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Model Discussion Thread - 15th Jan


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Posted
  • Location: Hampstead / Cambridge
  • Location: Hampstead / Cambridge

we've learned over the last week not to draw conclusions from 1 run, but the ECM has snow (potentially heavy snow) for parts of southern England from a week today and air cold enough for it from 5/6 days from now. At least the difference of opinion is in a nearish time frame rather than phantom cold spells of times gone where we're looking at 10+ day changes. Wait for overnight development and this time tomorrow, if it's still the same then i'd legitmately get excited since the time frame concerned begins at the end of this week.

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Posted
  • Location: Mid Welsh/English Border
  • Weather Preferences: Snow! Exciting weather!
  • Location: Mid Welsh/English Border

What is great about this run is the kind of cold uppers shown for next weekend again.....especially after the ECMs wobble this morning

ECF0-192.GIF?15-0

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Posted
  • Location: Wellingborough
  • Weather Preferences: snow
  • Location: Wellingborough

How anyone can be pessimistic about the ECM is completely beyond me.

It really seems some wont be pleased unless there 1080mb over Greenland....

Seriously, for goodness sakes, the ECM 12z is BY FAR the best run this winter. An absolute snowfest and very cold, a very potent cold spell.

Of course this could change, and its not quite close enough to get our hopes up just yet!

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Just to add - big divergence 120 So yes ECM could well be wrong- but for now for the snow lovers lets enjoy whats its depicting as we havent had much to enjoy this Winter-

I think we all know that we all know that it might not be that good! :ph34r:

S

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Posted
  • Location: Home: Chingford, London (NE). Work: London (C)
  • Weather Preferences: Winter: cold and snowy. Summer: hot and sunny
  • Location: Home: Chingford, London (NE). Work: London (C)

How anyone can be pessimistic about the ECM is completely beyond me.

It really seems some wont be pleased unless there 1080mb over Greenland....

Seriously, for goodness sakes, the ECM 12z is BY FAR the best run this winter. An absolute snowfest and very cold, a very potent cold spell.

Of course this could change, and its not quite close enough to get our hopes up just yet!

Agree, I don't quite understand the comments about it not being a very good run - it is!

I completely understand being cautious and not getting too excited as there is a long way to go, but if you are judging this run for what it is, then there is no other word to describe it than excellent - particularly in the 120-192 time frame. Plenty of snow and cold potential in those charts.

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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Sadly in deep FI ECM brings the Atlantic back in and really separates from the GFS at T168. So FI starts fairly late then anything can happen from T168 onwards. So a brief bit of winter next weekend and since Country file mentioned it as well I'm fairly confident it will happen.

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

I'd say the key timeframe is 120 to 144hrs, this is where the later ECM output will either crumble or be right in terms of trend, the three key factors are trough dropping into the Continent, ridge allowed to extend from the east and the Azores high displacing .

If you get those then a good chance you'll get the shortwave heading south.

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Posted
  • Location: Mid Welsh/English Border
  • Weather Preferences: Snow! Exciting weather!
  • Location: Mid Welsh/English Border

Just to add - big divergence 120 So yes ECM could well be wrong- but for now for the snow lovers lets enjoy whats its depicting as we havent had much to enjoy this Winter-

I think we all know that we all know that it might not be that good! :ph34r:

S

Yes.......................or it could be even better! hehehehe

Edited by stratty
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Posted
  • Location: Wellingborough
  • Weather Preferences: snow
  • Location: Wellingborough

Agree, I don't quite understand the comments about it not being a very good run - it is!

I completely understand being cautious and not getting too excited as there is a long way to go, but if you are judging this run for what it is, then there is no other word to describe it than excellent - particularly in the 120-192 time frame. Plenty of snow and cold potential in those charts.

Yes an excellent run, no question. Things are really starting to get exciting model watching wise.

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

This might be of interest to tomorrow mornings model output:

The updated NOAA discussions:

OVERALL...ECMWF MODEL GUIDANCE HAS BEEN MORE CONSISTENT THAN GFS

GUIDANCE OVER THE PAST FEW DAYS IN THE 3-5 DAY TIME FRAME AT MORE

MODERATE AND SMALLER SPATIAL SCALES...BUT ALONG WITH OTHER

GUIDANCE CONTINUES TO OFFER SIGNIFICANT RUN TO RUN VARIANCE IN

RECENT FLOW REGIMES AT LONGER 6-7 DAY TIME FRAMES. THIS CAN BE

ATTRIBUTED TO INCREASINGLY PROBLEMATIC TIMING AND STREAM

INTERACTION ISSUES AND IS AGAIN THE CASE TODAY. ENSEMBLE MEANS

HAVE THEMSELVES BY NATURE OFFERED BETTER LONGER TERM CONTINUITY

BUT HAVE NOT BEEN IMMUNE TO UNCHARACTERISTICALLY EVIDENT RUN TO

RUN FLUXUATIONS IN THIS EMERGING TRANSITIONAL PATTERN. PLANNED

WSR WINTER RECON FLIGHTS OUT FROM HAWAII TO GATHER ADDITIONAL

PACIFIC OBSERVED DATA FOR THE MODELS IN AREAS OF NEED TONIGHT MAY

BE ABLE TO AID REDUCTION OF ERROR STARTING WITH TONIGHTS 00 UTC

GUIDANCE RUNS.

