Model output discussion - Christmas approaches

[Paul]

Please continue with the model discussion here - could we see a white Christmas this year?

[Radiating Dendrite]

Let's christen this one with a boooooom!

[ITSY]

Where's Ian Brown when you need him

[sheikhy]

This aint done yet!!that shortwave is still to further west on ukmo and it looks like the control is goin west based at 150 hours!!

[IDO]

GEM also onboard with the synoptic of Greenland wedge and undercutting Atlantic so just ECM for a full house:

Obviously the finer detail is to be resolved, and a few runs to make sure no backtracks, but looking good...

[northwestsnow]

UKMO is stunning.

❤

[E17boy]

Its all in your hands now 

[Notty]

2 minutes ago, ITSY said:

Where's Ian Brown when you need him

I think Codge is here under a different name though …

Sorry for OT

[IDO]

On 16/12/2021 at 16:51, sheikhy said:

This aint done yet!!that shortwave is still to further west on ukmo and it looks like the control is goin west based at 150 hours!!

Yes, having this pattern is what we want, but getting the best from it is going to be the next tease. 

[Mike Poole]

GFS is an absolute cobra run, just look at the cold late on Christmas evening!

[ITSY]

In all seriousness, the GEFS is showing the shift at soon as T+150. See the 06Z: 

And now on the 12Z, watch how the high has been shunted north west and the atlantic into more of an undercutting phase to the west of Ireland, helping to draw the continental feed further SW. Could still swing the other way...

What a said a few days ago remains. I want to see the below before getting too overly confident

1. Inter-model consistency

2. Inter-run consistency 

3. UKMO support from Exeter 

What we *may* now be seeing is (1) together with (3) - I've seen a few UKMO pros on twitter tweeting about the mixing of airmasses over xmas today. Small signs...

[sheikhy]

2 minutes ago, northwestsnow said:

UKMO is stunning.

❤

Wait for the 168 hour chart!!!we need to be carefull!!

[Lukesluckybunch]

4 minutes ago, sheikhy said:

This aint done yet!!that shortwave is still to further west on ukmo and it looks like the control is goin west based at 150 hours!!

control looks like will make it

[Paul]

Interesting discussion around the snow risk. 850hpa temps aren't the best guide on their own. I'd recommend using the 850-1000 thicknesses for a better indication - you're looking for blues on these maps for any chance of snow, but the deeper the blue the higher the risk. 

[E17boy]

 

[Met4Cast]

Will never understand this forums of shutting down threads just because there's a lot of pages, don't see what difference it makes but there we go. 

12z ENS are an improvement, more amplification on the high and a better NW>SE alignment of the energy in the Atlantic. With the UKMO shifting towards the ECM (albeit not quite fully making it), momentum towards a cold and potentially snowy Christmas period is picking up.

[Eagle Eye]

I'm ready for a BOOM with the next few runs I'm calling it

[Paul]

Just now, Met4Cast said:

Will never understand this forums of shutting down threads just because there's a lot of pages, don't see what difference it makes but there we go. 

 

If you saw the load on the database you'd maybe not say that! It's something to do with the software which means large threads with lots of posts happening create more load than threads with < 100 pages or so. 

[feb1991blizzard]

Just now, Met4Cast said:

Will never understand this forums of shutting down threads just because there's a lot of pages, don't see what difference it makes but there we go. 

12z ENS are an improvement, more amplification on the high and a better NW>SE alignment of the energy in the Atlantic. With the UKMO shifting towards the ECM (albeit not quite fully making it), momentum towards a cold and potentially snowy Christmas period is picking up.

Slows the site down - long threads do, too long to load.

[Snowman.]

3 minutes ago, Lukesluckybunch said:

control looks like will make it

Too far north. 
 

We want the point of contact to be in the channel/northern France so everything north of that low pressure is easterly. 
 

 

[Singularity]

I think GEM may have got a little carried away with the transfer of very cold air along the southern flank of the blocking high. Triggers excessive LP development within an already overly deep Atlantic trough as it merges with the one over Scandinavia.

Potentially cold UK-wide by 27th or so but we'd have to get through a windy mix of rain and snow beforehand.

...but as I say, likely a bit OTT with the lows. In any case, I'm over-analysing individual model runs here!

[Mapantz]

On 16/12/2021 at 16:57, Met4Cast said:

Will never understand this forums of shutting down threads just because there's a lot of pages

It becomes overloaded and the thread will slow down, that's why it gets refreshed. 

[Kasim Awan]

 

5 minutes ago, Met4Cast said:

Will never understand this forums of shutting down threads just because there's a lot of pages, don't see what difference it makes but there we go. 

Imagine 350 users refreshing a 250 page thread every minute, that's 87,500 pages loaded a minute, on an already resource heavy forum software.

Edited December 16, 2021 by Kasim Awan

[Pixel]

12 minutes ago, Paul said:

Please continue with the model discussion here - could we see a white Christmas this year?

Maybe 

[Snowman.]

1 minute ago, Singularity said:

I think GEM may have got a little carried away with the transfer of very cold air along the southern flank of the blocking high. Triggers excessive LP development within an already overly deep Atlantic trough as it merges with the one over Scandinavia.

Potentially cold UK-wide by 27th or so but we'd have to get through a windy mix of rain and snow beforehand.

...but as I say, likely a bit OTT with the lows. In any case, I'm over-analysing individual model runs here!

I would put it down to the Norwegian low being too far West. It phases before fully clearing south causing a potentially horrid set of weather events.

Its far too knife edge for my liking, give me a classic BFTE with convection over the channel low stuff. Despite the later being capable of extreme totals.