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

[Weathizard]

3 minutes ago, Johnp said:

Awful chart according to Weathizard!

Oh please it's a 240 chart, I'm talking about the evolution from 96-144hrs.

[Ali1977]

7 minutes ago, Ed Stone said:

But nothing that you or I, or pros or models say can have any effect on the weather...

I'm not sure what you are saying, all I said was that "maybe the GFS is quite accurate with it's forcast".   What on earth does that have to do with me casting spells on the weather  - are you suggesting I said im Gandalf or something!!!

Ian F said the UKMO GM is less bullish on the cold, just like the latest GFS run - I just pointed out that the GFS maybe quite accurate with what Ian is saying..."MAYBE" being the key word...

Edited February 6, 2017 by Ali1977

[MidnightSnow]

Just now, Ali1977 said:

I'm not sure what you are saying, all I said was that "maybe the GFS is quite accurate with it's forcast".   What on earth dopes that have to do with me casting spells on the weather  - are you suggesting I said im Gandalf or something!!!

The reading comprehension can be pretty poor at times lol..

[Ice Day]

FInishing off with some FI fun.  Another easterly incoming

[MKN]

I think to save arguments its quite clear the models haven't got a firm grip on details for the weekend yet we may have to wait until tomorrow or weds. Perhaps a bit of snow on Wednesday to look forward to prior to that anyway.

[Lampostwatcher]

isnt ian talking about the SW

[Kentish Snowman in Yorks]

So in summary following the GFS and UKMO 12z runs this afternoon what have we learnt?

It's getting colder and it might snow! 

[MattTarrant]

Haha perhaps but unlikely, whatever the 12z chart is showing, it is the trends we should be looking for. Such as slight movement south of the High/More energy going North/Low Dropping towards Iberia is less developed/WAA and such things...

[Frosty.]

I'm just waiting for Steve Murr to call us all lemmings

Fact..it's about to turn much colder from the east with high wind chill, ice days and frosty nights with an increasing chance of snow flurries / snow showers spreading inland from the north sea..that's well within the reliable timeframe.

[Downpour]

Just now, Lamposangel delightcher said:

isnt ian talking about the SW

Yes. The upgrade/downgrade malarky would rather depend on where you are. For example, GFS is arguably an upgrade for London/SE as it calls for snow showers in the (semi)reliable. 

[Woldsedge]

There seems to be some major spitting dummies out of prams on here, over what is just a few minor adjustments. Just look at the overall picture instead of dissecting every single run. #peacetoallmen

[Daniel*]

15 minutes ago, northwestsnow said:

Not saying the 12zs are correct, just saying they are a downgrade, esp the ukmo run from this morning, as ian fergie says, its removed the cold pool.Anyway, lets see what ecm says..

He does not state that. 

Cold pool visible to SE England coming in from Benelux. Some snow too I'd think.

Edited February 6, 2017 by Daniel*

[nick sussex]

Regarding the flattening of the Scandi high, this is unavoidable because the PV wants to move east/ne towards Siberia. However theres a big difference between a flattening and a sinking without trace.

If theres a signal to retrogress you always get some sinking before you get another pressure rise to the north and you hope that a chunk of the PV can get sw as that happens.

 

[Methuselah]

8 minutes ago, Ali1977 said:

I'm not sure what you are saying, all I said was that "maybe the GFS is quite accurate with it's forcast".   What on earth does that have to do with me casting spells on the weather  - are you suggesting I said im Gandalf or something!!!

Ian F said the UKMO GM is less bullish on the cold, just like the latest GFS run - I just pointed out that the GFS maybe quite accurate with what Ian is saying..."MAYBE" being the key word...

I just wanted know how the GFS is 'looking quite accurate', that's all?

[AmershamMike]

I'm waiting for Steve M's take on things - waaaay too much hair splitting and petty bickering going on to make head or tail of all this!

[markw2680]

25 minutes ago, northwestsnow said:

Well gfs12z has temps at night above zero by sat night for many so compared to the 6z ? If thats not a pretty big downgrade i dont know what is..added to that temps of 4 and 5 widely through saturday..

It's 5 days away, common we all no its going to change for better or worse before then. Trends not Gospel 

[East_England_Stormchaser91]

18 minutes ago, Weathizard said:

The 12z GEM isn't good, far from it IMO! 

Unless I'm missing something, the 12z latest GEM has sub -8 uppers never leaving the east coast, and then ejects a shortwave containing -20 uppers out of Russia heading straight en route to us! Think you may have been referring to the 00z GEM this morning? 

[Seasonality]

Just now, East_England_Stormchaser91 said:

Unless I'm missing something, the 12z latest GEM has sub -8 uppers never leaving the east coast, and then ejects a shortwave containing -20 uppers out of Russia heading straight en route to us! Think you may have been referring to the 00z GEM this morning? 

Lol. GEM does indeed vomit forth a searing blast of cold.

[nick sussex]

With Scandi highs theres not an endless supply of cold to draw on, you have to have some sinking with energy running over the top and south as the pattern retrogresses to inject some more cold into the circulation. You'll see that's what the GFS does, what we're hoping to see is a bit more jet cut back with catching a lobe of the PV to be pulled sw'wards.

In situations where the Atlantic is going to win you get sinking without trace because theres no signal to retrogress the pattern but we're not seeing that here because the MJO is providing that retrogression signal.

[Weathizard]

3 minutes ago, East_England_Stormchaser91 said:

Unless I'm missing something, the 12z latest GEM has sub -8 uppers never leaving the east coast, and then ejects a shortwave containing -20 uppers out of Russia heading straight en route to us! Think you may have been referring to the 00z GEM this morning? 

Oops yes, apologies I had the wrong toggle on. 12z is much better, high pressure pretty close throughout thou

[karyo]

The 12z gfs offers a very different stratospheric picture compared to the previous runs. It moves the vortex to Siberia rather than split it.

[Nouska]

Surely Ian Fergusson is talking about the upper cold pool needed for instability for convective shower development. That has certainly been reduced and moved south in comparison to the midnight run.

00Z     12Z

Fiddling with reverse on the ARPEGE.

http://www.meteociel.fr/modeles/arpegee_cartes.php

There's enough dubiety and options to make dissection useless at this point in time.

Edited February 6, 2017 by Nouska

[Paul]

Just a quick one, following on from feedback, we've started an in depth/chilled out model thread. So if those who want to make more in depth posts, in a slower paced thread want to use that it's available - it's also fine to cross-post any in depth stuff into both that and this thread if anyone wants to do that too. 

 

[winterof79]

Well I had to look for myself regarding the weekend blow torch

And sure enough there is no cold pool by weekend in East Africa

[nick sussex]

1 minute ago, fat chad said:

Thank you nick... Finally some sanity in here this afternoon.

You're welcome. Although I think sanity might be pushing it with me! lol Everyone knows I'm not slow in throwing my toys out of the pram if I think the situation warrants it however I see nothing to be worried about. No sign at all of the Atlantic winning this battle and with the MJO on side  the models are trying to work out how to retrogress the pattern.