Stratosphere temperature watch - 2016/17

[sebastiaan1973]

https://www.researchgate.net/publication/271737956_Impacts_of_two_types_of_La_Nina_on_the_NAO_during_boreal_winter

There seems to be two types of La Nina with different implications for our weather. We - the winter lovers- need an Eastern Pacific La Nina. E.g. 2006-1996-1985.

 

 

Edited October 4, 2017 by sebastiaan1973

[phil nw.]

19 minutes ago, Interitus said:

Yes, there have been record weak wind speeds in the MERRA 2 dataset, from 50 mb and below related to troposphere circulalion, but some have been getting a bit carried away with the significance of this, and the upper level vortex has been developing as normal.

A weak vortex in October is a poor predictor for strength later in the winter, at least as measured as measured by 10mb wind speed (NCEP reanalysis). There is a weak correlation by persistence to the strength in November (0.27) but none for other months. Persistence leads to higher correlation for consecutive months November-December (0.42), December-January (0.54) and January-February (0.41) but no correlation for lead times more than a month apart. The stopping the plate spinning analogy doesn't seem to apply.

I tend to agree.

Just viewing the October 500hPa NH patterns in the archives will show many recent Octobers with apparent blocking in the Arctic regions where the vortex is actually still forming,IMO this is too early to gauge it's likely strength for Winter.

Very often come late November we see a surge in zonal wind speeds as the Polar night establishes in the higher latitudes with the resultant drop in Stratospheric temperatures.

Just my simplified view based on many years of following the charts.Having said that we appear to be in a better place this year with the E-QBO and heading closer to Solar minimum.

[comet]

From what I can see there is nothing at all unusual  about the QBO and its propagation down through the strat. Posters are trying to find problems when there aren't any and of course it is getting colder at 10mb it would be far more unusual if it wasn't.

[karyo]

On ‎04‎/‎10‎/‎2017 at 15:07, sebastiaan1973 said:

https://www.researchgate.net/publication/271737956_Impacts_of_two_types_of_La_Nina_on_the_NAO_during_boreal_winter

There seems to be two types of La Nina with different implications for our weather. We - the winter lovers- need an Eastern Pacific La Nina. E.g. 2006-1996-1985.

 

 

So far temperatures are colder in the east but of course the location of the coldest SSTs is likely to change in the coming months.

[sebastiaan1973]

Yes, we have to wait and see.

https://www.clim-past.net/13/1199/2017/cp-13-1199-2017.pdf

Abstract

The impact of solar variability on weather and climate in central Europe is still not well understood. In this paper we use a new time series of daily weather types to analyse the influence of the 11-year solar cycle on the tropospheric weather of central Europe. We employ a novel, daily weather type classification over the period 1763–2009 and investigate the occurrence frequency of weather types under low, moderate, and high solar activity level. Results show a tendency towards fewer days with westerly and west-southwesterly flow over central Europe under low solar activity. In parallel, the occurrence of northerly and easterly types increases. For the 1958–2009 period, a more detailed view can be gained from reanalysis data. Mean sea level pressure composites under low solar activity also show a reduced zonal flow, with an increase of the mean blocking  frequency between Iceland andScandinavia. Weather types and reanalysis data show that the 11-year solar cycle influences the late winter atmospheric circulation over central Europe with colder (warmer) conditionsunder low (high) solar activity.

 

[sebastiaan1973]

The conclusions from the article.

Edited October 8, 2017 by sebastiaan1973

[Methuselah]

The problem with using the 11-Year Sunspot Cycle as a tool for weather forecasting is that, as far as I can see, there's no 'useful' correlation...I'm not trying to be either 'funny' or 'facetious'...but, if there were a 'useful' correlation, wouldn't professional meteorologists have been exploiting it for decades? 

[KyleHenry]

Error, duplicate post added to thread above.

Forecasted MJO shows possibilities of Rossby wave formation. If forecast is correct then possible Stratospheric warming at 10 hPa around 20th-25th October.

Influential process to watch out for.

Edited October 8, 2017 by KyleHenry

[feb1991blizzard]

3 hours ago, Ed Stone said:

The problem with using the 11-Year Sunspot Cycle as a tool for weather forecasting is that, as far as I can see, there's no 'useful' correlation...I'm not trying to be either 'funny' or 'facetious'...but, if there were a 'useful' correlation, wouldn't professional meteorologists have been exploiting it for decades? 

On its own, perhaps correlation isn't as strong as some make out, but used in conjuction with other factors, it is, for instance SSW's are more likely in an E-QBO in solar minimum, plus you only have to look back at some of the CET's during weak solar cycles from a couple of hundred years ago to realise its merits.

[jules216]

The correlation between QBO and Solar cycles(Solar Flux) has been documented by Labitzke et.al. before and they found that 10 out of 15 winters in -QBO had at least 1 MMW, also even more MMV in +QBO and Solar Max. see interesting table which also includes ENSO state

[Snowy Hibbo]

Here is the QBO forecast, which is in easterly mode at the moment. But this forecast hints at a slight weakening of the -QBO.

Other things of note, the SAO jet is strengthening in it's current positive mode. Same with the jetstream over the Northern Hemisphere. This seems to somewhat correspond with the current +AO (stronger polar vortex), that is set to continue for the next 10 days at least, with longer term charts (GFS) showing a potential move to neutral AO.  

EPS Control also shows a weakening of the easterly QBO jet over the 10-15 day period. Interesting, will the QBO follow fthe forecast? Will the 'failed' easterly phase happen again?

[Interitus]

21 hours ago, Snowy Hibbo said:

 

EPS Control also shows a weakening of the easterly QBO jet over the 10-15 day period. Interesting, will the QBO follow fthe forecast? Will the 'failed' easterly phase happen again?

