Joe bastardi cancels January in the east

[donsutherland1]

I believe the only reason 1993-94 ended up so cold amidst a slew of mild winters was because of the Mount Pinatubo effect.

Ottawa Blizzard,

I agree with you. I believe Mt. Pinatubo was a major reason that 1994 experienced its extreme arctic outbreak.

Places like the mid-atlantic, Ohio valley and western Europe may indeed see cold and snowy conditions again, but the fact is that regions like that are not supposed to see cold and snow like that - it's a novelty down there. Areas that traditionally receive cold and snow on a sustained basis have not been seeing it as often. Ski hill operators, as well as the ice fishing business rely on severe cold for their income, but they have not been getting it lately - see Michigan for example. JB is hinting that we may see winters like the late 70s within the next few years, but will this just be where his subscriber base is, or will this be up in Ontario/Quebec as well? Time will tell.

Unfortunately, I suspect that he is referring to where his subscriber base is. Now, if some winters were truly like the late 1970s, then Canada would also experience some notable cold. I'm skeptical that there will be similar winters, in terms of cold, anytime soon. During the late 1970s, the Artic was very cold. In contrast, today it is warmer. There's simply not enough cold to tap for the kind of sustained cold anomalies that resulted during the late 1970s. Extreme blocking would focus the cold as it did in 2009-10 and 2010-11, but the cold wouldn't be as widespread as the late 1970s due to less cold air being available. A similar synoptic pattern, even if it occurs, would not result in the same surface temperature outcome.

[BethesdaWX]

Ottawa Blizzard,

I agree with you. I believe Mt. Pinatubo was a

major reason that 1994 experienced its extreme arctic outbreak. Unfortunately, I suspect that he is referring to where his subscriber base is. Now, if some winters were truly like the late 1970s,

then Canada would also experience some notable

cold. I'm skeptical that there will be similar winters, in terms of cold, anytime soon. During

the late 1970s, the Artic was very cold. In contrast, today it is warmer. There's simply not enough cold to tap for the kind of sustained cold

anomalies that resulted during the late 1970s.

Extreme blocking would focus the cold as it did in 2009-10 and 2010-11, but the cold wouldn't be as widespread as the late 1970s due to less cold air being available. A similar synoptic

pattern, even if it occurs, would not result in the same surface temperature outcome.

I think you're really overstating the impact here, the northern hemisphere above 20N is only about 1.5F warmer now than it was in the 1970s, and since then the arctic has warmed about 1C. Though clearly it's the land masses that deviate more, and the higher lattitudes, so the difference you'd find in southern Canada would be maybe 4-5F assuming the higher end.

Most of the difference in winters arctic events in my opinion seems to correlate to a combo of the AO and AMO, related to thermal distribution rather than warming knowing 1C in the arctic lower troposphere (potential for cold to grow) is not really measurable in the "static" base of temperature variability. Also the winter ice pack doesn't have nearly the coverage change nor the impact on anomalies that the summer icepack decrease has/does.

There are record cold and warm anoms set on a daily basis all over the NH because the static nature of temperature range feature a wide potential in viable capability.

[Isotherm]

Unfortunately, I suspect that he is referring to where his subscriber base is. Now, if some winters were truly like the late 1970s, then Canada would also experience some notable cold. I'm skeptical that there will be similar winters, in terms of cold, anytime soon. During the late 1970s, the Artic was very cold. In contrast, today it is warmer. There's simply not enough cold to tap for the kind of sustained cold anomalies that resulted during the late 1970s. Extreme blocking would focus the cold as it did in 2009-10 and 2010-11, but the cold wouldn't be as widespread as the late 1970s due to less cold air being available. A similar synoptic pattern, even if it occurs, would not result in the same surface temperature outcome.

The late 70s winters occurred at a time when, meteorologically, global indicators favored a colder regime overall. The PDO turned negative in the 1940s, persisting through the end of the 1970s before flipping around 1979. In addition, the AMO became negative by the mid 1960s, and bottomed out in the 1970s w/ it's most severely negative values. So by the mid/late 1970s we had a situation where the PDO had been in its cold phase for 30 years and the AMO in its cold phase for 10+ years. That in conjunction with the more frequent -ENSO episodes allowed global temperatures to be supportive of widespread and severe chill. Right now, we've just transitioned out of 30 years of +PDO, the AMO turned warm in the mid 1990s, and is still warm (although we're seeing a temporary drop over the next several months; I expect the AMO will return positive as we've still got at least 10 years remaining in its warm cycle).

