Model output discussion - Winter has arrived and the hunt for cold is on

[Polar Maritime]

The Models continue to show a cool/cold unsettled N/W PM flow into next week and beyond, With snow over high ground in the North. Some snapshots from the UKV early next week..

[BLAST FROM THE PAST]

12 minutes ago, carinthian said:

Morning all, I still cannot get over what changed the models to drop the first chart scenario shown only 3 days ago . Both GFS and ECM and a lesser so UKMO had the Polar Front diving well south and picked up that rather unusual placed low  to provide a threat of snow to the south. Gone now is the real chance of colder snowy weather by the end of next week as the real deep cold air  is held much north and the zonal train heads into Blighty. However, could or are the models due for another switch in 3 days time? Going by this weeks sudden flips , possibly on the cards. I think the common feature to draw on these runs is that for the most part, the UK seems to be on the colder side  of the Polar Front as it meanders across the North Atlantic. Our team report as being baffled as well but their own longer term model still has height rises to the NE as we head towards Christmas, read what you may into that .

C

It was interesting as it didn't edge away they just fell away.  But even I (a coldie) said I wanted to see it at t48 just for comfort .....interestingly though those charts are still 1 week away and a week is a long time in model world especially as pM air is very much the theme still ......although a less cold outlook is somewhat easier to hold onto than a deep cold one.   Also interested how the professionals weren't expecting that, be very interesting to hear more thoughts from them C?

 

BFTP

Edited December 6, 2019 by BLAST FROM THE PAST

[Anthony Burden]

Hi Carinthian your comment on pressure rise to the northeast showing on your longer term models I assume

being a low pressure battered Scandinavia,hope that is what you are referring to.

[carinthian]

17 minutes ago, BLAST FROM THE PAST said:

It was interesting as it didn't edge away they just fell away.  But even I (a coldie) said I wanted to see it at t48 just for comfort .....interestingly though those charts are still 1 week away and a week is a long time in model world especially as pM air is very much the theme still ......although a less cold outlook is somewhat easier to hold onto than a deep cold one.   Also interested how the professionals weren't expecting that, be very interesting to hear more thoughts from them C?

 

BFTP

Hi F, I do know they did not have that low on their own charts but more in line of a deep trough. But to drop that scenario shown by the big models took them by surprise. I am due for a call with later this morning and will try and fathom out their thoughts as to the reason why, but quite frankly not sure they will know ! In the meanwhile, our ski- lifts open today under warm sunshine , +10c on the slopes this morning.

C

[MATTWOLVES 3]

Most definitely an improvement from the ECM mean this morning....only a week into December, and already we are on for 

chase no2.. Probably at least 100 more yet...

Edited December 6, 2019 by Mattwolves

[StretfordEnd1996]

4 minutes ago, Mattwolves said:

Most definitely an improvement from the ECM mean this morning....only a week into December, and already we are on for 

chase no2.. Probably at least 100 more yet...

Wouldn't that be chase #3 perhaps? The recent one, next week and - this new one we're trying to find? 

Joking apart though, that is to me a continued sign that up until D10 there's very much a cooler spell of weather coming up with only 1 or 2 milder interludes - its just a shame that that has translated into nothing more than a weak shot of cold from the NW/N next week. 

ECM D10 looks like it has the plausibility to go on from there and produce some proper goods if it came off, but it's very similar to the D10 chart we saw yesterday.

GEM not too dissimilar

GFS not really seeing it 

A bunch of ensembles around that time frame still looking at cold uppers but in my opinion the main pieces of information I can gather from the ensembles this morning as far as the longer term goes (beyond D10) is the amount that show something much more milder.

[carinthian]

31 minutes ago, Anthony Burden said:

Hi Carinthian your comment on pressure rise to the northeast showing on your longer term models I assume

being a low pressure battered Scandinavia,hope that is what you are referring to.

Yes Anthony, its applies to day 10 -15 outer range profile charts. They expect the 300mb winter jet to be much further south by this time, so its fairly natural to expect some form of height rises to the NE to develop. The detailed day to day forecast profile is nay impossible that far out of course but you would expect low pressure to dominate still over much of the British Isles buts its positioning would be crucial to what type of weather to expect but at a guess with the jet forecast to be well south of the British Isles, cold PM air mass would be favourite to reside. Whether height rises over Scandinavia develop or not, any forecast charts that far out must be taken with a pinch of salt but its being shown !

C

[Iceaxecrampon]

GFS 00Z

Well it's an upgrade  - as early as Wednesday

That's RAW on the tops

00Z had the Channel LP running in for a forum meltdown although T+324

Positive output compared to yesterday.

Edited December 6, 2019 by Iceaxecrampon

[snowray]

43 minutes ago, StretfordEnd1996 said:

Wouldn't that be chase #3 perhaps? The recent one, next week and - this new one we're trying to find? 