 

Whatever happens, the QBO is following a more typical course at present and is already totally different to the 'failed easterly' of last year, as can be seen in the chart below of monthly 30mb equatorial zonal wind -

[Snowy Hibbo]

28 minutes ago, Interitus said:

Whatever happens, the QBO is following a more typical course at present and is already totally different to the 'failed easterly' of last year, as can be seen in the chart below of monthly 30mb equatorial zonal wind -

Fair enough. What I am saying is that it could be weaker than a normal -QBO phase. I had a chat with Paul Roundy on Twitter and he said that the EC model prediction is probably not enough to forecast a QBO reversal properly. Which I agree with, just noting patterns I am watching.

[Interitus]

47 minutes ago, Snowy Hibbo said:

Fair enough. What I am saying is that it could be weaker than a normal -QBO phase. I had a chat with Paul Roundy on Twitter and he said that the EC model prediction is probably not enough to forecast a QBO reversal properly. Which I agree with, just noting patterns I am watching.

Well here is an alternative view to take some account of seasonality. Using the month of easterly wind onset at 30mb as the start of a QBO cycle, the current cycle began June this year. There are five other cycles since 1960 (data prior to this is generally poor) which began in June - 2009, 1991, 1986, 1981 and 1967.

All show an apparent weakening of the easterlies in the autumn or early winter apart from 1981, which does at least display a moderation in strengthening. Then 4 out of 5 have a 25/26 month cycle, with maximum easterlies in the spring or early summer the year after onset. The exception being the long 32 month QBO of 1967 which started out looking like it might return westerly at the beginning. This did happen for the QBO beginning in July '64, which switched back to westerly in October, before commencing again in January '65.

In any case, it can be seen in the graph that this year is stronger than all these previous years at the four month stage (though this could be because QBO amplitude has tended to increase with time in the data).

[karlos1983]

Excuse my ignorance, but what is usually the resulting Troposphere pattern when the PV at 10hpa is displaced over Scandinavia as currently being modelled by the GFS in FI ?

Thanks 

Edited October 11, 2017 by karlos1983

[Snowy Hibbo]

10 hours ago, Interitus said:

Well here is an alternative view to take some account of seasonality. Using the month of easterly wind onset at 30mb as the start of a QBO cycle, the current cycle began June this year. There are five other cycles since 1960 (data prior to this is generally poor) which began in June - 2009, 1991, 1986, 1981 and 1967.

All show an apparent weakening of the easterlies in the autumn or early winter apart from 1981, which does at least display a moderation in strengthening. Then 4 out of 5 have a 25/26 month cycle, with maximum easterlies in the spring or early summer the year after onset. The exception being the long 32 month QBO of 1967 which started out looking like it might return westerly at the beginning. This did happen for the QBO beginning in July '64, which switched back to westerly in October, before commencing again in January '65.

In any case, it can be seen in the graph that this year is stronger than all these previous years at the four month stage (though this could be because QBO amplitude has tended to increase with time in the data).

Interesting. Thanks for that.

[bluearmy]

9 hours ago, karlos1983 said:

Excuse my ignorance, but what is usually the resulting Troposphere pattern when the PV at 10hpa is displaced over Scandinavia as currently being modelled by the GFS in FI ?

Thanks 

Careful Karlos - that's temperature, not height. The lowest height is predicted to be just n of Siberia. 

Given last year's dissapointment re the weak flow at 10hpa failing to lead into anything notable, I'm loathe to comment too much on current patterns. 

[JeffC]

This is always worth a look...

shows the easterly winds round the tropics at 10 hpa, but less distinct at lower levels..https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-337.69,32.91,302/loc=53.168,51.264

 

 

 

 

 

 

 

[Gael_Force]

39 minutes ago, bluearmy said:

Careful Karlos - that's temperature, not height. The lowest height is predicted to be just n of Siberia. 

Given last year's dissapointment re the weak flow at 10hpa failing to lead into anything notable, I'm loathe to comment too much on current patterns. 

For those who reckon the strat has a 'memory'... that's the temp and heights profile last winter ended on. 

[Snowy L]

On 04/10/2017 at 15:07, sebastiaan1973 said:

https://www.researchgate.net/publication/271737956_Impacts_of_two_types_of_La_Nina_on_the_NAO_during_boreal_winter

There seems to be two types of La Nina with different implications for our weather. We - the winter lovers- need an Eastern Pacific La Nina. E.g. 2006-1996-1985.

 

 

So would the Nino 1+2 region be the more important region to look at? This one is currently in a moderate La Nina state while 3.4 region is neutral. Would this count as an Eastern Pacific La Nina?

[Daniel*]

Interest builds. 

 

[Paul123]

On 4-10-2017 at 16:21, phil nw. said:

Just my simplified view based on many years of following the charts.Having said that we appear to be in a better place this year with the E-QBO and heading closer to Solar minimum.

Simply E-QBO and sunspot number <50

                                                               

To the right: E-QBO and sunspot number <50, without winters with new cycle W-QBO cycle starting in upper stratosphere.

:Look much better than we have had recent years:

Hoping the E-QBO won't fade away as has been suggested by the ECMWF.

 

 

Edited October 14, 2017 by Paul123

[comet]

19 hours ago, Daniel* said:

Interest builds. 

 

The gfs has been showing this for a few days now. It would of course be a lot more interesting 5-6 weeks from now.

[bluearmy]

Early days and checking through the Berlin charts this morning, the wave 1 increasing in the second part of the run and the zonal flow higher up at higher lat weakening in tandem as the vortex is displaced towards Siberia. This is bang in line with GEFS forecasts and the high anomaly with associated gentle warming over the Canadian side offers further encouragement. However. it's just that (for the time being) for those looking for a cold start to winter this year. Slowly, slowly ..........

 

[knocker]