dennis in the very busy year of 2005.

Hurricane Beryl does seem to be a harbinger of a very busy hurricane season. As I mentioned yesterday, Atlantic waters in many areas are at or near record warmth. Weather patterns are also expected to favor hurricanes this year. 

Although it's hard to tie specific weather events to climate change, Hurricane Beryl is definitely consistent with what to expect as the world warms. The oceans are getting warmer, making it easier for hurricanes to form and become stronger than they otherwise would be. 

Category 4's are almost always limited to the August into the first part of October. Category 4 hurricanes have winds of between 130 and 156 mph.

Even slightly weaker Category 3 storms, still regarded as major hurricanes are exceedingly rare in June. 

Per the Washington Post: 

"Before now, the Atlantic has only ever seen two major hurricanes during June - Audrey in 1957 and Alma in 1966. 'Major' hurricanes are this rated as Category 3 or higher. Both Audrey and Alma occurred in the Gulf of Mexico as early-season 'homegrown' storms. The Atlantic's Main Development Region, located between northern South America and Africa, was always believed to be inhospitable to major hurricanes during the month of June - until now."

Hurricane warnings are now up for Barbados, St. Lucia, St. Vincent and the Grenadine islands, Grenada and Tobago.

Beryl will probably slam those islands Monday, then head into the central Caribbean Sea.  Once it gets there, stronger upper level winds will start disrupting the hurricane's tall thunderstorms, making the overall hurricane slowly weaken.

It is still forecast to be a hurricane, though, by the time it approaches Mexico by the end of the week. Though Mexico is the most likely target, Beryl could veer north toward the Gulf of Mexico, or divert toward central America. 

Another disturbance Sunday along the coast of Mexico in the far southwestern Gulf of Mexico could turn into a tropical depression or storm later today before it moves ashore by tomorrow morning. Another disturbance way out in the central Atlantic that's roughly following the path of Beryl could become a tropical storm within a few days. 

 

Kind Of A Weird Severe Storm Threat In Vermont Today

By the looks of the sky this morning over St. Albans,
Vermont, you'd think we're starting a refreshingly
cool, dry, bright sunny Sunday. But the humidity
was oppressive when this photo was taken,
which could help set off strong storms between
now and at least early afternoon. 
 As expected, we had a bunch of rain yesterday and last evening and as we start our Sunday, the air out there in Vermont is like a wet blanket. 

It's super humid, but at least the wind died down.  The gusts to over 40 mph in the Champlain Valley and a few other spots led to a few power outages and a bit of tree and garden damage.

The sun is out in many spots in Vermont early this morning, too. That is actually a potentially bad thing.  

As a pre-frontal trough - which is sort of a mini-cold front ahead of a "real" cold front - comes in, the sun could work with this thing, helping destabilize the air to create a few severe thunderstorms. 

Usually, it takes until well into the afternoon for storms to really get going, and this pre-frontal trough will mostly be past Vermont by, say 1 p.m. or so.

So all, good, right?

But the air is so humid, at least near the surface, and atmospheric conditions are primed enough so that strong storms could get going very early. I'm writing this at 8 a.m. Sunday, and there's already a couple storms developing in the Adirondacks. As of 8:45 a.m. one of them was approaching the northern Champlain Valley, but at that point didn't look severe. At least not yet. 

These could intensify pretty fast and bring strong wind gusts and torrential downpours to a few places in Vermont by later this morning. 

The National Weather Service in South Burlington notes there's a layer of dry air high up above us. That would help limit the number of storms that form. 

The bottom line is that a few places could see some tree and power line damage this morning and early afternoon. Most places will be fine, but keep an eye to the skies. 

Also, in parts of northern Vermont, the soil is saturated.  The National Weather Service notes that the moderately heavy rain we saw yesterday and last night prompted quick rises along the Lamoille and Passumpsic rivers, and probably some smaller rivers and streams in northern Vermont. 

That's an indication that the soils can't hold much more rainfall. So, if any of these storms this morning or early afternoon are persistent, their torrential downpours could trigger a local flash flood. 

Not a guarantee, but something to watch. 

That pre-frontal trough, will head east and south into the rest of New England this afternoon and evening. There, the timing is such that those areas stand a better chance of severe storms that most of Vermont does. 

The activity back here in Vermont later this morning won't do all that much to ditch the high humidity, but it will help just a little. 

Meanwhile, the "real" cold front is lurking nearby. That will come through later this afternoon. The front could have its own batch of scattered shower and thunderstorms, but I strongly doubt there would be anything severe later on today. 

You'll notice the air changing this evening to something much more tolerable.

LOOKING AHEAD

As I mentioned yesterday, the weather systems over the past few days have been more energetic than usual for this time of year. They have been more like something you'd see in the spring, not summer.

Well, after this, summer is returning. In all respects. 

Weather fronts and storms will be weak, slow moving and erratic in the coming days, like they usually are in the summer. That will pretty much cut down on the drama, but of course, in the summer, if the conditions are right, you can alway get some strong storms or gullywashers.

So far, nothing particularly exciting is in the forecast for the next few days. 

You'll notice the temperatures will rise and so will the humidity after a comfortable Monday and sort of comfortable Tuesday.

We won't see extremely hot stuff like we dealt with in mid-June, but it will feel like summer. There will also be an almost ever-present threat of hit or miss showers and storms from Wednesday onward, but most of the time will be rain-free. 

At this point, it looks like the best chances of rain come Wedneday night, when a failing cold front arrives and pretty much passes out dead overhead. It could cause some local downpours, but nothing terrible.

The relative lack of rain in the upcoming week is mostly good. But it depends where you are in Vermont.

Much of northern Vermont needs to dry out some so we don't have a repeat of last summer's flood hell. On the other hand, parts of the southern half of Vermont could stand to see more rain. 

Any rain that does fall in the upcoming week, unfortunately is most likely in the northern half of the state. 

Saturday, June 29, 2024

Soon To Be Weird, Early Season Hurricane Beryl Menaces Caribbean

Satellite view of a healthy looking Tropical Storm
Beryl early this afternoon has "that look" that suggests
it could turn into a powerful and 
dangerous early season hurricane. 
 Tropical Storm Beryl was gathering steam pretty quickly Saturday out in the open Atlantic. It's behavior seems to hint at the widely predicted very busy Atlantic hurricane season for 2024.  

As of late Saturday morning, Beryl had top winds of 65 mph as it headed toward the Windward Islands. Barbados is already under a hurricane watch, as Beryl should be near that island late Sunday or early Monday. 

Tropical storms and hurricanes absolutely adore very warm ocean water and Beryl is no exception.  The hotter the water, the better chance a storm like this will strengthen.  That's one of the reasons why forecasters were saying this will be a busy hurricane season.

Waters in most of the areas where hurricanes form are at near record high levels.

Those super warm waters make Beryl weird and very much an early bird.  It's developing in an area where hurricanes very often get their act together. But this hurricane incubator zone pretty much never produces tropical storms until late August or September.

That Beryl is forming there is a testament to how unusually hot the water is out there.

Philip Klotzbach, a meteorologist who specializes in Atlantic hurricanes said Saturday Beryl is the strongest tropical storm on record to develop that far east in the Atlantic Ocean.

