Stratosphere and Polar Vortex Watch

[northwestsnow]

6 minutes ago, bluearmy said:

GEFS continues with the trend to take the vortex closer to the pole on a trip back to Canada from Siberia end week 2.

given the strength of the wave 1 on berlin at day 10, its a surprise that the displacement signal wains thereafter

Dont like the sound of this blue.

 

[georgiedre]

I think like others have said that there's conflicting information about the stratosphere and troposphere this year I believe. Could this be causing problems for the weather

[bluearmy]

57 minutes ago, northwestsnow said:

Dont like the sound of this blue.

 

I wouldn’t be getting overly concerned with gefs until we see a tweet ref the eps concurring 

[comet]

8 hours ago, bluearmy said:

GEFS continues with the trend to take the vortex closer to the pole on a trip back to Canada from Siberia end week 2.

given the strength of the wave 1 on berlin at day 10, its a surprise that the displacement signal wains thereafter

the 12z Geopotential heights do not agree with this. See instant weather maps.

 

Edited December 13, 2017 by comet

[bluearmy]

5 minutes ago, comet said:

the 12z Geopotential heights do not agree with this. See instant weather maps.

 

That would be the op rather than the ens ???

[Normal Normal Normal]

10mb is super Stratosphere warming right now. This looks to continue through the last week of December. 

This only ever goes as high as +1200-1800. 

 

500mb of January-February's following 19 years that had Stratosphere warming during this time:
 

Only La Nina (7).

Edited December 13, 2017 by Normal Normal Normal

[Interitus]

8 hours ago, Normal Normal Normal said:

10mb is super Stratosphere warming right now. This looks to continue through the last week of December. 

This only ever goes as high as +1200-1800. 

 

That is geopotential height, warming at 10mb only brings it back up to average -

The significant warming is lower down eg at 50mb -

The picture is similar at 30mb, these temperature anomalies show the increased thicknesses associated with stratospheric Aleutian anticyclone which is displacing the vortex. Greater effects below 10mb would be typical of a Labitzke Canadian warming, however the 60°N 10mb average zonal wind for the composite dates was quite some distance from SSW territory at 18.4 m/s.

 

 

[bluearmy]

The last two ecm ops have both extended the strat ridge at 10hpa further east across Canada rather than retorgressing further west. this is a divergence from gfs and gefs 

[northwestsnow]

2 minutes ago, bluearmy said:

The last two ecm ops have both extended the strat ridge at 10hpa further east across Canada rather than retorgressing further west. this is a divergence from gfs and gefs 

I  assume thats not good news blue.

6z gfs again showing a nice warming -

Edited December 14, 2017 by northwestsnow

[bluearmy]

41 minutes ago, northwestsnow said:

I  assume thats not good news blue.

6z gfs again showing a nice warming -

Not necessarily - at some point the upper strat will likely imprint more consistently across the NH and a stonking great Canadian ridge could be good if it extends far enough east 

[Blessed Weather]

 

[Catacol]

Indeed. A spike in heat flux like that would give the lower strat all kinds of bother....

[Allseasons-Si]

Yes,was showing on the jma graph but not to the extent of that one above,will keep monitoring this to see if another spike appears soon.

[feb1991blizzard]

2 hours ago, Catacol said:

Indeed. A spike in heat flux like that would give the lower strat all kinds of bother....

I don't know if its still there on the 18z but the 18 z does indeed give the lower strat all kinds of bother, in fact it gives bother to the vortex to quite high in the mid strat.

[bluearmy]

The ecm ops are placing the upper strat ridge at 10hpa right above the trop Canadian vortex !!

will it just drift back west or are we looking at something unexpected to happen lower down over time  or will that disconnect continue  ??

[northwestsnow]

10 minutes ago, bluearmy said:

The ecm ops are placing the upper strat ridge at 10hpa right above the trop Canadian vortex !!

will it just drift back west or are we looking at something unexpected to happen lower down over time  or will that disconnect continue  ??

Don't know what to make of that post blue.

At 'ground level' the EC op this morning looks pretty awful!

[Interitus]

1 hour ago, bluearmy said:

The ecm ops are placing the upper strat ridge at 10hpa right above the trop Canadian vortex !!

will it just drift back west or are we looking at something unexpected to happen lower down over time  or will that disconnect continue  ??

