January 2011 Thoughts: Area of Warmth Could Be Somewhat Limited

[Harry]

I didn't add 1966-67 to the list, because the ENSO Region 3.4 anomaly was > -0.5 throughout the winter.

Has a great QBO match ( the best by far ) and the AO and PDO was a bit negative but that is about it as far as 66-67 goes.

However a stronger case *could* be made for it if we see a bomb ( ala jan 67 ) in this region later in January.

But seriously. Good discussion Don and others. I am still kicking myself in the behind for not going colder this winter when everything i look at showed it.

[donsutherland1]

If one examines data consistent with the forecast teleconnection indices centered around 1/10/2011 for past January La Niña cases with an ENSO Region 3.4 anomaly of -1 or below and also examines the 12/29/2010 0z GFS ensemble means forecast for 312 hours, one finds:

GFS ensemble 500 mb height anomalies: 312 hours

GFS ensemble 850 mb temperature anomalies: 312 hours

Composite 500 mb Height Anomalies: January Cases:

Composite Temperature Anomalies: January Cases:

If one then rolls the January cases forward 10 days, one finds:

Composite 500 mb Height Anomalies: January Cases:

Composite Temperature Anomalies: January Cases:

The 10-day temperature anomalies look strikingly similar to the temperature anomalies for all the La Niña cases cited at the beginning of this thread (excluding 1985) when the AO averaged -0.1 or below for January:

In sum, at least for now, there seems to be some support for the kind of monthly temperature departures that have occurred during past La Niña events in January with an ENSO Region 3.4 anomaly of -1 or below and an average monthly AO of -0.1 or below.

[Ottawa Blizzard]

If one examines data consistent with the forecast teleconnection indices centered around 1/10/2011 for past January La Niña cases with an ENSO Region 3.4 anomaly of -1 or below and also examines the 12/29/2010 0z GFS ensemble means forecast for 312 hours, one finds:

GFS ensemble 500 mb height anomalies: 312 hours

GFS ensemble 850 mb temperature anomalies: 312 hours

Composite 500 mb Height Anomalies: January Cases:

Composite Temperature Anomalies: January Cases:

If one then rolls the January cases forward 10 days, one finds:

Composite 500 mb Height Anomalies: January Cases:

Composite Temperature Anomalies: January Cases:

The 10-day temperature anomalies look strikingly similar to the temperature anomalies for all the La Niña cases cited at the beginning of this thread (excluding 1985) when the AO averaged -0.1 or below for January:

In sum, at least for now, there seems to be some support for the kind of monthly temperature departures that have occurred during past La Niña events in January with an ENSO Region 3.4 anomaly of -1 or below and an average monthly AO of -0.1 or below.

Interesting! Each of those Januaries saw some very cold temperatures in my region. January 1917 and 1971 were also quite snowy

[Roger Smith]

The second last map looks like a polar bear being chased by a smart car.

Whatever that portends, I would expect some further periods of extreme cold to develop in eastern North America this winter. This isn't a very fancy scientific explanation, but there basically isn't much of a source for mild air in either the Gulf region or the Pacific, and the gates seem open for Siberian air to build across into the NWT and move southeast several more times. The main question will be, does this cold pattern get interactive with a storm track near the east coast, or will it become a quiet cold with the storm track weak and well off shore. I think it may get stormy too -- there are some fairly strong energy peaks at intervals of about seven days from now on. Would be watching the period Jan 17-20 for major developments.

[donsutherland1]

The GFS ensemble mean 500 mb and 850 mb figures for 1/10 remain remarkably consistent since I last posted them 2 days ago (Message #32):

500 mb height anomalies:

850 mb temperature anomalies:

Moreover, taking the objective analogs that are within 1 day or less of each other from the GFS and Canadian ensembles, one gets the following 500 mb map centered around 1/10:

All in all, the upper air pattern continues to evolve in a fashion that I believe will lead to a more limited than usual area of warm anomalies for January during a moderate/strong La Niña.

[Ji]

wow..cfs beat the euro monthlies?

[Snow Wizard]

Later in Feb and especially March is when analogs like 1892-93 and 1955-56 could come into play....

I would love to see an 1892-93 repeat. The NW got POUNDED that winter in late Jan / early Feb.

