Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Model output discussion - 7th January onwards


Paul
Message added by Paul

Please keep this thread solely to discussing the model output. The model banter thread is available for more loosely model related chat, ramps and moans.

Recommended Posts

Posted
  • Location: Lee, London. SE12, 41 mts. 134.5 ft asl.
  • Weather Preferences: Cold, Snowy Weather
  • Location: Lee, London. SE12, 41 mts. 134.5 ft asl.
10 minutes ago, Seasonality said:

Interesting to see where this run falls. What I note is just how damn annoying it is for UK cold weather fans. So often it's the UK stuck in its own little mild sector compared to Europe at that latitude and sometimes even the neighbouring Atlantic. 

anim_grp6.gif

With that huge body of water directly to our west and with our prevailing S.W. flow, 'twas ever the case. It seems to be increasingly difficult to experience a cold, wintry spell in the mid Winter month of January!! And with bitter cold flowing out of Canada and the N.E.States, firing up the Jet Stream, we may have to wait until February, to get a decent shout at a cold, wintry spell. Hopefully, the Atlantic would've "calmed down", by then.

Regards,

Tom. :hi:

Link to comment
Share on other sites

Posted
  • Location: Frankley, Birmingham 250masl
  • Weather Preferences: the weather extremes in general but my favourites are snow & thunderstorms
  • Location: Frankley, Birmingham 250masl

ITS FI FOR A REASON! Did people really expect to come on here this morning to be greeted by the same charts as last night? Really, there will be upgrades and downgrades in every run between now and next week, don’t worry about it let’s get the cold here first before all the panic about a possible easterly 

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

Hoping the GFS suite is a rogue run. However, it does indicate that with the Pacific Ridge and the seemingly slow breakdown of the PV and its unhealthy placement for the UK, any Atlantic rises could struggle:

gensnh-21-1-216.thumb.png.7b6f0d3964c4539151dda1c0a4be2e44.png1464985612_gensnh-21-1-384(3).thumb.png.d1af43ce67843d11e95c83f9dc81ae1d.png

The mean at T9 and T16 show a strong Canadian PV lobe, combined with the Pacific Ridge, a westerly flow with a subdued Atlantic High would lead to a PM flow. A possibility? The caveat is when GFS spots a new trend it overreacts especially if it is the Atlantic, so the 0z suite may be the worst-case scenario!

There is little more to say about the ECM propensity to overblow heights in FI. It is rarely right, though I was hopeful, and remain so, though may be delayed, due to the ongoing downwelling. However, the outcome of the SSW may be difficult to predict, maybe the models jumped the gun, certainly, the GEFS are backtracking viz blocking in FI?

These are just musings and it could all flip to better in the next day or so. Entropy remains the watchword and the good news is if this is a slow burner we have plenty of time on the clock to get back on track.

Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans
2 minutes ago, nick sussex said:

Nick F has explained the importance of the US storm so I won’t go into too much detail but that in a nutshell is the key thing to look at.

The only good news this morning is that the UKMO has developed that more than last night where it had a weakening storm which became a shallow wave off the eastern USA.

These types of storm cause problems because the interaction between southern and northern stream jets often causes model problems .

 

More than a few hints out there that we could see this push ne of heights by day 8 establishing a scandi ridge or wedge in the 9/12 day period ........ with the jet still likely to be active, that brings the potential for a week two slider back into play, especially if we retain some low heights over Europe ......

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Raynes Park, London SW20
  • Location: Raynes Park, London SW20

Early viewing of the EPS in the day 6-8 range suggest that more amplified solutions are still in the mix.  Plenty to keep us interested.

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Guest Delete Me

Is the reason for the poorer performance of the 06z the downturn in aircraft data at night being fed into the model?

I know the GFS uses data from aircraft to feed its models but wondered if ECm did the same?

