Winter 15-16 Discussion

[tonysc]

Three degrees below normal and 200% of normal snowfall??!!  Sign me up!

Actually if you look at the graph key to the right, it doesn't just say -3 degrees, it says -3 to -5 degrees. So could be even better.

[Brick Tamland]

This pretty much sums up the forecasting challenges for nc.

Pretty much when it comes to everything these days. Snow, severe storms, hurricanes. Hot or cold and dry is pretty much the only given.

[griteater]

The AO has been negative since late June.  Piggybacking off some numbers produced by WSI and @antmasiello, I looked at some multi month summer-fall correlations to the winter AO during El Ninos.  The strongest correlation I found was this...during El Ninos, the sign of the July-Sept averaged AO matched the sign of the AO during the subsequent winter (Dec-Mar) in 18 of the 22 cases (since 1950).  Now, there were cases where the AO was barely negative / barely positive, or essentially neutral, but nevertheless the correlation stands as stated.  It looks likely that the Jul-Sep AO will average negative.  The way I would interpret this is not so much that the winter AO will average negative or strongly negative, but rather, that these stats indicate an increased likelihood that the winter averaged AO won't be substantially positive like it was last winter.

 

[Met1985]

Grit I was thinking the same thing about the nao also. I wonder if that same analysis could be applied to it also. Sure it is not a sure thing but interesting non the less.

[griteater]

Grit I was thinking the same thing about the nao also. I wonder if that same analysis could be applied to it also. Sure it is not a sure thing but interesting non the less.

The correlations with the NAO weren't nearly as strong from what I saw 

[Met1985]

The correlations with the NAO weren't nearly as strong from what I saw

Ah ok. Thanks for the info Grit. Always posting great data.

[packbacker]

Actually if you look at the graph key to the right, it doesn't just say -3 degrees, it says -3 to -5 degrees. So could be even better.

That's crazy cold considering that Dec will most likely be above avg which he is factoring in.

[BIG FROSTY]

So I'm looking at anywhere from 20-30 inches of snow   I could live with that!!!  

[stadiumwave]

Check this out...this is amazing to me:


500mb last 6 Winters


Clearly the cause for the colder winters east of the Rockies has been an increase in high latitude blocking from the Pacific side (EPO), Atlantic side (NAO), & over the ARCTIC (AO).  It's been a combination, but what's incredible is it's becoming increasingly rare to have a winter that doesn't have high latitude blocking somewhere.

Here's 500mb during 1986 to 2000 winters:



Temps for 1986-2000 winters



Here's the 500mb during 2001-2015 winters:



Temps for 2001-2015 winters


And the winter cooling trend & increase in blocking has occurred during La Nina & El Nino's alike.

My interest is why has there been such a gradual increase the last 10-15 years of high latitude blocking on the PAC (EPO) side,  the ATL side (NAO), & AO?  Is the cause:


(A) more waters being exposed during ARCTIC SEA melt seasons


( lower solar activity


©warmer oceans


(D) combination of all three


(E) blind luck


I'm not making implications for this other than for whatever reason, we are in a period that is more favorable to colder/snowier winters east of the Rockies...basically due to the increase in various forms of high latitude blocking.  That doesn't mean we will have a cold/snowy winter this winter east of the Rockies but it's interesting nonetheless.

[CAD_Wedge_NC]

My interest is why has there been such a gradual increase the last 10-15 years of high latitude blocking on the PAC (EPO) side,  the ATL side (NAO), & AO?  Is the cause:


(A) more waters being exposed during ARCTIC SEA melt seasons


( lower solar activity


©warmer oceans


(D) combination of all three


(E) blind luck

 

 

 

I believe you are on the right track...... lower sea ice and overall warmer Pacific waters have contributed to a +PNA / -EPO couplet. Thus a colder East / Southeast...... High latitude blocking could be the result of lower solar out-put. There is on-going research to establish the correlation.

[pcbjr]

The AO has been negative since late June.  Piggybacking off some numbers produced by WSI and @antmasiello, I looked at some multi month summer-fall correlations to the winter AO during El Ninos.  The strongest correlation I found was this...during El Ninos, the sign of the July-Sept averaged AO matched the sign of the AO during the subsequent winter (Dec-Mar) in 18 of the 22 cases (since 1950).  Now, there were cases where the AO was barely negative / barely positive, or essentially neutral, but nevertheless the correlation stands as stated.  It looks likely that the Jul-Sep AO will average negative.  The way I would interpret this is not so much that the winter AO will average negative or strongly negative, but rather, that these stats indicate an increased likelihood that the winter averaged AO won't be substantially positive like it was last winter.

 

Rubber band? January?

