December Mid/Long Range Discussion

[nj2va]

Don’t mean to interrupt the CC talk, but nice to see the ensembles continue to suggest the pattern flips more favorable in the lead up to Christmas with ridging along the west coast.  

[cbmclean]

  On 12/6/2023 at 4:04 AM, nj2va said:

Don’t mean to interrupt the CC talk, but nice to see the ensembles continue to suggest the pattern flips more favorable in the lead up to Christmas with ridging along the west coast.  

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I haven't been looking at them in detail the last several days; would you say the transition is continuing to move up in time, or is it always at day 15?

[Weather Will]

WB 0Z EURO for Sunday/Monday.  Maybe some conversational snow east of the mountains? Something to watch at 5 days.

[psuhoffman]

Terpeast was transparent with his methodology and the limitations. It’s very valid to point out that the entire storm track could be altered. But it’s impossible to assess that through data analysis. We would need a very sophisticated simulation. However I would argue it’s highly unlikely such changes would end up being a net positive simply because the net impact of warming overall would be to adjust everything north on the whole and average snow decreases as you go south of us. 

[Weather Will]

  On 12/6/2023 at 9:27 AM, psuhoffman said:

Terpeast was transparent with his methodology and the limitations. It’s very valid to point out that the entire storm track could be altered. But it’s impossible to assess that through data analysis. We would need a very sophisticated simulation. However I would argue it’s highly unlikely such changes would end up being a net positive simply because the net impact of warming overall would be to adjust everything north on the whole and average snow decreases as you go south of us. 

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You should take your own advice, be positive.  Happy Hump Day!

[CAPE]

Both the 0z and 6z GFS have a coastal low for the mid month window with snow for parts of the area. Indications are there on the 0z Ens runs. Again the advertised pattern isn't ideal esp in the NA so really good timing would be needed to get a High positioned to the N/NW for a feed of cold into a storm. Way out there but something to monitor.

 

[psuhoffman]

  On 12/6/2023 at 9:43 AM, Weather Will said:

You should take your own advice, be positive.  Happy Hump Day!

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What I said wasn’t positive or negative. Just facts. 

[Terpeast]

  On 12/6/2023 at 9:27 AM, psuhoffman said:

Terpeast was transparent with his methodology and the limitations. It’s very valid to point out that the entire storm track could be altered. But it’s impossible to assess that through data analysis. We would need a very sophisticated simulation. However I would argue it’s highly unlikely such changes would end up being a net positive simply because the net impact of warming overall would be to adjust everything north on the whole and average snow decreases as you go south of us. 

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Thanks, psu. I was kinda surprised at the reaction. Maybe they forgot about that analysis I did a few months ago. And yes we’d need modeling resources if we really wanted to dynamically simulate what a past storm would like today, but we don’t have those resources. 

Anyway, back to our regularly scheduled tracking…

[psuhoffman]

  On 12/6/2023 at 10:57 AM, CAPE said:

Both the 0z and 6z GFS have a coastal low for the mid month window with snow for parts of the area. Indications are there on the 0z Ens runs. Again the advertised pattern isn't ideal esp in the NA so really good timing would be needed to get a High positioned to the N/NW for a feed of cold into a storm. Way out there but something to monitor.

 

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Unless there are significant changes it will be very difficult for anything to start as snow given the North Atlantic setup. But it could be the type of setup where we could get some snow on the back end if things were to evolve in our favor. 

[CAPE]

  On 12/6/2023 at 1:20 PM, psuhoffman said:

Unless there are significant changes it will be very difficult for anything to start as snow given the North Atlantic setup. But it could be the type of setup where we could get some snow on the back end if things were to evolve in our favor. 

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Yeah its not a favorable NA look on a smoothed mean 10+ days out, but the last 2 runs of the GFS op showed a couple ways it could work with good wave timing setting up transient HP and/or 50-50 from a predecessor low.

[CAPE]

Latest Euro weeklies have some drool worthy h5 looks for January.

[Ji]

  On 12/6/2023 at 2:41 PM, CAPE said:

Latest Euro weeklies have some drool worthy h5 looks for January.