Joking apart though, that is to me a continued sign that up until D10 there's very much a cooler spell of weather coming up with only 1 or 2 milder interludes - its just a shame that that has translated into nothing more than a weak shot of cold from the NW/N next week. 

ECM D10 looks like it has the plausibility to go on from there and produce some proper goods if it came off, but it's very similar to the D10 chart we saw yesterday.

GEM not too dissimilar

GFS not really seeing it 

A bunch of ensembles around that time frame still looking at cold uppers but in my opinion the main pieces of information I can gather from the ensembles this morning as far as the longer term goes (beyond D10) is the amount that show something much more milder.

Yes this will be the 3rd chase already, I have been counting. 

Anyway, a very wet election day on the 06z, with some snow in the North on high ground.

[Iceaxecrampon]

Just a reminder of wind speeds for Sunday nights system

976 - 980mb NW

Edited December 6, 2019 by Iceaxecrampon

[Anthony Burden]

Many thanks Carinthian for your return comments very informative.Regards Anthony.

[weirpig]

very Windy  next few days coming up   Eire could bear the worst of it  over a more sustained period   but one model  The Arpege 6z   (which we know sometimes overcooks windspeeds)   shows  for early Monday  winds hitting close to 90 mph  through North Wales   north west and  into the heart of England    surely its way overcooking the speeds   but that would present a real danger 

 

[snowstorm27x]

4 minutes ago, weirpig said:

very Windy  next few days coming up   Eire could bear the worst of it  over a more sustained period   but one model  The Arpege 6z   (which we know sometimes overcooks windspeeds)   shows  for early Monday  winds hitting close to 90 mph  through North Wales   north west and  into the heart of England    surely its way overcooking the speeds   but that would present a real danger 

 

Am I reading that right Wierpig is that 130mph in the Midlands.

[weirpig]

Just now, snowstorm27x said:

Am I reading that right Wierpig is that 130mph in the Midlands.

crikey  hope not  is  KMPH    over 80mph 

[Jordan S]

Yes the Arpege did show a small swathe of 60+mph for more central regions.. This is the midnight run.. 

But not nailed on Gfs doesnt have it as strong. 

Here's the Ecm.. 

Edited December 6, 2019 by jordan smith

[Ali1977]

59 minutes ago, carinthian said:

Yes Anthony, its applies to day 10 -15 outer range profile charts. They expect the 300mb winter jet to be much further south by this time, so its fairly natural to expect some form of height rises to the NE to develop. The detailed day to day forecast profile is nay impossible that far out of course but you would expect low pressure to dominate still over much of the British Isles buts its positioning would be crucial to what type of weather to expect but at a guess with the jet forecast to be well south of the British Isles, cold PM air mass would be favourite to reside. Whether height rises over Scandinavia develop or not, any forecast charts that far out must be taken with a pinch of salt but its being shown !

C

The last GFS FI did seem to suggest a slackening of the PV and height rise to our NE , and the Jet diving south under it , so it’ll be interesting to see if the 06z and the ENS pick up on this theme. 

Edited December 6, 2019 by Ali1977

[snowstorm27x]

1 minute ago, weirpig said:

crikey  hope not  is  KMPH    over 80mph 

Oh yh I just looked seen it lol. But 80mph could still be very dangerous if it comes to fruition. Also It looks if a third chase is on the cards much better 06Z today.

[booferking]

If we could only get this output in the reliable very snowy setup for some.

[Methuselah]

Bucket-loads of sleet/wet snow...? 

[Iceaxecrampon]

3 minutes ago, Ed Stone said:

Bucket-loads of sleet/wet snow...? 

Mmmm Sleet

[booferking]

6 minutes ago, Ed Stone said:

Bucket-loads of sleet/wet snow...? 

Sleet in south i would think white gold up north.

[Ali1977]

Day 10 looking pretty wintery for the North as mentioned, freezing level at around 300m Or less for N England and Scotland so pretty much anyone could see it there. Day 10, chance of this being reality is 0%, but still nice to see.

[StretfordEnd1996]

That's a proper old W/NW'ly flow there that manages to produce the goods .. very rare do you get these types of flows bringing in such chilly uppers and snow potential these days but that is what would happen if it came off

Models trying to firm up on something a little more organised in the way of colder weather around D7-10 perhaps?

[Man With Beard]

The EC ensembles have now clearly ditched the idea of a trough sinking due south of us for election day:

But by 18/12, it's trying again on at least 3 clusters. How do you feel - once bitten, twice shy?

Watch out for potential height rises to the east just before Christmas (not necessarily in a location that will aid UK cold):

 

[Methuselah]

5 minutes ago, Ali1977 said:

Day 10 looking pretty wintery for the North as mentioned, freezing level at around 300m Or less for N England and Scotland so pretty much anyone could see it there. Day 10, chance of this being reality is 0%, but still nice to see.

Well Ali, you know what they say (we are in the run-up to a General Election, after all)...0% is better than nothing!