Stratosphere Temperature Watch

[Guest North Sea Snow Convection]

Clear indications in the tropospheric models now that the full impacts of the MMW are on there way in the not too distant future. It puts the expected timeframe for surface response in line with previous predictions and looks like setting up for the second half of February very much along the lines that GP has outlined in his GWO updates.

Meanwhile stratospheric 'reverse zonality' goes on and on. Trying to find another superlative to 'amazing'!

Great animation there - clearly shows the original mountain torque event over Asia occuring during January.

Edited February 5, 2009 by North Sea Snow Convection

[Mondy]

Some of you may like to read this

[phil nw.]

Just caught up on this thread and again wish thank all the contributers,particularly C and NSSC.

A really interesting subject and the informative posts from you guys help me understand a little more.

Great stuff--keep it up.

[Guest North Sea Snow Convection]

Some of you may like to read this

Thanks for that link. Very interesting, and a train of thought I would agree with.

I think that would be very useful to introduce into the climate threads. Some nice new meat to throw into the debate defintely

Just caught up on this thread and again wish thank all the contributers,particularly C and NSSC.

A really interesting subject and the informative posts from you guys help me understand a little more.

Great stuff--keep it up.

Hi Phil - and thanks

We are now at a time when parallel checks can be made in terms of the magnitude of the MMW and the fact that it is almost certainly coming into the model ranges output. The good thing is that as yet there is no switch from polar easterly back to polar westerly within the 10 day forecast range - and that is on top of the considerable time already elapsed since the central warming date. (The date that zonal winds were reversed at both the 10hpa and 30hpa in the stratosphere)

The surface effects of this event could be felt for a considerable period of time, in view of the fact that there is no event on records that can have comparison. So as C says, we are in unchartered waters.

Edited February 5, 2009 by North Sea Snow Convection

[Mondy]

Thanks for that link. Very interesting, and a train of thought I would agree with.

I think that would be very useful to introduce into the climate threads. Some nice new meat to throw into the debate defintely :o

I shall allow you to add the link there. I take no part in that area now. My own choice :o

[7andY]

A quick question, if I may.

We're talking here of a SW event that has yet to impact on the Troposphere, I take it?

If that's the case, and there is as yet no impact, and the forecast models do not utilise Stratospheric data, why are people saying that they can see these impacts out in FI. If it's not yet appearing as data in the models, then surely no model output can be ascribed to it.

And once the effects filter down (pun intended ) into the models, surely the effects will appear in a timeframe closer than FI, and FI will change markedly in response.

Confused :blush:

7&Y

PS I like to think that FI really means Forecast Inconclusive!!

[leroys41]

what the pros think of the latest cpc charts dont look that good you agree

[chionomaniac]

Just caught up on this thread and again wish thank all the contributers,particularly C and NSSC.

A really interesting subject and the informative posts from you guys help me understand a little more.

Great stuff--keep it up.

Thanks Phil

A quick question, if I may.

We're talking here of a SW event that has yet to impact on the Troposphere, I take it?

If that's the case, and there is as yet no impact, and the forecast models do not utilise Stratospheric data, why are people saying that they can see these impacts out in FI. If it's not yet appearing as data in the models, then surely no model output can be ascribed to it.

And once the effects filter down (pun intended ) into the models, surely the effects will appear in a timeframe closer than FI, and FI will change markedly in response.

Confused

7&Y

PS I like to think that FI really means Forecast Inconclusive!!

Hi 7andY,

I do believe that the models have some stratospheric input but I don't know how much. The following link from the met office suggests that this is a consideration when their own models are run. I am sure the GFS and ECM will also have data fed in. Even if they don't there will be enough preliminary change at the top of the troposphere which eventually filters down that the models will put into the forecasts.

http://www.metoffice.gov.uk/science/creati...ratosphere.html

Elsewhere this evening there are slight changes from a couple of days ago at the 100 hPa level. Remember this si really the boundary level between the stratosphere and the troposphere known as the tropopause. I have now worked out that even though the stratosphere forecasts are pretty reliable upto T+240 the closer down to the troposphere one gets the more variation there is in the forecasts.

A couple of days ago the split 100 hPa level vortex was programmed to rejoin over the North Pacific which looked like it left the door open for possible Scandinavian height rises as shown here.

Now for the same day (13th Feb) this looks less likely on today's forecast. In fact one would say that the UK would be the prime spot for height rises. An island segment of vortex has been left west of Greenland and also an extension over Italy.

If the lower troposphere follows the same pattern ( may be with a slight delay) then perhaps WAA may occur over western Greenland which could ultimately encourage blocking and a Greenland high could now occur. Looking at the forecast for 2 days later and definitely a possibility.

Blocking to build from the UK/ east Atlantic and extend NWestwards? Please note I am just looking for trends and possibilities at this time but I think this would be more in line with GP's and Tamara's thoughts! We shall see.

