La Niña/Winter 2016-17 Discussion

[40/70 Benchmark]

2 hours ago, packbacker said:

Yep...high odds for +NAO winters.  But, we should be used to that by now and there have been plenty of cold/snowy winters with +NAO's.  Though, personally I don't think a cold/snowy +NAO winter is high probably either...something along Grits outlook is what I am expecting.

I think Grtis outlook appeared very reasonable.

[Stebo]

2 hours ago, Dsnowx53 said:

Griteater's post was great. His ideas made a lot of sense.

I will say this, though. I think too many people are lumping in moderate and strong Ninas into their analysis for what goes on with a +QBO or when the Nina is central-based. The intensity matters a lot, too. When you had a WEAK Nina with it located in the CP, the DJFM NAO averaged +0.0328, which is essentially neutral. So I don't necessarily agree that the CP Weak Nina is a +NAO indicator. I used griteater's chart and took the average of just the weak Ninas from this chart, since this winter looks to be a weak Nina.

 

A lot of the weak Ninas also had a low December NAO, and when combined with things going on in the stratosphere, I agree with December being a -AO, -NAO month with cold in the E US. There is evidence of a higher NAO as the winter goes on, though. 

I would agree of the 3 winter months, December would be the one I'd peg at potentially being -NAO. The magnitude and location would dictate the blocking at that point.

[Stebo]

1 minute ago, 40/70 Benchmark said:

I think Grtis outlook appeared very reasonable.

Yeah plus the further north you go the less the NAO can be a deal breaker, +NAO up in New England isn't killer if the AO is favorable negative.

[40/70 Benchmark]

4 minutes ago, Stebo said:

Yeah plus the further north you go the less the NAO can be a deal breaker, +NAO up in New England isn't killer if the AO is favorable negative.

I think the AO will cooperate, but he NAO and Pacific likely average out relatively meek.,,,everything biased more favorably early on.

I like December and the second half of Feb or 1st half of March for more sustained NAP assist.

 

[Stebo]

Just now, 40/70 Benchmark said:

I think the AO will cooperate, but he NAO and Pacific likely average out relatively meek.

 

Yeah the EPO would be needed for the cold source, my worry right now is all the cold is on the other side of the world. Canada is a blowtorch right now outside of near Greenland.

[40/70 Benchmark]

1 minute ago, Stebo said:

Yeah the EPO would be needed for the cold source, my worry right now is all the cold is on the other side of the world. Canada is a blowtorch right now outside of near Greenland.

I think that changes by xmas, but folks have rushed it.

I could see a Dec 2002 type month....where interior cleans up, but coast has issues.

[Stebo]

3 minutes ago, 40/70 Benchmark said:

I think that changes by xmas, but folks have rushed it.

I could see a Dec 2002 type month....where interior cleans up, but coast has issues.

02-03 was one of the years I thought this winter would follow, the eastern lakes do well but Chicago and north get left behind a bit.

[40/70 Benchmark]

I envision a great deal of inland runners that redevelop.

[PB GFI]

28 minutes ago, Stebo said:

02-03 was one of the years I thought this winter would follow, the eastern lakes do well but Chicago and north get left behind a bit.

 

I did rush this at 2 M and failed with a good old theory that the first start is usually false start .

I originally thought this would start around the 10th and at 500 it may , but the ridge doesn't totally retrograde yet .

So it fails .

Then I fell back to the 15th and even there with a decent 500 , it's all Polar Pacific air traveling over bare ground. 

 

Now the guidance is onto the 15th thru 25th , which I am cautious of because of its inability to see any cross polar flow in the pattern .

To make matters worse both the weeklies and JMA kick up a SE ridge week 4 and develop the trough in the lakes. 

I know you like 02 03 I like 83 84.Where December went crazy and then it just backed off. 

I am all in on December,  I just thought this would come out of the box better ,  it's going to be slow. 

 

[Stebo]

3 minutes ago, PB GFI said:

 

I did rush this at 2 M and failed with a good old theory that the first start is usually false start .

I originally thought this would start around the 10th and at 500 it may , but the ridge doesn't totally retrograde yet .

So it fails .

Then I fell back to the 15th and even there with a decent 500 , it's all Polar Pacific air traveling over bare ground. 

 

Now the guidance is onto the 15th thru 25th , which I am cautious of because of its inability to see any cross polar flow in the pattern .

To make matters worse both the weeklies and JMA kick up a SE ridge week 4 and develop the trough in the lakes. 

I know you like 02 03 I like 83 84.Where December went crazy and then it just backed off. 

I am all in on December,  I just thought this would come out of the box better ,  it's going to be slow. 