I anticipate the winters in the 2020-2030 time frame to potentially feature just as much cold if not more severe than the 1970s, as we bottom out in the cold AMO, conitnue with extremely low solar activity, and build up 10-15 years of a -PDO.

I'm not sure what you meant by "anytime soon" but if you're talking about now, then I agree, we won't compete with the 70s. 10+ years down the road, I disagree.

[donsutherland1]

I'm not sure what you meant by "anytime soon" ...

I meant at least for the next several winters.

[donsutherland1]

The late 70s winters occurred at a time when, meteorologically, global indicators favored a colder regime overall. The PDO turned negative in the 1940s, persisting through the end of the 1970s before flipping around 1979. In addition, the AMO became negative by the mid 1960s, and bottomed out in the 1970s w/ it's most severely negative values. So by the mid/late 1970s we had a situation where the PDO had been in its cold phase for 30 years and the AMO in its cold phase for 10+ years. That in conjunction with the more frequent -ENSO episodes allowed global temperatures to be supportive of widespread and severe chill. Right now, we've just transitioned out of 30 years of +PDO, the AMO turned warm in the mid 1990s, and is still warm (although we're seeing a temporary drop over the next several months; I expect the AMO will return positive as we've still got at least 10 years remaining in its warm cycle).

With respect to the contribution of those cycles, I strongly agree. That's another reason prospects of seeing winters rivaling those of the late 1970s in the next few years are probably very low.

[The_Global_Warmer]

The late 70s winters occurred at a time when, meteorologically, global indicators favored a colder regime overall. The PDO turned negative in the 1940s, persisting through the end of the 1970s before flipping around 1979. In addition, the AMO became negative by the mid 1960s, and bottomed out in the 1970s w/ it's most severely negative values. So by the mid/late 1970s we had a situation where the PDO had been in its cold phase for 30 years and the AMO in its cold phase for 10+ years. That in conjunction with the more frequent -ENSO episodes allowed global temperatures to be supportive of widespread and severe chill. Right now, we've just transitioned out of 30 years of +PDO, the AMO turned warm in the mid 1990s, and is still warm (although we're seeing a temporary drop over the next several months; I expect the AMO will return positive as we've still got at least 10 years remaining in its warm cycle).

I anticipate the winters in the 2020-2030 time frame to potentially feature just as much cold if not more severe than the 1970s, as we bottom out in the cold AMO, conitnue with extremely low solar activity, and build up 10-15 years of a -PDO.

I'm not sure what you meant by "anytime soon" but if you're talking about now, then I agree, we won't compete with the 70s. 10+ years down the road, I disagree.

Do you think it is possible that the positive AMOs would have started in the late 1980s. without the vocanic eruptions?

[BethesdaWX]

Do you think it is possible that the positive AMOs would have started in the late 1980s. without the vocanic eruptions?

I know you're not asking me but I can't help chiming in. I think the Sun is what drives the PDO, AMO, and ENSO, my family is full of solar physicists. So I do not believe volcanism really effects the AMO phase.

The AMO and PDO seem to flip every two solar cycles, at the maxes. PDO has been negative since 1998/99, AMO should be negative within 3 years. ENSO correlates to the geomag pulse referenced in the AP index on a lag of 6 years. I had no idea about that until my bro went into detail with md there and you can see all the ENSO events in there.

[Ottawa Blizzard]

If there were to be a volcanic eruption similar to the Tambora eruption of 1815 within the next couple of years, do you think it would have a similar impact on the weather? Obviously I hope there isn't such an eruption as it would likely kill thousands of people.

[OSUmetstud]

If there were to be a volcanic eruption similar to the Tambora eruption of 1815 within the next couple of years, do you think it would have a similar impact on the weather? Obviously I hope there isn't such an eruption as it would likely kill thousands of people.

lol...of course there would be a major climate impact if a tambora sized eruption happened today.

