[Model Output Discussion - the cold has arrived]

Although we all have our own varying length and styles as to the messages we write on here, I just want to say I have been particularly impressed with the posts on here this morning, and same for last night). So much great information, great knowledge from a lot of you (wish I had some of that more technical/scientific knowledge some here have ). Makes it a rocking site to be on. 

Not much to add really, although for the Low that tries to come in from the West towards the later weekend, I feel there could be enough time for it to come in a more of a negative tilt, or in a shape and position to bring more of a South-Easterly flow ahead of it. Further delaying the speed milder 850 hPa air getting sucked up from the South to bring a more longer spell of snow on the forward edge of the front. Something like the below:

The GFS 06Z, nonetheless, brings a brief spell of sleet and snow for some Central England, Northern Wales areas, and then further Northwards, during the Sunday morning:

 

Northern UK high ground and hills no doubt seeing the best of the wintry conditions and some accumulations especially could easily occur on some of the Northern hills before the less cold/milder conditions spill in.

How much of any snow away from Northern UK high ground, other places could get depending again how that Low out West/South-West comes in, including the amount of influence the Greenland High puts on the Low and, as Nick Sussex pointed out before, how quickly that Low merges with the developing shortwave/Low around the Iceland area. 

An example from one of the GFS (12Z) runs yesterday showed that the Atlantic Low was still separate from that Icelandic shortwave/Low and able to throw a touch more of a surface South-Easterly flow ahead of it:

Because it’s still a few days away, if there’s still any chance for that Atlantic Low not to join forces with the Icelandic shortwave/Low too quickly as the Atlantic Low tries to push in further East/North-East towards the UK, the better. And also without the ridge/high heights to the East of the UK getting too much in the way. Could then mean the case of the Atlantic Low not just piling in a less cold/milder Southerly or South-Westerly flow Northwards through the UK too quickly (maybe with Northern parts still hanging onto colder conditions), and more of a pronounced snow risk for wider parts of the UK. Probably me just being too hopeful though, lol.

[Midlands Regional Weather Discussion]

Not quite as bone dry as what the cold spell might have appeared at first. Shows how surprises can happen 

Starting to see a few snowflakes invade the area again. Probably more to come for a number of us. 

[Model Output Discussion - the cold has arrived]

While the High Pressure is more concentrated towards Southern/South-Eastern Iceland on tonight’s 12Z ECMWF run, both 12Z runs from today and yesterday have been consistent with that Low out West slithering like a snake towards the South of the UK underneath the wedge/ridging to the North/North-West. Good boy, Low! And good job block for showing that Low who’s the boss around here.

Will help to keep the chilly weather going for many places. (For Monday 19th): 

Yesterday’s 12Z run:

Tonight’s 12Z run:

[Model Output Discussion - the cold has arrived]

2 hours ago, TEITS said:

Unlikely to be a snowy breakdown.

Quick summary from me is the less cold spell next weekend looks like being very shortlived. The ridge of high pressure bringing the S,lys will be shunted E and be replaced by low pressure. However because of the pressure remaining relatively high across Iceland/Greenland, the position of the jet stream and the passing of the low pressure will see the UK returning back to colder N/NE,lys. The likes of Scotland will hardly notice any warming up.

Sounds like a fair summary, TEITS, while I don’t think any of us can be sure as to how long a less cold period could last on the models, a lot of people believe this won’t last long. Is worth saying anyway that some of the long range height anomalies, including those such as the EC46, show higher than average heights continuing to our North-West. At least enough to feel that the Vortex still doesn’t want to take a long holiday over Greenland and Northern/Eastern Canada. Guess would then mean a continuation of a fairly quiet(ish) Jetstream across the Atlantic with not much for it to get fed off from, and no constant strong flat Atlantic Westerly drivern pattern invading our weather.

Just got to hope that the High Pressure areas and blocking continues to benefit the UK for further cold outbreaks for those that want it, even though it might mean some milder/less cold periods from time to time, especially for Southern areas. Though it would be quite a feat for all the UK to stay stuck in a cold spell everyday day from December till March. Winters, such as 1962/63 perhaps achieved, or got very close to, something like that, perhaps particularly Northern UK areas. 

