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Model output discussion 11th July onwards


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

ECM clusters on the 12z at T192 to T240:

66DFF666-D5FF-4DF3-A0FC-E7372E639548.thumb.png.8a698dedd3d77154893cbc66340b75d8.png

The first sees high pressure slip away from the UK, but it is hard to say the Atlantic breaks through at all.  The second is the continuity candidate.  These 2 are about equal, much less support for scenario 3 for an Atlantic ridge decomposing.  

All are compatible with the broad theme of a ridge somewhere close and no raging atlantic dominated patterns.  

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

I wonder if we might see more runs like this as we move through October, JMA 12z T264:

9E913C8E-1E7C-47D1-BDD3-5712F01FD038.thumb.gif.cda5b2da54d00e011f2416480caff9f3.gif

With highish heights over the pole, and the eventual moving of the current high pressure over the UK, but with nothing from the Atlantic, a north easterly is not a bad bet, could be a much colder last third of October for the north especially - and, importantly for later, cooling on the near continent.  

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

On the face of it, most of tonight’s ECMWF 12z ensemble mean looks benign under high pressure / strong ridging for the majority with winds becoming light, cloud amounts / sunshine variable and where skies clear, overnight fog patches forming and perhaps a touch of frost…I think only the far nw / n is the exception where Atlantic influence continues to brush around the top of the high…later there’s a swing towards unsettled from the NW but the s / se still looks decent in comparison?….I think it will become more widely unsettled during the last third of October as the GEFS 12z mean indicates and the pros too although again, the s / se could be drier and brighter more often than not.

C6933EBE-F506-4AE0-9D7E-97704BB913A0.thumb.gif.60f290dee6e1f968be39721354fca790.gif

Edited by jon snow
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Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl
36 minutes ago, Mike Poole said:

I wonder if we might see more runs like this as we move through October, JMA 12z T264:

9E913C8E-1E7C-47D1-BDD3-5712F01FD038.thumb.gif.cda5b2da54d00e011f2416480caff9f3.gif

With highish heights over the pole, and the eventual moving of the current high pressure over the UK, but with nothing from the Atlantic, a north easterly is not a bad bet, could be a much colder last third of October for the north especially - and, importantly for later, cooling on the near continent.  

Above chart a defintate direction of travel as we move into the last third of October.. high pulled west and we become exposed to polar air from between west and north.. deep scandi trough forming..

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Posted
  • Location: Woodchurch, Kent.
  • Weather Preferences: Storm, drizzle
  • Location: Woodchurch, Kent.

Chestnuts roasting on an open fire 

image.thumb.png.28b65f7649af70f580453ca184a73e6b.png

Best weather for Autumn in my opinion

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Posted
  • Location: Central Wales 250m (820ft) ASL
  • Weather Preferences: All
  • Location: Central Wales 250m (820ft) ASL

12z ECM op. The only retrogression of the UK high during the 10 day run is arguably between days 5 and 6. What we’re looking at the rest of the time is west to east travel, just all in extreme slow motion, the very slow periodic oscillation of the same trough-ridge-trough-ridge pattern for many weeks now. 

120h / 144h

E0FDAD3E-0B1A-4198-B061-9119084F82E9.thumb.png.623ef875f4833c9cb59b0a8f2f861d8d.png 0447B0A9-FEC5-4E78-8083-B4BEED57D914.thumb.png.163899dcaa6ee9a6a88dc9dd38c8368a.png


The low south of Greenland takes a week to reconnect with the Arctic trough without making any eastward progress during all that time, but the point is, it does reconnect, an eventual inevitability due to just hanging around for so long. 
168h

C1893F99-03D8-4230-A1AE-12D3CB005B73.thumb.png.9e2976bbee3485a7006f73e2fa8d02e7.png


Once re-engaged, the slow but sure momentum of the trough carries the low forward towards the UK and Ireland, so that over the following three days, it makes more steady progress east, eventually bringing us some less settled weather from the west.
240h

1B5DAF4A-1A3C-4ADD-95D2-33F31BF001B9.thumb.png.82484425037c3d2dd40be5eb452d367c.png

The trajectory is so slow and steady, you’d fancy the low to be in the Norwegian Sea by around day 12 and a northwesterly set in for a few days. 

With such slow movements and a docile Atlantic, by that point already troughing further west, and this new trough looking to merge with the one in front of it, there is good support from this evolution for below average temperatures and unsettled weather for the last 10 days of the month, growing colder particularly as the trough drifts east into Scandinavia.

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

Pub run getting going now and I’m struck by the distribution of weather over the NH, on our side nothing, on the other side all the fun and fair of the developing vortex, and a big foot print.  T168:

ACDB44BD-88A1-4E96-8CF7-BD481F068A25.thumb.jpeg.bffafb204b079ec07279c758050c65bf.jpeg

Edited by Mike Poole
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Posted
  • Location: Central Wales 250m (820ft) ASL
  • Weather Preferences: All
  • Location: Central Wales 250m (820ft) ASL

Yes me old chart pickers, here on the late shift, I’m pleased to play you the 18z GFS op and sing its praises for its broad consensus with the 12z ECM op - the two charts here for noon on the 19th. That’s good agreement for 10 days out.

