Winter 2017-18 Disco

[showmethesnow]

1 hour ago, mitchnick said:

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_sup814.gif

Thanks Mitch. I did have to back track though to get to the home page that generates the analog. For those interested the link is below. Click on the analog link just above the US map.

http://www.cpc.ncep.noaa.gov/products/predictions/814day/

[BristowWx]

4 hours ago, showmethesnow said:

Considering that we are talking a Nina I am actually getting somewhat stoked for this winter. Things I have been seeing over the last month or so would suggest the possibility of wall to wall winter cold with an early start and a late finish. Now whether we can score with snow is another story altogether but give me the cold and the blocking and I would like our chances.

yes...multiple 1-2 inches events would be excellent...way better than getting the big one and watching it melt

[ORH_wxman]

2 hours ago, showmethesnow said:

Thanks Mitch. I did have to back track though to get to the home page that generates the analog. For those interested the link is below. Click on the analog link just above the US map.

http://www.cpc.ncep.noaa.gov/products/predictions/814day/

This is day 8 (days 6-10)

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/model_guidance.php

 

You can choose either the specific OP GFS run itself (not very useful for accuracy, but for entertainment it is) or the ensemble mean. It also has the Canadian ensembles too.

[mitchnick]

45 minutes ago, ORH_wxman said:

This is day 8 (days 6-10)

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/model_guidance.php

 

You can choose either the specific OP GFS run itself (not very useful for accuracy, but for entertainment it is) or the ensemble mean. It also has the Canadian ensembles too.

Thanks!

[SnowLover22]

This is way out there but def not a bad look.

It will be interesting to see what the ensembles show.

 

[showmethesnow]

1 hour ago, ORH_wxman said:

This is day 8 (days 6-10)

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/model_guidance.php

 

You can choose either the specific OP GFS run itself (not very useful for accuracy, but for entertainment it is) or the ensemble mean. It also has the Canadian ensembles too.

Here's another good site for short and extended analogs. Like that it gives you probabilities and means on snow, temps, etc...

 http://www.eas.slu.edu/CIPS/ANALOG/analog.php

[CAPE]

16 minutes ago, Philadelphia Snow said:

This is way out there but def not a bad look.

It will be interesting to see what the ensembles show.

 

Verbatim that period would offer the first legit chance at freezing temps NW of the cities.

[Bob Chill]

It may look nice seeing a -nao on the panels but it's meaningless as a long lead signal in Oct. We had this same conversation in 2012,13, & 14. All three of those Octobers had a fairly persistent -NAO. Late Nov-early Dec is a different story. 

I really like CPC analogs for specific windows and potential events in the 2 week range. It has proven to be a pretty valuable tool in the winter. However, I don't think there is much value in rolling the analogs forward for months. Don't get me wrong though. I love the composites Mitch posted but we still a ways away from getting a bead on potential blocking (or lack there of). 

[ORH_wxman]

21 minutes ago, Bob Chill said:

It may look nice seeing a -nao on the panels but it's meaningless as a long lead signal in Oct. We had this same conversation in 2012,13, & 14. All three of those Octobers had a fairly persistent -NAO. Late Nov-early Dec is a different story. 

I really like CPC analogs for specific windows and potential events in the 2 week range. It has proven to be a pretty valuable tool in the winter. However, I don't think there is much value in rolling the analogs forward for months. Don't get me wrong though. I love the composites Mitch posted but we still a ways away from getting a bead on potential blocking (or lack there of). 

I have also found little value in rolling forward the analogs more than about a week outside of typical climo....by that, I mean in a frothing La Nina pattern in December, we might see a bunch of 2008, 2007, 1970, 1967, 1975 type years come up. So one might say "oh those februarys kind of sucked in the mean"....but that is basically the analogs just telling us that we are in a classic deep -PDO La Nina type pattern, something we don't need the GEFS ensemble mean to tell us anyway. We could have said the same thing just noting an ice bath in the GOA and looking ENSO.

But I agree they've had some pretty good utility in identifying some storm windows within their 2 week range.

