Model Output Discussion Autumn 2024

[HarvSlugger]

I just wanted to mention this(I'm posting it here because more people will see it,sorry)

Where I live in Pembrokeshire we have something called the preseli hills,which never ever get mentioned unless it's Derek Brockway,but the preseli hills are a very small area compared to Dartmoor and Exmoor,but we have a mountain here that is actually higher than the whole of Exmoor, sad that met office has never ever mentioned preseli hills,I wonder if they even know they exist I recommend you all Google them,it's the place everyone goes in Pembrokeshire to see snow,and gets copious amounts of rain and wind!

Off topic I know, but if you like beautiful scenery and history here you go:)

 

 

Edited November 12, 2024 by HarvSlugger

[Jacob]

 HarvSlugger Not completely sure, unless we get upgrades, the south could still be too mild unless there’s precipitation at nighttime or early morning with these uppers 

[Dennis]

KMA after 20th

 

[Mcconnor8]

 Jacob For the South it depends more on getting the perfect placement of a slider, you can get heavy snow under just -2/-3 uppers with a slider as the GFS 0z shows on Day 9 or the KMA charts I posted earlier

[Dennis]

there could be seen a dangerous (snow) storm to south UK 

[bluearmy]

 Nick2373
Agree 100% re coasts - one of the consequences of the sst chart I posted yesterday 

Generally in the U.K. one of our holy grail scenarios is a sustained slack cold trough because it minimises the influences of sst.   The ec op delivers that this morning. 
 

is it likely to be right ?  Probably not, looking across the output. But the fact that the op finds it as a solution means it not discountable. 
 

ens suites are all showing the Atlantic pushing into the nw euro trough as week 2 progresses. That should mean a snow event somewhere across the U.K. is a probability rather than a possibility. that’s notable for November. 

 

[bluearmy]

Uppers not as relevant under a cold slack trough  Jacob at this time of year with low solar input.  Check the thicknesses and most importantly dp’s because the models will be best at resolving those. 

Edited November 12, 2024 by bluearmy

[PompeyFC]

 Nick2373

 

The old adage on here, get the cold in, then we can worry about where might get snow 

[Mcconnor8]

Slider alert on the ECM AI run, this would give an absolute dumping to the Midlands in less than a weeks time...

Looking alright at Day 10 as well, the cold hangs on for quite a while 

Edited November 12, 2024 by Mcconnor8

[bluearmy]

 Mcconnor8 and again a week later ….

[carinthian]

Morning all. Well 24 hours on and all models trending towards cold from next Sunday. Regarding any snowfall next week shown in the medium term results has at this stage not to be taken as Gospel. As mentioned earlier forecasters will look for some consensus in the main models at 120t and it will not be at until 96t that the fine mesh snow models start producing the predictive values with some degree of accuracy. We over here in Central Europe have a powerful one that can provide outer perimeter results for the British Isles but first results will not be available until Friday at the earliest. This mornings GFS/ GEM and extended UKMO starting to show some disturbance from the SW to hit the cold air in place over The British Isles early next week. Lets see if this trend continues .

Have a nice Autumnal to all in blighty.

 C

[CoventryWeather]

Good runs this morning, the shortwaves still uncertain but likely they'll correct south as we head further towards next week. 

Slightly concerned about the GFS deep low but as normally expected at that time frame it's likely overdoing it, but something to keep an eye out for. Suitable conditions for fairly rapid deepening. 

[tight isobar]

 Mcconnor8 also evedent on the gfs 00z- although toning in slightly milder air into the mix.as slightly further north-But certainly 1-2 watch .. as we gain !

Edited November 12, 2024 by tight isobar

[Mike Poole]

Good runs this morning, I think over the last few days the pattern has morphed from a direct northerly, to a northerly that misses west, to a cold blast which struggles to get far enough south, to a rather broader trough which does get far enough south.  Looking at the ECM clusters, this trough in the T192-T240 timeframe gets as far as Spain in clusters 1 and (in particular) 2:

I think this gives additional margin for error, in that the push of cold air is broader.  Cluster 3 less promising as it pushes up against the Azores high, which is not present on the other two clusters.  

Edited November 12, 2024 by Mike Poole

[CoventryWeather]

That looks interesting, especially cluster 5 with the Scandi Ridge. 

[Mike Poole]

 CoventryWeather Indeed, dangles the possibility of a more sustained cold pattern evolving, with heights moving around to our north.

[Chesil View]

Without taking any of the slider detail too seriously. (Because you can't at this range). There does seem to have been a cross model move towards colder outcomes this morning.  Still some time for this to be maintained and get those various sliders and channel runners down to T48 when we might be able to give them some credence.

Going in the right direction is the best that can be said for now.

Edited November 12, 2024 by Chesil View

[Lukesluckybunch]

Icon looking great at 120,a slight shift east again I think

[Mcconnor8]

 Lukesluckybunch

Yes more of a direct Northerly than the 0z run so colder uppers arrive quicker, hard to extrapolate beyond that but looks good.

[Battleground Snow]

 Mike Poole

I still think there is enough time to get a direct northernly from the initial plunge on the 17th, if that Atlantic ridge edges east over the coming runs.

The colder we are initially, the less chance any shortwaves or lows turn to rain over the south

[johnholmes]

An interesting comparison

Charts for next Monday from the extended UK Met computer output and the GFS 00z output for the same day/time.

For what it is worth, this far out, they are relatively similar. GFS has the deep surface low but the main trough is similar on both along with the upper high position and main surface ideas.

 

weather-met and gfs mon18 nov 2024.doc

Edited November 12, 2024 by johnholmes
spelling

[northwestsnow]

Well they have " snow dogs " in Buxton this winter  @Georgina and I'm willing  to bet the snow dogs will be feeling very at home next week

Let's keep a keen eye on Exeters musings today ,after viewing the EC 00 clusters the cold is surely coming and with the Peaks 300- 400m.....

Edited November 12, 2024 by northwestsnow

[HarvSlugger]

Who's excited for the met office deep dive?

Edited November 12, 2024 by HarvSlugger

[Frosty.]

It’s no exaggeration to suggest some areas of the u k could see disruptive snow next week, the Gfs 0z op for example!..anyway,..at this range it’s more about the general trend, and that suggests / implies a colder and very unsettled period beyond the current benign / anticyclonic spell this week!  

[bluearmy]

 HarvSlugger experience tells us that they’ll be very conservative because anything else will lead to express style headlines across the media (plus the output doesn’t convincingly support widespread lowland snowfall atm)