Model Output Discussion - Into 2024

[carinthian]

On 07/01/2024 at 07:11, carinthian said:

Morning all from a snowy Salzburgerland , temp now dropping over here after a week or two of mildish weather . For some sort of consistency I have attached the 168t chart from UKMO . Um boys and girls make your forecast based at that chart ? Think inevitably there is going to be a clash or air masses, but where will this zone end up ? How far can the Arctic Front get south or will it be retarded coming up against the rise in pressure over France ? or will there be a middle ground ? Of course it could end up a clean cut sweep from cold to mild or cold wins out ! Fascinatingly , interesting winter charts to unfold. Its going to be a ride this week but for you lot back in blighty enjoy the colder drier spell for much of this working week , Still to far out to see what evolves by next weekend. Meanwhile the establishment of The Italian Low to produce some much need fresh snow to most of the Alps. To prolong any cold spell we all need its circulation to stay in put for much longer than some of the models show this morning. Enjoy your weekend and some may see a flurry or two.

C

Morning all. A bit of an update from my last post above sent on Sunday. Are we any the wiser for next weeks developments ? Meanwhile, we have an important World Cup Giant Slalom race on the local mountain in a couple of days. Cold snowy conditions look to remain before quietly warming up next weekend, So thats good timing. Back to the models and UK prospects. So again for some consistency, the UKMO extended still shows potential battleground but again with no clear cut route to depth in cold.  This mornings other models, especially ICON advance the colder air more quickly during Saturday night, that would be the best result to get the colder air in place earlier. The feeling over here from the experts is for that to take place as there is an expectation that the push from the Arctic will be strong enough to advance the front more quickly during this weekend. This should soon show in  outputs over the next couple of days and could again change the snow potential forecasts. Just as a bit of information showing on the snow model they use , has an up tick in snow for NW England by this time next week. Read what you want to in that .Happy model viewing, hope its not sending you crazy !

C

Edited January 10 by carinthian

[Ali1977]

Get in, loving the upgrades overnight another day of chasing ahead ️

[Chesil View]

My take this morning based purely on det runs. Gfs has moved somewhat towards ecm /ukmo in medium term. Gem best of the bunch so far for preserving longevity of cold spell.

We await ecm but again with the caveat that none of the models will have exact positions of possible snow events nailed at this range.

Edited January 10 by Chesil View

[Harveyslugger]

1 hour ago, Penguin16 said:

Certainly doesn’t look like a screaming unstable northerly is on the cards. Looks pretty dry further west, eastern areas exposed to a northerly look best placed for snow showers after northern Scotland. Pretty underwhelming overall compared to a few days ago for late weekend/early next week on current guidance.

How many times do people have to say this.disturbances will pop up closer to time and the west could have a pembrokeshire dangler.

[nick sussex]

The outputs get there in the end .

More general agreement in the overall pattern with a brief northerly then the shortwave to the nw complicates things as this cuts off the Arctic flow .

Likely then low pressure to the sw will try and move in with some snow on the frontal boundary .

The Arctic air once again tries to edge south after that point .

The timeframe day 6 into 7 still remains a danger time as that’s the period where some interaction could take place between the sw low and low heights / shortwave energy to the ne  heading s sw .

You’re relying on sufficient forcing to edge the pattern se and push that lobe of high pressure near Iberia and into France away at that point .

So no major dramas this morning so far but this isn’t a done deal just yet .

A few more runs needed there . 

The colder northerly has a Green light .

The snowy frontal boundary and cold extension remains on Amber for the timebeing .

That might be revised after the ECM , hopefully ! 

Edited January 10 by nick sussex

[Harveyslugger]

1 hour ago, Cheshire Freeze said:

UKMO D7…all the ingredients for a snowstorm shortly after at D8.

I’d say if you’re in the Midlands you’ve got a good chance of a decent snowfall next week.

What about south Wales?kinda in line with Midlands

[That ECM]

Just now, Harveyslugger said:

What about south Wales?kinda in line with Midlands

Gfs op and control and a couple of gefs. The point being they’re pointless but come on the op.

[feb1991blizzard]

5 minutes ago, nick sussex said:

The outputs get there in the end .

More general agreement in the overall pattern with a brief northerly then the shortwave to the nw complicates things as this cuts off the Arctic flow .