[bluewave]

The reason that we are not seeing the big arctic intrusions into the East is mostly due to the shift

in the wintertime arctic pattern.The most dramatic change occurred in the late 1990's after the AMO

switched into positive mode. In order to get record lows in places like NYC you need a big positive

height anomaly just north of Alaska. Since the mid 90's you'll notice a weakness with lower heights

dominating north of Alaska. A recent paper documents the dramatic warming of the current into

the Arctic which began in 1999. We have also experienced record warmth and blocking in the

Arctic since then.

http://ntrs.nasa.gov..._2011024624.pdf

while the fourth began in 1999 and persists at least through 2009. This most recent warm event is anomalous in other ways as well, being the strongest, having the broadest geographic extent, being surface-intensified, and occurring under exceptional meteorological conditions.

Jan 78-94

Jan 95-11

You can see that the pattern necessary for record cold around NYC has been mostly lacking since the mid 90's

but in 2004 we were able to get to get record into the NYC area with with ridging north of Alaska.

January's with record lows near NYC

January 2004 pattern

[Jonger]

I think you're really overstating the impact here, the northern hemisphere above 20N is only about 1.5F warmer now than it was in the 1970s, and since then the arctic has warmed about 1C. Though clearly it's the land masses that deviate more, and the higher lattitudes, so the difference you'd find in southern Canada would be maybe 4-5F assuming the higher end.

Most of the difference in winters arctic events in my opinion seems to correlate to a combo of the AO and AMO, related to thermal distribution rather than warming knowing 1C in the arctic lower troposphere (potential for cold to grow) is not really measurable in the "static" base of temperature variability. Also the winter ice pack doesn't have nearly the coverage change nor the impact on anomalies that the summer icepack decrease has/does.

There are record cold and warm anoms set on a daily basis all over the NH because the static nature of temperature range feature a wide potential in viable capability.

Bingo. I really hate seeing these temp anomaly maps, they have micro sized incremental units that change from blue to dark red over the course of 1 degree. Looking at it at a glance is scary until you look at the key.

Our current temps could very well be identical to the 1910's profile.. yet we never compare to those... We use a timeframe (1970's) that was colder then the 100 year average and make a deep color chart off small increments.

[donsutherland1]

Our current temps could very well be identical to the 1910's profile.. yet we never compare to those... We use a timeframe (1970's) that was colder then the 100 year average and make a deep color chart off small increments.

Several quick things:

1. One can run the re-analysis for daily, monthly, seasonal data using the 1981-2010 base period. All temperature anomalies are relative to that period.

2. One can glean earlier global and hemispheric temperature records from such databases as GISS (one of the more robust datasets), among others.

3. One can examine trends in outcomes dependent, in part, on temperatures, i.e.,glaciation, Arctic sea ice (coverage, thickness, etc.) to help corroborate temperature data.

In sum, one can have a fairly good idea as to how things have been evolving in the Arctic. The discussion as to why things have been happening over the long-term is a matter of climate and is better left for the climate change forum. What's relevant for forecasting is what changes have been taking place and how they impact forecasts.

[Jonger]

Several quick things:

1. One can run the re-analysis for daily, monthly, seasonal data using the 1981-2010 base period. All temperature anomalies are relative to that period.

2. One can glean earlier global and hemispheric temperature records from such databases as GISS (one of the more robust datasets), among others.

3. One can examine trends in outcomes dependent, in part, on temperatures, i.e.,glaciation, Arctic sea ice (coverage, thickness, etc.) to help corroborate temperature data.

In sum, one can have a fairly good idea as to how things have been evolving in the Arctic. The discussion as to why things have been happening over the long-term is a matter of climate and is better left for the climate change forum. What's relevant for forecasting is what changes have been taking place and how they impact forecasts.

4. Current pattern is the result of a lack of block.... not 1 degree of "climate change".

Trying to tie this to anything else is worth investigating, but deep down you know what the cause is. Its also bad information to try and give to the public as they have next to NO idea what AO and PNA or ENSO is.

[easternsnowman]

I believe as Bethesda said that the sun is the main player in the warming and I think the rest all plays a minor role.

[The_Global_Warmer]

4. Current pattern is the result of a lack of block.... not 1 degree of "climate change".

Trying to tie this to anything else is worth investigating, but deep down you know what the cause is. Its also bad information to try and give to the public as they have next to NO idea what AO and PNA or ENSO is.

I should remind you that the AMO index changes from positive to negative on less than a 1 degree of "temperature change".