[uncle W]

I would love to see an 1892-93 repeat. The NW got POUNDED that winter in late Jan / early Feb.

we are a head of 1892-93 around NYC...January 1893 was one of the coldest on record...

snowfalls in 1892-93 for NYC...

2.3" 11/9

4.0" 11/29-30

1.5" 12/12

1.3" 12/20

0.1" 12/23

0.1" 12/25

6.0" 1/5-6

1.0" 1/9-10

5.0" 1/12........highs in the teens...

3.5" 14-15.....highs in the teens...

0.5" 1/30

0.5" 2/1

3.5" 2/13

9.2" 2/17-19

2.0" 2/22

0.3" 2/25

2.0" 2/28

6.0" 3/4

0.1" 3/7

0.5" 4/7

48.4" total

[Snow Wizard]

From someone who lives in the Pacific NW-this winter has NOT turned out to be cooler than normal...yet. The big -AO is not helping matters here at all. So we shall see what happens. January still is yet to come but my expectations for a "record" winter have been greatly diminished. I must say...we have had tremendous amounts of precip in western WA so that part of La Nina has met expectations. Not so sure of the "cooler" party anymore.

Still looks pretty good for all of you the the northeast though.

We have already had two periods with snow and low temps below 20 in the Western lowlands. Sitting at 21 degrees at my house right now. Not exactly a flop so far, especially when you consider it has always been expected Jan - Mar would be our best time. I hear you about the overall torchy pattern though.

[Snow Wizard]

we are a head of 1892-93 around NYC...January 1893 was one of the coldest on record...

snowfalls in 1892-93 for NYC...

2.3" 11/9

4.0" 11/29-30

1.5" 12/12

1.3" 12/20

0.1" 12/23

0.1" 12/25

6.0" 1/5-6

1.0" 1/9-10

5.0" 1/12........highs in the teens...

3.5" 14-15.....highs in the teens...

0.5" 1/30

0.5" 2/1

3.5" 2/13

9.2" 2/17-19

2.0" 2/22

0.3" 2/25

2.0" 2/28

6.0" 3/4

0.1" 3/7

0.5" 4/7

48.4" total

This goes to show both the NE and NW can get hit big time in the same winter. Seattle had 45 inches of snow between Jan 27 and Feb 8 and a total of 58 inches for the winter. This is showing signs it could be a great winter for both places again. Maybe we will see more winters where everyone can smile now.

[donsutherland1]

IMO, it is too soon to write the obituary for Winter 2010-11 in the Pacific Northwest. Indeed, from RaleighWx's model/ensemble webpage, one finds the following 1-5-day, 6-10-day, and 11-15-day 850 mb temperature anomalies forecast by the 12/31/2010 12z GFS ensembles.

1-5-day 850 mb temperature anomalies:

6-10-day 850 mb temperature anomalies:

11-15-day 850 mb temperature anomalies:

If one examines the ENSO-Teleconnection Indice matches I posted in Message #32 in this thread, one finds the following for the 11-15-day period:

In sum, at least from this vantage point, the GFS ensembles are now pointing to a sustained period of normal to sometimes below normal readings for the Pacific Northwest. At the same time, historic ENSO-Teleconnection Index matches also lend support to the idea on the GFS ensembles. Finally, I suspect that the most notable part of Winter 2010-11 for the Pacific Northwest will likely occur in the second half of the January. There should be the opportunity for snow and also cold readings, with a possible Arctic outbreak if some of the past La Niña cases are relevant.

[Snow Wizard]

IMO, it is too soon to write the obituary for Winter 2010-11 in the Pacific Northwest. Indeed, from RaleighWx's model/ensemble webpage, one finds the following 1-5-day, 6-10-day, and 11-15-day 850 mb temperature anomalies forecast by the 12/31/2010 12z GFS ensembles.

In sum, at least from this vantage point, the GFS ensembles are now pointing to a sustained period of normal to sometimes below normal readings for the Pacific Northwest. At the same time, historic ENSO-Teleconnection Index matches also lend support to the idea on the GFS ensembles. Finally, I suspect that the most notable part of Winter 2010-11 for the Pacific Northwest will likely occur in the second half of the January. There should be the opportunity for snow and also cold readings, with a possible Arctic outbreak if some of the past La Niña cases are relevant.

Beginning to look promising alright.