[BTRWx]

41 minutes ago, Bob Chill said:

It may look nice seeing a -nao on the panels but it's meaningless as a long lead signal in Oct. We had this same conversation in 2012,13, & 14. All three of those Octobers had a fairly persistent -NAO. Late Nov-early Dec is a different story. 

I really like CPC analogs for specific windows and potential events in the 2 week range. It has proven to be a pretty valuable tool in the winter. However, I don't think there is much value in rolling the analogs forward for months. Don't get me wrong though. I love the composites Mitch posted but we still a ways away from getting a bead on potential blocking (or lack there of). 

Thank you.

[Bob Chill]

22 minutes ago, ORH_wxman said:

I have also found little value in rolling forward the analogs more than about a week outside of typical climo....by that, I mean in a frothing La Nina pattern in December, we might see a bunch of 2008, 2007, 1970, 1967, 1975 type years come up. So one might say "oh those februarys kind of sucked in the mean"....but that is basically the analogs just telling us that we are in a classic deep -PDO La Nina type pattern, something we don't need the GEFS ensemble mean to tell us anyway. We could have said the same thing just noting an ice bath in the GOA and looking ENSO.

But I agree they've had some pretty good utility in identifying some storm windows within their 2 week range.

One of the problems in using analogs in the MA is we don't do snow easy here regardless of any pattern, index, or whatever. We live on the edge practically every single damn storm...and have a knack for having something screw it all up..lol. On this flip side we can get destroyed by epic storms too and they're not terribly infrequent so the little voice saying "hey! there's always a chance!" never shuts the F up. haha

Because our margin for error is so small, analogs can only tell us so much. Two identical enso/pdo/nao/ao etc years will produce very different results.  I constantly have to remind myself of this and I've been doing this long enough to know better. You guys up there can bank on climo much more for snowfall predictions than we can here. Looking at every reliable (and unreliable) indicator right now tells me the odds favor a sub climo snow winter. But pulling an inside straight or 2 can drastically change the #'s. Of course missing the draw a few times (like 10-11) drastically changes things for the worse. We've had a few of those in the 2001-11 decade. 04-05, 06-07, and 10-11 came really close to being memorable or solid winters with snowfall. The sleetfest in Feb 07 was pretty awesome and memorable but 4" of sleet < 12" of snow. 

[showmethesnow]

1 hour ago, Bob Chill said:

It may look nice seeing a -nao on the panels but it's meaningless as a long lead signal in Oct. We had this same conversation in 2012,13, & 14. All three of those Octobers had a fairly persistent -NAO. Late Nov-early Dec is a different story. 

I really like CPC analogs for specific windows and potential events in the 2 week range. It has proven to be a pretty valuable tool in the winter. However, I don't think there is much value in rolling the analogs forward for months. Don't get me wrong though. I love the composites Mitch posted but we still a ways away from getting a bead on potential blocking (or lack there of). 

While I agree that taking a snapshot of one day of analogs really has no value for longer leads I do think there may be some value when you take the analogs as a whole over an extended period of time. When you frequently see the same years popping up day after day, week after week there is a somewhat decent chance that they are seeing a similar pattern as those years featured. And by pattern I mean a little finer detail then just the typical Nina pattern that OR-Wxman had mentioned. That being said I think they have more value when the winter pattern gets established, as opposed to now with the transitional stage we see during fall. Though I wouldn't dismiss them completely out of hand during the fall either. 

[snowman19]

Posted this in the NYC forum, but here is an article written by HM a few years ago on the QBO state during a La Niña. You get totally different results during winter when you have a -QBO/La Niña (this year) versus a +QBO/La Niña: http://ionlyusethegfs.blogspot.com/2012/04/qbo-aleutian-high-relationship.html?m=1

[ORH_wxman]

1 hour ago, Bob Chill said:

One of the problems in using analogs in the MA is we don't do snow easy here regardless of any pattern, index, or whatever. We live on the edge practically every single damn storm...and have a knack for having something screw it all up..lol. On this flip side we can get destroyed by epic storms too and they're not terribly infrequent so the little voice saying "hey! there's always a chance!" never shuts the F up. haha