Full discussions here:

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

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Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

Agreed Nick - perhaps you can see why I suggested FI was T+96 this morning!

It didn't look so FI this morning to my bleary eyes, but it does now! Though the interesting stuff happens T+144 onwards.

Though after countless operationals the GFS still doesn't want to back ECM, so I'm rather cautious, even though some think the model is inferior to the ECM, it didn't entertain ECM's idea of an easterly this weekend when we got a HP instead. Perhaps we'll get lucky with this second window of opportunity?

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Posted
  • Location: Liphook
  • Location: Liphook

http://www.meteociel...H1-240.GIF?15-0

Launch Torpedo number one under the block

SNOW & More snow 168 192 216 & 240 for the East & SE of the UK ( & NE + elements of scotland)

Doesnt look a classic 'true' cold chart but the 216 has a ridge over the near continent VERY close to the feb 1996 synoptics....

S

Its close Steve, if the flow was a little more amplified then the pattern for 240hrs would indeed be very interesting, especially for areas further north.

That 240hrs could go several different ways...all depends on whether the PV can pull itself together or not, looks very elongated there...

http://www.meteociel...H1-240.GIF?15-0

Launch Torpedo number one under the block

SNOW & More snow 168 192 216 & 240 for the East & SE of the UK ( & NE + elements of scotland)

Doesnt look a classic 'true' cold chart but the 216 has a ridge over the near continent VERY close to the feb 1996 synoptics....

S

Its close Steve, if the flow was a little more amplified then the pattern for 240hrs would indeed be very interesting, especially for areas further north.

That 240hrs could go several different ways...all depends on whether the PV can pull itself together or not, looks very elongated there...

Agree, I don't quite understand the comments about it not being a very good run - it is!

Its a decent run, but no more then that. Having seen some of the insane runs from the last few winters, this is rather bog standard looking run. In the context of the horror of this winter thus far however, its certainly a very good run!

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

http://www.meteociel...=0&map=5&mode=0

Just for reference one of the UK's snowiest days ever- Nowt here in NW kent- missed the main band by 20 miles!!

S

Yes tell me about it! I was living in Wimbledon then and had to watch pictures of snow from that band that ground to a halt to the west of London.

It's a good example of why people shouldn't assume you need a strong northerly or easterly flow to deliver, the chart that Steve posted delivered snow as the surface se flow brought lower dew points and drier air in from the continent which clashed with that Atlantic front, bingo loads of snow to everyone west of London!

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Posted
  • Location: Weymouth, Dorset
  • Location: Weymouth, Dorset

You're the voice of reason on here Stephen.

The ECM run is an improved but doesn't show anything special and it is showing the best synoptic of all operationals this evening.

To be fair, when Stephen gets excited about a run will be the time to evacuate the country!! (in jest ;-) )

Great turnaround from the 12z's tonight and I think it's very notable nobody has congratulated any model on any sort of done deal unlike when the ECM dares to waver from its thinking of the past few days. Why? Because those that have called for this being the most likely outcome also know there is plenty that can go wrong.

Still knife edge stuff coming up now. The Azores needs to stay as far west as possible then I think it's game on. Tonight's lovely ECM charts have come about thanks to that dawdling system coming off the Eastern seaboard, if we see the GFS edge a bit closer with its thinking over the next day or so we may even get some sort of cross-model agreement!

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Posted
  • Location: st albans
  • Location: st albans

At the risk of posting a one liner, jma not so good compared to yesterday. Ecm pulls a run from another of its ens clusters. There were 4 this morning and I think the 12z op came from the smallest one!

Some of the less experienced should appreciate that a lot of the more extreme scenarios being talked about reflect the ecm 12z run rather than what the posters really expect to happen.

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Posted
  • Location: Dublin
  • Location: Dublin

Lol Matty if the ECM at 168hrs isn't special then I don't know what is.

I think we should just look at the trend not the detail, thats liable to change, if the low is forced to disrupt sending a shortwave south and with a strong ridge to the east this opens up lots of opportunities.

The key timeframe still remains getting the trough to sink into Europe far enough west and the Azores high to displace far enough to the west. If we get that then the ECM isn't a fantasy scenario.

Sorry Nick totally disagree, don't know how you could call this chart 'special'.

