Stratosphere temperature watch - 2016/17

[Singularity]

2 hours ago, sebastiaan1973 said:

http://m.uploadedit.com/ba3s/1478101037778.pdf yet another forecast for a double sided winter. First part more chance for cold, negative NAO, second part probably warmer with postive NAO.

The assumptions made regarding the atmospheric response to La Niña may prove unwise... but it's impossible to be certain of that - it just means even lower confidence than usual. Delightful isn't it? (!)

[MattH]

Just a quick one, but the below images are being posted sort as a reference for moving forward to see if they actually verify towards the end of November. The charts from Hannah's site have shown a zonal wind at or below 0 before, but as of yet that clearly hasn't happened. Ignoring the GFS DET run image, for now, and looking more at the GEFS graph, with the exception of around 4 or 5 members, most show zonal winds reversing and dropping below 0 towards the end of the month. Equally looking at the 00Z GFS charts at 10hpa and 30hpa then that is one poorly start vortex at the end of the run, especially at 30hpa it is barely present, but even at 10hpa the large area of higher heights over the pole is telling as is the signal for warming over Russia and Asia, this perhaps directly related to the short-term and on-going development of higher pressure over E Europe and W Russia. Let's see if these charts verify, but whilst a late November SSW is indeed rare and I still think it won't happen just yet, there is most definitely scope for the vortex to get 'properly' ripped apart into December and this is in-keeping with longer term developments and thoughts over the blocked regime being dominant through December as a whole...FYI the Netweather winter forecast is coming along nicely and myself and Tony (Lorenzo) will have this finished by no later than the 25th November.

Regards, Matt.

[bluearmy]

steady as she goes matt

interesting re a ssw

under normal circumstance, we expect an ssw to reverse the flow and bring sudden changes, sometimes quick response and then the lagged propagation down to the trop from the upper strat. 

however, we don't have a strong vortex to begin with so i can't see it's particularly important to get a reversal. just more wave breaking to keep the fellow stuck at 40/50N and above 10hpa will suffice. The trop can continue to play its own tune.

[MattH]

1 hour ago, bluearmy said:

steady as she goes matt

interesting re a ssw

under normal circumstance, we expect an ssw to reverse the flow and bring sudden changes, sometimes quick response and then the lagged propagation down to the trop from the upper strat. 

however, we don't have a strong vortex to begin with so i can't see it's particularly important to get a reversal. just more wave breaking to keep the fellow stuck at 40/50N and above 10hpa will suffice. The trop can continue to play its own tune.

Yes, steady as she goes and yes as you say it's not a requirement, as such, to get a reversal to help change the broader patterns and evolution. It is almost a 'win win' situation so far in that the blocked regime so far this autumn and most likely into early December hasn't primarily come about due to a SSW. Clearly if one were to occur then it would be the 'icing on the cake' as the saying goes, but I agree there completely that a full-on SSW to help introducing northern blocking isn't required in the short term at all, I would image if one did occur it may well do nothing more than just reinforce what we already have, in theory at least.

Clearly compared with 12 months ago we are at the other end of the scale and for those who like cold and wintry weather then the next 4 to 6 weeks are going to be very, very interesting indeed I feel.

Cheers, Matt.

[Timbo]

2 hours ago, MattHugo said:

Just a quick one, but the below images are being posted sort as a reference for moving forward to see if they actually verify towards the end of November. The charts from Hannah's site have shown a zonal wind at or below 0 before, but as of yet that clearly hasn't happened. Ignoring the GFS DET run image, for now, and looking more at the GEFS graph, with the exception of around 4 or 5 members, most show zonal winds reversing and dropping below 0 towards the end of the month. Equally looking at the 00Z GFS charts at 10hpa and 30hpa then that is one poorly start vortex at the end of the run, especially at 30hpa it is barely present, but even at 10hpa the large area of higher heights over the pole is telling as is the signal for warming over Russia and Asia, this perhaps directly related to the short-term and on-going development of higher pressure over E Europe and W Russia. Let's see if these charts verify, but whilst a late November SSW is indeed rare and I still think it won't happen just yet, there is most definitely scope for the vortex to get 'properly' ripped apart into December and this is in-keeping with longer term developments and thoughts over the blocked regime being dominant through December as a whole...FYI the Netweather winter forecast is coming along nicely and myself and Tony (Lorenzo) will have this finished by no later than the 25th November.

Regards, Matt.

