Re: Long Range Thread 12.0

[algae888]

Wow, looks like travel during Thanksgiving week is going to be rough....

[algae888]

nice! when was the last time we saw this in dec. days upon days of a -nao on gefs and for several runs now. pac looks better too!

there are times when a block sets up it's hard to break. really would be great to get winter off to an early start.

[algae888]

from jb...euro through dec 30th

[Frank_Wx]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

[weatherwatchermom]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

are you talking possible snow storm?

[rb924119]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

I don't know man, I still think it may end up being more transient than full-fledged. I hope not, but even though we are seeing the insane Greenland block and the negative AO, I just do not like the look of the stratosphere and the Pacific. Looking at the whole setup, we look to be centered west of the time-mean trough axis, which does not bode well for white gold action :/

[Math23x7]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

DT mentioned that as impressive as the EURO weeklies look for cold in the Eastern US, until he sees the Pacific Jet weaken, he will be very skeptical about it.

[algae888]

The aam is forecast to weaken. If it does will this alone be able to slow down the pac jet?

[Frank_Wx]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

I don't know man, I still think it may end up being more transient than full-fledged. I hope not, but even though we are seeing the insane Greenland block and the negative AO, I just do not like the look of the stratosphere and the Pacific. Looking at the whole setup, we look to be centered west of the time-mean trough axis, which does not bode well for white gold action :/

Stratosphere looks amazing considering the time of year. It's actually the one bright variable. Please elaborate?

[Frank_Wx]

Models are showing a possible wintry event, especially N&W of NYC on Thanksgiving Day.

[Frank_Wx]

Also, I'm not buying a full fledged pattern change yet either but transient shots of cold this time of year could produce as long as timing is favorable

[sroc4]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

I don't know man, I still think it may end up being more transient than full-fledged. I hope not, but even though we are seeing the insane Greenland block and the negative AO, I just do not like the look of the stratosphere and the Pacific. Looking at the whole setup, we look to be centered west of the time-mean trough axis, which does not bode well for white gold action :/

Stratosphere looks amazing considering the time of year. It's actually the one bright variable. Please elaborate?

I cant speak for Ray but I am more concerned with positioning regarding the strat.  Its no coincidence that the coldest air in the N hemisphere has been on the wrong side of the globe.  If you actually look at the distribution of the 850 temps and anomalies the coldest locations and the 0*C line pretty much line up with the lower strat circulation(70mb) since the beginning of Nov. And the two coldest spots line up nicely with where the centers of the 70mb vortex is as wll as where the 10mb elongated center is situated over top.  Here it is currently:






Although the Strat vortex is forecast to remain weak and a second warming event toward the end of this month or early next month looks possible, the forecast is for it to remain centered on the other side of the N Hemisphere, at least for the foreseeable future. I worry that the downward press from a warm strat leads to the heights lowering more consistently in the same locations as now. Not impossible to get our cold shots into NA but more difficult and more short lived when combined with the concerns in the N Pac.

Here is the 240hr Euro strat forecast location from yesterday:  


 I worry that this will cont to keep the coldest air locked up in asia, and although provide some high latitude blocking it may not allow for a true cross polar flow.  Combine that with concerns in the N Pac.

Yeah I know the AAM is forecast to change which in theory is historically conducive to disrupting the strong N pac jet, but 1) If the current SSTA configuration in the C and N Pac holds strong, which I cant see it changing any time soon despite what may appear like a classive +PDO look around the NE Pac it may not be enough.  and 2) with the extremely cold air in E Asia and the warm waters/SSTA gradient well stablished in the Pac large scale baroclinic enhancement of the Pac jet between E Asia dna the E IO/Indonesia region will remain firmly in place.  This is actually something noted by J Cohan in his latest update:

"On the other hand the North Pacific jet looks to remain highly energetic.  The more energized jet seems to be a response to the very cold temperatures across Siberia and an increased equator to pole temperature gradient.  With no sign of moderating temperatures across Siberia I see little reason to anticipate a slackening of the North Pacific Jet.  A strong North Pacific Jet crossing the West Coast of North America often results in a mild to very mild pattern across the continent and this remains a strong possibility.  However, I wrote last week that I expect a southward displaced North Pacific Jet and for now the models agree."

