Model output discussion - 21st Jan Onwards

[legritter]

10 minutes ago, BLAST FROM THE PAST said:

06z looks like more cold air involved. Lots of tweaking to come me thinks. 

 

BFTP

yes i,m very impressed with current charts ans data ,just getting the dice to fall right i think depending on your location ,liking that at long last some arctic air is modelled to come further south and some hopefully weather systems around for some fun and games tonights runs eagerly awaited to see i hope some firming up ,Bap and coffee  cheers gang .

[mb018538]

In the mid term, the models are strongly hinting at a major storm system blowing up Thursday into Saturday.

On Thursday, it's a small low of 990mb....by the same time Friday it has dropped to 965mb....so technically a bomb, before another low is absorbe into the circulation Saturday, and it deepens to 960mb.

When you see this jet stream, with a nice trough in to aid cyclogenesis, it's not surprising. Could be the next named storm system for sure.

[fergieweather]

29 minutes ago, BLAST FROM THE PAST said:

06z looks like more cold air involved. Lots of tweaking to come me thinks. 

 

BFTP

Indeed so. As I mentioned yesterday, we must expect a raft of model outcomes as suites get to grips (or mostly not, currently) with broadscale pattern change and drivers next month. Many should recall the similar wild fluxes we saw ahead of last key pattern change earlier this month (to the colder blocking) albeit for different reasons. The prognosis for Feb was discussed last week at Exeter (seasonal outlook meeting, held monthly) and since then, there's been no strong reason to shift from the views I outlined yesterday re anticipated changes especially from mid-month (when SSW influence likely to be coming into play). 

[feb1991blizzard]

4 minutes ago, fergieweather said:

Indeed so. As I mentioned yesterday, we must expect a raft of model outcomes as suites get to grips (or mostly not, currently) with broadscale pattern change and drivers next month. Many should recall the similar wild fluxes we saw ahead of last key pattern change earlier this month (to the colder blocking) albeit for different reasons. The prognosis for Feb was discussed last week at Exeter (seasonal outlook meeting, held monthly) and since then, there's been no strong reason to shift from the views I outlined yesterday re anticipated changes especially from mid-month (when SSW influence likely to be coming into play). 

Any support for the split SSW evolution on in house models yet? that would really put the cat amongst the pigeons wrt a very cold late winter / early spring I would think.

[festivalking]

Just now, feb1991blizzard said:

Any support for the split SSW evolution on in house models yet? that would really put the cat amongst the pigeons wrt a very cold late winter / early spring I would think.

Based on the information from fergie regarding the SSW the odds on a white easter must be shortening.

[feb1991blizzard]

1 minute ago, festivalking said:

Based on the information from fergie regarding the SSW the odds on a white easter must be shortening.

Lets hope we get something before then though.

[Connor Bailey Degnan]

Yes, rain and wind does look likely to feature quite a lot in the next week or two, but strong signals are there now for the jet to dive south from around the 11th and allow a colder North-westerly to Northerly to develop, enhancing the risk of snow events across more northern areas of the United Kingdom. However, I certainly wouldn't rule out parts of the south seeing some snowfall later on in February. I feel the Strat warming will almost definitely come into place now from around the second week of Feb!

[Frosty.]

Hot off the press...Much better news regarding second half of Feb with a change from the relatively mild swly to wly flow veering more nly to nwly with colder and brighter conditions bringing widespread frosts and snow showers for some of us, especially for areas more exposed to winds from the Arctic, something similar to what the Gfs 6z op run shows!

[fergieweather]

21 minutes ago, Frosty. said:

Hot off the press...Much better news regarding second half of Feb with a change from the relatively mild swly to wly flow veering more nly to nwly with colder and brighter conditions bringing widespread frosts and snow showers for some of us, especially for areas more exposed to winds from the Arctic, something similar to what the Gfs 6z op run shows!

Caution though (I assume you refer to the overnight UKMO web update?): we've yet to see any strong signal for temperature anomalies dropping well below average in the longer-range products. At present, and in the absence of any compelling pointer otherwise, the outlook is thus worded appropriately to reflect yesterday's GloSea & ECMWF output, i.e.  to lean towards "slightly below average" later in February. 

This emphasis may, of course, change in due course.

Edited January 29, 2016 by fergieweather

[Purga]

4 minutes ago, fergieweather said:

Caution though (I assume you refer to the overnight UKMO web update?): we've yet to see any strong signal for temperature anomalies dropping well below average in the longer-range products. At present, and in the absence of any compelling pointer otherwise, the outlook is thus worded appropriately to reflect yesterday's GloSea & ECMWF output, i.e.  to lean towards "slightly below average" later in February. 

This emphasis may, of course, change in due course.

"This emphasis may, of course, change in due course."

Let's hope so Ian - and in the 'right' direction!

The GEFS are creeping down but nothing dramatic

Maybe we will get a Buchan cold snap?

[Frosty.]

16 minutes ago, fergieweather said:

Caution though (I assume you refer to the overnight UKMO web update?):

Yes it's based on the latest update which struck me as being much better than yesterday and probably one of the most positive for coldies so far this winter but I appreciate it's not in the bag, however, it's very encouraging.

