Model Output Discussion

[TEITS]

Dave, re timescale, what one are you referring to for clarity. I am aiming for beginning of Feb,

BFTP

Around the same period Fred +240 (1st Feb).

At the moment I just can't see any notable blocking developing to our NW around this period. If anything I see the reverse with low heights and a well developed PV centred around Greenland. If the SSW does weaken the PV then I can't see this having any effect until the latter half of Feb.

Based on the models so far my interpretation of the next 2 weeks is as follows and it disagrees with the Met O I hasten to add!

I fully expect the UKMO/GEM to back the GFS/ECM wrt to the E,ly. Beyond and turning briefly milder middle of next week before it turns colder once again from the N. However the N,ly is likely to be a weak affair with a 48hr spell of N,lys before the N,ly flow topples. Beyond the N,ly likely to see a spell of mild SW/W,lys.

[Frosty.]

Latest meto update is definately not following the gfs 00z or 06z, more likely the ukmo or ecm or perhaps even the gem model but not the gfs. I'm not sure what the meto do when they construct their update but it appears they are going with a wintry outlook and below average temps which is good enough for me. Even some significant windchill at times..very nice.

Edited January 22, 2010 by Frosty039

[Snowyowl9]

Just looking at GFS normally if a low was heading this way like that it would downgrade it nearer the time,so in this case allow the high to go further north,still cold in the CET zone.

http://91.121.93.17/pics/Rtavn1201.png

http://91.121.93.17/pics/Rtavn12017.png

[karyo]

Latest meto update is definately not following the gfs 00z or 06z, more likely the ukmo or ecm or perhaps even the gem model but not the gfs. I'm not sure what the meto do when they construct their update but it appears they are going with a wintry outlook and below average temps which is good enough for me. Even some significant windchill at times..very nice.

Yes, a really nice update today. They must be expecting the northerly to come off, so that's good news!

Hopefully, we should see all the models come on board in the next couple of days.

Karyo

[ghrud]

Latest meto update is definately not following the gfs 00z or 06z, more likely the ukmo or ecm or perhaps even the gem model but not the gfs. I'm not sure what the meto do when they construct their update but it appears they are going with a wintry outlook and below average temps which is good enough for me. Even some significant windchill at times..very nice.

When it comes down to it computer models are just a tool. There always has be to someone human at the end. For now anyway So lets hope the humans are right.

[Steve Edgefield]

Yes, a really nice update today. They must be expecting the northerly to come off, so that's good news!

Hopefully, we should see all the models come on board in the next couple of days.

Karyo

Agree a positive update for wintriness but I have to say I think the MetO updates tend to change as frequently as the Models. They haven't issued a low confidence disclaimer on this update though so perhaps that's a good sign.

[karyo]

Agree a positive update for wintriness but I have to say I think the MetO updates tend to change as frequently as the Models. They haven't issued a low confidence disclaimer on this update though so perhaps that's a good sign.

That's a good point Steve, they had that disclaimer for the last 3 days or so!

Edit: The MJO continues to progress towards phase 7 http://cawcr.gov.au/bmrc/clfor/cfstaff/matw/maproom/RMM/phase.Last40days.gif

Karyo

Edited January 22, 2010 by karyo

[SP1986]

True!!!! Antway METO have now jumped on the band wagon and has gone for another cold outbreak after next wednesday certainly alot more in store this winter.

It depends what the UKMO are defining as a wintry spell. Many people will now assume a wintry spell will be as harsh as the period of winter we had recently. In reality the UKMO might just be talking of clear days with light frosts at night, even the GFS shows this for a time, with it's more mobile outlook.

Still no offence to the Met-office but if the models as a collective are struggling then in essence the Metoffice have as much chance as you would with 'guesswork'.

Besides Ive seen the Met-office balls up extended outlooks many times before.. I'd personally stick to hoping the models fine some common ground.

[Methuselah]

Pete

Its not just about sunspots. the magnetic field is weakening, the longer term cycle is driving the jetstream south and the magnetic particle interference with the atmosphere affects ozone build up etc etc not suitable for this thread indepth. The main thrust of all this is the jetstream moving south [for me perturbation cycle equates to -ve NAO phase equates to jet forced south.

Dave, re timescale, what one are you referring to for clarity. I am aiming for beginning of Feb,

BFTP

Cheers Fred!

How does the a weakening Solar (?) magnetic field cause the Jet Stream to move further South, exactly??? Will the Beauly-Denny o/head powerlines keep the JS South of Scotland in future years?

