John looks to me that this is where all the "western states" snow has gone. This must be the influence we are under also, read some stuff on the "Greenland Block" although dont really understand what I read. Can you elaborate on the "Block" in laymans terms? For 2 weeks straight they seem to get it one after the other. Thank you getting worried about Tog trip on 1-7-12 1-14-12
AK & NWT Getting hammered
- Thread starter rmk4ever
- Start date
I guess I would have to read what you read about a "Greenland Block" to be able to elaborate, but you are right about Alaska and far NW Canada stealing most of the thunder so far this snow season. Not just for the Rockies, but for much of the northern US. It is not just AK and W. Canada. but so too has far eastern Russia, Greenland and at times northern and central Europe.
You can almost think of the jetstream in both the northern (and southern) hemispheres as a rubber band that is sitting across the top of a basketball (bottom for the southern hemisphere). It is never large enough to fit completely around the ball, but it does get more elastic or larger during the cold seasons and dips further south. All the real storminess occurs underneath the jetstream and is why us folks at the mid latitudes get areas of low pressure to track through and why the lows are so much stronger in the cold season that in the warm, because the jetstream has dipped further south and is stronger and fuels stronger low pressure systems at the surface.
If you can imagine trying to pull the rubber band down in one spot, you might be able to do it, but it will also cause the rubber band to want to pull up in other spots across the ball. Now, pull the rubber band down in two or maybe three spots and you have what has been going on across the northern hemisphere for the past 4-6 weeks. The jetstream has been pulled down over Alaska, Greenland and eastern Russia, causing it to be pulled further north in other areas of the northern hemisphere (like most of North America).
Where the jetstream is pulled down, it is called a trough and all the storminess in the atmosphere occurs in relation to these troughs and is why Alaska, Greenland and eastern Russia are seeing a bumper year for cold and snow right now.
As far as Greenland goes, there has been little to no blocking. There has been the opposite; a trough and what is considered a very positive or progressive setup. What we would like to see is the opposite occur. A blocking high to establish and cause a trough to dig into North America and bring us cold and stormy weather. Getting rid of the trough over AK would be very helpful as well.
Problem is, the atmosphere seems to like to be in that position so far this cold season and there are little in the way of signs of anything changing in the next 10 days. There are some signs of change beyond that, but the reliability of the models really starts to drop off as you enter into that time frame.
Hope this makes some sense.
-John
You can almost think of the jetstream in both the northern (and southern) hemispheres as a rubber band that is sitting across the top of a basketball (bottom for the southern hemisphere). It is never large enough to fit completely around the ball, but it does get more elastic or larger during the cold seasons and dips further south. All the real storminess occurs underneath the jetstream and is why us folks at the mid latitudes get areas of low pressure to track through and why the lows are so much stronger in the cold season that in the warm, because the jetstream has dipped further south and is stronger and fuels stronger low pressure systems at the surface.
If you can imagine trying to pull the rubber band down in one spot, you might be able to do it, but it will also cause the rubber band to want to pull up in other spots across the ball. Now, pull the rubber band down in two or maybe three spots and you have what has been going on across the northern hemisphere for the past 4-6 weeks. The jetstream has been pulled down over Alaska, Greenland and eastern Russia, causing it to be pulled further north in other areas of the northern hemisphere (like most of North America).
Where the jetstream is pulled down, it is called a trough and all the storminess in the atmosphere occurs in relation to these troughs and is why Alaska, Greenland and eastern Russia are seeing a bumper year for cold and snow right now.
As far as Greenland goes, there has been little to no blocking. There has been the opposite; a trough and what is considered a very positive or progressive setup. What we would like to see is the opposite occur. A blocking high to establish and cause a trough to dig into North America and bring us cold and stormy weather. Getting rid of the trough over AK would be very helpful as well.
Problem is, the atmosphere seems to like to be in that position so far this cold season and there are little in the way of signs of anything changing in the next 10 days. There are some signs of change beyond that, but the reliability of the models really starts to drop off as you enter into that time frame.
Hope this makes some sense.
-John
steve_in_il
Member
John,
That's THE BEST "layman's terms" explanation I have ever seen about jet streams! Nicely done....
Steve
That's THE BEST "layman's terms" explanation I have ever seen about jet streams! Nicely done....
Steve