Stratosphere Temperature Watch 2015/2016

[wishingforsnow]

24 minutes ago, -Bomber- said:

The 2013 SSW occurred in January and we felt it weather wise that March. If and I emphasis if one was to occur at the beginning of February, would we be waiting until March again to see possible cold or how soon could its effects be felt? I know a SSW doesn't guarantee cold

I'm sure we started to feel the effects earlier than March? I recall it got significantly colder again after the SSW in mid February 2013 then in March we got the widespread snowfall and prolonged cold. 

Also the length of time for the effects of a SSW to be felt can be anything from a few days to a few weeks.

As mentioned by others a SSW doesn't gurantee cold but having blocking in place and a mild weather pattern does help in order for the outcome of a SSW to be a flip to cold.

Edited January 21, 2016 by wishingforsnow

[bluearmy]

20 minutes ago, -Bomber- said:

The 2013 SSW occurred in January and we felt it weather wise that March. If and I emphasis if one was to occur at the beginning of February, would we be waiting until March again to see possible cold or how soon could its effects be felt? I know a SSW doesn't guarantee cold

There are no hard and fast rules re SSW's and their effects, especially relating to specific global locations. There are classic downwelling wave responses which, if they propagate effectively will deliver a neg AO response at varying timescales following an event.  2013 was pretty good in that regard.  Basically, an SSW will load the dice in favour of cold for the mid latitudes. That's the best place to start.  Beyond that, wait for an SSW to actually appear in the NWP and then hope to see a quick trop response in the modelling. That gets you a cold spell almost straight away if you are lucky enough to be in the right place to receive the cold.  But there may not be a quick response.  anyone expecting to get quick answers is going to be disappointed. As ever, patience required. 

[Trom]

I seem to remember that when I was doing back ground reading on SSW last year the academic view was between two weeks to two months for the effect to really be felt in the trop.  So certainly some variability there if my memory is correct.

[Nouska]

It's only a wee wedge of the northern hemisphere but interesting to see the warming sweep in from the west and the 30mb vortex relocate ahead of it.

http://brunnur.vedur.is/kort/ecm0125/2016/01/21/12/ecm0125_nat_gh30_t30.html

[chionomaniac]

24 minutes ago, Trom said:

I seem to remember that when I was doing back ground reading on SSW last year the academic view was between two weeks to two months for the effect to really be felt in the trop.  So certainly some variability there if my memory is correct.

With a split vortex the trop can be affected by the time the downwelling strat split reaches the trop - pretty quickly. Look at late Jan/early Feb 2009.

[Snowman.]

1 hour ago, wishingforsnow said:

I'm sure we started to feel the effects earlier than March? I recall it got significantly colder again after the SSW in mid February 2013 then in March we got the widespread snowfall and prolonged cold. 

Also the length of time for the effects of a SSW to be felt can be anything from a few days to a few weeks.

As mentioned by others a SSW doesn't gurantee cold but having blocking in place and a mild weather pattern does help in order for the outcome of a SSW to be a flip to cold.

I may be wrong but I recall chino talking about the imediate effect which is what we saw in Jan 2013 with the slider, then again in Feb we saw an Easterly that was so close to delivering but went too far south but was very cold. March came and we saw NAO tank it.

[Trom]

2 hours ago, chionomaniac said:

With a split vortex the trop can be affected by the time the downwelling strat split reaches the trop - pretty quickly. Look at late Jan/early Feb 2009.

Yes agreed it can be faster.  I don't remember the confidence interval that was used for that range of values.  I remember at the time being struck by the size of the range rather than its maximum and minimum  values.   Was 2009 an outlier or is this recurring theme?  We certainly have had interesting background variables in the trop this season with an el nino event coupled with warm Indian ocean waters, the Kara heights, a series of rossby waves hitting the strat and a hurricane in the Atlantic in January.  Now we get to see how a warming will interact with these variables.  A lot water to flow under the bridge before we know where we stand there but it should be interesting to how the pieces of the jigsaw fall.