For me I worry that any disruption for the better to the strong N Pac jet ends up being transient, (a week a month who knows) because of the SSTA and an unfavorable strat position; combine that with an equatorial walker and hadley cell configuration that has persistently behaved in a L Nina fashion as seen by the persistent OLR maps.  When or if the current MJO quiets down will we once again see stronger energy transfer out of the unfavorable MJO phases 4-5-6 again which again would only aid in the enhancement of a stronger N Pac jet?  The almost coast to coast horizontal SSTA configuration in the central and N Pac(warm cold warm from N to S), weak La Nina across the trop Pac combined with the exceptional cold in E Asia and the warm waters located due south around the E IO and Indonesia should cont to enhance that energy transfer via La Nina like trop forcing's and possible baroclinic enhancement out of that region.    

You can see on the loop that there remains a persistent, albeit weak at the moment, atmospheric river coming out of the E IO between India and Indonesia.  Obv you can also see the energy transfer coming out of the MJo phases 7-8 as well on the loop.    
http://www.goes.noaa.gov/dml/jma/fd/wvblue.html

Anyway these are my concerns regarding the Strat and why despite it being exceptionally favorably weak if the location isn't right we might not benefit as strongly as we might expect from it.  And IF the estronger westerly QBO ends up leading to the re-establishment of a stronger Strat as we head deep into the winter if we don't benefit from the next 45days or so we could be SOL.

[Frank_Wx]

That is a legitimate concern with the cold air being on the other side of the globe. But this is something that does not surprise me. We're going to combat the southeast ridge all winter. The bright spot is the -AO/-NAO could overpower the SE ridge depending on magnitude. This is why I think December could be a thriller. Big storms are poised to effect the area. Not all of them will be white, but I foresee the interior northeast getting slammed with snow.

[Isotherm]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

I don't know man, I still think it may end up being more transient than full-fledged. I hope not, but even though we are seeing the insane Greenland block and the negative AO, I just do not like the look of the stratosphere and the Pacific. Looking at the whole setup, we look to be centered west of the time-mean trough axis, which does not bode well for white gold action :/

Stratosphere looks amazing considering the time of year. It's actually the one bright variable. Please elaborate?

I cant speak for Ray but I am more concerned with positioning regarding the strat.  Its no coincidence that the coldest air in the N hemisphere has been on the wrong side of the globe.  If you actually look at the distribution of the 850 temps and anomalies the coldest locations and the 0*C line pretty much line up with the lower strat circulation(70mb) since the beginning of Nov. And the two coldest spots line up nicely with where the centers of the 70mb vortex is as wll as where the 10mb elongated center is situated over top.  Here it is currently:






Although the Strat vortex is forecast to remain weak and a second warming event toward the end of this month or early next month looks possible, the forecast is for it to remain centered on the other side of the N Hemisphere, at least for the foreseeable future.  I worry that the downward press from a warm strat leads to the heights lowering more consistently in the same locations as now.  Not impossible to get our cold shots into NA but more difficult and more short lived when combined with the concerns in the N Pac.

Here is the 240hr Euro strat forecast location from yesterday:  


 I worry that this will cont to keep the coldest air locked up in asia, and although provide some high latitude blocking it may not allow for a true cross polar flow.  Combine that with concerns in the N Pac.

