Weather Blog

Winter of weather extremes continues...

Winter of weather extremes continues...
Frequent readers of this blog might remember an article I wrote on Oct. 29 highlighting what we called a long wave pattern in the atmosphere, where you get extreme events on both ends of the weather spectrum -- both warm and cold. Back then on that date, it ended up being warmer in Greenland than London.

That pattern has been the theme of the winter, with the last few weeks in December featuring the Western and Central U.S. being stuck on the cold side of this pattern, while the Eastern Pacific Ocean and Alaska was warmer -- did you know that we were colder in Seattle on Dec. 19th (27 degrees) than it was in Barrow, Alaska (28)?

Now, the pattern has shifted again, with the West Coast of North America basking on the warm side, while the Midwest and East Coast get the brunt of yet another arctic onslaught. The photo at the top of this story is a good representative of the pattern.  Note the west coast is in the much warmer oranges, while east of the Rockies, it's bundle up time.

Here are some specifics:

This morning in International Falls, Minnesota, it dropped to -42 degrees -- cold, even by their standards. Minneapolis was -18 with wind chills into the -40s. (And to those who saw my blog entry from a few days ago comparing "tropical" Minnesota with Alaska, um, the pattern has changed :) ) 

Chicago is expected to drop below zero (-8 by Wednesday night) with even St. Louis dropping to near zero.

On the other hand, out West, summer is making an appearance. In Brookings, Oregon it hit 75 Monday and was nearing the 70s again Tuesday.

In Southern California, many cities in the greater Los Angeles area were well into the 80s, with some of the warmer spots away from the Pacific pushing 90.

Now, the Northwest won't get quite as hot in the lowlands because of an expected inversion will trap cold air near the ground. That will keep temperatures in the 43-55 range, although the mountains will get quite warm. The high temperature at Mt. Rainier's Paradise Ranger Station (5,420 feet) is 54 degrees on Thursday -- could be warmer there than Seattle or Portland.

As we saw with our warm, dry November and very cold, snowy December, these patterns are not only extreme, but stubbornly persistent. Sure enough, we look to be on this warm, dry side almost all the way to the end of the month.

Beyond that, who knows. It's possible we could end up back on the cold side for February, or the pattern might mellow out and we'll get back to just regular rainy and 45.

P.S. I was going to write up an expanded article on inversions, but Dr. Cliff Mass beat me to the punch on his blog, and his is fantastic :)