And we begin

[WXeastern]

Transmission hasnt failed and it likely wont in respect to the data..you seem to be assuming quite a bit!! Are you basing your argument off of October stratospheric temps or stratospheric temps that havent even occured yet? Its only November 8th and Im sure you know that Stratospheric temps is the main driver of the PV/AO.. therefore the same correlation I mention above argues pretty strongly against any major and longterm November-December stratospheric cooling!

[skierinvermont]

Transmission hasnt failed and it likely wont in respect to the data..you seem to be assuming quite a bit!! Are you basing your argument off of October stratospheric temps or stratospheric temps that havent even occured yet? Its only November 8th and Im sure you know that Stratospheric temps is the main driver of the PV/AO.. therefore the same correlation I mention above argues pretty strongly against any major and longterm November-December stratospheric cooling!

The stratosphere is already cold. In most of the years you mentioned, it was warm. In the years that it wasn't warm, the AO was positive. This will likely be one such year.

[WXeastern]

The stratosphere is already cold.

No..not really..in fact its not that much different from the mean anomaly of all those -AO years you posted above. It takes alot more cooling than that small bubble of cooler air over Asia to drive up a strong PV that will hold the Arctic Oscillation in positive territory! The stratospheric temps that caused such a negative AO in October are still pretty much there and havent moved.

[Bob Chill]

The stratosphere is already cold. In most of the years you mentioned, it was warm. In the years that it wasn't warm, the AO was positive. This will likely be one such year.

I understand what you're saying but I think it's precarious at best to make this kind of call. It's too easy to find differing outcomes based on the current state of the strat temps.

I'm far from an expert on this stuff but I've followed the strat ssw threads for the last couple years. Expected outcomes seem to be equally matched with busts.

Here's the 2012 graph:

The big standout with the snowcover data is definitely 06-07. It was a way positive ao/nao year. There was a substantial ssw in Jan that appears to have some relation to the flip to a negative ao late in the season. It was too little too late for many but here's what 2006 looked like leading into winter:

And here's 2007 with the big ssw:

Then you can definitely make the argument that a warmer Nov strat helped in 09-10 which saw record -ao and blocking:

But then in 02-03 there was a big -ao in Nov-Dec and a modest one in Jan but the strat temp behavior is very similar to 2012 so far:

[NJwinter23]

I understand what you're saying but I think it's precarious at best to make this kind of call. It's too easy to find differing outcomes based on the current state of the strat temps.

I'm far from an expert on this stuff but I've followed the strat ssw threads for the last couple years. Expected outcomes seem to be equally matched with busts.

Here's the 2012 graph:

The big standout with the snowcover data is definitely 06-07. It was a way positive ao/nao year. There was a substantial ssw in Jan that appears to have some relation to the flip to a negative ao late in the season. It was too little too late for many but here's what 2006 looked like leading into winter:

And here's 2007 with the big ssw:

Then you can definitely make the argument that a warmer Nov strat helped in 09-10 which saw record -ao and blocking:

But then in 02-03 there was a big -ao in Nov-Dec and a modest one in Jan but the strat temp behavior is very similar to 2012 so far:

We've been through this discussion with these charts and past years (particularly skiervermont has) recently with other posters. I'd recommend looking at the hemispheric views available on the ESRL site, from the same view that skier's correlation map shows...and compare that way.

The stratosphere does not look very favorable to me either (for -AO purposes) at the moment. Im not ready to throw in the towel on December here as it can still recover late novy, ESPECIALLY given the snow cover advancement we saw and given 2010 as a recent late novy warming example....but the model predictions to day 15 do not looks very good right now.

[skierinvermont]

We've been through this discussion with these charts and past years (particularly skiervermont has) recently with other posters. I'd recommend looking at the hemispheric views available on the ESRL site, from the same view that skier's correlation map shows...and compare that way.

The stratosphere does not look very favorable to me either (for -AO purposes) at the moment. Im not ready to throw in the towel on December here as it can still recover late novy, ESPECIALLY given the snow cover advancement we saw and given 2010 as a recent late novy warming example....but the model predictions to day 15 do not looks very good right now.

Well said. While 02-03 had a cold Nov Strat overall, there was a large warm bubble over Asia which is where the correlation and causation for a -AO is. Hence the -AO 02-03. The rest of the stratosphere outside the Asia region does not matter.

This year has no such warm bubble. The stratosphere looks as it does preceding +AO Decembers and Januaries. Cold over Asia.

The time series graphs that are often used on here are a horrible indicator. They are for the whole stratosphere but only near Asia matters.

