January/February Mid/Long Range Disco IV: A New Hope

[CAPE]

3 minutes ago, Ralph Wiggum said:

What was Chuck bazzing on about yesterday that our best chance in this N Am longwave pattern would be with a ++NAO? I tend not to read some of his stuff too deeply as it often is contradictory. Any truth to what he suggested tho? @CAPE, @psuhoffman, @WxUSAF

I missed that one lol. If we have a ++NAO, that likely means there is a +AO, so that's not favorable for cold and snow chances here. There are exceptions, like a -EPO/+PNA driven pattern, which can bring the cold but frozen events tend to be light to moderate from weaker waves, and amped systems tend to track inland or cut west.

[psuhoffman]

1 minute ago, Heisy said:

Yea, this winter every time we get a good run on the models it’s in the day 9-10+ range and gone 6 hours later. Can we get lucky one time?


.

Guidance has seasonal tendencies.  They used to be more consistent. For years the GFS was too cold and would adjust north like clockwork. The euro would cut off too often and leave energy behind. But now with constant updates these biases change year to year.  But this season guidance has made 2 key errors at day 10+.  Underestimated the SE ridge and overestimated TPV displacements.  Those 2 continuous adjustments take a pretty good day 10 look and turn it into garbage for us by day 5. 

[Siberian-Snowcover-Myth]

1 hour ago, Wonderdog said:

Boundary line makes it to the Mid Atlantic  by 2/3 and hangs around till a redevelopment occurs and moves out on 2/5. An interesting period for sure only 9 or 10 days away. 

You can likely shift that North about 500 miles. The SER will win out.

[CAPE]

22 minutes ago, Heisy said:

Yea, this winter every time we get a good run on the models it’s in the day 9-10+ range and gone 6 hours later. Can we get lucky one time?


.

But it's been clear the rest of Jan was toast minus front end slop chances for the NW crew this week. You have been honking about Feb 4-7 for days now. Well yeah, that is still 10 days out.

The ens means continue to advertise chances for early February.

[psuhoffman]

12 minutes ago, Ralph Wiggum said:

What was Chuck bazzing on about yesterday that our best chance in this N Am longwave pattern would be with a ++NAO? I tend not to read some of his stuff too deeply as it often is contradictory. Any truth to what he suggested tho? @CAPE, @psuhoffman, @WxUSAF

 

4 minutes ago, CAPE said:

I missed that one lol. If we have a ++NAO, that likely means there is a +AO, so that's not favorable for cold and snow chances here. There are exceptions, like a -EPO/+PNA driven pattern, which can bring the cold but frozen events tend to be light to moderate from weaker waves, and amped systems tend to track inland or cut west.

I hate to try to translate his “stuff” but if what he really means is we would be better off given the Nina/TNH base state if we got a TPV displaced into eastern Canada along with a +PNA (remember he is also predicting a +pna, ironically since guidance is now hinting maybe…) he is right. It’s not the greatest pattern but a “south biased” +NAO in conjunction with a pna ridge is better than anything else if we accept the N Amer thermals will struggle AND a SE ridge will try like hell no matter what. In that reality a Tpv over is suppressed the SE ridge and provides a cold source and the pna gives us a shot to keep waves under us. But the pna is the key. If the NAO goes positive and the pna stays negative we’re royally fucked. 

[CAPE]

3 minutes ago, psuhoffman said:

 

I hate to try to translate his “stuff” but if what he really means is we would be better off given the Nina/TNH base state if we got a TPV displaced into eastern Canada along with a +PNA (remember he is also predicting a +pna, ironically since guidance is now hinting maybe…) he is right. It’s not the greatest pattern but a “south biased” +NAO in conjunction with a pna ridge is better than anything else if we accept the N Amer thermals will struggle AND a SE ridge will try like hell no matter what. In that reality a Tpv over is suppressed the SE ridge and provides a cold source and the pna gives us a shot to keep waves under us. But the pna is the key. If the NAO goes positive and the pna stays negative we’re royally fucked. 

Didn't realize he was predicting a +PNA. That's a switch lol. But yeah we shall see if the hints on the latest guidance of a +PNA is a mirage. If that's real, the mid month period might be workable. Most extended products have the NAO trending towards neutral/negative just after mid month fwiw.

