Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Stratosphere and Polar Vortex Watch


Paul

Recommended Posts

Posted
  • Location: Neath Valleys, South Wales 109m asl
  • Location: Neath Valleys, South Wales 109m asl
1 minute ago, feb1991blizzard said:

I know i was very confident of a severe Easterly about 1 months before based on some of the GFS FI strat charts, i told my mates to expect something severe in February in terms of snow, i cannot prove my thoughts because i was banned off the forum for the whole month so i only started posting again on 1st March with a good few inches of snow and drifting and a severe wind chill outside.

Appreciate that but my point was that it didn't model it correctly then so there's a chance it may not be again.

 

Link to comment
Share on other sites

Posted
  • Location: Near King's Lynn 13.68m ASL
  • Weather Preferences: Hoar Frost, Snow, Misty Autumn mornings
  • Location: Near King's Lynn 13.68m ASL
18 minutes ago, bluearmy said:

That would have been the old op, not the V3 which was running in parallel at the time. i think its the reliability of the V3 which is being questioned 

Sorry, the context was not to compare with the FV3, but to point out that all the strat models flipped massively inside one day. It comes from the Lee et al. anticyclonic wave breaking paper.

Link to comment
Share on other sites

Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
Just now, ALL ABOARD said:

Appreciate that but my point was that it didn't model it correctly then so there's a chance it may not be again.

 

To be clear by the way, all i am writing off at the moment is an SSW for a good few weeks, not a severe spell of cold weather for the rest of winter.

Link to comment
Share on other sites

Posted
  • Location: Longden, Shropshire
  • Location: Longden, Shropshire
5 hours ago, feb1991blizzard said:

biggest worry is only the odd straggler had an SSW in late winter too, need to hope the GLOSEA5 performs like it did last year.

I thought GLOSEA5 picked up on the SSW quite well last winter, just didn’t benefit us?

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
2 minutes ago, Don said:

I thought GLOSEA5 picked up on the SSW quite well last winter, just didn’t benefit us?

It did well in the strat but must of modelled cold spells because surely if it were at odds with the EC46, the Met Office wouldn't have been so bullish about the Easterly for so long, it must have mis-modelled a QTR or some kind of pattern that would have gave us a cold Easterly as 'Easterly' and 'Snow' were words that were rarely missing from the updates.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Wantage, Oxon
  • Weather Preferences: Hot, cold!
  • Location: Wantage, Oxon
29 minutes ago, feb1991blizzard said:

It did well in the strat but must of modelled cold spells because surely if it were at odds with the EC46, the Met Office wouldn't have been so bullish about the Easterly for so long, it must have mis-modelled a QTR or some kind of pattern that would have gave us a cold Easterly as 'Easterly' and 'Snow' were words that were rarely missing from the updates.

I think last year messed with all of us, pros included, wasn't the problem that the vortex split into three which left one bit really badly placed for us?

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll
2 hours ago, Mike Poole said:

I think last year messed with all of us, pros included, wasn't the problem that the vortex split into three which left one bit really badly placed for us?

They were expecting it to move down through the strat layers: it didn't do that till it split properly in February and even then it was a slow process that left us with a cold spring and all the persistent summer -NAO. Just looking at the charts, I'm wondering if the zonal spell will be as bad as some are thinking. The vortex is well north of Canada and in a position to bring polar shots from the NNW rather than usual due westerlies.

  • Like 7
Link to comment
Share on other sites

Posted
  • Location: Wantage, Oxon
  • Weather Preferences: Hot, cold!
  • Location: Wantage, Oxon
1 minute ago, Gael_Force said:

They were expecting it to move down through the strat layers: it didn't do that till it split properly in February and even then it was a slow process that left us with a cold spring and all the persistent summer -NAO. Just looking at the charts, I'm wondering if the zonal spell will be as bad as some are thinking. The vortex is well north of Canada and in a position to bring polar shots from the NNW rather than usual due westerlies.

Yes, agreed, NW or NNW flow, with a strong jet running to the south is something I've been musing for a while, might not be utterly freezing (and unlikely to deliver much snow to my vicinity) but would deliver for many further north, I would expect.  But IMBY concerns aside, it will be fascinating to see how this winter evolves, and who predicted it!!

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: Weymouth, Dorset
  • Location: Weymouth, Dorset

Wave #2 action pepping up as we head through Dec?