Because our margin for error is so small, analogs can only tell us so much. Two identical enso/pdo/nao/ao etc years will produce very different results.  I constantly have to remind myself of this and I've been doing this long enough to know better. You guys up there can bank on climo much more for snowfall predictions than we can here. Looking at every reliable (and unreliable) indicator right now tells me the odds favor a sub climo snow winter. But pulling an inside straight or 2 can drastically change the #'s. Of course missing the draw a few times (like 10-11) drastically changes things for the worse. We've had a few of those in the 2001-11 decade. 04-05, 06-07, and 10-11 came really close to being memorable or solid winters with snowfall. The sleetfest in Feb 07 was pretty awesome and memorable but 4" of sleet < 12" of snow. 

Yeah a close miss can be the difference between below average and a decent winter. The Feb 24-25, 2005 system is a good example...that one prob hits DC harder in a lot of cases than it actually did in reality. You'd prob roll the dice on that one again and do better in the means. On the flip side, the Feb 25, 2007 event is not one you'd want to roll the dice on again...that was a fortunate positive bust. But we'd def roll the dice again for 2/14/07...might get a few snowier solutions on that one if a few things were just slightly perturbed.

[mitchnick]

Just in case anyone was wondering, "No", I do NOT put much, if any, stock in that analog map ever. But it is fun to look at the years it spits out when there's nothing else to look at for something to do. The one I posted incredibly included nino, nina, and nada years, but all coincidentally included great/decent winters. But even if it arguably has "some" value as a forecasting tool, it's meaningless at this time of the year unless you care about the weather in late October for the years listed.

[showmethesnow]

Latest ENSO discussion

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

[Bob Chill]

Personally, I'm not convinced that the SAI is a meaningful as it was first sold to us a few years back. I have theory as to why it isn't as reliable but I'll get into that at the end of this post. 

So far the Oct SAI has been showing AN snowcover in Siberia and the month has been progressing in such a way that would support higher odds of a -AO based on Cohen's theory. Looking at the data, the closest match to this day in recent years is 2014. If you guys remember the SAI disco in 2014, we were all banking on a -AO. Oops. 

Current graph:

 

Current Chart:

 

Current Anomaly:

 

The last year that had a larger anomaly in Siberia is 2014:

 

How is it looking over the next 10 days or so? Pretty good in general. Snow extent south of 60N looks like it will advance quite well over the next 10 days. This is just the 12z gfs panel but ens and previous op runs all support a similar outcome:

 

 

 

IIRC, the importance of the anomaly is based on snow cover growth south of 60N. 2014 was way ahead of this year but this year is going well south of 60N and progs look favorable.  So far Oct 2017 is doing well for increased odds of a -AO based on Cohen's theory. Unfortunately, we've been fooled once or twice or thrice recently so does any of this really matter? I think there is some merit (probably more than we think after getting fooled) but I've formed a bit of a theory as to why it seems to not work so well.

2014 was a SLAM DUNK based on the SAI theory but the end result was pretty lame. We did get a -AO in Jan but the winter on the whole was definitely not "blocky" in the AO/NAO domain. The bigger story in 13-14 and 14-15 was the persistent -EPO. Cohen spun this well because the -EPO did produce cold in the areas that support his SAI theory but nobody can ever convince me that this was not a case of "right for the wrong reasons". A quote from Cohen's blog at the beginning of Oct is what got my gears turning about why the SAI/-AO correlation has been off the last few years:

"Arctic sea ice reached its annual minimum on September 13th. Despite that Arctic sea ice is now growing, large swaths of the North Pacific side of the Arctic basin are ice-free (Figure 11). Recent research has shown that regional anomalies are important and the sea ice region most highly correlated with the winter AO is the Barents-Kara seas region where low Arctic sea ice favors a negative winter AO. However it is early and the magnitude of winter sea ice anomalies in the Barents Kara Seas and other seas in the Arctic are not currently known.  Given that sea ice is running below normal, this currently favors more extensive Siberian snow cover in the coming weeks, followed by a strengthened Siberian high and a weakened polar vortex/negative AO this upcoming winter."