[psuhoffman]

I made a really long post about this in my “other” thread yesterday but this is totally about a cyclical pattern not AGW so I’m repeating the cliffs notes version here and y’all can deal with it. 

It seems we’ve transitioned into a -PDO regime. The last long term -PDO was from 1945-1981.  If true we can expect the pna to be “hostile” the vast majority of the time the next 30-40 years. If you look back at 1945-1981 the way we overcame that was mostly one thing. Blocking blocking blocking.  A -NAO would suppress the attempted SER and lead to a broad mid latitude trough coast to coast under the block.  Here is the h5 for 6” snows at bwi during that period. 

Keep in mind that uses 1990-2020 climo so the blue is exaggerated due to todays warmer normals. but you can see the longwave pattern. 
 

Note there the pna is still negative but not crazy negative.  The path to snow during our last -pdo was to time up less hostile pac periods with a -NAO.  
 

The problem is our last 4 blocks failed totally for the same reason, it just wasn’t cold enough.  That has nothing to do with the pac.  It’s rare to get a NAO block AND a big epo ridge.  Those 2 have a negative correlation.  A -NAO was how we overcame a bad pac from 1945-1981 so when we get blockinF fails and ppl say “but the pac” I roll my eyes because the pac is going to be utter garbage the next 35 years, the NAO is supposed to be how we offset it.  The positive NAO periods during the last -pdo cycle were awful by that periods standards. But the -NAO periods were very snowy DESPITE the pacific. 

[jayyy]

Not concerned about exactly placement of digital blue at this range, but the Latest GFS tracks two consecutive storms south of us next week.

Verbatim.. Wave 1 is rain and brings the boundary south enough to get us some snow out of wave 2. However, the biggest seasonal trend of underestimating the SER would very likely kill chance 2 also if this exact scenario were to play out. Wave 3? It’s an amped cutter.

Obviously it’s an OP run, long range, and will change, but nothing about this run excites me. All I see are a ton of ways to fail.

[Wonderdog]

44 minutes ago, psuhoffman said:

This tells the story 

 

But it used to be 12/13 days ago. 

[psuhoffman]

I want this to be “real” as much as anyone. But as the “window” starts to broach day 10 I see the same trends with every other threat period all year. 
 

24 hour trend on gefs for the 7 day snowfall centered on our period of interest. 

Hopefully today we bounce back. 

[jayyy]

GEFS/GEPS around the 10th says the SER pumps to kingdom come. 540 line up to nearly Canada.

Guess there’s some time for things to adjust but yeesh, we can’t get anything more than a 5 day window for snow these days and that window is looking progressively worse for the first week of February.

Hopefully the mid to late month flip CAPE has been talking about is legit.


.

[brooklynwx99]

3 minutes ago, psuhoffman said:

I want this to be “real” as much as anyone. But as the “window” starts to broach day 10 I see the same trends with every other threat period all year. 
 

24 hour trend on gefs for the 7 day snowfall centered on our period of interest. 

Hopefully today we bounce back. 

that's just one ensemble run, though. the 00z GEFS looked good, as did all of the other ensemble means at 00z. there are going to be fluctuations, but the general look has remained very consistent

[psuhoffman]

6 minutes ago, Wonderdog said:

But it used to be 12/13 days ago. 

That threat was. But before that we were looking at the Feb 1 wave and before that the Jan 28 wave and before that Jan 25 was the one.  For the last month every wave looked good day 10-15 then trended to the same garbage by day 7. Some because the track. Some took a perfect track and we’re just too warm. But it’s been the same dance for weeks. 
 

Now eventually one of these will break through and become a real threat. I mean I hope so otherwise we will never snow again lol. But given the constant head fakes all season I’ll continue to be skeptical until it’s inside day 7. 

[psuhoffman]

1 minute ago, brooklynwx99 said:

that's just one ensemble run, though. the 00z GEFS looked good, as did all of the other ensemble means at 00z. there are going to be fluctuations, but the general look has remained very consistent

0z looked better than 6z but slightly worse than yesterdays 12z. Maybe it’s a bounce but it’s bouncing subtly the same direction everything else has, the wrong way. Look I hope you’re right and this is different. I’m just skeptical.  

