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chionomaniac

Stratosphere Temperature Watch

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Guest North Sea Snow Convection

Last winter took more than one bite before the warming fully propagated down to the surface. Memories play tricks and in fact the initial warming surge timewise was not as different as expressed and suggested yesterday. And it followed up with two more. The third and final one was at the end of February. (Tried to insert a link to show this, but has not worked for some reason)

It depends how the forecast unravels over the next day or two, and if the 30mb level can stretch a bit further,but a full warming to all levels is probably yet to come, and like last year it may take its time. Perhaps taking that view though, any advance on timing can be seen as a bonus.

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Last winter took more than one bite before the warming fully propagated down to the surface. Memories play tricks and in fact the initial warming surge timewise was not as different as expressed and suggested yesterday. And it followed up with two more. The third and final one was at the end of February. (Tried to insert a link to show this, but has not worked for some reason)

It depends how the forecast unravels over the next day or two, and if the 30mb level can stretch a bit further,but a full warming to all levels is probably yet to come, and like last year it may take its time. Perhaps taking that view though, any advance on timing can be seen as a bonus.

hi Tamara,

i think last year's first warming was not reflected much on the 30hpa level hence we had to wait for the 2nd and 3rd to see the results. This year, the warming is also expected to affect the 30hpa so fingers crossed.

I am also hoping for further episodes of warming during February so as to see a cold start to spring.

Karyo

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Guest North Sea Snow Convection
hi Tamara,

i think last year's first warming was not reflected much on the 30hpa level hence we had to wait for the 2nd and 3rd to see the results. This year, the warming is also expected to affect the 30hpa so fingers crossed.

I am also hoping for further episodes of warming during February so as to see a cold start to spring.

Karyo

Hi Karyo

Yes, there is some truth in that. I have a link for last winters stratospheric temperature record from the Berlin site, and keep trying to upload it, but it won't let me. Grr! :lol:

A good comparison could be made (if anyone else can be successful than me!).

I maybe being a bit over cautious, but have seen expert thought expressed as well as my own, that this may take a couple of attempts. However there is no doubt that the forecasted rise at the 30hpa level is higher than the corresponding response on the initial wave last year. And the fact that this has been extended today is a further improvement on that.

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Last winter took more than one bite before the warming fully propagated down to the surface. Memories play tricks and in fact the initial warming surge timewise was not as different as expressed and suggested yesterday. And it followed up with two more. The third and final one was at the end of February. (Tried to insert a link to show this, but has not worked for some reason)

It depends how the forecast unravels over the next day or two, and if the 30mb level can stretch a bit further,but a full warming to all levels is probably yet to come, and like last year it may take its time. Perhaps taking that view though, any advance on timing can be seen as a bonus.

Yep:

post-4523-1231693799.gif

Let's just hope that this year's forecast warming is a whammy in one go - is it looking much more intense? :lol:

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Guest North Sea Snow Convection
Yep:

Let's just hope that this year's forecast warming is a whammy in one go - is it looking much more intense? :lol:

thanks for that map

As post above - it is looking more intense in terms of being predicted to propagate quicker. :D

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Hi Karyo

Yes, there is some truth in that. I have a link for last winters stratospheric temperature record from the Berlin site, and keep trying to upload it, but it won't let me. Grr! :cc_confused:

A good comparison could be made (if anyone else can be successful than me!).

I maybe being a bit over cautious, but have seen expert thought expressed as well as my own, that this may take a couple of attempts. However there is no doubt that the forecasted rise at the 30hpa level is higher than the corresponding response on the initial wave last year. And the fact that this has been extended today is a further improvement on that.

ah but, remember it is a forecast, like I said a little way above, forecasts, as I know from experience do not always come off

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ah but, remember it is a forecast, like I said a little way above, forecasts, as I know from experience do not always come off

It's always a good practice to be cautious with forecasts in general. However, the stratospheric ones have a good rate of accuracy and success. Last year's events were forecasted very well with only minor changes.

Besides, this stratospheric warming event is expected to begin in a couple of days, so the margin or error is very small.

Karyo

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Guest North Sea Snow Convection

I've already expressed qualifying statements about this event a few times very recently so I'm not sure that another cautionary advisory is needed tbh. Certainly not for me personally anyway.

That said, I agree with you what you say Karyo - especially in view of the recent sustained strong mountain torque event which would validate the warming occuring. :cc_confused:

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Hi Karyo

Yes, there is some truth in that. I have a link for last winters stratospheric temperature record from the Berlin site, and keep trying to upload it, but it won't let me. Grr! :cc_confused:

A good comparison could be made (if anyone else can be successful than me!).

I maybe being a bit over cautious, but have seen expert thought expressed as well as my own, that this may take a couple of attempts. However there is no doubt that the forecasted rise at the 30hpa level is higher than the corresponding response on the initial wave last year. And the fact that this has been extended today is a further improvement on that.