The arctic has changed by far more than 1 degree of "temperature change".

Don needs utilize every tool he can to make forecasts if that is what he choosing to do. I am not trying to say the AMO index does not matter, but it is used by many as a must have end all be all tool and it is based on very very small temperature fluxuations at the surface of the Atlantic. Remember that when saying someone shouldn't incorporate other changes.

If Analog year say 1958 is on average 3C colder between 60-90N than 2011 between September 1st and November 15th and it's November 18th 2011 it may be wise to say maybe that matter, even if height anomalies are similiar. That indicates that the cold pool where our cold air is from is warmer than the analog year.

But even more wise would be to do that and track it against a long term trend. And recently the cold pool is not as cold. If a pool of air over the Northern Third of Canada is making it's way down to us on January 29th with all over parameters the exact same. The air will end up warmer in the end vs air that is colder threw moderation. This is simple and is important information in a changing climate.

That is just scratching the surface of what proper data analyzation can do. This is not about AGW. How many times does that have to be stated? If the climate cooled just as much as it as warmed I am sure Don and whomever else would take notice and talk about it. Would the same resistance to this be met? I want to make the best forecasts I can & I want Don to make the best he can so when I read his work there is a higher chances it will be legit & correct. Proper data assimilation is the key to that.

[Roger Smith]

Getting back to the main theme of this thread, Joe may have cancelled January, but I am going to un-cancel Jan 18-31 and say that's about where pattern change is likely to develop leading to a good if not blockbuster February. So maybe cancel first half of January?

On the subject of eastern Canada cold fading out in recent years, feel that it can't be entirely related to any concept of human-based climate change in any case, too many exceptions including the severe cold in 1994 and the very heavy snowfalls in some places in later part of winter 2008. No doubt it's a natural variation that could easily be overcome by the right synoptics. Lake effect snow for example does not seem to have suffered as much as synoptic scale snowfall in Ontario, during the postulated warm period. And also in there you have the mega-snows of Jan 1999.

At this stage of the winter of 1965-66, had there been a forum, I'm sure there would be mass poster suicides and cancellations all round, it was about 70 degrees in New York City on New Years Eve that winter with a thunderstorm raging. Took about ten days for some process to get rid of that regime, another ten to set up a good one, and then boom. Didn't last all that long either, but memorable winters are not always long-duration in terms of cold and snow.

[donsutherland1]

Don needs utilize every tool he can to make forecasts if that is what he choosing to do. I am not trying to say the AMO index does not matter, but it is used by many as a must have end all be all tool and it is based on very very small temperature fluxuations at the surface of the Atlantic. Remember that when saying someone shouldn't incorporate other changes.

If Analog year say 1958 is on average 3C colder between 60-90N than 2011 between September 1st and November 15th and it's November 18th 2011 it may be wise to say maybe that matter, even if height anomalies are similiar. That indicates that the cold pool where our cold air is from is warmer than the analog year.

But even more wise would be to do that and track it against a long term trend. And recently the cold pool is not as cold. If a pool of air over the Northern Third of Canada is making it's way down to us on January 29th with all over parameters the exact same. The air will end up warmer in the end vs air that is colder threw moderation. This is simple and is important information in a changing climate.

That is just scratching the surface of what proper data analyzation can do. This is not about AGW. How many times does that have to be stated? If the climate cooled just as much as it as warmed I am sure Don and whomever else would take notice and talk about it. Would the same resistance to this be met? I want to make the best forecasts I can & I want Don to make the best he can so when I read his work there is a higher chances it will be legit & correct. Proper data assimilation is the key to that.

Very well said.

Medium- and longer-range forecasts are very difficult. I try to utilize every possible tool can provide some useful insight. Climatic change is something that has to be considered (one can discuss the causes of climate change itself in the climate forum), as the outcome is something that can provide insight into a medium- and especially longer-range forecasts.

Indeed, if one paid attention to the Arctic anomalies in November/early December 2001, one would have noted widespread and persistent warmth. Hence, when strong blocking occurred during the second half of December 2001, one saw abnormally mild conditions for a blocking regime later in eastern North America. Indeed, the November Northern Hemisphere anomaly was +0.94°C (GISS). Had one ignored the persistent and notable warmth at the high latitudes, one might have assumed that the strong blocking regime that occurred during the second half of December would have produced unseasonably cold readings in eastern North America, much like what occurred during December 2009 and 2010. The appropriate question concered where would the severe cold come from if the Arctic was so warm and only small pockets of very cold anomalies were present in the Northern Hemisphere? Instead, the best one could probably hope for was glancing blows of cold, as the expansive of unseasonable cold was too small to have confidence that eastern North America would grow very cold.