Its a decent chart for mid winter, absolutely nothing special about it, unfortunately, but as has been said

a good run from the ECM and something to build on, would bring a real taste of winter for many :)

Recm1681.gif

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Posted
  • Location: Wellingborough
  • Weather Preferences: snow
  • Location: Wellingborough

Sorry Nick totally disagree, don't know how you could call this chart 'special'.

Its a decent chart for mid winter, absolutely nothing special about it, unfortunately, but as has been said

a good run from the ECM and something to build on, would bring a real taste of winter for many :)

Recm1681.gif

comparing it to this winter, it most certainly is special. A very snowy and seasonal chart. In terms of snow potential, it is special, perhaps not in terms of deep cold.
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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Sorry Nick totally disagree, don't know how you could call this chart 'special'.

Its a decent chart for mid winter, absolutely nothing special about it, unfortunately, but as has been said

a good run from the ECM and something to build on, would bring a real taste of winter for many :)

Recm1681.gif

Lol! so a real taste of winter given the dire winter so far is nothing special!

I do understand what you're saying Matt but put aside the detail and just look out for the trend, think of the possible scenarios that occur when you have this type of set up.

Don't be constrained by the operational detail, the 144hrs ECM chart here:

http://www.meteociel.fr/modeles/ecmwf.php?ech=144&mode=1&map=1&type=0&archive=0

In terms of trend and at only 144hrs and not in the far reaches of FI and by one of the big 3 is IMO the best chart of the winter..

Of course we've got some of the lesser models showing very good charts but for one of the big 3 to have that at 144hrs is very positive.

Again I would stress though the crucial 120 to 144hrs timeframe isn't set yet, we need to see cross model agreement.

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Posted
  • Location: cambridge - cambridgeshire
  • Location: cambridge - cambridgeshire

To be fair, when Stephen gets excited about a run will be the time to evacuate the country!! (in jest ;-) ) quote of the day :rofl:

The model wobbles i have observed over the past few days have reminded me of feb 2003 when GFS didnt nail the snow then until 72hrs before it happened.Lesson i have learnt after 12 years model watching is dont compare each GFS run to the last compare the 06Z (example) to the next 06Z.In my opinion from models i have seen there is something on the horizon cold wise how long and how snowy i would say be nailed by wednesday earliest

Edited by baldie
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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

i'm confused now.is there a southern bias regards the charts and their potential or are we looking at a grasp of winter for us up north?

Theres no bias as we don't know where that shortwave will track if it verifies.

We're just trying to get some cold weather into the UK, I'd worry about that first before any snow, of course for me here I do like the ECM as it would deliver some snow to the Pyrenees and even here a bit lower down so I hope it verifies!

That is of course a big IF!

At this rate given past history once the models pick up a retrogressing signal they may well just shunt everything so far west that the shortwave hits Spain, you would however end up with an easterly instead and given your location that wouldn't be too bad!

Edited by nick sussex
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Posted
  • Location: st albans
  • Location: st albans

seeing as how uncertain next weekend is, i thought i'd have a dip into the 12z gefs parallel, remembering that the 00z were so interesting. those of a 'nervous disposition' may not want to visit this page

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=192&code=0&mode=0&carte=1&runpara=1

take the time to follow each run through. some are blocked, some are zonal but plenty are incredible. the most important thing to note is the continued disintegration of any large segment of vortex in a position to stop us getting deep cold on most runs. methinks the last week of jan and beyond could be rather interesting, ignoring what the 6/10 day period may hold.

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seeing as how uncertain next weekend is, i thought i'd have a dip into the 12z gefs parallel, remembering that the 00z were so interesting. those of a 'nervous disposition' may not want to visit this page

http://www.meteociel...rte=1&runpara=1

take the time to follow each run through. some are blocked, some are zonal but plenty are incredible. the most important thing to note is the continued disintegration of any large segment of vortex in a position to stop us getting deep cold on most runs. methinks the last week of jan and beyond could be rather interesting, ignoring what the 6/10 day period may hold.

possibly the BEST WAA chart in history

http://modeles.meteociel.fr/modeles/gensp/run/gensnh-6-1-240.png?12

S

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Posted
  • Location: Weymouth, Dorset
  • Location: Weymouth, Dorset

seeing as how uncertain next weekend is, i thought i'd have a dip into the 12z gefs parallel, remembering that the 00z were so interesting. those of a 'nervous disposition' may not want to visit this page

http://www.meteociel...rte=1&runpara=1

take the time to follow each run through. some are blocked, some are zonal but plenty are incredible. the most important thing to note is the continued disintegration of any large segment of vortex in a position to stop us getting deep cold on most runs. methinks the last week of jan and beyond could be rather interesting, ignoring what the 6/10 day period may hold.

I know, it does seem to be shaping up for an 'interesting' end to the month and number 7 and 13 always seem to be in the mix!

This is reminding me more and more of exactly the same time of year 26 years ago, striking similarities in a lot of respects.

Edited by s4lancia
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