Stratosphere and Polar Vortex Watch 2020

[jules216]

2 hours ago, sebastiaan1973 said:

For the end of October. 

Table od Canadian warming events

[Ols500]

is a canadain warming good for cold in uk?

[jules216]

14 minutes ago, Ols500 said:

is a canadain warming good for cold in uk?

It does no harm - 1976/77 or 1981/82 both early warmings

[northwestsnow]

43 minutes ago, Ols500 said:

is a canadain warming good for cold in uk?

Yup , the earlier the better...

[Mike Poole]

5 hours ago, northwestsnow said:

Yup , the earlier the better...

I think this year, we might be looking at high latitude blocking delivered right from the word go in winter, because of the hangover from the highly meridional pattern we have had for simply ages.  See my post in the MOD for more on that.  If that is the case, and it depends how autumn pans out, we may not want a SSW or anything else to throw things up in the air.  I’m thinking 2010 for an analogue to the coming winter.  Which would mean a cold December, but warmer early 2022.  

[damianslaw]

6 hours ago, jules216 said:

It does no harm - 1976/77 or 1981/82 both early warmings

Both brought severe Decembers, but the cold eased in January.. along with 96-97 and 10-11 what you might classify as 'front loaded' winters. 

[damianslaw]

21 minutes ago, Mike Poole said:

I think this year, we might be looking at high latitude blocking delivered right from the word go in winter, because of the hangover from the highly meridional pattern we have had for simply ages.  See my post in the MOD for more on that.  If that is the case, and it depends how autumn pans out, we may not want a SSW or anything else to throw things up in the air.  I’m thinking 2010 for an analogue to the coming winter.  Which would mean a cold December, but warmer early 2022.  

There have been a number of early cold winters that were mild/very mild second half, 76-77, 81-82, 96-97 and 10-11. To a lesser extent joined by 92-93, 01-02 - the Decembers of both were cold and frosty rather than particularly snowy. As someone who likes January to be the king cold month, I'd prefer the cold to start a bit later in December and hold into February, last time that happened was 2009-2010, though last year came close, that period especially in the north was consistently quite cold or cold.

[bluearmy]

Updated 46 is still persisting with the Aleutian low

10mb strat wind forecast for late oct and into nov even more suppressed than previous run 

[sheikhy]

1 minute ago, bluearmy said:

Updated 46 is still persisting with the Aleutian low

10mb strat wind forecast for late oct and into nov even more suppressed than previous run 

Surpression a good thing for us snow lovers right?

[bluearmy]

5 minutes ago, sheikhy said:

Surpression a good thing for us snow lovers right?

Theoretically………

[blizzard81]

21 minutes ago, bluearmy said:

Updated 46 is still persisting with the Aleutian low

10mb strat wind forecast for late oct and into nov even more suppressed than previous run 

And so the 21/22 winter roller-coaster begins. Lets hope it's one of those rare winters that delivers more ups than downs. 

[sebastiaan1973]

A clear picture of lesser zonal winds than normal. One member with a SSW 

Edited September 24, 2021 by sebastiaan1973

[sebastiaan1973]

Bluearmy talked about the Aleutian low, this in combination with high pressure at NW-Russia. 

[SqueakheartLW]

On 24/09/2021 at 09:50, sebastiaan1973 said:

Bluearmy talked about the Aleutian low, this in combination with high pressure at NW-Russia. 

Guess that means the polar vortex is toast, like it. Bring on the cold.

[northwestsnow]

17 hours ago, bluearmy said:

Updated 46 is still persisting with the Aleutian low

10mb strat wind forecast for late oct and into nov even more suppressed than previous run 

eQBO interference I guess.

Are we going hunting for Scandy highs in November??

 

[jules216]

Good things come to those who ask for them. ECMWF 10hPa temperatures now available free in extended forecast section

 

 

[sebastiaan1973]

They are alreay accessible 

https://twitter.com/SimonLeeWx/status/1441378535034155010

https://twitter.com/SimonLeeWx/status/1441376676668010501

The developments got the interest of Simon Lee. Something is going on... 

