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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
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Posted
  • Location: Cuijk, Noord-Brabant, The Netherlands
  • Weather Preferences: Any extreme wheater event.
  • Location: Cuijk, Noord-Brabant, The Netherlands

Especially the drop in solar activity over the past few months is spectacular. What would be the consequence of this event?

Ap.gif

Edited by snowball
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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

What sort of weather conditions does that chart show for the UK?

It is very much a stratospheric chart that could lead to a SSW.

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Posted
  • Location: Catchgate, Durham,705ft asl
  • Location: Catchgate, Durham,705ft asl

It is very much a stratospheric chart that could lead to a SSW.

If that chart verified (big if!)

Is this the sort of thing we would be seeing on the NP 30mb chart?

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Posted
  • Location: Eccles, Greater manchester.
  • Location: Eccles, Greater manchester.

I was wondering if anybody could tell me what ,apart from human activity,affects ozone levels in the atmosphere in the arctic.

Edited by greybing
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Posted
  • Location: Lincs
  • Location: Lincs
Posted · Hidden by coldwinter, January 7, 2012 - No reason given
Hidden by coldwinter, January 7, 2012 - No reason given

Sorry to be a noob, but could you explain how to interpret the 30mb geopotential height chart attached by sebastian.

Thanks.

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Posted
  • Location: @scotlandwx
  • Weather Preferences: Crystal Clear High Pressure & Blue Skies
  • Location: @scotlandwx

Sorry to be a noob, but could you explain how to interpret the 30mb geopotential height chart attached by sebastian.

Thanks.

Bosh !

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Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

Just out of interest do we also experience stratospheric warming events over the south pole and antarctica? - if so do these produce powerful antartic shots of weather into the south of chile and argentina as well as new zealand?

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Posted
  • Location: Cuijk, Noord-Brabant, The Netherlands
  • Weather Preferences: Any extreme wheater event.
  • Location: Cuijk, Noord-Brabant, The Netherlands

Is this the sort of thing we would be seeing on the NP 30mb chart?

Yes! It looks pretty impressive.

Edited by snowball
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Posted
  • Location: Reigate, Surrey
  • Location: Reigate, Surrey

I was wondering if anybody could tell me what ,apart from human activity,affects ozone levels in the atmosphere in the arctic.

Ozone is created through a photochemical reaction (i.e. driven by the sun) on oxygen molecules which produces single oxygen atoms which can then combine with other oxygen molecules to produce ozone. One of the possible things that can increase ozone levels therefore is extensive snow cover (in areas receiving sunlight - i.e. tending to be south of the pole) since additional solar radiation is then reflected back into the upper atmosphere strengthening the reaction.

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Just out of interest do we also experience stratospheric warming events over the south pole and antarctica? - if so do these produce powerful antartic shots of weather into the south of chile and argentina as well as new zealand?

Theres only ever been one recorded SSW in the Southern Hemisphere in terms of a major warming, and this apparently hasn't even been fully understood, apparently theres much more interaction between orography and Rossby waves in the NH and this is one of the key components for a SSW.

Edited by nick sussex
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Posted
  • Location: st albans
  • Location: st albans

Each day we get closer to a forecast SSW. However, if day 10 is close to how ecm sees it, not sure the upper levels of the strat over the pole can recover a meaningful vortex this winter.

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Posted
  • Location: Carryduff, County Down 420ft ASL
  • Location: Carryduff, County Down 420ft ASL

Each day we get closer to a forecast SSW. However, if day 10 is close to how ecm sees it, not sure the upper levels of the strat over the pole can recover a meaningful vortex this winter.

The warming at 10hpa is off the scale as Nick mentions in the MOT, if this can't induce an SSW then I'm not sure what can. The chances of an SSW event must be higher now I would have thought.

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

The warming at 10hpa is off the scale as Nick mentions in the MOT, if this can't induce an SSW then I'm not sure what can. The chances of an SSW event must be higher now I would have thought.

If we look at T240 at the lower level 100hPa we can see that although the vortex has not yet been split by this,it is on the move away from Greenland and towards Siberia,Compare these 2 images

T12hrs.post-2026-0-87822200-1325927363_thumb.gi T240hrs.post-2026-0-60110600-1325927384_thumb.gi

The flow turning more North of West later in response to this,and this is now being modelled in 500hPa forecasts -see Mod.thread.

So a vortex displacement for now but further damage could well be done to the PV as more wavebreaking occurs down the line.

Edited by phil n.warks.
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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

I can't see that a SSW will be avoided going by todays ECM forecast - it would probably occur day 11 or 12 (subject to verification). The GFS is also on board so very promising indeed.

The 10 hPa level has forecast mean zonal winds of 6.23m/s at day 10 and with the warming in mid flow at this level further displacement is likely to occur.

post-4523-0-46570100-1325927920_thumb.gi

Interestingly the GFS extended forecasts are hinting at total disintergration of the vortex following the displacement. We are probably looking towards the end of Jan for this to feedback tropospherically. We may be lucky enough to see something sooner as a direct consequence of the displacement.

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Posted
  • Location: Worcestershire
  • Weather Preferences: Forecaster Centaurea Weather
  • Location: Worcestershire

I think Tokyo will be issuing a Stratalert in the coming days, based on the ECM diagnostics being a day behind.

If there is reasonable agreement between ECM and GFS, we will have a third warming event shortly after the day 10. This one of a totally different magnitude and focussed directly over the pole.

post-2478-0-61154000-1325927980_thumb.jp

That would take the 10hPa temperature up to 0 C (bearing in mind the Berlin site scale only goes to -20C).

