Model Output Discussion. 3/12/2022. How cold will it get?

[Ali1977]

29 minutes ago, swfc said:

 the ground won't be frozen boss.

Why not, -5c most of the U.K. by Thurs night - close to ice day in the shortest weeks of the year then another severe frost by Fri night for many. Surely a decent crunchy top few mm’s ??

[sheikhy]

Low further east at 90 hours and a move towards icon at 84 hours near norway!

[northwestsnow]

GFS is looking very good here ..96

 

Edited December 4, 2022 by northwestsnow

[Ali1977]

Thurs will give many the possibility of seeing a few flakes

[Ali1977]

And this looks better aligned too compared to the last run.

[TSNWK]

Just now, Ali1977 said:

And this looks better aligned too compared to the last run.

Link to mother ship stronger.. and noticeable shift east of the trough drop when you flick between 12z and 18z nice.. and smidge colder uppers showing as consequence 

[bluearmy]

What may become more apparent is stronger ridging se from the greeny heights which may hold the Azores low in situ whilst it loses some of its depth ….

[Battleground Snow]

The much maligned low in the Atlantic may actually be of benefit to us pushing WAA into Greenland to reinforce the block 

[Howie]

1 minute ago, bluearmy said:

What may become more apparent is stronger ridging se from the greeny heights which may hold the Azores low in situ whilst it loses some of its depth ….

Yes I was thinking the low might stall 

[stodge]

3 minutes ago, bluearmy said:

What may become more apparent is stronger ridging se from the greeny heights which may hold the Azores low in situ whilst it loses some of its depth ….

Yes - that ridging holds the east based negative NAO in place and forces Atlantic LP east or south east into Europe - absolutely vital.

[BlueHedgehog074]

3 hours ago, damianslaw said:

I'll say it again stick to 96-120hrs tops, and expect swings from the models at timeframes beyond from run to run.  In the reliable becoming cold for all, very cold in the north, with high snow risk from Wednesday onwards becoming widespread and further south in time.

 

Though I’m guilty of using this model quite a bit lately (mostly for fun), to prove your point regarding the swings that occur at timeframes beyond 96 to 120 hours, the 12Z NAVGEM goes a much different route to how it handles that tropical grumpy spinner later this week in relation to models such as the 12Z ECMWF:

The Greenland ridge dangles quite far South occupying the Northern mid-Atlantic. This keeps the angry spiral (storm) locked up near the coast of Eastern Canada on the South-Western side of the Greenland ridge. At best, it makes little shifts Eastwards. Due to what happens upstream, and probably due to some of the high heights South-East of the Scandinavian Low, the UK stays under the chilly Scandinavian trough for a while. Very wintry looking for the UK it looks.

Compared to the 12Z ECMWF below for a similar time period, that stormy Low to the South-West of the UK doesn’t get trapped that easily, though just slowly makes it’s way East/North-East towards the UK. 

 

Except at the start, the Greenland ridging is less influential. The Southern flank of the High isn’t as amplified not dangling down as far South through the Northern mid-Atlantic. The angry Low has an easier time escaping further East. That angry Low could clearly be a friend of snowy weather for the UK, at least some areas of it, if it behaves itself and not go too far North. But not certain enough yet as to how exactly it behaves.

Despite the model we’re dealing with, it can be hard to admittedly place much faith in the NAVGEM. It’s solution kinda feels like the odd one out of the operational models, so probably unlikely (confidence would increase a bit should GFS 18Z become manipulated by the NAVGEM. And then have other models following along with growing ensemble support). But I think it’s trapped stormy Low idea could be considered an option. Just like how the GFS in the last few runs has been powering up Low Pressure around the Iceland area.

The above comparison, however, is just a way to prove that operational models can vary wildly beyond certain timeframes - at least sometimes. Depending also on the pattern the models are dealing with. I guess we all all have our own instincts and desires as to how we feel things evolve. Plus we can all see things in different ways when looking and summarising model output, which can then lead to some highly varied analysis. 

Edited December 4, 2022 by DiagonalRedLine

[northwestsnow]

[TSNWK]

3 minutes ago, northwestsnow said:

Link to vortex?

[sheikhy]

What a brutal run up to 162 hours!!!you really cant hope for any better!!its quite something!!

[northwestsnow]

Heatwave in Turkey

Baltic in Britain

30 years of hurt....

Wooooosh..

[Battleground Snow]

Just now, sheikhy said:

What a brutal run up to 162 hours!!!you really cant hope for any better!!its quite something!!

Icelandic wedge, surely sends that low packing to the south, but never know with the GFS 

[stewfox]

1 hour ago, RabbitEars said:

Nick please could you pop up a chart showing the shortwave of which you speak? I can't access the charts at the moment and am interested as to why and when it might disrupt. 

Short wave and a long wave . All in FI of course 

[terrier]

Wow that’s some brutal cold so far on the pub run. Lots of snow potential for many so far.

[Lampostwatcher]

Gfs 18z 

Winter proper starts Thursday 

High chances of snow from Thursday to monday could pop up an❄🌨❄ywhere 

[Ben Sainsbury]

1 minute ago, Battleground Snow said:

Icelandic wedge, surely sends that low packing to the south, but never know with the GFS 

Absolute corker. Beginning to develop our own cold pool over the UK with the slack low overhead. Can see it since 850s aren't mixing out.

[Bats32]

Potential for something special here.

[northwestsnow]

If EC looks like this at day 8 tomorrow the place will be in a frenzy ...

[tight isobar]

Underlying prognosis- good in the range plotted.. however the range and notions for a rolling sequence Scandinavian block format is beginning to catch the eye...

[nick sussex]

The shortwave has landed but heights rising east and ne of it .

No probs if it phases with the Atlantic low that far west . Let’s bring on a Scandi high now .

[weirpig]

Off course Jff. But not often the southeast sees regturns like this