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

[Mark wheeler]

4 minutes ago, Johnp said:

Lovely JMA at 156hrs 

I think a certain person knew right from the off that chart was coming .

[Mark wheeler]

16 minutes ago, bluearmy said:

there is a feature on meteociel 'activer live compare' which enables you to flick between the models for the same timeframe. also shows previous runs and indicates that todays ecm op is further west than yesterdays with the block. also better axis of WAA into the arctic. need to get the trough se T144/168

Thanks I've never spotted that .

[Captain Shortwave]

Better effort from the ECM, though still we have an issue with the cold pool running too far north towards the Baltic sea and stalls over Norway. The ECM does develop things upstream to allow the cold pool to finally move across the country.

   

Snow showers in eastern Scotland by day 7, a snow event in the south possibly with a weather system moving out of France across the south of England.

[I remember Atlantic 252]

snowy Saturday but deep FI!

[SMU]

Heavy snow for cornwall on the 192 ECM-

Thats a hens teeth special !!

[Banbury]

Decent run from ECM

Edited February 3, 2017 by Banbury

[snowice]

ECM 192 snow feast

[nick sussex]

ECM only gets  a 7/10. Energy heading to the Azores at T192hrs which will inflate a ridge in the Med. You need low pressure in the northern Med to cut off any chance of milder air heading nw.

 

[SMU]

Just goes to show that little better allignment from the JMA at 84 delivers this-

[Ali1977]

1 minute ago, Steve Murr said:

Just goes to show that little better allignment from the JMA at 84 delivers this-

Nearly as good as the GEM, great hour of forum viewing. Just need a good EPS and Pub run to end what started as a slightly subdued day with a bang 

[Frosty.]

9 minutes ago, Steve Murr said:

Heavy snow for cornwall on the 192 ECM-

Thats a hens teeth special !!

 

Big improvement on the Ecm 00z..let's hope for a big back loaded winter!

 

 

Edited February 3, 2017 by ajpoolshark
removed o/t reference

[cornish snow]

5 minutes ago, Steve Murr said:

Heavy snow for cornwall on the 192 ECM-

Thats a hens teeth special !!

This post i will blow up,print out and wall paper my lounge with,cheer's steve.

[A.J]

whilst it's oh so tempting to not do so, can we please try and avoid the 4 word post a/k/a the one-liner?......I've hit middle age, the eye sight is going, finger joints are starting to seize so it's getting harder to scroll down the page whilst squinting to pick out those morsels of good posts.......and besides, the other mods have asked a zillion times over for sensible model discussion and for ramps/moans to go in the correct thread....I thank you 

[Connor Bailey Degnan]

I can't see much if any excitement in today's 12z runs for snow.  Gem the exception. Though the ecm is very cold and frosty, it's a very dry easterly with maybe light snow showers affecting east, maybe some sort of 'event' in south West at 192 but that's a while away. As a snow lover, I'm very underwhelmed by today's output. Lets hope for upgrades, big ones!!!

[MR EXTREMES]

7 minutes ago, Steve Murr said:

Just goes to show that little better allignment from the JMA at 84 delivers this-

thats well with in forecasting range for jma 

[Duane S.]

23 hours ago, s4lancia said:

I sincerely hope nobody is downbeat as a fascinating and very positive (if you like snow) 12z suite draws to a close.

Let's look at what we have:

Cross model agreement on an Easterly of sorts in the mid term. Not in far away la la land. We can go whole winters without that happening.

 

Let's look at won't we don't have:

Absolutely anything nailed on. In fact, nothing could have occurred this evening in the chart outputs that would have ensured that. We are simply too far away from being able to crack open the champagne, but... every day we see these sort of outputs is day that we are a step closer to a potentially cold and snowy spell from the east.

 

So yes it very much could all go wrong but there is nothing showing tonight other than variances on an already established theme. i.e. no 'downgrades' and no trend to anything less cold. We can't ask for more than that...

I'm not even going to wait for the 12z ECM op to complete, it's largely irrelevant.

So if this time yesterday was good, then this time today is twice as good. Firstly because in the passing 24 hours there has been no TREND away from the onset of an easterly and more so, we are a day closer to it being nailed. (Nit) pick faults all you like, the Easterly (ranging from meh to a proper classic) is still VERY much in play tonight.

 

[Nimbus Nix]

ECM 216hrs actually shows a warm core subtropical cyclone off SW portugal which helps the Med ridge up through France:

[Frosty.]

