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September 2016 Observations and Model Discussion for the Pacific Northwest


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OT, but every single GEFS member depicts a hurricane plowing into the Caribbean and/or Gulf in the extended range. Maybe this is something to watch (could have implications on the pattern as well.

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I know I'm just playing into a big stereotype by saying this, but the 00z GFS is a massive outlier in the LR. :)

It has decent ensemble agreement, though most are slower with the transition into NPAC troughing.

 

Here's the d11-15 GEFS, during the transition..

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/F5364515-ADF6-43C2-8324-F04B1DE8A2DA_zpstukmm3kr.gif

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FWIW, the 00z ECMWF is also going with the slower transition overall, would be towards the second week of October. The GGEM ensembles are also slower with the transition versus the OP GFS.

 

So, I think it's safe to say the 00z GFS is a fast outlier (for now at least). Though it appears to be handling the shortwave/ULL over the Great Lakes better than the ECMWF..

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The 6z GFS certainly keeps things cool longer than the 0z.  On another note it looks like a major threat coming for a Gulf Coast hurricane.  Amazing to see such consistency on something like that so far out.

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Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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I think if anything, the opposite has been true in recent years. Note that the higher-performing -ENSO winters this century (2008/09, 2010/11, and 2013/14) were fairly ridgy in October, while the crappier -ENSO winters (2005/06, 2007/08, 2011/12) were generally troughier and/or zonal.

 

Also, the Octobers preceding 1978/79 and 1988/89 were generally warm/ridgy. So, I don't think there's a huge correlation here.

 

October 2008 was actually rather chilly here.  The cold October correlation is pretty remarkable though not perfect.  1949, 1955, 1956, 1970, 1971, 1983, and 1984.  An NPAC GOA trough in October wouldn't be the end of our chances but it might lessen our chances of a truly great winter (which I think is on the table right now).

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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October 2008 was actually rather chilly here. The cold October correlation is pretty remarkable though not perfect. 1949, 1955, 1956, 1970, 1971, 1983, and 1984. An NPAC GOA trough in October wouldn't be the end of our chances but it might lessen our chances of a truly great winter (which I think is on the table right now).

Yeah, but notice how "old" those years are. Given the changes in the Hadley/Walker ratios and waveguide climatology over the last 30+ years, I'm not sure the relationships today are anything like what they were then.

 

In the satellite era, here's all -ENSO Octobers that preceded solid winters in the PNW lowlands (1978/79, 1983/84, 1984/85, 1988/89, 1995/96, 2008/09, 2010/11, 2013/14):

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-09/F1609145-24AF-44B1-822A-86141A4CBF44_zpsv83a32ln.png

 

Now, here's all -ENSO Octobers that preceded crappier winters in the PNW lowlands (1980/81, 1985/86, 1996/97, 1998/99, 1999/00, 2000/01, 2005/06, 2007/08, 2011/12):

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-09/00C06AEC-756B-4FF6-9D20-DDB333F68DA3_zpsqiqzhd4t.png

 

If anything, it looks like the ridgier Octobers are a better correlator to good winters in the PNW nowadays. The one similarly with regards to older winters is that stronger ridging over Alaska in October still correlates to better winters in the PNW.

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Yeah, but notice how "old" those years are. Given the changes in the Hadley/Walker ratios and waveguide climatology over the last 30+ years, I'm not sure the relationships today are anything like what they were then.

 

In the satellite era, here's all -ENSO Octobers that preceded solid winters in the PNW lowlands:

 

 

Now, here's all -ENSO Octobers that preceded crappier winters in the PNW lowlands:

 

 

If anything, it looks like the ridgier Octobers are a better correlator to good winters in the PNW nowadays.

 

You definitely can't use 1985 as a crappy winter.  That season featured the coldest November  / December combo in the 20th century by far.  The November alone was better than anything since.

 

You make a good case, but none of the winters in the modern era were truly great by pre 1975 standards.  I think the abnormal GOA ridging this summer was a sign things might have changed since no recent cold ENSO summers even come close to matching it.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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You definitely can't use 1985. That season featured the coldest November / December combo in the 20th century by far. The November alone was better than anything since.

I didn't know you were including November, my bad. However, even if I switch 1985/86, I get the same average result:

 

"Good winter" -ENSO Octobers:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-09/33BE09CA-5901-4591-999D-9AA1221A1DF3_zps4kljroqc.png

 

"Crappier winter" -ENSO Octobers:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-09/9886F921-1F8C-4B21-A24B-1969A6A271AD_zps22ikvbha.png

 

Notice how the signal over Eurasia flips as well.

