1227 replies to this topic

[Weather Ship]

Are we creeping in to a stronger vortex Chiono?

Edited by weather ship, 29 October 2011 - 14:28 .

[chionomaniac]

No changes seen in stratospheric conditions the last few days. Ozone forecasts are unremarkable leading to gradual cooling and a slow increase in the polar vortex strength. The only thing of note is a possibility that any Scandi Ridge will drop southwards at around the 10 days timeframe. If this occurs then I suspect that the jet will ride above. We have not seen that poorly angulated jet stream pattern for a while.

[SNOWPLOUGH]

Is the stratoshere not warming very slightly at the 30hpa level? (Still just below average though)

http://ds.data.jma.g...e/pole30_n.html





Dan

[summer blizzard]

Indeed we are seeing a warming of the stratosphere. We will need to keep it going for a few days although with the interquartile range still very close at this time of year it could indicate the potential for something good into December, we saw a similar event last year.

http://acdb-ext.gsfc..._2011_merra.pdf

This page is more detailed.

[phil n.warks.]

summer blizzard, on 31 October 2011 - 19:20 , said:

Indeed we are seeing a warming of the stratosphere. We will need to keep it going for a few days although with the interquartile range still very close at this time of year it could indicate the potential for something good into December, we saw a similar event last year.

http://acdb-ext.gsfc..._2011_merra.pdf

This page is more detailed.

I can only see one day of a slight upward curve on these graphs though.

We look about average at 30Hpa at present.

We need many more days before we can declare an upward trend.

[chionomaniac]

I tend to look at the average temperature between 60-90ºN. Cold pools can circle the pole at this time and so minor fluctuations at 90ºN can be picked up but the overall trend is still well below average.

http://acdb-ext.gsfc..._2011_merra.pdf

[phil n.warks.]

chionomaniac, on 31 October 2011 - 20:12 , said:

I tend to look at the average temperature between 60-90ºN. Cold pools can circle the pole at this time and so minor fluctuations at 90ºN can be picked up but the overall trend is still well below average.

http://acdb-ext.gsfc..._2011_merra.pdf

Thanks Chiono.

[cooling climate]

Ozone in the Arctic is looking better the past couple of days
plus there is an asian mountain torque event ongoing and a
uptick in 30 hpa stratosphere temperatures at the north pole.
Things are looking up.

[chionomaniac]

cooling climate, on 31 October 2011 - 20:22 , said:

Ozone in the Arctic is looking better the past couple of days
plus there is an asian mountain torque event ongoing and a
uptick in 30 hpa stratosphere temperatures at the north pole.
Things are looking up.

I wouldn't say ozone levels are high but the forecast is certainly looking better. Now is the time to assess the BDC level.

Yesterday's ozone



T+120



No signs in the forecasts yet that the Asian MT is creating a wave breaking event in the stratosphere but I agree good to see nonetheless.

[summer blizzard]

No luck on the stratosphere front, the warming was small.

[karyo]

summer blizzard, on 02 November 2011 - 19:17 , said:

No luck on the stratosphere front, the warming was small.

Yes, the cooling has resumed! However, at the moment we are not much below average.

http://acdb-ext.gsfc..._2011_merra.pdf

Karyo

[chionomaniac]

karyo, on 02 November 2011 - 21:55 , said:

Yes, the cooling has resumed! However, at the moment we are not much below average.

http://acdb-ext.gsfc..._2011_merra.pdf

Karyo

And still nothing on the horizon.

[Mark Bayley]

Quick look at this mornings update, nothing much to add really other than a continuation of the cooling at both the 10hpa and 30hpa level. This to me would suggest milder rather colder weather for the foreseeable future. Comparing this years and last stratospheric temperatures, there doesn't seem much difference so far, with last years temperatures remaining below the 30 year mean for most of the winter (we know what happened in December). Of course there are numerous other factors to consider, which i won't pretend to understand, and this years set up, is of course different to last year.



Saying that there is an indication from the GFS ensembles that we may see the AO and NAO trend negative as we progress through second half of November, it adds some support to a few peoples thoughts of a colder period of weather later on in the month.
http://www.cpc.ncep....ndex_ensm.shtml
http://www.cpc.ncep....ndex_ensm.shtml

Edited by Mark Bayley, 04 November 2011 - 12:05 .