[stadiumwave]

My interest is why has there been such a gradual increase the last 10-15 years of high latitude blocking on the PAC (EPO) side,  the ATL side (NAO), & AO?  Is the cause:

(A) more waters being exposed during ARCTIC SEA melt seasons

( lower solar activity

©warmer oceans

(D) combination of all three

(E) blind luck

 

 

 

I believe you are on the right track...... lower sea ice and overall warmer Pacific waters have contributed to a +PNA / -EPO couplet. Thus a colder East / Southeast...... High latitude blocking could be the result of lower solar out-put. There is on-going research to establish the correlation.

Thanks for the response. If anyone catches wind of any recent journal publications on the subject PM me or post it. Thanks

[LithiaWx]

Check this out...this is amazing to me:500mb last 6 WintersClearly the cause for the colder winters east of the Rockies has been an increase in high latitude blocking from the Pacific side (EPO), Atlantic side (NAO), & over the ARCTIC (AO).  It's been a combination, but what's incredible is it's becoming increasingly rare to have a winter that doesn't have high latitude blocking somewhere.Here's 500mb during 1986 to 2000 winters:Temps for 1986-2000 wintersHere's the 500mb during 2001-2015 winters:Temps for 2001-2015 wintersAnd the winter cooling trend & increase in blocking has occurred during La Nina & El Nino's alike.My interest is why has there been such a gradual increase the last 10-15 years of high latitude blocking on the PAC (EPO) side,  the ATL side (NAO), & AO?  Is the cause:(A) more waters being exposed during ARCTIC SEA melt seasons( lower solar activity©warmer oceans(D) combination of all three(E) blind luckI'm not making implications for this other than for whatever reason, we are in a period that is more favorable to colder/snowier winters east of the Rockies...basically due to the increase in various forms of high latitude blocking.  That doesn't mean we will have a cold/snowy winter this winter east of the Rockies but it's interesting nonetheless.

There have been papers published that try to link lower sea ice in the fall over the Kara sea with an increase in - NAO patterns. IMO solar is a complete farce, has little to no impact. More and more papers are being released that take the air out of the solar arguments. As for warmer waters? Meh...could be... It also could be nothing in particular and just coincidental.

[stadiumwave]

There have been papers published that try to link lower sea ice in the fall over the Kara sea with an increase in - NAO patterns. IMO solar is a complete farce, has little to no impact. More and more papers are being released that take the air out of the solar arguments. As for warmer waters? Meh...could be... It also could be nothing in particular and just coincidental.

All the solar papers practically downplaying any role of the sun in climate activity this year are nothing but PR papers leading to climate Summitt in Paris. Since deniers cry "solar" hence the studies to dismiss but that's another subject in itself.

Plus I think you misunderstand my solar connection. When solar activity is high, in a nut shell...it cools the Northern Hemispheric stratosphere. This strengthens the stratospheric vortex making it less likely to have a stratospheric warming event (ssw) that would displace the PV & the cold Arctic air. Strong PV spells +AO/+NAO.

But low solar activity increases the chance of a weaker stratospheric PV & a greater chance of SSW's, high latitude blocking of the Arctic & cold air intrusions.

As I posted the data, it's pretty clear that high latitude blocking has increased the last 15 years. Can't help but think declining solar activity played some type of role in the increase in blocking. Look at the monster blocking in 2009-10 winter...on the heels of the end of that solar cycle & a blank sun for months.

[griteater]

stadium - some thoughts on your post...

 

1. 1989-1995 was a period of strongly positive AO/NAO winters, aided by low ozone and high volcanic aerosols from the Mt. Pinatubo eruption:

http://www.nasa.gov/centers/goddard/news/topstory/2003/0306aopin.html

http://climate.envsci.rutgers.edu/pdf/StenchikovEtAl2002JD002090.pdf

 

2. Since 2000, there have actually been 7 +AO winters (Dec-Mar) and 5 -AO winters, so no notable trend there...but yes, we've seen persistent NE Pac / W North America ridging over the past few winters.

 

3. I've read mixed signals regarding arctic sea ice loss and high latitude blocking.  You may be interested in these if you haven't seen them: 

https://www.youtube.com/watch?v=4spEuh8vswE

http://www.motherjones.com/environment/2014/02/inquiring-minds-jennifer-francis-kevin-trenberth-jet-stream-winter

 

4. Regarding solar, I don't think it's fair to say that overall declining solar cycles have had a big impact on high latitude blocking, but I have a follow-up below related to times when the individual solar cycles are at their minimum.

[griteater]

There have been papers published that try to link lower sea ice in the fall over the Kara sea with an increase in - NAO patterns. IMO solar is a complete farce, has little to no impact. More and more papers are being released that take the air out of the solar arguments. As for warmer waters? Meh...could be... It also could be nothing in particular and just coincidental.

