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AS you post earlier chio it is probably a victim of its own success. How to keep it to the standard of the last 2-3 years now it is so popular is hard to see what anyone can do without making it a restricted access. Chat with Paul perhaps?

 No definitely not - we may miss out on the calibre of posters such as Recretos, Sebastiaan and anthonym and others if that is the case. So we need to have it open but perhaps we will need stricter moderating to prevent going off on a tangent.

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 No definitely not - we may miss out on the calibre of posters such as Recretos, Sebastiaan and anthonym and others if that is the case. So we need to have it open but perhaps we will need stricter moderating to prevent going off on a tangent.

 

I would agree with that suggestion, good luck to those with the moderating task though. Another way might be to appeal to everyone to keep to a strict code, most folk that dip in here do so, like me, to learn so that appeal should meet with more agreement than whenever the team try it in the model thread?

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I think being one of the 'culprits' that derailed but wanted it back on topic I'll ensure I'll self moderate to remain on topic or indeed just read and not post Posted Image , only agenda is a believed link.  I think as the techs post more it'll settle down too as there'll be lot's to read and digest.  So eyes down.

 

BFTP

Edited by BLAST FROM THE PAST
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Just to get back to the monitoring.

Early days in the season yet but a brief pause in the cooling over the pole.

post-2026-0-74613400-1382693938_thumb.gi

 

We have had an Asian mountain torque event which, if i am reading things correctly, created the current wave 1 activity currently evident.

post-2026-0-04204200-1382694155_thumb.gi

 

post-2026-0-05836800-1382694090_thumb.gipost-2026-0-82646800-1382694098_thumb.gi

 

however from the last image it looks like this will cool out by day 5 as the vortex then continues to strenghten as one would expect at this stage of the year.

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=u&lng=eng#fig1

 

Mean  zonal wind forecast increasing at 1hPa and gradually filtering down through he next 10 days.

Edited by phil nw.
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Can not remember seeing such a prolonged and elevated  Asian mountain torque

I would not be surprised to see the effects of this filter down into the synoptic charts

over the coming weeks.

I think most on here are aware that you can have a strong vortex along side

northern blocking (HLB's).

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Can not remember seeing such a prolonged and elevated  Asian mountain torque

I would not be surprised to see the effects of this filter down into the synoptic charts

over the coming weeks.

I think most on here are aware that you can have a strong vortex along side

northern blocking (HLB's).

One has to think that with such a prolonged torque that it would be very surprising not to have some stratospheric knock on effect. I would normally expect to see some type of increase in wave 1 activity as a result and yes we have seen some, but perhaps a bit more than this could be expected.

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although gfs trop fi is to be avoided, i note the op and control both develop a split vortex in two weeks time. at the same time there is a warming of sorts over ne asia at 10hpa.  i've been away for a week so not been following too closely. this may be 'old news'.

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Chiono,Recretos and co, why not an early SSW this year? + w QBO and solar max.why do you think we may have a late SSW..I have a theory we have had a very cold summer arctic so we may have a sudden increase in the warmth up there in the arctic as its been so cold up there during summer months

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Chiono,Recretos and co, why not an early SSW this year? + w QBO and solar max.why do you think we may have a late SSW..I have a theory we have had a very cold summer arctic so we may have a sudden increase in the warmth up there in the arctic as its been so cold up there during summer months

Nothing can be ruled out, John, but when looking at all likelihoods it is extremely unlikely to get a SSW in November. Remember, to achieve a technical SSW we need to see mean zonal mean winds reverse at 10 hPA at 60ºN. Even in Nov 1996 (which is sometimes reported as a SSW) the mean zonal winds never reversed - and this was a eQBO year. 

 

What can possibly occur though is tropospheric wave breaks into the lower strat similar to 2009. Again another tall order.