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The "western Siberia" correlation is actually quite strong in the raw aggregate, stronger than anything over the US. A coherent western-Siberian ridge seems to be generally bad news for winter, while a coherent western-Siberian vortex seems to be generally good news for winter.

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I didn't know you were including November, my bad. However, even if I switch 1985/86, I get the same average result:

 

"Good winter" -ENSO Octobers:

 

 

"Crappier winter" -ENSO Octobers:

 

 

Notice how the signal over Eurasia flips as well.

 

Normally I don't include November, but that one was truly historic.

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Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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The "western Siberia" correlation is actually quite strong in the raw aggregate, stronger than anything over the US. A coherent western-Siberian ridge seems to be generally bad news for winter, while a coherent western-Siberian vortex seems to be generally good news for winter.

 

It actually appears the opposite sine in Eastern Siberia also works.  Might be interesting to look at that for the pre 1975 years.

  • Like 1

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Normally I don't include November, but that one was truly historic.

I gotcha. Personally I wouldn't enjoy a winter that blew it's load in November, but that's just me.

 

I guess what I'm saying is, correlations change over time, as the systematic boundary state(s) change over time. It could very well be that the correlation between October and -ENSO winters in the PNW has reversed, changed, or degraded over the last 30+ years. If October winds up warmer than average or ridgy in the upper levels, I honestly wouldn't sweat it..might be a good sign!

 

It certainly was a good sign in 1978/79, 1988/89, 2008/09, 2010/11, and 2013/14. :)

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It actually appears the opposite sine in Eastern Siberia also works. Might be interesting to look at that for the pre 1975 years.

Definitely. Will look into that today.

 

I love messing around with analogs, haha.

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Have to say, I'm a huge fan of the Alaskan blocking progged by the modeling to open October. That's another general correlation that still holds today..Alaskan blocking during the Autumn generally correlates to stronger NPAC blocking during D/J/F.

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Looks like the 12z GFS will come into better agreement with its ensemble mean and the 00z EPS mean, with the slower transition into the NPAC trough response, during the 2nd week of October instead of the 1st week. Monster polar block on this run, also.

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Some interesting charts from Anthony Masiello on Twitter.

 

First is a modest general correlation between the geomagnetic AP index and the D/J/F NAO index. Looks like general, unsmoothed R value of ~+0.3.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-09/D2A2531D-80A3-47E2-B44C-02A4AE19362B_zps4hcfzd8n.jpg

 

Second chart takes note of the incredible -NAO stretch in recent summers. Major changes to the warm season Atlantic Hadley Cell and Bermuda High since 2006.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-09/9E236119-1DDC-41C2-98DA-06484B49AB48_zpsvzr9b6p5.jpg

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Yeah, but notice how "old" those years are. Given the changes in the Hadley/Walker ratios and waveguide climatology over the last 30+ years, I'm not sure the relationships today are anything like what they were then.

 

In the satellite era, here's all -ENSO Octobers that preceded solid winters in the PNW lowlands (1978/79, 1983/84, 1984/85, 1988/89, 1995/96, 2008/09, 2010/11, 2013/14):

 

Now, here's all -ENSO Octobers that preceded crappier winters in the PNW lowlands (1980/81, 1985/86, 1996/97, 1998/99, 1999/00, 2000/01, 2005/06, 2007/08, 2011/12):

 

If anything, it looks like the ridgier Octobers are a better correlator to good winters in the PNW nowadays. The one similarly with regards to older winters is that stronger ridging over Alaska in October still correlates to better winters in the PNW.

The thing is, over half of the "ridgier" Octobers you pointed out (1978, 1983, 1984, 1995, 2008 and 2013) were below to even well below average in the western lowlands.
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I gotcha. Personally I wouldn't enjoy a winter that blew it's load in November, but that's just me.

 

I guess what I'm saying is, correlations change over time, as the systematic boundary state(s) change over time. It could very well be that the correlation between October and -ENSO winters in the PNW has reversed, changed, or degraded over the last 30+ years. If October winds up warmer than average or ridgy in the upper levels, I honestly wouldn't sweat it..might be a good sign!

 

It certainly was a good sign in 1978/79, 1988/89, 2008/09, 2010/11, and 2013/14. :)

Well don't consider buying property and moving to the PNW then.  Late November thru mid- December is our peak.