Not a disconnect, phase tilt. At any time there may be various Rossby waves propagating upwards, and if conditions are right, downwards. The time between 500mb and 10mb may be 6+ days and upwards propagation is indicated by westward tilt with height, downwards by eastward tilt with height. So it is not unusual for geopotential heights to appear out of sync.

The chart below shows the phase shift from a composite of downward coupling events (Shaw & Perlwitz 2013 - http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00251.1) and it can be seen that initially there is a westward tilt of geopotential from the mid-troposphere into the stratosphere which becomes an eastward tilt with height as the cycle progresses, becoming quite extreme by the end of the process -

A week ago it was suggested that a possible downward coupling event was visible in the Hannah Attard GFS forecast 500/10mb charts, contributing to the ridging off the Pacific coast of North America. This was following a reduction in wind speed in the middle strat which gave a negative vertical wind shear between about the 6th - 8th which provided a potential reflecting surface -

It's possible that some of the later effects of this process are what are being witnessed in the geopotential forecasts, and it's also worth noting Shaw & Perlwitz also suggest that reflection events tend to lead to +ve NAO phase which is the case at the moment and in the near to medium term.

 

 

 

[bluearmy]

Excellent  @Interitus - had a feeling you would make a good post explaining this. 

Previous gefs guidance was that the upper strat ridge would drift further west towards the aleutians but it seems this may not happen in week 2. 

Of course the ecm op could be wrong but at 10hpa it’s usually reliable and to be consistent makes it seem more likely to verify 

[KyleHenry]

5 hours ago, bluearmy said:

Excellent  @Interitus - had a feeling you would make a good post explaining this. 

Previous gefs guidance was that the upper strat ridge would drift further west towards the aleutians but it seems this may not happen in week 2. 

Of course the ecm op could be wrong but at 10hpa it’s usually reliable and to be consistent makes it seem more likely to verify 

Gefs’ phantom wave signal at the 300 hour range is just not containing enough energy to reverse the U winds

Reversal was there for the taking, but it matters not this year as the Troposphere is calling the shots. 

 

Pacific is to waken with two forecasted Super Typhoons at the 240z range.

Pacific WAA getting the nitro. New Rossby wave formation in the period 25th-29th December. 

Nothing too exciting but no stagnation either. 

[Summer Sun]

 

[Normal Normal Normal]

I understand what you are saying with winds. But research is showing something like 21/24 correlation with 10mb warming in December and January negative NAO. Many of the analogs didn't have 10mb air temperature correlation or zonal wind event, and yet became -NAO on +20-35 day lag. Models are crazy with 10mb warming through December right now (it's already happening).

Edited December 16, 2017 by Normal Normal Normal

[JeffC]

3 hours ago, Normal Normal Normal said:

I understand what you are saying with winds. But research is showing something like 21/24 correlation with 10mb warming in December and January negative NAO. Many of the analogs didn't have 10mb air temperature correlation or zonal wind event, and yet became -NAO on +20-35 day lag. Models are crazy with 10mb warming through December right now (it's already happening).

https://earth.nullschool.net/#current/wind/isobaric/70hPa/overlay=temp/orthographic=-0.87,77.65,363/loc=-143.732,58.049

This shows a temperature differential at 70 hpa but nothing obvious at 10 hpa...pity there isn't a greater pressure resolution as it would be interesting to see where the warm sector starts and finishes with greater accuracy.

[joggs]

GloSEA recently lost its signal for Jan warming 're what Fergie states.

All eyes to meto further outlook.

[Dennis]

Goodmorning well if the setting will be succeed  there is NO SW-ly at christmas days

[bluearmy]

Evolving gefs theme (apart from returning the strat vortex closer to the pole ) is to the edge the highest height anomoly into the n Atlantic 

In tandem with the Alaskan high anomoly sticking around 30/50 hpa, I wonder if this provides for a strat split to ensue from Alaska across to Greenland in time with a residual chunk of vortex left over n America whilst the majority is still on th Asian side ?????

The ecm to day 10 generally stays with continuity from yesterday’s 12z which is available on the Berlin site (upper vortex drifting towards n Scandi from n Siberia