GFS / ECM

57F6058B-8F8A-4A31-97AF-DCEDF319B6ED.thumb.png.f8dc1ac19f4d54d82f57c27a618bbc11.png 2F72AE68-E3A7-4D4B-B11E-B241B4751E47.thumb.png.1bf716c3796d3e4806e7dcda872aea37.png

 

And as we thought, two days later into a good northwesterly 

282h

BE3ED2DB-D5E2-4DAE-8024-9A97226ACDDB.thumb.png.67f1cc3872e1b2e0b865b3c749e4d019.png 


Some snow for the Scottish mountains at 300h

9A076682-0A6B-4FF9-983C-EF7674C56374.thumb.png.bc2875c03c71e0f46e57f9e639c107a6.png D74C61FB-A6C0-483C-8D37-1B42B4E74A86.thumb.png.236957d14bd9c03a64c10871ed2ed74c.png
 

And that groovy trough still strutting its stuff all the way through to the end of the run, here at 360h. Cool (or possibly even rather cold).

8115C6D8-0D78-4F31-AE08-7EC056ED21CA.thumb.png.90d708b83a906832bf1614755b10d3a2.png

3FB9B1C9-61BA-4BCD-8A3C-4BE3A1FC84DC.png

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

There’s an increasing number of benign members in the GEFS 0z longer term which is starting to have an effect on the mean, yesterday the mean became much more unsettled during the last third of October but now it doesn’t…having said that, there are still quite a few very unsettled members, and it should be noted that there’s some polar / arctic maritime shots as well as tropical maritime influence and the Gfs 0z operational does trend more unsettled during low res but perhaps we are seeing the models starting to backtrack on their very recent trend towards a very unsettled last 10 days or so of October?….perhaps the s / se in particular could be relatively benign not just during the week ahead, but the rest of the month too?

A725E6FF-F55B-4308-AD2C-04D42DE07BB2.thumb.png.a13c5cc233c1e18c86cf86d7eac2b68b.png

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Posted
  • Location: North East Cotswolds, 232m, 761feet ASL
  • Location: North East Cotswolds, 232m, 761feet ASL

Toggling between day 9 and 10 on the ECM makes you think a pretty chilly period would follow for the time of year .The latest GFS has somewhat moved away from that compared to yesterday but may return.

If the ECM is correct a few frosts and Scottish mountain snow showers could well be on the cards that final week of Oct!! 

83B46ED9-6862-4FE1-814C-4517A7F15577.png

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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.

Something may be afoot should the GFS 12Z be correct? That said, I've little faith in what NWPM's show at T+360! And, that said, the tPV will form; it's only a matter of where? and when??

h500slp.png    h850t850eu.png

h500slp.png    h850t850eu.png

h500slp.png    h850t850eu.png

 

Edited by Ed Stone
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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

Both the ECMWF 0z operational / ensemble mean indicate a mostly benign outlook with variable cloud / sunshine and overnight / early morning fog where skies clear…but then it starts to trend more unsettled from the NW with the SE last to see the change…but that’s 9 / 10 days away and for most of the u k with the exception of the far nw / n there’s a quiet / anticyclonic spell to come, not completely dry but pretty much until much later! ☀️⛅☁️ ?  

00264AFE-B470-445A-B41E-40B91F4D3C7A.thumb.gif.d3a752f1a669844b7b45cc4f258532b9.gifD29B4D89-1743-4B1C-A4F7-8292FBD2943B.thumb.gif.a39c518373fff446bd6a63ebf5906074.gif

Edited by jon snow
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Posted
  • Location: NR Worthing SE Coast
  • Location: NR Worthing SE Coast

Heading towards first cold blast of the season if gfs it to be believed.Soon is the time when snow can fall anywhere in the country .

Snow for the highlands on this run now.

 

Here we go again

Edited by SLEETY
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Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl
3 minutes ago, SLEETY said:

Heading towards first cold blast of the season if gfs it to be believed.Soon is the time when snow can fall anywhere in the country .

Snow for the highlands on this run now.

 

Here we go again

The direction to something colder comes courtesy of the ridge sinking south allowing a deepening Atlantic trough to swing down from the NW kicking the ridge out into the Atlantic. Takes a while to get there mild westerlies at first... the trough then digging into scandi..

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Posted
  • Location: Welwyn Garden City
  • Weather Preferences: Seasonal and interesting weather including summer storms and winter snow
  • Location: Welwyn Garden City

First potential autumnal clash of the air masses shown on gfs 6z at 240. Many variations on this no doubt in the coming days...should reawaken interest...

image.thumb.png.094cf29a7ecf8da50894a11834bab7b1.png

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Posted
  • Location: Hoyland,barnsley,south yorkshire(134m asl)
  • Weather Preferences: severe storms,snow wind and ice
  • Location: Hoyland,barnsley,south yorkshire(134m asl)

The gfs 12z going for this at day ten with -8's into Scotland and -6's into N England,...BRRRR!!!,snow snaw for the Scottish hills no doubt with maybe some wintriness in the showers further south. 

gfs-1-240.thumb.png.5e2c1f31413a8b1d8e6ad92dacb54534.png

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Posted
  • Location: East Ham, London
  • Location: East Ham, London

Fair to say benign continues on the 12Z GFS OP - Control is rather more interesting if you fancy something colder from the north.

