Stratosphere temperature watch - 2016/17

[phil nw.]

11 minutes ago, Interitus said:

Forecast from 2nd December, well out of date. Go to sister site http://acdb-ext.gsfc.nasa.gov/Data_services/met/ann_data.html forecast from today.

So for comparison 50mb increasing as per above - http://acdb-ext.gsfc.nasa.gov/Data_services/met/metdata/annual/merra2/u60n_50_2016_merra2.pdf

Thanks for that Interitus the site link i had didn't show the date or if it did it wasn't clear to me.Yes the up to date forecast is different somewhat ,i shall use that one in future.

[Interitus]

The graphs are timestamped, lower right corner 

 

[Weather-history]

On 06/12/2016 at 18:22, feb1991blizzard said:

This is a split!!!!

Yet the tropospheric pattern, at least on our side of the northern hemisphere was not that impressive. Not compared to the eye popping synoptics of December 2010 and March 2013 or indeed mid December 2009-mid January 2010.

[feb1991blizzard]

11 minutes ago, Weather-history said:

Yet the tropospheric pattern, at least on our side of the northern hemisphere was not that impressive. Not compared to the eye popping synoptics of December 2010 and March 2013 or indeed mid December 2009-mid January 2010.

They were but only for a few days, in 2013 the pattern just kept repeating though.

[Nouska]

8 hours ago, Weather-history said:

Yet the tropospheric pattern, at least on our side of the northern hemisphere was not that impressive. Not compared to the eye popping synoptics of December 2010 and March 2013 or indeed mid December 2009-mid January 2010.

Much will depend on the positioning and whether it is tropospheric wave led or SSW downward propagation. Time delay plays a big part in looking at patterns at the surface.

Late November 2010 split.   tropospheric led

Mid January SSW 2013 split  

Mid December 2009                tropospheric led.

An edit to say that the '09 and '10 wave patterns are, according to recent research, very typical of solar minimum/early ascent stage of solar cycle. Tendency for strong ridging through Greenland - Kamchatka route, connecting Atlantic to Pacific ridge and thus cross polar flow.

Edited December 8, 2016 by Nouska

[bluearmy]

Not sure why the SSW musings have gained traction

currently there is evidence that both ec seasonal and glosea are both seeing the upper strat zonal wind increase back up to usual levels for mid dec onwards and yet they both predict high height anomalies to our north through jan and in the  case of ec, feb and march aswell.  so why the disconnect predicted between strat and trop. this isn't a situation where we see a disconnect occur and then look back to see the reasons why. this is a predicted disconnect. anyone got any thoughts?  we have seen strat/trop disconnects before.  has the fact that we should be E QBO and yet we are W QBO got anything to do with it ?? 

[Nouska]

24 minutes ago, bluearmy said:

Not sure why the SSW musings have gained traction

currently there is evidence that both ec seasonal and glosea are both seeing the upper strat zonal wind increase back up to usual levels for mid dec onwards and yet they both predict high height anomalies to our north through jan and in the  case of ec, feb and march aswell.  so why the disconnect predicted between strat and trop. this isn't a situation where we see a disconnect occur and then look back to see the reasons why. this is a predicted disconnect. anyone got any thoughts?  we have seen strat/trop disconnects before.  has the fact that we should be E QBO and yet we are W QBO got anything to do with it ?? 

I remember musing in the ENSO thread as to whether such a dramatic end to the winter vortex would leave a 'memory imprint' to see in the new winter season. This was also predicated on the QBO anomaly. I've no expertise in this field - just like to ponder some of my pattern knowledge, in another field, on to atmospheric behaviour. Probably mad, but there you go!

[phil nw.]

1 hour ago, Nouska said:

I remember musing in the ENSO thread as to whether such a dramatic end to the winter vortex would leave a 'memory imprint' to see in the new winter season. This was also predicated on the QBO anomaly. I've no expertise in this field - just like to ponder some of my pattern knowledge, in another field, on to atmospheric behaviour. Probably mad, but there you go!