Hi Matt, with reference to the Net weather Winter forecast !!!!, any clues to how cold and snowy it is likely to be

[snowbunting]

Really interesting reading. Thanks Matt. Cannot wait for the LRF from you and Tony. I am just a mere avid amatuer at forecasting but your thoughts reflect my own. Nly blocking will prevail and this winter will be very different to the last two winters here in the Western Isles. 

[Connor Bailey Degnan]

Incredible warming event, 384hrs yes, but wow.

[Nouska]

Here's a very good analysis of QBO phase relationship to cold CET winter months - written by Global Warming, the Weather Outlook's CET competition organiser. It also has a relevance to postings in the forecast thread from @iapennell.

Perhaps it is no co-incidence we are seeing a late November 2010 redux in some NWP outlook.

http://www.theweatheroutlook.com/twocommunity/default.aspx?g=posts&m=838758#post838758

 

[Glacier Point]

GFS op and EPS / GEFS means beginning to offer a little more evidence to a substantive stratospheric disturbance as we start the winter.

Keep in mind that the pattern from around 19th Nov for a period of several days builds a strong mid tropospheric ridge over East Europe / Western Russia.

That is perfect for upward wave 2 deflection into the stratosphere. The vortex is already very weak and it won't take much to break it down, wave 2 probably timed for late Nov into early December. My early season analogues hinting at a new vortex forming over the Canadian sector, well displaced from the Pole.

This would be my punt for early December as to how the pieces of the jigsaw will be arranged in the stratosphere...

Door wide open for Arctic ridge and deeply negative AO.

Edited November 14, 2016 by Glacier Point

[phil nw.]

It's quite notable to see the mean zonal winds still forecasted to remain well below normal.

Below is the graph and days 5/10 ECM forecasts

The extent top to bottom of the -ve anomalies from 50N to the Pole is quite striking.It's little wonder that 500hPa modeling is showing such a disrupted jet stream.

 

 

 

[ArHu3]

26 minutes ago, phil nw. said:

It's quite notable to see the mean zonal winds still forecasted to remain well below normal.

Below is the graph and days 5/10 ECM forecasts

The extent top to bottom of the -ve anomalies from 50N to the Pole is quite striking.It's little wonder that 500hPa modeling is showing such a disrupted jet stream.

 

 

 

I really wonder what November 62 and 78 looked like

Edited November 14, 2016 by ArHu3

[phil nw.]

7 minutes ago, ArHu3 said:

I really wonder what November 62 and 78 looked like

Interestingly there were Canadian warmings early on in both those years 

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

so i would imagine the vortex was undermined going into Winter.

[feb1991blizzard]

These are from 20th Nov 1962, they will disappear quickly though as I can never get these charts to stick, so heres the link, you can order lots of different variables on these maps, I love playing about with these but as I say, I cant usually post them as they disappear.

http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/comp.day.pl?var=Geopotential+Height&level=10mb&iy[1]=1962&im[1]=11&id[1]=20&iy[2]=&im[2]=&id[2]=&iy[3]=&im[3]=&id[3]=&iy[4]=&im[4]=&id[4]=&iy[5]=&im[5]=&id[5]=&iy[6]=&im[6]=&id[6]=&iy[7]=&im[7]=&id[7]=&iy[8]=&im[8]=&id[8]=&iy[9]=&im[9]=&id[9]=&iy[10]=&im[10]=&id[10]=&iy[11]=&im[11]=&id[11]=&iy[12]=&im[12]=&id[12]=&iy[13]=&im[13]=&id[13]=&iy[14]=&im[14]=&id[14]=&iy[15]=&im[15]=&id[15]=&iy[16]=&im[16]=&id[16]=&iy[17]=&im[17]=&id[17]=&iy[18]=&im[18]=&id[18]=&iy[19]=&im[19]=&id[19]=&iy[20]=&im[20]=&id[20]=&monr1=1&dayr1=1&monr2=1&dayr2=1&iyr[1]=&filenamein=&plotlabel=&lag=0&labelc=Color&labels=Shaded&type=2&scale=&label=0&cint=&lowr=&highr=&istate=0&proj=Northern+Hemisphere&xlat1=&xlat2=&xlon1=&xlon2=&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

 

 

Edited November 14, 2016 by feb1991blizzard
To stabalise images, thanks to poster below.

[Gael_Force]

35 minutes ago, feb1991blizzard said:

These are from 20th Nov 1962, they will disappear quickly though as I can never get these charts to stick, so heres the link, you can order lots of different variables on these maps, I love playing about with these but as I say, I cant usually post them as they disappear.