Normally, if you do manage to get a hurricane in late June or early July, it forms in the Gulf of Mexico, or even further south, near Mexico's Bay of Campeche. 

The hot water under Beryl means it will probably strengthen rapidly on its trek toward the Windward Islands. By the time it gets to near Barbados, its top sustained winds could reach or exceed 110 mph.  Such rapid intensification in this part of the Atlantic is pretty much unheard of early in the season is unheard of.

Once Beryl gets into the Caribbean next week, it's future strength and track are still open to question. Stronger upper level winds could slowly weaken it. We also don't know whether this will eventually threaten the United States or not. 

Meanwhile, there's other areas the National Hurricane Center is watching. Another disturbance in the eastern Atlantic is following roughly the same path as Beryl and could develop into a new tropical storm next week. 

A disturbance near the Gulf of Coast of northeastern Mexico could briefly develop into a tropical storm before it runs inland next week. 

Overall, this whole scenario in the tropical storm and hurricane zone in the Atlantic reminds me of how things usually look when the season usually is ramping up in mid-August.  It's usually pretty quiet in late June. 

This is an ominous sign that all those forecasts of a very busy and potentially destructive Atlantic hurricane season of 2024 might well come true. 


 

Little Change In Stormy Vermont Weekend Outlook: Wind, Rain, Thunder

A gusty overcast early Saturday morning out on my
St. Albans, Vermont weather deck introduces 
another rather stormy weekend in the Green Mountain State.
 After a gorgeous Friday surely endorsed by the Vermont Department of Tourism and Marketing, we're stuck in kind of a stormy weekend.  

Now, we get the not so nice weather. Overall, the forecast hasn't changed much since yesterday. Here's the rundown

SATURDAY

The storm system causing this and its warm and cold fronts are more typical of the type of thing we get in the spring, not summer, so the forces driving the weather are stronger than you'd expect in the summer. 

Summer patterns are pretty laggard and slow. Spring weather patterns tend to be more vibrant and changeable.

So it is with this one. The departing high pressure system that gave us our nice Friday and the storm causing all the bad weather in Canada are both strong for this time of year.

Which means the wind between the two is strong. It was already gusty in the Champlain Valley early this morning, and it will be a windy day across most of Vermont.

Lake Champlain and the surrounding valley will be windiest, with gusts over 40 mph. We could see wave heights go as high as four feet on the lake, so today is not the time for a nice excursion out here in a small boat or kayak. 

Even though showers had already arrived in parts of Vermont by dawn, it wasn't really humid out there. That will change fast as those south winds drive muggy air northward. 

The dew point, a measure of how humid it feels out there, were in the comfortable 50s this morning and will end up close to the awful upper 60s by late afternoon and evening. 

The increasing humidity will change the character of the showers, too. They'll go from widespread and fairly light during much of the day to perhaps more patchy and locally  heavier tonight. 

Though patchy, there should be lots of showers and possible storms around tonight. That brings in the risk of locally heavy rain. 

There's still a low, but not zero chance of local flash flooding overnight. Especially in the Adirondacks and in the mountains of central Vermont. The vast majority of us, though, will not have enough rain to cause any worries. 

The pre-dawn hours aren't usually the hour for strong storms, but one or two storms in this set up could be relatively gusty and accompanied by lightning and real gullywashers before sunup. Most of us won't see anything like that but a few of us might.

SUNDAY

The humidity will be awful when you get up tomorrow, but don't worry it won't last too long. A cold front will clear out the yuck toward evening.

As is usual, most thunderstorms with the front will actually focus a little ahead of it. Thunderstorms ahead of a cold front usually reach their peak intensity when the sun's heating is strongest, in the afternoon and evening. 

There's a marginal chance (dark green) of a couple 
severe storms in Vermont Sunday, but a 
better chance further east (in yellow).

The cold front timing is such that in Vermont, the best chance of storms is late morning and midday -m before they can get to their top strength. Still, a couple of them might be severe as they simultaneously move eastward through the state and get more intense.

A storm with damaging wind gusts could form anywhere in Vermont, but they probably will be few and far between in the northwest. The southeastern part of the state has a better chance of seeing severe storms. 

There were tornadoes reported in New England last Sunday and again Wednesday night in New England. We might do it again this Sunday, as there's a non-zero chance of a spinup in much of the region.

In Vermont, the chances are of a tornado look pretty much zero at this point, except perhaps in the far southeastern tip of the state. The best chances are further east. 

The cold front itself should move through later in the afternoon with its own batch of scattered showers and non-severe thunderstorms. 

Another burst of refreshing air should be in place by Monday before it starts to turn somewhat humid again during the week.  

Friday, June 28, 2024

This Won't Be A Great Summer Weather Weekend in Vermont. Some Flood/Storm Worries, Too

Cool air and gusty winds last evening felt autumnal
Thursday evening. That will lead to another 
stormy weekend in Vermont, with some local
flash flood risks in the area.
 Thursday evening around my house had an autumnal feel, sorry to say for you summer lovers.

It was so much like a September late afternoon or evening. Cool gusty west winds tossed the trees under a ceiling of broken clouds. The air felt crisp and dry. I almost felt like I should start buttoning up the garden to close the season.  

This morning felt like fall, too, with temperatures for  most of us in the 40s. Cold spots in the Northeast Kingdom were in the 30s, and perennial icebox Saranac Lake, New York had another summer frost, getting down to at least 32 degrees. 

The reality, of course, is autumn is a long way off.  The season has just started and we have tons of summer to get through. 

Many of you are probably itching to get out and enjoy summer this weekend, but buyer beware: This won't be the ultimate summer fun weather weekend. But at least we're having Chamber of Commerce weather across Vermont today, so that's good. 

This Saturday and Sunday are going to kind of mirror last weekend,  which definitely proved stormy. There will be some differences, of course. The timing of some cold fronts Sunday might save us from the worst of the severe weather that will hit the Northeast once again over the weekend. 

However, we do have some risks to talk about here in Vermont. That amid the generally bad weather we expect Saturday and Sunday. 

SATURDAY

Expect clouds and in some places wind and fairly cool temperatures for your Saturday. Even though temperatures won't get that warm, you'll find the humidity during the day rising amid some south winds.

Saturday will not be your day to take the boat out on Lake Champlain. There, winds should gust over 40 mph, especially before the bulk of the expected rains move in later in the afternoon. Waves at times could built to as much as three to five feet. 

On shore, winds could also gust over 40 mph in the central and  northern Champlain Valley, which could be enough to create some isolated power outages.

The rain could come down hard at times in some spots overnight Saturday into the early morning hours of Sunday. This could begin to unfortunately touch off some local flash floods. That's especially true in the northern Adirondacks, where the best chances of the heaviest rain are, and in central Vermont, where flash flooding and torrential rains last weekend have really soaked the ground. 

Although we're in for some areas of heavy rain, severe thunderstorms should stay to our west Saturday night. 

SUNDAY

When you wake up Sunday morning, you'll find it wet and quite humid again. The first of a couple cold fronts will be on our doorstep. Knock on wood it will come through early enough in the day so that severe thunderstorms will focus mostly just to our east. 

That is not set in stone yet, but that's the way it's beginning to look. Stay tuned for updates. 

With all that humidity around, however, we do risk some torrential downpours, so once again - sigh - we'll have to watch for the risk of flash flooding. It'll be localized as only a few places will get the heaviest rain.  Most of us should see at least some rain, though. 