Could be something in that Nouska.Add that to the Autumnal wave action on the vortex which has held back it's development by several weeks.

It leaves the lower levels perhaps more prone to further bottom up warmings if and when tropical convection get's organised with another bout of activity via the MJO.This maybe is what seasonal modeling is seeing in the coming weeks.

Like you though i am only musing/speculating.

Edited December 8, 2016 by phil nw.
corrected spelling-again

[Iceberg]

I've been keeping an eye on this warming on the gfs. It's been pretty consistent on both operational and p gfs versions. A coupled warming crossing the Atlantic and a clear displacement increasingly into Russian. Both getting stronger as we move into the last week of December. 

For me the disconnect is due to the highly fluid nature of the lower strat layer. 

[Daniel*]

Thoughts? 

[bluearmy]

47 minutes ago, Changing Skies said:

Thoughts? 

I had noticed this and am watching. Not sure how reliable GEFS are at that range. 

there is indeed an unhappy looking vortex predicted days 8/12 but it's unclear thereafter on the GEFS mean what will happen towards 10hpa. will be interesting to see the predicted zonal flow late on over the next few days on Berlin and see if the strengthening eases off as the stretching develops at that timescale. 

Edited December 8, 2016 by bluearmy

[Duane S.]

Will be interesting to the the next update or 2 to the QBO plot. I assume we are going to see a sharp drop off, down to around 15mb, to easterlies. The question will be how quickly they can descend from that height, with the current WQBO signature very much in place.

Also, the apparent disconnect between the upper and mid Strat is very intriguing. I'm not sure I can remember seeing this to this degree before. I'm sure at some point in the near future this will change but it can't be a bad thing whilst it lasts. I think!

[bluearmy]

Yesterday's Berlin charts show the renewed zonal flow struggling to make headway down through the strat. whilst it strengthens high up, if anything, it eases up between 20 and 50 hpa. Remaining slack below that above 50N

[Singularity]

Looking at the ECM data on the Berlin site, down to 70 or even 100 hPa, the Canadian vortex lobe looks to locate far enough south and west that there could conceivably be troughs digging well down into the Central U.S. with ridges thrown up ahead of them as the N. Atlantic sector sees amplification too.

Yet instead we see the lowest levels and the troposphere seeming very tilted eastward or even disconnected, allowing those deep troughs to edge into the Atlantic, the associated cold air then being the catalyst for deep cyclogenesis that turns what would be a chilly regime under a mid-lat block into an often mild and murky one on the periphery of a Euro ridge prior to it perhaps being squashed out completely in the 10-14 day range.

So I wonder - what are the chances that the vortex will actually be better aligned through the lowest levels, leading to the amplified outcome or at least encouraging it prior to the anticipated impact of tropical forcing by around a fortnight from now?

 

[JeffC]

Be gentle with me guys I'm about as far away from being an expert in the stratosphere as I am from being a millionaire!

I really like this site as it gives a reasonably real time picture of what's happening - I assume it's pieced together from the data collected around the world, but when you click on the Earth tab you get various criteria upon which to base your view and when you click between 70 & 250 HPa, it shows a marked difference in circulation  and a rather striking disconnect between the higher & lower strat.

https://earth.nullschool.net/#current/wind/isobaric/850hPa/overlay=temp/orthographic=-17.43,66.03,327/loc=-17.135,54.211

Just thought it might help some who like me struggle to visualise things off some of the charts

[Interitus]

7 hours ago, JeffC said:

Be gentle with me guys I'm about as far away from being an expert in the stratosphere as I am from being a millionaire!

