Stratosphere and Polar Vortex Watch

[Summer Sun]

 

[karyo]

10 hours ago, Summer Sun said:

 

The question is will there be further warming episodes and if not for how long will we continue to benefit on the troposphere from the recent SSW.

For a time, the gfs showed the vortex reorganising quite quickly at 30hpa level but more recent runs have gone back to a more fragmented vortex. The 0z is not far from another split towards the end of the run.

[Singularity]

10 hours ago, Summer Sun said:

 

Really not a fan of the way he provides summaries but includes no context or implications, leaving the door wide open to all manner of misinterpretations.

How many reading this are going to know off the top of their head that this is part of the process required to downwell the negative zonal anomalies to the surface?

[Interitus]

1 hour ago, Singularity said:

Really not a fan of the way he provides summaries but includes no context or implications, leaving the door wide open to all manner of misinterpretations.

How many reading this are going to know off the top of their head that this is part of the process required to downwell the negative zonal anomalies to the surface?

Is it?

[Singularity]

6 minutes ago, Interitus said:

Is it?

Er... as far as I know? Or at least it helps it along?

Regardless, I know there are those who'd see recovering westerlies at 10 hPa and assume bad news for us at the surface at the same time or soon after.

[bluearmy]

1 hour ago, Singularity said:

Er... as far as I know? Or at least it helps it along?

Regardless, I know there are those who'd see recovering westerlies at 10 hPa and assume bad news for us at the surface at the same time or soon after.

I agree in general with your thoughts about his tweet 

[Bristawl Si]

1 hour ago, bluearmy said:

I agree in general with your thoughts about his tweet 

Hmm...i questioned this guy's tweets the other day and got slaughtered for doing so! U have to laugh on here sometimes.

[Summer Sun]

 

[karyo]

Any thoughts on whether we can expect further strato warmings in the next few weeks?

[Weather-history]

Judah Cohen in his last blog made an interesting observation about the January 2013 warming event 

"For now, I think a good analog could be the last MMW/PV split in early January winter 2012/13.  In Figure iv I show the PCHs plot from that winter with some severe winter weather events highlighted when the PCHs pulsate red or warm across the Northern Hemisphere (NH).  That winter it took until March for the most positive PCHs to reach the mid to lower troposphere and it could take a while for something similar to occur.  I for one am not expecting winter’s last hurrah to be this weekend."

 

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

Any thoughts by others?

I always wondered why the massive blocking came about two months after the warming event.

Edited January 21, 2019 by Weather-history

[Summer Sun]

 

[chionomaniac]

I reckon that it is too late for any further warming’s that will affect the business end of winter. 

[Kentish Snowman in Yorks]

4 hours ago, chionomaniac said:

I reckon that it is too late for any further warming’s that will affect the business end of winter. 

Hi Chiono.  Do you feel there are any specific reasons why we are still not seeing any HLB (at least in our part of the Northern Hemisphere) showing in the models given we are approaching a month down the line since the SSW?

The EC46 and Glosea were very confident of this from the end of the month onwards and I am just interested to see how you see things panning out especially since you don't see any further warmings in the near future?

[summer blizzard]

36 minutes ago, Kentish Snowman said:

Hi Chiono.  Do you feel there are any specific reasons why we are still not seeing any HLB (at least in our part of the Northern Hemisphere) showing in the models given we are approaching a month down the line since the SSW?

The EC46 and Glosea were very confident of this from the end of the month onwards and I am just interested to see how you see things panning out especially since you don't see any further warmings in the near future?

The short of it is that the initial tropospheric response (actually a little better and quicker than i thought) occured in the wrong place and that is largely because we split the vortex into three lobes rather than two (that is however a factor in why zonal winds have stayed negative so long).

Basically the initial surface split put the blocking over the North Pacific side of the Arctic (normal and not bad per say down the line) but instead of getting the other lobe either over canada or scandinavia, we got both. This meant that we needed an ultra amplified atlantic ridge or we would be at risk of zonality (our current pattern is not as bad as it could have been, there are other ssw's which have done worse).

We may have other chances (we should see peak effects in the trop between now and feb 10th so look for other opportunities and continued cold zonality. 

The tropics have not been massively helpful either. The Nino has chosen the past month to weaken a bit so we have seen enhanced trades in the pacific which encourage an enahnced azores high.

[Summer Sun]

 

 

[feb1991blizzard]

21 hours ago, chionomaniac said:

I reckon that it is too late for any further warming’s that will affect the business end of winter. 

Could still give us a cracking March and early April though!!!!   -   i am guessing with your location though that you would only be interested in any further SSW from a scientific point of view though.

[Summer Sun]

 

[Summer Sun]

 

[Bristawl Si]

"...the westerlies are kicking back in at and above 30km!"

As usual no context.....is the bit i've quoted highly significant? Timescales to affect trop and weather at surface?

[Froze were the Days]

What I've read over the last few days...the down welling continues to affect the trop as it has been a very slow response and will continue to into early February so not sure Mr Petagna's remarks above will have much influence over the coming weeks on the what we'll experience. Please correct me if I'm wrong.

Edited January 23, 2019 by Froze were the Days

[joggs]

Is it possible that the downwelling westerly's could put pressure on the lower strat/trop to speed things up,sort of speak?

Meaning the easterlies receive a kick up the weeble?.

Edited January 23, 2019 by joggs

[Altostratus]

Knowing our luck there will be an instant downwelling of the w'lys that negates the e'lys! Seriously, given the lagged response and the fact that the PV will be weakening at the back end of winter anyhow, I'm led to believe its influence would be minimal. Let's hope we have some HLB in place prior to that though. 

[mb018538]

2 hours ago, joggs said:

Is it possible that the downwelling westerly's could put pressure on the lower strat/trop to speed things up,sort of speak?

Meaning the easterlies receive a kick up the weeble?.

I wouldn’t have thought so at this stage - easterlies are still making their way down....the westerly recovery is at the top. It’s just a slow old process compared to the super quick response last winter.

[mushymanrob]

so, if things have returned to normal in the stratosphere, does that suggest that by spring, (march 1st) . 'normal' conditions are most likely at surface levels?

[kold weather]

Depends on how quickly the westerly winds downwell, and also to a certain extent how early/late the final warming of the PV is. For example the Jan 2013 SSW didn't really mix down until late Feb and the effects lasted through March and early April. This one may not hold as long but its certainly a possibility that we keep this wonky mix for a while yet.