Edited January 22, 2016 by Trom

[KyleHenry]

Wave 1 energy remains present as the commencement of EAMT  on 31st Jan. 

-10 m/s reversal creeps down to 5hPa level.

[Abyss]

@ Kyle What does that mean in basic terms,criteria for a SSW? I'm assuming it's good going by the like count ha

Edited January 22, 2016 by -Bomber-

[Alexis]

Quick question - the warming appears on the other side of the hemisphere. Does it always warm on that side, or can it warm evenly across the arctic? What effects does it have where exactly the warming takes place? I see directly above the UK the stratosphere is actually very cold.

[Recretos]

Here is my latest animation, from 00z GFS showing geopotential height layers in 3D. Top down are 10mb, 30mb, 70mb, 250mb and 600mb. You can see the upward induced split, the effect of the Azores high, reaching into lower strat, and the downward propagating wave from the strat wave 1, creating the Alaska ridge in the process. 

 

 

GEFS also sees the connection of the strong wave 1 with the troposphere, so here we have our fast coupling response. The Alaskan ridge is not all strat induced, but is greatly helped by the strat wave, makin more room for the ridge. 

     

Edited January 22, 2016 by Recretos

[Dennis]

Im realy interested in this weather-stuff ; i hope to learn more about the effects on blocking systems

[KyleHenry]

2 hours ago, -Bomber- said:

@ Kyle What does that mean in basic terms,criteria for a SSW? I'm assuming it's good going by the like count ha

The ECMWF model has edged into range of the GEFS in regards to the very early beginnings of a mountain torque event (Asia). Pre-cursor to a SSW.

Wave 1 is well underway and it is comparison time for forecasted kinetic energy against actual kinetic energy. Aka temperatures shown on models.

Confidence increases for SSW to occur (85%).

Watch Recretos' 3D graphic modelling of the raw data instead of a linear chart for best understanding.

[wishingforsnow]

5 minutes ago, KyleHenry said:

The ECMWF model has edged into range of the GEFS in regards to the very early beginnings of a mountain torque event (Asia). Pre-cursor to a SSW.

Wave 1 is well underway and it is comparison time for forecasted kinetic energy against actual kinetic energy. Aka temperatures shown on models.

Confidence increases for SSW to occur (85%).

Watch Recretos' 3D graphic modelling of the raw data instead of a linear chart for best understanding.

Awesome news 

The Model thread is getting ridiculous  how can some users call judgment on the weather for the rest of winter (and summer (!)) based on a set of model runs that are a week to 10 days away. 

Its best to look at the big picture. And it looks like a SSW event may be close by in our midst. Hopefully it goes the right way in terms of achieving cold for the UK 

Edited January 22, 2016 by wishingforsnow

[Dennis]

What will happen so quickly on the 10hpa between 20/1 to 30/1 2016?

[karyo]

Every GFS run is now showing consistency in terms of the appearance of the major warming in the far reaches of FI.

At 30hpa level the 12z has the best looking warming of the season so far with the weakening vortex getting squeezed from both sides.

This needs to move in the below 300 hour timeframe by the end of the weekend to get us feeling a bit more confident.

Karyo

[Snowman.]

If GFS strat charts are anything to go by it moves the PV to Scandi before moving it back to greenland as the second much major warming is modelled 

[Chris1986]

6 hours ago, wishingforsnow said:

Awesome news 

The Model thread is getting ridiculous  how can some users call judgment on the weather for the rest of winter (and summer (!)) based on a set of model runs that are a week to 10 days away. 