 

Not sure if 2013-14 deserves to be in the "good winter" category.  Feels like it would have averaged out near normal across the region.  Obviously people in Oregon were happy but I seem to remember some anger with those in the Puget sound 

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The thing is, over half of the "ridgier" Octobers you pointed out (1978, 1983, 1984, 1995, 2008 and 2013) were below to even well below average in the western lowlands.

Yeah, surface temperatures often don't reflect the upper level pattern(s). That's why I chose 500mb height anomalies.

 

When I tried to correlate using surface and/or 925mb temperatures, I got a steaming pile of crap, as far as correlations are concerned.

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Yeah, but notice how "old" those years are. Given the changes in the Hadley/Walker ratios and waveguide climatology over the last 30+ years, I'm not sure the relationships today are anything like what they were then.

 

In the satellite era, here's all -ENSO Octobers that preceded solid winters in the PNW lowlands (1978/79, 1983/84, 1984/85, 1988/89, 1995/96, 2008/09, 2010/11, 2013/14):

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-09/F1609145-24AF-44B1-822A-86141A4CBF44_zpsv83a32ln.png

 

Now, here's all -ENSO Octobers that preceded crappier winters in the PNW lowlands (1980/81, 1985/86, 1996/97, 1998/99, 1999/00, 2000/01, 2005/06, 2007/08, 2011/12):

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-09/00C06AEC-756B-4FF6-9D20-DDB333F68DA3_zpsqiqzhd4t.png

 

If anything, it looks like the ridgier Octobers are a better correlator to good winters in the PNW nowadays. The one similarly with regards to older winters is that stronger ridging over Alaska in October still correlates to better winters in the PNW.

 

The way you divide the years is pretty subjective. SW already pointed out 1985-86 was actually a very good winter (a February event in addition to the historic November). Why was 1983-84 a "good" winter but 1998-99 wasn't? Both had major Arctic blasts in December but little snow. And 1996-97 had massive snowfall for much of the Puget Sound region and lower BC in December. 2011-12 was not a "bad" winter either, at least for western WA it was much better than 2013-14 for snowfall.

 

I will say that your first list featured blockier winters overall.

A forum for the end of the world.

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The way you divide the years is pretty subjective. SW already pointed out 1985-86 was actually a very good winter (a February event in addition to the historic November). Why was 1983-84 a "good" winter but 1998-99 wasn't? Both had major Arctic blasts in December but little snow. And 1996-97 had massive snowfall for much of the Puget Sound region in December. 2011-12 was not a "bad" winter either, at least for western WA it was much better than 2013-14 for snowfall.

 

I will say that your second list featured blockier winters overall.

are you sure?

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Well don't consider buying property and moving to the PNW then.  Late November thru mid- December is our peak.

 

Not sure if 2013-14 deserves to be in the "good winter" category.  Feels like it would have averaged out near normal across the region.  Obviously people in Oregon were happy but I seem to remember some anger with those in the Puget sound 

 

Historically our peak is in January.  There has been much discussion on here about that.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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The thing is, over half of the "ridgier" Octobers you pointed out (1978, 1983, 1984, 1995, 2008 and 2013) were below to even well below average in the western lowlands.

 

Actually 1984 was a very cold October.  The entire final 2/3 of the month was cold.

  • Like 1

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Share on other sites

12z GFS is much more to my liking.  At one point gradients go flat with thicknesses in the 530s.  That will undoubtedly be chilly if it verifies.  SEA in particular does much better when onshore flow is deadened.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Well don't consider buying property and moving to the PNW then. Late November thru mid- December is our peak.

Haha. Do I sense a hint of sarcasm?

 

Isn't that more of a recent tendency? Seems to be a big debate here on it, that's for sure. Do the last ~30 years represent some sort of fluke, or is this a true shift associated with the observed changes in the semipermanent climatological circulations across the globe since the late 1970s?

 

Not sure if 2013-14 deserves to be in the "good winter" category. Feels like it would have averaged out near normal across the region. Obviously people in Oregon were happy but I seem to remember some anger with those in the Puget sound

I admit my analysis is somewhat limited, better for large scale upper level comparisons. I've been told that some "zonal" years are just cold enough to perform in northern zones, while screwing southern zones, and I've been told that some blocky years tend to favor southern areas and shaft northern zones. Stuff like this is well beyond my pay grade. :)

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Historically our peak is in January.  There has been much discussion on here about that.

I know and I have read most of it.  No reason to think that it will suddenly snap back.  It might but it might not.  The 1981-2010 averages for Shawnigan Lake show December averages more than 0.5F colder.  And nothing has changed in the last 6 years.  36 years seems too long to just be written off as fluke. 