 

The thing is, the low ice area in the Barents and Kara Seas is pretty much guaranteed almost EVERY year now. Unless arctic sea ice makes some sort of unprecedented comeback, low ice volume in this region during the Fall will continue indefinitely. If this anomaly is causing increased Siberian snowcover (seems like it might) then we should have a -AO almost every winter (which we aren't). See where I'm coming from? The current sea ice over the last 10 years has gone through rapid and substantial changes but Cohen's research stretches back many years before that. So my theory is that the SAI theory pre-2007 probably works much better than post 2007. Especially post 2012. I'm probably over simplifying this but it makes sense in my head. If the SAI is grounded on Siberian snowcover in Oct over large time scales but there has been significant changes in weather patterns due to reduced sea ice volume that can't recover to 1980-2010 climo then the entire premise is probably permanently flawed. That's my theory and I'm sticking to it. lol

 

[mitchnick]

14 minutes ago, Bob Chill said:

Personally, I'm not convinced that the SAI is a meaningful as it was first sold to us a few years back. I have theory as to why it isn't as reliable but I'll get into that at the end of this post. 

So far the Oct SAI has been showing AN snowcover in Siberia and the month has been progressing in such a way that would support higher odds of a -AO based on Cohen's theory. Looking at the data, the closest match to this day in recent years is 2014. If you guys remember the SAI disco in 2014, we were all banking on a -AO. Oops. 

Current graph:

 

Current Chart:

 

Current Anomaly:

 

The last year that had a larger anomaly in Siberia is 2014:

 

How is it looking over the next 10 days or so? Pretty good in general. Snow extent south of 60N looks like it will advance quite well over the next 10 days. This is just the 12z gfs panel but ens and previous op runs all support a similar outcome:

 

 

 

IIRC, the importance of the anomaly is based on snow cover growth south of 60N. 2014 was way ahead of this year but this year is going well south of 60N and progs look favorable.  So far Oct 2017 is doing well for increased odds of a -AO based on Cohen's theory. Unfortunately, we've been fooled once or twice or thrice recently so does any of this really matter? I think there is some merit (probably more than we think after getting fooled) but I've formed a bit of a theory as to why it seems to not work so well.

2014 was a SLAM DUNK based on the SAI theory but the end result was pretty lame. We did get a -AO in Jan but the winter on the whole was definitely not "blocky" in the AO/NAO domain. The bigger story in 13-14 and 14-15 was the persistent -EPO. Cohen spun this well because the -EPO did produce cold in the areas that support his SAI theory but nobody can ever convince me that this was a case of "right for the wrong reasons". A quote from Cohen's blog at the beginning of Oct is what got my gears turning about why the SAI/-AO correlation has been off the last few years:

"Arctic sea ice reached its annual minimum on September 13th. Despite that Arctic sea ice is now growing, large swaths of the North Pacific side of the Arctic basin are ice-free (Figure 11). Recent research has shown that regional anomalies are important and the sea ice region most highly correlated with the winter AO is the Barents-Kara seas region where low Arctic sea ice favors a negative winter AO. However it is early and the magnitude of winter sea ice anomalies in the Barents Kara Seas and other seas in the Arctic are not currently known.  Given that sea ice is running below normal, this currently favors more extensive Siberian snow cover in the coming weeks, followed by a strengthened Siberian high and a weakened polar vortex/negative AO this upcoming winter."

 

The thing is, the low ice area in the Barents and Kara Seas are pretty much guaranteed almost EVERY year now. Unless arctic sea ice makes some sort of unprecedented comeback, low ice volume in this region during the Fall will continue indefinitely. If this anomaly is causing increased Siberian snowcover (seems like it might) then we should have a -AO almost every winter (which we aren't). See where I'm coming from? The current sea ice over the last 10 years has gone through rapid and substantial changes but Cohen's research stretches back many years before that. So my theory is that the SAI theory pre-2007 probably works much better than post 2007. Especially post 2012. I'm probably over simplifying this but it makes sense in my head. If the SAI is grounded on Siberian snowcover in Oct over large time scales but there has been significant changes in weather patterns due to reduced sea ice volume that can't recover to 1980-2010 climo then the entire premise is probably permanently flawed. That's my theory and I'm sticking to it. lol

 

How dare you!

