AO Forecast to Plunge

[PhineasC]

I'm not liking the looks of the longer range models. Looks like the blocking breaks down without the West ever getting a chance at something good. I'm more than a little bit worried about a bust.

You guys never cash in on the big Ninas.

[BlizzardWx]

You guys never cash in on the big Ninas.

Whenever people say "never" I feel the need to call them on it if its false. Never is false. Think, for example 88/89 or 49/50 for starters. Its not common but not uncommon either.

[JBG]

Whenever people say "never" I feel the need to call them on it if its false. Never is false. Think, for example 88/89 or 49/50 for starters. Its not common but not uncommon either.

Did Toronto and Montreal/Ottawa cash in on 1988/89 and 1949/50? And is there a good database with historical figures for Canadian cities? Wunderground only goes back to 1996 for those cities, I believe. (Edited to reflect that now it goes back further, but still any good databases?).

[Organizing Low]

Did Toronto and Montreal/Ottawa cash in on 1988/89 and 1949/50? And is there a good database with historical figures for Canadian cities? Wunderground only goes back to 1996 for those cities, I believe. (Edited to reflect that now it goes back further, but still any good databases?).

http://www.climate.w.../Welcome_e.html

click on 'climate data online' link

[Ottawa Blizzard]

http://www.climate.w.../Welcome_e.html

click on 'climate data online' link

This is the best database on the web, hands down.

I949/50 was an odd winter up here. Mild spell in January (one of the warmest january temperatures ever recorded up here- 61F!) but February 1950 was a good month, with snow and temperatures down to -30 celcius.

1988-89 was a bust. There was a cold spell in December 1988, but it was also the first green Christmas ever recorded at Montreal's airport. There was a bitter cold spell in early january 1989. I remember getting a new sled for Christmas that year and being sad at not being able to try it out; there was no snow on the local hill that Christmas season. I lived in Toronto at the time.

Interestingly, I find there to be many similarities between this year and that year. Summer 1988 was very hot, just like this one was. In fact, a major heatwave occurred around the same time in July 1988 as in July 2010. We have a strong La Nina, like that year.

[tacoman25]

You guys never cash in on the big Ninas.

The last time we saw a Nina this powerful (looking at MEI/ONI combined) was 1988-89. The PNW did very well Feb/Mar that winter.

1955-56 and 1949-50 were both also strong Ninas, and the PNW had excellent winters both years.

They have already seen their third greatest Nov Arctic outbreak on record this winter... 25/14 at Seattle prior to Thanksgiving is pretty damn impressive.

[Ottawa Blizzard]

Joe Bastradi seems to think that the cold this month will be centred from the upper midwest down through Chicago through to the mid atlantic and southeast. Buffalo, Detroit and Toronto are in the -3F zone, while Ottawa is just on normal.

He's also hinting at a big flip similar to 1990 and 2006. He's not saying it will happen, but that it's on the table. Of the two, I'd prefer 2006 as that January saw more snow - Quebec City saw incredible amounts of snow that year as the storm track lifted way north. The funny thing is that for a flip to be noticed, one has to have winter first. December 1989 was extremely cold and thus the flip was very noticable up here. However, such may not be the case this year!

[JBG]

I949/50 was an odd winter up here. Mild spell in January (one of the warmest january temperatures ever recorded up here- 61F!) but February 1950 was a good month, with snow and temperatures down to -30 celcius.

1988-89 was a bust. There was a cold spell in December 1988, but it was also the first green Christmas ever recorded at Montreal's airport. There was a bitter cold spell in early january 1989. I remember getting a new sled for Christmas that year and being sad at not being able to try it out; there was no snow on the local hill that Christmas season. I lived in Toronto at the time.

Interestingly, I find there to be many similarities between this year and that year. Summer 1988 was very hot, just like this one was. In fact, a major heatwave occurred around the same time in July 1988 as in July 2010. We have a strong La Nina, like that year.

Would the fact that 1988-9 occurred during a long-term +PDO phase have explained the difference bewteen that Niña and 1949-50?

