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Winter 2015-16 Medium-Long Range Discussion


OHweather

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It's encouraging. I would really like a front loaded winter.

 

Watch el nino fears go right down the toilet when the trough sets up as it has the last few years.

Can't wait to get front loaded winters again... I want to get all the cold out of the way early in the winter. I want a legit Spring... kinda like this year. This Spring wasn't great, but it was much better than the crappy 2013 and 14.

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I endorse this post. 

 

I vehemently do not endorse this.

 

It's like groundhog's day with the winter patterns lately (consistently bittery cold/dry NW flow).

 

it's clearly been too much to ask for closed 995mb lows and negative tilt troughs over Indianapolis and Cleveland with impressive trowals.

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Can't wait to get front loaded winters again... I want to get all the cold out of the way early in the winter. I want a legit Spring... kinda like this year. This Spring wasn't great, but it was much better than the crappy 2013 and 14.

 

I'd be fine with a good DJF and blow torch March starting March 1st.

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404 error, does not compute.

Hey, I said "kinda" like this year :P March could've been much warmer, but April and May weren't bad. May was very active. 

 

Then again, you're in extreme SW Canada, so we're used to completely different things

 

 

I'd be fine with a good DJF and blow torch March starting March 1st.

I'd be happy with any winter as long as we have a warm/active Spring

 

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Ok, so maybe 3 or 4 people tops in the entire subforum would get enjoyment out of that ugliness.

 

I agree.

 

We have these massive snowguns surrounding the subforum, but most of us live in the wrong spots.

 

I remember getting mad at my parents as a kid once I realized we lived on the wrong side of the state. LOL.

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I agree.

 

We have these massive snowguns surrounding the subforum, but most of us live in the wrong spots.

 

I remember getting mad at my parents as a kid once I realized we lived on the wrong side of the state. LOL.

 

Got a good laugh after reading that! :lmao:

As far as my state, I feel I live in the right spot. :D

Bo is the #1 person that would benefit from a giant broad trough over the Great Lakes.

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Latest post from Judah Cowen, some high level stuff in here, but things are looking much better.

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

The polar cap geopotential height anomaly plot continues to show a strong polar vortex into the foreseeable future (not shown). However some slight increase in wave activity flux in week two is predicted to perturb the stratospheric polar vortex so that it becomes less circular and more elongated (Figure 7). The counter clockwise flow around the polar vortex would help transport cold air from Siberia and drive it into North America east of the Rockies. This pattern is reminiscent of the dominant winter pattern of the past two winters that resulted in extremely cold winters in the eastern United States. The possibility of transport of cold air from Siberia into the Central and Eastern United States is something to watch as we officially begin winter. However we do not anticipate this to necessarily be the dominant winter pattern as we expect further disturbing of the polar vortex and longer term implications as we discuss in the next section.

30–day

As we have shown in our research the favored high latitude atmospheric pattern in November that follows above normal October Eurasian snow cover extent is the expansion of the Siberian high across northwest Asia with low pressure to the east near the Aleutians and a secondary area of low pressure in the northern North Atlantic; a pattern that we refer to as the tripole pattern (Cohen and Jones (2012)). The current atmospheric pattern strongly projects onto this pattern. This same pattern also favors the increase in wave activity flux or the vertical transfer of energy from the troposphere to the stratosphere during the month of December. At AER we have developed a polar vortex model that predicts the strength of the polar vortex one month in advance. It is predicting a major sudden stratospheric warming (SSW) in mid-December. We currently feel that this forecast is unlikely because the model is overly sensitive to SSW and has many false positives and because a major SSW is relatively rare in December. Still given the polar vortex model forecast and strong projection of the current atmospheric pattern onto the tripole pattern, we are more confident in increased wave activity flux in December that will result in weakening of the polar vortex in December and likely continuing into January. Also because the current dominant high latitude circulation is a wave two pattern, this would favor a polar vortex split relative to a polar vortex displacement in the event of a significant weakening of the polar vortex. One inhibiting background factor is the westerly phase of the quasi-biennial oscillation (QBO) that favors a strong vortex over a weak vortex. But if our expectations of a weakened polar vortex verify, this will likely favor an increased likelihood of severe winter weather across the continents of the Northern Hemisphere. Of course all of this is highly speculative but the purpose of this blog is to push the boundaries of what is possible in weather forecasting beyond the skillful range of the weather models.

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Increasing WAF could make things interesting heading into January in terms of a PV displacement or the like.  His mention of the +QBO is important.  It is an effective layer of protection for the PV...obviously not an impenetrable one though.

 

I like how he says their model predicts an SSW in Dec and then says he doesn't believe the model because it's wrong all the time :lmao:

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Latest post from Judah Cowen, some high level stuff in here, but things are looking much better.