EDIT: The 12z Euro appears to be coming on board for a nice Western cold snap. Things are finally starting to look up for us!

[Snow Wizard]

The 0z GFS shows an historic snowstorm for Seattle. How amazing would that be after what just happened on the East Coast?

[VAwxman]

The 0z GFS shows an historic snowstorm for Seattle. How amazing would that be after what just happened on the East Coast?

Looking likely that you are going to get rocked by cold. Climate signals and modeling are in support. Too early to tell about snow yet but I imagine you will have chances for that as well. The West is just going to get hammered by cold once we rebuild the western Canada cold source, and this time it will be stronger easily than it has been all winter to date.

[Roger Smith]

Anyone with an ounce of sense would book three weeks vacation in a warm climate if they were living in western Canada and looked at the recent GFS runs.

It is going to be record breaking cold right out to the west coast looking at those charts, and easily -45 to -50 at times in the prairies, and likely to be -40 or lower in the Dakotas eventually too. This is some serious cold and it has to suggest a high potential for east coast snowstorms through mid to late January. Granted the pattern is not super amplified but would keep an eye on the periods around the 11th and 17th for east coast storm development.

[donsutherland1]

At 5 am, the temperature stood at 28°F (-2.2°C) in Seattle. From the 6z GFS' New Year's Day grab bag:

- A possible long-duration snowfall beginning around 168 hours

- A possible outbreak of severe cold with the forecast 2 meter temperature falling to 12°F (-11.3°C)

- Numerous days between now and then with low temperatures < 32°F (0°C)

In short, even as exact details may differ, the larger idea is that winter likely has not forgotten the Pacific Northwest.

As for Ottawa, which still has not seen a -20°C (-4°F) day this winter, the 6z GFS is the first run of that model to show such cold. At 360 hours--almost an eternity--it shows a 2 meter low of -24°C (-11°F). Again, exact details may well differ, but with the EPO forecast to go negative, truly cold air should at least bleed into our side of the globe and then be available across Canada to be tapped.

Happy New Year to all.

[Ottawa Blizzard]

At 5 am, the temperature stood at 28°F (-2.2°C) in Seattle. From the 6z GFS' New Year's Day grab bag:

- A possible long-duration snowfall beginning around 168 hours

- A possible outbreak of severe cold with the forecast 2 meter temperature falling to 12°F (-11.3°C)

- Numerous days between now and then with low temperatures < 32°F (0°C)

In short, even as exact details may differ, the larger idea is that winter likely has not forgotten the Pacific Northwest.

As for Ottawa, which still has not seen a -20°C (-4°F) day this winter, the 6z GFS is the first run of that model to show such cold. At 360 hours--almost an eternity--it shows a 2 meter low of -24°C (-11°F). Again, exact details may well differ, but with the EPO forecast to go negative, truly cold air should at least bleed into our side of the globe and then be available across Canada to be tapped.

Happy New Year to all.

Good to hear Don. January is starting to look a bit more promising. Environment Canada and The Weather Network are both calling for snow on Wednesday and Thursday, which should help replenish the snow which has been eaten up by this mild spell. You have to admit, this is starting to look a bit like the winters of 1957-58 and 1964-65. Our New Years has been very mild, just like New Years 1965/66.

[Roger Smith]

Yep, I was thinking of New Years Eve 1965 too, as a teenager I was visiting relatives in New Jersey and as a weather nut (thank God there was no internet) it made quite an impression on me coming from Ontario when the temperature soared into the high 60s and there was even a thunderstorm during the night. Back home it also reached 58 F (early signs of being a weather nut, I got a friend to read the station while away for the holiday).

The difference was that December 1965 was generally a very mild month unlike this past December. But the weather certainly turned in January 1966, although it did stay rather mild for about a week before much colder air started to arrive. There was quite a heavy snowstorm in Toronto on Jan 23-24, I recall measuring 16 inches of snow at my home weather station outside the city.

All I recall of the major east coast storm at the end of the month was a windy day with snow flurries. And that was pretty much the whole winter, because Feb 1966 was a very bland month and March turned quite mild.

[NJwinter23]

Just a general question here. There have been at least 2 persistent blocking features that ive noticed popping up this season, one obviously being the NAO, but the Aleutians block has also been very persistent. Is the forcing behind this ridge from La Nina?