Nearer time frame showing further cold and frosty conditions for many with a strong Greenland block and a flow generally varying between the North and East/South-East of the UK. While quite dry for some parts, chances of some snow at times for a few. Maybe with the Southerly tracking Atlantic/Azores Low producing a wintry surprise for some Southern parts next week. (Most places likely to miss out, but additional room for a few small(ish) South or North adjustments to mid next week’s Low affecting the distribution of where any sleet or snow falls over the UK - if it gets to the island at all)

[Model Output Discussion - the cold has arrived]

As I’m sure has probably been mentioned by a lot people in the past, changes to a milder/less colder outlook still feels fairly comfortably far away to get too alarmed about yet (but to be fair some of the possible trends being picked up towards a less cold/milder period is getting apparent). 

With this not being too certain at the moment, then how long any less cold/milder period lasts won’t seem certain either.

For the sake of it though, I hope any break to less colder or milder conditions goes off with a snowy bang.

[Model Output Discussion - the cold has arrived]

(Wasn’t expecting some of the comments yesterday, but is appreciated. I like to think most of us  try our best in here :))

For the cold weather fans (probably not the best precipitation charts to use), the GFS, UKMO and ECMWF unfortunately keeps most of the rai, sleet and snow just off the South Coast in the Channel during tomorrow. One or two odd pieces clipping the very far South and South-East, but most staying along and off the coast. There is some over some far South-Western parts of the UK and over parts of Western Wales. A bit over far Northern parts of Scotland with the ECMWF, in particular, showing a East to West line of precipitation/showers over some Central/Southern parts of Scotland:

00Z GFS

 

00Z ECMWF

Although the ECMWF does throw some precipitation up into some South-Eastern parts (West of London and over towards Kent way) during the early hours of Monday

 

00Z UKMO

And UKMO does a similar thing for Monday, albeit more over Kent

 

Who’s know, though. Maybe some of the precipitation tomorrow over the Channel and over parts of the very very far South could end up going further North than what’s modelled and give a few more a bit of a white goodie

Definitely going to come down to nowcastimg and window monitoring moments. 

[Model Output Discussion - the cold has arrived]

It’s kinda like the way we moderate the forums, including this thread. Some people may feel we’re too strict with the moderating, while some others might think we’re not tough enough. Can be difficult to get the right balance, but we can only do our best really  

[Model Output Discussion - the cold has arrived]

1 hour ago, Mike Poole said:

JMA rather lost the plot earlier in the run, but its worth posting the T264 as it has turned the vortex into a pram!

After the ECM, we probably won’t be throwing toys out of it!  Not today, anyway.

Just as well the pram covers a vast area of the Northern Hemisphere as the toys in it would have been too big to throw from.

The models make fine artists. 

I do wonder what sort of meal the 18Z GFS will be cooking up for us in FI? Hopefully something that includes (potato) wedges. 

[Model Output Discussion - the cold has arrived]

Out to 132 hours at the moment, but find it amusing the way all the circled cut-off Lows are organised on the 12Z JMA. Like some kind of choo choo train or parade  

[Model Output Discussion - the cold has arrived]

Have noticed the ECMWF, and particularly the UKMO, exhibit a wave feature across South-Eastern parts of the UK Wednesday next week:

00Z UKMO

 

00Z ECMWF

 

Precipitation associated with it is more widespread on the UKMO (probably due to the stronger and more bendier flow), albeit mostly affecting Eastern/South-Eastern parts. Might be something worth monitoring over future runs and see if other models start picking out something like this. Because even if the Azores/Atlantic Low not do much, it’s one way wintry events can come about through things like that. 

Do personally feel, having a wavy disturbance like that get to 00 hours, especially if it was like how the UKMO show it, the wintry precipitation would probably be a bit more expansive. Particularly with it coming off a mild/warm North-Sea. Just seems under-estimated on the above models. 

[Model Output Discussion - the cold has arrived]

 

30 minutes ago, Cold Winter Night said:

Week 5

Though super duper deep into the dreamland, I like how with week 5 the EC46 shows an area of lower than average heights just South of the UK perhaps suggesting a possibility of a Western European trough, although admittedly just a little shift East would be preferable. But would mean heights lowering to the South of the UK again (should anything like that happen 5 weeks away). 

[Model Output Discussion - the cold has arrived]

10 minutes ago, Captain Shortwave said:

ECM day 5

 

I don’t think this will be as clean as the UKMO as you can see a portion of the Azores low breaking away eastwards. The jury is out as to whether the parent low will follow or stall in the Atlantic.

