Extreme Weather Pattern Is About To Create Lots Of Extreme Weather

As of Sunday afternoon, the map on the home
page of the National Weather Service was lit up
with lots of colors. That signifies lots of weather
watches, warnings and alerts, meaning there will
be a lot to talk about in the weather over the coming days.
The dark green you see in Vermont is a flood watch.

The jet stream and the weather is going haywire again, which means we here in Vermont, and a lot of people throughout Earth's Northern Hemisphere are going to have plenty of extreme and bizarre weather over the next week or so.

THE PATTERN:

The polar vortex, that whirlpool of very cold air that pretty much always wanders around the Arctic, or at least near it, all the time has split into two pieces. That's rare, but it does happen occasionally.

One piece is ending up roughly over central and northwestern Canada, while the other piece is somewhere around Siberia. That means western North America and parts of Europe and interior Asia are turning quite cold.

The split in the polar vortex means another big squirt of warm air will enter the far northern Arctic, including around the North Pole. (This has been going on a lot lately.)

That's bad, because it's been very warm (for them) across much of the Arctic most of this winter. Sea ice extent is running at record lows.

That burst of above freezing air coming in for the high Arctic will just make things worse.

UNITED STATES SCREWED, TOO

Meanwhile, down here in the United States, a big, strong ridge of high pressure - basically an out of season Bermuda High, is about to pump record warm temperatures into the eastern third of the nation.

Out west, the position of one piece of the polar vortex means it's going to be quite cold over the next several days in the western third of the United States. Again, that's bad. It's been incredibly warm in California all winter. Plants and crops are blooming much earlier than normal as a result.

This cold air is going to nip lots of agricultural crops, especially in California's Central Valley. Hard freeze warnings are up, and it looks like the too-early blooming plants are going to get nailed. I expect millions of dollars in agricultural losses because of this. There also might be some shortages of produce in your supermarket.

More inland, winter storm warnings, watches and advisories are up for wide areas of the Rockies and northwestern Plains state.

Big chunks of The eastern half of the country is in trouble with this weather pattern, too. The orientation of this Bermuda high will help draw massive amounts of moisture from the Gulf of Mexico, leading to repeated rounds of torrential rains in a broad band from Texas to Michigan.

Many - but not all -  of these areas have had quite a lot of rain this month already. Some areas from northeastern Texas through Arkansas and into southern Ilinois could get seven or more inches of rain over the next week. There is a high chance of flooding, as you'd imagine.

VERMONT EFFECTS:

We barely got clipped by that storm that zipped by to our south last night. Most of us got one to three inches of snow, with a little less around Burlington and up to six inches and southern and eastern parts of the state.

It's kind of mild today, and some of the snow is starting to melt. But you haven't seen anything yet!

After the 30s today, it'll get into the 40s Monday and 50s to low 60s Tuesday and Wednesday. That's definitely record territory.  This will be an unusually humid warm spell for this time of year. When the air is moist, snow tends to melt much faster than when the air is dry.

The start of a thaw. Snow sliding off my St. Albans, Vermont
roof today clings to the eaves in foot-long sheets. With
forecasts for highs near 60 by Tuesday and Wednesday,
this snow will be gone soon. 

Also, partly because of the humidity, temperatures will remain extremely warm Tuesday might.

Lows early Wednesday will probably stay above 50 degrees in the Champlain Valley. That's normal for late May, not February! That'll keep the snow melt going at a fast clip.

Also, there will be a fair bit of rain during this, especially over northern areas, which will be closer to a stalled front.

The combination of melting snow and the rain could lead to flooding. Most of Vermont and northern New York is now under a flood watch Monday through Wednesday.

The biggest problem here is the ice jams left behind from that other mega-thaw in January. They're still there, and this thaw and rain will either dam up water behind the ice jams, make the ice jams even bigger, or move them into more populated areas.

As we found out in towns like Swanton and Johnson back in January, this can quickly lead to destructive flooding.

So yeah, we'll probably have quite a bit to talk about in the weather department over the next several days.