Overall, the National Weather Service in South Burlington says most of us should see storm totals of about three quarters of an inch to 1.5 inches. But some unlucky places could get two or three inches or even a little bit more, so that's why meteorologists are keeping an eye of the flood risk. 

The area of north central Vermont, including Stowe, Worcester, Elmore  and that area will need to be watched again as they are still recovering from last Sunday's flash flooding. 

There's no guarantee we'll see any renewed flooding, it's just a possibility. Considering how often parts of Vermont have suffered flood damage in recent years, we don't need this again. 

After Sunday's weather, we'll have another spell of cool, dry conditions, though not as chilly as it was yesterday and last night. After that, signs point toward humidity creeping up again as we approach the Fourth of July. 

Thursday, June 27, 2024

Sunday's Vermont Flash Floods Repeat A Disturbing, Worsening Pattern

A big gush of rain over Lake Champlain last summer.
Climate change is helping to make summer downpours
heavier. Local flash floods, like what happened Sunday
in central Vermont, are unfortunately getting more common
The flash flooding that hit parts of north-central Vermont last Sunday certainly weren't as bad as last summer's catastrophic summer flooding, but it still stung, big time. 

Especially since it keeps happening over and over again.

It seems like mountain towns barely clean up from the washed out roads, slopes and culverts from flash floods when the next one hits. 

Climate change has increased the likelihood that our normal summer cloudbursts become not so normal, and instead, especially have and destructive. 

 "It's a bit scary at this point how often we have to put Humpty Dumpty back together again," Stowe Director of Public Works told WPTZ. "I've been Stowe's public works director for 14 years, and this is the seventh event that would exceed a 100-year storm." 

Sunday's storm dumped at least two inches of rain on Stowe in just 30 minutes. There's no way you can contain the runoff from that, especially considering there had been downpours earlier in the afternoon. 

There was a report that the rainfall rate in Jericho during one storm reached 6.25 inches per hour. Obviously, that was just a few minutes of the storm and the town didn't actually accumulate that much rain. 

 The flooding Sunday was not limited to Stowe.  Video on Facebook showed a raging brook overwhelming a road in Worcester. Several roads in that town had to be closed because of flood damage.

Last summer's catastrophic floods understandably captured most of the attention, but its these local floods that hit Stowe, Worcester and Elmore Sunday that will be the most common in our climate changed, wetter world. 

Vermont's geography makes the region prone to flash floods. If torrential rains hits a mountainous area, the water rushes down the steep slopes, and often carries mud, rocks and branches with it. Just a couple inches of rain in an hour can unleash some real damage. 

The distressing thing is the flash floods are happening frequently enough now, you never know which of our many summer downpours will turn destructive. I'm sure public works crews and many others in Vermont brace themselves when they hear of a heavy rain risk. 

There's always close misses, too.  Flash flooding was reported in southern New England last night from a storm whose punch luckily passed south of Vermont. There's also a very low, but not zero chance of flash flooding in Vermont Saturday night. (Though so far I'm not especially worried about that one, stay tuned).

Like many other places around the nation and world, Vermont is trying to build resilience to these repeated disasters with bigger, stronger culverts and such. But as Sunday's storm in Stowe demonstrates, there's only so much you can do.

Expect many more rounds of flash flood damage in Vermont in the coming years, especially in the summers.  

Wednesday, June 26, 2024

May Was Yet World's 12th Consecutive Record Hottest Month; June Could Do It Again

Lots of red in the world temperature map for May 
Shades of red represent warmer than average areas
and the darkest red is record warmest in those locations.
 Catching up with climate statistics I had to note that climatologists think June could well be the warmest on record.  

This might be even more surprising than May's global performance as the world's 12th consecutive hottest month.

May beat the previous record set in 2020 by about a third of a degree Fahrenheit. That doesn't sound like much at all, but when you compile all the world's data, that amounts to a huge margin above the previous record level.

El Nino teamed up with climate change to boost global temperature to new heights.  El Nino heats up the eastern Pacific Ocean, and tends to make the world's overall temperature a little warmer. 

El Nino has been crashing fast, to be replaced by La Nina, which tends to cool the world's atmosphere just a little. 

So far, we haven't seen that.  There's usually a lag in which the subtle La Nina cooling begins. Climatologists are starting to tap their feet and check their watches nervously as that hasn't happened yet. 

The scientists for now are still convinced months during the second half of 2024 won't keep breaking monthly records for the world. But there's no question the heat is on forever, even if some months "only" score in the top 10 warmest.

With La Nina in the picture, there's "only" a 50/50 shot at 2024 becoming the world's hottest year on record, besting 2023, according to the National Centers for Environmental Information.

We won't know until we get into July whether the current month ended up breaking the record for hottest June, obviously set just last year.

But we know May solidly broke the world record. Almost nobody on the planet had a cool May. The only pockets of "chill",  at least relative to the heat of recent years. Southern South America, western Russia, a few pockets in Antarctica, a couple areas of Greenland and a small dot in the western United States were a little on the cool side. 

If you are under the age of 48, you've never seen a May in which the overall world temperature was even a teeny, tiny bit cooler than the long term average. 

By the way, as May was the 12th consecutive record hot month, the oceans had their 14th consecutive record hot water month in May. 

With each month through May at record levels, the world as a whole had its warmest January-May stretch on record. 

The United States had its 13th warmest May out of the past 130 years.

Florida had its warmest May on record. Thirteen other states, including Vermont had one of their top 10 warmest Mays in 2024,

 

Eastern U.S. Seems To Be Latest Severe Weather Target, Vermont Catching A Break

The weather pattern favors occasional bouts of severe
thunderstorms in the Northeast over the next week or 
more. However, Vermont will be on the sidelines
of today's outbreak, and also possibly again
with new storms over the weekend. 
 As we all know, there's been a ton of severe weather, tornadoes and flooding hitting the U.S. repeatedly since April.  

The storm train continues, and it seems the eastern United States is most under the gun at the moment.   On Sunday, we had those tornado watches, severe thunderstorms and flash flooding in the Northeast, including a confirmed tornado in Dublin, New Hampshire. 

The northern tier of the United States is now under a fast jet stream, at least by summer standards, and that means lots of opportunities for severe weather. 

The seemingly ever-present heat dome in the south and Midwest keeps trying to send hot air up into the Northeast, but the cold fronts keep cutting it off at the pass. Especially the further north you go.

The cold fronts, encountering those attempts at hot, humid air, create the ingredients for severe weather. That's what happened Sunday.

Although Vermont got hit over the weekend, we do seem to be catching a break this week. Severe thunderstorms are in the cards today for a broad area extending from Kentucky and Ohio to near New York City.

Strong straight line winds and local flash floods will be the end result. Far southern Vermont might catch an isolated strong storm, but in general, Vermont will sit this one out. 

The Green Mountain State did manage to get some showers overnight and this morning. More showers are due tonight. But I don't see anything scary in this forecast. 

The next wave of potentially severe weather comes to the East Saturday and Sunday. It's still too early to know the extent and exact location of any severe storms this weekend, but it looks inevitable somewhere in the Mid-Atlantic or Northeast.

That also means it's too soon to tell if Vermont will participate in this, but early betting suggests we might once again avoid the worst of it. 

