1.5 month lead forecast

[Typhoon Tip]

This is intended to be a 45 day outlook

Potentially Interesting developments in the upper altitudes over the Arctic domain. There is emerging a warm anomaly in the ~1mb sigma level of the stratosphere.

I was also discussing this with a Meteorologist the other day who was noting the GFS ensemble prediction system indicating a substantial SWE to take place of the next 3 weeks. Stratospheric Warming Events have a climatology for post December 30 where such events in the first half of the month are comparatively rare phenomenon. Nonetheless, there are no absolutes in this business as we at times are regretfully reminded. It would also be necessary to determine whether such an event this go would be of the downward propagating variety, as I have written many discussions elucidating this key behavior back in late 2005 (hard to believe it has been 5 years). Static altitude warming or cooling events are less correlated to enhancing the AO when time-lag is applied. I have demonstrated this in the past a few times with annotated imagery, which indeed lead subsequent notable intervals of -AO/-NAO coupled states. Case in point was that which took place in early January of 2006:

What followed 20 days later was a dramatic shift in the polar field teleconnector status' compared to earlier that autumn and early winter. Whopping positive anomalies in both the AO/NAO domains were nearly reversed, and so did the temperature anomaly distribution really over the entirety of the Northern Hemisphere to close out January 2007 and throughout much of February that winter. That is just one example; there are quite a few and enough of a large sample set to argue very strongly to a causal correlation.

Below is the GFS ensemble system outlook for the higher altitudes over the arctic/polar latitudes. We see that between D5 and D10 there are some notable changes:

What this will mean for the sensible weather on this side of the hemisphere is not entirely clear due to the fact that for the time being the signal has weak coherence for being so young in cycle. For reasons below, the intuitive answer is that these may very well be the early indicators pointing toward locking in colder than normal pattern.

We have been enduring a -AO/-NAO couplet for about 2-3 weeks as we know, but then this suggests we relay [potentially] out of a planetary forcing (or not) era into one where forcing comes from above. This latter form of warming stratosphere “pancakes” the latitude of the mean hemispheric band of westerlies. The primer there is that warming in the lower stratosphere and tropopausal depths supplies positive static stability in the ambient field, and that limits the amount of vertical motion overall, and blocking at high latitudes becomes predominant. This would be taking place whether the current phase of planetary wave forcing leading to -NAO has alleviated or not. That said, superimposing the two factors (should the take place concurrently) would assert a very impressive -AO/-NAO persistence, meeting the staggering -SD depatures of last year plausible.

Reasoning: It should not really be unexpected during the current era of solar cycle, and attending negatively differentiating AMO. Chicken or egg? Take your pick, but that answer bears little beyond nailing causal science – the fact remains, -NAO is favored because of both; the -AO counter part being more SC-related. During negative solar cycle the UV and visible light numbers switch anomalies. The sun is visibly brighter during negative (though not detectable by the naked eye), while the UV area of the spectrum is reduced. This reduction contributes to a build of higher altitude ozone particles due to the fact that chemical reactions aside, there is a proxy over ozone at those altitude by the nature of the solar irradiance. UV assists in breaking down ozone. Much of this is theoretical, but it is mathematically derived, as well as can be observed, so the relative strength of the science is impressive (whether the emerging -AMO is correlated is an interesting subset for study).

I believe as an analyst that this really argues for the disconnect between the ENSO and the polar field teleconnectors; I wanted to mention this because I've read about -NAOs not being statistically correlated with NINA type ENSO events in contexts that appear like absolution. Firstly, this statement is not supported by the linear correlation matrices at CDC for the month of December, but secondly, the erstwhile reasoning does not really assert that connection is necessary in the system at all times. Logically, the ENSO does not control the sun, which does appear to in part control the ozone concentrations that are correlated to the AO. So both statistically on the surface, and intuitive, it is not really true and one should not set expectations based on that assumption. I know there are subsets and quadrature analysis types that may find correlations that are not as represented by the system as a whole, but considering there are enough years in the last 100 where the antithetical ENSO /NAO resulted, perhaps those outliers are thus explained. The correlation between the ENSO and the NAO does get stronger in January (-2.0 coefficiency), and nears 3.0 in February; but we are statistically prone to -AO during that time. As I and undoubtedly others have described in the past, the AO and NAO share domain space; a +NAO can at time exist with a -AO, although that circumstance is rare. The pure AO is even less correlated with the ENSO, near 0 correlation coefficients in December grows to a weak -.16 in February. What this all really means objectively if that the ENSO can do whatever, if these polar field indices do not behave, there is no direct known process that would prevent that from happening and the implications mean the longer term NINA expectation may have less proxy that given season.

Let us not forget the cryosphere. The production of land-snow and sea-ice recovery et al was equally if not measured even faster than the impressive autumn of 2009.

This depiction has units of millions of sq(KM) in the vertical up the graph. The differences between 2009 and 2010 are ~1.5 million more sq(KM) over the record low years of 2007 and 2008. The very recent observation just to the naked eye does suggest that we have surpassed last year as of Dec 3 - I am currently trying to find more recent update.

It may be a weaker correlation over all, but it sits pretty for winter weather enthusiasts along 40N everywhere that we have not event exceeded the date of max expanse of 24 hour darkness above 66N, and that is doing so over a pervasive negative feedback from below. This should weight the lower troposphere ever more, increasing foresaid static stability – it is enough to almost think run-away cooling on an intra-annual time scale is underway, but I will stop shy of going extreme. Much of this is to base the canvas for now through mid Meteorological winters (Jan 15). I believe these factors will [probably] overwhelm the NINA, masking its influence at times of heavier SD occurrence, at other times allowing the more agreeable NINA type pattern to present. It would appear the era of warm departures in the OV, MA, and NE states is at an ends going forward. I believe below to much below normal departures will dominate through mid January.

To wrap this up ... I am sure what the range of negative departures will be, but that negative is overwhelmingly signaled. This may come as an obvious statement for a lot of readers, but this was attempt to simultaneously offer a prediction, but also discussed the philosophies behind choosing that course.

Precipitation in this regime would feature dry times that are occasionally compensated by smaller scale impulses such as clipper type waves, or SE/Gulf waves that attempt to Miller A. *However* and this is important, other seasons in the past that featured dynamic and strong polar field influences occasionally produce multiple stream phased type solutions. This is because whenever there is polar vortex anchored east of the PNAP preferred location of western Jame Bay (~), that makes translating Pacific polar stream impulses vulnerable to subsumed type phasing. This is when the polar (intermediate) stream impulse lowers the geopotential resistance S, and a portion of the vortex N severs, comes down, and together with the dynamics of the intermediate stream they close off as the system nears the OV or MA states. This type of event is also retrograde event as a whole, and sits well conceptually because -AO/-NAO is an in situ a retrograde characteristic. Unfortunately, this type of phenomenon can not really be predicted at extended leads, so I have to go along the assumption that the greater % of the time the streams will remain separate, and with a dominant -NAO that is essentially otherwise a drier flow with suppression of the westerlies between 100 and 60 W closing down the Gulf and Atlantic for deeper inflow.

John

[NinjaWarrior2]

This is intended to be a 45 day outlook

Potentially Interesting developments in the upper altitudes over the Arctic domain. There is emerging a warm anomaly in the ~1mb sigma level of the stratosphere.

I was also discussing this with a Meteorologist the other day who was noting the GFS ensemble prediction system indicating a substantial SWE to take place of the next 3 weeks. Stratospheric Warming Events have a climatology for post December 30 where such events in the first half of the month are comparatively rare phenomenon. Nonetheless, there are no absolutes in this business as we at times are regretfully reminded. It would also be necessary to determine whether such an event this go would be of the downward propagating variety, as I have written many discussions elucidating this key behavior back in late 2005 (hard to believe it has been 5 years). Static altitude warming or cooling events are less correlated to enhancing the AO when time-lag is applied. I have demonstrated this in the past a few times with annotated imagery, which indeed lead subsequent notable intervals of -AO/-NAO coupled states. Case in point was that which took place in early January of 2006:

What followed 20 days later was a dramatic shift in the polar field teleconnector status' compared to earlier that autumn and early winter. Whopping positive anomalies in both the AO/NAO domains were nearly reversed, and so did the temperature anomaly distribution really over the entirety of the Northern Hemisphere to close out January 2007 and throughout much of February that winter. That is just one example; there are quite a few and enough of a large sample set to argue very strongly to a causal correlation.

Below is the GFS ensemble system outlook for the higher altitudes over the arctic/polar latitudes. We see that between D5 and D10 there are some notable changes:

What this will mean for the sensible weather on this side of the hemisphere is not entirely clear due to the fact that for the time being the signal has weak coherence for being so young in cycle. For reasons below, the intuitive answer is that these may very well be the early indicators pointing toward locking in colder than normal pattern.

We have been enduring a -AO/-NAO couplet for about 2-3 weeks as we know, but then this suggests we relay [potentially] out of a planetary forcing (or not) era into one where forcing comes from above. This latter form of warming stratosphere “pancakes” the latitude of the mean hemispheric band of westerlies. The primer there is that warming in the lower stratosphere and tropopausal depths supplies positive static stability in the ambient field, and that limits the amount of vertical motion overall, and blocking at high latitudes becomes predominant. This would be taking place whether the current phase of planetary wave forcing leading to -NAO has alleviated or not. That said, superimposing the two factors (should the take place concurrently) would assert a very impressive -AO/-NAO persistence, meeting the staggering -SD depatures of last year plausible.

Reasoning: It should not really be unexpected during the current era of solar cycle, and attending negatively differentiating AMO. Chicken or egg? Take your pick, but that answer bears little beyond nailing causal science – the fact remains, -NAO is favored because of both; the -AO counter part being more SC-related. During negative solar cycle the UV and visible light numbers switch anomalies. The sun is visibly brighter during negative (though not detectable by the naked eye), while the UV area of the spectrum is reduced. This reduction contributes to a build of higher altitude ozone particles due to the fact that chemical reactions aside, there is a proxy over ozone at those altitude by the nature of the solar irradiance. UV assists in breaking down ozone. Much of this is theoretical, but it is mathematically derived, as well as can be observed, so the relative strength of the science is impressive (whether the emerging -AMO is correlated is an interesting subset for study).

I believe as an analyst that this really argues for the disconnect between the ENSO and the polar field teleconnectors; I wanted to mention this because I've read about -NAOs not being statistically correlated with NINA type ENSO events in contexts that appear like absolution. Firstly, this statement is not supported by the linear correlation matrices at CDC for the month of December, but secondly, the erstwhile reasoning does not really assert that connection is necessary in the system at all times. Logically, the ENSO does not control the sun, which does appear to in part control the ozone concentrations that are correlated to the AO. So both statistically on the surface, and intuitive, it is not really true and one should not set expectations based on that assumption. I know there are subsets and quadrature analysis types that may find correlations that are not as represented by the system as a whole, but considering there are enough years in the last 100 where the antithetical ENSO /NAO resulted, perhaps those outliers are thus explained. The correlation between the ENSO and the NAO does get stronger in January (-2.0 coefficiency), and nears 3.0 in February; but we are statistically prone to -AO during that time. As I and undoubtedly others have described in the past, the AO and NAO share domain space; a +NAO can at time exist with a -AO, although that circumstance is rare. The pure AO is even less correlated with the ENSO, near 0 correlation coefficients in December grows to a weak -.16 in February. What this all really means objectively if that the ENSO can do whatever, if these polar field indices do not behave, there is no direct known process that would prevent that from happening and the implications mean the longer term NINA expectation may have less proxy that given season.

Let us not forget the cryosphere. The production of land-snow and sea-ice recovery et al was equally if not measured even faster than the impressive autumn of 2009.

This depiction has units of millions of sq(KM) in the vertical up the graph. The differences between 2009 and 2010 are ~1.5 million more sq(KM) over the record low years of 2007 and 2008. The very recent observation just to the naked eye does suggest that we have surpassed last year as of Dec 3 - I am currently trying to find more recent update.

It may be a weaker correlation over all, but it sits pretty for winter weather enthusiasts along 40N everywhere that we have not event exceeded the date of max expanse of 24 hour darkness above 66N, and that is doing so over a pervasive negative feedback from below. This should weight the lower troposphere ever more, increasing foresaid static stability – it is enough to almost think run-away cooling on an intra-annual time scale is underway, but I will stop shy of going extreme. Much of this is to base the canvas for now through mid Meteorological winters (Jan 15). I believe these factors will [probably] overwhelm the NINA, masking its influence at times of heavier SD occurrence, at other times allowing the more agreeable NINA type pattern to present. It would appear the era of warm departures in the OV, MA, and NE states is at an ends going forward. I believe below to much below normal departures will dominate through mid January.

To wrap this up ... I am sure what the range of negative departures will be, but that negative is overwhelmingly signaled. This may come as an obvious statement for a lot of readers, but this was attempt to simultaneously offer a prediction, but also discussed the philosophies behind choosing that course.

Precipitation in this regime would feature dry times that are occasionally compensated by smaller scale impulses such as clipper type waves, or SE/Gulf waves that attempt to Miller A. *However* and this is important, other seasons in the past that featured dynamic and strong polar field influences occasionally produce multiple stream phased type solutions. This is because whenever there is polar vortex anchored east of the PNAP preferred location of western Jame Bay (~), that makes translating Pacific polar stream impulses vulnerable to subsumed type phasing. This is when the polar (intermediate) stream impulse lowers the geopotential resistance S, and a portion of the vortex N severs, comes down, and together with the dynamics of the intermediate stream they close off as the system nears the OV or MA states. This type of event is also retrograde event as a whole, and sits well conceptually because -AO/-NAO is an in situ a retrograde characteristic. Unfortunately, this type of phenomenon can not really be predicted at extended leads, so I have to go along the assumption that the greater % of the time the streams will remain separate, and with a dominant -NAO that is essentially otherwise a drier flow with suppression of the westerlies between 100 and 60 W closing down the Gulf and Atlantic for deeper inflow.

John

Your forecast looks like 2000-2001/2008-2009.

[skierinvermont]

Tip, everything else looks great and I am very excited to see how this turns out but I am a little confused by the sea ice claims. Extent this fall (Sep-present) has been the 2nd lowest only to 2007. We are currently near the lowest extent ever for the date, second only to 2006.

[nzucker]

Tip, everything else looks great and I am very excited to see how this turns out but I am a little confused by the sea ice claims. Extent this fall (Sep-present) has been the 2nd lowest only to 2007. We are currently near the lowest extent ever for the date, second only to 2006.

I think he is using a combination of snow cover and sea ice for this statistic. Also, he's talking about a rate of recovery.

[Typhoon Tip]

Tip, everything else looks great and I am very excited to see how this turns out but I am a little confused by the sea ice claims. Extent this fall (Sep-present) has been the 2nd lowest only to 2007. We are currently near the lowest extent ever for the date, second only to 2006.

...

Skier' HI -

That product is Sea Ice only though...

Firstly, I was discussing land and sea combined; 2ndly, I didn't mention any comparison beyond comparing 2009 and 2010, versus 2007 and 2008. In the graphical product I annotated showed that.

Having said that, yeah it does suck and shows an overall background GW is there - despite what appears to be a step back for the next decade. How much that is, who knows - or how long for that matter. But, solar cycling and getting low relative maxes amid real flat-line min s will correlated to -AOs, and this should offset for the next few years.

[Typhoon Tip]

I think he is using a combination of snow cover and sea ice for this statistic. Also, he's talking about a rate of recovery.

Precisely NZucker -

Also, I think it is the rate of change that is more telling. Every year, yeah ...the solar dims, the sea cools, and ice is recovered - but gaining TX-sized ice coverage in a single day is indicative of off-set cooling factors occurring in the system

[skierinvermont]

Skier' HI -

That product is Sea Ice only though...

Firstly, I was discussing land and sea combined; 2ndly, I didn't mention any comparison beyond comparing 2009 and 2010, versus 2007 and 2008. In the graphical product I annotated showed that.

Having said that, yeah it does suck and shows an overall background GW is there - despite what appears to be a step back for the next decade. How much that is, who knows - or how long for that matter. But, solar cycling and getting low relative maxes amid real flat-line min s will correlated to -AOs, and this should offset for the next few years.

Ah ok - missed that. I was a little confused by the graph because that appears to only run through september. At least with ice, we are way below last year and have been ~at or below last year's levels all fall. I know snow was doing poorly for a while in October but has been doing well recently.

[Yes_Probably_Maybe_No]

I believe these factors will [probably] overwhelm the NINA, masking its influence at times of heavier SD occurrence, at other times allowing the more agreeable NINA type pattern to present. It would appear the era of warm departures in the OV, MA, and NE states is at an ends going forward. I believe below to much below normal departures will dominate through mid January.

Some of this is a bit over my head, but when I read the plain english it's the best news I've heard all week. I have a question though.

This update is much appreciated.

Is there any chance you can either explain the pancaking idea or link me to a website? The warming event in the upper atmosphere coupled with the tropospheric -NAO/-AO will make any westerlies meaningless?

[ICEAGE NOW]

And alot of Volcano's this past year with ash going up into the upper air will have a effect on our winter ( Iceland Volcano )

[Typhoon Tip]

And alot of Volcano's this past year with ash going up into the upper air will have a effect on our winter ( Iceland Volcano )

This is a good point about Volcanism - I chose not to include it because in all honesty the effects of volcanic aerosols in the stratosphere, although known, I personally am less versed in that area of geo-sciences. My very basic understanding is that increased SO2 particulate matter is a cooling factor due to literally reflecting some fragment of the total solar budge back out into space before it has a chance to be absorbed and then transferred to kinetic temperature. That's as far as my understanding goes, and I am not really sure of residence (time it takes to cleanse), or what the volcano numbers were during the summer and autumn. As far as I am away Iceland's system has quieted down over the last several months.

[Typhoon Tip]

Some of this is a bit over my head, but when I read the plain english it's the best news I've heard all week. I have a question though.

This update is much appreciated.

Is there any chance you can either explain the pancaking idea or link me to a website? The warming event in the upper atmosphere coupled with the tropospheric -NAO/-AO will make any westerlies meaningless?

I will try to answer your question:

Basics, cool over warm = air rises.

Warm over cool = air falls or hold static.

That very simple model works at all scales, from the effects of opening a freezer door and observing the cold air fall and spread out along the floor, to the grandeur of the whole atmosphere of the earth - or any volume of gas more precisely.

This "pancaking" is/was a metaphor for spreading out radially in all direction - such that the diameter of the annular ring of westerlies around the northern hemisphere increases. In order to do so requires the latitude of the westerlies to come south, because of the geometry of a sphere of course...

The reason why this pancaking happens is because the actual geopotential height, which is the same as geometric height but expressed in the form of

is derived by considering temperature as one of the variable in the precursor equation, where increasing heights then implies rising temperatures aloft (sparing you the derivation).

The simple model above is thus taking place at very large scales, and doing so amid the perpetual atmospheric motion. The same downward vertical motion, a term referred to as subsidence, is occurring in positive flux, and when it reaches the ground, mass conservation then forces more northerly component to the wind field in the lower troposphere. This, of course, is not happening everywhere at all times. In fact, -AO/-NAO have attending correlations for warmer than normal at certain teleconnection

points around the hemisphere - but by and large the middle latitudes will find more negative anomaly temperature points than positive during -AO, and more importantly for us here in the U.S. and wester Europe when the NAO is negative.

John

[Typhoon Tip]

Wow - did the 18z GFS underscore that risk I was discussing regarding stream phasing in this type of regime! 200 hours out is red herring, but man that is a great example of pv bifurcation and subsequent subsuming of an intermediate stream along the MA.

oy vei, it has to be 200 hours out

[Typhoon Tip]

gee what gorgeous solution that is, too - you'd be talking 18" from interior VA to Maine

[skierinvermont]

This is a good point about Volcanism - I chose not to include it because in all honesty the effects of volcanic aerosols in the stratosphere, although known, I personally am less versed in that area of geo-sciences. My very basic understanding is that increased SO2 particulate matter is a cooling factor due to literally reflecting some fragment of the total solar budge back out into space before it has a chance to be absorbed and then transferred to kinetic temperature. That's as far as my understanding goes, and I am not really sure of residence (time it takes to cleanse), or what the volcano numbers were during the summer and autumn. As far as I am away Iceland's system has quieted down over the last several months.

None of the volcanoes this year were large enough to have a significant influence on global temperature. Not even close. You need large amounts of SO2 to be released into the stratosphere .. these volcanoes this year either released none into the stratosphere, or released quantities which were orders of magnitude too small to have an effect. The highest the ash made it was to the upper troposphere during the Iceland and Merapi eruptions (a relatively small cloud of ash was observed at the height of the Merapi eruption at 40-50k feet, in the upper troposphere). Pinatubo, by comparison ejected 17 million tons of SO2 directly into the stratosphere.

I think I have heard that the SO2 and/or aerosols released into the troposphere can affect things like the AO or NAO though. That's a possibility. But as for affecting global temperature.. it takes volcanoes 1 or 2 orders of magnitude larger than those we have seen this year, such as Pinatubo or El Chichon.

[Amped]

I don't really see a 1 or 2 wave pattern here usually favorable for warmings. It's more of a starfish pattern until yeo get above the 10MB level where it becomes a big Oval

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ec.php?alert=1&level=10&forecast=f168&lng=eng