[cooling climate]

There was a decent warming at the 30 hpa level at the end of last October
and into the first few days of November at 90 degrees north, although the
graphs that you have shown do not show it that well.

Edited by cooling climate, 04 November 2011 - 15:44 .

[karyo]

cooling climate, on 04 November 2011 - 15:43 , said:

There was a decent warming at the 30 hpa level at the end of last October
and into the first few days of November at 90 degrees north, although the
graphs that you have shown do not show it that well.

That's true but unfortunately no warming on the horizon currently!
An unsettled and mild Nov and Dec look more than likely now and the CFS shows this also.

Karyo

[chionomaniac]

Time for an update.

Firstly, an update on the Asian Mountain Torque event. There is a sustained mountain torque event which disrupts Rossby waves as they travel around the earth. The whole pattern and number of Rossby waves can change and be shifted.

One of the other affects is deflection of the wave into the stratosphere which can enter the polar vortex bringing in warmer air to the core as it does so. There is nothing so far to suggest that this MT is to create such an effect and I would have expected to see something of it in the forecasts were it to do so.

However, there is better news on the ECM forecasts at the troposphere/ stratosphere interface. so far this winter the stratospheric vortex has been positioned very much over towards the eastern Siberian segment and that looks set to continue. This has an effect on the positioning of the strongest tropospheric vortex which again has been towards the Pacific end. This has left an opportunity for a height rise in the Atlantic sector and for the first time this has been picked up at the 100hPA level with the ECM forecasts.

Here is the T+192 ECM forecast - very much an open door for Greenland height rises.



Will the GFS follow suit or will we be left looking at a block more SEasterly placed over the UK?

c

[johnholmes]

chionomaniac, on 07 November 2011 - 09:31 , said:

Time for an update.

Firstly, an update on the Asian Mountain Torque event. There is a sustained mountain torque event which disrupts Rossby waves as they travel around the earth. The whole pattern and number of Rossby waves can change and be shifted.

One of the other affects is deflection of the wave into the stratosphere which can enter the polar vortex bringing in warmer air to the core as it does so. There is nothing so far to suggest that this MT is to create such an effect and I would have expected to see something of it in the forecasts were it to do so.

However, there is better news on the ECM forecasts at the troposphere/ stratosphere interface. so far this winter the stratospheric vortex has been positioned very much over towards the eastern Siberian segment and that looks set to continue. This has an effect on the positioning of the strongest tropospheric vortex which again has been towards the Pacific end. This has left an opportunity for a height rise in the Atlantic sector and for the first time this has been picked up at the 100hPA level with the ECM forecasts.

Here is the T+192 ECM forecast - very much an open door for Greenland height rises.

ecmwf100f192.gif

Will the GFS follow suit or will we be left looking at a block more SEasterly placed over the UK?

c

I do think, to use the over used expression, building blocks, that more and more are slowly starting to drop into their needed position, they are not there yet as you rightly point out but I would be surprised if there is not a large change in the major wavelength pattern around the northern hemisphere before the end of the month.

[cooling climate]

I see that there is a forcast warming at 30 hpa 90 degrees
north on the ECM site. This could be worth watching.
For some reason I am not able to copy images at the moment
otherwise I would post it in here.

[chionomaniac]

cooling climate, on 07 November 2011 - 18:59 , said:

I see that there is a forcast warming at 30 hpa 90 degrees
north on the ECM site. This could be worth watching.
For some reason I am not able to copy images at the moment
otherwise I would post it in here.

Keeping an eye on that for a day or two cc as the NH charts show that it is only a minor warming as the vortex slightly retreats to the Eastern Siberian sector. Ozone levels slowly on the increase.

[Mark Bayley]

cooling climate, on 07 November 2011 - 18:59 , said:

I see that there is a forcast warming at 30 hpa 90 degrees
north on the ECM site. This could be worth watching.
For some reason I am not able to copy images at the moment
otherwise I would post it in here.

Here you go

Something worth watching over the coming days.


Edit: Should now be recent one

Edited by Mark Bayley, 07 November 2011 - 19:10 .