27-ecmwfzm_ha2_f240.thumb.gif.02b908d6504e811444b461af4dacf734.gif

 

Also, I've definately seen worse U wind forecast profiles...

ecmwfzm_u_f240.thumb.gif.5290715975d27c40f696f15a28235480.gif

 

Edited by s4lancia
  • Like 7
Link to comment
Share on other sites

Posted
  • Location: Carryduff, County Down 420ft ASL
  • Location: Carryduff, County Down 420ft ASL
2 minutes ago, s4lancia said:

Wave #2 action pepping up as we head through Dec?

27-ecmwfzm_ha2_f240.thumb.gif.02b908d6504e811444b461af4dacf734.gif

 

Also, I've definately seen worse U wind forecast profiles...

ecmwfzm_u_f240.thumb.gif.5290715975d27c40f696f15a28235480.gif

 

Indeed, normally we would salivating over the latter chart with almost a full reversal over the pole.

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: Roznava (Slovakia) formerly Hollywood, Co Wicklow
  • Weather Preferences: continental climate
  • Location: Roznava (Slovakia) formerly Hollywood, Co Wicklow
1 hour ago, Glacier Point said:

Looks to me as if the early winter skirmishes are confirming two things:

  • stratospheric polar vortex weaker than normal;
  • stratospheric polar vortex displaced towards the Siberian Sector.

That should temper enthusiasm for proper early season cold across Europe as it doesn't favour sufficient blocking strength to displace cold air masses south and westwards to the degree necessary.

Tropospherically, our low frequency base state, which is nicely evident across OLR anomaly fields in the Tropics....

olr_anom_7day.thumb.gif.56d75a363c508609b4bc8f1986bcf5a5.gif

... is about to undergo destructive interference in the next two weeks as a more coherent convective wave develops and pushes further east. This is a good signal for the PV to rev up a bit and westerly influence extend across the North Atlantic.

When this relaxes, the low frequency state should take hold again on the hemispheric pattern. Deep upper low in the North / North-east Pacific a facet of this which should to further reinforcement of the weaker and displaced (Wave 1) SPV.

Weak level blocking expected to re-establish to our north and north-east within a broadly north-west flow regime for second half of December. It will be interesting to see how much angular momentum rebounds in the next 2 weeks after being driven to lowish values of late, as this will be key to how much amplification in the upper level flow across the Pacific and Atlantic can be generated to tease out Arctic air masses within that regime.

@Glacier Point, nice to hear your thoughts, would something like this from latest CFS weeks 3 and 4 reflect your thoughts well, re. blocking to north, north/east?

wk3.wk4_20191126.z500.gif

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

From the beeb today in the LFR

Quote

However, we are still monitoring the Arctic stratosphere, as there is a chance that developments here could lead to a spell of colder weather in December. At the moment, whilst there is some uncertainty in the forecast, we don't see any long, drawn out spells of wintry weather developing.

You read it in full in the media thread. It's in the last section after the General Election forecast.

https://www.netweather.tv/forum/topic/69782-weather-in-the-general-media-newspaper-features-etc/page/248/?tab=comments#comment-4103736

 

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Kirkcaldy, Fife, Scotland 20m ASL
  • Weather Preferences: Snow,Thunderstorms mix both for heaven THUNDERSNOW 😜😀🤤🥰
  • Location: Kirkcaldy, Fife, Scotland 20m ASL

 

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Wantage, Oxon
  • Weather Preferences: Hot, cold!
  • Location: Wantage, Oxon

Well if today's 0z output is anything to go by on stratobserve plots, then the signal for a SSW is increasing amongst ensemble members:

image.thumb.jpg.fdc35f9ea9cec21afaed08a1c5875abd.jpg

The stand off with the op run continues, however.  

image.thumb.jpg.3c97731b455d87c7b4f8c5b795bf9b7c.jpg

8 runs showing reversal at T384, and some hinting at a split, and this is up from two days ago, so could be a red herring, but could also be GEFS sniffing something, we will see...

  • Like 8
Link to comment
Share on other sites

Posted
  • Location: Weymouth, Dorset
  • Location: Weymouth, Dorset

Good to see GEFS back to hints of an SSW again. Like @Mike Poole says, hopefully GFS comes on board soon as well.

