Stratosphere temperature watch - 2016/17

[knocker]

I see chio's been chatting on twitter

 

[Paul_1978]

What is "Conus"?

[cheshire snow]

6 minutes ago, Paul_1978 said:

What is "Conus"?

Continental United States

C.S

[Weather-history]

6 minutes ago, Paul_1978 said:

What is "Conus"?

Continental United States

[mountain shadow]

Its Contigious United States. The 48 States which are connected. It excludes Hawaii and Alaska.

[Paul123]

I see no hope for any relevant disturbance of the polar vortex within two or three weeks (see picture). 

I think the stratosphere is playing a significant role in spoiling the potential for cold weather in Western Europe these days. 

It seems the long term potential for wintery weather is partially a relict of the Canadian warming, end November, early December. There are still vast areas of below normal temperatures (Canada, Siberia), they continue to have a blocking effect on the tropospheric PV. 
 

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=0&mode=10&carte=1

Edited January 3, 2017 by Paul123

[Interitus]

On 12/17/2016 at 13:10, Interitus said:

Forgot to add that at the moment, perhaps the most interesting part of these strat forecasts such as this 30mb temperature chart -

- may be the opportunity to see some nacreous clouds.

That temperature chart verified quite well -

Lo and behold courtesy of twitter -

Just a couple of samples from Norway, there are others elsewhere in Scandinavia and there could be a chance to see some from northern parts of the UK, in Scotland especially closest to the lowest temperatures. Also cooling from orographic wave uplift helps generate the clouds locally and may give the lenticular shape in these photos.

[Spah1]

 

[Gael_Force]

December QBO was at 15.09 and the strongest westerly December in the data set. Probably one reason why the early season promise was way off the mark.

https://www.esrl.noaa.gov/psd/data/correlation/qbo.data

 

[Weather-history]

 

[WINTRY WALES]

2 hours ago, Weather-history said:

 

Does this mean another high pressure over central Europe.....another Europe slug?? please nooooooooo

[Gael_Force]

2 hours ago, WINTRY WALES said:

Does this mean another high pressure over central Europe.....another Europe slug?? please nooooooooo

GFS 6z agrees with the 2 wave squeeze.

I don't think that is a good pattern for us as an eventual split would leave a bit of vortex over Greenland. The good wave action in previous winters needs the axis of split to be Greenland to east Siberia.

[Catacol]

On 04/01/2017 at 21:42, Gael_Force said:

December QBO was at 15.09 and the strongest westerly December in the data set. Probably one reason why the early season promise was way off the mark.

https://www.esrl.noaa.gov/psd/data/correlation/qbo.data

 

Yes - there is time to run yet... but looking back over my lifetime I cant see a single one of the memorable cold spells I have experienced occur in such a positive QBO phase. The correlation between cold spells and eQBO is fairly clear. I have already posted on the MOD thread that if this winter doesnt deliver a cold spell then I think the QBO will be responsible. Such a pity because we had really good building blocks early on, but such a strong index has made vortex coherence fairly sound.

I have no idea what the profile for hte QBO will look like in 11 months' time - its rhythm has been so altered looking at the graphs that its anyone's guess. Hopefully we can see a much lower value.. and who knows - maybe a very low value.....

[ArHu3]

6 hours ago, Catacol said:

Yes - there is time to run yet... but looking back over my lifetime I cant see a single one of the memorable cold spells I have experienced occur in such a positive QBO phase. The correlation between cold spells and eQBO is fairly clear. I have already posted on the MOD thread that if this winter doesnt deliver a cold spell then I think the QBO will be responsible. Such a pity because we had really good building blocks early on, but such a strong index has made vortex coherence fairly sound.

I have no idea what the profile for hte QBO will look like in 11 months' time - its rhythm has been so altered looking at the graphs that its anyone's guess. Hopefully we can see a much lower value.. and who knows - maybe a very low value.....

I think it's pretty cold, exceptionally cold even in some areas, just about everywhere on the NH except the Benelux, Northerns France and UK even normally not so cold areas as the US west coast, Northern Africa, Middle East and eastern mediterranean

[Gael_Force]

Talking about the cold going into Greece reminds me of some of the winters in the mid noughties. There were no threads for the strat then so not sure what was going on but just a suggestion based on past reading. Solar activity winding down was enough to create a meridional pattern but not enough to get the cold backing west, especially with no help from QBO.

The papers on Kara-Barents low ice anomaly and even the SAI warm arctic cold continents are being tested and not actually failing, IMO. Their focus was on mainland Europe cold, it is very cold in parts ... the UK is always an anomaly in this kind of set up. Really very close and may get there given another year or two.