Yeah I know the AAM is forecast to change which in theory is historically conducive to disrupting the strong N pac jet, but 1) If the current SSTA configuration in the C and N Pac holds strong, which I cant see it changing any time soon despite what may appear like a classive +PDO look around the NE Pac it may not be enough.  and 2) with the extremely cold air in E Asia and the warm waters/SSTA gradient well stablished in the Pac large scale baroclinic enhancement of the Pac jet between E Asia dna the E IO/Indonesia region will remain firmly in place.  This is actually something noted by J Cohan in his latest update:

"On the other hand the North Pacific jet looks to remain highly energetic.  The more energized jet seems to be a response to the very cold temperatures across Siberia and an increased equator to pole temperature gradient.  With no sign of moderating temperatures across Siberia I see little reason to anticipate a slackening of the North Pacific Jet.  A strong North Pacific Jet crossing the West Coast of North America often results in a mild to very mild pattern across the continent and this remains a strong possibility.  However, I wrote last week that I expect a southward displaced North Pacific Jet and for now the models agree."

For me I worry that any disruption for the better to the strong N Pac jet ends up being transient, (a week a month who knows) because of the SSTA and an unfavorable strat position; combine that with an equatorial walker and hadley cell configuration that has persistently behaved in a L Nina fashion as seen by the persistent OLR maps.  When or if the current MJO quiets down will we once again see stronger energy transfer out of the unfavorable MJO phases 4-5-6 again which again would only aid in the enhancement of a stronger N Pac jet?  The almost coast to coast horizontal SSTA configuration in the central and N Pac(warm cold warm from N to S), weak La Nina across the trop Pac combined with the exceptional cold in E Asia and the warm waters located due south around the E IO and Indonesia should cont to enhance that energy transfer via La Nina like trop forcing's and possible baroclinic enhancement out of that region.    

You can see on the loop that there remains a persistent, albeit weak at the moment, atmospheric river coming out of the E IO between India and Indonesia.  Obv you can also see the energy transfer coming out of the MJo phases 7-8 as well on the loop.    
http://www.goes.noaa.gov/dml/jma/fd/wvblue.html

Anyway these are my concerns regarding the Strat and why despite it being exceptionally favorably weak if the location isn't right we might not benefit as strongly as we might expect from it.  And IF the estronger westerly QBO ends up leading to the re-establishment of a stronger Strat as we head deep into the winter if we don't benefit from the next 45days or so we could be SOL.

Scott - check out my winter outlook; I discussed many of those same concerns, such as the latitudinal thermal gradient which will inject extra momentum and the Nina-esque Hadley orientation with off-equator subsidence cells, increasing the intensity of the Pacific Jet. I'm generally anticipating a poor Pacific through most of the winter. Early winter should be blocky in the AO/NAO domains, but my lack of confidence on this truly translating to a great pattern for the East led me to a rather mundane/near normal temp outlook for December. Our best opportunities will come if/when we see a contemporaneous poleward Pacific ridge (ala '10) coupled w/ the Atl/Arc blocking. Otherwise, we'll be fighting marginal temps. I do think we get some windows once further into Dec.

[Frank_Wx]

There are substantial differences between the GFS and EURO when it comes to 500mb set-up for the Thanksgiving Day storm.

Valid 1pm Wednesday 500mb height anomalies GFS:



Upper energy associated with the storm is found over the Great Lakes, but notice how heights ahead of the upper low are positive. This is normally a good indication that any storm that tries to form will cut to our west. The Pacific Jet remains a problem and the ridge over Greenland is transient.


EURO valid same time frame:



Where the GFS has low heights over the Hudson Bay, the EURO shows positive heights but the Pacific remains an issue. However, the favorable positioned heights to our north keeps heights ahead of the upper level low flatter and there is a less likely chance it cuts to our west. In this scenario, there is a weak storm because of the lack of phasing but at least it's not an all out rainstorm on Turkey Day. Areas N&W of NYC would also see snow if the EURO worked out.

Not impressed with the set-up overall. I think the time period following Thanksgiving when a -NAO gets established could be better.

