General Model Output Discussion

[anvilhead]

GFS 12z for cirencester:

Monday Midday: 1c (Winds Easterly)

Tuesday Midday: 1c (Winds SEasterly)

Wednesday Midday: 1c (Winds ESEasterly)

Thursday Midday: 1c (Winds Easterly)

Friday Midday: 0c (Winds Northerly)

Friday Midnight -2c (-10 in wales) (Winds Col)

GFS's been moving towards bringing down temps over the last 3 runs - disrupting the trough and sending a low into the med -

While I dont use the gfs as gospel, and other models right now show more displacement of the high to the east and milder temps moving in, but its not written in stone. I think only a fetch not from the SE will give us any breakdown in the cold right now due to the cold continent- my money is on a disrupting trough, and SE'ly to Easterly throughout next week, although I personaly want an end to this cold!

[J10]

Surprisingly cold uppers with ECM, snow for many seemingly likely if the T+120/T+144 happens, interesting to see where it goes in the longer term.

[Snowly does it]

Surprisingly cold uppers with ECM, snow for many seemingly likely if the T+120/T+144 happens, interesting to see where it goes in the longer term.

By T168 we are in limbo with a ridging Azores (displaced) and a Scandi in place - very similar to the GFS solution actually for me.

[BornFromTheVoid]

The 12Z ensemble mean still showing a slider.

I think it will be closer to sunday before we know what's really going to happen, too much chopping and changing at the moment.

[Iceberg]

Surprisingly cold uppers with ECM, snow for many seemingly likely if the T+120/T+144 happens, interesting to see where it goes in the longer term.

um ECM dumps 1ft of snow and then doesn't really warm up a great deal, however the 72 to 96 evolution is crazy, with far too much southerly Jet interaction with the developing low.

It still doesn't want to gear up the Atlantic though and instead near the end pumps up the pressure to the NE.

[Matty M]

Will be interested to see the ECM ensembles again.

What time they out?

[rich1]

The 12Z ensemble mean still showing a slider.

I think it will be closer to sunday before we know what's really going to happen, too much chopping and changing at the moment.

TBH I think the output is struggling a tad, even the ECM doesnt exactly promote a full blown Atlantic takeover and he uppers still look pretty cold for the most part

breakdown it could be but mild it isnt really, and the evolution looks a bit confused

think there may be a trend for less cold out there but as for how long it lasts, it doesnt look like a return to 'normal' to me

bet had the output been around in 1979 or 1963 there woud have been a few runs like these, as it is there wasnt sub zero temps every day

I would say next week is hugely uncertain, for me I would like the cold to continue but still feel we have done really quite well so far so if we did get a less cold interval it wouldnt be the end of the world, but I think there is a way to go yet before we get a clearer picture as to where the rest of january will go

Edited January 8, 2010 by rich1

[Nick F]

Sometimes we have to except the fact that FI can be rather close, and that looks the case for mid-week next week, with such divergence with what to do with the low to the SW after t+96 - which I think is the limit of reliability atm.

Differences between ECM and UKMO/GFS seem to be that ECM keeps the Atlantic trough intact while the block retreats quickly east over NE Europe - allowing the low to move NE across the UK from Biscay. Whereas UKMO/GFS keep the block firm over Scandi, not really moving, which disrupts the approaching Atlantic trough with a cut-off sfc and upper low ejecting east.

Having said that, as others mention, the uppers are still cold when the low on ECM moves NE over UK, so not a disaster for cold and snow fans and maybe a snow storm likely inland?

FI starts at t+96!!

[Altostratus]

Just as support grew for extending the very cold spell, with additional support for undercutting, the ECM throws a spanner in the works. If the ECM operational isn’t an outlier amongst the ensemble suite, particularly for the early stages of the run, it is possible it could be on to something. It is uncharacteristic of the ECM to be more progressive than the GFS. I feel that the ensembles will be revealing tonight. It is important to bear in mind, even if this ECM run verifies, it will remain on the cold side. Although whether it remains cold enough for snow is a bit dubious.

[igloo]

at least its consistent its looks virtually the same run from 0z its looking more and more likely a breakdown will start by mid next week

[Snowyowl9]

What I don`t don`t understand is this scandi high is only just building/moving today and the models just want to take it so far east/the other day they were toying the scandi high retrogressing westwards again back to greenland.

Anyway this is actually a cold chart and I`ve seen archives like this that can bring something very special.

http://www.wzkarten.de/pics/Recm1921.gif

[Iceberg]

If your idea of a breakdown is lots of snow, fog and frost then ECM is a breakdown. Have to admit it's not my idea of one.

[Snowly does it]

at least its consistent its looks virtually the same run from 0z its looking more and more likely a breakdown will start by mid next week

Not really - whilst each model toys with an Atlantic attack, none of them show the attack succeeding in a change of pattern - it is still cold, the Scandi high is still in place and the Atlantic still generally held at bay.

Battleground, winner to be decided

[Cecil Hogmanay Melchett]

If your idea of a breakdown is lots of snow, fog and frost then ECM is a breakdown. Have to admit it's not my idea of one.

take a look at the 850's iceberg at 144h,that is not continental air at that stage and they are absolutely not low enough for snow,not even marginal.