 

Yeah with all the cold bottled up in Russia there is a need to be concerned, it is still very early though.

[packbacker]

2 hours ago, PB GFI said:

 

I did rush this at 2 M and failed with a good old theory that the first start is usually false start .

I originally thought this would start around the 10th and at 500 it may , but the ridge doesn't totally retrograde yet .

So it fails .

Then I fell back to the 15th and even there with a decent 500 , it's all Polar Pacific air traveling over bare ground. 

 

Now the guidance is onto the 15th thru 25th , which I am cautious of because of its inability to see any cross polar flow in the pattern .

To make matters worse both the weeklies and JMA kick up a SE ridge week 4 and develop the trough in the lakes. 

I know you like 02 03 I like 83 84.Where December went crazy and then it just backed off. 

I am all in on December,  I just thought this would come out of the box better ,  it's going to be slow. 

 

Not a lot of weak -enso analogs that are warm for Nov...4 of 19 from a quick check.  Only one had warm conus for both Oct/Nov...2005.  It did flip in Dec though.  Jan wasn't pretty though.  Although I am sure you and Stebo's locales did fine. 

Edit:  had to post Jan 05 temps. Would be funny if we got this as a repeat. 

 

[Stebo]

54 minutes ago, packbacker said:

Not a lot of weak -enso analogs that are warm for Nov...4 of 19 from a quick check.  Only one had warm conus for both Oct/Nov...2005.  It did flip in Dec though.  Jan wasn't pretty though.  Although I am sure you and Stebo's locales did fine. 

Edit:  had to post Jan 05 temps. Would be funny if we got this as a repeat. 

 

December of 2005 we ended up with 19.4" here in Detroit but the rest of the winter was horrible. Ended up with 36.3" November of 05 had 4.3 so most of that winter was done by January 1st.

[Isotherm]

Latest 30hpa QBO value is +12.83, an increase [more positive] versus last month. Unprecedented occurrence w/ such a protracted +QBO cycle, given the typical periodicity of < 15 months per phase.

[uncle W]

the QBO is above +10 for the second straight October...That's never happened before...Oct. QBO before our snowiest winters...

1955.....+9.02

1957...+10.46

1959...+11.69

1960....-15.62

1963.....+7.54

1966...+11.00

1968....-14.58

1977......-1.81

1993......-4.04

1995.....+3.43

2000....-14.04

2002.....+7.66

2003....-20.34

2004.....+8.00

2005....-28.76

2009....-11.69

2010...+10.83

2013...+11.69

2014....-23.86

2015...+13.38

2016...+12.83

[uncle W]

57 minutes ago, bluewave said:

Another first this October was the greatest SOI drop on record from September to October starting above +10 in September since 1876.

It's also the first time since 1984 that a La Nina had an October -4 or lower SOI.

ftp://ftp.bom.gov.au/anon/home/ncc/www/sco/soi/soiplaintext.html

1995 had a negative soi in October and again in December...1966 and 1980 had a negative soi the last four months of the year...neutral negative years after el nino...66 keeps popping up on the analog lists...+QBO and -SOI...

[psuhoffman]

20 hours ago, snowman19 said:

Pointing out the obvious with the North Atlantic is not a cherry pick. There is no semblance whatsoever of a tripole configuration, in fact the North Atlantic sstas are going into the freezer. I'm sorry if that doesn't support west-based Greenland blocked -NAO but it is what it is. There are other factors against it, modoki La Niña, +QBO, which I already pointed out with links to the research supporting that recently in this thread

It's cherry picking because you only talk about factors that favor warm. You ignore things like the October SAI or some of the snowcover correlations or the analog based models that show cold or the guidance that shows the PDO recovering. You also use the QBO like its always a determining factor when it's correlation to snow hasn't been shown to be all that strong. Now I'm not using any of that to discount your observations just playing devils advocate and showing how you have a source selection bias. You talk about the pdo like it's definitely going to be negative when that isn't a forgone conclusion yet. You also become invisible when it's looking good for snow. Why were you in the mid atl forum constantly when it was torching but when things looked better in mid January suddenly you went on hiatus?  it's ok to decide you think the indicators leaning warm are more important but when all you do is beat the drum on one side and never discuss factors that might disagree with your narrative it's pretty transparent. Like I said you are like JBs evil twin or something. 

[snowman19]

40 minutes ago, bluewave said:

Also pretty weak trades in October for a developing La Nina a little lighter than 1995.

Nino 3.4 for October was slightly warmer than October 1995 was.