[PAblizzardlover]

never bet against Don.

Except when it comes to last March! lol

[A-L-E-X]

This is the best database on the web, hands down.

I949/50 was an odd winter up here. Mild spell in January (one of the warmest january temperatures ever recorded up here- 61F!) but February 1950 was a good month, with snow and temperatures down to -30 celcius.

1988-89 was a bust. There was a cold spell in December 1988, but it was also the first green Christmas ever recorded at Montreal's airport. There was a bitter cold spell in early january 1989. I remember getting a new sled for Christmas that year and being sad at not being able to try it out; there was no snow on the local hill that Christmas season. I lived in Toronto at the time.

Interestingly, I find there to be many similarities between this year and that year. Summer 1988 was very hot, just like this one was. In fact, a major heatwave occurred around the same time in July 1988 as in July 2010. We have a strong La Nina, like that year.

Actually with how dry it was and the type of heat we had-- it was a lot like 1955 and 1966-- with a dash of 1999 thrown in..  Notice the 11 year cycle lol.  

[Snow Wizard]

You guys never cash in on the big Ninas.

The last I looked big Ninas are usually really bad for the East Coast. Obviously the rules are changed this year.

[RIC Airport]

The last I looked big Ninas Ninos are usually really bad for the East Coast. Obviously the rules are changed this year.

fixed.......i could've sworn I heard the same about last year.

[A-L-E-X]

fixed.......i could've sworn I heard the same about last year.

Well, whenever you see someone say "always" or "never" you know it cant be right lol.  It depends a lot on latitude.  Usually the NAO can bail us out in either case as long as it stays negative, regardless of ENSO.  And we're right in the middle of a longterm neg nao cycle-- no one can dispute that anymore. 

[Chris L]

fixed.......i could've sworn I heard the same about last year.

We can thank the super strong block for that..

[RIC Airport]

Well, whenever you see someone say "always" or "never" you know it cant be right lol. It depends a lot on latitude. Usually the NAO can bail us out in either case as long as it stays negative, regardless of ENSO. And we're right in the middle of a longterm neg nao cycle-- no one can dispute that anymore.

We can thank the super strong block for that..

I know, but people are still tryna sell their typical Nina outlooks for JAN/FEB despite the magnitude of blocking we've been seeing and are likely to see again later in the winter.

[Jebman]

12z GFS shows a 1080mb High over Greenland:

Incredible strong high. I didn't even know you could get 1080 mb highs!!

I am LOVIN' this negative NAO and AO so much!!!!!

I have been savoring so many enjoyable jebwalks in the fresh cold air that I love from the bottom of my weenie heart!!!!!

IF ONLY I had some snow to run in, passionately kicking up powdery white plumes of snow as I celebrate an EPIC cold outbreak!!!!!

WOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO-------HOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!

Bring It ON!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Quakertown needs snow]

Thanks for this post Don.

[donsutherland1]

This is the best database on the web, hands down.

I strongly agree. I really like how Environment Canada makes all of the data for the Canadian cities available to as far back as the record goes. EC's online database is an invaluable resource.

[donsutherland1]

IF ONLY I had some snow to run in, passionately kicking up powdery white plumes of snow as I celebrate an EPIC cold outbreak!!!!!

My guess is that you will have some snow opportunities. I suspect that much of the East Coast will be sideswiped by a developing system this weekend and it could possibly throw a few inches back into the big cities from Virginia to southern New England. That's not yet assured, but I believe it is a reasonable possibility at this time.

[Scarlet Pimpernel]

To date, some of the major cities of the Middle Atlantic and New England regions have witnessed almost no snowfall. A few flurries have fallen, but that is about it. Select data seasonal data through 12/10:

Boston: Trace

New York City: Trace

Philadelphia: Trace

Washington, DC: Trace

However, the next 2-3 weeks should see accumulating snow in most or all of those cities. Almost in a replay of December 2009, the AO is forecast to fall to extremely negative levels just after midmonth and then remain generally negative for some time to come. If past extreme blocks are representative, the forecast block should last into at least the first week in January.

