Atlantic Storms Winter 2015/16

[Cookie]

Seems to be not as strong but over longer time frame 

[Liam J]

Still on course for some extremely windy weather across the north into Friday morning, BBC said 80-90mph in the far north of Scotland and 60-70mph further south so not sure what you meant by the whoopsee @The PIT ? GFS predicting 90-100mph on the 00z, looks bad enough @cookie 

Another very windy spell Monday into Tuesday. 

Edited January 28, 2016 by *Sub*Zero*

[NO LONGER POSTING]

South will not even know what is going on!

[Zenarcher]

GFS 06z stays the same for the track of the storm and how strong the winds will be. It reminds me of the 3rd of February 2011 storm it took the exact same path with similar wind speeds.

 

  

[weather09]

Does look an active period coming up for northern UK this weekend.  Stormy winds tomorrow, then quite a deep cold pool moving in at 500mb through Sat post-CF (sub -40C per GFS), more far N Scotland, with notably steep mid-levels as a result, suggesting prolific lightning activity with snow showers packing in.  

Edited January 28, 2016 by weather09

[Liam J]

Yellow and amber wind warnings now in force for tomorrow, would have expected the amber to include all of N Scotland and the N Isles given some of the predicted gust speeds up there. The strongest winds are mentioned in the yellow warning with 90mph possible far N of Scotland & the Isles. Rough period of weather... Even south of the border gusts of 70-80mph possible inland according the warning as the cold front moves through, nasty.

Edit - N Isles now have an amber warning, gusts up to 90mph possible. 

Quote

Be prepared for dangerous conditions including structural damage and debris, disruption to power supplies and widespread disruption to transport.

Warning map looks busy!

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=map&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1453939200

Edited January 28, 2016 by *Sub*Zero*

[Liam J]

Wind warning been issued for Monday, 60-70mph gusts widely with 80mph possible.

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=map&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1453939200

 

[Weather26]

That will be storm Henry getting named over the weekend then.

[knocker]

Can't post the chart twelve hours later but it shows surface gusts in excess of 80kts for NW Scotland 00z Tuesday.

[Sainsbo]

ARPEGE has gone a little crazy on the 12z, has a very small but extremely severe low passing over the north of Scotland tomorrow night.

 

Very tightly packed isobars. Not sure how much confidence people put in the ARPEGE, but showing gusts of 180km h^-1 over scotland - That translates to 110mph. 125mph off the west coast.

 

 

Luckily no support from the NMM or GFS for anything like this, just thought it was interesting as I can't remember ever seeing 200kmh^-1 being predicted by any model for somewhere near the UK

 

Edit: The HIRLAM 12z shows a similar feature, albeit a bit weaker.

Edited January 28, 2016 by Sainsbo

[tinybill]

reg  the wind   this from  iceland  met

[Nouska]

3 hours ago, Sainsbo said:

ARPEGE has gone a little crazy on the 12z, has a very small but extremely severe low passing over the north of Scotland tomorrow night.

That feature is still on the 18Z update - I wonder if, being a mesoscale model, it is trying to develop a polar low of some sort. The model has 500mb temps as just about cold enough for development.

     

[Sainsbo]

27 minutes ago, Nouska said:

That feature is still on the 18Z update - I wonder if, being a mesoscale model, it is trying to develop a polar low of some sort. The model has 500mb temps as just about cold enough for development.

     

I think you may be right, though I didn't realise just how small they could be!

 

Either way, those are some seriously strong projected wind speeds.

NMM still doesn't create the feature, despite having mid level tropospheric temperatures 5 degrees or so colder, and the 18Z HIRLAM shows it, but much less severe. I guess we'll have to wait and see.

Edited January 29, 2016 by Sainsbo

[Fiona Robertson]

4 hours ago, Nouska said:

That feature is still on the 18Z update - I wonder if, being a mesoscale model, it is trying to develop a polar low of some sort. The model has 500mb temps as just about cold enough for development.

     

Can you explain this "polar low" for me, please? What are the ramifications if it is?