[Terpeast]

25 minutes ago, psuhoffman said:

I made a really long post about this in my “other” thread yesterday but this is totally about a cyclical pattern not AGW so I’m repeating the cliffs notes version here and y’all can deal with it. 

It seems we’ve transitioned into a -PDO regime. The last long term -PDO was from 1945-1981.  If true we can expect the pna to be “hostile” the vast majority of the time the next 30-40 years. If you look back at 1945-1981 the way we overcame that was mostly one thing. Blocking blocking blocking.  A -NAO would suppress the attempted SER and lead to a broad mid latitude trough coast to coast under the block.  Here is the h5 for 6” snows at bwi during that period. 

Keep in mind that uses 1990-2020 climo so the blue is exaggerated due to todays warmer normals. but you can see the longwave pattern. 
 

Note there the pna is still negative but not crazy negative.  The path to snow during our last -pdo was to time up less hostile pac periods with a -NAO.  
 

The problem is our last 4 blocks failed totally for the same reason, it just wasn’t cold enough.  That has nothing to do with the pac.  It’s rare to get a NAO block AND a big epo ridge.  Those 2 have a negative correlation.  A -NAO was how we overcame a bad pac from 1945-1981 so when we get blockinF fails and ppl say “but the pac” I roll my eyes because the pac is going to be utter garbage the next 35 years, the NAO is supposed to be how we offset it.  The positive NAO periods during the last -pdo cycle were awful by that periods standards. But the -NAO periods were very snowy DESPITE the pacific. 

Okay this is interesting because the 1960s were insane - why? Was that a window when the pac temporarily become more favorable combined with a -nao? Or did the 1960s do well DESPITE a hostile pac? Was there some other factor involved other than the nao?

[CAPE]

46 minutes ago, Terpeast said:

Okay this is interesting because the 1960s were insane - why? Was that a window when the pac temporarily become more favorable combined with a -nao? Or did the 1960s do well DESPITE a hostile pac? Was there some other factor involved other than the nao?

Low solar and many -NAO years that decade. I did a year by year analysis of the h5 composites and many of those winters were impressively cold in the midlatitudes- some Nina, some Nino, some Neutral. Some of those looks.. just hard to imagine seeing them today.

[anotherman]

3 minutes ago, CAPE said:

Low solar and many -NAO years that decade. I did a year by year analysis of the h5 composites and many of those winters were impressively cold in the midlatitudes- some Nina, Some Nino, some Neutral. Some of those looks.. just hard to imagine seeing them today.

Question....why do we still use analogs from 30+ years ago?

[Maestrobjwa]

1 hour ago, CAPE said:

Didn't realize he was predicting a +PNA. That's a switch lol. But yeah we shall see if the hints on the latest guidance of a +PNA is a mirage. If that's real, the mid month period might be workable. Most extended products have the NAO trending towards neutral/negative just after mid month fwiw.

Speaking of that...am I hallucinating or have the GEFS and EPS been trying to pop a temporary + PNA in our little window next weekend (that is the 3rd-5th)?

Also...I seem to recall some previous analogs that indicated that heavy blocking in December correlated to it's return sometime later that winter. Of course, who knows if analogs still work anymore, lol...but just wondering.

[IronTy]

2 minutes ago, anotherman said:

Question....why do we still use analogs from 30+ years ago?

Ask Joe Bastardi.  

[MDScienceTeacher]

1 hour ago, psuhoffman said:

I made a really long post about this in my “other” thread yesterday but this is totally about a cyclical pattern not AGW so I’m repeating the cliffs notes version here and y’all can deal with it. 

It seems we’ve transitioned into a -PDO regime. The last long term -PDO was from 1945-1981.  If true we can expect the pna to be “hostile” the vast majority of the time the next 30-40 years. If you look back at 1945-1981 the way we overcame that was mostly one thing. Blocking blocking blocking.  A -NAO would suppress the attempted SER and lead to a broad mid latitude trough coast to coast under the block.  Here is the h5 for 6” snows at bwi during that period. 

Keep in mind that uses 1990-2020 climo so the blue is exaggerated due to todays warmer normals. but you can see the longwave pattern. 
 

Note there the pna is still negative but not crazy negative.  The path to snow during our last -pdo was to time up less hostile pac periods with a -NAO.  
 

