Jet Stream Meanderings Responsible For Weird Weather, Areas Of Record Heat

A quick morning downpour today precluded breakfast out
on the deck, but gave the plants a nice watering. 

The weird weather pattern since yesterday has pretty much worked out as forecast.  Which is an accomplishment.   When the weather is odd, the chances that a forecast will be dead wrong go way up. Not on this case, so far. 

Batches of showers and thunderstorms have been heading due south from Canada, mostly moving through New York and Pennsylvania, and for the most part bypassing Vermont.

One patch of showers did wander into Vermont this morning, dropping a quick quarter to third of an inch of rain to some areas, just to water the gardens a bit. w 

The conga line of storms and showers will renew themselves later today and tonight, again proceeding south through New York and Pennsylvania.  These repeated rounds of heavy rains could lead to local flooding in both states.  Vermont looks safe from that, anyway, but it does remain cool for the season. It will stay on the cool side until Friday. 

Meanwhile, western and central Europe is recovering from the opposite problem - a record breaking heatwave. Some cities reported all-time record highs, and others set records for the entire month of June. 

Examples cited by the Washington Post include:

The French cities of Biarritz (109.2 degrees), Rochefort Saint-Aignan (105.1 degrees) and Tarbes (102.6 degrees) set all time record highs over the weekend. Roughly 200 cities in France established new record highs for the month of June.

In Spains's Basque area, San Sebastian reached 111 degrees, breaking its all time record high by a wide margin.  

The Czech Republic established a new record high for the month of June with a Sunday temperature of 102.2 degrees in Husinec.  

Poland set a new June record with a high of 100.9 degrees in Slubice. Switzerland also established a new June record high of 98.4 degrees in Beznau.  

Meanwhile, the record heat also grinds on in the Midwest and South in the United States. Minneapolis hit 101 degrees on Monday, a record high and their first 100 degree temperature since 2018. record highs of near 100 degrees are in the forecast for southern cities like Atlanta.

The heat in Europe and the middle of the United States, and the cool, weird weather here are all related. 

The jet stream, which guides weather systems generally west to east across the Northern Hemisphere  normally has lots of bumps to the north and dips to the south. It's usually hot under the northward bulges and cooler under the dips. 

In the summer, the dips and bulges in the jet stream aren't as pronounced and big as they are in the winter. So, more often than not, the hot areas are only kind of hot and the cool areas are just kind of cool.

But the jet stream in the past few days has featured huge northward bulges and big plunges to the south, which is odd for this time of year. So, the extremes have been pretty extreme. On top of that, the bulges and dips haven't been moving around much so everybody gets stuck under roughly the same weather day to day. 

That's why there's a flood threat in New York and Pennsylvania. Those storms from Canada keep going over the same spots. 

Climate change is a factor, too.  The heat under those northward bulges in the jet stream in central North America and Europe is given an added boost by global temperatures that have risen in the past several decades.  Temperatures that would have just missed hitting a record high, say, in the 1970s are now smashing records.

These bigger than normal summertime bulges and dips in the jet stream might also be related to climate change. The science is still uncertain with this. But some experts think that because the Arctic is warming faster than the mid-latitudes, there's less of a north to south temperature contrast.

The jet stream thrives on a big contrast and in those conditions behaves itself. The theory goes that the relative lack of a contrast between the North Pole and down where we live is making the jet stream meander more than it would otherwise. 

That meandering jet stream gives us those big bulges northward where they had the heat waves, and those big plunges south, one of which has given us the past week's worth of cool, odd and unsettled weather. 

The jet stream looks like it will untangle itself a bit in the coming days,  hopefully resulting in more or less average summer weather for most of us.