 

[ORH_wxman]

There was a theory for a few years (esp 2009-2011 when the AO was basically nonstop negative) that the perennial sea ice deficit in the Barents/Kara was going to cause a "permanent -AO/NAO"...I think there was actually a peer reviewed paper that came out about it around 2012 or 2013. But obviously things flipped. The North Atlantic cooled drastically during the spring of 2013 and ever since then, we can't buy a -NAO/AO pattern in the winter except in brief spurts...a slightly longer spurt occurred in January 2016. The cold is not as robust in the north atlantic this year for the first time in years, so perhaps that will have some influence on the NAO...it is hard to say. I generally don't think SSTs in extratropical regions have a massive influence but do admit that they have some.

 

Maybe the SAI will do a little better this year without that massive area of ice bath water in the N ATL this year. But there could definitely be more factors that were hindering the formation of the -AO/NAO pattern than just that cold pool. In contrast, the N PAC has been cooling off quite a bit recently and one has to wonder if that will have some influence on the persistent -EPO we've been getting. We're still not nearly to the level of cold up there that we had during the deep -PDO period of 2007-2012, but it's not nearly as warm as the past 4 winters.

[Bob Chill]

12 minutes ago, ORH_wxman said:

There was a theory for a few years (esp 2009-2011 when the AO was basically nonstop negative) that the perennial sea ice deficit in the Barents/Kara was going to cause a "permanent -AO/NAO"...I think there was actually a peer reviewed paper that came out about it around 2012 or 2013. But obviously things flipped. The North Atlantic cooled drastically during the spring of 2013 and ever since then, we can't buy a -NAO/AO pattern in the winter except in brief spurts...a slightly longer spurt occurred in January 2016. The cold is not as robust in the north atlantic this year for the first time in years, so perhaps that will have some influence on the NAO...it is hard to say. I generally don't think SSTs in extratropical regions have a massive influence but do admit that they have some.

 

Maybe the SAI will do a little better this year without that massive area of ice bath water in the N ATL this year. But there could definitely be more factors that were hindering the formation of the -AO/NAO pattern than just that cold pool. In contrast, the N PAC has been cooling off quite a bit recently and one has to wonder if that will have some influence on the persistent -EPO we've been getting. We're still not nearly to the level of cold up there that we had during the deep -PDO period of 2007-2012, but it's not nearly as warm as the past 4 winters.

Interesting. I'm surprised I don't remember the permanent -AO talk. Weenie radar usually locks into that sort of talk. lol

I noticed the N Atl as well. I totally agree that it's unlikely to be some sort of strong driver or "easy indicator" but it's probably some sort of cryptic clue. I'm not mad at the big cold pool disappearing. That's for sure. lol.  I remember reading either you or Coastal talking about the epac warm pool and how it's unlikely that difference between 45 and 50 degree water probably has limited impact and that makes a lot of sense to me. Persistence caused the pool so it's probably more the end result of persistence. And maybe once the water temps reach a certain threshold it can help reinforce the persistence. Some sort of feedback loop or whatever. Definitely over my head either way. 

We've been on a heck of a +AO/NAO run though. 83-93 was a pretty big run of +AO/NAO winters with a few exceptions. There seems to be some sort of longer term cycle baked in there somewhere but I haven't a clue as to why. You would think that the current run we're on is going to flip here shortly. Maybe not this year but one of the upcoming winters will likely flip to stout blocking. You can only run one way for so long before regressing.

Another thing you and Coastal say that I really like is weather will be weather sometimes regardless of everything else. Getting hung up on an index or analog or whatever can only provide so much in the value dept. Surprises will always happen. 

[ORH_wxman]

18 minutes ago, Bob Chill said:

Interesting. I'm surprised I don't remember the permanent -AO talk. Weenie radar usually locks into that sort of talk. lol

I noticed the N Atl as well. I totally agree that it's unlikely to be some sort of strong driver or "easy indicator" but it's probably some sort of cryptic clue. I'm not mad at the big cold pool disappearing. That's for sure. lol.  I remember reading either you or Coastal talking about the epac warm pool and how it's unlikely that difference between 45 and 50 degree water probably has limited impact and that makes a lot of sense to me. Persistence caused the pool so it's probably more the end result of persistence. And maybe once the water temps reach a certain threshold it can help reinforce the persistence. Some sort of feedback loop or whatever. Definitely over my head either way. 

