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.  

Nation's Cold Snap In Perspective: Intense But Far From The Worst Ever. Vermont Cold Wimpier, Too

Brutal cold waves are still always possible in Vermont,
but they are becoming less and less likely or severe
as climate change continues to take hold

The Washington Post had a good analysis of the cold wave that has been making headlines in the United States for the past several days now. 

It's true that this Arctic cold snap was a humdinger. A few hundred daily low temperature records were set in a pretty wide area of the nation.   

Nashville, Tennessee got below zero for only the second time since 1996. Thirty states had wind chill warnings or advisories. It was 54 below in Montana, with wind chills of 70 below.

In that Washington Post article, Matthew Cappucci writes: 

"But despite the bitter cold, few monthly or all-time cold records were set. Simply stated, even a severe and disruptive Arctic outbreak isn't netting the kinds of records or headlines that this of the past did."....

.....The Earth is heating up. Warm extremes are turning warmer, and the cold generally isn't as cold. Human-caused climate warming is moderating cold snaps, making them less severe. They can still be bitter and dangerous, but they're not quite as bad as they used to be."

As of Wednesday, more than 330 daily record low temperatures have been set this month in the United States at many of the thousands of weather stations scattered around the United States. 

Daily records are relatively easy to beat, especially if a cold snap hits on a date that by coincidence, have historically had few particularly cold days. All-time monthly records are much harder to beat, and there have only been two of them in this Arctic outbreak.

All-time records for any month are really, really hard to achieve, and so far we haven't seen any this month.  

Most  cold snaps are not lasting very long either, as opposed to some winters, like 1936, 1969, 1977 and 1978 that went on for weeks.  

The national cold wave that we've had this week is already in the process of breaking down, after just a few days. By next week, pretty much the entire nation is forecast to be warmer than average.   

Weeks like this in which record lows across the nation outnumber record highs are becoming rare, too. As Cappucci notes. Nowadays, it's usually the opposite.

Overall all of 2023, there were 31,611 warm weather records compared to only 10,493 cold weather records. 

Back in the bad old days, or good old days, depending on your perspective, some historic national cold waves made this one look like a January thaw. 

In 1899, an intense cold wave and blizzard sent temperatures down to an incredible minus 2 in Tallahassee, Florida. There's an old photo of lawmakers have a snowball fight on the Florida capital steps that day. 

This cartoon is slowly becoming less and less relevant
in cold states like Vermont as climate change generally makes
severe Arctic outbreaks less frequent, less intense and
less long-lasting than they used to be. 

That 1899 cold blast sent temperatures down to 9 below in Atlanta, Georgia and 15 below in Washington DC.  Every state in the U.S. (Hawaii wasn't a state then) got below zero.

In February, 1936, it got as cold as 58 below in South Dakota and 60 below in North Dakota. 

The average temperature for a five week period ending 4th the close of February in Devils Lake, North Dakota was an incredible 21 below. Langdon, North Dakota remained continuously below zero for 41 consecutive days. 

January, 1949 was the coldest on record in all of the far western states. Snow fell in downtown San Diego. Los Angeles saw snow on three consecutive days.  

As recently as 1977, on this date, January 19, a cold wave created snow flurries for the first time on record around Miami, Florida.  Arguably the last truly destructive freeze in Florida was in 1985.

The only recent cold wave I can think of that even sort of rivaled those of the past was the one in February, 2021.  More than 250 all-tine cold records were set or tied in an area ranging from the Canadian border to Texas and Louisiana. Cold waves like this are now exceptionally rare. I'm guessing we won't ever see anything like February, 2021 again. 

By the way, that February, 2021 cold wave fueled speculation that climate change was messing with Arctic weather circulations in the winter. Perhaps a warmer world was warping the polar vortex and the jet stream, making such intense cold waves an occasional risk despite the fact that overall we are warming.

The idea that the polar atmospheric circulation is getting all mucked up by climate change is still a matter of debate. It's not quite settled science yet. 

 VERMONT PERSPECTIVE

Starting today, Vermont is forecast to endure three consecutive days with highs in the single numbers and teens, with lows within a few degrees either side of zero.

This is going to seem bitterly cold, because we haven't had any truly frigid weather yet. We're not acclimatized to what should be regarded as a run of the mill January cold spell.

Remarkably, through Thursday, the temperature in Burlington so far this winter had never gotten lower than the teens.  That I'm sure is by far the latest in the season it hasn't gotten under 10 degrees yet. 

Despite the warmer winters, it can still get frigid in Vermont. Every once in a while it can get to 20 below in Burlington, Vermont  but that has become rare. The last time it was 20 below zero in Burlington was on January 7, 2018.

If I'm not mistaken, the last time it was colder than 25 below in Burlington was in January, 1994.  Back in the 1960s and 1970s, it would get that cold during a good half of all winters. 

Arctic cold snaps in Vermont have tended to get brief, too.  In decades past, we'd sometimes have a week where every day got into the teens, 20s and 30s below zero.  That's changed. I haven't seen a sharp cold spell last more than three or four days since the early 1980s. 

