Wow, upgrade from UKMO, thu/fri looking very interesting for some 

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Not sure what is going on here ! We can assume that the UKMO has 'thrown one in' untl we see other output -

https://www.meteociel.fr/ukmo/runs/2018120912/UW96-21.GIF

 

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[snipped a lot of stuff about how it wasn't that cold "up north"]

It is therefore on that basis as well, that I referred to that period as not being all that cold.

Uh-huh, I understand that where you were that easterly in late November wasn't special. Down here it was - snow from the east is unusual at any time, but that was the earliest it's happened since November 1993.

Nice to see the MetO is serving up some sub-528 dam air down here for a time late next week, from the east. That's colder than the 0z run and that had 4C as a maximum here on Thursday (the long-term mean would be 9C or so). I'll be interested to see what MOGREPS makes of it later.

 

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GFS further west also 

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GFS further west also 

Not really, only tiny differences between the output so far and the 06z - GFS has been very consistent for some days.

 

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Not really, only tiny differences between the output so far and the 06z - GFS has been very consistent for some days.

 

-4 isotherm further west than 06z, so it is further west 

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Not sure what is going on here ! We can assume that the UKMO has 'thrown one in' untl we see other output -

https://www.meteociel.fr/ukmo/runs/2018120912/UW96-21.GIF

 

Why because the Atlantic hasn't bombed through

Next Saturday shows the Atlantic held off 

Actually ties in with what Darren was saying earlier 

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Yes the GFS has consistently shifted everything westwards a little with each run.

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Well, well the UKMO run has thrown the cat amongst the pigeons , Atlantic doesn’t get in at all.

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GEM comes to the party too at T+96!!!! Sorry can’t post charts.

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Nice to see the GFS is also backing away from a simple blast-through too. By 102 the axis of the disrupting trough over the UK is over the south coast rather than northern England - and heights are lingering for longer over Scandinavia.

It's not on the scale of MetO, but that (and ECM) are sniffing something which GFS is reluctant to pick up on.

Talking of MetO, that 144 chart is tantalising. A chunk of heights from the ridge heads west over Greenland, coinciding with a weak ridge moving eastwards from Canada. That has the effect of squeezing the life out of that upper trough complex to our west, which slows the pattern down in our neck of the woods. It's like watching a pebble slowing down the flow of water in a stream...

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GEM comes to the party too at T+96!!!! Sorry can’t post charts.

http://www.wetterzentrale.de/maps/GEMOPEU12_96_1.png 

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Awsome UKMO tonight....

Wow- what a turn around in 48 hours- Cant say it wasnt expected.....

Awsome UKMO tonight....

Wow- what a turn around in 48 hours- Cant say it wasnt expected.....

I'd suggest waiting for the ensembles and further output. ECM Det. was not representative of it's ensembles this morning.

 

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GEM comes to the party too at T+96!!!! Sorry can’t post charts.

See below 

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GEM is fascinating. Remember that easterlies are (in)famous for causing a low-level cold feed to come in off the Continent which - as we saw last month - is perfectly capable of cooling down to snow-bearing levels in just a couple of days.

Have a look at these precipitation charts (only available on Meteociel AFAIK):

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=66&mode=2&carte=2

Run foward a few frames and you'll see areas of light rain, light freezing rain and light snow coming in from the east. What's going on there is that the snow-supporting layer of air is really thin - so much so that it's raining above it in some cases, which then becomes freezing rain as it passes through the cold layer.

As an Atlantic front then moves in it mixes the air up and leads to "proper" snow on its leading edge.

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=144&mode=2&carte=2

Fascinating stuff and a nightmare for forecasters.

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The ECM hinted at a change this morning, but the UKMO 12z is a real beauty for the time of year. Easterly is back on the table....

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Snow next Sat for many if the GEM 12z is right.

https://www.theweatheroutlook.com/twodata/gem.aspx?run=12&charthour=144&chartname=ukpreciptyperatec&chartregion=uk&charttag=Precip%20type%20rate

 

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Not sure what is going on here ! We can assume that the UKMO has 'thrown one in' untl we see other output -

https://www.meteociel.fr/ukmo/runs/2018120912/UW96-21.GIF

 

Totally plausible given the background signals

😂😂😉

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Not sure what is going on here ! We can assume that the UKMO has 'thrown one in' untl we see other output -

https://www.meteociel.fr/ukmo/runs/2018120912/UW96-21.GIF

 

When even the BBC week ahead forecast at 1:15pm today was emphasising "high uncertainty" from mid-week onwards, we can assume nothing for sure at this time, Ian.

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