[MR EXTREMES]

3 hours ago, Frosty. said:

The Gfs 6z saves the best until last with a colder and more blocked pattern...and some snow too!

this most certainly a nice wintry chart frosty ,

 but I feel the block itself is a feeble attempt but certainly would love to see this trend continue with any residual energy from the Canadian vortex to go under the block,

still its only one run and the last week or so we have seen blocking popping up from time to time,

but the last 24 36 hrs model watch have seen a decline in blocking until now lets hope the 12z 18z 6z from the big models showing more of the same.

but this is the trend I'm looking for although that's because I'm a selfish southerner lol

and many thanks to gibby for his insight very greatful.

Edited January 29, 2016 by emotional rollercoaster

[Mucka]

3 hours ago, fergieweather said:

Indeed so. As I mentioned yesterday, we must expect a raft of model outcomes as suites get to grips (or mostly not, currently) with broadscale pattern change and drivers next month. Many should recall the similar wild fluxes we saw ahead of last key pattern change earlier this month (to the colder blocking) albeit for different reasons. The prognosis for Feb was discussed last week at Exeter (seasonal outlook meeting, held monthly) and since then, there's been no strong reason to shift from the views I outlined yesterday re anticipated changes especially from mid-month (when SSW influence likely to be coming into play). 

Hi Fergie,

I wonder why then the 30 day forecast changed from NW type from mid month via Atlantic ridge to NW flow type late month via Atlantic ridge?

that seems like an obvious and deliberate change to the forecast for Feb to me.

The very latest update has gone back to a mid month pattern change.

I assume this was due to the signal waning for a time but now restrengthening for a mid month pattern change?

[IDO]

ECM week 4 anomaly looks much like the other LR models:

 

 

[Methuselah]

Ah, that's better!

Anyways, the GFS 12Z is about to start dribbling...Will it be screaming potential, re-introducing the blowtorch, or will it have the MetO's winter-forecast within its sights? Who knows?

Just keep it polite, eh?

[phil nw.]

Re.The possible mid-Feb north westerly.There is a signal now starting to show for mid-Atlantic +ve heights in the gefs

  

which seems to peak around days 11/14.

Early days yet and time will tell if this will give us a true Arctic feed but something to follow in the coming days

 

[Daniel*]

Severe storm for Scotland on Monday the storm is further S and deeper. 

Edited January 29, 2016 by Daniel*

[feb1991blizzard]

15 minutes ago, Daniel* said:

Severe storm for Scotland on Monday the storm is further S and deeper. 

That's good news then, the further S it tracks, the further S any cold air following on behind will get./

[That ECM]

Going to be interesting to see fi in this run with pressure building NE. Low heading into Europe?

Edited January 29, 2016 by That ECM

[Daniel*]

A lot more amplified upstream here a pinch going on, has the shape of a butterfly rather than the squashed type 6z was showing enough for a clean northerly.

 I'm surprised little discussion is going on. 

Edited January 29, 2016 by Daniel*

[Connor Bailey Degnan]

Another Good GFS update. Personally think we could see something wintry in March as well now. Before then i'm sticking with my prediction of a cold and snowy outbreak between 11-18th February before the Atlantic pushes back in with a milder south westerly setting up.

[feb1991blizzard]

19 minutes ago, Daniel* said:

A lot more amplified upstream here a pinch going on, has the shape of a butterfly rather than the squashed type 6z was showing enough for a clean northerly.

 I'm surprised little discussion is going on. 

Yes, I agree, a very good 0z onwards if your looking for colder weather later on in February, barring the very end of the EC32 where it flattens out again, I just wonder if its fatigue, or the view from Southern / S Eastern members that because of sun strength that its too late to deliver (there are a lot of NW members in the SE), or people thinking its just another lead up the garden path again.

[stainesbloke]

3 minutes ago, feb1991blizzard said:

Yes, I agree, a very good 0z onwards if your looking for colder weather later on in February, barring the very end of the EC32 where it flattens out again, I just wonder if its fatigue, or the view from Southern / S Eastern members that because of sun strength that its too late to deliver (there are a lot of NW members in the SE), or people thinking its just another lead up the garden path again.

It does look better for cold, based on the latest model output. I don't think 'sun strength' is a major issue in Feb even in the south. If the air is cold enough then it won't matter. It's probably model fatigue and people being rightly cautious. If charts are still showing cold at T96 then it'll be a different story no doubt.

[feb1991blizzard]

Just now, stainesbloke said:

It does look better for cold, based on the latest model output. I don't think 'sun strength' is a major issue in Feb even in the south. If the air is cold enough then it won't matter. It's probably model fatigue and people being rightly cautious. If charts are still showing cold at T96 then it'll be a different story no doubt.

Yes, I agree, It does eventually become a problem but usually only with showers, even in March, if you get big thick flakes via a slow moving system  and good PPN intensity, theres no problem with it sticking.

[nick sussex]

Only just catching up with todays outputs and generally good agreement for the overall pattern.

However the detail which is all important shows some differences with the PV lobe over Canada.

The UKMO T144hrs has this lobe much further west compared to the GFS 12hrs run and has a stronger Arctic high, it could develop more favourably going forward.

The UKMO looks like it runs a shortwave ese into the UK between T96 and T120hrs so something to look out for, a chance of some snow off that although the track might change which will effect which areas could be effected.

Edited January 29, 2016 by nick sussex