Model output discussion 25th Jan - The final third of winter beckons..

[Seasonality]

10 minutes ago, Summer Sun said:

Bitterly cold air building just over the channel -11's in the SE

Nice! Our Dutch friends here on the forum would enjoy that. Ice skating on the canals for the likes of @ArHu3 and @Dennis

[warrenb]

1 minute ago, Luke Attwood said:

Very cold even with not cold uppers?

The ice day the other week was when uppers were well above 0

[AWD]

1 minute ago, Weathizard said:

What? High pressure is far too close for the majority of the UK on the 12z when the uppers are at the coldest, like I said comparably to the 6z high pressure is having far more of an influence. Very strange reaction by yourself? I didn't say it was a bad run.

Are you referring to the 12z UKMO, 12z GFS, 12z Arpege, 12z GEM or 12z JMA as they are all subtly different in 500mb, 850hpa & 500hpa wind vector, thus they all have differing surface weather for the UK, especially eastern areas?

Worth noting, as I am sure has been said before on here, that the 850hpa temps are far less irrelevant to surface temps and potential snow when from an ESE direction, more important factors are dewpoints and DAM heights in our forecast scenario.

[Frosty.]

1 minute ago, warrenb said:

The ice day the other week was when uppers were well above 0

True, +5 uppers in places, this week they look like plummeting to -10 or lower..can't wait! 

[Stu_London]

Just now, Linda said:

Sorry mods off topic but can I ask posters to remember when they are posting and describing the models that we don't all live in the south east -I have noticed on descriptions lots of people getting excited about their back garden but please try and make it more relevant to the whole of the Uk

Problem is that conditions are likely to vary quite widely over the whole of the uk, so any commentary provided would be rather generic and not very specific

[Luke Attwood]

3 minutes ago, warrenb said:

The ice day the other week was when uppers were well above 0

Oh thanks.so u expect it to stay cold throughout the weekend ?

[bryan629]

Arpege advetising a rain to snow event for much of northern england 

6z                                                                   12z 

     

Possibly continental undercut ? 

http://www.meteociel.fr/modeles/arpege.php?map=330

 

[Ice Day]

A cracking UKMO and decent GFS (GFS FI is excellent) and don't get me started on the GEM - fabulous.  Could it be one of those rare occasions where all roads lead to cold? Maybe just maybe February 17 could be 'the' month we've been waiting for?  Let's hope the ECM doesn't spoil the mood.

[seaside 60]

4 minutes ago, Luke Attwood said:

Oh thanks.so u expect it to stay cold throughout the weekend ?

The best place is to go to your regional discussion, not ask everyone on here.
This is talk about what the models show and not how long will it be cold.
Said in the best friendly way of course.

[Wilxy]

Right that's the GFS done, a great run again with plenty of cold opportunity, we have the ENS to follow then the ECM, I love this time of model watching when you just don't know what could be about to happen so we all become glued to are computer screens!

I still think that we will get a second wave later in the month which will most likely give us the best chance of widespread cold, whilst what were seeing at the moment is the building blocks being put into place.

 

 

 

[karyo]

The 12z GFS is beautifully blocked and cold throughout FI and absolutely stunning stratospherically with a perfect split vortex!

[Snowyowl9]

32 minutes ago, feb1991blizzard said:

How the hell did you only get freezing rain in 1987???   -    The uppers were -15c in your neck of the woods.

Early feb 1986 and forget which month in 1996 which gave some freezing drizzle was the most noticeable.

UKMO very cold continental air starts on Thursday,SEly bitter like a week last Thursday/Friday.

And that's just the start.

 

[Nouska]

29 minutes ago, karyo said:

The 12z GFS is beautifully blocked and cold throughout FI and absolutely stunning stratospherically with a perfect split vortex!

Oh yes indeed!

I bet there are few examples of that in the archives - stunning wedges of heights over both ends of the axis - that split should last a while.

Edited February 5, 2017 by Nouska

[Singularity]

So UKMO still cuts off the low faster but GFS shows via resumption of the strong NE flow well NW of us that the block could still stand reasonably tall under his scenario - and the wave 2 can still be sufficient to produce a vortex split. Very encouraging indeed.

If the 00z ECM had been like the previous 12z we'd have full agreement on LP racing through Greenland but being unable to flatten the block due to decent support from low heights over S Europe and the Med.

So... let the ECM 12z today be on a par with - or better than - that of yesterday! If it isn't I will seriously be wondering what's up with the workings behind it.  

[Allseasons-Si]

Cracking set of 12z this afternoon and again the gem was very good with it's projections just like a couple of days ago when i posted the animation that the cool pool was the last stop for the uk,you can see that separation of cool pool S of Scandi and again the last stop is the uk,although not as cold it has -16 uppers just across the channel so not bad consistancy there

 

[karyo]

9 minutes ago, Nouska said:

Oh yes indeed!

I bet there are few examples of that in the archives - stunning wedges of heights over both axis - that split should last a while.

What's even better is that there is consistency with the 6z chart.

[lassie23]

Weather for the week ahead on the BBC weather site mentions a progressively colder week with a blocking high to the east and by next weekend, snow showers could start to effect eastern England.

[shotski]

10 minutes ago, Nouska said:

Oh yes indeed!

I bet there are few examples of that in the archives - stunning wedges of heights over both axis - that split should last a while.

Great news for us cold lovers but not great for arctic sea ice I would imagine. 

[Man With Beard]

53 minutes ago, Summer Sun said:

Bitterly cold air building just over the channel -11's in the SE

And it just sits there for days.

Could the UKMO repeat the trick ... but over the UK?

[Duane S.]

14 minutes ago, Nouska said:

Oh yes indeed!

I bet there are few examples of that in the archives - stunning wedges of heights over both axis - that split should last a while.

That's a proper split. Great to see it isn't the standard top down strong 1hpa split which struggles to get down to let alone 5mb and therefore has little net effect. Potential ramifications of this are pretty evident. Late winter 2013 revisited.

Edited February 5, 2017 by s4lancia

[karyo]

1 minute ago, shotski said:

Great news for us cold lovers but not great for arctic sea ice I would imagine. 

Sadly, the Arctic ice is at a record low even without the split. It is doomed regardless of whether we manage to get the cold here or not.

[Frosty.]

3 minutes ago, lassie23 said:

Weather for the week ahead on the BBC weather site mentions a progressively colder week with a blocking high to the east and by next weekend, snow showers could start to effect eastern England.

Snow showers should begin to affect eastern areas on thurs / fri according to the Gfs 12z..looking forward to this Easterly a lot!

[Methuselah]

Well then, whenever the snow showers start to affect Eastern England, a fine set of 18Zs will, following all the recent model-related trauma, do me fine...18

[Duane S.]

Just now, Ed Stone said:

Well then, whenever the snow showers start to affect Eastern England, a fine set of 18Zs will, following all the recent model-related trauma, do me fine...18

We have to get through the ECM first!

[snowray]

1 hour ago, Matty M said:

UKMO 120hrs is a good chart. Nice clean chart. GFS looks very mess to the SW.

 

Yes GFS a bit all over the place, short ensemble there for London, goes from the coldest member to the mildest.