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chionomaniac

Stratosphere Temperature Watch

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Guest North Sea Snow Convection
I know this is only a forecast, but we have a major SSW on the cards! The mean zonal winds at 10 hPa are forecast to be easterly at T+192.

Because this is such a close thing it is worth waiting and watching over the coming days to see if this is maintained. However I will be keeping an eye on propagation of this vortex split down to lower levels. I have the 20 hPa level next firmly in the sights which is at present westerly by 6.25m/s at T+192.

Temps still show a good warming at 30hPa level

c

If (if) this trend is manitained downwards then arguably the present zonal spell could see the jet going south and those height rises coming on the back of it as go through the first part of February. Might sound early, and might be premature indeed, but if this is indeed a major event then high latitude blocking within the first half of Feb is not too far fetched.

Bit of a ramp I know - but this is already a much bigger event than the one initiated last year that took a month to do the job.

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So are we seeing warming right now, or is this still a predicted event?.

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If (if) this trend is manitained downwards then arguably the present zonal spell could see the jet going south and those height rises coming on the back of it as go through the first part of February. Might sound early, and might be premature indeed, but if this is indeed a major event then high latitude blocking within the first half of Feb is not too far fetched.

Bit of a ramp I know - but this is already a much bigger event than the one initiated last year that took a month to do the job.

Agreed. I have looked back at previous warmings. I think tundras 1 Jan 1985 SSW is the benchmark to hope for. The start of the warming is forecast for today or tomorrow with the central date (if it occurs) a week hence. I don't think the time lag is as long as I have previously thought so we should be on the look out for something in 2-3 weeks. That tends to fit in with GP's thoughts on the GWO thread. With other factors coming together at the same time then .........

If the winds reverse at 10hPa level greater than 10m/s and we get any reversal at 30hPa level then I would say that would be an extremely strong MMW. So there is a lot to keep an eye on in the run up to February.

c

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Guest North Sea Snow Convection
So are we seeing warming right now, or is this still a predicted event?.

The actual warming is just about to begin. The prediction first appeared several days ago and the signal has grown since then. It is not a question now IMO really whether there will be a warming, but how much of a warming there will be, and when it might affect our surface weather. Touch wood - prospects are looking increasingly promising.

But as chionomaniac says, we need to keep watching things progress over the next day or so to see how much reverse polarity can be achieved on the vortex from top to bottom. So not quite yet, but getting there in a nutshell.

Agreed. I have looked back at previous warmings. I think tundras 1 Jan 1985 SSW is the benchmark to hope for. The start of the warming is forecast for today or tomorrow with the central date a week hence. I don't think the time lag is as long as I have previously thought so we should be on the look out for something in 2-3 weeks. That tends to fit in with GP's thoughts on the GWO thread. With other factors coming together at the same time then .........

If the winds reverse at 10hPa level greater than 10m/s and we get any reversal at 30hPa level then I would say that would be an extremely strong MMW. So there is a lot to keep an eye on in the run up to February.

c

Hiya - good post. I think that is exactly the situation. As you say, there are other factors coming together that will assist. I notice on the model thread that GP's dominoes look well placed to tumble, with the Azores High increasingly weakened and displaced NW, The MJO has been heading for phase 8 in tandem with the GWO to phase 1. And I don't think that block to the NE is going to go far. Plenty to look out for! :o

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If I'm reading those graphs correctly then this warming is centred very near Greenland. In recent years when we've had a warming, they've tended to be centred over the other side of the pole - so if this comes off it could get really interesting.

Yes and todays latest NCEP stratospheric height forecasts look really promising as well, from 1hPa right down to 100hPa.

http://www.cpc.ncep.noaa.gov/products/stra...here/strat_a_f/

c

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Guest North Sea Snow Convection

I'm not a member or anything over there, but taken the liberty of copying this post over from TWO which I have seen about this Stratospheric warming and copied it onto here for people to see because I think it gives some excellent pointers, info and links as to what to look for regarding this event:-

I think you might find this recent Japanese paper usefulhttp://center.stelab.nagoya-u.ac.jp/cawses2005/PDF/yamazaki_koji.pdf

the authors explore the reasons why some SSW events do propogate down through to the Trop and others don't. I thought that if we "Strat fans" all had a look at the paper we might be able to decipher some signals that we could look out for during this event, and make some sort of tentative forecast

FWIW my reading of the paper suggests the following

  • some SSWs propogate -ive zonal wind anomalies down beyond 100/150 hPa @50-80N (Warm Trop SSWs)
  • some SSWs do not cause -ive zonal wind anomalies below 100 hPa @50-80N (Cold Trop SSWs)
  • Warm trop events with the sustained -ive zonal wind anomalies appear to result from EP fluxes with a more poleward orientation
  • wave 2 pattern planetary waves appear to enhance upward propogation in the growing stages of the SSW

So if we are hoping for a SSW event that can disrupt the PV and give us a greater chance of a HLBE ("Beast from the East/North") , then apparently we should be looking for enhanced upward wave 2 EP flux, with a poleward orientation.