[nick sussex]

Well obviously the UKMO expect the pattern to amplify more upstream and this is the reason for their colder than expected further outlook.Perhaps the other models are underestimating the effects of the MJO which may well support a block further north than is shown by the gfs and even the ecm.If you go with the trend of the winter so far then the UKMO looks like it could be onto something. As for the gfs it started its backtrack on the 06hrs run and I expect this to move towards an even more amplfified solution this evening.

As I posted earlier the upstream patten in the USA in terms of NOAA thoughts are this morning for later next week a combination of the ECM and GEM, the GFS has not been used.

[kold weather]

I don't anything too impressive on the models at the moment, the evolution progged now for next week is nearly exactly a middle ground between both the GFS and the ECM evolutions that have been progged for the last week.

I suspect we will get something of a northerly however like others have said it could end up being rather weak, it all depends on just how much of PV lobe we can get over Scandinavia and whether the other vortex is far enough west to allow at least some modest pressure rises over Greenland. Either way it screams toppler flow to me though I don't think it'll be nearly as progressive as the GFS expects, perhaps this will be a more standard cold snap...

After that I wouldn't like to call it to be honest!

[nick sussex]

I don't anything too impressive on the models at the moment, the evolution progged now for next week is nearly exactly a middle ground between both the GFS and the ECM evolutions that have been progged for the last week.

I suspect we will get something of a northerly however like others have said it could end up being rather weak, it all depends on just how much of PV lobe we can get over Scandinavia and whether the other vortex is far enough west to allow at least some modest pressure rises over Greenland. Either way it screams toppler flow to me though I don't think it'll be nearly as progressive as the GFS expects, perhaps this will be a more standard cold snap...

After that I wouldn't like to call it to be honest!

I think even if it topples its unlikely to be the typical return to sw'erlies, i think the jet angled nw/se seems plausible to me given the expected amplified upstream pattern. The EPO is well into negative territory and supports west USA ridge and troughing over the eastern USA, the orientation of the trough IMO is uncertain though so this might be causing the model divergence.

http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.we.png

[kold weather]

The problem is Nick if we end up with the PV over Greenland (which IMO is very possible for the first 2 weeks of Feb) then it will dominate our weather no matter how good upstream patterns may become. Still there is uncertainty about even that yet to not be too bothered about it.

[nick sussex]

The problem is Nick if we end up with the PV over Greenland (which IMO is very possible for the first 2 weeks of Feb) then it will dominate our weather no matter how good upstream patterns may become. Still there is uncertainty about even that yet to not be too bothered about it.

Well i think its unlikely the PV will limpet itself to Greenland and this would go against the expected pattern by NOAA on last nights discussions. I can't see that much has changed overnight and it would tie in with the EPO forecast west USA ridge, trough over east USA and North Atlantic high, this is what they're going with.

Considering what the model output showed a few days ago I'm feeling quite positive about things for the next 10 days, to be honest if we can end January on a cold note and start February the same then if lets say it does turn milder, then its still been a good winter.

[dallas]

Well i think its unlikely the PV will limpet itself to Greenland and this would go against the expected pattern by NOAA on last nights discussions. I can't see that much has changed overnight and it would tie in with the EPO forecast west USA ridge, trough over east USA and North Atlantic high, this is what they're going with.

Considering what the model output showed a few days ago I'm feeling quite positive about things for the next 10 days, to be honest if we can end January on a cold note and start February the same then if lets say it does turn milder, then its still been a good winter.

I hope your positive outlook comes to fruition Nick, would seem strange to have a mild Feb after the recent cold weather, I wonder if there will be a short period of wet milder weather though, at least until we see the PV start to bed itself in over our side

[Frosty.]

As I posted earlier the upstream patten in the USA in terms of NOAA thoughts are this morning for later next week a combination of the ECM and GEM, the GFS has not been used.

I hope they have used plenty of the GEM in their thoughts, a truly stunning run for coldies with a N'ly blast such as we haven't even seen this winter so far, it's all been about E'lies so far but maybe it will be the turn of the north soon but not if the gfs has anything to do about it, i'm wishing for the gfs to fall in line on 12z but it probably won't.

[BLAST FROM THE PAST]

Cheers Fred!

How does the a weakening Solar (?) magnetic field cause the Jet Stream to move further South, exactly??? Will the Beauly-Denny o/head powerlines keep the JS South of Scotland in future years?