1995  10   25.96   26.88   -0.92

2016  10   26.06   26.91   -0.84

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/detrend.nino34.ascii.txt

 

 

 

 

 

 

Despite the SOI disconnect, region 3.4 sstas have stayed solidly in weak La Niña mode 

[snowman19]

32 minutes ago, psuhoffman said:

It's cherry picking because you only talk about factors that favor warm. You ignore things like the October SAI or some of the snowcover correlations or the analog based models that show cold or the guidance that shows the PDO recovering. You also use the QBO like its always a determining factor when it's correlation to snow hasn't been shown to be all that strong. Now I'm not using any of that to discount your observations just playing devils advocate and showing how you have a source selection bias. You talk about the pdo like it's definitely going to be negative when that isn't a forgone conclusion yet. You also become invisible when it's looking good for snow. Why were you in the mid atl forum constantly when it was torching but when things looked better in mid January suddenly you went on hiatus?  it's ok to decide you think the indicators leaning warm are more important but when all you do is beat the drum on one side and never discuss factors that might disagree with your narrative it's pretty transparent. Like I said you are like JBs evil twin or something. 

We have had several SAI big fails over the last several years, it is far from very dependable indicator. Not saying it's valueless but we need to learn a lot more about it, and that's years away. The PDO is doing anything but recovering to positive. Look at the latest 7 day change: 

[packbacker]

9 minutes ago, snowman19 said:

We have had several SAI big fails over the last several years, it is far from very dependable indicator. Not saying it's valueless but we need to learn a lot more about it, and that's years away. The PDO is doing anything but recovering to positive. Look at the latest 7 day change: 

I think we have beaten this NAO/PDO to death.  We all agree...weakening PDO and background favors +NAO.  I don't know anyone going wall to wall cold/snowy, not even JB :-). Seasonal weak Nina looks probable with Dec being best chance of BN.  

Top 5 strongest SCE years have been rather harsh winters...does this one buck that trend.

[snowman19]

3 hours ago, Isotherm said:

Latest 30hpa QBO value is +12.83, an increase [more positive] versus last month. Unprecedented occurrence w/ such a protracted +QBO cycle, given the typical periodicity of < 15 months per phase.

I can't believe this westerly QBO event is still gaining strength. The way it is forecasted will have to change after this year

[Stebo]

2 hours ago, bluewave said:

The 500 mb atmospheric response since October has been more indicative of a +PDO with the record Alaska blocking tie for October and very active Aleutian Low. Though the variation in the typical +PDO location of the Aleutian Low and strong PAC JET are probably the weak La Nina exerting some influence.

 

 

I would argue it has shown the exact opposite especially when you look up and down stream of where the ridge should be. you have a ridge nw of Hawaii, that isn't in typical +PDO Octobers, you also have a ridge across most of middle part of the US where you usually have a trough. You also have a massive trough along the west coast which is normally ridging. If anything with the ridge in Alaska retrograded more northwest, I would consider this to show a -PDO atmospheric response, which would make sense since the PDO has steadily gone down through October.

[Stebo]

2 minutes ago, bluewave said:

This is mostly the opposite of the October La Nina -PDO and La Nina response at 500 mb which is a deep trough over Alaska instead of a ridge.

But you can see the La Nina influence with the weaker ridge NW of Hawaii and the active Pac Jet undercutting the +PDO Alaskan Ridge.

So the end result is a combination +PDO La Nina pattern. The coming retrogression of the Aleutian Low back to the west and the amplification

of the ridge over western north America the next few weeks is textbook +PDO for November. This will be the first La Nina since 1984-85

that the +PDO increased from September to October slightly instead of weakening.

 

 

 

I am just not seeing it and the PDO value has gone down not up in October...

[Stebo]

21 minutes ago, bluewave said:

The waters right along the West Coast warmed in October from September so the official update for October which isn't out yet may show an increase.

Remember that you can still get a significant +PDO contribution to the pattern whether the number is a lower positive or a higher one.

 

http://research.jisao.washington.edu/pdo/PDO.latest.txt

Through September

 

2016**   1.53   1.75   2.40   2.62   2.35   2.03   1.25   0.52   0.45

The problem with looking at this is you are looking at just the coast, the PDO covers a large area. Also the monthly average has most of the PDO going down, just the area near California was becoming more of a +PDO representation. 

[Stebo]

8 minutes ago, bluewave said:

The official monthly average hasn't updated yet for October. It may only be a slight gain over September. But there is still an abundant area of warm waters within

the PDO region off the western portion of NOAM and CA. So a few points here or there in the index won't make that much of a difference in the sensible weather.

We will see but I would bet on the PDO dropping for October.

[Isotherm]

12 minutes ago, bluewave said:

It doesn't really matter whether it rises or falls a bit since it's still positive and matches a 500 MB LA Nina/+PDO response.

The retrogression of the ridge the next few weeks back to the West Coast of North America is a text book NOV +PDO pattern.