Now I really hope that I've got that right, and if I have, then I think that the data shown on the third and bottom graphs of this page might offer us some grounds for optimism:-

http://strat-www.met.fu-berlin.de/cgi-bin/times?plot=fluxes&alert=1

I *think* that the diagram forecasts upward propogation of poleward orientated heat flux consistent with SSW events that do propogate downwards.

Edit: some other links for the "Straty community"

http://www.geog.cam.ac.uk/research/ep/ap/pwf.pdf

http://www.geog.cam.ac.uk/research/projects/stratospheretroposphere/stratospheretroposphere.png

http://www.ccpo.odu.edu/SEES/ozone/class/Chap_6/6_Js/6-14.jpg

Very much agree that there are grounds for optimism :)

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I'm not a member or anything over there, but taken the liberty of copying this post over from TWO which I have seen about this Stratospheric warming and copied it onto here for people to see because I think it gives some excellent pointers, info and links as to what to look for regarding this event:-

I think you might find this recent Japanese paper usefulhttp://center.stelab.nagoya-u.ac.jp/cawses2005/PDF/yamazaki_koji.pdf

the authors explore the reasons why some SSW events do propogate down through to the Trop and others don't. I thought that if we "Strat fans" all had a look at the paper we might be able to decipher some signals that we could look out for during this event, and make some sort of tentative forecast

FWIW my reading of the paper suggests the following:-

  • some SSWs propogate -ive zonal wind anomalies down beyond 100/150 hPa @50-80N (Warm Trop SSWs)
  • some SSWs do not cause -ive zonal wind anomalies below 100 hPa @50-80N (Cold Trop SSWs)
  • Warm trop events with the sustained -ive zonal wind anomalies appear to result from EP fluxes with a more poleward orientation
  • wave 2 pattern planetary waves appear to enhance upward propogation in the growing stages of the SSW

So if we are hoping for a SSW event that can disrupt the PV and give us a greater chance of a HLBE ("Beast from the East/North") , then apparently we should be looking for enhanced upward wave 2 EP flux, with a poleward orientation.

Now I really hope that I've got that right, and if I have, then I think that the data shown on the third and bottom graphs of this page might offer us some grounds for optimism:-

http://strat-www.met.fu-berlin.de/cgi-bin/times?plot=fluxes&alert=1

I *think* that the diagram forecasts upward propogation of poleward orientated heat flux consistent with SSW events that do propogate downwards.

Edit: some other links for the "Straty community"

http://www.geog.cam.ac.uk/research/ep/ap/pwf.pdf

http://www.geog.cam.ac.uk/research/projects/stratospheretroposphere/stratospheretroposphere.png

http://www.ccpo.odu.edu/SEES/ozone/class/Chap_6/6_Js/6-14.jpg

Very much agree that there are grounds for optimism :)

Yes already caught that! There are a few other good links from B in that thread too.

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I'm not a member or anything over there, but taken the liberty of copying this post over from TWO which I have seen about this Stratospheric warming and copied it onto here for people to see because I think it gives some excellent pointers, info and links as to what to look for regarding this event:-

its ok tamara - its not like being a racist - there are a few posters on here who are members on 'the other side' :)

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Guest North Sea Snow Convection
its ok tamara - its not like being a racist - there are a few posters on here who are members on 'the other side' :)

lol - I was being polite for stealing a post as I am a non member :)

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I just want to introduce myself, my name is Chris and I am from the U.S. (Langhorne, Pa.) which is located between Philadelphia and Trenton, NJ. I have been a reader for some time and I admire how you guys communicate with each other. Now on to my question; How will this possible stratosphere warming effect the U.S. preferably the East coast.

Thanks,

Chris

from the other side

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I just want to introduce myself, my name is Chris and I am from the U.S. (Langhorne, Pa.) which is located between Philadelphia and Trenton, NJ. I have been a reader for some time and I admire how you guys communicate with each other. Now on to my question; How will this possible stratosphere warming effect the U.S. preferably the East coast.

Thanks,

Chris

from the other side

Hi Chris, welcome to netweather and thanks on behalf of everyone here for your kind comments.

It is too early to say what the long term effects down the line will be here or in the U.S. Now, I am no expert in U.S. climatology, however stratospheric warmings often give rise to a negative AO. If blocking occurs around Greenland and a negative NAO develops then, if the right conditions prevail, I am sure the East coast of the US would benefit from cold outbreaks. I am sure that if you asked on Easternuswx someone will come along and give you a far better answer than I am able to provide.

Regards

c

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The charts look excellent this morning with the warming having now started as well.