Looking at the ECM forecast for around the same time and a similar pattern is evolving.

Certainly high latitude blocking is on the cards - working out exactly where it is going to occur is another matter altogether!

c

[tundra]

With one part of the major warming occurring over Greenland then it has always been the main candidate for the block to form there with low pressure over Europe. The high will then ridge towards Scandinavia with more of a continental Arctic airflow over northwest Europe and the UK.

By far the coldest weather of the winter will be between mid February and mid March. Although cold and wintry we haven't seen any really cold weather yet.

[johnholmes]

re this

I do believe that the models have some stratospheric input but I don't know how much. The following link from the met office suggests that this is a consideration when their own models are run. I am sure the GFS and ECM will also have data fed in. Even if they don't there will be enough preliminary change at the top of the troposphere which eventually filters down that the models will put into the forecasts

GFS from NOAA, I posted some time ago, has no input whatever other than the routine input of data as it is is at 00, 06, 12 and 18z.

http://www.metoffice.gov.uk/science/creati...ratosphere.html

private discussion with UK Met confirms that they have no input either. The comments above are about the model dealing with non synoptic outputs.

[chionomaniac]

re this

I do believe that the models have some stratospheric input but I don't know how much. The following link from the met office suggests that this is a consideration when their own models are run. I am sure the GFS and ECM will also have data fed in. Even if they don't there will be enough preliminary change at the top of the troposphere which eventually filters down that the models will put into the forecasts

GFS from NOAA, I posted some time ago, has no input whatever other than the routine input of data as it is is at 00, 06, 12 and 18z.

http://www.metoffice.gov.uk/science/creati...ratosphere.html

private discussion with UK Met confirms that they have no input either. The comments above are about the model dealing with non synoptic outputs.

Thanks John. If we have had to wait for the MMW effects to filter down to the upper troposphere before this is included in the modeling then I suspect this will be occurring around now. Which figures, but I would say the ECM and their ensembles seem to be a day ahead of the GFS.

c

[chionomaniac]

Guess what? No, you're wrong! We still have polar stratospheric easterlies forecast.

I am also keeping an eye on the 30 hPa temps. These also seem reluctant to drop back to average.

c

[Guest North Sea Snow Convection]

I think we are seeing the win all/lose all scenarios being played out by the models in terms of where the height rises manifest, courtesy of the MMW. From our own Uk point of view ECM says 'yes' but GFS now says 'no' and is flying the american flag with height rises over the Canadian side of the arctic and a very poor result for us.

We have never guaranteed a cold outcome with this MMW, but surely hoping the ECM is on the button.

Edited February 6, 2009 by North Sea Snow Convection

[Weather-history]

Northerly blocking is never a guarantee of cold weather for the UK.

Pressure was above normal across the polar regions during March 1957, in fact pressure was actually above average for south Greenland during that month but it was the mildest March on record for the UK.

Edited February 6, 2009 by Mr_Data

[johnholmes]

a very pertinent post there Mr D

[Gray-Wolf]

And whose to say where any 'promoted blocking' would occur? We all know how different one side of a H.P. can be to the other so whose to say which side we'll find ourselves on? Do any of the guys 'in the know' have records of MMW bringing us Bartlett type weather?

Another question I have (for those guys) is when was the earliest FW recorded? The longer this event stretches out the closer it must be becoming to be the final warming of the year surely?

[Guest North Sea Snow Convection]

And one that has been maintained throughout this thread. Despite natural favouritism, any reasons for 'homeland optimism' of placement of blocking has been intended based on facts, as they have been evolving, and not wishful thinking as is often suggested.

[LadyPakal]

Article about SSW here: http://icecap.us/ - in the middle column. May be of interest...

[chionomaniac]

And whose to say where any 'promoted blocking' would occur? We all know how different one side of a H.P. can be to the other so whose to say which side we'll find ourselves on? Do any of the guys 'in the know' have records of MMW bringing us Bartlett type weather?

Another question I have (for those guys) is when was the earliest FW recorded? The longer this event stretches out the closer it must be becoming to be the final warming of the year surely?

Hi GW

The question about favourable blocking and previous instances of unfavourable blocking would take a fair old time to research. Because of the complex nature and difference of each MMW there becomes a good list of factors that contribute where and when and if ultimately blocking will occur. These include type of MMW, propagation ability, strength, lower stratospheric vortex position, possible split and reforming position and duration of the event. After that we can then start to look at all the major tropospheric influences. As you can begin to imagine that looking at all of these and then tracking the corresponding date for 30 days previous and post the central date and comparing to available NH historical troposphere charts could take a little time!

Having said that we suffered a poor propagator MMW at the end of Dec 2001 and Jan 2002 was miserable!

Regarding MMW's leading to Final Warmings (FWs). No FW has occurred in January before. There are two examples that I can find that occurred in February. One from an MMW that occurred in 22nd Feb 1979 the other 21st Feb 1989.