The GFS ensembles show the AO bottoming out in the -6 to -4 range.

If the AO falls to -4 or below, that will be the first time on record that it has fallen to such an extreme level when the ENSO Region 3.4 anomaly was -1.00°C or below. However, it has fallen to such levels during three La Niñas with December ENSO Region 3.4 values of -0.80°C or colder: 1950, 1995, and 2000. During Winter 1950-51, about a third of the Northeast’s and Mid-Atlantic’s seasonal snowfall occurred around the time of the extreme blocking. The extreme 1995 and 2000 blocks each saw a KU snowstorm.

Since 1950 when monthly ENSO data has been available on a regular basis, there has been no KU snowstorm when the ENSO Region 3.4 anomaly was -1.00°C or below. Hence, odds are probably against such a snowstorm during the possible extreme December 2010 block, but if the small sample has meaning (and the larger sample of extreme blocks supports the tiny La Niña sample), there should be some accumulating snow and perhaps a moderate snowstorm over the next 2-3 weeks.

Hey Don, good to see you again this year...and thanks for the update! Appreciated your discussions and insights last winter as well. With luck, perhaps we won't have the "stereotypical" La Nina winter, a'la nothing but cold/dry...warmer/rain...cold/dry. Though I would be somewhat concerned about it being a very dry winter going into next spring and summer. As I've heard others say (here and elsewhere), the AO/NAO may well play the role of the wild card this year. One good setup at the right time even for just one good event (or great event) pretty well makes the entire winter in these parts.

[JBG]

I know, but people are still tryna sell their typical Nina outlooks for JAN/FEB despite the magnitude of blocking we've been seeing and are likely to see again later in the winter.

Incredible strong high. I didn't even know you could get 1080 mb highs!!

I am LOVIN' this negative NAO and AO so much!!!!!

My understanding of La Niñas for the East Coast is they alternate between "wintry" phases,w hich are the phases with -NAO, and warm, dry phases, with +NAO. Plenty of such winters have featured significant, though not always below or above normal snow, such as 1955-6, 1970-1, 1973-4, 1988-9 (cold only, and in December, and little snow), and 1999-2000. All but 1970-1 were, on balance, warmer and dryer than normal when counting meteorological winter, either December 1 or 6 through either March 1 or 6. Parenthetically, I prefer using the 6th day of the month in order to embrace the coldest 90 day periods, and I have noticed that it is usually a few days into December when the balmy, periods break decisively.

[Snow Wizard]

I know, but people are still tryna sell their typical Nina outlooks for JAN/FEB despite the magnitude of blocking we've been seeing and are likely to see again later in the winter.

The trough will shift into the West eventually. That is by far the favored trough position in Nina of this strength.

[NaoPos]

The trough will shift into the West eventually. That is by far the favored trough position in Nina of this strength.

It was on the west coast by mid november, and the 2nd half of the month ended up below if im not mistaken.. -NAO

[HKY_WX]

The last I looked big Ninas are usually really bad for the East Coast. Obviously the rules are changed this year.

The 60's are probably the best snow years around here in history and the entire decade was mostly -PDO/la nina. ENSO is important, but this year should prove it's only one factor. NAO is just as important and seems to operate as a separate entity.

[Snow Wizard]

It was on the west coast by mid november, and the 2nd half of the month ended up below if im not mistaken.. -NAO

It seems that what happened here in November was a lucky break during a pattern that was in transition. I would certainly expect the West to have a trough lock in for a longer period sometime during the winter.

[nzucker]

It seems that what happened here in November was a lucky break during a pattern that was in transition. I would certainly expect the West to have a trough lock in for a longer period sometime during the winter.

Probably in February as we saw in 54-55 and 88-89.

[Harry]

Probably in February as we saw in 54-55 and 88-89.

