Stratosphere Temperature Watch 2013/2014

[Recretos]

 

misunderstanding recretos. both statements are clearly false. the points being made were pertinent to that gfs op run only.

 

 

As I suspected. Thank you.

 

Anyhow, GEFS plays along with GFS (or vice-versa) and slightly increases the warming.

Important notice: GEFS does not postpone the warming like GFS sometimes does by always keeping it in the 384h period. It still has the same amount of warming that was there 4 days ago in FI at the same date, and just evolves it further. If you would see the animation, it is slowly increasing the warming and moving it more to the pole. So GEFS has almost a surreal consistency. Not to mention that this is an ensemble mean, and specific perturbations go up to +5 max. temp at 10mb.  I also made verification by comparing old GEFS runs (ensemble means) to the analysis for current time, and they were mainly colder than the reality, of course due to the fact that it is an ensemble mean and a lower resolution, so it can also be less intense than operational or control runs. Speaking of control runs, they weren't bad actually for the FI when I did the comparison of current state and the FI forecasts 2 weeks ago. But the control seemed to have a really too cold vortex core. Of course I have to add that this was verification on a short scale and does not necessarily reflect the long term statistics. 

 

Tho if we look at the verification for the last month, GEFS mean does indeed have a negative temperature and height bias, basically meaning that it has a slightly too strong vortex in the FI. I do believe that this is the ordinary GEFS version being verified and not the bias-corrected version.

 

 

 

Ok, now for the actual GEFS charts. The control run does seem to have big personality issues with the vortex.

 

 

 

 

 

Speaking of personality issues and biases, the GEFS BC (Bias Corrected) run seems to mitigate just that what I was noticing in the first part of the post (about the GEFS bias), as one would expect of course, since it is a bias correction.

 

 

 

 

Edited January 12, 2014 by Recretos

[bluearmy]

First we hear that there is no connection between mid-strat and troposphere, and now we hear that the tropospheric patterns can't be a precursor to SSWs. I wonder what's next.   Though that "not" might be put there by mistake.  Or maybe I am not interpreting this statement the right way in the first place, in which case please do not hesitate to correct me.  

 

 

misunderstanding recretos. both statements are clearly false. the points being made were pertinent to that gfs op run only.

[feb1991blizzard]

Warming continued on 18z, differences in terms of locale but the another run potentially showing the start of a significant warming, would like to see more consistency over the next 24 hours to be sure and also looks like a displacement type to me?  correct me if im wrong.

[chionomaniac]

That proposed Aleutian low/ Siberian high could well be feeding back into the strat with the latest wave breaking warming the best signalled yet. From what I have seen from the runs over the last few days, Feb 5th could be an important stratospheric day this winter. 

[Snowy L]

Warming continued on 18z, differences in terms of locale but the another run potentially showing the start of a significant warming, would like to see more consistency over the next 24 hours to be sure and also looks like a displacement type to me?  correct me if im wrong.

 

Yeah with wave-1 the vortex will just be displaced from the pole. It would be nice to see something similar to last year where wave-2 shortly followed the wave-1-lead displacement to give us a split vortex, but I don't think any short-midterm set ups support any tropospheric-lead wave-2 breaking, as far as I know.

[Panayiotis]

GFS 18z maintaining the warming @10hPa:

Filtering slowing down @30hPa;

[DELETED]

Hi there i had noticed about 9 oclock this morning the warming at 10hpa had slowed down, but i believe the runs are now being up dated ?

[Ruben Amsterdam]

Because this possible warming is troposphere driven (right?), runs will vary significantly. Yes, the 06z run is almost completed now. In this run warming is delayed, but the cold vortex core remains stretched. The last charts show a warming again. (Positioning and shape similar to yesterdays 18z, but warming is less pronounced.) Far too much inconsistency from run to run to draw any conclusions yet.

 

Any news from the GEFS?

Edited January 13, 2014 by Ruben Amsterdam

[Recretos]

GEFS 06z continues the trend, now reaching max. -14 deg. with ensemble mean at 384h.

 

 

 

And the control ramps it up to +11. Note that this is the bias corrected control run. I couldn't plot the bias-corrected ensemble mean above, because it is not available yet and I am late for work.

 

 

 

Regards.

[DELETED]

GEFS 06z continues the trend, now reaching max. -14 deg. with ensemble mean at 384h.