 

The Low does seem to split into 2 puny pieces at 144 hours with a very cold Northerly to North-Easterly dominating the UK. -10*C 850 hPa temperature line close to Northern Scotland.

That would also be a nice wintry present for the South-East should some those ECMWF precipitation charts posted above for Sunday come off

[Model discussion highlights]

In summary, the models show further cold weather to come for the rest of this week into next week (and perhaps beyond, but far out to be sure). The pressure charts from the ECMWF below, while liable to some changes in some the later frames, shows an idea of the outlook for our part of the Northern Hemisphere for the next 6 days. 

Essentially High Pressure combined with high upper heights over the Greenland area, and a string of Low Pressure systems running along to our South and South-West. There is also a Scandinavian trough of Low Pressure extending some of its low heights and slack surface Low Pressure South-West over the UK further into this week and during the weekend.

Although the source of the cold is originating from the North and North-East for the UK, you can see the flow is slack (isobars well spaced out) and the flow will become variable over the weekend. Lack of winds should mean frosts continuing to form at night, especially inland with clearer skies at times. Could be some cold mist and fog too. Air cold and still enough for frosts to linger throughout the day, particularly in the shade. So will continue to feel like a Winter wonderland in many parts, especially for places that have seen fallen snow so far (latter mostly for some Northern areas and towards Eastern and Western coasts).

In fact, looks to be quite dry away from the coasts and Northern areas, bar one or 2 possible wintry surprises - these always have the possibility to catch people out unexpectedly. That is until sometime next week where you’ll see on the later frames of the ECMWF above that an angry, deep, Western Atlantic Low tries to slowly shift further East towards South-Western parts of the UK. This giving a strengthening chilly South-Easterly flow over South-Western parts heading into Tuesday and Wednesday next week as shown in the last 2 charts above.

With pressure from the Greenland blocking, it’s not yet clear whether this Low will party over the UK at all. Very very possible for the Low to just fully avoid the UK to the South and become squished and disrupted. May just find the blocking over Northern/North-Western UK could be too powerful and win the fight that Azores/Atlantic Low wants to start.

The Low does however have the chance of bringing a more organised area of rain, sleet and snow, with Southern areas of the UK probably seeing the best shot at this. Without that Low having any influence, cold and mostly dry conditions will probably continue to be the theme, nonetheless.  In spite of that, a more cyclonic flow between the North and East could easily be picked up next week sometime. It’s still at a range for that to be possible, particularly later next week. Plus some disturbances could easily pop about in the flow. This of which could drag more organised areas of sleet or snow further inland.

With how things could continue to go, an increased number of wellies and sledges could very well end up getting some attention at some point during the next week or so. 

Original post: https://community.netweather.tv/topic/98087-model-output-discussion-the-cold-has-arrived/?do=findComment&comment=4757158

[Model Output Discussion - the cold has arrived]

In summary, the models show further cold weather to come for the rest of this week into next week (and perhaps beyond, but far out to be sure). The pressure charts from the ECMWF below, while liable to some changes in some the later frames, shows an idea of the outlook for our part of the Northern Hemisphere for the next 6 days. 

Essentially High Pressure combined with high upper heights over the Greenland area, and a string of Low Pressure systems running along to our South and South-West. There is also a Scandinavian trough of Low Pressure extending some of its low heights and slack surface Low Pressure South-West over the UK further into this week and during the weekend.

Although the source of the cold is originating from the North and North-East for the UK, you can see the flow is slack (isobars well spaced out) and the flow will become variable over the weekend. Lack of winds should mean frosts continuing to form at night, especially inland with clearer skies at times. Could be some cold mist and fog too. Air cold and still enough for frosts to linger throughout the day, particularly in the shade. So will continue to feel like a Winter wonderland in many parts, especially for places that have seen fallen snow so far (latter mostly for some Northern areas and towards Eastern and Western coasts).

In fact, looks to be quite dry away from the coasts and Northern areas, bar one or 2 possible wintry surprises - these always have the possibility to catch people out unexpectedly. That is until sometime next week where you’ll see on the later frames of the ECMWF above that an angry, deep, Western Atlantic Low tries to slowly shift further East towards South-Western parts of the UK. This giving a strengthening chilly South-Easterly flow over South-Western parts heading into Tuesday and Wednesday next week as shown in the last 2 charts above.

With pressure from the Greenland blocking, it’s not yet clear whether this Low will party over the UK at all. Very very possible for the Low to just fully avoid the UK to the South and become squished and disrupted. May just find the blocking over Northern/North-Western UK could be too powerful and win the fight that Azores/Atlantic Low wants to start.