[iowpompeylee]

Not really - whilst each model toys with an Atlantic attack, none of them show the attack succeeding in a change of pattern - it is still cold, the Scandi high is still in place and the Atlantic still generally held at bay.

Battleground, winner to be decided

does anybody know where i can find some precipitation maps or radars for europe so i can track the snowstorm supposed to be hitting us on sunday???thank you in advance

[Guest]

Anyway this is actually a cold chart and I`ve seen archives like this that can bring something very special.

http://www.wzkarten.de/pics/Recm1921.gif

Feb 96 or March 06 as possible matches?? Take your pick

Edited January 8, 2010 by CatchMyDrift

[AtlanticFlamethrower]

ECM shows evenly fought cold/mild battle and reload from Sandinavia. This evolution could develop into unevenly fought cold/mild battle and reload, in which case more areas on the margins retain snow depth from the first spell.

12Z JMA T168

00z GEM

This is the evolution to watch out for IMO.

GME 12Z T144

Same pattern as "the jam" JMA and GEM

[J10]

um ECM dumps 1ft of snow and then doesn't really warm up a great deal, however the 72 to 96 evolution is crazy, with far too much southerly Jet interaction with the developing low.

It still doesn't want to gear up the Atlantic though and instead near the end pumps up the pressure to the NE.

I tend to agree, a real chance of some heavy snow if ECM came off. It is unusual to see the ECM so "progressive" in these situation, and perhaps over deepening low pressure, if the GFS was doing this then it would be more understandable.

I think we are starting to see the breakdown insight, however it will not be a quick and easy win for the Atlantic, and I also think there will be a lot of snow to come before the Atlantic finally winds out, perhaps in about 10 days time.

[casparjack]

I know it's deep FI, but the evolution from T+216 to T+240 just looks wrong to me, too much seems to happen in 24 hours?

Anyone else?

[mushymanrob]

Yep the likes of Mr Holmes and GP have been pretty much spot on. GPs analysis that the lows will undercut the UK are certainly demonstrated on the 06z run. I always find it really odd how some get taken in by a couple of runs jumping onto an apparent new trend, how often have we seen this happen, the models have a day of uncertainty only to revert to an earlier evolution on later runs. It might well be that this mornings 00z runs are on to a new trend but I think I’ll wait awhile before jumping to any conclusions.

surely thats the point of FI watching... awaiting the next pattern change and judging what might happen. we all did it when the cold first came into view...

the gfs seemed to pick up first on the attack from the southwest and has stuck to it, other models seem to be joining in, the ukmo in particular. the next fax @120 will be interesting.

ok, my use of the word 'mild' may have been lazy, i didnt mean 10c+ because that certainly wasnt on the cards...maybe 'average' would have been more accurate, however as things stand itll be a right mess and the cold weather certainly isnt on its way out...it just might be.

[nick sussex]

Sometimes we have to except the fact that FI can be rather close, and that looks the case for mid-week next week, with such divergence with what to do with the low to the SW after t+96 - which I think is the limit of reliability atm.

Differences between ECM and UKMO/GFS seem to be that ECM keeps the Atlantic trough intact while the block retreats quickly east over NE Europe - allowing the low to move NE across the UK from Biscay. Whereas UKMO/GFS keep the block firm over Scandi, not really moving, which disrupts the approaching Atlantic trough with a cut-off sfc and upper low ejecting east.

Having said that, as others mention, the uppers are still cold when the low on ECM moves NE over UK, so not a disaster for cold and snow fans and maybe a snow storm likely inland?

FI starts at t+96!!

Good post Nick F

It certainly makes for interesting viewing as to how this will play out. Whilst the ecm is my favourite model theres enough uncertainty given the rest of the model output to make the outlook very uncertain.

[snowlover2009]

can someone tell me how ecm is plausible? I looked at the evolution at 192 to 216 hrs and it just doesn't look right at all. although it doesn't get mild or above average, it still is good for the next proper reload of cold, but i just don't see how some of ecms evolutions make sense from one chart to another. they look odd. hope its off on one

OT: snowing wildly here

[MR EXTREMES]

I know it's deep FI, but the evolution from T+216 to T+240 just looks wrong to me, too much seems to happen in 24 hours?

Anyone else?

another omega block maybe?

[snowlover2009]

another omega block maybe?

yes i said the evolution look dodgy, but i was talking about 192 to 216, although the charts you are showing don't look right. its still good for us coldies though i think

[nick sussex]

can someone tell me how ecm is plausible? I looked at the evolution at 192 to 216 hrs and it just doesn't look right at all. although it doesn't get mild or above average, it still is good for the next proper reload of cold, but i just don't see how some of ecms evolutions make sense from one chart to another. they look odd. hope its off on one

OT: snowing wildly here

I wouldn't worry too much about the model output at that range given the uncertainty much earlier on. As Nick F said earlier FI starts past 96hrs, this is especially important as we are likely to see a major winter storm with massive potential for disruptive snow but don't ask me where yet as the models can't agree on this.