 

[SqueakheartLW]

I noticed these blue weaker than average zonal wind anomalies are getting ever present in the medium to long range time on these charts now

This one for example sees the vortex grow for a short time before it then just stabilizes at roughly the same speeds at all levels so therefore dips from stronger than average down to weaker than average. A positive sign for the up coming winter if this can be maintained

[SqueakheartLW]

Next run and a repeat performance with the vortex in the Stratosphere with those weaker than average anomalies.

[damianslaw]

Haven't we gone into winter in many recent years with weak zonal winds only for them to ramp into gear in December. I recall this was the case in 2016, 2018 and 2019. Last year as well.

Edited September 26, 2021 by damianslaw

[Eagle]

Hi, it's my first message here but i have a good experience in seasonal forecast (i establish that since 2018) and teleconnections, and look here regularly. My question is the following : the QBO are in a descending phase but the temperature do not follow that for the first time in records (no coupling between high and low stratosphere this one, and intensity of negative temperature anomaly are low). The temperature are warm in high and low strat when is should be colder. The following figure showing that :

 

 

 

We observe a total deconnection between high and low stratosphere and between zonal wind & temperature (the temperature usually following zonal wind, but this drastically opposed this one, looks like the reverse of 2016-2017 cold anomalies). Normally, we observe a cold anomalies in high stratosphere, but not this time (the cold anomaly have suddently spread in early 2021).

I think this could hide a +QBO in a -QBO because warm anomaly are spreading and negative temperature anomaly intensity are low. What do you think, @SqueakheartLW, @jules216, @sebastiaan1973 and other ? Is a +QBO phase hidden in the -QBO is possible ? Or the temperature do not influence the atmospheric response to the zonal wind (no interference ?), thanks you for your response !

[sundog]

1 hour ago, damianslaw said:

Haven't we gone into winter in many recent years with weak zonal winds only for them to ramp into gear in December. I recall this was the case in 2016, 2018 and 2019. Last year as well.

Yes, I think for example in Nov 2018 or 2019 cant remember exactly  which in particular , things looked interesting heading into the winter. But no sooner had we entered the first week of Dec it all turned to S##t.  It was kinda funny in a way,things looking so promising and then suddenly as we entered winter it all feel off the rails rapidly. 

Edited September 26, 2021 by sundog

[Dorsetbred]

4 hours ago, damianslaw said:

Haven't we gone into winter in many recent years with weak zonal winds only for them to ramp into gear in December. I recall this was the case in 2016, 2018 and 2019. Last year as well.

it does make you wonder, if this is going to happen again, which makes me wonder looking at everything going on are trying to analyse the month of December (and beyond)  a little early? Just seems a tad early to really have a firm grasp on the season..I appreciate it is a "forecast"..

Edited September 26, 2021 by Dorsetbred

[jules216]

3 hours ago, Eagle said:

Hi, it's my first message here but i have a good experience in seasonal forecast (i establish that since 2018) and teleconnections, and look here regularly. My question is the following : the QBO are in a descending phase but the temperature do not follow that for the first time in records (no coupling between high and low stratosphere this one, and intensity of negative temperature anomaly are low). The temperature are warm in high and low strat when is should be colder. The following figure showing that :

 

 

 

We observe a total deconnection between high and low stratosphere and between zonal wind & temperature (the temperature usually following zonal wind, but this drastically opposed this one, looks like the reverse of 2016-2017 cold anomalies). Normally, we observe a cold anomalies in high stratosphere, but not this time (the cold anomaly have suddently spread in early 2021).

I think this could hide a +QBO in a -QBO because warm anomaly are spreading and negative temperature anomaly intensity are low. What do you think, @SqueakheartLW, @jules216, @sebastiaan1973 and other ? Is a +QBO phase hidden in the -QBO is possible ? Or the temperature do not influence the atmospheric response to the zonal wind (no interference ?), thanks you for your response !