 

SSW's have occured later in the season in some close matching years though and one of my favourite analogue winters for this winter is 1978/79. That year a CW and SSW were reported. The forecasted increase in vortex strength for November was actually something that I was expecting to see. The Asian MT is such a significant one though that we need to keep an eye on whether there is any lower stratospheric vortex effect. Autumn 2009 showed us that the lower stratospheric vortex is vulnerable to tropospheric attack before the main bulk of the polar stratosphere has cooled sufficiently and the upper vortex strength transfers its power downwards towards the trop.

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Nothing can be ruled out, John, but when looking at all likelihoods it is extremely unlikely to get a SSW in November. Remember, to achieve a technical SSW we need to see mean zonal mean winds reverse at 10 hPA at 60ºN. Even in Nov 1996 (which is sometimes reported as a SSW) the mean zonal winds never reversed - and this was a eQBO year. What can possibly occur though is tropospheric wave breaks into the lower strat similar to 2009. Again another tall order.SSW's have occured later in the season in some close matching years though and one of my favourite analogue winters for this winter is 1978/79. That year a CW and SSW were reported. The forecasted increase in vortex strength for November was actually something that I was expecting to see. The Asian MT is such a significant one though that we need to keep an eye on whether there is any lower stratospheric vortex effect. Autumn 2009 showed us that the lower stratospheric vortex is vulnerable to tropospheric attack before the main bulk of the polar stratosphere has cooled sufficiently and the upper vortex strength transfers its power downwards towards the trop.

So Chiono, why is this year harder to call for a SSW than last year?, we have had a very cold pool early, isn't it possible we could have an early warming? Is The early wave breaking + MT normal?and could the initial effect on the PV be more profound. Maybe this could be an earlier sign for a SSW than what you were originally thinking? Or am I way ooff the mark with this train of thought? Edited by John Badrick
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One has to think that with such a prolonged torque that it would be very surprising not to have some stratospheric knock on effect. I would normally expect to see some type of increase in wave 1 activity as a result and yes we have seen some, but perhaps a bit more than this could be expected.

Wave2 is on the increase. Maybe that's what the prolonged MT is stirring up as well.
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still some warming showing in FI looks stronger on the 0z than the 6z

 

0z

 

Posted Image0z.pngPosted Image0 z.png

 

6z

 

Posted Imagenpst30CAHWY9Z4.pngPosted Image6z.png

 

this is a link I put in the strat thread last night its an article on America but at the bottom he talks about the possibility of an early SSW being triggered

 

http://weatherworksinc.com/early-November-snow-threat

Looking at where the high ozone content is , and where the warming is actually talking place, I wonder weather that has any baring on where the vortex disruption will take place , because if there was a split for instance where the warming is occurring , then I don't think it will affect the uk too much , as the displaced vortex will sit either side of the warming , which will be toward Greenland and the other toward Russia , which will most likely result in energy spilling towards us from greenlands. But with that in mind with two pieces of vortex set up , you will also have areas of high pressure , most likely in between those vortex segments , so one might expect high pressure from say just east of Iceland , over across to Norway up towards scandi maybe ? . . . . Indeed this monitoring over the next 10 days or so, but may give ppl an early shock cold belting !!
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Nothing can be ruled out, John, but when looking at all likelihoods it is extremely unlikely to get a SSW in November. Remember, to achieve a technical SSW we need to see mean zonal mean winds reverse at 10 hPA at 60ºN. Even in Nov 1996 (which is sometimes reported as a SSW) the mean zonal winds never reversed - and this was a eQBO year. 

 

What can possibly occur though is tropospheric wave breaks into the lower strat similar to 2009. Again another tall order.

 

SSW's have occured later in the season in some close matching years though and one of my favourite analogue winters for this winter is 1978/79. That year a CW and SSW were reported. The forecasted increase in vortex strength for November was actually something that I was expecting to see. The Asian MT is such a significant one though that we need to keep an eye on whether there is any lower stratospheric vortex effect. Autumn 2009 showed us that the lower stratospheric vortex is vulnerable to tropospheric attack before the main bulk of the polar stratosphere has cooled sufficiently and the upper vortex strength transfers its power downwards towards the trop.