[nzucker]

According to HM, an upper high over the Aleutians is going to be warming the stratosphere as we go forward. Here is what he said, "That's one heck of a MJO signal in the CHI fields. Notice ALL modeling was wrong with weakening the wave as some us warned would happen. The wave clearly is and has been under-represented. Recent East-Asian torque has ignited a wave 1 response and a possible Aleutian High / warming in the lower-mid stratosphere in days 6-10. This is no 2011-12 winter coming..."

[Bob Chill]

Well said. While 02-03 had a cold Nov Strat overall, there was a large warm bubble over Asia which is where the correlation and causation for a -AO is. Hence the -AO 02-03. The rest of the stratosphere outside the Asia region does not matter.

This year has no such warm bubble. The stratosphere looks as it does preceding +AO Decembers and Januaries. Cold over Asia.

The time series graphs that are often used on here are a horrible indicator. They are for the whole stratosphere but only near Asia matters.

Thanks for clarifying. I was clearly behind the curve on the methodology. I did a bunch of +AO data crunching last year so I had my spreads on hand. I pulled Nov strat temp anoms for the +AO Decembers exceeding +1.5 and it does clearly show what you are talking about:

And the reverse with Dec -AO below -2.0:

I didn't spend much time with individual years but 2010 stands out:

December 2010 & January 2011 we're very negative AO months but the Nov strat was largely cold all over Asia and western NA. Did the warm anom over the N atlantic have anything impact? I'm not well versed in this topic at all but it is interesting.

[HM]

According to HM, an upper high over the Aleutians is going to be warming the stratosphere as we go forward. Here is what he said, "That's one heck of a MJO signal in the CHI fields. Notice ALL modeling was wrong with weakening the wave as some us warned would happen. The wave clearly is and has been under-represented. Recent East-Asian torque has ignited a wave 1 response and a possible Aleutian High / warming in the lower-mid stratosphere in days 6-10. This is no 2011-12 winter coming..."

That guy, I believe his name is Henry, is such a hypster ... oh wait a minute...

[nzucker]

December 2010 & January 2011 we're very negative AO months but the Nov strat was largely cold all over Asia and western NA. Did the warm anom over the N atlantic have anything impact? I'm not well versed in this topic at all but it is interesting.

I think a warm stratosphere over Greenland actually correlates with a +AO.

In Dec 2010 we had a strong PV, but it was displaced. It was sort of an unusual way of getting a cold pattern into the CONUS. We also had a legendary -NAO block that bled all the west to the Davis Strait, setting up the 12/26 Nor'easter. There may have been other factors in that block...North Atlantic SSTs, storm track, etc. I remember a cutter bombed out around 12/1 and again around 12/14, and those really strong cutters tend to pump up heights in the North Atlantic.

In terms of this year, the Euro monthlies are also developing the strong Aleutian ridge which extends back into Siberia. This type of upper ridge tends to warm the stratosphere. I think we could be looking at a very different picture by late November. This is perfect for our climo, as we're not likely to see much sustained cold/snow in early-mid November compared to a month later. I can say that despite the 8" I just received.

[skierinvermont]

December 2010 & January 2011 we're very negative AO months but the Nov strat was largely cold all over Asia and western NA. Did the warm anom over the N atlantic have anything impact? I'm not well versed in this topic at all but it is interesting.

2010 had a last minute flip that saved us. Nov averaged cold over Asia, but finished warm. It is always possible to get a late November warming, but something has to cause it, so usually there isn't one.

If HM is right, we might see one coming up which would be in time to save this Dec/Jan.

Compare this Nov 30 2010 to the November 2010 average you already posted:

[Mallow]

See stats on previous page. This chart sums it up pretty well too:

The correlation is weaker over Europe and western Russia, but... so far 2012 looks more like a -AO out there. And the correlation is not a whole lot stronger over eastern Russia.

On top of that, we only have 6 days of November data so far to look at. So... color me unconvinced (so far).

[Bob Chill]

2010 had a last minute flip that saved us. Nov averaged cold over Asia, but finished warm. It is always possible to get a late November warming, but something has to cause it, so usually there isn't one.

If HM is right, we might see one coming up which would be in time to save this Dec/Jan.

Compare this Nov 30 2010 to the November 2010 average you already posted:

Got it. Thank you. Hey, I really appreciate you and NJwinter helping me get on the right course to wrap my head around this stuff. I am definitely adding strat conditions to the list of the things I enjoy following.

[tacoman25]

2010 had a last minute flip that saved us. Nov averaged cold over Asia, but finished warm. It is always possible to get a late November warming, but something has to cause it, so usually there isn't one.

If HM is right, we might see one coming up which would be in time to save this Dec/Jan.