The problem is our last 4 blocks failed totally for the same reason, it just wasn’t cold enough.  That has nothing to do with the pac.  It’s rare to get a NAO block AND a big epo ridge.  Those 2 have a negative correlation.  A -NAO was how we overcame a bad pac from 1945-1981 so when we get blockinF fails and ppl say “but the pac” I roll my eyes because the pac is going to be utter garbage the next 35 years, the NAO is supposed to be how we offset it.  The positive NAO periods during the last -pdo cycle were awful by that periods standards. But the -NAO periods were very snowy DESPITE the pacific. 

QQ.. NOA describes PDO as such:

When SSTs are anomalously cool in the interior North Pacific and warm along the Pacific Coast, and when sea level pressures are below average over the North Pacific, the PDO has a positive value. 

What is the interior North Pacific.. also how does one visualize PDO?  Like If I were to pick a plot on TT in a region to see the PDO anomaly, what would I look at?

[psuhoffman]

25 minutes ago, anotherman said:

Question....why do we still use analogs from 30+ years ago?

because that's when it snowed 

[psuhoffman]

53 minutes ago, Terpeast said:

Okay this is interesting because the 1960s were insane - why? Was that a window when the pac temporarily become more favorable combined with a -nao? Or did the 1960s do well DESPITE a hostile pac? Was there some other factor involved other than the nao?

This is the H5 composite for Dec-Mar for the entire 1960s. 

Looks like the dominant features were the -NAO but also an atrocious PAC with a dominant Aleutian ridge -PNA.  But the obvious, even if you adjust for the fact that is using today's climo which skews everything towards the blue...is the fact the mid latitudes were simply colder everywhere.  

Here are the snowiest periods of the period 

March 1960

Dec 1961

Feb to Mar 1962

Jan to Mar 1964

Jan 1966

Look at the pacific on all those!!!  

But it wasn't just the 60s.  There wasn't nearly as much snow in the 50's and 70's because the NAO was predominantly positive...but if we look at the snowy periods during those periods we see the same thing...the NAO overcoming the pacific.  

1979

Yes there were some exceptions where we got the PDO to go temporarily positive like 1961 or 1978 and those were good years also... but the PDO was negative 80% of the time from 1945 to 1981 and yet we still managed to average significantly more snow during that period than we have since when the PDO averaged positive 72% of the time.  

I have some thoughts on possible reasons "why", some AGW and some not, but perhaps we should continue that over in the other thread to avoid the shitstorm that would result here... but this is why I keep harping on the idea WE HAVE TO BE ABLE TO SNOW IN FLAWED PAC PATTERNS.  Look at the pac during those snowy periods above.  If we are in fact entering a long term -PDO cycle THAT IS HOW IT HAS TO SNOW!!!  The pac is probably very rarely going to look the way it did most of the more recent past with some huge epo/pna ridge.  That was almost NEVER the winter base state during the last -PDO period.  But that is not a valid excuse for no snow because we got plenty of snow in the last -PDO, we just had to overcome the awful pac pattern with other factors.  

[Terpeast]

4 minutes ago, psuhoffman said:

This is the H5 composite for Dec-Mar for the entire 1960s. 

Looks like the dominant features were the -NAO but also an atrocious PAC with a dominant Aleutian ridge -PNA.  But the obvious, even if you adjust for the fact that is using today's climo which skews everything towards the blue...is the fact the mid latitudes were simply colder everywhere.  

Here are the snowiest periods of the period 

March 1960

Dec 1961

Feb to Mar 1962

Jan to Mar 1964

Jan 1966

Look at the pacific on all those!!!  

But it wasn't just the 60s.  There wasn't nearly as much snow in the 50's and 70's because the NAO was predominantly positive...but if we look at the snowy periods during those periods we see the same thing...the NAO overcoming the pacific.  

1979

Yes there were some exceptions where we got the PDO to go temporarily positive like 1961 or 1978 and those were good years also... but the PDO was negative 80% of the time from 1945 to 1981 and yet we still managed to average significantly more snow during that period than we have since when the PDO averaged positive 72% of the time.  