I dont have the answer to that unfortunatelly Most of studies are related to zonal winds rather then temperatures, but we will find out soon as -QBO as described by 30hPa levele should correlate to enhanced EP flux in November so if this happens then we may not need to worry too much,but I wouldnt be able state anything now with confidence

[SqueakheartLW]

On 26/09/2021 at 13:43, Eagle said:

Hi, it's my first message here but i have a good experience in seasonal forecast (i establish that since 2018) and teleconnections, and look here regularly. My question is the following : the QBO are in a descending phase but the temperature do not follow that for the first time in records (no coupling between high and low stratosphere this one, and intensity of negative temperature anomaly are low). The temperature are warm in high and low strat when is should be colder. The following figure showing that :

 

 

 

We observe a total deconnection between high and low stratosphere and between zonal wind & temperature (the temperature usually following zonal wind, but this drastically opposed this one, looks like the reverse of 2016-2017 cold anomalies). Normally, we observe a cold anomalies in high stratosphere, but not this time (the cold anomaly have suddently spread in early 2021).

I think this could hide a +QBO in a -QBO because warm anomaly are spreading and negative temperature anomaly intensity are low. What do you think, @SqueakheartLW, @jules216, @sebastiaan1973 and other ? Is a +QBO phase hidden in the -QBO is possible ? Or the temperature do not influence the atmospheric response to the zonal wind (no interference ?), thanks you for your response !

The best way to explain this is to line up the temperature charts with the QBO wind speed charts as shown below to get a better idea of how temperature is related to QBO phase and speed

Take the first charts that head back to 1980

The first immediate and obvious pattern you can see here is how warmer temperatures precede the descent of a WQBO and colder temperatures precede the EQBO by several months in advance.

This pattern is generally smooth and regular but in 2016 and again in 2020 you can see a clear alteration to the usual temperature profiles you would expect. This is no doubt related to the two disruption events that took place in those years. Those warmer episodes blocked the usual descent of the EQBO in both cases and resulted in a return of the WQBO in both 2016 and 2020 when it should have gone to an EQBO.

The temperatures are not hiding another QBO phase within the opposing one. Think of it like what happens with the polar vortex as it forms and decays every year. Stratospheric temperatures cool over the pole first followed by the formation of the polar vortex as we move from summer to winter. When summer returns the stratosphere warms followed by the decay of the polar vortex with a lag of many weeks. For the QBO the reaction to the temperature change is months rather than weeks.

Now to come to the more detailed recent temperatures and QBO phases charts with my own additions

1 - Notice this warmer area in the lower stratosphere. This is no doubt a sign that the WQBO in this lower area is likely to persist for a few more months at least, probably early next year at the very minimum.

2 - The appearance of this warmer area in the higher part of the stratosphere is probably a sign that the next new WQBO phase isn't too far away now at the 10 to 20hpa level

3 - What is the good sign for the winter is how there is still a colder zone here at the 30hpa level. This is a sure sign that the current EQBO has a good number of months to run yet

What is very likely to happen with the temperature chart is that the warm region lower down will weaken then go colder in advance of the EQBO getting down to the lowest region of the stratosphere and I would no doubt expect to see the warmer region higher up expand and descend in advance of the WQBO doing the same

Now to put this into the QBO chart with the predicted state of the QBO phases added on to the end of the chart

Just a prediction of mine but I'm basing it purely on the temperature profile in recent times

The above is how I expect the WQBO and EQBO regions to appear on this chart over the next few months. Maybe not exactly like this but a prediction.

I'm expecting 10 to 20hpa to soon head into a WQBO but then like we saw in the descent of the EQBO during 1999 to 2001 we could see a slower than normal progression so we could end up with an extended period of EQBO at 30hpa which could possibly persist well into next year if we keep the current temperature profile going for some time.