FYI.. BOTH Dec 1954 and 1988 had a +NAO for the month of December. Also the AO was pretty well into the positive side in Dec 1988 at +1.679. Sorry but they are non analogs at this point especially 1988-89. Not really sure what is good at this point as this is pretty remarkable what we have and look to have as far as the AO/NAO go and Nina? Lastly as well it is about certain now that per the Tri Monthly method this Nina will never reach strong and or end up as strong as either of those did. May have it with the MEI but that is about it. The whole basin has been slowly but surely warming the past week or so and really picked up with the warming yesterday and today. per the daily stuff we are now at a weak nina in 3, 3.4, and 4. Regions 3 and 3.4 are at about -0.8 or so and region 4 is at -0.7 or so.

[jbcmh81]

I have a question and maybe someone can help me out.

I was looking just at my area at La Nina winters since 1900, particularly those that had a cold December. Currently most of the OV is 6-10 degrees below normal, and the cold looks to stick around at least towards the end of the month. If we can maintain these kinds of negative departures, it would be only the 5th La Nina to have such a cold December for us. The others were 1903-04, 1950-51, 1962-63, and 2000-01. Not a single one of these winters featured a blowtorch January. January 1951 was above normal, but barely, and the only other month out of these winters that was above normal was February 2001.

Given the extreme blocking going on and that may end up repeating later on, why is this particular winter set to go against history and switch so dramatically to a warm pattern? I know it's a small sample of just 4 winters, but even when I looked at the entire set of 28 La Ninas since 1900, December was still the coldest month in just 4 of them. 14 others had January as the coldest, and February was the coldest in the final 10.

Also, what set apart 1903-04 and 1962-63 that featured all three months being severely cold? What was the blocking situation then?

[Snow Wizard]

FYI.. BOTH Dec 1954 and 1988 had a +NAO for the month of December. Also the AO was pretty well into the positive side in Dec 1988 at +1.679. Sorry but they are non analogs at this point especially 1988-89. Not really sure what is good at this point as this is pretty remarkable what we have and look to have as far as the AO/NAO go and Nina? Lastly as well it is about certain now that per the Tri Monthly method this Nina will never reach strong and or end up as strong as either of those did. May have it with the MEI but that is about it. The whole basin has been slowly but surely warming the past week or so and really picked up with the warming yesterday and today. per the daily stuff we are now at a weak nina in 3, 3.4, and 4. Regions 3 and 3.4 are at about -0.8 or so and region 4 is at -0.7 or so.

Absolutely no way Nino 3.4 is weak now. It was -1.6 on the last weekly update. Such a rise would be beyond record setting. I think the MEI is the best measure of a Nina anyway. As for analogs 1950 is the only one that really fits at all.

[Snow Wizard]

I have a question and maybe someone can help me out.

I was looking just at my area at La Nina winters since 1900, particularly those that had a cold December. Currently most of the OV is 6-10 degrees below normal, and the cold looks to stick around at least towards the end of the month. If we can maintain these kinds of negative departures, it would be only the 5th La Nina to have such a cold December for us. The others were 1903-04, 1950-51, 1962-63, and 2000-01. Not a single one of these winters featured a blowtorch January. January 1951 was above normal, but barely, and the only other month out of these winters that was above normal was February 2001.

Given the extreme blocking going on and that may end up repeating later on, why is this particular winter set to go against history and switch so dramatically to a warm pattern? I know it's a small sample of just 4 winters, but even when I looked at the entire set of 28 La Ninas since 1900, December was still the coldest month in just 4 of them. 14 others had January as the coldest, and February was the coldest in the final 10.

Also, what set apart 1903-04 and 1962-63 that featured all three months being severely cold? What was the blocking situation then?

Truth be known, nobody can really say what this winter will do. It's too much of an oddball. Odd enough that they just had a serious tornado near Portland OR.

1962-63 was a cold winter just about everywhere. The entire northern US and western Europe both had a VERY cold January. The indices were all severely negative. The data back in 1903 isn't good enough to really know what happened there.