I have some thoughts on possible reasons "why", some AGW and some not, but perhaps we should continue that over in the other thread to avoid the shitstorm that would result here... but this is why I keep harping on the idea WE HAVE TO BE ABLE TO SNOW IN FLAWED PAC PATTERNS.  Look at the pac during those snowy periods above.  If we are in fact entering a long term -PDO cycle THAT IS HOW IT HAS TO SNOW!!!  The pac is probably very rarely going to look the way it did most of the more recent past with some huge epo/pna ridge.  That was almost NEVER the winter base state during the last -PDO period.  But that is not a valid excuse for no snow because we got plenty of snow in the last -PDO, we just had to overcome the awful pac pattern with other factors.  

Really informative, thanks for putting this together. Busy day at work today, but if I could add some of my thoughts to this, I’ll do it in the other thread. Thanks again. 

[mattie g]

54 minutes ago, anotherman said:

Question....why do we still use analogs from 30+ years ago?

Because there's no way to reliably provide a long-term "forecast" without looking back at the historical data to see how things played out during periods with similar teleconnections. It would basically be impossible.

[Daniel Boone]

44 minutes ago, psuhoffman said:

This is the H5 composite for Dec-Mar for the entire 1960s. 

Looks like the dominant features were the -NAO but also an atrocious PAC with a dominant Aleutian ridge -PNA.  But the obvious, even if you adjust for the fact that is using today's climo which skews everything towards the blue...is the fact the mid latitudes were simply colder everywhere.  

Here are the snowiest periods of the period 

March 1960

Dec 1961

Feb to Mar 1962

Jan to Mar 1964

Jan 1966

Look at the pacific on all those!!!  

But it wasn't just the 60s.  There wasn't nearly as much snow in the 50's and 70's because the NAO was predominantly positive...but if we look at the snowy periods during those periods we see the same thing...the NAO overcoming the pacific.  

1979

Yes there were some exceptions where we got the PDO to go temporarily positive like 1961 or 1978 and those were good years also... but the PDO was negative 80% of the time from 1945 to 1981 and yet we still managed to average significantly more snow during that period than we have since when the PDO averaged positive 72% of the time.  

I have some thoughts on possible reasons "why", some AGW and some not, but perhaps we should continue that over in the other thread to avoid the shitstorm that would result here... but this is why I keep harping on the idea WE HAVE TO BE ABLE TO SNOW IN FLAWED PAC PATTERNS.  Look at the pac during those snowy periods above.  If we are in fact entering a long term -PDO cycle THAT IS HOW IT HAS TO SNOW!!!  The pac is probably very rarely going to look the way it did most of the more recent past with some huge epo/pna ridge.  That was almost NEVER the winter base state during the last -PDO period.  But that is not a valid excuse for no snow because we got plenty of snow in the last -PDO, we just had to overcome the awful pac pattern with other factors.  

The thing that's been missing recently is the 50-50.  Imo, there's your main difference maker.

[Terpeast]

2 minutes ago, Daniel Boone said:

The thing that's been missing recently is the 50-50.  Imo, there's your main difference maker.

And for that, we have to kill the SER/WAR. As long as that is there, it’s very hard to lock in a 50/50

[psuhoffman]

10 minutes ago, Daniel Boone said:

The thing that's been missing recently is the 50-50.  Imo, there's your main difference maker.

 

7 minutes ago, Terpeast said:

And for that, we have to kill the SER/WAR. As long as that is there, it’s very hard to lock in a 50/50

This is correct in that we have had a couple blocks recently where there was no response in the mid latitude Atlantic under it. That’s troubling. But what’s more troubling are these 2 recent blocking episodes where we did get the 50/50 and it still made no difference. 

and yea the pac wasn’t good…but back to my point about the pdo, if that’s going to be the pac base state 80% of the time for the foreseeable future we can’t afford to just say “the pac”. We have to look at how we overcame that look in the past. What troubles me in the last 4 times we got blocking recently…it didn’t work!  
I am in the process of compiling data to see what the % of times we got snow in a -NAO -PDO month during the last -pdo cycle and see what the success rate was to see if our recent -NAO fails are typical or a red flag. But I have to do some real work so I’ll get to that later. 

[LP08]

GFS is closer next Wednesday with better confluence up top.

[WxUSAF]

2 minutes ago, LP08 said:

GFS is closer next Wednesday with better confluence up top.

With a lot of juice on its tail and arctic air pressing…

[SnowenOutThere]

2 minutes ago, WxUSAF said:

With a lot of juice on its tail and arctic air pressing…