So we have one minor warming event which may be impacting the tropopause in the next 10 days, a second possible sudden stratospheric warming event in 9 days time and then shortly after a massive warming directly over the pole. That spells Major Mid Winter Warming to me, and as Bluearmy states, hard to see a way back for the stratospheric vortex this side of the summer given that angular momentum has been so high this winter and a planetary AP index on the floor, not to mention anomalously warm surface temperatures across the Arctic leading to increased heat flux.

If it comes off anywhere near forecast, this will have major implications for the entire circulation pattern across the globe and we should see feedback loops being set up in the tropics leading to enhanced deep convection around the Dateline, further locking a strong -AO/-NAO pattern.

In so far as how this might impact the UK, this is pure speculation but I note that the tendency for troughing into Europe and the eastern US already and this would be the logical route for cold to be bled from the pole. Also interesting in the mix is that what remains of the vortex could be shifted southwards towards Scandinavia.

Interestingly the GFS extended forecasts are hinting at total disintergration of the vortex following the displacement. We are probably looking towards the end of Jan for this to feedback tropospherically. We may be lucky enough to see something sooner as a direct consequence of the displacement.

Taking mid Jan as our 'starting' pistol, conventional thinking places us in early Feb for tropospheric impact. However, might be quicker given the rapid 'shock wave' type response to that warming forecast 18th January. Might be a bit of a challenge to actually pinpoint the official start of this one, given that mean zonal winds may have reverse before this third warming event.

Edited by Glacier Point
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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

All very interesting GP and fits in very well with your forecast. I suspect that the ball is rolling now and that there will be no stopping it now.

I am very intrigued as to where blocking will set up later. But whatever occurs I think that the jet stream will divert south.

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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

I think Tokyo will be issuing a Stratalert in the coming days, based on the ECM diagnostics being a day behind.

So we have one minor warming event which may be impacting the tropopause in the next 10 days, a second possible sudden stratospheric warming event in 9 days time and then shortly after a massive warming directly over the pole. That spells Major Mid Winter Warming to me, and as Bluearmy states, hard to see a way back for the stratospheric vortex this side of the summer given that angular momentum has been so high this winter and a planetary AP index on the floor, not to mention anomalously warm surface temperatures across the Arctic leading to increased heat flux.

If it comes off anywhere near forecast, this will have major implications for the entire circulation pattern across the globe and we should see feedback loops being set up in the tropics leading to enhanced deep convection around the Dateline, further locking a strong -AO/-NAO pattern.

Thank you GP.

It sounds very interesting and promising. However, I can't help but worry about the effect this may have on the Arctic ice. All this cold escaping out of the arctic and warm plumes reaching the area may mean a terrible summer melt! :-(

Karyo

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Posted
  • Location: Hampstead / Cambridge
  • Location: Hampstead / Cambridge

= bring on february ! Is this warming worse than that which produced the easterlies of feb 2009?

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Posted
  • Location: Caldercruix, North Lanarkshire - 188m asl
  • Location: Caldercruix, North Lanarkshire - 188m asl

Thank you GP.

It sounds very interesting and promising. However, I can't help but worry about the effect this may have on the Arctic ice. All this cold escaping out of the arctic and warm plumes reaching the area may mean a terrible summer melt! :-(

Karyo

On the plus side, the polar bears can come live here in the UK when we freeze solid for a couple of months as a result of these events.

(not to be taken literally ofcourse, just a wee mood lightener)

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Posted
  • Location: Epsom, Surrey, 100 Meters above sea level
  • Weather Preferences: Anything Extreme
  • Location: Epsom, Surrey, 100 Meters above sea level

so IF we do indeed get either a displacement, or a SSW , when are we likely to actually feel the effects here in the UK, I read this forum daily, and from what I can gather it would be somewhere between 20-30 days after a SSW that we'd feel any effects ?? given that IF we do get a SSW mid month, then I'm assuming it's effects wouldn't be felt in the UK until mid Feb at best ??

Which is just the wrong side of winter for it to really beneficial in terms of producing significant snowfall, that wouldn't melt under a strong sun given the time of year ??

so lets hope we DO get a SSW, and lets hope everything falls into place, we get a good few weeks of snowfall UK wide, and on the days where it doesn't snow, let's hope it's overcast and cold, so the snow doesn't melt :-)

Either way it's looking promising, and I'd take anything right now, other than the bland zonality, interspersed by never ending high pressure to the SW of the UK / over the UK / or to the South East of the UK, and low's passing from W to the NE , which feels like it's been going on FOR EVER

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

so IF we do indeed get either a displacement, or a SSW , when are we likely to actually feel the effects here in the UK, I read this forum daily, and from what I can gather it would be somewhere between 20-30 days after a SSW that we'd feel any effects ?? given that IF we do get a SSW mid month, then I'm assuming it's effects wouldn't be felt in the UK until mid Feb at best ??

Which is just the wrong side of winter for it to really beneficial in terms of producing significant snowfall, that wouldn't melt under a strong sun given the time of year ??

so lets hope we DO get a SSW, and lets hope everything falls into place, we get a good few weeks of snowfall UK wide, and on the days where it doesn't snow, let's hope it's overcast and cold, so the snow doesn't melt :-)

Either way it's looking promising, and I'd take anything right now, other than the bland zonality, interspersed by never ending high pressure to the SW of the UK / over the UK / or to the South East of the UK, and low's passing from W to the NE , which feels like it's been going on FOR EVER

It really depends on whether we see a major warming, the time lag can be much shorter with that, if we get a reverse in the zonal winds then that could be seen within a week.

In terms of a minor warming these often take much longer to feed through, looking at the current output this looks to be currently effected by one of the previous weaker warming events.

It's not an exact science and for this reason expect the unexpected!

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