The Low does however have the chance of bringing a more organised area of rain, sleet and snow, with Southern areas of the UK probably seeing the best shot at this. Without that Low having any influence, cold and mostly dry conditions will probably continue to be the theme, nonetheless.  In spite of that, a more cyclonic flow between the North and East could easily be picked up next week sometime. It’s still at a range for that to be possible, particularly later next week. Plus some disturbances could easily pop about in the flow. This of which could drag more organised areas of sleet or snow further inland.

With how things could continue to go, an increased number of wellies and sledges could very well end up getting some attention at some point during the next week or so. 

[Will it be a white Christmas 2022]

Depends I guess how long this cold spell could last for. It could break down around Christmas, or even before. But if before, the cold could very well quickly return for Christmas. Mind, cold wouldn’t guarantee that snow could fall on the day itself, although it could always be very frosty depending on cloud cover, etc.

For this area, am probably going to go for a 30 - 40% chance for now. And maybe up to 50% further North (even though that might feel a bit optimistic lol).

[Model Output Discussion. 3/12/2022. How cold will it get?]

Just one thing to add is for anyone currently typing out a post, would recommend copying it and pasting it over to the reply box when the new thread is up rock and rolling. 

Also been quite pleased how the thread has generally gone. A good amount of great discussion along with good number of informative posts too. Something we hope will continue into the new thread. 

New thread is here:

 

[Model Output Discussion. 3/12/2022. How cold will it get?]

27 minutes ago, RainAllNight said:

You're on shaky ground there, mentioning in this thread that you wouldn't mind seeing some milder air at some point... "I mentioned it once, and I think I got away with it!" 

Not too worried We’ve got a whole stash of these in our Netweather pram store, so for anyone wanting milder weather in the models will be protected from any flying missiles in here if they wear one of these

 

Nothing much really to contribute towards the new 6Z GFS run, but in relation to its 00Z run, the Azores Low is more disrupted and squashed to the South-West/South of the UK.

00Z GFS

06Z GFS

Example used from Tuesday next week. Higher upper heights close by over South-West Iceland on latest run as well. Definitely still not solved yet. 

[Model Output Discussion. 3/12/2022. How cold will it get?]

1 hour ago, Portlander said:

Thanks for your reply. It’s hard to see the excitement without context.

I always think of snow as a distant relative coming to stay… great for a while, but the novelty wears off pretty quickly and you want things to get back to normal

Anytime, and I know what you mean  

Funnily enough, the way many models want to make this cold spell go on and on and on, I do wonder if some of us others will also start getting a bit tired of it and want something milder for a time. I really love the snow, frosty crispy days etc that Winter can bring, but if this was to go on for weeks, even I would probably get fed up of it

Could then make a chart like this from the GFS with the Southerly in FI be very appealing (albeit still chilly ahead of a front out West):

 

At least a fairly temporary milder flow from the South and South-West would be welcome. 

Be looking forward to what the weather has to offer for now from the models with some bright sunny days, frost and perhaps a spot of white stuff at times. Some have spoke on here before that with Winters that have had regular Northern blocking accompanied by prolonged cold spells, there can be briefer milder spells, particularly across Southern areas. 

[Model Output Discussion. 3/12/2022. How cold will it get?]

40 minutes ago, Mark wheeler said:

This was the the 12z , hopefully we can get an improvement. it was going under though. 
 

My take is all roads at the moment lead to cold . yayyyyyyy

Good ol’ NAVGEM trying to get the Low under. Has a South-Easterly track to it.

Apart from the way the GFS is trying to make things as complicated as figuring out a way out of a massive maze with the handling of the Azores/Atlantic low pressures next week, the favourite scenario today is to try to get the low pressure to push through to our South. At least it not causing much issues for putting a stop to the cold weather. Will likely take a few more runs or so to know for sure, but things have looked good today for these wanting longer lasting chilly conditions.
 

25 minutes ago, Delka said:

hope i don’t get a telling off for off topic posting but just had to say a little thankyou for all the knowledgable posts and updates on here, currently on my 3rd night staying with my grandad who’s on end of life care in the hospital and this threads been a big play in getting me by, obviously aided by what could be incoming

so yeah, thankyou! 