I really like this site as it gives a reasonably real time picture of what's happening - I assume it's pieced together from the data collected around the world, but when you click on the Earth tab you get various criteria upon which to base your view and when you click between 70 & 250 HPa, it shows a marked difference in circulation  and a rather striking disconnect between the higher & lower strat.

https://earth.nullschool.net/#current/wind/isobaric/850hPa/overlay=temp/orthographic=-17.43,66.03,327/loc=-17.135,54.211

Just thought it might help some who like me struggle to visualise things off some of the charts

It would be better to compare the 70 and 10 hPa charts - the 250 hPa level is generally in the troposphere. Of course, the tropopause isn't at a fixed height or pressure level and can be defined traditionally according to lapse rates, or through potential vorticity - the dynamic tropopause, and locally in tropopause folds the stratosphere can reach down below the 500hPa/500mb level.

[JeffC]

7 hours ago, Interitus said:

It would be better to compare the 70 and 10 hPa charts - the 250 hPa level is generally in the troposphere. Of course, the tropopause isn't at a fixed height or pressure level and can be defined traditionally according to lapse rates, or through potential vorticity - the dynamic tropopause, and locally in tropopause folds the stratosphere can reach down below the 500hPa/500mb level.

Thanks, I even checked all the pressure / height figures and it looked to me that the 250 hPa was pretty much the lower level of the start, but as you say there will be varying heights at which that figure occurs. Either way I find it interesting as a help to decipher some of the more complex meteorological concepts.

[knocker]

8 hours ago, Interitus said:

It would be better to compare the 70 and 10 hPa charts - the 250 hPa level is generally in the troposphere. Of course, the tropopause isn't at a fixed height or pressure level and can be defined traditionally according to lapse rates, or through potential vorticity - the dynamic tropopause, and locally in tropopause folds the stratosphere can reach down below the 500hPa/500mb level.

I was looking at the Fort Smith 00z sounding  earlier (North West Territories, Canada) as it is in the zone of the Arctic trough and very cold air and it's a good example of unusual airmasses. (for us anyway). Much cold air in the lower layers and the Tropopause down at 358mb which could easily have been 440mb

[bluearmy]

wow - suddenly the Berlin zonal charts look much angrier towards the end as the zonal flow drifts further down than before. at the lower end of the strat 60N 100hpa the increase overall from 12 m/s to 18 m/s T0 to T240. For reference, this time last dec around 24 m/s. 

Wave activity dropping out towards the end of the run. 

[northwestsnow]

6 minutes ago, bluearmy said:

wow - suddenly the Berlin zonal charts look much angrier towards the end as the zonal flow drifts further down than before. at the lower end of the strat 60N 100hpa the increase overall from 12 m/s to 18 m/s T0 to T240. For reference, this time last dec around 24 m/s. 

Wave activity dropping out towards the end of the run. 

BAD.news..

[JeffC]

1 minute ago, northwestsnow said:

BAD.news..

It has to verify though...chin up!

[bluearmy]

It seems from annecdotal evidence the best model for handling the strat over the years is glosea. This model sees a big uptick in upper strat flow second half dec but it doesn't see them propagating down and affecting the trop. that's pretty well the only silver lining at the moment. 

 

[blizzard81]

1 hour ago, bluearmy said:

It seems from annecdotal evidence the best model for handling the strat over the years is glosea. This model sees a big uptick in upper strat flow second half dec but it doesn't see them propagating down and affecting the trop. that's pretty well the only silver lining at the moment. 

 

Glosea has been shown to be an exceptional long range forecasting tool over the last few years. Far superior to ecm.

[Nouska]

34 minutes ago, blizzard81 said:

Glosea has been shown to be an exceptional long range forecasting tool over the last few years. Far superior to ecm.

There are some charts of the GloSea5 strat modelling for the winter of 15/16 in the PDF for presentation to MedCOF5.

Pages ten and eleven.

http://medcof.aemet.es/images/doc_events/medcof5/docMedcof5/presentaciones/MedCOF5_Brookshaw.pdf

I don't think they did a presentation for this winter at the most recent conference.

[mountain shadow]

The weakened PV had provided nothing by way of snow anyway.

At least if it ramps up we might be able to draw in some colder air on the back of a cold front.