I've saved your images on Imgur. Links below if you want to change them in your post.

http://i.imgur.com/MvarTwE.gif

http://i.imgur.com/uOvSlrU.gif

[lorenzo]

Best one I have seen this season.. margin for error or negligible impact narrowing, that's considerably below the line.

Couple of degrees away from the classic definition on Berlin.

 

[Summer Sun]

 

[Sperrin]

Hi Guys, some excellent reading in here and over on the model thread as always. However, the colour charts depicting the strat vortex (below) completely stump me. I wonder is there any where I could find a blog/article that explains how to interpret them? 

[mountain shadow]

1 hour ago, Sperrin said:

Hi Guys, some excellent reading in here and over on the model thread as always. However, the colour charts depicting the strat vortex (below) completely stump me. I wonder is there any where I could find a blog/article that explains how to interpret them? 

Sperrin, the X axis is the degree of latitude, so 0 is the equator and 90 the North Pole. The Y axis is from sea level (1000mb) right up through the atmosphere to 0mb pressure. The colours show the zonal speed at each level and whether they are positive zonal winds (red) or negative zonal winds (blue).

Therefore, if you look at 90 degrees North, it shows the zonal winds have reversed pretty much all the way through the atmosphere, this is a sign of a very weak polar vortex, you would normally expect deep reds at this time of the year.

Edited November 15, 2016 by mountain shadow

[Sperrin]

Ah right, cheers MS. Looking at it now in a whole new way! So a raging vortex would have lots of yellow/reds from sea level right up to the top of the atmosphere on the right hand side with blues in the centre? 

[bluearmy]

10 minutes ago, Sperrin said:

Ah right, cheers MS. Looking at it now in a whole new way! So a raging vortex would have lots of yellow/reds from sea level right up to the top of the atmosphere on the right hand side with blues in the centre? 

Not exactly but here is last december's chap

Edited November 15, 2016 by bluearmy

[Johnp]

1 hour ago, mountain shadow said:

Sperrin, the X axis is the degree of latitude, so 0 is the equator and 90 the North Pole. The Y axis is from sea level (1000mb) right up through the atmosphere to 0mb pressure. The colours show the zonal speed at each level and whether they are positive zonal winds (red) or negative zonal winds (blue).

Therefore, if you look at 90 degrees North, it shows the zonal winds have reversed pretty much all the way through the atmosphere, this is a sign of a very weak polar vortex, you would normally expect deep reds at this time of the year.

Thanks!  I finally understand these damn charts now!

[MattH]

1 hour ago, bluearmy said:

Not exactly but here is last december's chap

Ohh the stuff of nightmares that!...sends shudders down my spine at the thoughts and memories of last December all orchestrated, well primarily at least, by the 'raging beast' of Dec 15!

[Catacol]

Always good to see this going in the right direction. A bit of a clumsy tool I guess, but gives an overall feel for vortex happiness. 

[Dennis]

So this is a nice winter-start from December (SSW possible)

[Interitus]

On 11/3/2016 at 09:30, Glacier Point said:

OK, more precisely, NO_x pulled down from the layers above which bond with O₃ and facilitate additional complexes with chlorine and bromine both of which result in an endothermic reaction resulting in cooling.

NOx is a catalyst for O3/O2/O cycling, it doesn't permanently bond and it is also predominantly a null cycle involving no net O3 change with only a small fraction of ozone lost (via NO+O3 → NO2+O2 → NO2+O → NO+O2)  which requires free oxygen radicals produced by photolysis i.e. UV from sunlight - very little in polar night. Air pulled down from upper layers brings down increased ozone from the mid-latitudes in any case and max O3 typically reached towards the end of the winter. Chlorine and bromine remain overwhelmingly in unreactive reservoir forms until the presence of PSCs (polar stratospheric clouds) and water vapour aerosols form at already very low temperatures, typically below 195-198K (-78/-75°C) (with then reaction with the returning spring sunlight forming the basis of ozone hole theory). Endothermic reactions also need to be considered as unfavourable as requiring energy rather than producing cooling. The temperature of the vortex is a balance between radiative cooling exceeding solar warming (diabatic), causing the air to sink which produces some adiabatic counter warming with further adiabatic warming from wave driving. A reference which quantifies the impact of endothermic cooling would be welcome, but searches for such diabatic chemical kinetics is proving fruitless.