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looks like the seasonal runs too. The season models/weeklies have been really consistent. Although they may be too warm for December? maybe...maybe not

 

 

[psuhoffman]

  On 12/6/2023 at 2:41 PM, CAPE said:

Latest Euro weeklies have some drool worthy h5 looks for January.

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Almost all the NWP guidance looks pretty darn sweet for the second half of winter, at least.  The only small bit of reservation I have left is that guidance showed this look consistently in 2019 but the pacific remained stubborn and it never became a reality.  It was constantly a day 10+ tease.  I will feel a lot better when we start to see the pacific actually respond to the +enso and it's not just on super long range guidance.  Obviously that is not an issue yet as it's still too soon but I will be nervous if we start to see the evolution that is currently showing up around Dec 20th start to get can kicked.  

[poolz1]

If anything, Sunday looks like an interesting weather day.  A few GEFS and EPS members look like the Euro op.  Obviously, a long shot and probably not many interested in cold chasing warm especially east of the BR.  But hopefully this storm at least marks the end of our boring weather streak.

[Scraff]

  On 12/6/2023 at 2:41 PM, CAPE said:

Latest Euro weeklies have some drool worthy h5 looks for January.

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Looks eerily similar to someones avatar. If those looks continue to look stronger in time, might want to change the avatar to a bottle of DogFish Head 120 Min IPA. 

[Eskimo Joe]

  On 12/6/2023 at 2:47 PM, Ji said:

looks like the seasonal runs too. The season models/weeklies have been really consistent. Although they may be too warm for December? maybe...maybe not

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The GOA low is just too far east and continues to flood our source region with pacific puke.

[CAPE]

  On 12/6/2023 at 3:35 PM, Scraff said:

Looks eerily similar to someones avatar. If those looks continue to look stronger in time, might want to change the avatar to a bottle of DogFish Head 120 Min IPA. 

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I was wondering if anyone would notice. And not a bad idea. Utopias barrel aged version ofc.

[Eskimo Joe]

  On 12/6/2023 at 4:01 PM, CAPE said:

I was wondering if anyone would notice. And not a bad idea. Utopias barrel aged version ofc.

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Nothing wrong with a Spatan Lager or Oktoberfest.

[WxUSAF]

  On 12/6/2023 at 2:59 PM, psuhoffman said:

Almost all the NWP guidance looks pretty darn sweet for the second half of winter, at least.  The only small bit of reservation I have left is that guidance showed this look consistently in 2019 but the pacific remained stubborn and it never became a reality.  It was constantly a day 10+ tease.  I will feel a lot better when we start to see the pacific actually respond to the +enso and it's not just on super long range guidance.  Obviously that is not an issue yet as it's still too soon but I will be nervous if we start to see the evolution that is currently showing up around Dec 20th start to get can kicked.  

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I think we’re already seeing some “anti-cankicking” though. Next week has a notable +PNA now and GEFS and EPS have way reduced the amount of time with AN heights for our area. 

[psuhoffman]

  On 12/6/2023 at 3:58 PM, Eskimo Joe said:

The GOA low is just too far east and continues to flood our source region with pacific puke.

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It doesn't have to retrograde much to be in a position that has worked just fine in the past.  

We got 2 HECS during this...

And look at our source regions during that period...its torched.

Those storms all came from domestic cold with a perfect STJ storm track while Canada was mild.  At day 10 the guidance even indicated there would be temperature issues for both storms... at one point the GFS showed a perfect track slop storm when it was still over a week out.  It adjusted to be a little colder as it got closer...same as 2016, remember when at day 10 the euro and GFS has temp issues with that storm also despite a perfect track.  

Now this equation won't work in December.  It used to, if you go back before the 1980's there are examples of December snowstorms without a perfect pacific.  But accepting those days are gone...in the last 30 years pretty much every Pre Xmas snowstorm has come via a perfectly placed EPO/PNA combo ridge.  

But I wanted to point out that later in winter that look has and should work...but as I said earlier, while its worked and that look has been responsible for our snowiest periods in history...it was never all that cold, worked with domestic home grown cold absent any true arctic air, and leaves very little wiggle room to still work if you warm the whole profile very much.  I have bet my winter forecast on this equation still working...that we have not yet reached the point where warming has made domestic cold no longer an option for snow.  Let's hope that is correct.  