Does anybody know why the Amy Butler graph is no longer updating with GEFS forecast? (it stopped about a week ago)

u_60N_10hpa_gefs.thumb.png.71ac1ea6b71cbad346a1e272d17569a4.png

Edit: Sorry, brain fade moment, meant Hannah Attard!

Edited by s4lancia
  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Calgary, Canada. Previously, Saffron Walden (Essex/Herts border), United Kingdom
  • Weather Preferences: Continental:Warm dry summers, cold snowy winters
  • Location: Calgary, Canada. Previously, Saffron Walden (Essex/Herts border), United Kingdom
16 minutes ago, ALL ABOARD said:

gfsnh-10-324.thumb.png.e4341d943c7f5be179e4e9e652879c82.png

Can't be far away on this chart surely? 

My biggest concern is that it's not really interacting with the PV as it does in some other runs. Ideally we want it nudged away from the pole and even better if we can see a split. 

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans
7 hours ago, ALL ABOARD said:

gfsnh-10-324.thumb.png.e4341d943c7f5be179e4e9e652879c82.png

Can't be far away on this chart surely? 

Nothing hugely notable re heights - strat vortex continues to be displaced Kara/Barents 

ec op ref Berlin continues to show reversal above 70N post day 7 up to around 10 hpa by day 9/10 so good continuity here  - presumably the wave working up from the trop due to the Siberian upper ridge that gets injected into the polar field ...... crude assessment but seems logical .....

  • Like 9
Link to comment
Share on other sites

Posted
  • Location: NorthseabeachTown
  • Location: NorthseabeachTown
14 hours ago, s4lancia said:

Good to see GEFS back to hints of an SSW again. Like @Mike Poole says, hopefully GFS comes on board soon as well.

Does anybody know why the Amy Butler graph is no longer updating with GEFS forecast? (it stopped about a week ago)

u_60N_10hpa_gefs.thumb.png.71ac1ea6b71cbad346a1e272d17569a4.png

Edit: Sorry, brain fade moment, meant Hannah Attard!

After contacting her, she talked about a glitch in there system, but today it's back and working 

u_65N_10hpa_gefs.png

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Neath Valleys, South Wales 109m asl
  • Location: Neath Valleys, South Wales 109m asl
1 hour ago, BelgiumKiwi said:

After contacting her, she talked about a glitch in there system, but today it's back and working 

u_65N_10hpa_gefs.png

When I click on the picture I get a different chart as to when I'm viewing it Normal without expanding it. One shows the mean going for a SSW the other the mean bottoming out around 10m/s?? 

Edited by ALL ABOARD
Link to comment
Share on other sites

Posted
  • Location: Hertfordshire
  • Weather Preferences: SNOW AND FREEZING TEMPS
  • Location: Hertfordshire
4 minutes ago, ALL ABOARD said:

When I click on the picture I get a different chart as to when I'm viewing it Normal without expanding it. One shows the mean going for a SSW the other the mean bottoming out around 10m/s?? 

That’s last years graph when we had a ssw  , the updated one for now is only when you click on it and open it up .

Link to comment
Share on other sites

Posted
  • Location: Near King's Lynn 13.68m ASL
  • Weather Preferences: Hoar Frost, Snow, Misty Autumn mornings
  • Location: Near King's Lynn 13.68m ASL
8 minutes ago, ALL ABOARD said:

When I click on the picture I get a different chart as to when I'm viewing it Normal without expanding it. One shows the mean going for a SSW the other the mean bottoming out around 10m/s?? 

The original image is for 2018/2019 and is cached by Netweather. To show an updated image, you have to append a random query string to the URL as I've done here:

u_65N_10hpa_gefs.png?v=otbc

 

I added ?v=otbc but you can put anything, e.g. ?v=20191128105830.

Edit: The above is for 65N, and the below is 60N.

u_60N_10hpa_gefs.png?v=otbc

 

Edited by Yarmy
  • Like 2
Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-29 07:13:16 Valid: 29/03/2024 0600 - 30/03/2024 0600 THUNDERSTORM WATCH - FRI 29 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    Difficult travel conditions as the Easter break begins

    Low Nelson is throwing wind and rain at the UK before it impacts mainland Spain at Easter. Wild condtions in the English Channel, and more rain and lightning here on Thursday. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...