GEM goes strongly unsettled - a return of Greenland heights by T+240.

Plenty of options as you would expect - I wouldn't rule out a brief colder incursion which wouldn't be unusual and some early snow for the Scottish mountains.

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

P14 is a cracker, just waiting for Exeter to jump on-board the polar express now?!  …. If I had a wishbone  ❄️ 

DE86A589-E495-49ED-B6FF-BAF076A03E8A.thumb.png.8864df02c9a360c03b126ab08d75de44.pngF2F2845D-3799-4D24-98DB-FDA3C010558C.thumb.png.937c2d83f3aca1c4eb8ce6afdb0443e3.png8EF80DC1-B767-48FF-A4B3-FB00B84F4268.thumb.png.0d6e0de09d7c8703c4fd384f6f5b581e.png1528AC21-8BB6-46C4-8568-EBB28ACD0079.thumb.jpeg.945d378cb28c8291aafa15453b12e5af.jpeg

  

Edited by jon snow
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Posted
  • Location: Woodchurch, Kent.
  • Weather Preferences: Storm, drizzle
  • Location: Woodchurch, Kent.

Here are my predictions based on the 0z and 6z models

12th October 14:00

0z

image.thumb.png.c5db51ac8237da09675287bcc249ca4d.png

6z

image.thumb.png.c9692310d37c7b3773f7bdf8e53d35e9.png

Suspected Ouctcome

Agreement : 95%

Outcome : 85-89% 

Often it's a slightly eastward movement

Often weaker high's

13th October 14:00

0z

image.thumb.png.05c83fe1b1210161c8271f99fa9f42fc.png

6z

image.thumb.png.9130bb4cea041a31501cdc2067cfa1a6.png

Suspected Ouctcome

Model agreement : 90%

Outcome : 80-84%

Eastwards shift and downgrading the high

14th October 14:00

0z

image.thumb.png.306c0c94803bdd433b73e11069fe3589.png

6z

image.thumb.png.6995cc2b7208504106530e18c3d1372f.png

Suspected Ouctcome

Model agreement : 80%

Outcome : 70-74%

Change in high falling to the south and east and weakening allowing low to push closer to Scotland

15 October 14:00

0z

image.thumb.png.9c3cedfc37549ee2dcc62ccffccc703b.png

6z

image.thumb.png.9f715cd4b75ddecbbfec79d3ad7c8b47.png

Suspected Ouctcome

Model agreement : 75%

Outcome : 65-69%

Assuming the before mentioned happens then the low would continue to strengthen again pushing up against this high which continues further south

16 October 14:00

0z

image.thumb.png.5f09235be66b2973e98bda0e80546e61.png

6z

image.thumb.png.54d48f43e74caff4e0142f1b2d2541b7.png

Suspected Ouctcome

Model agreement : 55%

Outcome : 45-49%

Continuing with the changes that I suspect will happen, we see the low rolling into Scotland with the low toppling south east again

17 October 14:00

0z

image.thumb.png.ce9474f228f028aeb56275e07cc7aeab.png

6z

image.thumb.png.19695a6409d19a3fdb2e10d92202d375.png

Suspected Ouctcome

Model agreement : 52%

Outcome : 42-46%

Outcome will continue south with the high sliding further south east

18 October 14:00

0z

image.thumb.png.b916f6b550c0457d59430a6d59aa461a.png

6z

image.thumb.png.32b106782118f270597e158b6c2fe33e.png

Suspected Ouctcome

Model agreement : 45%

Outcome : 35-39%

Low slides south east around half and half in the United Kingdom between low and high

Conclusion

I'm not a proffesional forecaster by any stretch of the imagination but having used the model agreements to Outcome's from before here is the conclusion of it all together in one paragraph. Often it's a slightly eastward movement, often weaker high's. Before an Eastwards shift and downgrading the high, change in high falling to the south and east and weakening allowing low to push closer to Scotland. Assuming the before mentioned happens then the low would continue to strengthen again pushing up against this high which continues further south. Continuing with the changes that I suspect will happen, we see the low rolling into Scotland with the low toppling south east again. Outcome will continue south with the high sliding further south east.Low slides south east around half and half in the United Kingdom between low and high.

Here's the updated 12z

image.thumb.png.8b8d6b40cf3eb7a0de7b7d2069e9d2ba.pngimage.thumb.png.81b850a9702eeb2fe4102e7729013de6.png

image.thumb.png.e077363c0a5801803561f7b1902258c2.pngimage.thumb.png.44d15370fec2475698f152784502afdb.png

image.thumb.png.9c715698e686e099dee7a30b9effd990.pngimage.thumb.png.e8ff9ee99162f6044ffb7297b63e865f.png

To be fair I think I was pretty close just going a bit too fast but I did do it 2 days at a time when looking at model agreement.

Xander

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