This regime of storm threats once every two or three days is actually fairly common in the summer.  It usually takes some activity from the jet stream to help encourage stormy weather. 

The jet stream usually retreats to southern Canada in the summer, but the Northeast is sometimes close enough to the jet stream to have some strong thunderstorms spin off. Especially if heat and humidity lurks just to the south to add fuel, as is going on now. 

As we head into July, who knows, but best early guesses is this up and down temperature yoyo between refreshing days and muggy ones will continue, and those storm risks will probably come through with every transition. 

Tuesday, June 25, 2024

Midwest Flooding Has Been Quite Scary, Probably Worst Since 1993

Interstate 29 in southeastern South Dakota looks like
an immense lake after torrential rains caused 
catastrophic flooding in the region. 
 The flooding in South Dakota, Iowa and Minnesota this month has been scary to say the least, as a summer of storms have unleashed havoc in the region.   

This is far worse than the usual torrential thunderstorms and local flash floods fairly common in the Midwest each summer.

You might have seen the horrible images of collapsing houses, whole solid little Midwestern towns under water, so many square miles of cropland drowned. 

At first, it was the smaller creeks and rivers that caused all the destruction. The high water has now moved into bigger rivers. Even the mighty Missouri and even mightier Mississippi are now flooding. And that flooding is forecast to get worse.

Per the Washington Post: 

"As of Monday, rivers across the Missouri River basin were at major flood stage: The James, Vermillion and Big Sioux rivers in South Dakota and the Des Moines and Little Sioux rivers in southwestern Minnesota and northwestern Iowa, according to National Oceanic and Atmospheric Administration data."

This flood hits me more in the gut than usual because I have relatives in eastern South Dakota and in Minnesota.

Luckily, their towns, like Yankton, South Dakota, have so far avoided the worst of the flooding, though the James River nearby Yankton is cresting at major flood stage. 

The torrential downpours have tapered off for now, but the damage is not done done. A whopping ten to 18 inches of rain fell on chunks of the Missouri and upper Mississippi River basins last week.  No wonder the flooding is still getting worse.   

Examples of extreme damage are everywhere.

As of Tuesday, several major highways remained closed by flooding, including Interstate 29 in southeastern South Dakota. In that area, McCook Lake and the Big Sioux River combined to wash at least two houses away. Many more were damaged or destroyed, and severely undermined by rushing water. 

In Iowa, at least, 1,900 homes have been damaged or destroyed by the flooding.  Part of a railroad bridge collapsed into the floodwaters at North Sioux City, Iowa. In some of the most widely reported and viewed flood news, water detoured around a dam in Mankato, Minnesota, threatening worse flooding. The dam itself was still holding as of Tuesday. 

 The flooding hit because South Dakota, Iowa and Minnesota were on the northern edge of the big heat dome that caused record high temperatures from Texas to the East Coast. The northern edge of a heat dome like this is known as the "ring of fire" because torrential rains and thunderstorms often ride that edge of the heat. 

This is consistent with climate change, too. A warmer atmosphere can contain more moisture. Storms can grab that extra moisture and dump it as torrential, flood-producing downpours. I don't know to what extent climate change had to do with this Midwest disaster, but the potential fingerprints are there.

The rainfall over the next few days in the flood zone looks milder than it's been, but still enough to potential cause issues. Rainfall in Iowa could amount to up to two inches over the next seven days.  

Some of that expected rain is likely to come down as pretty intense downpours, increasing the chance of local floods as those gullywashers hit already soaked ground. 

Even with the relative lack of downpours, the flooding in the larger rivers could last well into July.  

While Nation Bakes And Floods, We Will Stay On The Cool Side Here In Vermont. Mostly, Anyway

Now that the oppressive heat and the threat of dangerous
thunderstorms is gone in Vermont in favor of generally'
nice weather, our "outdoor living room" in 
St. Albans, Vermont is ready for our enjoyment. 
 After that heat wave earlier this month and a very humid weekend, we're now in a regime where we watch everybody else bake from the sidelines.  

While we were dealing with severe thunderstorms Sunday, the heat lingered along the East Coast.  Over the weekend, Baltimore reached 101 degrees. Washington DC was close behind at 100.

That heat waned on Monday at least to an extent. But a brief new surge of heat is coming up the coast today and tomorrow, but will get cut off at the pass but cold fronts before it can really plow into northern New England. 

After that, the intense heat will shift to the middle of the nation and the Southeast where the infamous heat dome will set up residence for awhile.  I'd say at least a quarter of the nation would be in the dangerous heat zone during this time.

Meanwhile, vicious storms keep hitting the Upper Midwest with high winds and especially flooding. 

For us up here in Vermont, expect generally a nice refreshing break from steamy summer weather, at least on most days for the next week or more.

Today and Wednesday will be warm with a fair amount of sun, but not ridiculously so with highs in the upper 70s to mid 80s, depending on where you are.

The only real risk we need to watch for is locally heavy rains Wednesday night. We had some flash flooding in sections of northern Vermont Sunday, so this area in particular is sensitive to more downpours. The risk of renewed flooding Wednesday night is low, but not zero. 

The cold fronts Wednesday night will bring us delightfully cool and dry and sunny weather tentatively scheduled to begin Thursday afternoon and going well into Friday, when temperatures will only make it into 70s.

Another squirt of humid weather looks like it will try to make a run at us Saturday before more friendly (and smoke-free!) cold fronts blow through New England by Sunday..

As is pretty much always the case, I'm getting mixed messages from long range forecasts going through Fourth of July week, but the odds of more cold fronts to keep the heat at bay look at least not bad heading into July.

Time will tell whether I'm proven right or not. 

With every cold front passage this time of year, you have to look at the possibility of severe storms, but you don't know whether there's much of a risk until at least a couple days before these otherwise friendly cold fronts hit.  

The weather fronts later Wednesday and Wednesday look pretty safe for us, as severe weather looks like it'll pass by mostly to our south.  We'll get some rain out of it, and maybe some garden style thunder, but nothing really excessive. 

It's a little soon to think about any severe weather with Saturday's fronts, or any that come through after that. 

For now anyway, in a summer of extreme weather, and after a tangle with dangerous heat and dangerous thunderstorms, Vermont has re-entered the safe zone.  At least for awhile.   

Monday, June 24, 2024

Plenty Of Tree Damage, Flash Flooding In Wake Of Vermont Tornado-Warned Storms. Did Any Touch Down?

For what it's worth, interesting wind shift Sunday in
a tornado-warned storm in the southern end of 
Hinesburg, Vermont. Here, screen grab at 2:12
pm, judging by tilt of the tree, wind is 
coming in from the southwest. ....
As expected, Sunday turned out to be a wild day in parts of Vermont, with tornado, severe thunderstorm and flash flood warnings flying.   

Most of the state got through Sunday with no trouble at all. It seems like the middle of the Green Mountain State took the brunt of the weather.  

While there was definitely wind damage, some of the biggest trouble Sunday stemmed from flash flooding. 

Sunday's two most intense storms - both of which carried tornado warnings -  hit pretty much the same areas in central Vermont, touching off tree damage, power outages and flash flooding 

Here's what I saw. 