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

The polar cap geopotential height anomaly plot continues to show a strong polar vortex into the foreseeable future (not shown). However some slight increase in wave activity flux in week two is predicted to perturb the stratospheric polar vortex so that it becomes less circular and more elongated (Figure 7). The counter clockwise flow around the polar vortex would help transport cold air from Siberia and drive it into North America east of the Rockies. This pattern is reminiscent of the dominant winter pattern of the past two winters that resulted in extremely cold winters in the eastern United States. The possibility of transport of cold air from Siberia into the Central and Eastern United States is something to watch as we officially begin winter. However we do not anticipate this to necessarily be the dominant winter pattern as we expect further disturbing of the polar vortex and longer term implications as we discuss in the next section.

30–day

As we have shown in our research the favored high latitude atmospheric pattern in November that follows above normal October Eurasian snow cover extent is the expansion of the Siberian high across northwest Asia with low pressure to the east near the Aleutians and a secondary area of low pressure in the northern North Atlantic; a pattern that we refer to as the tripole pattern (Cohen and Jones (2012)). The current atmospheric pattern strongly projects onto this pattern. This same pattern also favors the increase in wave activity flux or the vertical transfer of energy from the troposphere to the stratosphere during the month of December. At AER we have developed a polar vortex model that predicts the strength of the polar vortex one month in advance. It is predicting a major sudden stratospheric warming (SSW) in mid-December. We currently feel that this forecast is unlikely because the model is overly sensitive to SSW and has many false positives and because a major SSW is relatively rare in December. Still given the polar vortex model forecast and strong projection of the current atmospheric pattern onto the tripole pattern, we are more confident in increased wave activity flux in December that will result in weakening of the polar vortex in December and likely continuing into January. Also because the current dominant high latitude circulation is a wave two pattern, this would favor a polar vortex split relative to a polar vortex displacement in the event of a significant weakening of the polar vortex. One inhibiting background factor is the westerly phase of the quasi-biennial oscillation (QBO) that favors a strong vortex over a weak vortex. But if our expectations of a weakened polar vortex verify, this will likely favor an increased likelihood of severe winter weather across the continents of the Northern Hemisphere. Of course all of this is highly speculative but the purpose of this blog is to push the boundaries of what is possible in weather forecasting beyond the skillful range of the weather models.

1200z GFS ensemble at 246 hours has a nice high pressure ridge from northeast Russia to the predicted blocking high over Alaska.

 This ridgeing  would result in strong heatflux from the troposphere to the stratosphere that weakens the stratosphere polar vortex and that makes possibler SSW events. later in the winter.If that occrs as is mentioed by Cohen in his blog you get a solid -AO and things get interesting.

 

   That ridging also makes for two wave pattern that usually makes for decent cold in eastern North America.

 

  Of course El Nino may over ride all of this but we will try not to think about that .

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1200z GFS ensemble at 246 hours has a nice high pressure ridge from northeast Russia to the predicted blocking high over Alaska.

 This ridgeing  would result in strong heatflux from the troposphere to the stratosphere that weakens the stratosphere polar vortex and that makes possibler SSW events. later in the winter.If that occrs as is mentioed by Cohen in his blog you get a solid -AO and things get interesting.

 

   That ridging also makes for two wave pattern that usually makes for decent cold in eastern North America.

 

  Of course El Nino may over ride all of this but we will try not to think about that .

 

I suspect this will be the winter, (at least early on), where a lot of long range cold patterns showing up on the models will fail to realize in evolution, duration, and depth.  Of course northwestern areas of the subforum are a different story than where I sit.

 

Just a hunch wrapped in a super-sized el nino.    

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I suspect this will be the winter, (at least early on), where a lot of long range cold patterns showing up on the models will fail to realize in evolution, duration, and depth.  Of course northwestern areas of the subforum are a different story than where I sit.

 

Just a hunch wrapped in a super-sized el nino.    

 

Agree with this.

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I feel the roller coaster concept might breed a few more ice storms...or at least the potential ... If any legit snowpack can be put down (even if short term snowpacks)...especially if we maintain any of these mega transport feed scenarios into winter

I've been thinking the same thing with the Ice Storm threat being a bit higher this year then usual

Sent from my iPhone using Tapatalk

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yeah...was just gonna say GFS has it too and agree Jonger...via the GFS and Canadian it looks like the warmth is a relatively quick shot (which we'll see what that even translates to with a new snowpack down)...then back to normal or slightly below normal temps

 

 

As long as the pattern features high amplitude rossby waves during the seasonal transition, these wild swings are going to happen.

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