The same also applies for seasons as a whole. If the Arctic is notably warmer than decades past, one would do well to incorporate an adjustment when it comes to expected 500 mb patterns derived from ENSO/ENSO evolution + teleconnections.

Of course, that does not ensure consistently accurate forecasts. Longer-range forcasting is very difficult. However, it probably does increase the odds of doing better than might otherwise be the case.

[donsutherland1]

4. Current pattern is the result of a lack of block.... not 1 degree of "climate change".

I never said otherwise. The climatic impact is an adjustment to the surface conditions from the expected pattern. If one goes to the medium range thread, one sees my use of the teleconnections e.g., AO.

[BethesdaWX]

I believe as Bethesda said that the sun is the main player in the warming and I think the rest all plays a minor role.

*Indirectly* the main cause, yes that is my hypothesis. So many answers are hidden in albedo.

The reason the climate and weather patterns are chaotic and constantly molding/evolving is due to constant changes in location of incoming vs outgoing energies (imbalance) through the operations/changing locations of atmospheric albedo [clouds] that act as both a feedback to thermal change and as a forcing through external influence on the AO and AAO.

Configuration of atmospheric albedo changes significantly with the AO oscillation, very notable decrease in earthshine over the 30N to 30S region during the -AO, as well as more earthshine elsewhere. Big Big significance in that for both the OHC, global temp/humidity, and ENSO too since global winds are driven by heat dispersion, which is altered by the manner of albedo. That is why the geomag sun correlates to ENSO on a 6 year lag.

My broder' introduced me to all this and it's fascinating once you delve into it all.

[BethesdaWX]

I never said otherwise. The climatic impact is an adjustment to the surface conditions from the expected pattern. If one goes to the medium range thread, one sees my use of the teleconnections e.g., AO.

How do surface temperature changes of merely 1.5F over 30yrs in the NH equate to the changes we've seen in thermal (airmass) dispersion? That'd fall more in line with the AMO/AO/Earthshine thing I'd think, which can also explain large changes in total albedo of over +7W/m^2 since 1979, versus 0.8W/m^2 from changes in CO2 and H2O which could very well be a result of the change in albedo at least partially.

[BethesdaWX]

Very well said.

Medium- and longer-range forecasts are very difficult. I try to utilize every possible tool can provide some useful insight. Climatic change is something that has to be considered (one can

discuss the causes of climate change itself in the climate forum), as the outcome is something that can provide insight into a medium- and especially longer-range forecasts.

Indeed, if one paid attention to the Arctic anomalies in November/early December 2001, one would have noted widespread and persistent warmth. Hence, when strong blocking occurred during the second half of December 2001, one saw abnormally mild conditions for a blocking regime later in eastern North America. Indeed, the November Northern Hemisphere anomaly was +0.94°C (GISS). Had one ignored the persistent and notable warmth at the high latitudes, one might have assumed that the strong blocking regime that occurred during the second half of December would have produced unseasonably cold readings in eastern North America, much like what occurred duringDecember 2009 and 2010. The appropriate question concered where would the severe cold come from if the Arctic was so warm and only small pockets of very cold anomalies were present in the Northern Hemisphere? Instead, the best one could probably hope for was glancing blows of cold, as the expansive of unseasonable cold was too small to have confidence that eastern North America would grow very cold.

The same also applies for seasons as a whole. If the Arctic is notably warmer than decades past, one would do well to incorporate an adjustment when it comes to expected 500 mb patterns derived from ENSO/ENSO evolution + teleconnections.

Of course, that does not ensure consistently

accurate forecasts. Longer-range forcasting is very difficult. However, it probably does increase the odds of doing better than might otherwise be the case.

It seems implausible in my personal opinion for a warming in the Arctic lower troposphere (potential for cold air growth) by 1.2C since the mid 1970s to have any significant impact on the strength of arctic cold waves, what bluewave posted earlier I think somewhat highlights the AMO/earthshine thing.

