Model Output Discussion - Into 2024

[northwestsnow]

EXETER UPGRADE ALERT

Edited January 9 by northwestsnow

[It Might Snow]

It is worth reading the latest mid and long range Met Office updates. It seems to update on the App before the main website and so make sure you veiw it on the App.

Edited January 9 by It Might Snow
Grammar

[Rob 79812010]

Good set of latest ensembles. Expect beeb to lower temps at 21st 22nd. Met seem to be more on it to me

[Harveyslugger]

2 minutes ago, northwestsnow said:

EXETER UPGRADE ALERT

Met office siding with ecm and ukmo then?

[northwestsnow]

2 minutes ago, Harveyslugger said:

Met office siding with ecm and ukmo then?

Well that's debatable but they talk of snow showers and potential for disruptive snow ,oh and lots of frosts.

Only snag is they are unsure of timing and location.. 

Edited January 9 by northwestsnow

[Met4Cast]

The most interesting aspect of the MetO update is the complete lack of the word "rain" across the entire forecast period, "snow and sleet" featuring a few times. This suggests to me that they are not making much of any 'milder' incursions. 

Either way, unsurprisingly they are not in camp GFS but very much favouring the EPS/UKM/MOGREPS blend & probably GloSea6.

Edited January 9 by Met4Cast

[damianslaw]

Cutting through each op run so far today.. looking at general direction of travel for next week:

 

- A northerly airflow almost certainly will develop through the weekend. How cold and how far south it digs open to question.

- Heights to the west and north west may not be strongly robust against the cold air spilling out of eastern USA seaboard, but enough to send any injection into the jet on a more southerly course

- whilst the jet may see some added fuel next week, after a week of being inactive in our neck of the woods, it still looks quite weak to me, and consequently the denser colder air invasion should fend it off for a bit

- end result, suspect north half UK will stay in cold air throughout next week, with a question on where the polar front lies, the boundary line could be a magnet for significant wintry precipitation, sliders and trough disruption territory.

In this scenario, I fully expect future model runs to play around with low heights attacking the cold block in various guises. Sometimes barrelling them through the UK, other times sending them south into France, others will disrupt and slide them, the odd rogue one, most likely GFS culprit will send them packing north and exposing UK to mild air. 

Edited January 9 by damianslaw

[Chrisover93]

36 minutes ago, Ali1977 said:

UKMO is holding out because it’s the correct outcome  read John holmes post above , that’s a confidence booster and likely the METO Deep dive later will be similar 

Yeah in fairness I think John is hitting the button with this one here I just don’t see the Atlantic just walking back in the cold weather would have been here over a week by then also 

 

42 minutes ago, johnholmes said:

Tuesday 9 th Jan

NOAA 6-10==15-19th, in other words inside the approximate date of ‘deep’ cold predicted some time ago.the 6-10 chart keeps the meridional flow across the chart, the shape is not the classic one but no signal for a developing mobile Atlantic, not on the 8-14 really. As usual the high +ve anomaly is much reduced but this is normal. IF this persists and the upstream becomes less conducive to another trough-ridge downstream then a change could be signalled but not so far and the 8-14 takes us to 17-23rd Jan?

ECMWF has never been as +ve about the deep cold scenario and its latest output for 15-19 Jan is pretty similar. The 850’s show the -5C extending during the period to cover all of the UK by the 15th then it is moved north again so that by the 19th is is predicted be N Wales to about the Wash area. This as the 500 flow backs more west or even south of west with time.

UK Met of course only shows surface and 500MB outputs for 3 days (13-15 th) but it looks to be on the same page for just prior to the two above from the 15 th. Ridge dominated both 500 and surface, over/just NW of the UK to a more trough dominated by the end of its run, again surface and upper air.

So overall then, after a temporary slight warming at the surface and height, over the weekend a deeper colder spell seem likely to occur. The direction of flow, initially, being N’ly not E’ly. Looking on Extra at the skew-T diagrams, the colder air seems to start arriving over Doncaster by 14 Jan and much colder air continues to advect into the area from a N’ly direction as far as the run goes=T+180. All the time with limited convection, to around 6000 ft. So even well inland it is ‘possible’ for snow to fall. This is way ahead of any reliability from the synoptic models so patience is needed as to just what will happen over the UK regarding snowfall. Be that from showers and any possible troughs in the flow or from the Atlantic trying to move in giving more general ppn.

To me it seems unlikely that milder air is unlikely to make much, if any, real progress against the cold airmass in the period under discussion on this post.

All really interesting though to see just how the actual weather will turn out.

 

[Alexis]

1 hour ago, Malarky said:

Interesting thing found on the internet… some temperature difference.

 

 

Yeah, all goes back into the freezer at 144hours though.

[Rob 79812010]

8 minutes ago, Met4Cast said:

The most interesting aspect of the MetO update is the complete lack of the word "rain" across the entire forecast period, "snow and sleet" featuring a few times. This suggests to me that they are not making much of any 'milder' incursions. 

Either way, unsurprisingly they are not in camp GFS but very much favouring the EPS/UKM/MOGREPS blend.

The met update looks fantastic to me. Is this the 'deep dive' being referred to?. I can't remember many forecasts like this in recent years. In fact, given the slight shift on the ensembles and the latest met update, I'm now thinking that the last week of Jan may actually stay on the cold side. There are people on hear with considerably more knowledge than me, but things seem to keep creeping in the right direction. I get the model swings are scary sometimes but keep calm, all is well for coldies. I think!!!

[Malarky]

3 minutes ago, damianslaw said:

Cutting through each op run so far today.. looking at general direction of travel for next week:

 

- A northerly airflow almost certainly will develop through the weekend. How cold and how far south it digs open to question.

