Sunday, February 26, 2017

Unprecedented Extreme Weather In Recent Days Has Climate Change Fingerprints

Day lily shoots beginning to sprout in my garden in
northwestern Vermont today after unprecedented
February heat. Very weird. 
On Thursday, when Burlington, Vermont reached 63 degrees to establish a new all time record high temperature for February, I said that was one of the weirdest weather days I'd ever seen.  

Then Saturday came along. The temperature in Burlington soared to an unbelieveable 72 degrees, smashing the monthly record set just two days earlier.

And it broke the record by nine degrees, a margin I'd previous thought to be impossible for any monthly record any time of year.

I have to say Saturday really blew my Vermont weather mind.

The 69 degrees in Bennington Thursday broke the record for the hottest recorded temperature in the entire state of Vermont for February. That was broken Friday by a 71 degree reading in Bennington, followed by Burlington's 72 degrees Saturday.


Add to that the dozens of all time February record highs in cities across the nation in the past month. And the very odd severe weather outbreak that prompted tornado warnings Saturday as far north as Pennsylvania and New York, which is much further north than I've ever seen in February.

They're even investigating whether a tornado touched down in western Massachusetts.  In February, when everybody is supposed to worry about snowstorms, not twisters.

Then there's the incredible California storms this winter, and the deep northern New England snows that preceded the record warmth before it all melted away.

The weather is really off the rails, that's for sure.

What's going on?


I'll start with caveat that you've heard before, but it's important for context. A single weather event, even one that is extreme as we saw Saturday is not proof that global warming exists, and is not solely caused by global warming.

A lot of influences that had little or nothing to do with global warning were all factors that caused the wacky weather.

Still, what has happened with the weather in recent weeks is consistent with what climate scientists have said would happen in a warming climate.
Damage from a possible tornado in western Massachusetts
Saturday. If confirmed, it would be the first recorded New
England tornado in February. Photo by Alex Kant.

The scientists keep saying the extremes keep getting more extreme with global warming, and the extremes happen more frequently.

Of course, you get more frequent and stronger heat waves with global warming (duh!), but the phenomenon can also cause bigger floods, bigger droughts, possibly bigger storms, even occasionally bigger cold waves.

It can also relocate where storms hit. Maybe tornadoes will hit further north earlier in the season than usual. That idea is not proven by climate change scientists, but it makes sense.

If it's warmer and more humid in the winter further north than it used to be, severe storms and tornadoes could move more north, too. After all, warmth and humidity is one ingredient necessary for severe thunderstorms.

The bottom line is , like it or not, global warming is here, and ou should expect more extremes.

What's happened with weather in Vermont over recent weeks and decades shouldn't be taken as the definitive proof of global warming.

But it illustrates the way things change.


Weather records for Burlington, Vermont go back to the 1880. There's always been weather extremes, and you can pick them out:

Two enormous blizzards in 1888. 64 degrees in January, 1906. 100 degrees in July, 1911. A devastating flood in November, 1927. A terrible hurricane in 1938. Huge summer heat waves in the 1940s.

When it comes to weather, things happen.  
Will climate change give us a stormier future?

It's just that now, the pace of the extremes has picked up, and gotten more extreme.

Picking apart the Burlington climate data further, he's one example of what I mean.

The previous record for the hottest February temperature on record was 62 degrees on February 19. 1981. That was broken by that 63 degree reading Thursday, then the 72 degrees Saturday.

Meanwhile, until 1990, the earliest 70 degree reading in the spring was on March 20, I think 1903. That record was broken relatively recently, in 1990, when it got up to 72 degrees on March 15. Then that record was broken just last year, when the temperature reached 70 on March 9. And that earliest 70 degree record was broken Saturday.

Plus,  remember that previous record earliest 70 on March 20? That was replaced just five years ago, in 2012, with Burlington's earliest 80 degree record on March 20 that year.

I suppose all these records aren't incredibly consequential for most of you who live in the real world.

But then add on the increasing pace of extremes during all times of the year in Vermont. And add all those extremes practically everywhere else in the nation and the world and things get really screwed up fast.

Unlike temperatures, which you can measure precisely, the definition of "extreme" is more subjective.    That's especially true if you're trying to determine whether the frequency of extreme weather is increasing. How do you measure that?

There's no precise way.

However, there's obvious real world consequences to this rising tide of extremes. (Which includes literal rising tides in vulnerable coastal locations.)


This new regime of extremes is changing our lives. I said that the winter heat waves of recent years in Vermont aren't radically alterning your life, but they are affecting you.  
Flooding along Lake Champlain in Colchester, Vermont
in 2011. Will we need to get used to more extremes
like this record flood?

Vermont depends upon winter tourism. All that snow in mid-February was great, but resorts across the state watched helplessly in the past few days as all that snow dissolved.

Maple sugarers have had to adjust their season and start earlier than they used to. No sugaring was ever done in February when I was a kid. Now it's routine.

Plus, you have to wonder how the warmth on recent days will affect the length and quality of this sugaring season.

Here and further south, trees and plants are budding, and they will inevitably get nipped with a return of more normal weather in March.

Did the Vermont apple crop get damaged? Will the peach crop further south in the United States get wiped out because it's been warm for weeks and a big cold wave will come down from Canada in March, as almost always happens?

Then you start thinking about the apparent overall increase in storms, droughts, floods and whatnot in Vermont, the United States and the world, and pretty soon you're talking about lots of real lives and real money.

Sounds bad, and I don't have the policies or the plans on how to deal with it.

We're all pretty much not totally capable of completely adapting to the changes and extremes in the weather and climate. But we're going to have to do our best.

The weird weather in Vermont over the past few days was a novelty.  Future extremes might be more dangerous than shorts and t-shirt weather in February.

It's going to be a wild ride.

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