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I have the 20 hPa level next firmly in the sights which is at present westerly by 6.25m/s at T+192.

c

And we have reversal forecast at 20hPa level

post-4523-1232352959_thumb.png

If the winds reverse at 10hPa level greater than 10m/s and we get any reversal at 30hPa level then I would say that would be an extremely strong MMW. So there is a lot to keep an eye on in the run up to February.

c

Latest at 10 hPa level is -14m/s!

post-4523-1232353112_thumb.png

The mean zonal wind forecast at T+192 at the 30 hPa is just 4.95m/s. We are very close to reversal here as well!

post-4523-1232353433_thumb.png

As this would be the first ever recorded MMW at the same time as a west QBO during a solar minimum one has to say that this is either a hoax or unprecedented!

Only time will show us which.

c

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Guest North Sea Snow Convection
The forecast looks very promising but we need to see a rise occuring here as soon as possible: http://ds.data.jma.go.jp/tcc/tcc/products/...e/pole30_n.html

Hopefully, it will start showing in the next day or two.

Karyo

It should. JMA is usually a little behind ECM forecasts - and this has been predicted and slowly upgraded over several days now. But we are very close, and need to keep everything crossed! NCEP/GFS forecasts have been bullish about this warming too.

Edit - I am wondering if that link has been updated for at least a few days. The warming is actually starting now already.

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It should. JMA is usually a little behind ECM forecasts - and this has been predicted and slowly upgraded over several days now. But we are very close, and need to keep everything crossed! NCEP/GFS forecasts have been bullish about this warming too.

Edit - I am wondering if that link has been updated for at least a few days. The warming is actually starting now already.

Yes, it has been updated - i visit it every day! I often find that it doesn't directly correspond with the ECM forecasts but picks up the same trend. For example, this can be seen from November's minor warming.

Anyway, as you say it should show a steep rise in the next couple of days!

Karyo

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Guest North Sea Snow Convection
Yes, it has been updated - i visit it every day! I often find that it doesn't directly correspond with the ECM forecasts but picks up the same trend. For example, this can be seen from November's minor warming.

Anyway, as you say it should show a steep rise in the next couple of days!

Karyo

Just an observation, but there is a difference of at least 10 degrees on the present temp between the ECM and JMA. It almost looks as though the JMA depicts the current temp state and doesn't forecast ahead, but even then strange that the readings are so different for the present time as well!

I usually rely mostly on the ECM forecasts, and must admit I haven't looked at the JMA link for a long time :lol:

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Just an observation, but there is a difference of at least 10 degrees on the present temp between the ECM and JMA. It almost looks as though the JMA depicts the current temp state and doesn't forecast ahead, but even then strange that the readings are so different for the present time as well!

I usually rely mostly on the ECM forecasts, and must admit I haven't looked at the JMA link for a long time :lol:

It could be the difference between this

post-4523-1232364101_thumb.png

and this

post-4523-1232364130_thumb.png

The first is the average between 65N and 90N, the second is at the NP only.

Oh and link to all this type of info

http://www.cpc.ncep.noaa.gov/products/stra...re/temperature/

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The forecast looks very promising but we need to see a rise occuring here as soon as possible: http://ds.data.jma.go.jp/tcc/tcc/products/...e/pole30_n.html

Hopefully, it will start showing in the next day or two.

Karyo

yes, I will feel more confident in a blocking spell WHEN that rises and gets above zero and stays there for some time.

I am still uncertain that any form of major blocking, be it north east or north west of the Uk, is going to occur before early, possibly even mid February.

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It's the 30 hPa level that is catching my eye. The lower down the stratosphere we see these changes, the more likely they are to be influential.

post-4523-1232366488.gif

post-4523-1232366566.gif

Even now the warming is propagating to the 50 hPa level

post-4523-1232366616.gif

c

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As this would be the first ever recorded MMW at the same time as a west QBO during a solar minimum one has to say that this is either a hoax or unprecedented!

Only time will show us which.

c

Yes you are quite right this is unprecedented since these events started to be recorded. As a result we therefore have a lower level of confidence as to what the likely outcome will be!

However, as someone who has been watching this for the past three years and has looked at the past history of the various winter warmings I do think that stratospheric temperatures do give a truly valid indicator of the potential for NH troposheric cooling.

This particular event does appear to have the makings of a significant MWW - and if it does work its way through then I would expect the timing to be about the second week of February. However this is rather getting ahead of things as we have yet have to see whether MWW + W QBO + Low Solar will actually produce a noticeable event.

The real excitement here is that we actually have the opportunity to watch this event progress and (almost in real time) see how it eventually pans out. It is all part of the learning process.

MM

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The theme continues with the forecast of the MMW. The easterly winds have now reached the 30 hPa level with reversal occurring here. If this was to occur as predicted I would classify this as an extremely strong MMW.

post-4523-1232437934_thumb.png

And there almost seems like a glitch delaying the 10 hPa cooling. All good.

post-4523-1232437921_thumb.png

c

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post-7011-1232439966_thumb.png

Great to see the warming now actually taking place along with the reduction in zonal winds.

Easterly winds at 30hpa, this February could be one to remember. It will be interesting to see what the Met have to say in their winter update on the 22nd of Jan.

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