From a historical perspective, this weekend's expected cold is absolutely no big deal. In past decades, it would have been regarded as pretty seasonable. 

Here are a few bone chilling extremes that just might be permanently a thing of the past, thanks to climate change:

In January, 1857, temperatures fell into the 30s and 40s below zero across most of Vermont. At that time, most thermometers had mercury, which freezes at 40 below, so it's hard to tell exactly how cold it got. Burlington had a low of 29 below and a "high" of 16 below.

The entire winter of 1917-18 was frigid in Vermont, The temperature was continuously below freezing at Burlington from December 26 to February 11, except for a few hours on the afternoon of January 11. 

Incredibly, the temperature was continuously under 10 below from the evening of December 26 to the late morning of December 31, 1917  in Burlington.

In the winter of 1933-34, temperatures got below zero on 45 days in Burlington, including 23 days that were in the teens or 20s below zero. This included a late December cold snap that dropped temperatures to 50 below zero in Bloomfield, Vermont, to this day the coldest ever measured in Vermont. 

In January 1968, high temperatures in Burlington were below zero for five consecutive days and each morning during that spell were in the 20s below zero.  Twelve days that month were in the teens below zero.

Arguably the last of the greatest Vermont cold spells was in February, 1979. All but one of 11 consecutive days from February 9-19 were in the teens and 20s below zero in Burlington. The all-time record low in the city of 30 below was tied on February 12. 

In West Burke, all but two days in a 10 day stretch ending on February 21 were in the 30s below zero. The two "warm" days were in the 20s below. 

Despite the warmth of recent winters, we're sure to have in the future a few nasty winters thrown in which temperatures get far below zero, or stay below zero for a week or more. But it won't  happen much. Warm winters like the one we're experiencing now will be the norm.

This is definitely not your grandfather's Vermont winter climate. 

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. 

Buckle Up: Rest Of Hurricane Season To Be Horrendous

They're still trying to restore all the power on the East Coast after Hurricane Isaias, but that destructive storm looks like it might be just a foretaste of what's to come.   

Damage from Isaias this week in Pennsylvania.

The National Hurricane Center updated its seasonal forecast for this year, and it's ominous. So did the hurricane experts at Colorado State University. 

According to CBS News, CSU is now "predicting 24 named storms, including 12 total hurricanes and 5 major hurricanes - each figure about double that of a normal season. If the forecast proves accurate, 2020 would be the second most active Atlantic hurricane season, behind only the record-shattering 2005 season, which brought Hurricanes Katrina and Wilma." 

The National Hurricane Center predicts between 19 and 25 named storms, including seven to 11 that would become hurricane and three to six being major hurricanes. 

All these figures include the nine named storms we've already had this year.  There's no record of any  year having nine named storms by now - we are already on a record pace.

We've seen in Isaias what can happen if a hurricane or tropical storm has a long track through a populated are of the nation. 

Isaias was "only" a tropical storm as it headed up the East Coast, but still killed several people, caused an estimated $1 billion in damage and cut power to more than 3 million homes and businesses. 

For the moment, the Atlantic Ocean and the atmosphere over the ocean is playing possum. As of this morning the National Hurricane Center not seeing any suspicious areas that could develop into tropical storms or hurricanes. There's one lonely area of disturbed weather out there, but it's not expected to amount to anything. 

I'm sure that will change soon, and I suspect by late August and September, there will be so many storms and potential storms lurking out there that it will be almost impossible to keep track of them all. 

Warm ocean waters are like jet fuel for hurricanes, and some parts of the tropical Atlantic where storms either form or move over are at record or near record levels. 

This hotter than normal water is probably a combination of a natural cycle and climate change, which tends to make warm peaks even toastier and cool periods not all that chilly. 

Other reasons for this expected onslaught of tropical storms and hurricanes is a wet central Africa and lower than normal air pressure over the tropical Atlantic, according to CBS and other news organizations.

The wet ground and conditions over central Africa would help disturbances moving westward off the coast of Africa into the Atlantic Ocean be stronger and more organized. These disturbances often turn into tropical storms and hurricanes. 

If these disturbances have a healthier start when pushing away from Africa, they tend to be more likely to develop. 

The low air pressure in the tropical Atlantic means air there has a tendency to rise. That rising air creates thunderstorms, which can turn into tropical storms and hurricanes, reports CBS.  Also, upper level winds are weak in the Atlantic.  

Strong upper level winds tear apart those thunderstorms I just mentioned, stopping tropical storm formation in its tracks. Weak upper level winds let those thunderstorms develop nicely, increasing the chances of storms. 

Even if all these factors come together to make this busy hurricane forecast spot on, nobody knows where any of these tropical storms and hurricanes will go. Will atmospheric conditions make them turn north, harmlessly moving into the cold open waters of the North Atlantic to die alone?

 Or will the storms crash into populated coastlines, including those in the United States to cause much more havoc than we've already seen from Isaias and Hurricane Hanna in Texas back in late July?

Whatever happens, buckle up.  Its going to be a wild ride.  

Also, here's a couple news videos to show what can happen from "only" a tropical storm Isaias

Damage on the Jersey shore:

And in Long Island, New York: