Absolute Vorticity

Both long range(3-4 weeks) GFS/EU ensembles forecast show a very healthy snow cover for much of Alaska and Yukon territory with much of western and Central Canada picking up substantially also

tron777 wrote: ↑Fri Sep 10, 2021 10:36 am If I remember right, mid Sept is usually the avg for when the melting process ends and the re-freezing process begins so we're pretty much right on cue there. Good news for early snow and cold air build up for sure, but as usual, the questions remain how it'll get down here. Right now, AK and Canada are going to be the beneficiaries as you would expect them to be in Sept / Oct. I like the odds still of an early start to the season. One wild card though that I am hearing talk of is another +IOD event for the upcoming winter, so we'll need to keep an eye on that. Hopefully it doesn't get out of control like a couple of winters ago.

Not to concerned with IOD being a big influence . Last I checked, a couple weeks ago it was about -.30 and expect to slowly rise to near neutral by December. So at least we know it won't be raging one way or the other going into the winter months like a couple years ago.

Bgoney wrote: ↑Fri Sep 10, 2021 11:03 am Both long range(3-4 weeks) GFS/EU ensembles forecast show a very healthy snow cover for much of Alaska and Yukon territory with much of western and Central Canada picking up substantially also

Fantastic news!

Bgoney wrote: ↑Fri Sep 10, 2021 11:12 am

tron777 wrote: ↑Fri Sep 10, 2021 10:36 am If I remember right, mid Sept is usually the avg for when the melting process ends and the re-freezing process begins so we're pretty much right on cue there. Good news for early snow and cold air build up for sure, but as usual, the questions remain how it'll get down here. Right now, AK and Canada are going to be the beneficiaries as you would expect them to be in Sept / Oct. I like the odds still of an early start to the season. One wild card though that I am hearing talk of is another +IOD event for the upcoming winter, so we'll need to keep an eye on that. Hopefully it doesn't get out of control like a couple of winters ago.

Not to concerned with IOD being a big influence . Last I checked, a couple weeks ago it was about -.30 and expect to slowly rise to near neutral by December. So at least we know it won't be raging one way or the other going into the winter months like a couple years ago.

That year with the IOD was a huge learning experience. I knew about it but had very little knowledge until my forecast that year busted.

Bgoney wrote: ↑Fri Sep 10, 2021 11:12 am

tron777 wrote: ↑Fri Sep 10, 2021 10:36 am If I remember right, mid Sept is usually the avg for when the melting process ends and the re-freezing process begins so we're pretty much right on cue there. Good news for early snow and cold air build up for sure, but as usual, the questions remain how it'll get down here. Right now, AK and Canada are going to be the beneficiaries as you would expect them to be in Sept / Oct. I like the odds still of an early start to the season. One wild card though that I am hearing talk of is another +IOD event for the upcoming winter, so we'll need to keep an eye on that. Hopefully it doesn't get out of control like a couple of winters ago.

Not to concerned with IOD being a big influence . Last I checked, a couple weeks ago it was about -.30 and expect to slowly rise to near neutral by December. So at least we know it won't be raging one way or the other going into the winter months like a couple years ago.

In addition, wasn't the QBO also positive that winter? With it being negative this go around, that should also help to keep the IOD in check? Just a guess as I don't know if there is any relationship between the two or not.

EDIT: There is a relationship between the IOD and the MJO. It has something to do with where the MJO waves amplify or de-amplify (what phases we see most often since we know weather patterns tend to repeat themselves). A lot of this is above my head though too.

Hey, a guy can dream can't he?

Yes this would be awesome!

Wow! We haven't had an early start let alone a cold Dec in a long time. The pv is still forecast to be weak so that would help in getting the cold air to move. If the blocking is there in the right areas, we will have fun early.

Been running over wooly worms on the road for a couple weeks, this morning got my first closeup observation, black/brown/black

Bgoney wrote: ↑Sat Sep 18, 2021 7:48 am Been running over wooly worms on the road for a couple weeks, this morning got my first closeup observation, black/brown/black

Wow! That's awesome!