Link to comment
Share on other sites

Posted
  • Location: Reading/New York/Chicago
  • Location: Reading/New York/Chicago
4 minutes ago, nick sussex said:

Nick F has explained the importance of the US storm so I won’t go into too much detail but that in a nutshell is the key thing to look at.

The only good news this morning is that the UKMO has developed that more than last night where it had a weakening storm which became a shallow wave off the eastern USA.

These types of storm cause problems because the interaction between southern and northern stream jets often causes model problems .

 

Yep. And I hate to say it as it's a tired cliche, but we have more than one bite of the cherry. Experience of living in New York also tells me that these storms tend not to be forecast accurately until quite close to the time. There were a number of occasions where a forecast Nor'easter would switch to a rainmaker as it tracked further inland than originally forecast. These things are a little like hurricanes in that respect; there is a cone of uncertainty which slowly narrows as it comes closer to the forecast period. 

Until the energy which powers the storm enters the southern conus, after which it tracks up the east coast meeting with energy from further north, it is not usually possible to get an accurate prediction.

ECM does not show high building over UK at the end; further disruption looks likely.

  • Like 3
  • Thanks 3
Link to comment
Share on other sites

Posted
  • Location: Gillingham, Kent
  • Weather Preferences: Snow, Thunderstorms,
  • Location: Gillingham, Kent
2 hours ago, CreweCold said:

Matters not one jot if the EC turns out to be wrong. 

Not sure what your issue is, I've not dismissed cold and/or snow chances anywhere... And I've repeatedly said that I expect a Scandi high month's end. 

 

2 hours ago, CreweCold said:

He owns a weather website (I think) you'd think (hope) he would already know that. 

I was simply pointing out that the EC wasn’t supportive of the GFS either since you keep banging on about the GFS not supporting the EC. 

FYI the EC Det was a cold outlier last night, so not entirely surprising to see it swing the other way this morning. None of the models know whats happening, they’re all pretty useless beyond 144hrs at the moment. 

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

Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .
3 minutes ago, bluearmy said:

More than a few hints out there that we could see this push ne of heights by day 8 establishing a scandi ridge or wedge in the 9/12 day period ........ with the jet still likely to be active, that brings the potential for a week two slider back into play, especially if we retain some low heights over Europe ......

I think day 8 seems a long way away ! The knock on effect of what the upstream low does by day 6 does impact the future evolution .

The ECM just about scrapes enough trough disruption but it’s a close run thing . Once we know the ne USA low solution we’ll have a better idea of where things might go .

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Heckmondwike, West Yorkshire
  • Location: Heckmondwike, West Yorkshire

A lesson I have learnt over the years is that if the ecm op is the only model showing a high degree of amplification to our north west, only trust this if it ticks down to the 4 day mark. 

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Posted
  • Location: HILL OF TARA IRELAND
  • Weather Preferences: SNOW ICE
  • Location: HILL OF TARA IRELAND
3 minutes ago, nick sussex said:

I think day 8 seems a long way away ! The knock on effect of what the upstream low does by day 6 does impact the future evolution .

The ECM just about scrapes enough trough disruption but it’s a close run thing . Once we know the ne USA low solution we’ll have a better idea of where things might go .

 What run do you think will confirm this Nick12z.

Edited by snowice
Link to comment
Share on other sites

Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .
3 minutes ago, WhiteFox said:

Yep. And I hate to say it as it's a tired cliche, but we have more than one bite of the cherry. Experience of living in New York also tells me that these storms tend not to be forecast accurately until quite close to the time. There were a number of occasions where a forecast Nor'easter would switch to a rainmaker as it tracked further inland than originally forecast. These things are a little like hurricanes in that respect; there is a cone of uncertainty which slowly narrows as it comes closer to the forecast period. 

Until the energy which powers the storm enters the southern conus, after which it tracks up the east coast meeting with energy from further north, it is not usually possible to get an accurate prediction.

ECM does not show high building over UK at the end; further disruption looks likely.

