Model Output Discussion - cold spell to end Autumn

[snowking]

1 minute ago, bluearmy said:

the gefs running at 32 km surely aren't going to upset anyone !

the eps at 14 km are similar res to ukmo op. I suspect that's why they are using them.

Yep, the GEFS mean really will be a legitimate example of some of the chatter from a couple of weeks back about watered down ensemble means

Just to pick up on the conversation from earlier too re: UKMO 'ensembles', I suspect these will be the MOGREPS -r ensembles...

[ghoneym]

1 minute ago, bluearmy said:

the gefs running at 32 km surely aren't going to upset anyone !

the eps at 14 km are similar res to ukmo op. I suspect that's why they are using them.

Fair point BA, as was mentioned in the thread earlier still 11 runs to go. I personally think the jet stream is being overhyped by the GFS, they have it ramping up big time from now to Sunday from the US eastern sea board across the Atlantic towards the uk and I believe they have a tendency to overdo it. the vorticity effect on the slider will, in part, be determined by the jets speed and track and that being the case, if it is being modelled too strongly then would the slider low meander eastward or stay on a south / south west track?

[chris55]

40 minutes ago, bluearmy said:

I’m quite surprised that they are using ens at such a short range 

I guess it relates to the uncertainty re the ineteraction of the trough with the upper trough and also the small wedge of heights thrown up ahead of the slider which is varying in intensity 

what chance do us mere mortals stand to make a call !!

It makes sense blue

when looking longer range, with the obvious spreads, is a no brianer. But with the continued uncertainty of exact track and flow and the interaction with the trough out east an ensemble average seems sensible.

i should imagine its quite rare, if this was an "all rain" system it wouldn't really matter. But the fact that disruptive snowfall could have a big impact locally means getting the forecast as accurate as possible is pretty important for warning etc, and even at such short range, with uncertainty, the ensemble spread is the only way to go.

[Mark wheeler]

Navgem with the little bubbles like one of models yesterday I think it was the ECM.

[Frosty.]

Looking at the GEFS 12z mean, much colder for all tomorrow and saturday, sunday less cold in the south, still very cold in the north. Next week cold, especially in the north until around or just after mid month and then trending a little less cold...in a nutshell, the word cold is likely to be used a lot to describe the UK weather and most of us will see snow at some point, some more than others.

[feb1991blizzard]

28 minutes ago, bluearmy said:

the gefs running at 32 km surely aren't going to upset anyone !

the eps at 14 km are similar res to ukmo op. I suspect that's why they are using them.

Yes, but in any case, ive looked at ens means before in run up to cold spells, they aren't much cop when it comes to PPN type, probably because that's not what they are designed to be used for!

[mother nature rocks]

21 minutes ago, Britneyfan said:

Wow the snow is going to be for the far north of the uk on that run! Even midlands misses out 

Not if the Arpege is to be believed. Has Sunday as an all day snow event from south mids to northern England.

[craigore]

49 minutes ago, Frosty. said:

Here are my highlights of the coming days from the Gfs 12z which show a very wintry spell with a mix of snow showers, persistent snow, ice days, severe frosts, high windchill, not your typical uk mild gunk is it!????

For your neck of the woods maybe.

The south east stays dry ( Wet on Sunday) if cold throughout.

Sorry but this is no U.K wide Freeze..

Just a cold spell , wintry mix for some wth frosts . Lets have some perspective..

Its the cold from the east we need , but none to tap in at this stage of the Winter.

More Seasonal than normal though i agree.

[Summer Sun]

Arpege has Wales in the firing line for snow on Sunday cut off point looks to be around Yorkshire

Edited December 7, 2017 by Summer Sun

[karlos1983]

1 hour ago, pyrotech said:

I have to agree in your location, thats a little too far south for this set up, however i do hope you get something over next week or so.

There is South and then SOUTH - Bournemouth and other coastal towns are not really in the running, But Hills further inland  Dartmoor etc do have opportunity as does Mendips etc 

How every dare you  

off the Christmas card list ✖️

What a lovely way to start the working week this will be 

[Glacier Point]

EC is midlands jackpot

[bluearmy]

Just now, Glacier Point said:

EC is midlands jackpot

low centred east midlands - slightly north of ukmo

[JamesL]

t48 on ecm 

[Mark wheeler]

Ecm 72

Looks further south to me , let’s see.

And then , a bit windy down south 

Edited December 7, 2017 by Mark wheeler

[SMU]

2 hours ago, shaky said:

The midlands gets a pounding on the ukmo 12z!!with the gfs going south aswell its a good start steve!!

ECM 72

brutal for the midlands but still wiggle room south ( & north )

[bluearmy]

Pretty good agreement except the occlusion is se from the low on ukmo whereas it will be across to Holland to the furthest low in the trough extension on ecm 

Edited December 7, 2017 by bluearmy

[Glacier Point]

very similar aerial coverage on EC12 to EC00 initially, but more southern coverage late Sunday into Monday. Take a blend of EC and UKMO

Edited December 7, 2017 by Glacier Point

[shaky]

3 minutes ago, Glacier Point said:

very similar aerial coverage on EC12 to EC00. Take a blend of EC and UKMO

Gp the midlands could be in a very seriious situation 3 days from now if ecm comes true!coould be really high snow totals across the area!

[snowray]

Latest T72 Fax. Very interesting indeed, theres a wave developing along the front, and its slightly further south too. Very cold chart with lots of snow stalling around the Midlands I'd say.

Edited December 7, 2017 by snowray

[Singularity]

Run for the storm shelters - oh wait, we have no storm shelters...

[Johnp]

3 minutes ago, snowray said:

Latest T72 Fax. Very interesting indeed, theres a wave developing along the front, and its slightly further south too. Very cold chart with lots of snow stalling around the Midlands I'd say.

Ooh now I'm getting interested...

[high ground birmingham]

This is far from resolved. Even though the Midlands is in a good position, the models can easily shift 100 miles here or there. I think tomorrow's 12zs may resolve the issue fully and finally. 

[bluearmy]

1 minute ago, Singularity said:

Run for the storm shelters - oh wait, we have no storm shelters...

Gonna feel raw despite it not snowing in the se !

[Singularity]

1 minute ago, bluearmy said:

Gonna feel raw despite it not snowing in the se !

Where would you place the snow line BA? Looks a bit of a blizzard for some 

[alexisj9]

4 minutes ago, Singularity said:

Run for the storm shelters - oh wait, we have no storm shelters...

Woah that is rather deep. We could be in some bother if that comes of.