8 minutes ago, Connor Bailey Degnan said:

I can't see much if any excitement in today's 12z runs for snow.  Gem the exception. Though the ecm is very cold and frosty, it's a very dry easterly with maybe light snow showers affecting east, maybe some sort of 'event' in south West at 192 but that's a while away. As a snow lover, I'm very underwhelmed by today's output. Lets hope for upgrades, big ones!!!

It looks like we are going to be flooded with cold air during the second half of next week, much better than the models were indicating recently..snowy set ups could be in the pipeline.

Get the deep cold air entrenched and the rest will take care of itself..I'm happy with the runs today, especially the Gem and Ecm..more upgrades please!!

Edited February 3, 2017 by Frosty.

[nick sussex]

Overall given the winter so far some nice outputs however theres an ingredient missing which would take this from 3 stars to at least 4 and that's low pressure hanging on over Northern Italy. If we saw this then there would still be a chance to get another area of deeper cold working west and it would also strengthen the flow into the UK and increase the convection.

Without that low then eventually pressure rises and then milder air from the Med works its way nw, it would be cooled however as it crosses a probably snowy central Europe but still if you get snow you want it to hang around.

I know this must sound ultra picky but we should aim high given how long its taken to get a decent looking set up.

Overall the ECM is an improvement and better than the 00hrs and its day ten chart looks like developing more amplitude upstream so less energy over the high.

 

[weatherguy]

Incredibly fine margins,  Lets take a look at the GEM against the ECM for the "perfect" run easterly.

 

Here we see the orientation of the LP to our west at +72h making a key difference by +96h.  Simply put, the GEM LP "squashes" more against the block and you get a greater negative tilt, which effectively spins the axis of the Scandy HP faster and rips that PV segment out over siberia straight for us.  With a very similar set up shown on the ECM, this does not happen as sharply, and therefore things don't pan out in quite so extreme a fashion.

This really shows by +120h.

The orientation of the Scandy high is less favourable, and the PV segment isn't dragged along with it.  Still a good chart for us, but nowhere near the "beasterly" of the GEM. 

Hopefully this rather simple explanation shows to the newer members how finely balanced these setups are for the UK, and how the models can "get it wrong" at such short range.  Minor differences by +72h can alter things drastically by +120h when trying to get the elusive beast from the east to our shores. 

[london-snow]

6 minutes ago, Frosty. said:

Get the cold air in place and the rest will take care of itself.

Famous last words there lol..

[Scandinavian High.]

21 minutes ago, Steve Murr said:

Its hard to explain quickly however if you look at both charts east of Finland you will see a 'blob' of blue - this is a chunk of the polar vortex thats sheared off moving towards Europe- 

If you really zoom in the GEM has it going SW as a wave, the ECM has it deeper ( because it has a partial phase with other energy ) & as a result its heading SSW

That small difference means the GEM gets that blob ( or 'lobe' ) of vortex all the way across europe, where as ECM holds it more to the SE ... There are other factors why but thats the main reason we are looking as we wanted them to be identical !

 

Thank you very much Steve for finding the time to explain and in way that I can understand It's your knowledgeable that helps us newbies long the line.

[craigore]

16 minutes ago, Frosty. said:

 

Big improvement on the Ecm 00z..let's hope for a big back loaded winter!

 

 

Whats wth the milder air in the S.E ?

 

[Duane S.]

14 minutes ago, Connor Bailey Degnan said:

I can't see much if any excitement in today's 12z runs for snow.  Gem the exception. Though the ecm is very cold and frosty, it's a very dry easterly with maybe light snow showers affecting east, maybe some sort of 'event' in south West at 192 but that's a while away. As a snow lover, I'm very underwhelmed by today's output. Lets hope for upgrades, big ones!!!

Firstly, if your benchmark for a good run is the GEM, may I politely suggest you relocate to the Arctic Circle because the times in recent years that such a run for the uk has come to fruition, you could count on one hand and still have fingers remaining.

Secondly, the rest of your post.

 

Edited February 3, 2017 by s4lancia

[Frosty.]

5 minutes ago, craigore said:

Whats wth the milder air in the S.E ?

 

That's unfortunate but the Ecm 12z is colder than the 00z for most of the uk.

The Gem 12z is worth another look, reminds me a little of the famous January 1987 for a while..we coldies can dream can't we?..it's going to turn colder next week, hopefully much colder!

Edited February 3, 2017 by Frosty.