Great post WF.

Yes these types of storms are difficult to pin down .  We need the earliest possible phasing of north and southern jets , that will blow the storm up and take if further inland .

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: NR Worthing SE Coast
  • Location: NR Worthing SE Coast

One thing I have learned is never trust anything in fl at 168 hours plus until it gets down to at least 96 hours, whatever it shows.So currently no model has :won, as it hasn't happened yet

  • Like 8
  • Thanks 1
Link to comment
Share on other sites

Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .
7 minutes ago, snowice said:

 What run do you think will confirm this Nick12z.

I think tonights outputs .

The trend this morning has been to have a less amplified storm , apart from the UKMO which yesterday night looked very dubious .

Tonight we’ll see if that trend continues or whether we can see a trend back to the deeper more ne tracking low .

To add to the drama NCEP mentioned that there’s an issue with where the southern stream shortwave  originates in the Pacific and there’s a lack of balloon data until it gets closer to the west coast  , and they’re currently mainly using satellite data . 

This shortwave then phases with the northern jet but where exactly is key .

Edited by nick sussex
  • Like 3
  • Thanks 2
Link to comment
Share on other sites

Posted
  • Location: Camborne
  • Location: Camborne
54 minutes ago, Nick F said:

As I mentioned last night, the winter storm tracking out of US Plains then up across the eastern seaboard of N America towards Greenland could play a crucial role in how the low moving over Iceland ahead of it behaves, the low we want to drop SE towards UK and mainland Europe to trigger a decent easterly.

The winter storm on GFS pushes northeast too far east into Greenland and thus flattens the ridge too much downstream over the north Atlantic to allow the low over Iceland to move SE over the UK, instead it carries on east to the north of the UK.

GFSOPEU00_156_1.thumb.png.df5f36a0774d8e2fcb99bee1053d6128.png

The storm on 00z EC heads to Greenland weaker but still flattens the flow more than yesterday's 12z, so although the low still drops SE towards UK, but too shallow to have a trigger effect to bring a decent easterly.

Perhaps we threw caution to the wind too much after the euphoria following yesterday's evening runs, lots of pieces of the jigsaw need to fall into place for the UK to get a decent easterly to develop on the back of the amplification over the Atlantic next week. Hopefully it's the usual downbeat 00z runs of recent days followed by better 06z/12z/18z runs!

Is to some extent the movement of the intense upper trough in eastern North America a pretty key ingredient? It initiates the amplification of the Bermuda high pressure and it's the direction and strength of the thermal gradient that follows that determines the strength of the ridging which in turn will control the move of surface lows

t144.thumb.png.6d8cafe13ce588676ebd1467095dcb39.pngt198.thumb.png.4bd5278c071700952558720a2b57c243.png

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: HILL OF TARA IRELAND
  • Weather Preferences: SNOW ICE
  • Location: HILL OF TARA IRELAND
6 minutes ago, nick sussex said:

I think tonights outputs .

The trend this morning has been to have a less amplified storm , apart from the UKMO which yesterday night looked very dubious .

Tonight we’ll see if that trend continues or whether we can see a trend back to the deeper more ne tracking low .

You would imagine with all that  cold water the Lp would intensify !we will just have to wait till the 12z.

 

Edited by snowice
Link to comment
Share on other sites

Posted
  • Location: Warsaw, Poland. Formerly London.
  • Weather Preferences: Four true seasons. Hot summers and cold winters.
  • Location: Warsaw, Poland. Formerly London.
37 minutes ago, TomSE12 said:

With that huge body of water directly to our west and with our prevailing S.W. flow, 'twas ever the case. It seems to be increasingly difficult to experience a cold, wintry spell in the mid Winter month of January!! And with bitter cold flowing out of Canada and the N.E.States, firing up the Jet Stream, we may have to wait until February, to get a decent shout at a cold, wintry spell. Hopefully, the Atlantic would've "calmed down", by then.