Compare this Nov 30 2010 to the November 2010 average you already posted:

FWIW, the Aleutian blocking pattern that appears will be a major feature this month was also present in Nov 2010.

[NJwinter23]

2010 had a last minute flip that saved us. Nov averaged cold over Asia, but finished warm. It is always possible to get a late November warming, but something has to cause it, so usually there isn't one.

If HM is right, we might see one coming up which would be in time to save this Dec/Jan.

Compare this Nov 30 2010 to the November 2010 average you already posted:

There appears to be similarities to mid-late Nov 2010 going on this year too.

If you look at 50 mb on 11/19/10, this is what you saw:

If you compare that to the day 6 European forecast at 50 mb (i cant post the images here), the temp anomalies look very similar with the elephant in the room over alaska and slight warming around europe.

At the same time in 2010 you had this 500mb map with the Aleutian ridge developing, and the stratosphere was saved in late november

Despite the predominently +AO regime we seem to be running into for the coming days and weeks, we do see a nice aleutian ridge by day 6, and perhaps that is a positive sign as HM/skiervermont have mentioned above.

[CoastalWx]

That's interesting NJWinter, I was going to post that the ensembles through the end of the period keep AK and NE Siberia very cold, but a pretty good warming over Europe and NW Russia. It also migrates the "coldest" anomalies to Hudson Bay by day 15. I know this is 50mb and not 70mb, but it may have an idea anyways.

[blizzard1024]

This is not good.... euro and gfs continue to insist that this positive NAO pattern

persists run after run. If this holds, we can write off the rest of November in the northeast,

unless the very end of the month there is a pattern change. Looks similar to

last year...except not quite as warm.

[jrodd321]

This is not good.... euro and gfs continue to insist that this positive NAO pattern

persists run after run. If this holds, we can write off the rest of November in the northeast,

unless the very end of the month there is a pattern change. Looks similar to

last year...except not quite as warm.

writing off the rest of November? Seriously? Do people expect big snowstorms in November? Come on man. Wake up.

Point is nothing is set in stone right now. And id rather have the NAO go positive in the last few weeks of November than have this happen the first week of December.

[blizzard1024]

writing off the rest of November? Seriously? Do people expect big snowstorms in November? Come on man. Wake up.

Point is nothing is set in stone right now. And id rather have the NAO go positive in the last few weeks of November than have this happen the first week of December.

The pattern is looking eerily similar to last November.....

[weathafella]

The pattern is looking eerily similar to last November.....

No it isn't. Please the North Pacific vs last year.

[Eskimo Joe]

I made an animation of the past 4 weeks of NH snow cover as analyzed from the Rutgers Global Snow Lab. The animation starts at Week 40 and terminates at Week 44. Here's the movie:

Area of Snow Extent

Northern Hemisphere:

11.23 million sq. km -> 30.15 million sq. km (+18.92 million sq. km)

Eurasia:

5.85 million sq. km -> 18.08 million sq. km (+12.23 million sq. km)

North America:

5.38 million sq. km -> 12.07 million sq. km (+6.69 million sq. km)

On the surface this seems to be a notable increase in snow cover, and the numbers seem to agree. Lets see what happens in the coming 4 - 6 weeks.

[Ginx snewx]

No it isn't. Please the North Pacific vs last year.

Alaska had a mega death vortex last year, there is an Aleutian ridge this year, not similar at all.

[WXeastern]

The pattern is looking eerily similar to last November.....

LOL.No not at all

12zGFS ensembles.higher latitude blocking ..active southern stream.

Not even close to last year at this time!! I wouldnt worry about the vortex in Alaska..as it was also there alot during the 09/10 winter

[blizzard1024]

LOL.No not at all

12zGFS ensembles.higher latitude blocking ..active southern stream.

Not even close to last year at this time!! I wouldnt worry about the vortex in Alaska..as it was also there alot during the 09/10 winter

I don't the like phase of the NAO. Yes the pacific is different. But it is so darn mild...especially across southern canada

in the next week or so. just impatience on my part. It has been a LONG time since I have enjoyed winter. No snowstorms last year at all

biggest snow was only 2.8 inches!!

Missed the recent nor'easter to the east. Sandy produced just rain here. So all we have had in snow so far is 0.2 inches.

It has been almost 18 months since I have seen a decent snowfall and I live in upstate NY!!!

[Analog96]

I don't the like phase of the NAO. Yes the pacific is different. But it is so darn mild...especially across southern canada

in the next week or so. just impatience on my part. It has been a LONG time since I have enjoyed winter. No snowstorms last year at all

biggest snow was only 2.8 inches!!