[Eskimo Joe]

  On 12/6/2023 at 4:56 PM, psuhoffman said:

It doesn't have to retrograde much to be in a position that has worked just fine in the past.  

We got 2 HECS during this...

And look at our source regions during that period...its torched.

Those storms all came from domestic cold with a perfect STJ storm track while Canada was mild.  At day 10 the guidance even indicated there would be temperature issues for both storms... at one point the GFS showed a perfect track slop storm when it was still over a week out.  It adjusted to be a little colder as it got closer...same as 2016, remember when at day 10 the euro and GFS has temp issues with that storm also despite a perfect track.  

Now this equation won't work in December.  It used to, if you go back before the 1980's there are examples of December snowstorms without a perfect pacific.  But accepting those days are gone...in the last 30 years pretty much every Pre Xmas snowstorm has come via a perfectly placed EPO/PNA combo ridge.  

But I wanted to point out that later in winter that look has and should work...but as I said earlier, while its worked and that look has been responsible for our snowiest periods in history...it was never all that cold, worked with domestic home grown cold absent any true arctic air, and leaves very little wiggle room to still work if you warm the whole profile very much.  I have bet my winter forecast on this equation still working...that we have not yet reached the point where warming has made domestic cold no longer an option for snow.  Let's hope that is correct.  

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Thanks for the insight. Appreciate it. I understand the GOA low is a permanent feature, just don't like the placement.

[WinterWxLuvr]

Not really long range but it was good to see a clipper type system and for it to be a decent precip producer. It was just a little too warm leading in or that woulda been a nice snow here last night.

[Maestrobjwa]

  On 12/6/2023 at 5:03 PM, WinterWxLuvr said:

Not really long range but it was good to see a clipper type system and for it to be a decent precip producer. It was just a little too warm leading in or that woulda been a nice snow here last night.

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Definitely. And again, this is the first clipper we've seen since what...2015? Lol

[psuhoffman]

  On 12/6/2023 at 4:59 PM, Eskimo Joe said:

Thanks for the insight. Appreciate it. I understand the GOA low is a permanent feature, just don't like the placement.

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Ideally we would like to see it retro a bit further west...but by day 15 its already not far off from the snowy analogs to this winter.  Below are the snowy periods from 3 of the analogs.  

1966

1964 

1987

[Stormchaserchuck1]

This is a strong 11-15 day signal for +EPO on the 6z GEFS. 

https://ibb.co/sq5tH7X

We haven't had any snow in stronger +EPO I think for at least the last 5-6 years.  Looking for the model to change (it's been in flux more than average this year), or for that AK trough to become +PNA in the time after... but we likely won't see any snow for the next 15-16 days after today. That can also be a very warm pattern as it evolves.

[Ralph Wiggum]

  On 12/6/2023 at 4:03 PM, Eskimo Joe said:

Nothing wrong with a Spatan Lager or Oktoberfest.

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What's with you guys and the light-ish hoppy beers?

Rasputin Imperial Stout....don't need the fridge.

[Daniel Boone]

  On 12/6/2023 at 5:16 PM, Stormchaserchuck1 said:

This is a strong 11-15 day signal for +EPO on the 6z GEFS. 

https://ibb.co/sq5tH7X

We haven't had any snow in stronger +EPO I think for at least the last 5-6 years.  Looking for the model to change (it's been in flux more than average this year), or for that AK trough to become +PNA in the time after... but we likely won't see any snow for the next 15-16 days after today. That can also be a very warm pattern as it evolves.

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If correct, yeah odds favor what you mentioned of what the consensus has been forecasting for that time frame really. However, we have seen things go against the grain recently. Maybe one of the time's we go back to before the last 5-6 year's. Just a little positive thought. 

[WxUSAF]

Euro ends the weekend rain storm as accumulating snow for N/W crew again.

[aldie 22]

  On 12/6/2023 at 6:29 PM, WxUSAF said:

Euro ends the weekend rain storm as accumulating snow for N/W crew again.

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I thought the GFS sorta looked that way as well and was a ton of rain prior

[TSSN+]

  On 12/6/2023 at 6:29 PM, WxUSAF said:

Euro ends the weekend rain storm as accumulating snow for N/W crew again.

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Ya the euro is um interesting… lol