[amugs]

[rb924119]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

I don't know man, I still think it may end up being more transient than full-fledged. I hope not, but even though we are seeing the insane Greenland block and the negative AO, I just do not like the look of the stratosphere and the Pacific. Looking at the whole setup, we look to be centered west of the time-mean trough axis, which does not bode well for white gold action :/

Stratosphere looks amazing considering the time of year. It's actually the one bright variable. Please elaborate?

I cant speak for Ray but I am more concerned with positioning regarding the strat.  Its no coincidence that the coldest air in the N hemisphere has been on the wrong side of the globe.  If you actually look at the distribution of the 850 temps and anomalies the coldest locations and the 0*C line pretty much line up with the lower strat circulation(70mb) since the beginning of Nov. And the two coldest spots line up nicely with where the centers of the 70mb vortex is as wll as where the 10mb elongated center is situated over top.  Here it is currently:

Although the Strat vortex is forecast to remain weak and a second warming event toward the end of this month or early next month looks possible, the forecast is for it to remain centered on the other side of the N Hemisphere, at least for the foreseeable future.  I worry that the downward press from a warm strat leads to the heights lowering more consistently in the same locations as now.  Not impossible to get our cold shots into NA but more difficult and more short lived when combined with the concerns in the N Pac.

Here is the 240hr Euro strat forecast location from yesterday:  

 I worry that this will cont to keep the coldest air locked up in asia, and although provide some high latitude blocking it may not allow for a true cross polar flow.  Combine that with concerns in the N Pac.

Yeah I know the AAM is forecast to change which in theory is historically conducive to disrupting the strong N pac jet, but 1) If the current SSTA configuration in the C and N Pac holds strong, which I cant see it changing any time soon despite what may appear like a classive +PDO look around the NE Pac it may not be enough.  and 2) with the extremely cold air in E Asia and the warm waters/SSTA gradient well stablished in the Pac large scale baroclinic enhancement of the Pac jet between E Asia dna the E IO/Indonesia region will remain firmly in place.  This is actually something noted by J Cohan in his latest update:

"On the other hand the North Pacific jet looks to remain highly energetic.  The more energized jet seems to be a response to the very cold temperatures across Siberia and an increased equator to pole temperature gradient.  With no sign of moderating temperatures across Siberia I see little reason to anticipate a slackening of the North Pacific Jet.  A strong North Pacific Jet crossing the West Coast of North America often results in a mild to very mild pattern across the continent and this remains a strong possibility.  However, I wrote last week that I expect a southward displaced North Pacific Jet and for now the models agree."

For me I worry that any disruption for the better to the strong N Pac jet ends up being transient, (a week a month who knows) because of the SSTA and an unfavorable strat position; combine that with an equatorial walker and hadley cell configuration that has persistently behaved in a L Nina fashion as seen by the persistent OLR maps.  When or if the current MJO quiets down will we once again see stronger energy transfer out of the unfavorable MJO phases 4-5-6 again which again would only aid in the enhancement of a stronger N Pac jet?  The almost coast to coast horizontal SSTA configuration in the central and N Pac(warm cold warm from N to S), weak La Nina across the trop Pac combined with the exceptional cold in E Asia and the warm waters located due south around the E IO and Indonesia should cont to enhance that energy transfer via La Nina like trop forcing's and possible baroclinic enhancement out of that region.    

You can see on the loop that there remains a persistent, albeit weak at the moment, atmospheric river coming out of the E IO between India and Indonesia.  Obv you can also see the energy transfer coming out of the MJo phases 7-8 as well on the loop.    
http://www.goes.noaa.gov/dml/jma/fd/wvblue.html

Anyway these are my concerns regarding the Strat and why despite it being exceptionally favorably weak if the location isn't right we might not benefit as strongly as we might expect from it.  And IF the estronger westerly QBO ends up leading to the re-establishment of a stronger Strat as we head deep into the winter if we don't benefit from the next 45days or so we could be SOL.