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I know and I have read most of it.  No reason to think that it will suddenly snap back.  It might but it might not.  The 1981-2010 averages for Shawnigan Lake show December averages more than 0.5F colder.  And nothing has changed in the last 6 years.  36 years seems too long to just be written off as fluke. 

 

We do have a couple of factors that could put us back on track.

 

1. Record high positive height and surface pressure anoms over the North Pacific this summer (historically a good sign)

2. Extreme solar minimum (probably a grand minimum coming up)

3. Coming off of a super El Nino...probably the most extreme warm ENSO event since the early 1940s.  This could have given the atmosphere a proverbial kick in the arse.

 

I think there is a reasonable chance would could see the peak of our winter average out around mid January over the next 5 years or so. One fact that absolutely blows my mind is Seattle actually averaged colder in February than December during the 1890 to 1940 period, not to mention January!

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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The 12z ensemble really pulled back on the idea of warming at the beginning of the second week of October.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Share on other sites

The 12z ensemble really pulled back on the idea of warming at the beginning of the second week of October.

 

 

Good to know that the ensembles show something different in 17 days.

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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The way you divide the years is pretty subjective. SW already pointed out 1985-86 was actually a very good winter (a February event in addition to the historic November). Why was 1983-84 a "good" winter but 1998-99 wasn't? Both had major Arctic blasts in December but little snow. And 1996-97 had massive snowfall for much of the Puget Sound region and lower BC in December. 2011-12 was not a "bad" winter either, at least for western WA it was much better than 2013-14 for snowfall.

 

I will say that your second list featured blockier winters overall.

I'm merely analyzing D/J/F, and looking at which years featured consistent upstream blocking and cold, continental influence on a (somewhat) consistent basis.

 

Years like 1998/99 and 2011/12 were fairly crappy/zonal overall, minus a few brief excursions. There's no way to scientifically analog for fluky, intraseasonal behaviors like that. I'm just analyzing the overall pattern, and noting which years were generally the coldest from the surface to 800mb.

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The 12z GEFS does depict a strong NPAC trough, however it establishes far enough west to constructively feed-back with the NEPAC/EPO block.

 

This is a very nice look. No signs of a raging Alaskan vortex or zonal flow of any kind, while that vortex SW of the Aleutians promotes enhanced poleward wave driving, hence the strong anticyclone over the EPO domain, and a weaker upper level polar vortex (at least versus +QBO climo).

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/7596D197-99FC-4450-96A1-48982B6F9565_zpsdnfg23do.gif

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I'm merely analyzing D/J/F, and looking at which years featured consistent upstream blocking and cold, continental influence on a (somewhat) consistent basis.

 

Years like 1998/99 and 2011/12 were fairly crappy/zonal overall, minus a few brief excursions. There's no way to scientifically analog for fluky, intraseasonal behaviors like that. I'm just analyzing the overall pattern, and noting which years were generally the coldest from the surface to 800mb.

 

Ok, I was just going by what your post said: "solid winters for the PNW". :)

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Just to elaborate, here's how the "blocky" winters looked over the lower-48:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/DF9ECE32-FD4B-46E2-846B-D9DCC8476BB4_zps6kwcawqa.png

 

Here's how the "zonal" winters looked over the lower-48:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/CB9067F0-9052-4B0B-92A7-64DF18392F3C_zpsp2lub31j.png

 

Wanna guess which group featured troughier Octobers in the PNW? ;)

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Just to elaborate, here's how the "blocky" winters looked over the lower-48:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/DF9ECE32-FD4B-46E2-846B-D9DCC8476BB4_zps6kwcawqa.png

 

Here's how the "zonal" winters looked over the lower-48:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/CB9067F0-9052-4B0B-92A7-64DF18392F3C_zpsp2lub31j.png

 

Wanna guess which group featured troughier Octobers in the PNW? ;)

 

Yes, but you have to remember that the PNW is kind of a different animal. Some of their best winters have come during winters that weren't great for most the nation.

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Yes. They had more amplified and sustained blocking overall. Not necessarily it the right place at all times.

My second list? I assume you meant my first list, correct?

 

The years in my second list weren't blocky at all.

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My second list? I assume you meant my first list, correct?

 

The years in my second list weren't blocky at all.

 

Whoops, yes the first list.

 

However, again I think you have to remember that the PNW can do very well with winters that don't fit your definition of blocky. And 1983-84, blockier though it may have been, was really no better for the PNW than 1998-99. As just one example.

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