Edited January 6, 2017 by Gael_Force

[mountain shadow]

13 minutes ago, Gael_Force said:

The papers on Kara-Barents low ice anomaly and even the SAI warm arctic cold continents are being tested and not actually failing, IMO. Their focus was on mainland Europe cold, it is very cold in parts ... the UK is always an anomaly in this kind of set up. Really very close and may get there given another year or two.

I agree, the SAI has zero bearing on whether the Uk will get proper snowy cold or not. I'm not sure there is any index which would guarantee us proper cold as we need 19 or 20 things to workout correctly at the same time, if 1 fails, it all fails.

[Interitus]

16 hours ago, Catacol said:

Yes - there is time to run yet... but looking back over my lifetime I cant see a single one of the memorable cold spells I have experienced occur in such a positive QBO phase. The correlation between cold spells and eQBO is fairly clear. I have already posted on the MOD thread that if this winter doesnt deliver a cold spell then I think the QBO will be responsible. Such a pity because we had really good building blocks early on, but such a strong index has made vortex coherence fairly sound.

I have no idea what the profile for hte QBO will look like in 11 months' time - its rhythm has been so altered looking at the graphs that its anyone's guess. Hopefully we can see a much lower value.. and who knows - maybe a very low value.....

Well as December had the highest QBO of any winter month in the NOAA data linked above, then obviously your first statement is absolutely correct. However, unless you are less than six years old then you would've experienced December 2010 with QBO 10.97.

Even colder? February 1986 QBO 10.15.

There is no statistical correlation between CET and QBO for December or February, and a tentative 0.24 for January.

However, the data does appear to show cooler CET for eQBO, worth around 0.2°C for December and February and a more notable half degree for January (though Jan 1963 skews this somewhat) and this persists after taking into account that eQBO is stronger than wQBO so the mean is easterly.

When looking at more extreme QBO values greater +/- 1 sd the picture is more muddled - though there is a problem with small and uneven sample sizes so must be taken with a pinch of salt.

The December difference is the same, but both are above average (+0.2 / +0.4).

January seems more clear cut with means of 3.47°C (1963 is worth 0.3 degrees) and 4.75°C - may be reflected in the weak correlation noted above and worthy of some investigation, though is not statistically significant - we have had a prolonged run of generally mild Januaries regardless of QBO.

February has no difference in CET between extreme east or west QBO - this is perhaps the most interesting bearing in mind links between QBO and late winter stratospheric vortex strength.

But, to say that QBO is responsible for whether we have notable cold spells is more than a bit of a stretch.

[snowwman]

2 minutes ago, Interitus said:

Well as December had the highest QBO of any winter month in the NOAA data linked above, then obviously your first statement is absolutely correct. However, unless you are less than six years old then you would've experienced December 2010 with QBO 10.97.

Even colder? February 1986 QBO 10.15.

There is no statistical correlation between CET and QBO for December or February, and a tentative 0.24 for January.

However, the data does appear to show cooler CET for eQBO, worth around 0.2°C for December and February and a more notable half degree for January (though Jan 1963 skews this somewhat) and this persists after taking into account that eQBO is stronger than wQBO so the mean is easterly.

When looking at more extreme QBO values greater +/- 1 sd the picture is more muddled - though there is a problem with small and uneven sample sizes so must be taken with a pinch of salt.

The December difference is the same, but both are above average (+0.2 / +0.4).

January seems more clear cut with means of 3.47°C (1963 is worth 0.3 degrees) and 4.75°C - may be reflected in the weak correlation noted above and worthy of some investigation, though is not statistically significant - we have had a prolonged run of generally mild Januaries regardless of QBO.

February has no difference in CET between extreme east or west QBO - this is perhaps the most interesting bearing in mind links between QBO and late winter stratospheric vortex strength.

But, to say that QBO is responsible for whether we have notable cold spells is more than a bit of a stretch.

Nice bit of research. I came to the same conclusion re. Westerly QBOs. They don't spell mild. They seem more likely than Easterly QBOs to be correlated with extreme mild or extreme cold.

[summer blizzard]

Interesting stratospheric picture that develops between days 5 and 10 with a degree of warming and some pressure to displace the vortex over time. If the picture is sustained then i'd be more inclined to believe that late Jan/Feb could see a more sustained -AO picture regardless of whether we achieve a SSW (not forecast by the GFS as of yet). 

[Catacol]

13 hours ago, ArHu3 said:

I think it's pretty cold, exceptionally cold even in some areas, just about everywhere on the NH except the Benelux, Northerns France and UK even normally not so cold areas as the US west coast, Northern Africa, Middle East and eastern mediterranean

Not really my point. A wQBO doesn't mean there is less cold around - what it means in my book is that it is harder to achieve the high lat blocking necessary for winter to hit the uk. Continental land masses suffer no such issues. Perhaps an eQBO makes a PC feed more difficult? Looking only at CET doesn't quite tell the whole story.