[Mallow]

Just a general question here. There have been at least 2 persistent blocking features that ive noticed popping up this season, one obviously being the NAO, but the Aleutians block has also been very persistent. Is the forcing behind this ridge from La Nina?

I think so, personally.

I think the main reason we haven't seen the infamous "southeast ridge" is exactly because of that NAO block. Without that block, the Nina would take on more of a classic Aleutian/Southeast ridge look.

That southeast ridge will probably develop in earnest by February, but until then, the entire US could get in on the cold at times.

[Roger Smith]

I think the Alaska blocking is building due to retrograde height transfer from the Greenland blocking. This has been evident since mid-December with very high pressures at times in the central Canadian arctic. I would look for the explanation in angular momentum transfer from external sources such as interactions between magnetosphere and solar system magnetic field sectors. This theory predicted the blocking and suggests that it should remain strong through January and break down in February with a rapid evolution to more zonal flow over western North America and a mean upper ridge over the Rockies at that stage.

Expect one of those winters where January is -5 to -10 across much of the central and western regions and February is +3 to +6 with the center of the cold anomaly shifting to about Quebec and New England in February.

The role of La Nina in this would be marginal because the background signal contains only perhaps 10% of the variance of the blocking phase and the later mild phase if that verifies.

[Mallow]

I think the Alaska blocking is building due to retrograde height transfer from the Greenland blocking. This has been evident since mid-December with very high pressures at times in the central Canadian arctic. I would look for the explanation in angular momentum transfer from external sources such as interactions between magnetosphere and solar system magnetic field sectors. This theory predicted the blocking and suggests that it should remain strong through January and break down in February with a rapid evolution to more zonal flow over western North America and a mean upper ridge over the Rockies at that stage.

Expect one of those winters where January is -5 to -10 across much of the central and western regions and February is +3 to +6 with the center of the cold anomaly shifting to about Quebec and New England in February.

The role of La Nina in this would be marginal because the background signal contains only perhaps 10% of the variance of the blocking phase and the later mild phase if that verifies.

The full-latitude blocks can't really be explained simply by retrogression of Greenland blocking. The high heights at the high latitudes, perhaps, but you need a sort of phasing of the southern ridge to get a full-latitude block, and it's that southern ridge whose source is likely tied back to La Nina forcing, in large part.

[Nikolai]

I think so, personally.

I think the main reason we haven't seen the infamous "southeast ridge" is exactly because of that NAO block. Without that block, the Nina would take on more of a classic Aleutian/Southeast ridge look.

That southeast ridge will probably develop in earnest by February, but until then, the entire US could get in on the cold at times.

I went for a warm February in my winter outlook, but I'm beginning to have my doubts. If blocking continues to persist--and why shouldn't it, given it has for the past year and more--then February could very well lack a dominating SE ridge. In my outlook I originally thought we would flip to warm after mid-January but that's probably not going to happen. Perhaps we see a pattern reload once more around February 1st, just like what happened initially in early December and again right now?

[NJwinter23]

I think so, personally.

I think the main reason we haven't seen the infamous "southeast ridge" is exactly because of that NAO block. Without that block, the Nina would take on more of a classic Aleutian/Southeast ridge look.

That southeast ridge will probably develop in earnest by February, but until then, the entire US could get in on the cold at times.

Thanks Mallow. This is what I've been believing/assuming as well, but I realized that it couldn't hurt to ask the educated ones on here for a real explanation.

[eduggs]

I really like this post. I appreciate a statistical/analytical/numerical approach to forecasting. But a few thoughts:

The correlation between reconstructed NAO and AO is very weak (r squared ~ 0.1). The sample size is also small. And how reliable are the NAO reconstructions? From a statistical standpoint I would assign low confidence to this forecast. In fact a forecast based purely on a conceptual pattern or basic persistence might have more viability. I love your methods however. And maybe I am misinterpreting the statistical data you provided.

[am19psu]

I really like this post. I appreciate a statistical/analytical/numerical approach to forecasting. But a few thoughts:

The correlation between reconstructed NAO and AO is very weak (r squared ~ 0.1). The sample size is also small. And how reliable are the NAO reconstructions? From a statistical standpoint I would assign low confidence to this forecast. In fact a forecast based purely on a conceptual pattern or basic persistence might have more viability. I love your methods however. And maybe I am misinterpreting the statistical data you provided.