 

 

 

And the control ramps it up to +11. Note that this is the bias corrected control run. I couldn't plot the bias-corrected ensemble mean above, because it is not available yet and I am late for work.

 

 

 

Regards.

So the warming is still showing ?!

[bluearmy]

 

So the warming is still showing ?!

 yes ben - it is

[DELETED]

   yes ben - it is

Thats great! sorry im not too hot on this. If we were to have a cold spell from this what sort of timescale will we be looking at. 1st week of Feb ? thanks

[mountain shadow]

Ben,

 

The warming is in the upper Stratosphere. If it does actually occur by the end of the month then the downwelling can take anything from a couple of days to a few weeks. So a date of around 10th February is my guess before colder weather arrives.

 

That is of course if the warming verifies.

[DELETED]

Ben,

 

The warming is in the upper Stratosphere. If it does actually occur by the end of the month then the downwelling can take anything from a couple of days to a few weeks. So a date of around 10th February is my guess before colder weather arrives.

 

That is of course if the warming verifies.

Thanks for the clarification! When will we be able to know for sure ? thanks. im not trying to annoy you i swear.

[weatherguy]

I know we've had warming events, but is this the first event this winter that can be classified as a genuine SSW?  If so, how does this forecast compare with last year's major SSW in terms of strength?  (Yes I know the predicted impact of warming isn't an exact science however at the tropospheric level yet)

[mountain shadow]

Thanks for the clarification! When will we be able to know for sure ? thanks. im not trying to annoy you i swear.

 

If I knew the answer to that, i'd be a millionaire. :-0

 

Hopefully the warming signals increase and continue and we may start to see the tropospheric model output beginning to react in about a week to ten days time at the outer range of its output.

[The PIT]

Ben,

 

The warming is in the upper Stratosphere. If it does actually occur by the end of the month then the downwelling can take anything from a couple of days to a few weeks. So a date of around 10th February is my guess before colder weather arrives.

 

That is of course if the warming verifies.

Doesn't that all depend on where the vortex decides to split? We may end up on the mild side.

[feb1991blizzard]

Doesn't that all depend on where the vortex decides to split? We may end up on the mild side.

 

TBH though, I think if we got a split SSW which fully downwelled, I would expect to get more than one bite of the cherry and at this time of year I would suggest we would have to be mighty unlucky at least not to have at least a cold snap during Feb.

[bluearmy]

fellas - patience. we are not forecast a ssw as yet. i doubt anyone will want to call that until we see it showing below T300 consistently. the specific definition to call a ssw are quite limited. also. we may get a favourable downwelling of revered zonality without a ssw actually being called. on top of this, i currently see a dispacement looking more likely than a split (unless we get more wave 2 following this uptick in wave 1).

[feb1991blizzard]

fellas - patience. we are not forecast a ssw as yet. i doubt anyone will want to call that until we see it showing below T300 consistently. the specific definition to call a ssw are quite limited. also. we may get a favourable downwelling of revered zonality without a ssw actually being called. on top of this, i currently see a dispacement looking more likely than a split (unless we get more wave 2 following this uptick in wave 1).

 

I agree with everything said apart from the fact that isn't an SSW definition a reversal of zonal winds at 60N and 10mb, yes I agree we are nowhere near forecast any type of SSW yet let alone a split one.

[cooling climate]

I may be wrong ( would not be the 1st time) but it looks to me on the 1mb temperature

charts in the last few runs as if the warming is slowly moving back west, entering the

Arctic more from our locale rather than from mid-Russia northward.

If this is the case then this would be much more benificial for us in that we would see a

much quicker response I would imagine.

[weatherguy]

Relax guys, was just a question...I understand a strong warming was being forecast and simply wondered what the parameters for an SSW were in relation to this warming.

Edited January 13, 2014 by weatherguy

[Interitus]

we may get a favourable downwelling of revered zonality

 

Freudian slip?

[DELETED]

Latest runs on netweather.

 

[feb1991blizzard]

All the hallmarks of a displacement SSW here? at the 1mb level.

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014011318&var=HGT&lev=1mb&hour=384

 

 

Only problem though is the actual temperatures at 10mb seem to have peaked and look to be subsiding, during the SSW last year, the bright reds were just getting brighter every run, just an observation although maybe just T300+ run variability, also agree it would be preferable to see this wave 1 activity followed up by some wave 2 activity.