In the Midwest, over the past 6 years, there have been numerous blasts with temps falling into the -40s and also -50s, in setups not as prolific as colder ones in the past, to boot.

[donsutherland1]

It seems implausible in my personal opinion for a warming in the Arctic lower troposphere (potential for cold air growth) by 1.2C since the mid 1970s to have any significant impact on the strength of arctic cold waves, what bluewave posted earlier I think somewhat highlights the AMO/earthshine thing.

In the Midwest, over the past 6 years, there have been numerous blasts with temps falling into the -40s and also -50s, in setups not as prolific as colder ones in the past, to boot.

The data says otherwise. While there have been some severe shots of cold (and I never said there won't be), winters have warmed between the 1971-00 and 1981-10 base periods. The National Climatic Data Center's presentation on the 1981-10 changes provides a hint of that e.g., January minimum temperatures (most aggressive warming has been in the Northern Plains).

http://www.ncdc.noaa...cast-061311.pdf

In terms of the frequency of severe Arctic blasts, Bismarck offers an example. During the 1980s, there were 20 days on which the temperature fell to -30°F or below. During the 1990s, there were 16 such days. Since 2000, there have been 5 such days. From a long-range forecasting standpoint, when one is estimating what a winter might be like, the diminished frequency of such severe cold shots has significance. In the near-term, when one has the luxury of seeing air masses before they invade the Plains, one can rely on the modeling/ensembles for insight that is not available for monthly/seasonal forecasting.

From the forecasting standpoint, it is the trend (warming) that matters. The natural (e.g., cyclical) + anthropogenic forcings responsible are matters better left to the climate change forum for discussion.

NOTE: Similar trends to Bismarck can be found in many other cities. For example, when it comes to Washington, DC (DCA), the 1980s saw 17 days on which the temperature fell below 10°F. During the 1990s, there were 9 such days. Since 2000, only 2 days had minimum temperatures below 10°F.

[BethesdaWX]

The data says otherwise. While there have been some severe shots of cold (and I never said there won't be), winters have warmed betwe

en the 1971-00 and 1981-10 base periods. The National Climatic Data Center's presentation on the 1981-10 changes provides a hint of that e.g., January minimum temperatures (most aggressive warming has been in the Northern Plains).

http://www.ncdc.noaa...cast-061311.pdf

In terms of the frequency of severe Arctic blasts, Bismarck offers an example. During the 1980s, there were 20 days on which the temperature fell to -30°F or below. During the 1990s, there were 16 such days. Since 2000, there have been 5 such days. From a long-range forecasting standpoint, when one is estimating what a winter might be like, the diminished frequency of such severe cold shots has significance. In the near-term, when one has the luxury of seeing air masses before they invade the Plains, one can rely on the modeling/ensembles for insight that is not available for monthly/seasonal forecasting.

From the forecasting standpoint, it is the trend (warming) that matters. The natural (e.g., cyclical) + anthropogenic forcings responsible

are matters better left to the climate change forum for discussion.

NOTE: Similar trends to Bismarck can be found in many other cities. For example, when it comes to Washington, DC (DCA), the 1980s saw 17 days on which the temperature fell below 10°F. During the 1990s, there were 9

such days. Since 2000, only 2 days had minimum temperatures below 10°F.

Thankyou for the good read.

A couple things

Is weighting the 30yr mean viable? Wintertime temps overall in the US went down from the 1990s to the 2000s, and via NSIDC all regions in the US experienced a cooling winter average this past decade. The 1970s cool period being removed in the 1981/2010 base period will definitely increase the average.

Also t what I think the problem is, causation versus correlation. Because the NH north of 20N is 1.5F warmer in now than it was in the 1970s doesn't mean the decrease in arctic intrusion is necessarily caused by that minute difference in temperature, but rather what could causing it in the first place, thermal dispersion related to several factors mirrored in the AMO (correlating to) solar influence (doesnt mean causation either). I am not convinced CO2 is adequately dispersed in the atmosphere to have any significant impact on the total global RF

budget, (GEOCARB proxy analysis supports this), but even if I'm wrong the RF potential is 1/7 that of Albedo since the 1970s in 0.8W/m^2.

[usedtobe]

Thankyou for the good read.