We've been on a heck of a +AO/NAO run though. 83-93 was a pretty big run of +AO/NAO winters with a few exceptions. There seems to be some sort of longer term cycle baked in there somewhere but I haven't a clue as to why. You would think that the current run we're on is going to flip here shortly. Maybe not this year but one of the upcoming winters will likely flip to stout blocking. You can only run one way for so long before regressing.

Another thing you and Coastal say that I really like is weather will be weather sometimes regardless of everything else. Getting hung up on an index or analog or whatever can only provide so much in the value dept. Surprises will always happen. 

Yeah, and I will say in addition to "surprises happen", it pays IMHO to look at the pattern with eyes rather than just index numbers and spreadsheets. While I have always been big into statistics and numbers, they can only tell us so much about the atmosphere from a sensible wx standpoint. Sometimes they are either misleading or don't glean enough info to make an accurate assessment of the medium term weather implications. Good old fashioned synoptic analysis can sometimes be a real boon to improving accuracy.

Most of us are in this for the anomalous side of winter wx anyways....we wait for anomalies. Not the mundane. So even though La Nina is not very good news for the mid-atlantic, you still watch and wait....hope for the anomaly to happen. We remember those anomalies with fond memories...1995-1996 was not only the biggest La Nina anomaly in terms of sensible wx, but also winter anomaly of all years in how prolific it was (at least until 2009-2010 for your area). I can guarantee nobody would have predicted that type of winter looking at ENSO charts and the recent state of the AO/NAO (the previous 8 consecutive winters had put up a +NAO).

[BTRWx]

On 10/11/2017 at 10:03 PM, mitchnick said:

I'll say this much, the top 4 years on todays super ensembles map were awfully blocky that winter: 68/69, 95/96 n 63/64 & 77/78. We can hope.

It's amazing how the years you mentioned are still showing up in a big way! We need to take frequent screen shots of this post as it auto-updates!

[mitchnick]

8 hours ago, BTRWx said:

It's amazing how the years you mentioned are still showing up in a big way! We need to take frequent screen shots of this post as it auto-updates!

Careful, you'll be "branded' a weenie for posting that map if it shows great years and praised as an intellectual if it has lousy ones. Lol

[CAPE]

GEFS continues to advertise a chilly look for late month. Builds a decent (south)east-based blocking ridge. Lets hope this is a glimpse of whats to come later. Maybe this will be the winter that features a return of persistent NA blocking. We are likely gonna need it.

[showmethesnow]

Thought I would look into our possibilities for the early part of the winter (Nov-Dec). Considering blocking (-NAO) will be key as far as our winter chances in our current ENSO state I decided I would dive specifically into past NAO's states to see if we might glean a clue as what to expect. I actually found some interesting things. 

 

***For clarity sake (Neg NAO -.5 or less) (Neutral NAO between -.5 through +.5) (Pos Nao +.5 or greater) ***  

Since 1950 we have seen 21 years that fit our current ENSO state (I used -.5 values and less). What we have seen...

9 winters with a -NAO in November (50-51, 55-56, 70-71, 73-74, 74-75, 83-84, 95-96, 00-01, 10-11), 2 winters with +NAO in November (99-00, 11-12) and 10 winters with a Neutral NAO for November (51-52, 64-65, 71-72, 75-76, 84-85, 88-89, 05-06, 07-08, 08-09, 16-17). So roughly a 45% chance of a neg, 45% of a neutral, 10% of a positive.

Of the 9 -NAO Novembers we also saw 4 that featured a -NAO December (50-51, 95-96, 00-01, 10-11), 4 with a neutral December (55-56, 70-71, 73-74, 83-84) and one with a positive December (74-75). 

