Stratosphere Temperature Watch 2011/2012

[karyo]

_{Yes, that's true and I think GP is expecting a major warming around mid January!}

_{I was hoping for something more significant now so that we don't have to wait till February to see the effects.}

_Karyo

[bluearmy]

To be fair, there has never been an appetite for 30hpa temp spike at 60N. So far, the predicted warming has been no lower than 10hpa as far as any big increase in temps are concerned. cpc data today shows the warming lower down in the strat to be around alsaska/western canada and the gefs seems to show this area as being most likely to see marked ridging in a couple of weeks time

To be fair, there has never been an appetite for 30hpa temp spike at 60N. So far, the predicted warming has been no lower than 10hpa as far as any big increase in temps are concerned. cpc data today shows the warming lower down in the strat to be around alsaska/western canada and the gefs seems to show this area as being most likely to see marked ridging in a couple of weeks time

[chionomaniac]

Best ozone forecast this winter

[sebastiaan1973]

Chio, is it a coincidence that the highest ozon levels are found near the Aleoeten (I'm not sure this the right word in English, I'm Dutch)? We often see high pressure in La Nina years in this area.

[phil nw.]

Best ozone forecast this winter

Which matches pretty close to the GFS Temp.profile at 30hPa at T240hrs.

That`s the area that seems destined for any blocking down the line with the PV still forecasted to be over the Arctic to the north of UK at T240.

At that stage if this GFS forecast verifies the best we could expect for anything colder is a flow more North of West at times,

A fairly flat zonal pattern across the Western Hemisphere--which fits in well with current daily modelling up to T240hrs.

It is apparent that the present forecasted warming is only slowing the Upper levels within this time period -here the ECM T240 zonal mean temp.

which backs up the GFS Strato images above.

Based on this imo we should expect no change yet in the Trophospheric modelling from the effects of any current warmings.

Edited December 24, 2011 by phil n.warks.

[SxK]

_{Yes, that's true and I think GP is expecting a major warming around mid January!}

_{I was hoping for something more significant now so that we don't have to wait till February to see the effects.}

_Karyo

Yes for those looking for snow this is perhaps the biggest hurdle. If as Chio puts it we need a few waves to knock over our sandcastle then by the time we get favourable strat conditions that impact our weather pattern we could be nearing March. I am not particularly enthusiastic about a canadian HP nor with the projected warming, time will tell but those expecting to see dramatic changes in the model output are sadly going to be disappointed. Without a SSW a lot of patience going to be required

Edited December 24, 2011 by samkeep

[sebastiaan1973]

First, everybody merry Christmas.

Update of this morning. More or less in my opinion in the same line of yesterday.

-at 10hpa a increase of temperature above normal, declining after some time to normal

-at 30hpa near normal

So temperature rising takes places especially in the higher levels of the stratopshere

The zonal wind drops at 1hpa and continues at the same level or even rises at 10hpa and 30hpa

60oN Zonal Mean Zonal Wind is back to normal (since the end of october it was above!)

GFS FI is still predicting another 'heatwave' at 10hpa. So we have to wait and wait and wait....

Edited December 25, 2011 by sebastiaan1973

[bluearmy]

Looks like a lot of uncertainty as to which way this will go, but I think some members were calling the outcome of a race where the starter had not even fired the pistol.

Certainly the US guys that I follow are not confident about proposed warming, though they appear to place less emphasis on the Strat factor than we are seeing here right now.

Maybe so Ian - however, the vortex certainly appears to be under pressure in the current fi modelling and having viewed the us forum, ed seems to be as 'on the ball' re the strat as most of them.

[phil nw.]

Just a quick one from me

All the Data i have viewed shows no warming forecasted within 10 days at the lower levels ,where it matters for any effect on the Trophosphere.

At some point further out something may show up but imo too much is being made of current FI modelling where there is no tangible sign of Arctic blocking

Edited December 25, 2011 by phil n.warks.

[bluearmy]

Just a quick one from me

All the Data i have viewed shows no warming forecasted within 10 days at the lower levels ,where it matters for any effect on the Trophosphere.