It has an affect on the pressure belts on the planet. Last 200 years has seen the ITCZ expand [fatten] and thus the jetstream moved north [it has been recorded as moving north upto 2002.] We are now in longterm reversal [and this is where IMO GWO has cottoned onto something with his PFM theory]. It works in conjunction with lunar phases and the planetary magentic field impacts on Earth [RJS theory]. This one of the reasons why I called against IB last year and this year re the MW theory being irreversible and down to AGW. Surely the last 3 years of the jetstream track has made folk sit up and look, and this year even with an El Nino in place. Off topic but just a quickie reply to Pete.

Dave [TEITS] ta, so same timescale then....no to strong northern arm IMO in Feb, jet to kick south.

BFTP

Edited January 22, 2010 by BLAST FROM THE PAST

[johnholmes]

hi all

from sunny snow covered Wengen

just keeping an eye on teleconnections and to me a number are starting to look positive for the coldies amonsgt you.

even the 30mb temp is on the rise-the AO, NAO and PNA are not totally on side but may be thinking about it it seems to me.

the 500mb NOAA anomaly charts along with the EC version, GFS not quite so far onside, all suggest the omega pattern is about to set up and in the right place for cold air-so I reckon it will be a cold UK when I get back 31 Jan not a mild one+

tara

[snowray]

Afternoon everyone.

Only got back to the UK this monday having been away around Europe for 4 weeks and I was amazed how consistent UKMO was as compared to the other models, frankly it was spot on most of the time within the +T74 period, particularly with their PPN forecasts, GFS was wrong quite often even at +T12 timeframe when it came to the finer detail, which for the GFS seems to be the mere difference of some 50/100 miles which is quite a distance on the ground but probly nothing on a global scale. We saw this again with this Weds PPN being progged over Cornwall by GFS for a few runs and then hey presto, it pops up over London!

Now UKMO can have its blips of course and nothing is full proof but I'm sticking with this model all the way at least upto T96 or so. The new GFS is great at spotting trends at times, but thats about it because it quite often drops everying just as things get going. When you consider it proposes 4 different possibilities in 24 hours you would expect some consistency.

Snowray

Edited January 22, 2010 by snowray

[nick sussex]

I hope they have used plenty of the GEM in their thoughts, a truly stunning run for coldies with a N'ly blast such as we haven't even seen this winter so far, it's all been about E'lies so far but maybe it will be the turn of the north soon but not if the gfs has anything to do about it, i'm wishing for the gfs to fall in line on 12z but it probably won't.

That was on the early morning update they have since included some of the gfs together with the ecm but overall the upstream pattern does look favourable for a return to colder conditions.Whatever happens we're likely to see out January on a cold note, as for into February too early to say but I think at least the start will be cold.

[Airedalejoe]

Lunch time weather on BBC had it turning colder next week and by wednesday temperatures struggling to get above freezing point in what looked like an easterly flow...certainly different to the 06z GFS, lets hope the 12z comes on board.

[jy]

According to the weather forecast at 1 25 on bbc they showed Easterly winds,quite strong at that too,with temperatures quote struggling to get much above freezing unquote by midweek.The reason this is in the the model thread is what model do they use,because reading many posts on here,little similar comment has been made,again an education thing for me,would welcome any advice.

[Iceberg]

An infrequent post from me, I very much agree with John, It's still looking good for a return to cold come the change of the month.

The models shifted quite dramatically to the shifting of the PV from Eastern Siberia across into Greenland.

This is a very unusual and quick shift of the PV and it's noticable that the models today having been retreating from that idea.

Looks like an over-reaction to a medium range factor such as MJO or dateline convection to me.

A shift westwards of the PV is however likely and my guess is that the models will show this shift more and more to the Scnady region allow pressure rises more towards Greenland as shown by ECM 00Z.

The 12's should support this as well to me.

[snowmadchrisuk]

Lunch time weather on BBC had it turning colder next week and by wednesday temperatures struggling to get above freezing point in what looked like an easterly flow...certainly different to the 06z GFS, lets hope the 12z comes on board.

The 12z hasn't come on board , Infact it is milder than the 6z was for next week , Tuesday has +5 850's and high pressure splap bang on top of us . Surface flow looks like it may be cooler but nothing wintry from the 12z really at all out to the middle of next week.

[Iceberg]

The 12Z is a stunning run at 138 and shows the PV slipping into Scandy and the High Iceland way.

Good ECM agreement