Having said that I haven't researched it. Just a gut feeling based on memory and observation.

Edited January 6, 2017 by Catacol

[iapennell]

On 1/2/2017 at 09:36, Paul123 said:

I see no hope for any relevant disturbance of the polar vortex within two or three weeks (see picture). 

I think the stratosphere is playing a significant role in spoiling the potential for cold weather in Western Europe these days. 

It seems the long term potential for wintery weather is partially a relict of the Canadian warming, end November, early December. There are still vast areas of below normal temperatures (Canada, Siberia), they continue to have a blocking effect on the tropospheric PV. 
 

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=0&mode=10&carte=1

Agreed. The wind and temperature profile of the high-latitude Stratosphere are supportive of a continuation of healthy Polar Night Westerlies for some time to come. That means continued healthy Ferrel Westerlies at higher mid-latitudes bringing warmth off the North Atlantic to all of mainland Britain.

[shotski]

2 minutes ago, iapennell said:

Agreed. The wind and temperature profile of the high-latitude Stratosphere are supportive of a continuation of healthy Polar Night Westerlies for some time to come. That means continued healthy Ferrel Westerlies at higher mid-latitudes bringing warmth off the North Atlantic to all of mainland Britain.

Hi , at what time scale are we talking for the warmth off the North Atlantic. 

Thanks

[iapennell]

1 minute ago, shotski said:

Hi , at what time scale are we talking for the warmth off the North Atlantic. 

Thanks

The North Atlantic looks set to dominate for the remainder of the winter, possibly even more so towards March because by then the effects of the record Westerly QBO (15 m/s and 9 m/s at 30 mb and 50 mb respectfully) will have fed into the Northern hemisphere General Circulation- there is a time lag of two-three months typically. The far North Atlantic is still warmer than normal overall and Greenland/NE Canada are at their coldest by February which will encourage an even stronger baroclinic gradient across the far North Atlantic just south of Greenland (this is a site of major cyclogenesis for the deep depressions that pass to the north of Britain and bring strong west or SW winds). None of this portends any strong high-latitude blocking heading through the second half of the winter and towards spring.

The strength of the Westerlies in the sub-polar Stratosphere looks set to remain strong (Westerlies at 10 mb over 60N projected to be around 30 m/s over the next 10 days- see the Weatheriscool.com site) and there are no indications that this will shift radically in the coming days. Given the patterns of temperature across the far North Atlantic and far North Pacific combined with the fact that the central Arctic typically reaches it's coldest during February-early March this is all supportive of a healthy tropospheric Circumpolar Vortex with high-pressure in the sub-tropics and over continental interiors but persistent strong cyclogenesis up-wind of higher-latitude western continental margins such as NW Europe.   

[shotski]

3 minutes ago, iapennell said:

The North Atlantic looks set to dominate for the remainder of the winter, possibly even more so towards March because by then the effects of the record Westerly QBO (15 m/s and 9 m/s at 30 mb and 50 mb respectfully) will have fed into the Northern hemisphere General Circulation- there is a time lag of two-three months typically. The far North Atlantic is still warmer than normal overall and Greenland/NE Canada are at their coldest by February which will encourage an even stronger baroclinic gradient across the far North Atlantic just south of Greenland (this is a site of major cyclogenesis for the deep depressions that pass to the north of Britain and bring strong west or SW winds). None of this portends any strong high-latitude blocking heading through the second half of the winter and towards spring.

The strength of the Westerlies in the sub-polar Stratosphere looks set to remain strong (Westerlies at 10 mb over 60N projected to be around 30 m/s over the next 10 days- see the Weatheriscool.com site) and there are no indications that this will shift radically in the coming days. Given the patterns of temperature across the far North Atlantic and far North Pacific combined with the fact that the central Arctic typically reaches it's coldest during February-early March this is all supportive of a healthy tropospheric Circumpolar Vortex with high-pressure in the sub-tropics and over continental interiors but persistent strong cyclogenesis up-wind of higher-latitude western continental margins such as NW Europe.   

Thanks, much appreciated. 

[feb1991blizzard]

1 hour ago, summer blizzard said:

Interesting stratospheric picture that develops between days 5 and 10 with a degree of warming and some pressure to displace the vortex over time. If the picture is sustained then i'd be more inclined to believe that late Jan/Feb could see a more sustained -AO picture regardless of whether we achieve a SSW (not forecast by the GFS as of yet). 

I disagree, that could well lead to below average temperatures and dry weather for the UK (and probably what the UKMO are basing their 30 dayer on) but we really need drive waves into the heart of that vortex for any sustained -AO and HLB.