STORM #1

The National Weather Service in South Burlington at 2:07 p.m. Sunday issued a tornado warning. for an area around Monkton, Starksboro and Huntington, and extended the tornado warning to areas around Waterbury, Waitsfield and Montpelier at 2:28 p.m.

...... Second screen grab, from just one minute later at
2:13 p.m. shows more intense wind and rain with
the wind now coming out of the east to southeast. This
is north of where the storm rotation was, but it's possible
that rotation influenced wind direction away from it.
There was one area of Monkton where trees were reported down.  I was in the southern end of Hinesburg at the time, an area covered by the tornado warning. 

I definitely did not see a tornado, as I was a little bit north of where the storm rotation was. But the area I was in at the Cedar Knoll Country Club experienced gusty west winds, followed quickly by even stronger southeast winds and torrential rains. 

That was potentially influenced by some sort of circulation a little to the south of me, or it could have been simply the orientation of downbursts. 

After the storm I traveled down Route 116 through Starksboro where if a tornado existed it would have crossed. At that particular point along Route 116 the only damage I saw was a few branches down and some minor flash flooding. 

STORM #2

Later in the afternoon, a fairly unimpressive looking storm in eastern New York intensified as it splashed ashore on the Vermont side of Lake Champlain.   

It developed torrential rains and gusty winds where I was in South Burlington and Shelburne around 4 p.m., then intensified further as it moved east. At 4:07 and 4:12 p.m., the National Weather Service issued a pair of severe thunderstorm warnings for a zone extending from central Chittenden County all the way to areas around Morrisville, Waterbury, Worcester, Montpelier and Johnson. 

That severe thunderstorm warning in a broad area around Waterbury was renewed at 4:43 p.m. Meteorologists at this point must have been beginning to see signs of rotation because they added the following sentences to this new severe storm warning: "Remain alert for a possible tornado! Tornadoes can develop quickly from severe thunderstorms." 

At 4:51 p.m., a tornado warning was issued for an area in and around Waterbury. Around that time, numerous trees were reported uprooted or snapped off at Little River State Park in Waterbury, which was in the middle of the tornado warning zone.  

 From what I can tell, the damage patterns reported didn't warrant the National Weather Service going out for a look see. So for now, we can conclude we had rotation, but no actual tornadoes with this episode.  Close but no cigar. Though if something changes, I'll update you.

FLASH FLOODING

Those two intense storms hit roughly the same areas. Both storms contained ferocious downpours. There were quite a few damage reports. I saw some flash flooding on French Hill in Williston, and it goes worse as the storms reached peak intensity further east. 

Torrential rains touched off some flash flooding on a very
flood prone spot on Williston Road in South Burlington.
As the storm moved east, it causes much worse
flash flooding in the Green Mountains especially
near Stowe, Worcester and Elmore 

Parts of the Bolton access road were damage, as was Route 100 between Waterbury and Stowe.  Part of Route 12 in Worcester was closed. 

Part of Route 14 in Hardwick was also shut down due to high water. A bridge washed out on Elmore Mountain Road, and other road damage was seen around Elmore and Worcester. 

In Stowe, Stowe Hollow, North Hollow, Moss Glen Falls roads and others in town were damaged and in many cases impassable.  

Damage from flooding in Vermont Sunday was definitely worse than wind or potential tornado damage.

OUTLOOK

Much calmer today in Vermont. Today was cloudy and showery across much of Vermont, though some afternoon sun broke out in the northwest. It's been a refreshingly cool one after all the humidity we've had lately.   

After a bright and much warmer Tuesday, the next chance of severe weather comes with some weather fronts Wednesday. The prospect for bad storms Wednesday is still really iffy, and so far, trends have been moving away from a severe risk, so fingers crossed!  

Sunday, June 23, 2024

Quick Sunday Evening Update: Worst Is Over Northern Vermont; Unsure Yet If Any Tornadoes Developed

Intense wind and rain today in the southern part of
Hinesburg today, a short distance north of where
rotation was detected in a storm, prompting a 
tornado warning 
 Turn out the worst of today's storms focused their attention on central Vermont, where the National Weather Service office in South Burlington today had to issue two tornado warnings, several severe storm warnings and a flash flood warning. 

The first rotating storm blew through Charlotte, Ferrisburgh and Monkton before continuing on into the central Green Mountains at and beyond Buels Gore.

A wide funnel cloud was photographed near Monkton, and numerous trees were reported down in the area. But it's unclear whether a tornado touched down. I might have more info on that tomorrow.

I was just north of that circulation in the southern end of Hinesburg and encountered heavy rain with a gusty west wind that quickly turned into an even stronger southeast wind, which made me wonder if some sort of circulation was nearby.

A second storm, that was merely strong in New York state and over Lake Champlain later in the afternoon, turned into a severe thunderstorm that eventually developed enough rotation to require another tornado warning around Waterbury and just north of Montpelier around 5 p.m. 

I also don't know the outcome of that. The same storm, and the one before it dumped torrential rains that prompted flash flooding around Mount Mansfield.

THIS EVENING AND BEYOND

I think northern and central Vermont is now pretty much out of the woods. More storms could develop in New York and become strong, but I don't think they will be particularly severe, never mind tornadic.

As of 6 p.m., there were still some intense storms in New York between Glens Falls and Albany that could cause some problems in the next few hours south of Route 4. 

Torrential rain in thunderstorms put a flood-prone
section of Williston Road in South Burlington under water.

Flash flooding has caused a fair amount of damage in north central Vermont, especially around Elmore. Expect some high water and washouts to continue there for awhile as the runoff from the heavy rains drains away. 

Looking ahead, we could have numerous showers and a few garden variety thunderstorms Monday, but nothing severe. Also, the rain shouldn't be enough to cause any more flooding problems.

Going further into the week, the next chance of severe weather will come Wednesday, but that's iffy, and a lot of forecast updates need to come through before we say anything definitive about that. 

I'll have a full update on today's storms and what's next in tomorrow morning's post.  

Early Afternoon Vermont Severe Risk Update: Storms Beginning To Fire, Tornado, Damaging Wind Risk Continues

National Weather Service radar at 12:30 p.m. today showed
storms just beginning to fire up in New York. Those storms
will rapidly intensify and expand as they head into
Vermont with damaging wind and even tornado risks. 
Storms were just beginning to fire up as of 12:30 p.m. today as we brace for a rare combo, for Vermont anyway, of intense thunderstorms and a real risk of a few tornadoes. 

NOAA's Storm Prediction Center said they would very likely issue a tornado watch for probably all of Vermont, almost all of New Hampshire  eastern New York and northern Massachusetts. We don't get too many tornado watches around here, so that's something to note. 

By the time you read this, we'll very probably be under that tornado watch. 

It does feel like tornado weather out there. At my place in St. Albans, we have fairly strong, gusty south winds and a lot of humidity.

The storms were initiating in central New York.  They hadn't developed in Vermont yet, but both the growing New York storms and new storms in the Green  Mountain State should get going soon.

You'll really need to stay on your toes today. The storms are and will be moving forward pretty fast. So there might not be much lead time between when the National Weather Service issues a tornado or severe thunderstorm warning and when the storm actually hits. 

If it's tornado warning, head to the basement pronto. If it's a severe thunderstorm warning, do the same, or at least stay away from the windows. 