Likely then low pressure to the sw will try and move in with some snow on the frontal boundary .

The Arctic air once again tries to edge south after that point .

The timeframe day 6 into 7 still remains a danger time as that’s the period where some interaction could take place between the sw low and low heights / shortwave energy to the ne  heading s sw .

You’re relying on sufficient forcing to edge the pattern se and push that lobe of high pressure near Iberia and into France away at that point .

So no major dramas this morning so far but this isn’t a done deal just yet .

A few more runs needed there . 

The colder northerly has a Green light .

The snowy frontal boundary and cold extension remains on Amber for the timebeing .

That might be revised after the ECM , hopefully ! 

Much better this morning, decent length of spell - great that its all amber & green, usually shortwave and green don't go together, usually i think of red.

[That ECM]

1 minute ago, feb1991blizzard said:

Much better this morning, decent length of spell - great that its all amber & green, usually shortwave and green don't go together, usually i think of red.

I find these two fascinating as it shows to me the cold is winning. Look at the low differences in 12 hours. I’m not suggesting ukmo has it nailed by the way.

[nick sussex]

Just now, feb1991blizzard said:

Much better this morning, decent length of spell - great that its all amber & green, usually shortwave and green don't go together, usually i think of red.

The northerly albeit brief is safe now . I’ve green lighted that ! 

The reason the shortwave isn’t on red is the models agree that there’s enough forcing to edge the pattern se at the right time .

I’ve kept the amber because of that troublesome high to the se . You generally don’t want to see that . The models manage to flatten it and usher it away .

I’m hoping the ECM will add a bit more margin for error to proceedings . 

Perhaps if we ask nicely !

[feb1991blizzard]

2 minutes ago, That ECM said:

I find these two fascinating as it shows to me the cold is winning. Look at the low differences in 12 hours. I’m not suggesting ukmo has it nailed by the way.

Yes, belter - ensembles not terrible for Plymouth, margin for error improving all the time.

[nick sussex]

The ECM and UKMO are similar at T120 hrs with the straighter flow over east Greenland and western Norway .

The GFS has the bulge ! 

[Lukesluckybunch]

Trough west of Greenland..is further west this time..it may come to stronger push into Greenland at 144..

[That ECM]

1 minute ago, nick sussex said:

The ECM and UKMO are similar at T120 hrs with the straighter flow over east Greenland and western Norway .

The GFS has the bulge ! 

[Turnedoutniceagain]

16 new pages since I went to bed - must be an UPGRADE !!!

ICON's thrown in a shortwave to spice things up 

[That ECM]

T144. Micro analysis beyond is fi 

[Captain Shortwave]

The models moving towards a cold but rather dry initial northerly as pressure rises quickly and the winds veer more westerly again. However this feature north of Scotland needs watching.

[That ECM]

Tops off a good morning’s output, people will worry about 850’s but I’m happy with the theme.

Edited January 10 by That ECM

[KTtom]

5 minutes ago, Captain Shortwave said:

The models moving towards a cold but rather dry initial northerly as pressure rises quickly and the winds veer more westerly again. However this feature north of Scotland needs watching.

Ecm 168 synoptically is great, but the shortwave above has killled the uppers for southern areas!

Edited January 10 by KTtom

[Lukesluckybunch]

Just now, That ECM said:

Tops off a good morning’s output.

Perhaps uppers too mild or not?would it be snow

[NorthYorksWeather]

Quite a shift north for cold air on EC this morning for day 6/7 when comparing with yesterdays 0z EC run. 

[The Northern Ramper]

If the usually negative 0z is an upgrade then we should be in for a positive day.

[Kasim Awan]

1 minute ago, NorthYorksWeather said:

Quite a shift north for cold air on EC this morning for day 6/7 when comparing with yesterdays 0z EC run. 

Yes, all output has shifted to the GFS at day 6/7.

[That ECM]

2 minutes ago, Lukesluckybunch said:

Perhaps uppers too mild or not?would it be snow

Too far out to worry. We don’t have a set up as per gfs op 24 hours ago.

[IDO]

Well, there you have it, EC is finally moving towards that surface high that delays the northerly at D6-7:

It has proven again that it is no longer the top dog. The low from the Azores now moving towards the UK, and 850s are disappointing at D7:

GFS clearly as of 0z better modelling in the last two days.