Missed the recent nor'easter to the east. Sandy produced just rain here. So all we have had in snow so far is 0.2 inches.

It has been almost 18 months since I have seen a decent snowfall and I live in upstate NY!!!

1) It's November. November really isn't that cold of a month.

2) It's going to be 5 to 10 BELOW zero in much of Montana tonight. That is pretty damn cold!

[blizzard1024]

1) It's November. November really isn't that cold of a month.

2) It's going to be 5 to 10 BELOW zero in much of Montana tonight. That is pretty damn cold!

I was hoping for some November lake effect snows at least. Where I live, November can be

snowy...especially the latter half of the month. I am NOT writing off the winter. That would be

crazy. It has been a long time since I have seen a decent November snow...many years.

[Mitchel Volk]

In the Northeast the weather pattern is taking a break after a wild period. The -NAO had to turn + for a period of time. Late November and early December will be a time to watch. If the NAO turns negative again then I think we are in for a wild winter. Looking at the forecast for 240 hours the models are hinting at a possible Nor-easter although at this point it does look like a rain storm. It is way too early to predict the winter period, especially after we just had a possible failure of an El Nino.

[nzucker]

I don't the like phase of the NAO. Yes the pacific is different. But it is so darn mild...especially across southern canada

in the next week or so. just impatience on my part. It has been a LONG time since I have enjoyed winter. No snowstorms last year at all

biggest snow was only 2.8 inches!!

Missed the recent nor'easter to the east. Sandy produced just rain here. So all we have had in snow so far is 0.2 inches.

It has been almost 18 months since I have seen a decent snowfall and I live in upstate NY!!!

The NAO does look very poor on both the 12z ECM and the 0z GFS. However, the 12z GEFS did show a block developing in the fantasy range. The 0z GEFS, out past hour 300, show a poleward extension of the Aleutian ridge and a -NAO block building, leading to lower heights in the East:

I don't think temperatures will be too far above average in the mid-Atlantic and Southern New England because there's a low height anomaly in the southern stream trapped off the SE Coast, but the polar jet doesn't begin to get involved until later in November so not many snow chances. I do think there is a good chance we'll see the Aleutian ridge try to amplify late in the month with the NAO declining towards zero, and that may set up a Nina-like December pattern that favors snow in the northern tier as Canada tries to get chilly.

[WXeastern]

In the Northeast the weather pattern is taking a break after a wild period. The -NAO had to turn + for a period of time. Late November and early December will be a time to watch. If the NAO turns negative again then I think we are in for a wild winter. Looking at the forecast for 240 hours the models are hinting at a possible Nor-easter although at this point it does look like a rain storm. It is way too early to predict the winter period, especially after we just had a possible failure of an El Nino.

Yeah this pre frontal warming will be a short break from the -NAO but the next couple of strong lakes cutters should drive heights to build in close to the NAO region near thanksgiving. Im expecting a nice cold winter system around this timeframe!

Here is how the AO behaved this time of year in 2009

And here is how it is behaving this fall headed into met winter

The similarities are definately there...Oct 0f 2009 averaged -1.54..and Oct of 2012 averaged out to -1.51 IMO the odds of having something simialr to 09/10 is certainly on the table!

[nzucker]

Yeah this pre frontal warming will be a short break from the -NAO but the next couple of strong lakes cutters should drive heights to build in close to the NAO region near thanksgiving. Im expecting a nice cold winter system around this timeframe!

The similarities are definately there...Oct 0f 2009 averaged -1.54..and Oct of 2012 averaged out to -1.51 IMO the odds of having something simialr to 09/10 is certainly on the table!

I agree...November 2009 was largely dominated by a GoA low, but by late November heights were starting to build over Alaska, and a large blocking regime took hold starting in early December, basically a continuation of the October 2009 blocking which led to the 10/14 and 10/16 interior Northeast snowfalls. This year, we saw heavy blocking throughout most of October, culminating in the Nov 7th snowstorm after an historic cold snap, NYC's coldest start to November since the 1870s. We'll see a relaxation in the pattern now (with a weakness off the Southeast/Mid-Atlantic coast keeping temperatures near normal, unlike November 2009 which was an unmitigated torch), but then fun may begin after Thanksgiving.

It looks to me that the development of the Aleutian ridge mid-month eventually leads to a severely negative AO. The 0z GEFS show this really nicely. At 144, we have a strong Aleutian/Kamchatka block but the EPO/AO/NAO still look to be largely positive:

By 360 hours, the Aleutian ridge has amplified into a full blown -AO, and you are starting to see the "poles of cold" in the mid-latitudes such as the Eastern US, Europe, Central Asia, and Southern Alaska/Pacific Northwest: