Possible Snow Gradient Explanation

[ORH_wxman]

I should add though: if your interest is just in the Aleutian High, I shouldn't have left 73-74 out. If your interest is in the New England snowfall gradient, I think it might have been wise to leave it out. The 73-74 La Nina was the strongest ever recorded. The entire state of the oceans were very cold and the Gulf of Alaska was also colder than normal. The warm anomaly associated with the -PDO was shunted well south/west. All of this combined lead to a very displaced Hadley/Walker circulation (west) and therefore a more displaced Aleutian Ridge.

The more west ridge allowed for more of a Southeast Ridge to develop. So, I am sure 73-74 was probably a good gradient year because the general circulation across the CONUS mimicked a -QBO La Nina.

But the deep-westerly QBO connection still holds to a more poleward Aleutian High, even in the strongest La Nina.

Yeah in the interest of the original premise for this thread (snowfall gradients near/in New England), '73-'74 is actually an interesting case. It had a gradient, but it was much more SE to NW than the usual N/S gradient. The SE ridge was quite robust that year and displaced further west than normal which might explain why the gradient was tilted. NW New England up by BTV had a huge winter while further east into Maine it was pretty cruddy.

[ORH_wxman]

Nice block in NE Canada, would yield some pretty good Arctic outbreaks I would think especially in the Upper Midwest. Do not like the -PNA look but with a block set up the opportunity for a good gradient winter apperas to be on track. The classic 70-71 gradient appearing as an analog again this year is interesting. A midwinter warming event would be just what the DR ordered.

-PNA is tough to avoid when you have a robust Aleution high....unless its displaced well to the northeast. By definition, the PNA is measuring the height anomalies south of the Aleutians and the height anomalies in western Canada.

[Ginx snewx]

-PNA is tough to avoid when you have a robust Aleution high....unless its displaced well to the northeast. By definition, the PNA is measuring the height anomalies south of the Aleutians and the height anomalies in western Canada.

I believe our 70-71 winter was primarily dominated by a - PNA? Kind of a roll over ridge situation with the block in E Canada allowing arctic intrusions along with some sturdy coastals.

[HM]

Yeah in the interest of the original premise for this thread (snowfall gradients near/in New England), '73-'74 is actually an interesting case. It had a gradient, but it was much more SE to NW than the usual N/S gradient. The SE ridge was quite robust that year and displaced further west than normal which might explain why the gradient was tilted. NW New England up by BTV had a huge winter while further east into Maine it was pretty cruddy.

Yeah that was an exceptional year of atmospheric players. It would have probably ended up just like the 55-56 winter, too, if either the La Nina was a tad weaker and/or the PDO warm anomaly was more robust/further NE. But, this is why you have to look at more than 1 thing and play everything out.

[Ginx snewx]

Michigan sure loved 1971 winter, nice memories for the older crowd

[ORH_wxman]

I believe our 70-71 winter was primarily dominated by a - PNA? Kind of a roll over ridge situation with the block in E Canada allowing arctic intrusions along with some sturdy coastals.

Last winter was primarily a -PNA, but the northward extent of the Aleutian high and the extreme blocking in Greenland the first 6-7 weeks helped make it a very cold winter anyway for the east. What also helped is that when the blocking in the Atlantic finally broke down, we had an MJO-induced +PNA for a brief 10-15 day period in the 2nd half of January to keep things cold in the east.

We mentioned a few times earlier in the thread (or it might have been the winter 2011-2012 thread in NE forum) how the MJO can throw off a monthly forecast if its active enough to get robust convection to the dateline region. There's a pretty good chance that we see a mean -PNA this winter, however, as we saw last winter, an MJO wave timed well in January or something can produce a very different look for a brief time and produce some winter storm threats for all of the east...not just the northern tier.

[usedtobe]

Last winter was primarily a -PNA, but the northward extent of the Aleutian high and the extreme blocking in Greenland the first 6-7 weeks helped make it a very cold winter anyway for the east. What also helped is that when the blocking in the Atlantic finally broke down, we had an MJO-induced +PNA for a brief 10-15 day period in the 2nd half of January to keep things cold in the east.

We mentioned a few times earlier in the thread (or it might have been the winter 2011-2012 thread in NE forum) how the MJO can throw off a monthly forecast if its active enough to get robust convection to the dateline region. There's a pretty good chance that we see a mean -PNA this winter, however, as we saw last winter, an MJO wave timed well in January or something can produce a very different look for a brief time and produce some winter storm threats for all of the east...not just the northern tier.

I guess that was part of my point and question. How does the QBO impact the MJO. AN easterly phase of the former seems to bring convection towards stage 8 is that because of the mjo and deeper convection or is it because of the QBO? or can you separate the two?

[ORH_wxman]

I guess that was part of my point and question. How does the QBO impact the MJO. AN easterly phase of the former seems to bring convection towards stage 8 is that because of the mjo and deeper convection or is it because of the QBO? or can you separate the two?

I am probably the wrong person to ask about the QBO/MJO relationship. I don't think I could answer it very well. Ironically, the recent Nina winters that have had a +QBO were the ones that saw strong MJO waves into phase 7/8....that would be last winter and 2008-2009. The -QBO/Nina winters saw the MJO waves weaken rapidly as they approached phase 8 ('05-'06 and '07-'08).

This is just recent years and only for Ninas. We certainly have seen a ton of convection near the dateline in El Nino/-QBO years...2009-2010 being a great example. I'm not sure on the exact forcing mechanisms though.

[usedtobe]

I am probably the wrong person to ask about the QBO/MJO relationship. I don't think I could answer it very well. Ironically, the recent Nina winters that have had a +QBO were the ones that saw strong MJO waves into phase 7/8....that would be last winter and 2008-2009. The -QBO/Nina winters saw the MJO waves weaken rapidly as they approached phase 8 ('05-'06 and '07-'08).

This is just recent years and only for Ninas. We certainly have seen a ton of convection near the dateline in El Nino/-QBO years...2009-2010 being a great example. I'm not sure on the exact forcing mechanisms though.

Will,

Your observations about recent QBO plus years is at odds with the Geller article (I think). Here's the abstract

Abstract

Some recent papers (both observational and modeling analyses) have indicated that the stratospheric quasi-biennial oscillation (QBO) significantly affects the troposphere. Some of the difficulties in these observational studies are properly separating El Niño/Southern Oscillation (ENSO) from QBO influences and some ambiguities in the indicators of tropical deep convection. In this paper, we try to improve on these aspects. We use 21.5 years of detailed tropical Weather State (WS) information from the International Satellite Cloud Climatology Project (ISCCP) to describe an influence of the QBO on tropical deep convection and cirrus clouds. Correlations between monthly indices for the QBO and indices for ENSO, Tropospheric Biennial Oscillation (TBO), and the Pacific Decadal Oscillation (PDO) are taken into account. While tropical deep convection is mostly related to ENSO and the annual cycle, the QBO, independent of ENSO, leads to significantly increased deep convection in the Tropics between 150 and 180 oE as well as over the Subtropics around 120 oW. Cirrus clouds over the Tropical West Indian Ocean and West Atlantic are also increased during the easterly QBO phase. Deep convection between 60 and 90 oE as well as over the Central and East Pacific and over central Australia is significantly reduced. The observed pattern reveals a westward (eastward) shift in the strength of the meridional overturning contributions to the Hadley circulation over the Pacific related to the downward influence of the easterly (westerly) QBO.

http://adsabs.harvard.edu/abs/2009AGUFM.A51H0213G

The qbo abstract and the mjo that noted when the tropical forcing gets into the Pacific that it might precondition the atmosphere towards a negative nao made me wonder since if you composite neg nao years you end up with with OLR minimum along the tropical central pacific and a min during strongly positive nao years. I think either you VAWxman did the original composites. I have them stashed somewhere.

[CoastalWx]

Will,

Your observations about recent QBO plus years is at odds with the Geller article (I think). Here's the abstract

Abstract

Some recent papers (both observational and modeling analyses) have indicated that the stratospheric quasi-biennial oscillation (QBO) significantly affects the troposphere. Some of the difficulties in these observational studies are properly separating El Niño/Southern Oscillation (ENSO) from QBO influences and some ambiguities in the indicators of tropical deep convection. In this paper, we try to improve on these aspects. We use 21.5 years of detailed tropical Weather State (WS) information from the International Satellite Cloud Climatology Project (ISCCP) to describe an influence of the QBO on tropical deep convection and cirrus clouds. Correlations between monthly indices for the QBO and indices for ENSO, Tropospheric Biennial Oscillation (TBO), and the Pacific Decadal Oscillation (PDO) are taken into account. While tropical deep convection is mostly related to ENSO and the annual cycle, the QBO, independent of ENSO, leads to significantly increased deep convection in the Tropics between 150 and 180 oE as well as over the Subtropics around 120 oW. Cirrus clouds over the Tropical West Indian Ocean and West Atlantic are also increased during the easterly QBO phase. Deep convection between 60 and 90 oE as well as over the Central and East Pacific and over central Australia is significantly reduced. The observed pattern reveals a westward (eastward) shift in the strength of the meridional overturning contributions to the Hadley circulation over the Pacific related to the downward influence of the easterly (westerly) QBO.

http://adsabs.harvar...AGUFM.A51H0213G

The qbo abstract and the mjo that noted when the tropical forcing gets into the Pacific that it might precondition the atmosphere towards a negative nao made me wonder since if you composite neg nao years you end up with with OLR minimum along the tropical central pacific and a min during strongly positive nao years. I think either you VAWxman did the original composites. I have them stashed somewhere.

The whole thing is a little confusing because it is thought that the west phase of the QBO enhances tropical activity in the Atlantic basin while the east phase possibly may do the opposite. I know this is the Atlantic basin that this article is talking about, but I figured it applied to the subtropical latitudes. At first glance is seems to go against the articles you referenced, but I admit I didn't read them too carefully yet. Perhaps it is also because we truly don't have a firm grasp on this stuff yet.

http://www.aoml.noaa.gov/hrd/Landsea/atlantic/index.html.

[usedtobe]

The whole thing is a little confusing because it is thought that the west phase of the QBO enhances tropical activity in the Atlantic basin while the east phase possibly may do the opposite. I know this is the Atlantic basin that this article is talking about, but I figured it applied to the subtropical latitudes. At first glance is seems to go against the articles you referenced, but I admit I didn't read them too carefully yet. Perhaps it is also because we truly don't have a firm grasp on this stuff yet.

http://www.aoml.noaa...ntic/index.html.

I think the QBO acts differently somewhat during summer versus other seasons. This abstract implies it. I've bolded the important part.

Abstract

The height and amount of tropical deep convection are examined for a correlation with the stratospheric quasi-biennial oscillation (QBO). A new 23-yr record of outgoing longwave radiation (OLR) and a corrected 17-yr record of the highly reflective cloud (HRC) index are used as measures of convection. When binned by phase of the QBO, zonal means and maps of OLR and HRC carry a QBO signal. The spatial patterns of the maps highlight the QBO signal of OLR and HRC in typically convective regions. Spectral analysis of zonal mean OLR and HRC near the equator reveals significant peaks at QBO frequencies. Rotated empirical orthogonal function (REOF) analysis is used to determine if ENSO variations of convection are aliased into the observed QBO signals. Some analyses are repeated using the OLR record after ENSO REOF modes have been removed, yielding very similar results compared to the original analyses. It appears that the QBO signal is distinct from the ENSO signal, although the relative brevity of the OLR and HRC records with respect to the ENSO cycle makes assessing the impact of ENSO difficult.Three mechanisms that can link the QBO with deep convection are investigated: 1) the QBO modulation of tropopause height may allow convection to penetrate deeper in some years compared to other years; 2) the QBO modulation of lower-stratospheric to upper-tropospheric zonal wind shear may result in cloud tops being `sheared off' more in some years than in other years; 3) the QBO modulation of upper-tropospheric relative vorticity may relax dynamic constraints on cloud-top outflow and thus allow more cloud growth in some years compared to other years. Measures of these mechanisms-tropopause pressure and temperature, 50-200-hPa zonal wind shear (cross-tropopause shear), and 150-hPa vorticity, all from the NCEP reanalyses-are compared to OLR and HRC. QBO fluctuations of convection are generally well correlated with QBO fluctuations of tropopause height. In regions where these height fluctuations are relatively small, convective fluctuations are well correlated with QBO variations of cross-tropopause shear, especially during boreal summer and winter when convection is concentrated away from the equator and the largest tropopause height fluctuations. In fact, during summer the shear mechanism appears to dominate such that QBO-related convective behavior is different than during the other seasons. QBO convective behavior is uncorrelated with vorticity fluctuations near the tropopause.A secondary component of this study is the description of a new, long-term OLR dataset. Using measurements from Nimbus-6, Nimbus-7, and the Earth Radiation Budget Satellite (ERBS), the 23-yr OLR record analyzed in this study was constructed. This record has fewer interannual biases due to satellite differences than the well-known NOAA OLR record and, therefore, is more useful for studies of interannual meteorological variations.

I also thought that the reason that a easterly qbo year was more likely to have blocking was due to the deeper convection in the Pacific which makes it more likely that to get stratospheric warming events earlier in the season. The idea that convection in the mid Pacific might impact the stratosphere and lead to downwelling at high latitudes is illustrated by the figure below. The reason I broought this all up was related to the increased potential for the NAM to play a role sometime this winter for awhile with a possible weakening of the polar vortex. That would suggest at least a month or so with a negative AO along with a possible La Nina which would have implications towards the snow gradient across the northeast and mid atlantic region. I was hoping HM or someone else with more knowledge than me on the subject would weigh in. I'm in the same boat as you in my understanding of the QBO and its impact on the pattern.

[tamarack]

Yeah in the interest of the original premise for this thread (snowfall gradients near/in New England), '73-'74 is actually an interesting case. It had a gradient, but it was much more SE to NW than the usual N/S gradient. The SE ridge was quite robust that year and displaced further west than normal which might explain why the gradient was tilted. NW New England up by BTV had a huge winter while further east into Maine it was pretty cruddy.

Understatement, IMO. That was my 1st full winter in Maine, and it was a disappointment. BGR had less snow than I'd been averaging in NNJ - would've been about half the Jersey avg except for the 9" storm (and two smaller ones) in April. In mid-Dec, while BTV had big snow and W.CT was hammered by their worst ice storm, BGR was a mid-50s downpour (and my folks back in NNJ had a temp 40F colder than I did at the same time in Bangor.)

[CoastalWx]

I think the QBO acts differently somewhat during summer versus other seasons. This abstract implies it. I've bolded the important part.

Abstract

The height and amount of tropical deep convection are examined for a correlation with the stratospheric quasi-biennial oscillation (QBO). A new 23-yr record of outgoing longwave radiation (OLR) and a corrected 17-yr record of the highly reflective cloud (HRC) index are used as measures of convection. When binned by phase of the QBO, zonal means and maps of OLR and HRC carry a QBO signal. The spatial patterns of the maps highlight the QBO signal of OLR and HRC in typically convective regions. Spectral analysis of zonal mean OLR and HRC near the equator reveals significant peaks at QBO frequencies. Rotated empirical orthogonal function (REOF) analysis is used to determine if ENSO variations of convection are aliased into the observed QBO signals. Some analyses are repeated using the OLR record after ENSO REOF modes have been removed, yielding very similar results compared to the original analyses. It appears that the QBO signal is distinct from the ENSO signal, although the relative brevity of the OLR and HRC records with respect to the ENSO cycle makes assessing the impact of ENSO difficult.Three mechanisms that can link the QBO with deep convection are investigated: 1) the QBO modulation of tropopause height may allow convection to penetrate deeper in some years compared to other years; 2) the QBO modulation of lower-stratospheric to upper-tropospheric zonal wind shear may result in cloud tops being `sheared off' more in some years than in other years; 3) the QBO modulation of upper-tropospheric relative vorticity may relax dynamic constraints on cloud-top outflow and thus allow more cloud growth in some years compared to other years. Measures of these mechanisms-tropopause pressure and temperature, 50-200-hPa zonal wind shear (cross-tropopause shear), and 150-hPa vorticity, all from the NCEP reanalyses-are compared to OLR and HRC. QBO fluctuations of convection are generally well correlated with QBO fluctuations of tropopause height. In regions where these height fluctuations are relatively small, convective fluctuations are well correlated with QBO variations of cross-tropopause shear, especially during boreal summer and winter when convection is concentrated away from the equator and the largest tropopause height fluctuations. In fact, during summer the shear mechanism appears to dominate such that QBO-related convective behavior is different than during the other seasons. QBO convective behavior is uncorrelated with vorticity fluctuations near the tropopause.A secondary component of this study is the description of a new, long-term OLR dataset. Using measurements from Nimbus-6, Nimbus-7, and the Earth Radiation Budget Satellite (ERBS), the 23-yr OLR record analyzed in this study was constructed. This record has fewer interannual biases due to satellite differences than the well-known NOAA OLR record and, therefore, is more useful for studies of interannual meteorological variations.

I also thought that the reason that a easterly qbo year was more likely to have blocking was due to the deeper convection in the Pacific which makes it more likely that to get stratospheric warming events earlier in the season. The idea that convection in the mid Pacific might impact the stratosphere and lead to downwelling at high latitudes is illustrated by the figure below. The reason I broought this all up was related to the increased potential for the NAM to play a role sometime this winter for awhile with a possible weakening of the polar vortex. That would suggest at least a month or so with a negative AO along with a possible La Nina which would have implications towards the snow gradient across the northeast and mid atlantic region. I was hoping HM or someone else with more knowledge than me on the subject would weigh in. I'm in the same boat as you in my understanding of the QBO and its impact on the pattern.

Alright, well that makes sense with the seasonal variability. I was thinking that might play a role...and makes sense that it would.

[Snowstorms]

Great explanation on the QBO HM and its correlation with Winter Temperatures/Jet streams and such and more importantly the Atmospheric state during each of its phases. I've got only one question. You said a -QBO weakens the Aleutian High which is correlated well with a -PDO phase and often a -PNA phase but if we saw a similar Blocking pattern to that of 89 across the Pacific would it affect the QBO in any general way which would then affect the NAO/AO and NAM index as a result since the QBO is a stratospheric phenomena and such.

Does the QBO like the ENSO affect the Subtropical Jet stream flow. I know that it has an effect on the Polar Jet and PV placement but it seems logical enough that it may effect the STJ.

[HM]

Great explanation on the QBO HM and its correlation with Winter Temperatures/Jet streams and such and more importantly the Atmospheric state during each of its phases. I've got only one question. You said a -QBO weakens the Aleutian High which is correlated well with a -PDO phase and often a -PNA phase but if we saw a similar Blocking pattern to that of 89 across the Pacific would it affect the QBO in any general way which would then affect the NAO/AO and NAM index as a result since the QBO is a stratospheric phenomena and such.

Does the QBO like the ENSO affect the Subtropical Jet stream flow. I know that it has an effect on the Polar Jet and PV placement but it seems logical enough that it may effect the STJ.

I've got to be honest, I had to read this several times to understand your question and I am not sure if I did. Are you asking me if the QBO can be affected by low-level parameters (anything tropospheric/terrestrial) ?

Yes, the QBO and ENSO both affect the Hadley Cell which affects the STJ.

[HM]

I also thought that the reason that a easterly qbo year was more likely to have blocking was due to the deeper convection in the Pacific which makes it more likely that to get stratospheric warming events earlier in the season. The idea that convection in the mid Pacific might impact the stratosphere and lead to downwelling at high latitudes is illustrated by the figure below. The reason I broought this all up was related to the increased potential for the NAM to play a role sometime this winter for awhile with a possible weakening of the polar vortex. That would suggest at least a month or so with a negative AO along with a possible La Nina which would have implications towards the snow gradient across the northeast and mid atlantic region. I was hoping HM or someone else with more knowledge than me on the subject would weigh in. I'm in the same boat as you in my understanding of the QBO and its impact on the pattern.

The -QBO's effect on the Brewer-Dobson Circulation starts in the autumn and it takes roughly 3-6 months for that ozone to make it to the North Pole; but in a year like this one, this isn't going to work out so well. The QBO affects the polar vortex through planetary wave behavior more so than the convection. There is more to how the BDC/NAM/PV behave than what the QBO state dictates and the same can be said about tropical forcing. Yes, the theory is that -QBO increases equatorial convection with a higher than normal tropopause, particularly in the western Pacific. However, this doesn't necessarily mean MJO waves either and this entire process is always augmented by ENSO. Don't forget, the sun also plays a role in tropical convection through changes in incoming radiation and temperature.

But this thread's main point was to discuss how the tropical Pacific may affect the z-circulations which would affect the Aleutian High. These relationships cannot be applied to tropical convection because many things can cause a MJO wave. For example, the late stratospheric warming of intense magnitude this year displaced cooler air into the equatorial regions and caused big time MJO waves to develop (along with warming ENSO). In fact, we have been riding those harmonics ever since in a much weakened state. As of right now, the +QBO is in full control of the lower stratosphere and has generally been keeping tropical forcing weak, in terms of waves, but enhancing areas off the equator for sure. This would likely continue through the autumn season, except that off-equatorial convection would gradually weaken with time. A heavily ENSO-dominated period would likely be in the end-result along with a more expanded than normal Hadley Cell.

[OKpowdah]

The whole thing is a little confusing because it is thought that the west phase of the QBO enhances tropical activity in the Atlantic basin while the east phase possibly may do the opposite. I know this is the Atlantic basin that this article is talking about, but I figured it applied to the subtropical latitudes. At first glance is seems to go against the articles you referenced, but I admit I didn't read them too carefully yet. Perhaps it is also because we truly don't have a firm grasp on this stuff yet.

http://www.aoml.noaa...ntic/index.html.

Basically, an easterly QBO implies a colder stratosphere, and raised tropopause over the equator, and warmer off the equator (~10-15 degrees). Opposite for westerly QBO. So an easterly QBO I would think would tend to increase MJO activity. There are some other factors associated with PV and cross tropopause shear, but I think that tropopause height has the greatest association to convection patterns.

[HM]

Basically, an easterly QBO implies a colder stratosphere, and raised tropopause over the equator, and warmer off the equator (~10-15 degrees). Opposite for westerly QBO. So an easterly QBO I would think would tend to increase MJO activity. There are some other factors associated with PV and cross tropopause shear, but I think that tropopause height has the greatest association to convection patterns.

But, let's say a +QBO was occurring and helped to suppress overall convection. Wouldn't this increase the chances for MJO activity if we could help dampen stagnant ENSO forcing?

My point is: there are so many different ways to get MJO activity and I don't think we can easily favor it or not based on the QBO alone. It just isn't that simple. I think part of the problem is that we are still at the infancy of understanding the MJO (which hopefully sees an advancement this winter with the research project). The other part has to do with how broad of a system the QBO is and how many different vertical and horizontal circulations get affected by it.

Right now, I would say things are "textbook" for a downwelling +QBO wave this time of year. But they certainly weren't early in the cold season and late in the cold season because the North Pole dictated the temperatures across the Tropics during those periods. We saw decent MJO activity in the +QBO years of 80-81, especially March. Then we got to the 81-82 winter with a -QBO and the MJO dropped off significantly. While the temperatures are significant and the QBO relationship is important, I just don't want people saying that a -QBO causes this and that's the end of it. It is way more complicated.

[Snowstorms]

I've got to be honest, I had to read this several times to understand your question and I am not sure if I did. Are you asking me if the QBO can be affected by low-level parameters (anything tropospheric/terrestrial) ?

Yes, the QBO and ENSO both affect the Hadley Cell which affects the STJ.

Its alright. I guess I should have implied the question in a better term.

What I'm asking is that with the -QBO could it imply a similar blocking pattern across the Pacific like in 89? For example, during a -QBO (-PDO/-ENSO phase) we often have a very strong Aleutian High which can sometimes suppress the jet stream further south across the West and create a ridge across the East further strengthening the SE Ridge's effects and so forth.

And we know in the Hadley cell the wind anomalies move further north but thanks to the Coriolis effect the Winds turn left in the SH and right in the NH and this effects the Jet streams including the Subtropical Jet and during Nino's the STJ is displaced further north creating Wind shear across the Atlantic.

But yes can the QBO effect the Jet stream (Polar Jet./Subtropical Jet) and can this further impact the storm intensity and track?

Does the effect of the QBO depend on the ENSO strength or not?

[CoastalWx]

Basically, an easterly QBO implies a colder stratosphere, and raised tropopause over the equator, and warmer off the equator (~10-15 degrees). Opposite for westerly QBO. So an easterly QBO I would think would tend to increase MJO activity. There are some other factors associated with PV and cross tropopause shear, but I think that tropopause height has the greatest association to convection patterns.

I wonder though how much of an effect this has. I mean tropopause heights in this area are so high to begin with..how much more could this theory help out? I suppose if this somehow enhances subsidence or the subtropical high to help sustain subsidence then it may help, but HM is probably right in that so many things influence the MJO. Such a complicated feature.

[HM]

Its alright. I guess I should have implied the question in a better term.

What I'm asking is that with the -QBO could it imply a similar blocking pattern across the Pacific like in 89? For example, during a -QBO (-PDO/-ENSO phase) we often have a very strong Aleutian High which can sometimes suppress the jet stream further south across the West and create a ridge across the East further strengthening the SE Ridge's effects and so forth.

And we know in the Hadley cell the wind anomalies move further north but thanks to the Coriolis effect the Winds turn left in the SH and right in the NH and this effects the Jet streams including the Subtropical Jet and during Nino's the STJ is displaced further north creating Wind shear across the Atlantic.

But yes can the QBO effect the Jet stream (Polar Jet./Subtropical Jet) and can this further impact the storm intensity and track?

Does the effect of the QBO depend on the ENSO strength or not?

There just isn't cut and dry rules for how all of these things tie together. I know this sounds like a bit of a cop out but it is the most responsible thing I can answer you with. The QBO can directly and indirectly affect the jet stream through either planetary wave behavior, tropical forcing behavior or combining with other parameters to affect circulation. In the case of what was presented in this thread, it appeared as if the zonal wind behavior was directly responsible for the placement of major circulations across the Pacific between my La Nina-east and La Nina-west years.

The +QBO coupled with La Nina tends to significantly warm the equatorial stratosphere and this allows the Hadley Cell to expand poleward, simply because off-equatorial convection is dominate. This seemed to help shift all major North Pacific circulations poleward as well. Also, throw in the fact that lower stratospheric winds spin anticyclonic, with a mean westerly equatorial wind, across the Aleutians (tighter mid latitude easterlies and stronger polar vortex allow for this) and you seem to have a good case for why a +QBO during cold ENSO would favor an Aleutian High more poleward.

[HM]

I wonder though how much of an effect this has. I mean tropopause heights in this area are so high to begin with..how much more could this theory help out? I suppose if this somehow enhances subsidence or the subtropical high to help sustain subsidence then it may help, but HM is probably right in that so many things influence the MJO. Such a complicated feature.

The real question is: how will the state of the QBO, sun and ENSO (to name a few) affect the Walker and Hadley Cells? It is then and only then when you can start to make an argument about how the MJO might behave this cold season. You just can't say -QBO= active MJO or -QBO=dateline convection.

[OKpowdah]

But, let's say a +QBO was occurring and helped to suppress overall convection. Wouldn't this increase the chances for MJO activity if we could help dampen stagnant ENSO forcing?

My point is: there are so many different ways to get MJO activity and I don't think we can easily favor it or not based on the QBO alone. It just isn't that simple. I think part of the problem is that we are still at the infancy of understanding the MJO (which hopefully sees an advancement this winter with the research project). The other part has to do with how broad of a system the QBO is and how many different vertical and horizontal circulations get affected by it.

Right now, I would say things are "textbook" for a downwelling +QBO wave this time of year. But they certainly weren't early in the cold season and late in the cold season because the North Pole dictated the temperatures across the Tropics during those periods. We saw decent MJO activity in the +QBO years of 80-81, especially March. Then we got to the 81-82 winter with a -QBO and the MJO dropped off significantly. While the temperatures are significant and the QBO relationship is important, I just don't want people saying that a -QBO causes this and that's the end of it. It is way more complicated.

Yeah, that's a pretty good point. What's the research project on the MJO?

[Snowstorms]

There just isn't cut and dry rules for how all of these things tie together. I know this sounds like a bit of a cop out but it is the most responsible thing I can answer you with. The QBO can directly and indirectly affect the jet stream through either planetary wave behavior, tropical forcing behavior or combining with other parameters to affect circulation. In the case of what was presented in this thread, it appeared as if the zonal wind behavior was directly responsible for the placement of major circulations across the Pacific between my La Nina-east and La Nina-west years.

The +QBO coupled with La Nina tends to significantly warm the equatorial stratosphere and this allows the Hadley Cell to expand poleward, simply because off-equatorial convection is dominate. This seemed to help shift all major North Pacific circulations poleward as well. Also, throw in the fact that lower stratospheric winds spin anticyclonic, with a mean westerly equatorial wind, across the Aleutians (tighter mid latitude easterlies and stronger polar vortex allow for this) and you seem to have a good case for why a +QBO during cold ENSO would favor an Aleutian High more poleward.

The QBO I know isn't the only natural forcing out there influencing climate and weather but it can effect certain weather phenomenas including wind anomalies and stratospheric/tropospheric temperatures.

Anyways thanks for your reply

Also I've noticed the current MJO wave moving towards phase 6/7 which wouldn't be so great for the La Nina and could this and the QBO be linked? Thanks! Despite that, the trade winds are still in control.

[HM]

Yeah, that's a pretty good point. What's the research project on the MJO?

Check it out: http://www.eol.ucar.edu/projects/dynamo/documents/WP_latest.pdf

[OKpowdah]

I wonder though how much of an effect this has. I mean tropopause heights in this area are so high to begin with..how much more could this theory help out? I suppose if this somehow enhances subsidence or the subtropical high to help sustain subsidence then it may help, but HM is probably right in that so many things influence the MJO. Such a complicated feature.

No idea how worthwhile the effect is. But it has worked for a few of my ideas in the past. If you raise the tropopause at the equator and lower it off equator, you'll naturally get a z circulation superimposed on the environment, with rising over the equator. But yeah, HM has a good point with the uncertainties of the MJO

[OKpowdah]

Check it out: http://www.eol.ucar....s/WP_latest.pdf

Cool thanks!!

[CoastalWx]

The real question is: how will the state of the QBO, sun and ENSO (to name a few) affect the Walker and Hadley Cells? It is then and only then when you can start to make an argument about how the MJO might behave this cold season. You just can't say -QBO= active MJO or -QBO=dateline convection.

Yep, so true with various things in meteorology. This topic (mostly QBO) is something that I don't have a complete understanding of, but I think it's a good topic for mets and the general weather enthusiast community to discuss.

[Typhoon Tip]

Check it out: http://www.eol.ucar....s/WP_latest.pdf

I always thought it would be fascinating if there was a connection discovered between mid latitude wave frequency/magnitude as passing near/over the Teb. Plateau area serving as a trigger of sort.

One thing about the MJO that I have personally noticed over the years is that it seems to susceptible to larger scale environmental feed-backs. If the Pac region (WPO) status is opposing the longer term correlation, the MJO seems to propagate along weaker. What would be interesting is whether the WPO/MJO relationship had any meaningful correlation on the downstream whole-scale circulation.

[HM]

I always thought it would be fascinating if there was a connection discovered between mid latitude wave frequency/magnitude as passing near/over the Teb. Plateau area serving as a trigger of sort.

One thing about the MJO that I have personally noticed over the years is that it seems to susceptible to larger scale environmental feed-backs. If the Pac region (WPO) status is opposing the longer term correlation, the MJO seems to propagate along weaker. What would be interesting is whether the WPO/MJO relationship had any meaningful correlation on the downstream whole-scale circulation.

I haven't run anything statistical between the MJO and WPO but I would imagine that the WPO variability is caused by the MJO and not the other way around. Although, like anything in weather, there is always a way something can affect something the other way too. And I do agree that there is a feedback between the mid latitudes and the MJO as well as the poles/stratosphere too. The positive WPO phase is a classic poleward shifted Hadley Cell, typical of a MJO progression from Indonesia through the Tropical Pacific (like phase 4-7).