Medium Range Discussion Winter 2011-12

[Harry]

One can use pre-1950 analogs for SSTAs, ENSO, and ENSO-reconstructed data, among others. The ENSO-reconstructed NAO data proved useful last winter in highlighting a number of moderate-strong La Niña cases during which KU-type snowstorms occurred. Analogs from 1950-present are only possible for daily teleconnections data. The timeframe for daily MJO data is even more recent. Analogs offer insight. My view is that one should try to draw as broad and representative a sample as possible, keeping in mind the limitations inherent with analogs.

Nice post Don. I agree. Yeah they are far from the end all but i do think they add alot of value and should not be discarded either especially when newer ones ( after 1950 ) have glaring holes in them. Don't forget too we have solar stuff too that goes way back for those interested in that.

[Isotherm]

Note the day 10 and 14 GFS ensemble AO forecasts versus actual observations (black line) over the past month. In strong contrast to Dec/Jan, the AO has now been negative to much more negative than progged in the D 10-15 range. Even out at D7, there is a slight positive bias to GFS ensembles. What this may mean is the current proggs for a slightly positive AO in the D 10-15 time frame could bust on the high side. I wouldn't be surprised if the AO reaches or exceeds neutral, but then I'd expect it to generally stay neutral-slightly negative. The strat vortex has been pretty thoroughly destroyed, so I don't think we're looking at a mod/strongly positive AO any time soon at least.

[donsutherland1]

Some quick thoughts...

1. Another "snowstorm" (Winter 2011-12 style) is "raging." Wet snowflakes are falling but for the most part nothing is accumulating. In any case, although the "storm" might be a sorry spectacle for many, a light snow event is always better than no snow event. On this date back in 1983, an all-out blizzard was moving up the the East Coast.

2. The EPO is expected to remain positive through the extended period toward the closing days of February. Hence, no severe cold is likely anytime soon. With the AO forecast to go positive, no KU storms are likely either (La Niña-AO+ combinations are not conducive to such storms).

3. The coming cold shot will not be all that impressive. It probably won't even approach the mid-January cold shot in terms of readings.

4. With the La Niña remaining remarkably stable, prospects for expansive warmth in a part of North America are increasing. Rising analogs include 1974 and 1985. For now, it is too soon to be certain of the outcome, as the evolution of the La Niña will be critical. FWIW, the CFSv2 is somewhat 1985-esque in the CONUS and parts of Canada. It favors cold in the western quarter to third of North America and warmth eastward. Its primary difference from 1985 is its forecast for cold in Alaska.

[buckeye]

Some quick thoughts...

1. Another "snowstorm" (Winter 2011-12 style) is "raging." Wet snowflakes are falling but for the most part nothing is accumulating. In any case, although the "storm" might be a sorry spectacle for many, a light snow event is always better than no snow event. On this date back in 1983, an all-out blizzard was moving up the the East Coast.

2. The EPO is expected to remain positive through the extended period toward the closing days of February. Hence, no severe cold is likely anytime soon. With the AO forecast to go positive, no KU storms are likely either (La Niña-AO+ combinations are not conducive to such storms).

3. The coming cold shot will not be all that impressive. It probably won't even approach the mid-January cold shot in terms of readings.

4. With the La Niña remaining remarkably stable, prospects for expansive warmth in a part of North America are increasing. Rising analogs include 1974 and 1985. For now, it is too soon to be certain of the outcome, as the evolution of the La Niña will be critical. FWIW, the CFSv2 is somewhat 1985-esque in the CONUS and parts of Canada. It favors cold in the western quarter to third of North America and warmth eastward. Its primary difference from 1985 is its forecast for cold in Alaska.

great news Don! The faster we can kill off this miserable suffering winter and begin an unseasonably mild early start to spring the better.

Btw, your information throughout this season has been remarkably helpful and accurate.

[Feb]

great news Don! The faster we can kill off this miserable suffering winter and begin an unseasonably mild early start to spring the better.

Btw, your information throughout this season has been remarkably helpful and accurate.

His last two winters have been very good until mid February into March.

[donsutherland1]

great news Don! The faster we can kill off this miserable suffering winter and begin an unseasonably mild early start to spring the better.

Btw, your information throughout this season has been remarkably helpful and accurate.

Many thanks for the kind words, Buckeye.

[easternsnowman]

Looking at long range models which have not been reliable at all, does'nt mean that a forecast is set in stone.

[donsutherland1]

His last two winters have been very good until mid February into March.

That's correct. I've reviewed those bad late-winter/early-spring endings and have made some adjustments in how I weight possible analog cases. I suspect that the spring transition itself needed greater consideration. We'll see how things work out this time around.