Regards,

Tom. 

I know Tom. Geography is a real *****.

  • Like 2
Link to comment
Share on other sites

1 minute ago, edinburgh_1992 said:

Hardly looks wintry to me, with quite a few members going above average at times. We need at least -5 for snow at low levels, and that will be a struggle even up north

gefsens850Edinburgh0.png

No you don't, you could have uppers of 0c and have snow if you have a cold layer being dragged under from the continent. Very rare, but does happen... Ive even seen snow fall at +3 degrees air temp... 

A lot of the issue here and no disrespect to anyone learning or wants to learn. Some people don't understand how some charts look and what they actually represent on the ground that more knowledgeable people will. 

Bit of a catch 22 having access to data that's not normally in the public eye... 

For now I'm letting the GFS still do its own thing... Its one run and is yet to be fully supported.

 

Watch this space 

  • Like 2
Link to comment
Share on other sites

I think that this is a blip, however i think that a deep cold spell can be taken off the table, but it will certainly stay cold. However the last thing we want is for high pressure to return for europe which is looking increasingly likely... 

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Lytchett Matravers - 301 ft ASL
  • Weather Preferences: Snowy Winters, Torrential Storm Summers
  • Location: Lytchett Matravers - 301 ft ASL

Ahh the good old knee jerk reaction to on a single run.. sigh  

if these have flipped overnight

E32D55A2-12DD-4F72-94DB-553EE32A37DD.thumb.gif.fbb5d7526532c6ae8e6d722e3bad795b.gif

I will be more than a little surprised!!

  • Like 7
  • Thanks 1
Link to comment
Share on other sites

Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .
10 minutes ago, snowice said:

You would imagine with all that  cold water the storm would intensify !we will just have to wait till the 12z.

 

The intensification this time is moisture pulled in from the Gulf of Mexico . This then meets Arctic air  as the Canadian high amplifies and pushes south .

In these cases what the storm does directly correlates with the jet track into Western Europe , the more amplified upstream will amplify the displaced Azores high , it will also drain some of the energy from the low to the nw at day 6 as the PV lobe becomes detached from it , this will then help to disrupt that so instead of a barreling low moving se you end up with some shallower shortwave energy .

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

Posted
  • Location: King’s Lynn, Norfolk.
  • Weather Preferences: Hot and Thundery, Cold and Snowy
  • Location: King’s Lynn, Norfolk.
Just now, nick sussex said:

The intensification this time is moisture pulled in from the Gulf of Mexico . This then meets Arctic air  as the Canadian high amplifies and pushes south .

In these cases what the storm does directly correlates with the jet track into Western Europe , the more amplified upstream will amplify the displaced Azores high , it will also drain some of the energy from the low to the nw at day 6 , this will then help to disrupt that so instead of a barreling low moving se you end up with some shallower shortwave energy .

Some possible tornadoes then as well as snow coming in on the wrap around behind the storm. Ah the US always gets the real fun stuff! 

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Broxbourne, Herts
  • Weather Preferences: Snow snow and snow
  • Location: Broxbourne, Herts
38 minutes ago, TomSE12 said:

With that huge body of water directly to our west and with our prevailing S.W. flow, 'twas ever the case. It seems to be increasingly difficult to experience a cold, wintry spell in the mid Winter month of January!! And with bitter cold flowing out of Canada and the N.E.States, firing up the Jet Stream, we may have to wait until February, to get a decent shout at a cold, wintry spell. Hopefully, the Atlantic would've "calmed down", by then.

Regards,

Tom. :hi:

I don't doubt that you are right. I just wonder how it is that, despite what you say,  the models in their latter stages seem to find so many solutions that provide us with decent wintry spells in their outlooks, that then fail to materialise to anything like the degree they've been showing us.

Is it time to build a factor into our interpretations of what the models show beyond a certain time that allows for a bias in providing the UK with wintry options?

  • Like 1
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...