At some point further out something may show up but imo too much is being made of current FI modelling where there is no tangible sign of Arctic blocking

Wrong thread to discuss the models Phil but there have been plenty of gefs members past day or so that do show arctic blocking and several have even shown a split vortex. I agree that there has been no warming of note shown below 20 hpa. Something is causing the models to play around with the vortex in fi land, having not done so for many weeks.

[phil nw.]

Wrong thread to discuss the models Phil but there have been plenty of gefs members past day or so that do show arctic blocking and several have even shown a split vortex. I agree that there has been no warming of note shown below 20 hpa. Something is causing the models to play around with the vortex in fi land, having not done so for many weeks.

Mmm Nothing to suggest any downwelling within T240 to lower levels though as i said.

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf30f240.gif

I will be interested to see if we get wavebreaking into the heart of the vortex from the Trophosphere which is an upwelling--the effect by inference would be a quicker route to blocking.

Mind you i would have thought this will show up on the Strato forecasts on the100hPa output when it`s picked up-nothing yet-within 10 days

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf100f240.gif

--maybe soon if the trophospheric output is toying with this like you suggest as GFS goes to 15 days on the 500hPa levels.

[chionomaniac]

Looks like a lot of uncertainty as to which way this will go, but I think some members were calling the outcome of a race where the starter had not even fired the pistol.

Certainly the US guys that I follow are not confident about proposed warming, though they appear to place less emphasis on the Strat factor than we are seeing here right now.

There is no doubt about the warming that is occurring in the upper levels of the the strat. What appears to be over estimated by the ECM is the effect on the vortex and propagation downwards. Mark my words though Ian, it is far too early to be writing off the effects of the stratosphere for the rest of the winter.

A warming that is forecast to completely overwhelm the vortex at 1 hPa at day 10 surely has to have a bigger effect than forecast yet?

[bluearmy]

There is no doubt about the warming that is occurring in the upper levels of the the strat. What appears to be over estimated by the ECM is the effect on the vortex and propagation downwards. Mark my words though Ian, it is far too early to be writing off the effects of the stratosphere for the rest of the winter.

A warming that is forecast to completely overwhelm the vortex at 1 hPa at day 10 surely has to have a bigger effect than forecast yet?

Ed, you think a forcast split vortex ECM op T240 isn't big enough considering how strong the p/v is ???? I'm sure it's the usual ecm op progressive bias but aren't you surprised to see the highest resolution model do this??

[chionomaniac]

Ed, you think a forcast split vortex ECM op T240 isn't big enough considering how strong the p/v is ???? I'm sure it's the usual ecm op progressive bias but aren't you surprised to see the highest resolution model do this??

I don't know how relevant the upper strat warming is in this case, but I did point out earlier in the month that the zonal mean wind anomalies were dropping anyway and forecast that even without the warming there will be some reduction in the polar vortex strength. I wonder is the ECM overplaying the Arctic high though.

Still, more interest for the New Year

[nick sussex]

I wonder if the PV is more likely to respond to a warming because of how strong its recently been.

Using an analogy think of a reservoir filled to capacity, and our forecast warming is a little explosive, this blows a hole in the dam and the result is a bigger outflow of water because of the weight of the full reservoir.

A weaker PV reservoir half full, the result of the explosive is a weaker rush of water out. Perhaps theres a critical point in the PV where its no longer able to sustain itself so the higher the climb the bigger the fall.

And because its reached that bloated point the smallest warming effects it. I'm sure theres a better analogy I could use but hopefully it makes some sense!

Edited December 26, 2011 by nick sussex

[phil nw.]

Todays Zonal wind forecast shows a reversal at T240 at the lowest level.

which reflects the 500hPa weakness in the centre of the Vortex on the 00z ECM at T240.

With no forecasted warming getting down to these levels from above within this timeframe,could we be looking at a possible attempt at an upwelling event created by wavebreaking from below ie the Trophosphere?I did mull over this with B.A last night.

Edited December 26, 2011 by phil n.warks.

[SMU]

we need a more negativity in the zonal wind anomaly to really see some change in the Pattern, it is great when we get a strong easterly anomaly & that really promotes blocking tendencies, as it stands the zonal mean going slightly below is neutral for me so it isnt suge a huge player- although its certainly better than a strong positve westerly one..

S

[chionomaniac]

I wonder if the PV is more likely to respond to a warming because of how strong its recently been.