It's still impossible to say who gets the worst storms around here. It'll be kind of random. The risk is statewide. And in adjacent states.  As always, it will be a matter of one town getting blasted by wind damage while the next town over is perfectly fine. 

NOAA's Storm Prediction Center still has the highest chances of tornadoes in central and southern Vermont, but again, they could pop up anywhere. 

Clouds have generally won out over sunshine late this morning and early afternoon. That might ever so slightly diminish the risk, but certainly not get rid of it. 

As the National Weather Service office in South Burlington said in a special weather statement issued a little before noon, we have a rare combination of high humidity, wind shear and forcing. 

By wind shear, they mean the wind is changing in direction and speed with height, which helps storms rotate and potentially generate a tornado. By forcing, they mean the atmosphere is primed to support tall, rapidly growing storms that can turn severe super fast.  

A disturbance called a pre-frontal trough is heading our way from New York this afternoon, which would further enhance storms. Also, a weak boundary extending down the Connecticut River Valley might add to the spin in the atmosphere, says NOAA's Storm Prediction Center, which might concentrate the tornado risk there. But again, that problem could occur anywhere in Vermont and surrounding areas. 

 The National Weather Service, in their special weather statement, went as far to suggest that people who live in mobile homes consider if possible relocating to more sturdy buildings this afternoon and evening. 

Pay attention to the weather, and warnings from now into the evening. The peak of this mess will probably come mid afternoon, but there could well be trouble before and after that. 

Stay safe, but don't panic. We don't mean to scare you because obviously if there are any tornadoes, they'll affect a tiny percentage of us. The damaging winds won't affect everybody either. But you never know in advance what will happen. Take all weather warnings today seriously, and make sure you have multiple ways to receive them. 

Vermont Storm And Tornado Risk Is On For Today. What To Know

Here's a map you don't see every day. It's from NOAA's
Storm Prediction Center and has easily the nation's
most significant tornado risk centered over Vermont. 
You're going to want to be weather aware in Vermont, most of the rest of New England, much of New York and southern Quebec today, as danger lurks. 

The already well-advertised danger includes the high likelihood of severe thunderstorms and one of the highest tornado risks I've ever seen in Vermont. 

That's not to say the whole state will be leveled by twisters or even damaging thunderstorms winds. 

Not even close. But somebody is going to suffer the loss of trees, power lines, and possibly even roofs or weaker structures in the worst storms. 

There's no guarantee there will be a tornado in Vermont, but the chances are decent that at least a brief one might form if any supercell storms can get going without too much interference from neighboring storms 

Even if there's no tornadoes today, it's a day to keep watch.

HOW IT PLAYS OUT

The warm front which was sort of hung up in far southern Vermont yesterday was finally on the move north this morning.

It was unleashing lots of showers, with embedded heavy downpours and rumbles of thunder. I'm not at all worried about this early morning stuff. We won't have any severe storms with it. 

The warm front will - as long expected - stall out somewhere in southern Quebec.  You might get a false sense of security later this morning as the rain stops and the sun tries to break through. 

But that brighter but humid break in the weather helps set the stage for today's wild weather.  Storms will start to fire up by early afternoon, probably mostly in eastern New York then spreading into Vermont. 

If there's a lot of sun before this happens, that'll make things even worse as the sun's heat will increase instability. But even if we don't get much sun, the atmosphere is primed for severe weather. As of 8 a.m., I do see a fair amount of cleaning skies in central New York, heading our way. 

I don't think it's a question of if we'll see severe thunderstorms somewhere in Vermont today. It's only a matter of whether they'll be few and far between, or we get a ton of them, or something in the middle of that. 

That stalled warm front will help to veer the winds in the atmosphere, which could make some storms turn into rotating supercells.

There will probably actually be two types of storms around. One of them is those rotating supercells. They'll be somewhat isolated from one another and carry the risk of destructive winds, large hail and of course perhaps a tornado.

The other storms will be clusters or relatively short lines of storm, which will really be as dangerous as the supercells. The storm clusters are less likely to produce any spin ups, but they can contain very damaging straight line winds. 

As of very early this morning, NOAA's Storm Prediction Center was still placing the best chances of a tornado in Vermont along and south of a line from Rutland to St. Johnsbury. Note that a tornado could also spin up anywhere else in the Green Mountain State.

Another map from the Storm Prediction Center this morning centers the greatest risk for tornadoes over central and northern Vermont except for the extreme Northeast Kingdom. 

The higher risk of tornadoes also extends through most of New Hampshire and western Massachusetts. 

This general forecast will get updated later this morning.

By the way, don't count on the Green Mountains to disrupt a wannabe tornado. That could happen, but then again, if the conditions are right, they're known to climb up and down hills. 

The threat from the big storms today will wane in the evening

WHAT TO DO

First of all, there's no need to panic over this. We're not used to tornado risk days, but they do happen occasionally.

All day today, try to stick to an area where you can quickly get into a sturdy building if a storm approaches. Today is NOT the day for a boat ride on Lake Champlain, or a nice hike in the Green Mountains. 

You might want to secure loose stuff like lawn furniture this morning and charge your devices, since I expect power outages. 

Always have with you a way to receive warnings. More than one source is best. If you have a weather radio, have that with you. Also tune into reliable sources of weather information, like the National Weather Service or our fine television meteorologists in the area.

Those meteorologists will probably cut into regular program if the tornado or very severe storm threat arises.

If you get a tornado warning, immediately grab your kids and pets and head to the basement. If you don't have a basement, try to get into a windowless place in the middle of the house or building you're in.  It doesn't hurt to put on sturdy shoes and a bicycle or motorcycle helmet for added protection.

Whatever you do, don't look for the tornado to see if it's really there and approaching. Chances are if it's there, it's hidden by trees or thick curtains of rain. New England tornadoes are often wrapped up in rain, and you don't see that familiar funnel shaped cloud common out in the Plains. 

Some of today's severe storms, even if they don't include tornadoes, will be stronger than the usual gusty ones we see in the summer.  If you receive a severe thunderstorm warning, it's still not a bad idea   to get in the basement, as if it were a tornado.  At the very least, stay away from the windows and be in a sturdy building. 

There's probably going to be a lot of cloud to ground lightning with these storms, so be careful with that.  There's the risk of localized flash flooding if the downpours are intense. That could be especially true near the Canadian border, where the heaviest rain from the warm front probably fell this morning.  

After the storm, look out for live wires.  If there's debris, be careful around that. Maybe wear work boots, too, since there could be sharp objects like nails and such in the mess. If you need to use a chain saw to clear fallen branches and trees, be careful, know what you're doing and don't be under the influence. 

Definitely stay out of any houses or buildings that have a lot of damage, say if a large tree fell on it or something like that. 

Many storm injuries aren't caused by the storm itself, but injuries during the cleanup after it. 

To the best of my knowledge, nobody has ever died in a tornado in Vermont. I sincerely doubt will end that great record today, but we still want to be alert to any dangers coming our way today. 


Saturday, June 22, 2024

Quick Vermont/New England Storm Update: Still A Worrisome Forecast For Sunday

That yellow shading depicting tornado risk is
relatively common in the Midwest during the
spring and early summer, but quite
rare in New England. Rough weather
still expected Sunday. 
I should offer a quick Saturday evening update on the severe weather we expect in Vermont and New England tomorrow, so here we go. 