Scott (and Isotherm), you CAN speak for me; you took the thoughts right out of my head ahaha So Frank, that's my response as well :p

Secondly, I don't necessarily know if it will be a true southeast ridge. If you look at both sets of ensembles, notice how troughiness and energy is projected to continue to sit just off of our west coast with a ridge axis located generally between the Rockies and Mississippi River downstream. With such an orientation, that keeps a trough over the Northeast, yes, but we will be upstream of the time mean trough axis. With that configuration, I envision energy breaking off from the western trough and working through the ridge, not over top of it (thanks to the Pacific), and essentially moving almost zonally across the US. Since we will already be upstream of the time mean trough axis, it makes it very easy for the system(s) progressing eastward to enhance warm advection ahead of it/them on it's/their own, and with no true influx of cold air from the trough that we will be underneath and the fact that the system(s) will only have moderated Pacific air to work with from the start, the warm advection will likely win out just enough and it will "warm up to rain", then get cold again behind it, as the systems merge with the larger trough and resets its configuration again. However, in a pattern like this, this looks very similar to the second half of '14-'15, when eastern New England got smashed. The same type of pattern looks to be evolving now, broadly speaking.

[amugs]

WOW - if this does occur and orients in the right spot WOOF!!

[sroc4]

[quote="Isotherm"]

December is shaping up to be a thriller. Even Thanksgiving beginning to look promising, especially Black Friday weekend.

Get ready

I don't know man, I still think it may end up being more transient than full-fledged. I hope not, but even though we are seeing the insane Greenland block and the negative AO, I just do not like the look of the stratosphere and the Pacific. Looking at the whole setup, we look to be centered west of the time-mean trough axis, which does not bode well for white gold action :/

Stratosphere looks amazing considering the time of year. It's actually the one bright variable. Please elaborate?

Scott - check out my winter outlook; I discussed many of those same concerns, such as the latitudinal thermal gradient which will inject extra momentum and the Nina-esque Hadley orientation with off-equator subsidence cells, increasing the intensity of the Pacific Jet. I'm generally anticipating a poor Pacific through most of the winter. Early winter should be blocky in the AO/NAO domains, but my lack of confidence on this truly translating to a great pattern for the East led me to a rather mundane/near normal temp outlook for December. Our best opportunities will come if/when we see a contemporaneous poleward Pacific ridge (ala '10) coupled w/ the Atl/Arc blocking. Otherwise, we'll be fighting marginal temps. I do think we get some windows once further into Dec.

Tom I posted some thoughts in here the morning that you posted your winter outlook. At the time I was making observations about the SST anomalies and how they looked and had some preliminary thoughts about the strat that I didn't have time to write about at the time. But your write up really got me to thinking more about the big picture and sparked me to look even more into it. I hope the stratosphere surprises us in a good way going forward.

[Frank_Wx]

Cohen tweeted to "get out the snowplows" based off what he's seeing in the Strat. We'll have to see how the pattern looks week 2 of December (considering lagg effect)

[Frank_Wx]

Between the wind and temperature Strat forecast, I'm 80% confident a SSWE will take place between November 27-30th. 2nd week of Dec is when we'll know if it had a positive or negative effect on our weather pattern here at the Trop.

[Frank_Wx]

ONI plots in all regions of ENSO warmed significantly the week of the 9th. If that trend continues, La Nina may have already peaked. Seems too soon, but you never know.

[Frank_Wx]

CFS aggressive with blocking first 2 weeks of DEC

[Frank_Wx]

This graph has slowly been trending more aggressive with poleward EPV by early DEC. Partly reason for SSWE

[Frank_Wx]

Another CFS look for DEC. Very possible both sides of NH will be under below normal temps while the Arctic experiences record warmth.

[Frank_Wx]

[Frank_Wx]

I guess we could see PV displacement end of this month then a split in early December. 

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