- Heights to the west and north west may not be strongly robust against the cold air spilling out of eastern USA seaboard, but enough to send any injection into the jet on a more southerly course

- whilst the jet may see some added fuel next week, after a week of being inactive in our neck of the woods, it still looks quite weak to me, and consequently the denser colder air invasion should fend it off for a bit

- end result, suspect north half UK will stay in cold air throughout next week, with a question on where the polar front lies, the boundary line could be a magnet for significant wintry precipitation, sliders and trough disruption territory.

In this scenario, I fully expect future model runs to play around with low heights attacking the cold block in various guises. Sometimes barrelling them through the UK, other times sending them south into France, others will disrupt and slide them, the odd rogue one, most likely GFS culprit will send them packing north and exposing UK to mild air. 

I am feeling mildly excited. Bet Sheikhy is too. More runs needed!

[Froze were the Days]

9 minutes ago, northwestsnow said:

EXETER UPGRADE ALERT

The amount of times I've heard that the last few days...then looked and been underwhelmed.

[northwestsnow]

1 minute ago, Froze were the Days said:

The amount of times I've heard that the last few days...then looked and been underwhelmed.

I think it's the first time they've mentioned disruptive snow ..

It's got to be an upgrade, hasn't it ?

[Froze were the Days]

2 minutes ago, northwestsnow said:

I think it's the first time they've mentioned disruptive snow ..

It's got to be an upgrade, hasn't it ?

I take it that must be from that low moving in from the south west against the Am airmass?...that's 8/9 days away! 

[northwestsnow]

GLOSEA has updated ...

06z v 0z

[Battleground Snow]

13 minutes ago, Met4Cast said:

The most interesting aspect of the MetO update is the complete lack of the word "rain" across the entire forecast period, "snow and sleet" featuring a few times. This suggests to me that they are not making much of any 'milder' incursions. 

Either way, unsurprisingly they are not in camp GFS but very much favouring the EPS/UKM/MOGREPS blend & probably GloSea6.

The "with winds from the north or north-east " caught my attention in the extended.

Perhaps ties in with this mjo chart form the ecm

Btw does anyone know if the met office mjo chart is publicly available anywhere?

I've asked them in the past, but they they just blank me

06z ecm is consistent with the 00z run in the early timeframe 

Edited January 9 by Battleground Snow

[Chrisover93]

2 minutes ago, Met4Cast said:

The most interesting aspect of the MetO update is the complete lack of the word "rain" across the entire forecast period, "snow and sleet" featuring a few times. This suggests to me that they are not making much of any 'milder' incursions. 

Either way, unsurprisingly they are not in camp GFS but very much favouring the EPS/UKM/MOGREPS blend & probably GloSea6.

Agree met office are going for the cold for sure 

[Nick2373]

06z well i don't know what Exeter are seeing but all I'm seeing on the 6z is just under average temps with a climb to just above from the 22nd onwards, South looks to be falling to just average conditions on every run, I cant wait for the 12z to roll out because quite frankly that's a rubbish chart if its cold and snow your after. 

 

[Jacob]

GFS P09 looks perfect for blizzards for the south

[Mcconnor8]

2 minutes ago, Nick2373 said:

06z well i don't know what Exeter are seeing but all I'm seeing on the 6z is just under average temps with a climb to just above from the 22nd onwards, South looks to be falling to just average conditions on every run, I cant wait for the 12z to roll out because quite frankly that's a rubbish chart if its cold and snow your after. 

 

Their own modelling does look much colder so they must have their faith in that rather than the GFS, even though there could be frontal snowfall opportunities on that as well.

[IDO]

The Met Office deep dive on YT suggests what most of us have interpreted from the recent model runs. The low(s) arriving from the Azores interact with cold air over the UK on late Tuesday and the possibility of a snowline over the UK. Looking at Manchester North on their graph, they advise low confidence in the sweet spot.

This ties in with the general trend: cold moving south from the weekend and possibly a snow event mid-week. After that is where it gets even trickier! Indeed, the web update does not suggest that the GFS outlook is their best guess. It suggests an Atlantic high/ridge, which I am unsure what makes them think; maybe cold zonal with an NW to SE diving jet is feasible.

We wait for D8-10 to be resolved before I take that seriously.

 

[Chrisover93]

1 minute ago, IDO said:

The Met Office deep dive on YT suggests what most of us have interpreted from the recent model runs. The low(s) arriving from the Azores interact with cold air over the UK on late Tuesday and the possibility of a snowline over the UK. Looking at Manchester North on their graph, they advise low confidence in the sweet spot.

This ties in with the general trend: cold moving south from the weekend and possibly a snow event mid-week. After that is where it gets even trickier! Indeed, the web update does not suggest that the GFS outlook is their best guess. It suggests an Atlantic high/ridge, which I am unsure what makes them think; maybe cold zonal with an NW to SE diving jet is feasible.

We wait for D8-10 to be resolved before I take that seriously.

 

Manchester north is absolutely awful 

 

we want it from the south coast we deserve an event 

[Paul_1978]

29 minutes ago, northwestsnow said:

EXETER UPGRADE ALERT

Still showing last updated Tuesday wherever I look - website and app.

EDIT - scrap that, it IS Tuesday!!

Edited January 9 by Paul_1978

[Harveyslugger]

Just now, Paul_1978 said:

Still showing last updated Tuesday wherever I look - website and app.

It's Tuesday today?

[Nick2373]

Just now, Paul_1978 said:

Still showing last updated Tuesday wherever I look - website and app.

It is Tuesday