Model Output Discussion

[MR EXTREMES]

GFS likes the idea UKMO fax doesn't show the cold getting so far west so that would fit in with the downgrade to the warnings. Tis a bit messy at the moment.

downgrades there was no upgrade it was just an advisory.

the block to our east will have limited effect on our weather with the alantic still making inroads.

there is very little from the models tonight and as has been said its messy.

im glad im not building my hopes on cold prolonged blasts from the east its not likely.

looks like gp is spot on but then again id expect nothing less from somebody with such excellent gift of reading teleconnections.:o

[The PIT]

I have no idea how you arrive at that comment from my post. GP is a weather god and is the best medium range forecaster on this or any other site in my view.

My point was otherwise and I suggest your read it again, and this is not a standard zonal jet profile at the end of the run..

http://209.197.11.109/c9s4a5k3/cds/gfsimages/gfs.20100118/12/384/hgt300.png?dopvhost=charts.netweather.tv&doppl=841a626ccf4efe59cf1efe091edbf542cf1efec3&dopsig=a01eafa4af1b612cf4c0aea3641f0c46

Nope you didn't say that and read my original post again. Virtual glasses on the way. Doh.

Anyway I'm waiting for ECM as I don't believe this GFS run anyway as it's quite a sudden switch.

Okay I was referring to advisories badboy and I just found it amusing when there wasn't anything showing in the uppers for a massive dumping they downgrade it and up pops the GFS saying come on upgrade the advisories.

Edited January 18, 2010 by The PIT

[Matty M]

I am of the personal opinion that this is FI

I await with great interest the model outputs in the coming days.

I think some major short term changes could occur.

[TEITS]

At the moment based on all the runs I have seen and also using a bit of instinct I would suggest the following.

Into the beginning of next week we're likely to see the HP to our S merge with the block to the NE bringing a fairly slack E,ly flow.

http://www.wetterzentrale.de/pics/Rukm1441.gif

http://www.wetterzentrale.de/pics/Rgme1321.gif

24hrs earlier than I thought.

Utter confusion in the model output at the moment with the block much stronger than initially progged.This what myself and a few others have been saying for a while.

Im sure I read someone saying there isn't any model uncertainity. Well the 0Z GFS had -12C upper temps 30 miles off tne Norfolk coast at +168. The 12Z GFS have this all the way back to Finland! Now that is what I call model uncertainity!!

I will add that the snow event on Wed its being pushed back further W with each run. At this rate the precip won't even reach the W!

Edited January 18, 2010 by THE EYE IN THE SKY

[grab my graupel]

I am of the personal opinion that this is FI

I await with great interest the model outputs in the coming days.

I think some major short term changes could occur.

Tend to agree there, Matty. There's not much point looking beyond that stage until we

reach some kind of Model consistency.

I have to say, though, it's fascinating model watching

[Cheese Rice]

I don't know why there are some negtive comments on here, the models have vastly improved on what was shown a few days ago. Yes FI isn't looking brill but thats why it is FI.

[Severe Siberian icy blast]

I get the impression ones are very fustrated on hear , but i dont see much to be disapointed about really , this event wed i do see happening , the bbc and met mentioned it days ago and hasnt downgraded anythin , i always knew it would be wet snow , and marginal , we'r not sat in cold dry continental air like we was 2wks ago , aso in our world the best snow events come from wet marginal events

As for f1 , its only this one run thats not s cold , but to me still looks to have cold snaps with very cold air always near by .

As for the scandi high , its very strong and very potent and just cause the models are showing atlantic dominance it means nothing at all and will give us influence from time to time opening the door to more marginal snow events.

[D KARLSON]

IMO the models over the last week have never had a handle on the block. The models use previous data / experience and default to zonal but this isn't your average block! I would love to see continuous repeats of this weds scenario and this is still possible! See below for NAE precipitype which upgrades snow on Weds for central southern parts.

http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/01/18/basis12/ukuk/prty/10012012_1812.gif

Easterly from UKMO - http://www.meteociel.fr/ukmo/run/UW144-21.GIF

GFS 12z ending in a Euro high (won't say the B word!)

All in all who knows?! Meto don't thats why they are being so vague!

Your right about that and certainly a few surprises in store as the models try to factor a normal blocking sc enario against this once in 30 year block and it is that rare; temps over russia scandinavia and most of europe have not budged for weeks locked in a deep freeze and that cold air simply cant be dislodged by the atlantic.

some fun a games to come with this and its more fun when the so called proffessionals cant nail it

[Ben_Cambs]

IMO the models are just too messy past T+96 to rule out anything. The models are chopping all over the place, with very cold in some runs and very mild in others. So dont rule anything out at the moment!

[SnOwFeSt]

I think FI is out at about t+36 at the moment. GFS really struggling with how far the low pressure will push east. Imo it is being over progressive, and the low will either stall or move northwards, keeping us in the relatively cold air (progged for late wed/ early thurs) for longer. The trend has been for the atlantic to be pushed further west, and I can see this continuing over the next few runs

Also a chance we could tap into the cold air in scandanavia over the weekend imo bringing cool, clear conditions

[weather eater]

IMO the models over the last week have never had a handle on the block. The models use previous data / experience and default to zonal but this isn't your average block! I would love to see continuous repeats of this weds scenario and this is still possible! See below for NAE precipitype which upgrades snow on Weds for central southern parts.

http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/01/18/basis12/ukuk/prty/10012012_1812.gif

Easterly from UKMO - http://www.meteociel.fr/ukmo/run/UW144-21.GIF

GFS 12z ending in a Euro high (won't say the B word!)