A couple things

Wintertime temps overall in the US went down from the 1990s to the 2000s, and via NSIDC all regions in the US experienced a cooling winter average this past decade. The 1970s cool period being removed in the 1981/2010 base period will definitely increase the average.

Also t what I think the problem is, causation versus correlation. Because the NH north of 20N is 1.5F warmer in now than it was in the 1970s doesn't mean the decrease in arctic intrusion is necessarily caused by that minute difference in temperature, but rather what could causing it in the first place, thermal dispersion related to several factors mirrored in the AMO (correlating to) solar influence (doesnt mean causation either). I am not convinced CO2 is adequately dispersed in the atmosphere to have any significant impact on the total global RF

budget, (GEOCARB proxy analysis supports this), but even if I'm wrong the RF potential is 1/7 that of Albedo since the 1970s in 0.8W/m^2.

This article suggests that eh hemispheric warming is not related to the ao or nao.

http://journals.ametsoc.org/doi/pdf/10.1175/JCLI3530.1

The argument you are making does not belong in the weather forum. It belongs in the climate forum.

[am19psu]

The argument you are making does not belong in the weather forum. It belongs in the climate forum.

Let's try to keep this thread and the stratospheric thread on topic, please. If you'd like to discuss climate change related issues, feel free to take them to the Climate Change forum.

[donsutherland1]

BethesdaWX,

The issue of causation and correlation, not to mention the role of forcings (natural, CO2, etc.) is something better left for the climate change forum. I'm using the data to assess probabilities and uncertainty. The frequency of severe to extreme Arctic outbreaks has diminished--at least for the time being--in large parts of the U.S. The Bismarck and Washington, DC figures are just examples.

Hence, if one raised the question as to what are the chances that, let's say, Washington, DC will see a severe Arctic intrusion with one or more single digit readings this winter, the answer would be that the probability is low. That's the starting point.

Then, one would need to refine the probability. To do so, one would need to look upstream to source regions of such air masses and then the expected patterns associated with the current ENSO/ENSO evolution (ongoing + forecast) with various scenarios (blocking vs. no blocking, PNA+ vs. PNA-) and then provide the "best guess" for the frequency of such scenarios. With the strong PDO- regime in place, odds favor weaker PNA+/more frequent PNA- regimes. Historic experience with powerful December AO+ regimes point to a winter where the AO will likely be predominantly positive. That each modeled hint of an SSW has ultimately faltered, including the most recent one, lends confidence that the predominant AO+ regime might have to end from bottom-up developments, not top-down ones. All of this information then ties back to the low probability that was the initial hypothesis. That hypothesis is strengthened in the case of what appears likely during Winter 2011-12. Also, given this context, if one sees the GFS indicating such severely cold readings 12-16-days out, one can probably expect moderation on the modeling as the event draws closer.

In the end, given the vast uncertainty with longer-horizon forecasting, any insight that might have utility is something that should not be readily dismissed.

[BethesdaWX]

This article suggests that eh hemispheric warming is not related to the ao or nao.

http://journals.ametsoc.org/doi/pdf/10.1175/JCLI3530.1

The argument you are making does not

belong in the weather forum. It belongs in the

climate forum.

I apologize. I was trying to give an example

case in point determining between whether

treating temperature change and arctic airmass intrusion should be done as a cause-effect relationship or a process of thermal feedback or something else.

I wasn't trying to compare the AO to hemispheric temp change, but instead the AO and AMO to synoptic shifts in the large scale that could effect the number of arctic outbreaks into the US that may happen to concede with temp change, knowing the arctic lower troposphere has warmed merely 1.2C since the late 1970s regardless of the underlying causation.

I'm at the airport on the iPhone so I'm sure I sound incoherent right now. Sorry to waste bandwidth. I had no intention to directly involve CC forum issues but they do unfortunately relate I think.

[MJO812]

Now JB is saying January will be cold for the east coast.

[Brian5671]

Now JB is saying January will be cold for the east coast.

if that verifies, he will have busted horribly on December and then finally goes warm for Jan only to see it verify cold....maybe he should go for a hurricane hit in February.

[winter_warlock]

Now JB is saying January will be cold for the east coast.

JB is always either over hyping a storm , or his monthly preditcions will be wrong. now there are times he will have a hit, but as they say" even a broke clock is right twice a day".. so i tend to not really pay attention to his long range forecasts.