 

 

 

 

A lot has to do with definition though and after mentioning Nov 1996 I went to check where the date had come from as indeed the GDAS cross-sections don't quite show 10mb 60°N -ve zonal wind though a large negative anomaly.

But with EOFs used by Baldwin et al, it had a -ve NAM of -2.05 as shown in the Martineau animations - http://p-martineau.com/ssw-animations/

 

The NCEP reanalysis shows that mean -ve zonal winds dominated the mid and lower strat and importantly, into the top of the troposphere

post-2779-0-16144800-1382876971_thumb.gi

 

and the GDAS GPH anomaly chart appears to show the mountain torque wave activity at the end of October and early November lead to vortex displacement towards the end of November which is followed by a classic instant tropospheric response and also a longer tail through December.

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_1996.gif

 

That said I hesitated to use the term SSW as this is a very different beast with at the time of displacement positive temperature anomalies only from 30mb downwards and negative temperature anomalies at 10mb and above

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_1996.gif

 

Indeed the strat vortex strengthened to lower levels through the rest of the winter, but meanwhile at ground level the initial disturbed lower vortex may have been in part responsible for the prolonged spells -ve AO until the second half of January, and it was the major strat event that winter (as seen in this chart of AO and CET anomaly)

 

post-2779-0-72539300-1382881703_thumb.gi

 

Sometimes the classifications can lead to the baby being thrown out with the bathwater!

Edited by Interitus
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Gfs fi is continuing to raise strat temps the other side of the pole from asia across to canada. fi trop runs are continually producing arctic ridging in areas which will promote furtther wave 1 activity. We may well see this signal muted once higher res trop modelling gets a handle and cranks up the vortex. However, to say that the next month will simply see the strat and trop vortices strengthening as per usual november is possibly a tad premature. There is more interest than i would expect at this time of year. Full ecm strat suite gets going this friday though the info is generally available now if you can trawl around the data.

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The attack on the stratosphere continues...wave 1 activity expected to increase in 10 days combined with an increase in wave 2 activity. Is this combined effort the reason why there's a credible rise in temperatures forecast for the other side of the north pole in a couple of weeks? Hopefully we get a minor warming out of this and we see a situation similar to early December last year, though with us being on the right side of blocking this time!

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actually, it looks as though those will drop sharply to average over the next few days. any subsequent warming over the other side of the pole looks to then displace the core back towards west siberia which would allow a gentle drift back above average though nothing special. a few years ago we saw these small warmings disrupt the vortex setting up through the autumn which helped lead to a cold late nov and dec. i doubt we should read too much into that for the time being.

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actually, it looks as though those will drop sharply to average over the next few days. any subsequent warming over the other side of the pole looks to then displace the core back towards west siberia which would allow a gentle drift back above average though nothing special. a few years ago we saw these small warmings disrupt the vortex setting up through the autumn which helped lead to a cold late nov and dec. i doubt we should read too much into that for the time being.

Would agree with Nick's assessment here. The forecasts suggest a minor warming downstream from Asia - this is minor and at present hardly affecting the increasing strength that is building in the vortex.

 

At 10 hPa at the end of the 00Z we see a cold establishing vortex for November with any wave activity hardly even 'kissing' the surf zone.

 

post-4523-0-98984800-1383121258_thumb.pn

 

The vortex below this wobbles slightly but no great disruption.

 

The forecast shape and position of the vortex is starting to match the November analogue seen in the first post at 30 hPa.

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Would agree with Nick's assessment here. The forecasts suggest a minor warming downstream from Asia - this is minor and at present hardly affecting the increasing strength that is building in the vortex.

 

At 10 hPa at the end of the 00Z we see a cold establishing vortex for November with any wave activity hardly even 'kissing' the surf zone.

 

Posted Imageviewimage.png

 

The vortex below this wobbles slightly but no great disruption.

 

The forecast shape and position of the vortex is starting to match the November analogue seen in the first post at 30 hPa

 

 

 

Does this not bode well for a SSW?

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