I’m afraid I’m gonna have to delete this post…

But in all seriousness, sorry to hear about what your Grandad’s going through. Some difficult times for some on here at the moment it seems. What ever happens, it’ll be all okay (even though I understand it will be tough for a while). Am glad the thread’s been of help to you and provides you with comfort - we’re always here for support

[Model Output Discussion. 3/12/2022. How cold will it get?]

1 hour ago, Portlander said:

1st post, long time reader over many years. Usually in the storm watching threads. Hi

Question… can anyone show me what a regular early winter chart looks like compared to the Synoptics that are around at the moment?

How far away are the blues and purples usually?

Hi Portlander, have used examples of charts on 7th December using a 10 year sample from 2005 to 2015:

You’ll notice there can be variation to the pattern from year to year. However, I think overall would say a typical early Winter chart is one where we get a flow off the Atlantic in general, which most charts above show in some from - usually between the South and West. Flow from the North-West can be fairly common too. The purples (from the Polar Vortex - low upper heights), tending to occupy us close by to our North and North-West around the Greenland area, especially towards Northern Canada. Along with this, Low Pressure systems on average take a South-West to North-East or West to East track through the North-West and North of the UK as they swirl around the upper low heights to our North-West/North.

This might not be the most accurate answer, mind, despite the amount of years experiencing Winters in the UK. (Some with more experience would probably be able to give a better answer), but hope it was of some help.  

Edit: Sorry, should have added welcome to Netweather  

[Midlands Regional Weather Discussion]

1 hour ago, Dancerwithwings said:

Yes I’ve had my eyes on that as well, we may see a dusting on the ground as we wake up come Friday morning

Here at 9:30pm it’s -1.7c and it’s frosty white all over outside….Winter is finally here

Could very well do  Would take even just a dusting. I think as longs we’ve got the cold in place, a snow event has got to turn up and put a dent over our Midlands snow shield at some point. 

But yep, a rime frost can still be nice, or just any frost (similar to today’s), as is better than nothing. Adds extra character to a Winter landscape. 

[Midlands Regional Weather Discussion]

It would be cool to see something at some point. Can only hope a surprise or 2 will come about (maybe a possible chance of something early Friday as Metwatch mentioned). 

[Model Output Discussion. 3/12/2022. How cold will it get?]

Unsure if the 168 hour chart has already been posted, but the 12Z UKMO between 144 and 168 hours stalls the Atlantic Low very close to the South-West of the UK. Where cold enough, apart from the very far South West where milder 850 hPa temperatures creep up, there could be over 24 hours of continuous snow/blizzards for Southern areas. 

34 minutes ago, Mike Poole said:

ECM ensemble mean T192, vortex looks like a butterfly with one wing missing…

Excellent mean chart.

Sure is. Kinda better than I had believed. Think a lot of people in here will be hoping the other wing doesn’t grow back. 

[Model Output Discussion. 3/12/2022. How cold will it get?]

1 minute ago, Quicksilver1989 said:

Yup an upgrade, compare the T850s from the 06z to 12z side by side....

Certainly a bit of a shift South-West of the cold. Same with the Atlantic Low. 

[Model Output Discussion. 3/12/2022. How cold will it get?]

6 minutes ago, Ice Day said:

GFS at 180 - have you ever seen a messier chart?

Deep into FI now so anything shown should be treated with a shed load of caution.

Tis amazing the serious lack of Vortex there is on the Western side of the Northern Hemisphere on that chart for that time. Canada and Northern America very nearly free of the blue blobs! Mainly just that fairly large piece dominating the Siberia area. It’s just not the Polar Vortex’s month. 

Really feels like at the moment, particularly in terms of that scheming Atlantic Low, that uncertainty in the models is around the 3+ day mark. But I do personally reckon, especially in comparison to yesterday, that the Atlantic Low looks more likely to slide/go under the UK, rather than smack through North-East. Is what it mostly seems like currently. I’ll promise to confess it if I’m wrong though

Before that, there is a number of cold and frosty days to undergo. Some snowy precipitation to go along with it, which although mostly affecting Northern UK parts and down coastal areas, some other parts of the UK could have the opportunity seeing a few little white flying saucers falling from the sky. Have to continue to keep a look at what the fronts/troughs do throughout tomorrow and Friday with regards to this. Even the weekend might produce a white treat for quite a few. Outside of any sleet and snow opportunities, the frost and bright weather should still make things feel festive. The blankets to keep ourselves warm are probably going to have a lot of great use as well.