Using an analogy think of a reservoir filled to capacity, and our forecast warming is a little explosive, this blows a hole in the dam and the result is a bigger outflow of water because of the weight of the full reservoir.

A weaker PV reservoir half full, the result of the explosive is a weaker rush of water out. Perhaps theres a critical point in the PV where its no longer able to sustain itself so the higher the climb the bigger the fall.

And because its reached that bloated point the smallest warming effects it. I'm sure theres a better analogy I could use but hopefully it makes some sense!

I used to think that, but don't now. One just needs to compare to the polar vortex set up over Antartica and one can see that the Arctic could cool and increase in strength a lot more than it does. It highlights the importance of land mass interaction as well.

[cooling climate]

Todays Zonal wind forecast shows a reversal at T240 at the lowest level.

which reflects the 500hPa weakness in the centre of the Vortex on the 00z ECM at T240.

With no forecasted warming getting down to these levels from above within this timeframe,could we be looking at a possible attempt at an upwelling event created by wavebreaking from below ie the Trophosphere?I did mull over this with B.A last night.

As far as I understand things you can have wave breaking at different levels of the

Stratosphere not just bottom down or upwelling from the bottom up.

On the Stratosphere temperature charts of the GFS the warming at 100 hpa

looks far greater than at 30 hpa at t240.

[phil nw.]

As far as I understand things you can have wave breaking at different levels of the

Stratosphere not just bottom down or upwelling from the bottom up.

On the Stratosphere temperature charts of the GFS the warming at 100 hpa

looks far greater than at 30 hpa at t240.

Yes i was speculating re.the upwelling as this is all new to me C.C.--i was just going by the data.As Steve M said above ,although only minor, Zonal wind reversal is better that the positive state than we have had-- so a small step in the right direction.

Obviously the modelling of the 500hPa output only shows a small lessening in the vortex strenth at T240

--no blocking there yet.

Edited December 26, 2011 by phil n.warks.

[Cecil Hogmanay Melchett]

Worryingly i suspect the green shoots of optimism are slowly diminishing in this thread to!

If we are going to see a MMW or SSW i think we ought to hope they happen soon as i fear an event late in Jan with the time lag assosiated will come to late to save what is fast turning into a very very poor winter..

The latest meto outlook has no mention of anything resemembling high lat blocking all the way out to the last week of Jan.

That would leave Feb as the last and only hope.

[phil nw.]

Worryingly i suspect the green shoots of optimism are slowly diminishing in this thread to!

If we are going to see a MMW or SSW i think we ought to hope they happen soon as i fear an event late in Jan with the time lag assosiated will come to late to save what is fast turning into a very very poor winter..

The latest meto outlook has no mention of anything resemembling high lat blocking all the way out to the last week of Jan.

That would leave Feb as the last and only hope.

This thread is really for learning and monitoring wrt the Stratosphere H.D.

Although i am a cold lover we try to keep objective and just see through the season how much the behaviour of the Strato. has on the Trophospheric modelling.

If we manage to see some cold then great but thats not the real purpose of posting in here.

[Duane S.]

Worryingly i suspect the green shoots of optimism are slowly diminishing in this thread to!

If we are going to see a MMW or SSW i think we ought to hope they happen soon as i fear an event late in Jan with the time lag assosiated will come to late to save what is fast turning into a very very poor winter..

The latest meto outlook has no mention of anything resemembling high lat blocking all the way out to the last week of Jan.

That would leave Feb as the last and only hope.

Not really sure where all this hope for an early SSW came from? As from as i am aware SSW / MMWs (same thing) are very unusual in December anyways, what we are looking at here are warmings hopefully leading to an SSW later on in January

[weatherjunkie]

I suspect the low level wind reversal on the ECMWF is a function of the MJO pushing into phase 6 and given the composites I've seen the high latitude HP is allowed to build and amplify. Certainly phase 6 suggests -NAO given the W Pac tropical forcing.

Edited December 26, 2011 by weatherjunkie

[sebastiaan1973]

From day 6-10 a reversal at the higher levels. Not at the lower levels. I think it's a start and we need another 'heat' wave.

Edited December 27, 2011 by sebastiaan1973