It depends on how it is used.  If talking about solar and global temperatures, that's covered in the climate forum.  If talking about solar and high latitude blocking, there is a specific scenario that has historically delivered -AO/-NAO winters.  Since 1950, there have been 5 winters in which the following combination has occurred....1) Front end of the -QBO (45mb), and 2) Solar minimum (i.e. low solar flux).  The AO & NAO were decidedly negative in all 5 winters ('63, '77, '87, '96, '10)....and those results match up well with the research on this topic:

http://journals.ametsoc.org/doi/pdf/10.1175/JAS-3297.1

https://www.terrapub.co.jp/onlineproceedings/ste/CAWSES2007/pdf/CAWSES_257.pdf

[Bob Chill]

Nice posts, Grit. No matter which way you slice it, the processes in the atmosphere are far too complicated to try and isolate a couple pieces and draw reliable conclusions that allow for accurate long range predictions. If it were possible, the extremely powerful computers and software in use today would be reliable at the ranges we like to speculate on season after season. Humans and computers fall far short of being reliable predictors at seasonal ranges. And for good reasons too. 

 

Of course there are certain generalizations that are usually fairly accurate when having a significant enso event. Mod+ nino's and nina's are fairly easy to make long range guesses irt storm tracks and general areas of anomalous precip. I'd be quite surprised if the majority of the southern tier and parts of the east coast don't come in with a solid + precip anomaly during DJFM. Also, the conus as a whole will likely be warmer than the last 2 years. Going beyond that is far above my pay grade. lol. 

[Met1985]

It depends on how it is used. If talking about solar and global temperatures, that's covered in the climate forum. If talking about solar and high latitude blocking, there is a specific scenario that has historically delivered -AO/-NAO winters. Since 1950, there have been 5 winters in which the following combination has occurred....1) Front end of the -QBO (45mb), and 2) Solar minimum (i.e. low solar flux). The AO & NAO were decidedly negative in all 5 winters ('63, '77, '87, '96, '10)....and those results match up well with the research on this topic:

http://journals.ametsoc.org/doi/pdf/10.1175/JAS-3297.1

https://www.terrapub.co.jp/onlineproceedings/ste/CAWSES2007/pdf/CAWSES_257.pdf

Also from some of the most recent years like 2012-13 and last year we had very little blocking in the ao and nao regions. Some say solar activity may have played a role in both those years because in the fall we had some pretty active solar activity. I think it would be fullish to totally discount solar activity as being a non factor.

[stadiumwave]

Also from some of the most recent years like 2012-13 and last year we had very little blocking in the ao and nao regions. Some say solar activity may have played a role in both those years because in the fall we had some pretty active solar activity. I think it would be fullish to totally discount solar activity as being a non factor.

Bingo! The last 2 years leading up to fall it appeared things were conducive for -AO/-NAO until late fall solar activity spikes ruined it...2 years in a row.

[stadiumwave]

stadium - some thoughts on your post...

 

1. 1989-1995 was a period of strongly positive AO/NAO winters, aided by low ozone and high volcanic aerosols from the Mt. Pinatubo eruption:

http://www.nasa.gov/centers/goddard/news/topstory/2003/0306aopin.html

http://climate.envsci.rutgers.edu/pdf/StenchikovEtAl2002JD002090.pdf

 

2. Since 2000, there have actually been 7 +AO winters (Dec-Mar) and 5 -AO winters, so no notable trend there...but yes, we've seen persistent NE Pac / W North America ridging over the past few winters.

 

3. I've read mixed signals regarding arctic sea ice loss and high latitude blocking.  You may be interested in these if you haven't seen them: 

http://www.motherjones.com/environment/2014/02/inquiring-minds-jennifer-francis-kevin-trenberth-jet-stream-winter

 

4. Regarding solar, I don't think it's fair to say that overall declining solar cycles have had a big impact on high latitude blocking, but I have a follow-up below related to times when the individual solar cycles are at their minimum.

On #2...remember Blocking in the EPO region is high latitude blocking also. Like I said if you read my original post "carefully"...the high latitude blocking increase since 2001-15 HAS NOT just been a -ao/-nao blocking pattern every year. If you thought thats what I was saying you misunderstood.

It just seems that the likelihood for one or the other has increased as per the 500mb I posted.

[griteater]

On #2...remember Blocking in the EPO region is high latitude blocking also. Like I said if you read my original post "carefully"...the high latitude blocking increase since 2001-15 HAS NOT just been a -ao/-nao blocking pattern every year. If you thought thats what I was saying you misunderstood.

It just seems that the likelihood for one or the other has increased as per the 500mb I posted.

Fair point...yes, there have been more blocking patterns somewhere up north (EPO/AO/NAO) since 2000, compared to the 90's.