[easternsnowman]

late winter is very hard to predicat and la nina's tend to be cool to cold through spring.

[donsutherland1]

late winter is very hard to predicat and la nina's tend to be cool to cold through spring.

Not all. There are numerous warm ones i.e., 1974, 1976, 1985, 2000, etc. The four aforementioned La Niñas were characterized by a lot of warmth in the East, both during March and the March-May period as a whole.

[QVectorman]

Don, since Ellinwood posted his EPO temp anomalies it looks like +EPO may be the driver here. Matches up pretty nicely to the map you posted yesterday.

[easternsnowman]

Not all. There are numerous warm ones i.e., 1974, 1976, 1985, 2000, etc. The four aforementioned La Niñas were characterized by a lot of warmth in the East, both during March and the March-May period as a whole.

I remember in 2000 I believe april 9 I had 4 inches of snow but that march was particularly warm that year. I believe in 76 there was a snowstorm in the 6-8 inch range mid march. I also believe there was some snow in 74 and 85 in march.

[easternsnowman]

Don, since Ellinwood posted his EPO temp anomalies it looks like +EPO may be the driver here. Matches up pretty nicely to the map you posted yesterday.

Of course other factors must come into play. In general if someone forecasts a couple above normal most likely they will be right, because that seems to be the new average.

[donsutherland1]

Of course other factors must come into play. In general if someone forecasts a couple above normal most likely they will be right, because that seems to be the new average.

A warming climate does not mean that natural variability cannot lead to colder than normal outcomes. The severe cold that is gripping Europe is an example. Climate concerns long-term baselines. Weather, including monthly and seasonal outcomes, is shorter-term in nature

[uncle W]

I remember in 2000 I believe april 9 I had 4 inches of snow but that march was particularly warm that year. I believe in 76 there was a snowstorm in the 6-8 inch range mid march. I also believe there was some snow in 74 and 85 in march.

there were a few wintry periods in April during the 1970's...In NYC record or near record cold was observed in 1972, 1974, 1975, 1976, 1977...the 1970's had snowstorms in March 1970, 1971, 1972, 1974, 1976, 1978, 1980...the years with near record cold in April had record warmth later in April or in May...

[donsutherland1]

I remember in 2000 I believe april 9 I had 4 inches of snow but that march was particularly warm that year. I believe in 76 there was a snowstorm in the 6-8 inch range mid march. I also believe there was some snow in 74 and 85 in march.

Warm periods can have shorter periods of colder, snowy weather embedded in them. One should not expect uniformity. April 1976 had an epic early spring heat wave. April 2000 saw temperatures rise into the lower 90s near the end of the month. Overall, Spring 1976 and Spring 2000 were warmer than normal across much of the East.

[Ottawa Blizzard]

A warming climate does not mean that natural variability cannot lead to colder than normal outcomes. The severe cold that is gripping Europe is an example. Climate concerns long-term baselines. Weather, including monthly and seasonal outcomes, is shorter-term in nature

Don, I'm going to guess that you are not in agreement with JB in thinking that this European cold wave is a prelude to a cooling climate?

[donsutherland1]

Don, I'm going to guess that you are not in agreement with JB in thinking that this European cold wave is a prelude to a cooling climate?

I don't agree with him. Substantial variation in regional temperatures, including strong cold anomalies, can result in the context of a warming global climate. The severe cold in Europe is mainly a product of the pattern that has prevailed. Below is a chart with the composite for all dates in the February 1-15, 1950-2011 timeframe vs. the cold anomalies that have occurred during the February 1-9, 2012 timeframe.

The cold this time around is somewhat more expansive and it is more severe. However, the Arctic this time around is much warmer than it has typically been during similar patterns. The Arctic has been drained of its cold air and that cold air is responsible for the severe cold in Europe.

[Snowstorms]

I don't agree with him. Substantial variation in regional temperatures, including strong cold anomalies, can result in the context of a warming global climate. The severe cold in Europe is mainly a product of the pattern that has prevailed. Below is a chart with the composite for all dates in the February 1-15, 1950-2011 timeframe vs. the cold anomalies that have occurred during the February 1-9, 2012 timeframe.

The cold this time around is somewhat more expansive and it is more severe. However, the Arctic this time around is much warmer than it has typically been during similar patterns. The Arctic has been drained of its cold air and that cold air is responsible for the severe cold in Europe.

To continue, this is having an negative impact on the Sea ice growth across the Kara Sea and Eastern Greenland since the blocking is centered across that region and the greatest warm anomalies for much of this Winter and Fall have been present across that region with near record high sea ice extent across the Bering in relation to the extreme AK vortex and/or consistent PV.