If anything, forecasters have gotten even a little more confident of severe, dangerous thunderstorms and even maybe a few tornadoes in Vermont, along with eastern New York, most of the rest of New England and far southern Quebec on Sunday. 

NOAA's Storm Prediction Center has issues a rare 10 percent area for tornado risk in a good section of New England. That means there's a 10 percent chance that a tornado would touch down within 25 miles of that area. 

That sounds small, but it's pretty typical of a Midwestern style tornado outbreak. 

That 10 percent area is mostly in the southern half of Vermont and southwestern New Hampshire, but we shouldn't  really focus on that. 

There is at least a small chance of a tornado, and a greater chance of dangerous thunderstorms pretty much everywhere in New England except northeastern Maine. 

It already seems like this storm has a propensity to cause mischief.  It has caused severe flooding in South Dakota and Iowa.

It also has already started to spin off tornadoes. A confirmed, albeit rather weak tornado traveled two miles through Harwinton, Connecticut Friday with top winds of 85 mph. 

Social media early Saturday afternoon showed a funnel cloud or possible weak tornado near West Winfield, New York, which is very roughly halfway between Syracuse and Albany. The Hartford, Connecticut area was under a tornado warning for a time this afternoon.  Another apparent tornado appeared today near Angus, Ontario, north of Toronto.

That's all to say that this storm wants to cause problems. 

THE SETUP

Severe thunderstorms in New York and southern New England missed Vermont today, though there were some fairly strong storms in southwestern parts of the state.

The rest of the state was north of a warm front.  It was humid, overcast and showery in most of Vermont today, but we had nothing dramatic. Air  north of the front is too stable to cause much in the way of thunderstorms.

The warm front will continue slowly lifting north overnight and early Sunday and make it to southern Quebec. 

There could be a round of thunderstorms early Sunday, a few of which might be strong. But the main show will hit in the afternoon. 

We're still checking most of the boxes for ingredients that would create severe weather Sunday. We will be just south of a warm front in very humid, unstable air with a cold front and storm system approaching from the west.

Obviously, not everyone will see a tornado. Perhaps we'll get lucky and nobody will see a tornado in Vermont. 

But this isn't your usual wimpy storm outbreak. The severe thunderstorms will probably really mean business. Only some of Vermont's towns and cities will see a lot of damage, but there's a good chance a few places get blasted by winds well over 60 mph, which could cause a lot of damage.

I'll have many more details and updates when I post tomorrow morning. But you might start this evening storing away lawn furniture and stuff that would easily blow around in a bad storm.

And plan on spending Sunday in a place where you can quickly take cover in a sturdy building. 

 

How Our Big Vermont Heat Wave Compared With Past June Hot Spells

Thunderheads billow into the sky over St. Albans Bay,
Vermont during the peak of this past week's heat wave on
Wednesday.  The scattered showers and storms probably
prevented actual high temperatures from getting even
higher than they did
 Before the just-ended heat wave, I predicted this would be among the biggest June hot spells on record for Vermont.   

Sure enough, this was a biggie, but not the most extreme we've seen.

The most notable record was the minimum temperature in Burlington on Wednesday, June 19 of 80 degrees. That ties the all-time record for highest minimum temperature for any date in Burlington.

The persistence of the heat in Burlington overnight, was incredible. The temperature rose above 78 degrees from a little before 9 a.m. June 18 until a little after 3 p.m. June 20 when a strong thunderstorm dropped the temperature to 72 degrees. 

 The high temperature Wednesday in Burlington was 96 degrees, four degrees short of the record for the date and the all time record high for the month, also set on June 19 back in 1995. I have a feeling that we would have made it closer to 100 had the sun stayed consistently out all day. 

But the air was so humid it generated numerous showers and storms, which helped keep temperatures down by a few degrees. 

I'd still rate our recent hot spell as worse than the one in 1995. The average temperature in Burlington on June 19, 2024 was 88 degrees and due to a cooler night back then, the mean temperature on June 19, 1995 was half a degree cooler. 

And we only had two days in a row with temperatures over 90 back in that hot spell in 1995. 

 I did find a June hot spell way more intense than the one this past week.  Probably the worst June hot spell on record came in June, 1946. It would have been the second longest heat wave on record if one day had not fallen just short of 90 degrees.

On June 24-30 the highs in Burlington were 90,92,94,89,93,96,93.

Unlike this year, June, 1946 was chilly until that late month heat wave.

TRENDS

Overall, Burlington has had a grand total of 82 heat waves since the 1880s. A heat wave here is defined as three or more consecutive days in which the temperature reaches 90 degrees or more. 

This was only the 16th heat wave entirely within the month of June. Climate change is likely contributing to more hot weather in June than in past decades. 

Temperatures above 95 degrees used to be rare in June, happening in only a handful of years prior to this century. With Wednesday's high of 96 in Burlington, that makes four of the past five Junes making it to 96 degrees in Burlington. 

Junes with multiple days going to 90 or above seem to be increasing, too. Including this year, I found 13 Junes in the past century in Burlington with at least four days in the 90s. Seven of those Junes have happened since 1999. Only three of them were before 1983. 

More 90s this June are certainly possible, but unlikely. The best chances of it happening are this coming Wednesday, but that's really iffy.

There's plenty more time for additional hot days in July and August, though. 

The record for the most 90s in a single year still stands at 26, back in 1949. It would be a real tall order to break that record in 2024.

Potentially Dangerous Vermont Weather Weekend: Severe Storms, Local Floods, Tornado?

Here's something you don't see every day:
NOAA's Storm Prediction Center has
placed a small but real risk of a tornado
or two squarely over Vermont Sunday. 
 The exciting weather continues here in Vermont and the rest of New England as heat has given way to repeated bouts of severe storms. 

That's going to continue through the weekend. Especially Sunday.  An outbreak of severe storms, localized flash floods and even possibly a tornado or two could strike the Green Mountain State tomorrow. 

More on that in a bit. 

First, let's set it up. 

Thursday night's cold front, as expected, stalled in southern Vermont Friday. That suppressed most of the thunderstorms southward. Though there were storms mostly south of Route 4 Friday, the severe ones just missed Vermont, instead hitting the Capital District of New York, and Massachusetts and Connecticut.

Social media also showed what appears to be a tornado in Harwinton, Connecticut. I'm sure the National Weather Service office in Albany, New York will be investigating that. 

TODAY

That front is now beginning to lift north as a warm front. It'll be far enough north to allow for a dangerously hot day on the East Coast as far north as Connecticut.  Here in Vermont, it will touch off showers and a few thunderstorms. 

Storms today shouldn't be severe, but a few will bring some locally heavy rain. There's a chance of isolated flash flooding, but it's not a huge issue. At least today. 

A band of rain was already passing through northern Vermont, well north of the warm front early this morning. More showers and storms could break out at any time, though it won't rain all day. You'll notice the humidity in the air is lingering, but at least it's not as bad as it was this past week.

Yet, anyway.   

More showers and storms will hit overnight as the warm front slowly heads toward the Canadian border. 

SUNDAY

Yesterday, we were waiting for data on where that warm front would stall. If it stopped moving over northern or central Vermont, then the main threat would be flooding from repeated storms moving along it, like those boxcars on the railroad tracks.  