Of the 10 Neutral NAO Novembers we saw 8 that followed with a Neutral NAO for December (64-65, 71-72, 75-76, 84-85, 88-89, 07-08, 08-09, 16-17). One -NAO (05-06) and one +NAO (54-55)

Of the 2 +Nao Novembers both also featured a +NAO in December (99-00, 11-12).

So what the above tells me is that...

We will most likely know early on what our chances are for the first part of winter.

No -NAO in November and chances are extremely high we lose much of the first half of winter. 

A Neutral NAO in November strongly suggests a followup neutral in December.

A Negative Enso (-.5 or more) rarely features a plus NAO in either Nov or December. (6 out of 44 months)

I did delve a little into the NAO state for the second half of winter (Jan/Feb) going by the Nov/Dec NAO state and found for the most part it is inconclusive. One thing I did notice, but with a sample size of only 2 years take it for what it is worth, is that if we see a +NAO in both Nov/Dec we fail to see a -NAO in the second half of winter.

***************************************************************************************************

After looking over the NAO states for Nov/Dec I was curious if we could possibly get a clue as to Novembers NAO by looking at October composites and comparing to the 500mb for the first half of this October in conjunction with both the GFS and Euro output for the coming two weeks. This should give us a rough idea of what the overall October 500mb look will be.

As far as the GFS and Euro output I will leave that to you to pull up and extrapolate onto the 500 mb image for the first 11 days of October below.

 

500mb for Oct 1-Oct 11

 

Now below are the composites for the different NAO states for both Nov and Nov/Dec to compare to.

 

Neg NAO in November

 

Neutral NAO in November

 

Positive NAO in November

 

Negative NAO for both Nov/Dec

 

Negative NAO November/Neutral NAO December

 

Not much value with only one year but...

Negative NAO November/Positive NAO December

 

Neutral November/Neutral December

 

Again only one year

Neutral November/Negative December

 

one year

Neutral November/Positive December

 

Have my father-in-law visiting so have limited time so I myself have only had a cursory glance to compare but will look a little deeper into it later today. Will be interesting to see at the end of October how this all compares though.

[showmethesnow]

2 hours ago, mitchnick said:

Careful, you'll be "branded' a weenie for posting that map if it shows great years and praised as an intellectual if it has lousy ones. Lol

You were good with me. It was weather related and we had a little fun with it. I highly doubt anybody was taking it seriously though. Sure beats what I was seeing in a couple other winter threads with the constant irrelevant banter. And considering the board has been for the most part dead, as we all wait to see the state of the NAO, I saw no harm in it and can't understand why some would.

[showmethesnow]

2 hours ago, C.A.P.E. said:

GEFS continues to advertise a chilly look for late month. Builds a decent (south)east-based blocking ridge. Lets hope this is a glimpse of whats to come later. Maybe this will be the winter that features a return of persistent NA blocking. We are likely gonna need it.

Actually am liking the look we are seeing on both the GEFS and the Eps in the extended (The GEFS more so then the EPS). The look suggests building heights into the Greenland region for the start of November. But as we all know, how often have we seen a building -NAO in the extended only to see it pushed back time and again?

[BTRWx]

3 hours ago, mitchnick said:

Careful, you'll be "branded' a weenie for posting that map if it shows great years and praised as an intellectual if it has lousy ones. Lol

I prefer those over the randomness from CIPS imo.

[mitchnick]

1 hour ago, showmethesnow said:

Actually am liking the look we are seeing on both the GEFS and the Eps in the extended (The GEFS more so then the EPS). The look suggests building heights into the Greenland region for the start of November. But as we all know, how often have we seen a building -NAO in the extended only to see it pushed back time and again?

Purely anecdotal,  but when I see snow falling imby in November,  even if it is just flurries,  I usually have an AN snowfall winter. October can furnace all it wants so long as we get a flip in November. 

[showmethesnow]

1 hour ago, mitchnick said:

Purely anecdotal,  but when I see snow falling imby in November,  even if it is just flurries,  I usually have an AN snowfall winter. October can furnace all it wants so long as we get a flip in November. 

I can't recall a decent winter let alone a good one whenever I have seen snow in October. So I am with you, it can torch in October for all I care.