Are these the ones for comparison purposes?

Last year (ignore the red circle - I borrowed it!)

post-4523-1232121031_thumb.jpg

This year

post-4523-1232121071_thumb.png

c

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Guest North Sea Snow Convection
Are these the ones for comparison purposes?

Last year (ignore the red circle - I borrowed it!)

This year

c

Thank you kind sir! Yes, those are the one's I was having some technophobe moments with this morning - for some reason they wouldn't paste on :cc_confused:

It can clearly be seen comaparing those two charts that the forecast for the 30mb level is predicted much higher today by ECM for this years expected warming than the level reached on the first corresponding surge last Jan. Assuming validation, that should make some difference in terms of impact on the PV IMO*forecasting caveat inserted just in case*

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Thank you kind sir! Yes, those are the one's I was having some technophobe moments with this morning - for some reason they wouldn't paste on :cc_confused:

It can clearly be seen comaparing those two charts that the forecast for the 30mb level is predicted much higher today by ECM for this years expected warming than the level reached on the first corresponding surge last Jan. Assuming validation, that should make some difference in terms of impact on the PV IMO*forecasting caveat inserted just in case*

It seems that this warming has been forecast for an age but hasn't even occurred yet! Every day we seem to get a little bit closer to a technical MMW but I am waiting for the door to be slammed shut before we get there. However this, as you say, is still an impressive temperature surge and I will put up the latest NCEP charts for comparison purposes.

Firstly the impressive warming at the pole (10 hPa). It's probably not often we will see a chart like this so something to cherish. T+192:

post-4523-1232122870.gif

Next the warming so far at the 30 hPa level. T+240

post-4523-1232122984.gif

And both vortex strength charts:

post-4523-1232123065.gif

post-4523-1232123096.gif

These have changed to a slightly more favourable warming in the last 24hrs, so hopefully that trend continues.

c

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And again we edge ever closer. Surely, if these forecasts are right, this can only go one way now.

Look at the mean zonal winds. The 10 hPa zonal mean wind anomaly edges ever closer to easterly:

post-4523-1232183254_thumb.png

Look at the all the levels mean zonal winds forecast T+192:

Yesterday

post-4523-1232183344_thumb.png

Today

post-4523-1232183367_thumb.png

Edging in the right direction. Even if we don't get that technical MMW, the vortex is still slowing down dramatically throughout the whole height of the stratosphere, and this is bound to have tropospheric implications further down the line!

This link shows the vortex at each level at T+192. The mean temp and zonal wind anomalies are in the bottom right . For the winds red is net easterly and good to see. Now down between 7-10 hPa.

http://strat-www.met.fu-berlin.de/cgi-bin/...p;forecast=f192

c

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well hopefully that would be the icing on the cake for the winter. sure we've had a cold anticylonic december, january so far has given some areas 3 days of lying snow(here) maybe a cold february with some more appreciable lasting snow to top it all off for all areas?

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Guest North Sea Snow Convection
And again we edge ever closer. Surely, if these forecasts are right, this can only go one way now.

Edging in the right direction. Even if we don't get that technical MMW, the vortex is still slowing down dramatically throughout the whole height of the stratosphere, and this is bound to have tropospheric implications further down the line!

This link shows the vortex at each level at T+192. The mean temp and zonal wind anomalies are in the bottom right . For the winds red is net easterly and good to see. Now down between 7-10 hPa.

http://strat-www.met.fu-berlin.de/cgi-bin/...p;forecast=f192

c

The forecast chart has had this strong warming predicted consistently for at least three/four days now, and has upgraded each day its potential. And we have reached the bottom of the start of that ladder on the forecast chart moreorless at t0 now. Don't want to jinx the forcast at this final stage, but if it is right then the effect on the vortex will certainly be a fair bit more than has been believed recently. The 30hpa chart has been edging the predicted peak slowly higher and has nudged a bit extra again this morning. The 10hpa warming has, if anything, taken its peak further off the chart. Be interesting to see how far the dip goes the other side. The zonal wind forecast has also, as you suggest, improved a bit with each days update

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The forecast chart has had this strong warming predicted consistently for at least three/four days now, and has upgraded each day its potential. And we have reached the bottom of the start of that ladder on the forecast chart moreorless at t0 now. Don't want to jinx the forcast at this final stage, but if it is right then the effect on the vortex will certainly be a fair bit more than has been believed recently. The 30hpa chart has been edging the predicted peak slowly higher and has nudged a bit extra again this morning. The 10hpa warming has, if anything, taken its peak further off the chart. Be interesting to see how far the dip goes the other side. The zonal wind forecast has also, as you suggest, improved a bit with each days update

Should be far less fall than rise if previous warmings are anything to go by.

post-4523-1232190207_thumb.png

Only 5.88m/s to go and we have a MMW. Not bad when you consider that a couple of days ago the mean zonal wind at 10hPa was close to 70m/s.