There are multiple papers about the Northern Annular Mode out there that show this is not true for the cold season. The correlation is closer to .7 or .8 during the winter months.

[eduggs]

There are multiple papers about the Northern Annular Mode out there that show this is not true for the cold season. The correlation is closer to .7 or .8 during the winter months.

That actually makes a lot of physical sense to me. And it would significantly strengthen any statistical conclusions based on this correlation if a more targeted data set were used. I was just referring to the figure Don provided in his original post.

[donsutherland1]

Several quick points to hopefully clarify things:

1. For the data I posted, the coefficient of determination was: 0.333 and the coefficient correlation was 0.577. That sample used monthly data comparing the reconstructed NAO vs. the AO. Those figures, while not great, are far from indicative of a near meaningless relationship. Unfortunately, neither the AO nor NAO were regularly recorded regularly prior to 1950. The NAO has been reconstructed from a variety of sources. It is an educated guess as to what it might have been.

2. When the AO and NAO are restricted to December-February, the coefficient of determination is 0.551 and the coefficient of correlation is 0.742.

3. The historic data from the reconstuctions was only one part of a larger argument. Ensemble data and ENSO-Teleconnection Index data were also used.

Everything together, not just the piece that relies on reconstructed data, presents a reasonable case that January could well see a more limited area of warm anomalies than is typical during moderate/strong La Niña events. The reconstructed data only hints that there may be some past precedent for the kind of pattern I expect to prevail given general blockiness. Certainly, even if one casts aside the reconstructed data, one could still point to such La Niña events as 1916-17 to note that there were past events that deviated from the more recent experience with moderate/strong La Niñas.

In the end, once January comes to a close, we'll see how things verified.

[am19psu]

Several quick points to hopefully clarify things:

1. For the data I posted, the coefficient of determination was: 0.333 and the coefficient correlation was 0.577. That sample used monthly data comparing the reconstructed NAO vs. the AO. Those figures, while not great, are far from indicative of a near meaningless relationship. Unfortunately, neither the AO nor NAO were regularly recorded regularly prior to 1950. The NAO has been reconstructed from a variety of sources. It is an educated guess as to what it might have been.

2. When the AO and NAO are restricted to December-February, the coefficient of determination is 0.551 and the coefficient of correlation is 0.742.

3. The historic data from the reconstuctions was only one part of a larger argument. Ensemble data and ENSO-Teleconnection Index data were also used.

Everything together, not just the piece that relies on reconstructed data, presents a reasonable case that January could well see a more limited area of warm anomalies than is typical during moderate/strong La Niña events. The reconstructed data only hints that there may be some past precedent for the kind of pattern I expect to prevail given general blockiness. Certainly, even if one casts aside the reconstructed data, one could still point to such La Niña events as 1916-17 to note that there were past events that deviated from the more recent experience with moderate/strong La Niñas.

In the end, once January comes to a close, we'll see how things verified.

Thanks for clarifying that, Don. Again, excellent analysis, as always.

[okie333]

Several quick points to hopefully clarify things:

1. For the data I posted, the coefficient of determination was: 0.333 and the coefficient correlation was 0.577. That sample used monthly data comparing the reconstructed NAO vs. the AO. Those figures, while not great, are far from indicative of a near meaningless relationship. Unfortunately, neither the AO nor NAO were regularly recorded regularly prior to 1950. The NAO has been reconstructed from a variety of sources. It is an educated guess as to what it might have been.

2. When the AO and NAO are restricted to December-February, the coefficient of determination is 0.551 and the coefficient of correlation is 0.742.

3. The historic data from the reconstuctions was only one part of a larger argument. Ensemble data and ENSO-Teleconnection Index data were also used.

Everything together, not just the piece that relies on reconstructed data, presents a reasonable case that January could well see a more limited area of warm anomalies than is typical during moderate/strong La Niña events. The reconstructed data only hints that there may be some past precedent for the kind of pattern I expect to prevail given general blockiness. Certainly, even if one casts aside the reconstructed data, one could still point to such La Niña events as 1916-17 to note that there were past events that deviated from the more recent experience with moderate/strong La Niñas.

In the end, once January comes to a close, we'll see how things verified.

To find out that 1916-17 was a La Niña, you need reconstructed data. Hence the impossibility of casting reconstructed data totally aside.