If this MMW produces a FW then this would be the earliest by a fair way.

c

[Gray-Wolf]

Before too many horses get put before too many Carts can some-one wise me up to what propagates a stratospheric warming in the first place?

Is it always compression of the stratosphere by the troposphere or is there any credence in the Strat being squeezed from outside the atmosphere by extra-terrestrial means (solar flare or other sources)?

Some of the things I've read today have me confused.

If we are always looking at a terrestrial cause then ,it would seem to me, that we always are already in a position, prior to the event, for a 'predictable outcome' downstream as the rosby wave impacts the weather patterns downstream. If we can have our stratosphere squished by outside influences then the 'disturbed' weather patterns leading to an amplified rosby wave do not ,necessarily, exist in the weather system and it's impact ,further downstream, will not occur.

If we have two broad causal factors, terrestrial and off world, then we may have an answer as to why some SSW's promote predicable cooling while others don't.

Do shift this question if you feel the need but do try and answer it !

Ta.

Ian.

Edited February 6, 2009 by Gray-Wolf

[chionomaniac]

GW,

It's late, just in, but here are two papers to help you.

http://center.stelab.nagoya-u.ac.jp/cawses...mazaki_koji.pdf

http://www.columbia.edu/~lmp/paps/charlton...-JCLIM-2007.pdf

c

[Erl Happ]

Before too many horses get put before too many Carts can some-one wise me up to what propagates a stratospheric warming in the first place?

Delta X Ray Here is a Clydesdale for a Cart.

The Sudden Stratospheric Warming has its greatest effect at the highest elevation. This suggests a top down causation.

The onset of the SSW in the Arctic was five days after the appearance of a new sunspot group that generated X ray activity.

According to my calculations the transit time from the Sun to the Earth at the current solar wind speed of about 350km per second is about 5 days. That was the lag period before the onset of the warming. I suggest that this event is related to the magnetosphere and energising effects of the solar wind on the Arctic atmosphere. A warm temperature anomaly is evident is all the way down as far as 300hPa at 60-90°N. See current GDAS -CPC Zonal anomaly 60-90N. That warming also appears at 25°N to 65°N as you can also see in the diagrams at: http://www.cpc.ncep.noaa.gov/products/stra...ere/strat-trop/

Here is the kicker: Concurrent with the warming in the Arctic stratosphere/troposphere we have a marked cooling in the stratosphere at 25°N to 25°S. See:http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/index.shtml

This suggests a compression (or piling up) of the atmosphere between 20°N latitude and Antarctica commensurate with marked expansion of the atmospheric column(with heating) in the northern part of the northern hemisphere. Accordingly there is a concomitant reduction in the energizing effect of ionizing radiation on the stratosphere/upper troposphere between 20°N and Antarctica. The resultant instantaneous cooling can be detected as far down as 150Hpa at 10°N to 10°S and in a downward deflection of the stratosphere temperature curves in the southern hemisphere.

We have to bear in mind is that the Earths atmosphere is ever changing. Currently, the tropical sea and the stratosphere is cool and dry (paucity of convection in the tropics). In this circumstance ozone levels in the stratosphere recover so it becomes much more reactive to small changes in ionising radiation. This effect is exaggerated in the winter hemisphere. So, the absolute levels of the solar parameters are a poor guide as to what to expect. The stage is set by the atmosphere itself and the temperature of tropical waters.

The warming of the stratosphere and upper troposphere in the current instance extended into the mid latitudes of the northern hemisphere that carry the high pressure cells. That warming has the capacity to change sea surface temperature at these latitudes due to loss of high altitude cloud, particularly in those mid ocean locations that have high ozone concentrations in the upper troposphere. The warmer waters will gradually be driven towards the equator by the North East Trade winds.

Perhaps the loss of central pressure due to upper troposphere warming in mid latitudes is associated with heightened pressure in the Arctic vortex and the onset of very cold weather at high latitudes that seems to follow the sudden stratospheric warming.

Delta X Ray and Nimbostratus: Thanks for the reference to my blog. It helps keep me motivated. Erl

[AtlanticFlamethrower]

The onset of the SSW in the Arctic was five days after the appearance of a new sunspot group that generated X ray activity.

What sunspot group? Over the past year have been precious few sunspots, there certainly wasn't a group of them in January. Currently the sun is totally spotless.

[LadyPakal]

There were a couple of small shortlived SC23's in the last few weeks. A small SC24 cluster some time before that...

Keep an eye on this thread:

http://www.netweather.tv/forum/index.php?s...4&start=714

Edited February 7, 2009 by LadyPakal

[chionomaniac]

I am trying to keep this thread to the monitoring aspects of the stratosphere this winter. I find the research aspects fascinating but I notice that GW has opened up a thread and would be grateful if any research aspects of MMWs and the stratosphere are posted there.

http://www.netweather.tv/forum/index.php?s...p;#entry1472929

Many thanks.

c