Model output discussion - deep cold inbound?

[Easton Luna Boys]

26 minutes ago, BarnetBlizzard said:

Am i the only one thinking GFS 12z and the ensembles are looking a bit iffy for those further south? 

Tbh I think more caution needs to be applied for those south of the midlands. Some are banking -10 uppers on a 'clean' Easterly feed but at this range, it's far from certain. There's just too much warmer air in the mix to our south east. Get more of a SE feed and the likes of Kent could be more concerned about flooding rather than the white stuff. Remember; cross model agreement is <T48!

[MattStoke]

1 minute ago, Man Without Beard said:

Based on all the models I've seen in the past 24 hours, this is my interpretation, well it was a picture or 1000 words  

Looks about right to me As always with every weather chart, graphic and forecast, I’m right on the line between 2 different scenarios

[Guest]

11 minutes ago, kold weather said:

GFS ensembles are getting increasingly snowy, to go along with the GEM and the GFS.

Increasingly confident that there is going to be a metric shed load of snow around. Regardless of perhaps some marginality briefly on Monday for the SE, it is increasingly becoming more confident of a decent snow event coming up.

 

Unless you are in the south, hardly inspiring for supposedly what is the best spell of the past few winters......

[georgiedre]

2 minutes ago, Man Without Beard said:

Based on all the models I've seen in the past 24 hours, this is my interpretation, well it was a picture or 1000 words  

Looks good really. although living in nw wales what is weird is that we tend to do well from North Easterlies probably due to to Liverpool Bay and picking up moisture from there. 

[Guest]

EA could hit the jackpot, we usually do well in these setups! Brace yourselves for  popup snow events especially when the Atlantic fronts try and make inroads, South West areas could get buried! 

[Djdazzle]

Trying to pin down how much snow at this range is a fast track to the loony bin!

Things change at 12 hours away, so not much chance at T96!

[kold weather]

5 minutes ago, Man Without Beard said:

Based on all the models I've seen in the past 24 hours, this is my interpretation, well it was a picture or 1000 words  

I'd personally expect there to be more widespread snow showers further west than where you have it mate, the 12z suite so far has really upped the amount of snowfall around it has to be said.

Probably somewhere like IoW roughly northwards from there based on the 12z runs tonight, though of course it will reduce in numbers the further west you go.

[sheikhy]

Right another quick crayon job!!!if we want a good start we need to see the following!!low over the uk go south and not deepen too much at the same time (red)!!more disruption going further into europe (black line) and you will then get that lovely cold air advection heading in (blue)!all this for the 72 hour chart..

Edited February 3, 2021 by sheikhy

[Man With Beard]

8 minutes ago, sheikhy said:

I think you better move that line that is on the border of east anglia further west and the one over the north midlands further south

I'd like very much to move all the lines further south and west! But taking into account all of the runs (and not just the most recent ones), this is my interpretation of the middle ground. 

[tight isobar]

Until Saturday afternoon.. no snow totals/possibilities/advancement inland.. rates etc are worth noting >viewing... the only definitive part atm.. is that some will do well..@(understatement)....

[Man With Beard]

5 minutes ago, kold weather said:

I'd personally expect there to be more widespread snow showers further west than where you have it mate, the 12z suite so far has really upped the amount of snowfall around it has to be said.

Probably somewhere like IoW roughly northwards from there based on the 12z runs tonight, though of course it will reduce in numbers the further west you go.

I ran out of space on the page to include more detail for central south 

I definitely hope there will be more snow for southern and western areas that I've suggested

Edited February 3, 2021 by Man Without Beard

[Timmytour]

6 minutes ago, chris55 said:

It looks like we have good model consensus on the initial easterly flow making it to the entire UK. Those in the extreme south/south west will always be close to the boundary, but overall, I think we can say an easterly flow is very likely with some very cold air. 

Looking back to 2010, and these are some of the coldest charts we have seen since then. The  Synopotic/broadscale pattern is one I can not ever remember seeing at such short range!

Once the flow gets established we have lots of options of where things could go, none even close to a normal UK winter! Going forward, after the initial easterly,  we have a few main options,

1 The Atlantic tries to push in but gets forced south east....those in the south west quarter of the UK get a blizzard.

2 The easterly flow sustains, those in the east continue to get buried with snow showers and streamers, those in the west get some snow and overall we all stay cold.

(1 or 2 most likely)

3 The Atlantic lows makes inroads and pushes the cold north, the boundary moves north and the blizzards are pushed north.

4 The Atlantic wins, mild for all.

 

Whatever happens its going to be one hell of a fun ride!!

I like this, but does the option also exists whereby pressure builds to such an extent from the north it pushes the jetstream further south so that,, while a very cold airflow over us is maintained, things are relatively dry all over barring a few flurries near some eastern coasts?  I can't see this myself in view of the ferocity of what is coming off the northeastern part of America, but does it deserve being mentioned as a horse in the race nonetheless?

[Mike Poole]

1 minute ago, Timmytour said:

I like this, but does the option also exists whereby pressure builds to such an extent from the north it pushes the jetstream further south so that,, while a very cold airflow over us is maintained, things are relatively dry all over barring a few flurries near some eastern coasts?  I can't see this myself in view of the ferocity of what is coming off the northeastern part of America, but does it deserve being mentioned as a horse in the race nonetheless?

