The Polar Vortex

posted in: Michigan Weather Forecast | 18

With the coming of Meteorological Winter next week I thought I would give a quick reminder of what the polar vortex is.  A polar vortex is an upper-level low-pressure area lying near  the Earth’s poles. There are two polar vortices in the Earth’s atmosphere, overlying the North and South Poles.

The breaking off of part of the vortex is what defines a polar vortex event. But it actually occurs when the vortex is weaker, not stronger. That might sound weird—but it actually makes sense. Normally, when the vortex is strong and healthy, it helps keep a current of air known as the jet stream traveling around the globe in a pretty circular path. This current keeps the cold air up north and the warm air down south.

But without that strong low-pressure system, the jet stream doesn’t have much to keep it in line. It becomes wavy and rambling. Put a couple of areas of high-pressure systems in its way, and all of a sudden you have a river of cold air being pushed down south along with the rest of the polar vortex system.

Recent research has found the very upper part of the atmosphere, called the stratosphere, can suddenly warm up. The temperature may warm over 100 degrees in just a few days at an altitude of 50,000 feet. These rapid warming periods are called Sudden Stratospheric Warmings (SSW).

The SSW triggers movement of arctic cold air at the surface. The stratosphere warms, expands and pushes on the Polar Vortex. The Polar Vortex gets “disrupted.” The Polar Vortex will then move off the North Pole and shift southward.


Wow!  We have a colorful warning and hazards map from the NWS the morning – the pinks and blues denote snow warnings and watches which stretch from the U.P. all the way to the west coast.  The tan colors are high wind warnings and watches which stretch from Michigan to New Mexico.  We have a high wind watch for a good portion of lower Michigan along with a lakeshore flood watch all going into effect tomorrow at 7am.

From the NWS:
We still expect the strongest winds to be along Lake Michigan
south of Grand Haven with wind gusts of 50 to 60 mph by late
morning through the afternoon. Further north and inland we expect
wind gusts peaking at 45 to 55 mph. This will be a stronger and
longer-lasting wind event than the storm last week, causing more
power outages and worse beach erosion than that storm.

 

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Mark (East Lansing)
Mark (East Lansing)

Getting lightning and thunder now, two days before Thanksgiving. Go figure.

Mookie
Mookie

Through Christmas, the coldest high Accuweather currently has is only 31 degrees. So while it could be a little cold relative the averages, the models aren’t seeing any big time Polar air. That also means any snow we get likely won’t stick around for very long.

Rocky (Rockford)
Rocky (Rockford)

It looks like it is time to review the facts again!
1. 9 out of the last 11 months with below normal temps!
2. Most expert predictions give us above normal snowfall this year!
3. The last 2 winters have lingered into April yet some here say winters are short in West MI!
4. Most predictions this year also say winter will hang well into Spring!
5. Rock n roll will never die!
6. MV and Slim give us an incredible blog!
7. Winter is clearly the best season, bringing plenty of outdoor winter sports opportunities!

Mookie
Mookie

April 2019 had one day of snow on the ground it was only 4″. April 2018 wasn’t much better. I guess that counts as another month of winter now? LOL

Slim

Of course April of 2018 was the 4th coldest on record at Grand Rapids.
Slim

Rocky (Rockford)
Rocky (Rockford)

Don’t tell mookie! He ignores facts as much as the Republicans in DC! Incredible!

Mookie
Mookie

Yeah an average high of upper 50’s for April 2019. Guess that’s winter LOL

Rocky (Rockford)
Rocky (Rockford)

Wow you are homeless!

Andy W
Andy W

That’s harsh….

Rocky (Rockford)
Rocky (Rockford)

Hopeless.

Barry in Zeeland
Barry in Zeeland

Slim, good point you made below about the models backing off on the cold now for December. I believe last year was the same way about this time in that first it was looking cold for December, but then what actually happened was the opposite. It would be interesting to see a side by side comparison with this year and last year starting with September through now with regards to temps, precipitation, etc. Both years have seemed so identical. Maybe a good Saturday post sometime?

Slim

Ok, here is a quick comparison. Mean temperature September 66.1° 2018. 66.4° °2019. H/L for the month 90° 40° 2018. 88° low 48° 2019. Rain fall 5.93” 2018. 7.32” 2019. October mean temperature 50.4 in 2018 and 50.2 2019. High for the month 84 2018 77 2019. Low for the month 27 2018. 31 2019. Rain fall 5.69” 2018 7.13” 2019. Snow fall trace 2018 0.3” 2019. November mean temperature 34.6 2018 34.6 so far this year. Highest for the month 52 2018 and 53 so far this year. Lowest temp 20 in 2018 and 15 so far this year.… Read more »

Barry in Zeeland
Barry in Zeeland

Wow, that was a fast response! Yes very close together, and I believe the day the pattern shifted each year in October was within a day or two of each other as well. If money could buy weather, I’d order last years December in a heartbeat! Thanks Slim!

Slim

We now wait to see if this mid week storm is a true big time November storm here in the Great Lakes area. In looking ahead one item that kind of stands out is that the models are now backing off in fact way off on any cold for the first half of December and I have to wonder if December 2019 will end up more like last year? This morning is a little colder than the forecast had last night and there is a lot of frost here this AM with a current temperature here of 30.
Slim

INDY
INDY

Amazing most of last Summer we had the polor vortex overhead just to our northeast with some cool weeks…Today is the calm before the storm get to the store and grab more tomorrow looks nasty possible power outages in west Michigan we keep having havoc storms around here.. Interesting to see if they cancel the big Macy day parade in new York due to the heavy winds heading there also that maybe a first!! Wild Weather we call this have a great Tuesday …INDY

Mookie
Mookie

Look at all that snow out west and once again Southern Lower Michigan is quiet. Our winters here are short.

Rocky (Rockford)
Rocky (Rockford)

In your dreams!

Rocky (Rockford)
Rocky (Rockford)

I like the sound of the polar vortex, hopefully this pays us multiple visits this winter!