I dont think climate change (if there really is one currently) is a playing a role in the extreme variations of temps/precip this Winter across the Northern Hemisphere. There are many things on the table that are responsible for the "non-winter" across North America and what were seeing is not unusual as its been observed before. Climate tends to repeat itself so lets see.

The unusually strong Pacific jet in relation to the MJO and the AK Vortex allowed mild pacific air to dominate across much of North America and despite the AO going negative in January, it was centered too far north thus it couldnt really put a dent in those warm anomalies coupled with the dead MJO wave. I analyzed a couple of variables Don, and I found something really interesting centered for April only. I decided to look at most of the warm La Nina Winters since 1950 and I centered those analgoues for April. The analogues suggest a colder than normal April across much of the board but these same analogues yield a much warmer conclusion for May across the East.

Now this analysis is just based on temperature trends across North America. Once we get closer I will analyze other factors such as the MJO, PDO, AO, etc.

[toronto blizzard]

I'm with you snowstorms I think this whole climate change business is silly to say the least I mean cmon the arctic was melting in the 1920s but you don't dare here that today. And I agrre with you on how this mild winter is caused by the natural factors like the EPO and NAO etc and not Global Warming.

[donsutherland1]

I dont think climate change (if there really is one currently) is a playing a role in the extreme variations of temps/precip this Winter across the Northern Hemisphere. There are many things on the table that are responsible for the "non-winter" across North America and what were seeing is not unusual as its been observed before.

The following posted message in the climate change forum offers my view concerning the variability seen in Winter 2011-12 (excessive North America warmth, severe cold in Europe, etc.) and where the impact of climate change can perhaps be seen: http://www.americanw...ost__p__1329666. A full discussion of the possible role of climate change is beyond the scope of this thread. Therefore, I provided the above link.

[easternsnowman]

Warm periods can have shorter periods of colder, snowy weather embedded in them. One should not expect uniformity. April 1976 had an epic early spring heat wave. April 2000 saw temperatures rise into the lower 90s near the end of the month. Overall, Spring 1976 and Spring 2000 were warmer than normal across much of the East.

I just don't see us having too warm a spring, in fact I'm thinking March will be colder than normal and more snowy also.......using the 1956 analalog.

[Logan11]

2011 11 .51 0.92

2010 1 (tie) 0.64 1.15

2009 7 (tie) 0.58 1.04

2008 13 0.50 0.90

2007 7 (tie) 0.58 1.04

2006 6 0.59 1.06

2005 1 (tie) 0.64 1.15

2004 9 0.56 1.01

2003 4 0.61 1.10

2002 5 0.60 1.08

2001 10 0.54

Year, Rank, Amount above 20th century average global temperature in C and F

2001-2005 + .590

2006-2010 + .578

It's hard to see a clear warming trend so far in this century. It seems more like a plateau to me. You can say 2011 was cooler partly because of the La Nina I suppose. Things better start to warm consistently again in the second decade of the century or the whole global warming theory may collapse.

I'm with you snowstorms I think this whole climate change business is silly to say the least I mean cmon the arctic was melting in the 1920s but you don't dare here that today. And I agrre with you on how this mild winter is caused by the natural factors like the EPO and NAO etc and not Global Warming.

[donsutherland1]

February 23-29, 2012 Thoughts...

With temperatures in the teens in parts of New England and 20s in the Mid-Atlantic, it feels wintry today. However, just as had been the case time and again during this winter, the period of cold is likely to be brief. Down the road, the closing week of February looks to close perhaps pretty much as the month began: warm across much of North America and cold across large parts of Europe.

The composite temperature anomalies based on ENSO Region 3.4 anomalies of -1.55°C to -0.70°C, an AO of 0.00 to +1.50, and a PNA of -1.00 to 0.00 for the 2/20-29/1950-2011 timeframe for North America and Europe are below:

With the CPC site not updating the spread of the GFS ensemble members for the teleconnections, there is greater uncertainty than usual. For North America, a larger portion of the Pacific Northwest could wind up cooler than shown on the composite (normal areas could wind up cool). For Europe, some of the area shown as near normal in Western Europe might be somewhat below normal. The general ideas of warmth across much of the eastern CONUS and cold in Europe, with the cold in Europe centered farther east, appear reasonable.

The objective analogs centered around 2/23 and rolled forward 3 days highlight the possibility of more expansive cold in the Pacific Northwest (and they show much of the northern tier colder than normal) and more cold in Western Europe. In my view, given the expected teleconnections, the objective analogs are overdone on the cold in North America. It would not be the first time the objective analogs are overdone on the cold this "non-winter" in North America.