Hmm, dry easterly, I’m not sure but if an easterly is going to be dry, it is dry from the outset as the high pressure isn’t far enough north to start with.  That’s not the ballpark we are in, and I would be surprised if the jet running so far south it is bone dry is an issue for the foreseeable.

[sunnijim]

2 minutes ago, Timmytour said:

I like this, but does the option also exists whereby pressure builds to such an extent from the north it pushes the jetstream further south so that,, while a very cold airflow over us is maintained, things are relatively dry all over barring a few flurries near some eastern coasts?  I can't see this myself in view of the ferocity of what is coming off the northeastern part of America, but does it deserve being mentioned as a horse in the race nonetheless?

More than a possibility that imo,seems it is how Exeter might see it judging by their long rangers.

Ironically ( given what we see from the models at present) it might just be the South and parts of the East prone to snow,while the North becomes dry and frosty.

[snowhope]

16 minutes ago, Man Without Beard said:

Based on all the models I've seen in the past 24 hours, this is my interpretation, well it was a picture or 1000 words  

This picture and your thoughts have saved the mods 1000 moved posts! This is what the vast majority want to know when they come in here. You cannot get much simpler and better interpretation than this for the up and coming Cold Spell and will answer a lot of peoples questions. Well done Sir!

[pyrotech]

14 minutes ago, Man Without Beard said:

Based on all the models I've seen in the past 24 hours, this is my interpretation, well it was a picture or 1000 words  

I have to say, that is quite a good summary of the main potential this next week. All those lines can be adjusted in every direction and some surprises are likely too. i would add that the middle band could change to heavy snow followed by rain, but i am really in hope that does not happen.

I have a sneaky feeling that this may be a rare occasion where a satellite image shows all areas of mainland UK with a covering of snow. The potential is definitely there.

[Tim Bland]

37 minutes ago, kold weather said:

This is the ECM operational from the 00z fwiw:

Thats probably a realistic worst case scenario at the moment to be honest!

It was something of an outlier with regards to the wind direction though which suggests its handling the low differently to the other models.

BTW Jason, the GEM is a heck of a gem for you guys, I used to live in Thurrock and this airflow would be leaving extremely excited.

Wouldn't rule out thundersnow in this sort o set-up btw! I'm an alumni of the Thames streamer!

I think the far south east being too marginal is a very short term issue (mon am) and by mon on its back to snow. I actually didn’t realise this morning that the WX site was having issues and I was viewing the 12z run lol. That was a very snowy run for almost everyone! Let’s hope it’s about to be repeated! 

[Weathizard]

Bit of a rubbish GFS mean really for longevity of cold, it’s starting to look like a 3/4 day potential event, rather than the potential freeze suggested a few days ago. 

[Don]

15 minutes ago, Alderc said:

Unless you are in the south, hardly inspiring for supposedly what is the best spell of the past few winters......

That's subject to change several times between now and then.  Was always going to be knife edge for the south but everyone is in with a chance at least!

[Neilsouth]

1 minute ago, Weathizard said:

Bit of a rubbish GFS mean really for longevity of cold, it’s starting to look like a 3/4 day potential event, rather than the potential freeze suggested a few days ago. 

 

As if it was very reliable with its dart board lows lately, even ECM took awhile to catch back on!

[chris55]

Before the EC starts rolling..... can we just appreciate and admire the NH pattern on the UKMO 144. Im in awe to be honest!

A very very rare chart, and one we should save for the next 10 winters when its all TPV over Greenland!

 

[Paul]

It's really busy, there's a lot of great stuff being posted, but also too many posts aren't model related. We all need to muck in together here so everyone can enjoy reading/taking part, so please keep it to the models and don't respond to off topic posts  

[Don]

22 minutes ago, Man Without Beard said:

Based on all the models I've seen in the past 24 hours, this is my interpretation, well it was a picture or 1000 words  

Can't really complain with that and just about on the right side of the line for significant snow midweek!  Lots to watch in the coming days for sure with minor twists and turns benefitting some and maybe not others so much.

[Scott Ingham]

45 minutes ago, nick sussex said:

I hope people appreciate your  honesty and reluctance to spin things . Because the forecast for southern areas is more complicated than further north . 

 

I agree with both of you.

As it currently stands the south and east is the right side of conditions and even looks like receiving a LOT of snow but it doesnt have the same wriggle room as areas further North which for me are nailed on now for at least 3-5 days of deep cold. 

For these areas south we still need a days more runs id say.

If i was to take a punt though all areas including the south east are in for a very very respectable cold spell with periods of snow

[SLEETY]

24 minutes ago, Man Without Beard said:

Based on all the models I've seen in the past 24 hours, this is my interpretation, well it was a picture or 1000 words  

You forgot to add much uncertainty next week, regarding more disputive snow in the s and  SW or possibly further north into the Midlands. 

Depends on the track of the low pressures trying to get into the SW if they even make it. Even the MET have no idea  yet. Hopefully your guess of mainly rain in the South is miles out.