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Guest North Sea Snow Convection
Should be far less fall than rise if previous warmings are anything to go by.

post-4523-1232190207_thumb.png

Only 5.88m/s to go and we have a MMW. Not bad when you consider that a couple of days ago the mean zonal wind at 10hPa was close to 70m/s.

I understand the implications of zonal wind anomalies fully, and can see whether they are increasing or decreasing but how much of a difference is that in real terms? If you understand what I mean by that!

Is it that close that it virtually qualifies as a MMW - and where do you get that figure from? Sorry if I'm having a blond moment lol, but that calculation is a part that I am not fully clear about. :)

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I understand the implications of zonal wind anomalies fully, and can see whether they are increasing or decreasing but how much of a difference is that in real terms? If you understand what I mean by that!

Is it that close that it virtually qualifies as a MMW - and where do you get that figure from? Sorry if I'm having a blond moment lol, but that calculation is a part that I am not fully clear about. :)

It's not but you have to have a benchmark!

post-4523-1232191536_thumb.png

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It's not but you have to have a benchmark!

post-4523-1232191536_thumb.png

Tamara- If you refer to my even larger teapot thread Have a look at 5 M/S has done & 200 MB.........

S

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Guest North Sea Snow Convection
It's not but you have to have a benchmark!

post-4523-1232191536_thumb.png

Tbh - that looks good enough to me!

Tamara- If you refer to my even larger teapot thread Have a look at 5 M/S has done & 200 MB.........

S

ok - tks Steve

Edit - yes I see now. To get the best chance at a stable high latitiude block in a favourable position then we need to see that margin erased.

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Looking at the stratosphere temp charts this morning and at the 10hpa level it looks as though the rebound or cooling back of temps have stalled and are starting to rise once again.

If all of this verifies we could see some serious northern blocking throughout February and March and the implications that could well bring for the UK.

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Guest North Sea Snow Convection

NCEP updates

gfs_t10_nh_f240.gif

gfs_t30_nh_f240.gif

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NCEP updates

Thanks for putting them up Tamara. The 30 hPa warming looks better there.

I'm sorry I couldn't explain further what I meant earlier, I was on my way out. Nothing like a walk along the seafront to blow any cobwebs away!

Here are the latest pressure charts as well. Still slowly getting there but I can't tell whether the 10 hPa chart has a net easterly. Too close to call.

post-4523-1232207720.gif

post-4523-1232207746.gif

Regarding the 5.88m/s I think it is all important. I know that there is some concern that we may not get a SSW the first time of asking this winter, but after getting so near, it would be very frustrating were it not to occur. Whereas now the whole of the stratospheric vortex strength is forecast to be much reduced, to have a net change in direction, would ideally be what we would like to occur. To use another analogy, it's rather like a spinning top. To slow the spinning top down until it almost stops and then let it speed up again requires far less effort than stopping it, spinning it in the opposite direction, stopping it again and spinning it back in the original direction until it is back up to full speed. And that is what I would like to see occur, because later on, it could be the difference in February, between a mid latitude block and a high latitude block. I have to admit that -5ºC 850's don't float my boat. I'm greedy and want nothing less than -10ºC 850's. So lets hope this trend continues. Then it will be very much game on further down the line.

c

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Guest North Sea Snow Convection
Thanks for putting them up Tamara. The 30 hPa warming looks better there.

I'm sorry I couldn't explain further what I meant earlier, I was on my way out. Nothing like a walk along the seafront to blow any cobwebs away!

Here are the latest pressure charts as well. Still slowly getting there but I can't tell whether the 10 hPa chart has a net easterly. Too close to call.

Regarding the 5.88m/s I think it is all important. I know that there is some concern that we may not get a SSW the first time of asking this winter, but after getting so near, it would be very frustrating were it not to occur. Whereas now the whole of the stratospheric vortex strength is forecast to be much reduced, to have a net change in direction, would ideally be what we would like to occur. To use another analogy, it's rather like a spinning top. To slow the spinning top down until it almost stops and then let it speed up again requires far less effort than stopping it, spinning it in the opposite direction, stopping it again and spinning it back in the original direction until it is back up to full speed. And that is what I would like to see occur, because later on, it could be the difference in February, between a mid latitude block and a high latitude block. I have to admit that -5ºC 850's don't float my boat. I'm greedy and want nothing less than -10ºC 850's. So lets hope this trend continues. Then it will be very much game on further down the line.

c

Agree entirely :)

Lets hope it can go that extra half yard or so. I would like to see some reverse zonality and a decent blizzard or three as well :)

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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.

post-4523-1232266948_thumb.png

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

post-4523-1232266682_thumb.png

post-4523-1232266778_thumb.png

post-4523-1232266894_thumb.png

c

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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.

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