Its best to look at the big picture. And it looks like a SSW event may be close by in our midst. Hopefully it goes the right way in terms of achieving cold for the UK 

Couldn't agree more. Fact is a massive (hopefully) SSW Is underway and 90% have already got the flip flops out for summer. Models are confused as anything at the moment and the mean / control / operational  data Is next to useless due to the massive swings in the numerous permutations, my money is definitely not on the mean / control / operational  

Edited January 22, 2016 by Chris1986

[wishingforsnow]

14 minutes ago, Chris1986 said:

Couldn't agree more. Fact is a massive (hopefully) SSW Is underway and 90% have already got the flip flops out for summer. Models are confused as anything at the moment and the mean data Is next to useless due to the massive swings in the numerous permutations, my money is definitely not on the mean  

Yes and regardless of what is happening in the USA amplifying the jet, should a SSW occur it could mean that the cold will arrive over here too. It's just a matter of patience and seeing if and when it will pay off but the periststence of strat warming is what's giving me hope we will see a change unlike 2013-14 when the snowy cold winter for them (which had been cold since the start) meant a mild wet winter for us with no sign of a SSW possibility to rescue us.

[Chris1986]

8 minutes ago, wishingforsnow said:

Yes and regardless of what is happening in the USA amplifying the jet, should a SSW occur it could mean that the cold will arrive over here too. It's just a matter of patience and seeing if and when it will pay off but the periststence of strat warming is what's giving me hope we will see a change unlike 2013-14 when the snowy cold winter for them (which had been cold since the start) meant a mild wet winter for us with no sign of a SSW possibility to rescue us.

We'll I suppose If the polar vortex gets pushed over us It's going to be fricken cold, I particularly like the idea of a north westerly as far as I can see there is every possibility for us to go back into the freezer, if you look at 3 runs on 00z  6z 12z for the same time the difference is considerable and it's all (I think) to do with models handling the SSW.

I agree with you 100%.

[Singularity]

It now looks likely to me that a SSW will occur at a time when the trop pattern is getting into a setup which favours properly cold conditions developing across the UK and much of Europe.

In light of which, am I right in thinking we really need to avoid a displacement event, as the location of the warming means the vortex would just be shoved back toward Canada?

A split event, on the other hand, would be kicking the vortex while its down - or more likely, stamping it right out. Worth the gamble?

[Recretos]

This warming is very undefined as such, and the only response as I have shown in 3D in the first phase is the Alaskan ridge formation. Do not also forget about the unusually strong Azore/African ridge area.

And lets keep the strat splits out of the discussion since there is wave1 domination atm, and first deal with the displacement.

And I am not a pesimist, but a cautius realist. We are not dealing with a major SSW, like the 09 one or 2013. A major SSW is not even forecasted yet, except ocasionally by some individual GEFS perturbations. 
We are dealing with a minor SSW until further notice, and so the rules of the game are different. Things could go in Europe's favour, but sweat and tears are needed for that. So lets not jump the wagon, shall we...

Just a friendly reminder.

 

Edited January 22, 2016 by Recretos

[Chris1986]

Now this is seriously cool. Live time data cracking the pv in 2013 SSW

epv_7mb_20121215_20130128.mp4

 

Edited January 22, 2016 by Chris1986

[blizzard81]

1 hour ago, Recretos said:

This warming is very undefined as such, and the only response as I have shown in 3D in the first phase is the Alaskan ridge formation. Do not also forget about the unusually strong Azore/African ridge area.

And lets keep the strat splits out of the discussion since there is wave1 domination atm, and first deal with the displacement.

And I am not a pesimist, but a cautius realist. We are not dealing with a major SSW, like the 09 one or 2013. A major SSW is not even forecasted yet, except ocasionally by some individual GEFS perturbations. 
We are dealing with a minor SSW until further notice, and so the rules of the game are different. Things could go in Europe's favour, but sweat and tears are needed for that. So lets not jump the wagon, shall we...

Just a friendly reminder.

 

I think you mean jump the gun

[Methuselah]

6 minutes ago, blizzard81 said:

I think you mean jump the gun

That's a bit unfair, blizzard81...How learned are you when it comes to Slovenian idioms?