But the influence of the Nina driven PAC Jet combined with other teleconnectors will result in record warmth continuing

for a while longer in North America.

 

The z500 pattern will project onto the climatological Nov/+PDO configuration for a transient period during the retrogression. By the latter part of November, the ECMWF ensembles depict the Aleutian/Alaskan mid level ridge w/ a concomitant low height field developing downstream over the Western US, reflective of the decreasing atmospheric angular momentum and resultant retracted jet. I think we'll be transitioning into a more classic Nina forcing / low AAM / -PDO configuration by the third week of November. Whether we maintain that appearance or not remains to be seen, but the second half of November should be much different than the first half insofar as the Pacific pattern.

 

 

[Isotherm]

30 minutes ago, Stebo said:

We will see but I would bet on the PDO dropping for October.

 

 

Would tend to agree. It will likely still be positive, but the current SSTA against the global mean is probably only slightly positive.

 

[Stebo]

24 minutes ago, bluewave said:

It doesn't really matter whether it rises or falls a bit since it's still positive and matches a 500 MB LA Nina/+PDO response.

The retrogression of the ridge the next few weeks back to the West Coast of North America is a text book NOV +PDO pattern.

But the influence of the Nina driven PAC Jet combined with other teleconnectors will result in record warmth continuing

for a while longer in North America.

Even if it is +PDO how positive will it be, 0.10-0.20? That is so marginal that it won't have much influence and furthermore it would still be falling.

[snowman19]

1 hour ago, Stebo said:

Even if it is +PDO how positive will it be, 0.10-0.20? That is so marginal that it won't have much influence and furthermore it would still be falling.

I couldn't agree more. Bottom line is we have totally lost the dominating, stout +PDO that we've seen since 2014. Like Isotherm said, do we really believe that there will be a huge difference between a PDO index number of +0.30 or -0.30? We are arguing semantics at this point. The PDO has clearly dropped, has been steadily dropping for months and the upcoming pattern only argues for a further drop

[Isotherm]

1 hour ago, bluewave said:

 

It's tough to predict what things will look like past the next week to 10 days beyond the point of the regression. But ridging staying put near Alaska 

later on in November into December would be indicative  of a continuing +PDO influence on this weak La Nina pattern.

 

This October featured a record tie for 500 mb blocking over Alaska. The analog composite for strong Alaskan blocking Octobers featured varying

degrees of ridging continuing there through the winter rather than the typical Alaska lower heights with the usual -PDO/ La Nina.

 

The ridging near Alaska and +PDO may also be sustained through possible enhanced rossby wave train activity induced by the near to

record warm SST's and convection in the WPAC.

 

 

 

 

 

 

 

 

 

 

 

The difficulty is isolating the variable of the PDO index as the principal determinant of the z500 pattern, particularly in light of the fact that the sample size for +PDO/Nina's is extremely small.

When we examine +PDO/Weak Nina years such as 1995-96, and 1996-97, their z500 patterns featured a much more retracted jet w/ the mid level ridging centered closer to the longitude of the Aleutians. Conversely, the +PDO/Nina's of 1983-84 and 1984-85 featured the mid level ridging at a longitude further east (centered south of Alaska). I believe the PDO was likely influential in impacting the orientation; however, the disparities in tropical forcing location/magnitude were also significant for 1983-85 vs 1995-97. The latent heat release, associated jet dynamics and concomitant rossby wave train propagation / wave activity flux likely played a role.

 

1983-85 +PDO/Nina:

 

1995-97 +PDO/Nina:

 

 

 

[heavy_wx]

5 minutes ago, Isotherm said:

The difficultly is isolating the variable of the PDO index as the principal determinant of the z500 pattern, particularly in light of the fact that the sample size for +PDO/Nina's is extremely small.

When we examine +PDO/Weak Nina years such as 1995-96, and 1996-97, their z500 patterns featured a much more retracted jet w/ the mid level ridging centered closer to the longitude of the Aleutians. Conversely, the +PDO/Nina's of 1983-84 and 1984-85 featured the mid level ridging at a longitude further east (centered south of Alaska). I believe the PDO was likely influential in impacting the orientation; however, the disparities in tropical forcing location/magnitude were also significant for 1983-85 vs 1995-97. The latent heat release and associated jet dynamics / concomitant rossby wave train propagation and wave activity flux likely played a role.

There is a causality issue with this; I think that coherent tropical convection tends to have a larger influence on the mid-latitude longwave pattern. A ridge forced in the Gulf of Alaska by coherent tropical convection would favor warmer SSTs near the Alaskan coast and a +PDO, instead of the +PDO itself causing the ridging.