Found this to be interesting folks. Would lend credence to a possible weak PV and the potential for continued blocking.

tron777 wrote: ↑Mon Sep 20, 2021 7:28 pm

Found this to be interesting folks. Would lend credence to a possible weak PV and the potential for continued blocking.

I think its all in correlation with an east QBO/ Solar minimum combo , which i read, leads to more often than not a weaker PV for a good chunk of late fall early Winter. So , I think as long as the QBO behaves , I like the prospects

Bgoney wrote: ↑Tue Sep 21, 2021 7:38 am

tron777 wrote: ↑Mon Sep 20, 2021 7:28 pm

Found this to be interesting folks. Would lend credence to a possible weak PV and the potential for continued blocking.

I think its all in correlation with an east QBO/ Solar minimum combo , which i read, leads to more often than not a weaker PV for a good chunk of late fall early Winter. So , I think as long as the QBO behaves , I like the prospects

I agree great post! The Sept reading should come out for the QBO in the next week or two. Will be interesting to see if the rate of drop keeps slowing or not. With regards to the Nina... another downwelling KW should allow it to drop a bit again.

https://www.cpc.ncep.noaa.gov/products/ ... zteq.shtml

The process has begun!

Departure from normal from Univ of Rutgers:




Blue areas are positive anom. Looking good in AK and parts of Siberia. Two important places for cold air production.

Wow , Alaska really took off from where it was just a few days ago

Bgoney wrote: ↑Wed Sep 22, 2021 1:16 pm Wow , Alaska really took off from where it was just a few days ago

Barrow has over a foot of snow on the ground already and their morning temp the other day was only 6 degrees.

tron777 wrote: ↑Wed Sep 22, 2021 2:29 pm

Bgoney wrote: ↑Wed Sep 22, 2021 1:16 pm Wow , Alaska really took off from where it was just a few days ago

Barrow has over a foot of snow on the ground already and their morning temp the other day was only 6 degrees.

That is quite a bit of snow for Barrow. What I don't want to see is a huge amount of snow say in early-mid November for much of Alaska because sometimes this can lead to colder air heading towards its source which snow on the ground can be part of that equation. Not sure how much snow Barrow averages in a season but my guess maybe 30 inches.

tpweather wrote: ↑Wed Sep 22, 2021 2:59 pm

tron777 wrote: ↑Wed Sep 22, 2021 2:29 pm

Bgoney wrote: ↑Wed Sep 22, 2021 1:16 pm Wow , Alaska really took off from where it was just a few days ago

Barrow has over a foot of snow on the ground already and their morning temp the other day was only 6 degrees.

That is quite a bit of snow for Barrow. What I don't want to see is a huge amount of snow say in early-mid November for much of Alaska because sometimes this can lead to colder air heading towards its source which snow on the ground can be part of that equation. Not sure how much snow Barrow averages in a season but my guess maybe 30 inches.

Correct Tim... they don't avg a lot. Mainly cold and dry. IMO, seeing it this early is good. It promotes cold air and snow production early. As the days gets shorter and the snowpack deeper, it should begin to shift more south and east in time if the current blocking pattern continues, then it can be directed our way with any luck later. On the other hand, your point is also a distant possibility. Just depends on the 500 MB pattern as to where the cold air goes.

With the big ridge expected to develop across Eastern North America down the road, that may allow a trough for Siberia to get them caught up in the snow cover dept in early Rocktober as well. Something to monitor there.

Latest Sept Models for La Nina for the upcoming winter. IRI, ECMWF and Aussies are included here.

So far... zonal mean winds at 10 hPa weaker then normal. Good news there...

Fairbanks continues to see receive light snow... already a few inches on the ground. It's early even for them. From Anchorage:

tron777 wrote: ↑Tue Sep 28, 2021 7:10 pm Fairbanks continues to see receive light snow... already a few inches on the ground. It's early even for them. From Anchorage:

This would explain the nice and warm weather for us. Very little in the way of cool air here so far.