[griteater]

Also from some of the most recent years like 2012-13 and last year we had very little blocking in the ao and nao regions. Some say solar activity may have played a role in both those years because in the fall we had some pretty active solar activity. I think it would be fullish to totally discount solar activity as being a non factor.

Bingo! The last 2 years leading up to fall it appeared things were conducive for -AO/-NAO until late fall solar activity spikes ruined it...2 years in a row.

Also had a solar spike in the fall of 2011, with deathly +AO that winter.  

[burgertime]

Nice posts, Grit. No matter which way you slice it, the processes in the atmosphere are far too complicated to try and isolate a couple pieces and draw reliable conclusions that allow for accurate long range predictions. If it were possible, the extremely powerful computers and software in use today would be reliable at the ranges we like to speculate on season after season. Humans and computers fall far short of being reliable predictors at seasonal ranges. And for good reasons too. 

 

Of course there are certain generalizations that are usually fairly accurate when having a significant enso event. Mod+ nino's and nina's are fairly easy to make long range guesses irt storm tracks and general areas of anomalous precip. I'd be quite surprised if the majority of the southern tier and parts of the east coast don't come in with a solid + precip anomaly during DJFM. Also, the conus as a whole will likely be warmer than the last 2 years. Going beyond that is far above my pay grade. lol. 

 

I've always felt we need to crack the Many World's theory of quantum mechanics. There are literally so many outcomes from so many minor changes in the atmosphere in the long range. 

[stadiumwave]

Also had a solar spike in the fall of 2011, with deathly +AO that winter.

The winter that most of us would love to forget & hope to never relive. But I'm sure if I live long enough I will

[griteater]

Grit I was thinking the same thing about the nao also. I wonder if that same analysis could be applied to it also. Sure it is not a sure thing but interesting non the less.

The correlations with the NAO weren't nearly as strong from what I saw 

 

Coming back to this Met....the Jul-Sep NAO to winter NAO correlation wasn't strong....but when I went back and looked at the Jul-Sep AO to see how well it correlated to the winter NAO, I found that there was a high correlation (18 of 22).  So, bottom line, during El Ninos, the sign of the Jul-Sep AO matched the sign of the subsequent winter's AO <AND> NAO in 18 of 22 cases.

 

[Snowless in Carrollton]

The winter that most of us would love to forget & hope to never relive. But I'm sure if I live long enough I will

honestly I loved that winter. A million times better than last winter around here. Didn't have to worry about getting my hopes up for snow because we never had any chances ! Last winter was by far the most depressing winter in my lifetime.

[Met1985]

Also had a solar spike in the fall of 2011, with deathly +AO that winter.

Yeah I forgot about that winter 2011-12 was absolutely awful with no blocking at all that wintet. I remember I had 13 inches the whole winter. Pathetic for the mountains.

[Met1985]

Coming back to this Met....the Jul-Sep NAO to winter NAO correlation wasn't strong....but when I went back and looked at the Jul-Sep AO to see how well it correlated to the winter NAO, I found that there was a high correlation (18 of 22). So, bottom line, during El Ninos, the sign of the Jul-Sep AO matched the sign of the subsequent winter's AO <AND> NAO in 18 of 22 cases.

Very cool and great analysis Grit. Hopefully that correlates to some good blocking this winter from the ao and nao regions as both look to stay mostly negative heading into September. Again thanks for the feedback Grit!

[LithiaWx]

All the solar papers practically downplaying any role of the sun in climate activity this year are nothing but PR papers leading to climate Summitt in Paris. Since deniers cry "solar" hence the studies to dismiss but that's another subject in itself.

Plus I think you misunderstand my solar connection. When solar activity is high, in a nut shell...it cools the Northern Hemispheric stratosphere. This strengthens the stratospheric vortex making it less likely to have a stratospheric warming event (ssw) that would displace the PV & the cold Arctic air. Strong PV spells +AO/+NAO.

But low solar activity increases the chance of a weaker stratospheric PV & a greater chance of SSW's, high latitude blocking of the Arctic & cold air intrusions.

As I posted the data, it's pretty clear that high latitude blocking has increased the last 15 years. Can't help but think declining solar activity played some type of role in the increase in blocking. Look at the monster blocking in 2009-10 winter...on the heels of the end of that solar cycle & a blank sun for months.

I don't know of any scientific peer reviewed data that links solar to anything you just wrote.

[weathertree4u]

Well...the last 2 winters in Kentucky have been absolutely epic. The best back to back winters since the late 70's in my location.  I'd settle for average here in Ky & let it be epic for the SE winter lovers.

Yea, so far, the last few winters, the Nashville area has gotten missed either to the North or the South so would love to have a winter that it actually snows some.