Vermont Once Again Sits Out U.S./Canadian Weather Extremes

Pretty clouds and some fall foliage in South Burlington,
Vermont on Sunday. Extreme weather around the 
United States this week is avoiding Vermont

 We here in Vermont are facing a relatively cool October week, but nothing that out of the ordinary for the third week in October.  We're a bit of a rare exception.  

The weather is much more interesting almost everywhere else in the nation as temperature and precipitation extremes reign supreme.  Record cold, record heat, flooding and even a snowstorm are in the cards for many areas. 

A sharp cold snap for this time of year is unleashing Canadian air on a vast section of the nation's south and middle. Freeze warnings and frost advisories extend from Colorado to southern Ohio and on down to Alabama and Mississippi.

Quite a few record low temperature record will be set in this area over the next few days.  High temperatures will be near record low levels, too. Normally, it's in the upper 60s his time of year in St.Louis. They'll be lucky to get to the upper 40s today.

There's a decent chance Birmingham, Alabama could hit 32 degrees Wednesday morning. If it does, it will be the earliest freeze there in 109 years. 

Eastern Kentucky faces three consecutive mornings with temperatures in the 20s, definitely a rarity for them in October.

Way further north, there's actually a winter storm warning in the Upper Peninsula of Michigan. Lake effect snows there are dumping up to six inches of wet snow.  Winds are also gusting as high as 50 mph in that mess. 

Widespread record cold in the United States has been becoming increasingly rare with climate change.  Most months, we have far more record highs in the U.S. than record lows.  In July, August and September, there were at least ten times more daily record highs than record lows in the U.S.  That's the first time we had three consecutive months with that ratio since at least 1890. 

And, despite the cold week in the Midwest and South, there's still record heat to be found. In the Pacific Northwest and parts of western and northern Canada, the issue is record heat.  On Sunday, Seattle, reached 88 degrees, by far the hottest on record for so late in the season. Before Sunday, it had never been warmer than that after October 1. 

In Juneau, Alaska on Sunday, it was 62 degrees. Like the situation in Seattle, this was by far the latest in the season it has been so warm there. 

On Saturday Salem, Oregon reached a summery 92 degrees by far the warmest on record for so late in the season there, too.  Portland reached 87 degrees, breaking the record high for the date by seven degrees.

It's been at least 80 degrees in Portland eleven times so far this October.  Portland typically reaches 80 degrees in less than  half of all Octobers. 

Record heat has also been reported across British Columbia, Canada. 

Meanwhile, eastern Maine is bracing for the risk of flooding tomorrow.

The reason for all this chaos is what is known as an "amplified" jet stream. That means the usual bulges northward, and the dips southward in this jet stream are larger than normal. There's been a big ridge in western North America contributing to the heat.

On the front side that ridge, the jet stream takes a big dip into the middle of the United States. That explains all the cold weather there, since that dip is pulling cold air down from northern Canada.

Then, the jet stream takes a big northward swing off the East Coast. That brings tropical moisture northward. It'll miss most of the U.S., but clip eastern Maine, which explains the flood watch.

Here in Vermont, we're kind of in a sweet spot, though that doesn't necessarily mean glorious weather. We're a little too far east to get that cold blast directly. By the time the chilly air rounds the bend and starts coming at us from the southwest this week, the chill will modify into something that is just sort of cold.

A cold front will come through today and this evening with some light rain. A storm will form along that front and grab that Atlantic moisture I mentioned. But that will all be too far east to give Vermont all that much rain. It'll target eastern Maine instead. 

The jet stream is still showing signs of wanting to flip to a new arrangement toward next weekend and next week.  Signs are suggesting a northward bulge over the eastern United States, which would steer warmer than average and probably drier than average weather into our neck of the woods.