All in all who knows?! Meto don't thats why they are being so vague!

1st point the models do not use previous data/experience, there are guides on the NW site that explain how they work

2nd point where is this model uncertainty, the UKMO looks pretty similar to the GFS at 120hrs and the GFS has been consistent for that time period for quite a few runs now

3rd point I don't think the block is any more likely to effect us now than it did a couple of days ago.

[Michael Fishermans Friend]

TheGFS looks to be all over the place at the moment! - what ever happenend to the influence of the Siberian/Scandy high that it showed for quite a few runs a couple of days ago, it now seems to have vanished. So far this winter the GFS has performed very poorly and I really take evrything it shows outide +72/96HRS with a large pinch of salt!

[LomondSnowstorm]

Models are all over the place. I think anyone would be a fool to call a mild spell for late month after the UKMO 144 hour chart and a fairly cold ECM this morning. People are straw-clutching and looking into FI for the usual atlantic driven weather, when in reality we just don't know beyond about 96 hours, even 24 hours out before 850hpa temperatures are very accurate.

LS

[Frosty.]

The interesting model output continues with a surprisingly good ukmo 12z which shows the siberian/scandi high fighting back even by sunday and the start of next week which is a huge change from the 00z which showed a sw'ly across the BI although it could easily flip back again, very small changes can make a big difference in the overall picture. The GFS 12z is another fairly cool run with a milder section mid way through followed by an arctic plunge which just keeps showing towards the end of the month but we end up with a euro high developing by the end of the run.

Edited January 18, 2010 by Frosty039

[LomondSnowstorm]

1st point the models do not use previous data/experience, there are guides on the NW site that explain how they work

2nd point where is this model uncertainty, the UKMO looks pretty similar to the GFS at 120hrs and the GFS has been consistent for that time period for quite a few runs now

3rd point I don't think the block is any more likely to effect us now than it did a couple of days ago.

The UKMO 144 hour chart http://www.wetterzentrale.de/pics/Rukm1441.gif

GFS 144 hour chart http://www.wetterzentrale.de/pics/Rtavn1441.png

The UKMO has everything a few hundred miles further west than the GFS.

LS

[Eugene]

http://www.wetterzentrale.de/pics/Recm1201.gif- Looking promising.

[Thundery wintry showers]

One consistent trend with recent run is the re-establishment of high pressure around the vicinity of the British Isles during the coming weekend. The type of weather that results will depend on where the high ends up. Chances of a cold snap as a result, though some ECM and GFS runs suggested an easterly for this week that isn't set to come off (apart from a brief flirtation around Wednesday) so any apparent latching onto a cold trend should still be treated with caution at this early stage.

[Matty M]

Synoptically messy 144hrs ECM.

very cold shot in southeastern Europe, far southeaster.

Signs of pressure rising to our north with heights increasing.

[weather eater]

The UKMO 144 hour chart http://www.wetterzentrale.de/pics/Rukm1441.gif

GFS 144 hour chart http://www.wetterzentrale.de/pics/Rtavn1441.png

The UKMO has everything a few hundred miles further west than the GFS.

LS

I've seen them already. Small details will change on model runs in the near time scale, this can make a difference to us living on a small island, but this happens every run, every day every model and thus statements like the models are all over the place are just nonsense as they are no more, all over the place than at any other time. The general pattern out to 120hrs remains pretty much the same as it was. Out past that 120hrs that would be a fair comment as the models really cannot pick a trend at the moment for the post mid-range period.

Edited January 18, 2010 by weather eater

[PB22]

Interesting model output this evening - it looks to me that the models are currently in the process of picking up on new developments in the outlook, hence the rather confusing picture being painted by the models at the moment. The ECM T+144 sums things up well at the moment IMO:

[NorthantsSnow]

The ECM at T144 is among the most bizarre charts I've ever seen.

At T168 the track of that LOW just SW of Greenland is going to largely dictate where we go from here IMO.

[Tom D]

GFS looks like it's on its own with keeping the high further south of the UK this weekend, with the UKMO, GEM and ECM all looking to push it further north, giving us settled conditions rather than the nasty westerly flow the GFS operational and control give.

It's not set in stone but the majority of outputs this evening give us a settled spell of weather next week - it wouldn't be possible to say if it would be particularly cold at the moment but it does appear quite dry.

EDIT: ... and then the ECM +192 comes out

Edited January 18, 2010 by Tommyd1258

[Eugene]

http://www.wetterzen...cs/Recm1201.gif- Looking promising.

Not a bad prediction there mate

[bluearmy]

despite the apparent confusion run to run and model to model, there does appear to be an appetite for the p/v to come tumbling in our direction from siberia in the medium term across the output. if we could get the block to either retrogress or sink se, i think we'd be in business. what are the chances though ???

[igloo]

The ECM at T144 is among the most bizarre charts I've ever seen.

At T168 the track of that LOW just SW of Greenland is going to largely dictate where we go from here IMO.

funny looking or not i for one would certainly not complain with this evenings run.it looks more and more likely a further cold snap is on the cards