Finally, the MJO is racing through Phase 8. By the start of March, some of the guidance suggests it could be well through Phase 2. If so, there is a growing risk that the MJO could spend much of the month in the phases that predominated during December, January, and early February, as its rate of progression will very likely decelerate at some point. The CFSv2 is quite aggressive with the forecast warmth for March. Warmer analogs, including 1974, 1985 and 2000 are increasing in the mix of possible candidates for March. All said, the probability of a mild or warm March in many areas that experienced an unseasonably warm winter is probably rising. Things can still change over the next few weeks, so it's too soon for me to be certain of the outcome. The evolution of the La Niña will likely play a key role in shaping the March outcome.

[am19psu]

The following posted message in the climate change forum offers my view concerning the variability seen in Winter 2011-12 (excessive North America warmth, severe cold in Europe, etc.) and where the impact of climate change can perhaps be seen: http://www.americanw...ost__p__1329666. A full discussion of the possible role of climate change is beyond the scope of this thread. Therefore, I provided the above link.

Don, thanks for steering the climate change discussion to appropriate forum

[Ottawa Blizzard]

February 23-29, 2012 Thoughts...

With temperatures in the teens in parts of New England and 20s in the Mid-Atlantic, it feels wintry today. However, just as had been the case time and again during this winter, the period of cold is likely to be brief. Down the road, the closing week of February looks to close perhaps pretty much as the month began: warm across much of North America and cold across large parts of Europe.

The composite temperature anomalies based on ENSO Region 3.4 anomalies of -1.55°C to -0.70°C, an AO of 0.00 to +1.50, and a PNA of -1.00 to 0.00 for the 2/20-29/1950-2011 timeframe for North America and Europe are below:

With the CPC site not updating the spread of the GFS ensemble members for the teleconnections, there is greater uncertainty than usual. For North America, a larger portion of the Pacific Northwest could wind up cooler than shown on the composite (normal areas could wind up cool). For Europe, some of the area shown as near normal in Western Europe might be somewhat below normal. The general ideas of warmth across much of the eastern CONUS and cold in Europe, with the cold in Europe centered farther east, appear reasonable.

The objective analogs centered around 2/23 and rolled forward 3 days highlight the possibility of more expansive cold in the Pacific Northwest (and they show much of the northern tier colder than normal) and more cold in Western Europe. In my view, given the expected teleconnections, the objective analogs are overdone on the cold in North America. It would not be the first time the objective analogs are overdone on the cold this "non-winter" in North America.

Finally, the MJO is racing through Phase 8. By the start of March, some of the guidance suggests it could be well through Phase 2. If so, there is a growing risk that the MJO could spend much of the month in the phases that predominated during December, January, and early February, as its rate of progression will very likely decelerate at some point. The CFSv2 is quite aggressive with the forecast warmth for March. Warmer analogs, including 1974, 1985 and 2000 are increasing in the mix of possible candidates for March. All said, the probability of a mild or warm March in many areas that experienced an unseasonably warm winter is probably rising. Things can still change over the next few weeks, so it's too soon for me to be certain of the outcome. The evolution of the La Niña will likely play a key role in shaping the March outcome.

Don. how is it looking for southern Ontario and Quebec? It doesn't look to turn as warm this upcoming week, with temperatures in the low to mid 30s as opposed to low to mid 40s.

[donsutherland1]

Don. how is it looking for southern Ontario and Quebec? It doesn't look to turn as warm this upcoming week, with temperatures in the low to mid 30s as opposed to low to mid 40s.

The 2/23-29 timerame will probably be somewhat above normal in that area. A day or two with very warm temperatures is possible.

[weathafella]

I'm with you snowstorms I think this whole climate change business is silly to say the least I mean cmon the arctic was melting in the 1920s but you don't dare here that today. And I agrre with you on how this mild winter is caused by the natural factors like the EPO and NAO etc and not Global Warming.

Who blamed this anomalous winter on gw? Certainly not Don. Don has been positively stellar in his analysis this entire winter.

[Srain]

Don, thanks for steering the climate change discussion to appropriate forum

Who blamed this anomalous winter on gw? Certainly not Don. Don has been positively stellar in his analysis this entire winter.

Take this to the CC forum. Thanks...

[Ginx snewx]

Who blamed this anomalous winter on gw? Certainly not Don. Don has been positively stellar in his analysis this entire winter.

Yes Don has been awesome, some day folks will understand climate change is not a regional seasonal process. March sure looks ugly again.