A supercell thunderstorm near Sheldon, Vermont in
May, 2018.  This one was rotating, but did not
produce a tornado. It's possible Vermont could see
a rotating supercell or two Sunday. There's a low
but definitely not zero chance of a tornado or two.
Strong straight line winds are a greater threat.

If it stalled in southern Quebec, the bigger threat would be severe weather. 

As of this morning the consensus is the front will stall just north of the border.  That means we still have the threat of some local flash flooding from torrential downpours, but the main threat is severe storms, at least as it stands now.

The Setup

The conditions actually look right for the risk of rotating supercells. The air will certainly be extremely humid. That means plenty of fuel for those storms. 

The main storm system will be coming in from the west. That means temperatures will begin to cool very high in the atmosphere, further increasing instability.

An important ingredient is that warm front. Often, rotating storms are able to get going just south of this type of stalled front. Winds are from the southwest if you're south of the front. Winds are more easterly north of the front. 

This allows winds to change direction and increase with height.  That puts a "spin" in the atmosphere, helping to create supercells.

That's not to say all storms tomorrow will be rotating supercells. But the risk is there. That's why NOAA' Storm Prediction Center at least for now has us squarely in a zone where a couple brief tornadoes are possible. 

This is a pretty rare set up for Vermont and New England. The last time I  can recall a set up like this was in May, 2018.  No tornadoes ended up touching down in Vermont that day, but we did have a couple rotating storms and lots of wind damage. 

The Result

The chances of a tornado are low, but not zero. Basically, there's a 5 percent chance of a tornado forming Sunday within 25 miles of any given point in Vermont, New Hampshire, eastern New York,  western Massachusetts or extreme southern Quebec. 

I'm fixating on tornadoes, but by far the biggest threat from Sunday's possible severe weather is strong straight line winds. Not everybody will see that, either. But I almost guarantee we'll see at least a couple reports of damaging winds.

Worse case scenario, there could be a quite a number of spots that see gusts strong enough to knock down trees and power lines There could even be a rare report of roof or structural damage from the winds, we'll see. 

Torrential rains will come with many of these storms, so there could be local flash flooding, especially if a particular spot is hit by two or three storms tomorrow, and/or if a particular spot has especially  heavy rain today. 

I also expect lots of cloud to ground lightning with Sunday's storms. I'd postpone that Sunday boating excursion on Lake Champlain to another day. I'd also cancel plans for a hike in the mountains. 

There could be large hail with the strongest storms too, but the risk of that is pretty low.

The Caveats

Forecasters still have a lot of questions as to how widespread any severe weather will become tomorrow. If a lot of clouds, showers and garden variety thunderstorms remain over the area all morning and early afternoon, that would limit the extent of the severe weather. 

If the sun breaks out more than expected ahead of the storms, that would worsen them. If that front stalls out further north or further south than expected, that would change the forecast, too. It's also unclear at this point which part of Vermont would be most at risk for dangerous weather. 

So, there will be updates tomorrow morning, and likely changes to the forecast. But this is how it stands now. 

For now, I'd plan on keeping ear out for any warnings that might come through on Sunday, especially in the afternoon and early evening. 

Friday, June 21, 2024

Heat Is Flushed Out, Humidity Not So Much, Weekend Storm/Flood Threat?

Roiling storm clouds over Milton, Vermont Thursday.
 Just as expected, some powerful thunderstorms formed over much of Vermont yesterday, with scattered reports of damage here and there.  

The worst of it was probably across the pond in Plattsburgh. The airport there measured gust of 61 mph.  There might have been higher gusts on those grounds, given the fact a small plane was flipped over and a few other planes moved around. 

Here in Vermont, it seems the strongest storms were in Chittenden County, where some trees came down in the North End of Burlington, along the lake in spots and in Charlotte.  The National Weather Service office in South Burlington reported a 48 mph gust. The storms extended into central Vermont, as Stowe reported some tree damage.

With that extremely humid air in place, the storms had a lot of moisture to work with and boy, did they take advantage of it! One report had an inch of rain in Burlington in just 15 minutes. We saw quite a bit of street flooding in parts of Burlington and South Burlington. 

Some local flash flooding was also reported in far southeastern Vermont. 

The good news is the heat advisory that had been in effect for three days has been dropped. It is a little cooler out there, and the humidity has diminished a little, too. At least in northern Vermont. 

We're by no means in the clear, though. We have more humid weather to get through, and the risk of storms and heavy rain/flooding through at least Sunday.  The weather is still going to be pretty active, folks! 

Let's take a walk through what's lined up next. 

TODAY

Dew points, a rough measure of how sticky it feels, were in the 60s this morning across Vermont. That's rather humid, but not quite as bad as this past week has been. 

Storm clouds loom over Colchester, Vermont
Thursday afternoon.

Dew points are in the more comfortable 50s up in southern Quebec and a little bit of that drier air might bleed briefly into far northern Vermont, which will be nice.

Yesterday's cold front is hung up in central New England. That means new rounds of showers and storms today, mostly in the the southern half of Vermont.

 Some of the storms could produce local deluges, and there might be some isolated instances of flash flooding.

The showers will be more scattered the more north you go, with not much excitement at all north of Route 2.

SATURDAY

That stalled front will start to lift back north through Vermont Saturday.  The humidity will become more and more noticeable during the day. But clouds will keep temperatures mostly in the 75 to 82 degree range, so the heat's not coming back. At least not here. It'll be torrid in the Mid-Atlantic states and Ohio Valley this weekend, but not really here. So that's good. 

The risk of showers and storms will last all day in the south, and there will be increasing chances through the day north. Saturday night looks pretty rainy, too.

With all the humidity around, we once again have the risk of heavy rainers in some of these showers and storms, so isolated flash flooding is again a risk.  This time statewide, not just in the south. 

SUNDAY

Depending on how things arrange themselves, Sunday could have its dangers. If that slowly moving front stalls across northern Vermont, the risk of flash floods would ramp up.  Storms will train along the front. You know what I mean, those proverbial boxcars following each other one after another. 

You could get inches of rain out of such a situation. 

Storms create chaotic looking skies over
St. Albans, Vermont late Thursday afternoon.

The computer models keep subtlety changing their minds on this, but the early bets are leaning toward the front stalling in far southern Quebec instead.

 If that happens, it would shift most of the flash flood risk across the border and not here. So stay tuned.

We're not completely out of the woods if the front stalls in Quebec. If it does, that puts all of Vermont in warm, soupy air. 

With a front and storm system approaching from the west, that would put us in play for strong, possibly severe storms. 

We'll have more on Sunday as we get closer to the event, stay tuned.

In central and southern Vermont, all this storminess might do more good than harm. Despite the storms yesterday, it's still pretty dry in those parts of the state, and more rain would come in handy. 

NEXT WEEK

Instead of one big heat blast, we're going to have pretty changeable weather.  Things could change, but Monday looks showery, Tuesday looks nice, Wednesday could be warmer and more humid with possible storms. 

But here's something you'll like. A cold front Wednesday or Wednesday night looks like it means business.  If that really does happen, we might get a nice, cool, dry blast from Canada. Bonus: There's far fewer wildfires up there than last year, so when we do get some refreshing air from Canada this summer, it's not full of smoke. 

However, even if we do get that nice cold front, hot air will be lurking not far to our south, and it would probably have an easy time oozing back into our neck of the woods.