[Nouska]

5 hours ago, Fiona Robertson said:

Can you explain this "polar low" for me, please? What are the ramifications if it is?

For the meantime there are no ramifications as it is just a suggestion from a model that is designed to be highly sensitive to convective development - it will be interesting to watch satellite later and see if it is correct in doing so.

If it did develop, outcome would likely be blizzard conditions for the area that it crossed.

@johnholmes has written a splendid post on polar low development - easy to read and understand.

 

 

 

[Fiona Robertson]

11 minutes ago, Nouska said:

For the meantime there are no ramifications as it is just a suggestion from a model that is designed to be highly sensitive to convective development - it will be interesting to watch satellite later and see if it is correct in doing so.

If it did develop, outcome would likely be blizzard conditions for the area that it crossed.

@johnholmes has written a splendid post on polar low development - easy to read and understand.

 

 

 

Thank you very much for that, it really helped.

[cowdog]

Really don't look at Monday's storm. Never thought it was possible, but the ARPEGE is showing almost 200kph gusts over the Western Isles of Scotland, with widely 150 kph over Western Scotland. That needs a significant downgrade fast. Its showing 100+ kph for the Northern Pennines as well, its really a frightening storm as shown at the moment, really have got to start hoping for massive downgrades on it or else there will be significant loss.

[Liam J]

Amber warning now for Scotland tomorrow for snow & wind, sounds interesting, blizzards, drifting, Ice accretion, hail & lightening strikes! 

Quote

In addition, gusts of 50-60 mph are likely at times, occasionally 70 mph across the far north and west of the amber area and over mountains. This will lead to blizzard conditions at times and drifting of snow. Power supplies may be disrupted by ice accretion and also by lightning strikes, with hail also likely.

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=warnings&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1454112000&regionName=dg

[weather09]

Interesting discussion re. PL. Still showing on 00z. Hadn't looked at Arpege model previously, though global models/Euro4 have been modeling a small region of deep cold air at 500mb passing far N Scotland this evening, with mid-level lapse rates exceeding 9C/km.  Large scale ascent with deep trough and diffluent jet aloft favours deep convection with hail, squally downdrafts and lightning all risks.  

Interesting period.  

Edited January 29, 2016 by weather09

[Nouska]

High-res satellite animation shows a little comma like feature in the flow but, in keeping with latest model output, does not develop.

http://brunnur.vedur.is/myndir/seviri/2016/01/29/seviri_nat_ir3-9.html

Keyra button for animation.

 

[Liam J]

Local BBC weather presenter just mentioned that we could have the 8th named storm of the winter on Monday, storm Henry. 

 

Similar gust strengths on the GFS 12z to Gertrude but the stronger winds further south.

UKMO 10m wind charts only go out to 72hrs but you can see 10m wind speeds of 90-95km/h west of Ireland by 12z Monday.

[Abyss]

@*Sub*Zero* What's your feeling on Mondays storm. Do you think it will track further North or South?

[cowdog]

15 minutes ago, *Sub*Zero* said:

Local BBC weather presenter just mentioned that we could have the 8th named storm of the winter on Monday, storm Henry. 

 

Similar gust strengths on the GFS 12z to Gertrude but the stronger winds further south.

UKMO 10m wind charts only go out to 72hrs but you can see 10m wind speeds of 90-95km/h west of Ireland by 12z Monday.

Note the ARPEGE has toned it down significantly from the 0z and 6z runs, and also shifted it 50-100 miles north. Now really almost a repeat of Gertrude, thankfully as what it was showing would have been historic.

[Liam J]

Just now, -Bomber- said:

@*Sub*Zero* What's your feeling on Mondays storm. Do you think it will track further North or South?

On current output Scotland looks like i'll get hammered yet again but the core of damaging winds look further south and will be affecting more of the mainland, still some time for changes with 3 days to go so may go a bit further north or a bit further south. Very windy for much of northern UK, will have to see how the models handle it over the weekend. Very likely Henry will get named. 

[Liam J]

The 12z JMA looking pretty severe for Monday, severe gale to storm force winds for northern UK & Ireland.