Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Winter Model Discussion - 11/01/13 00z Onwards


reef

Recommended Posts

Posted
  • Location: Kesgrave, just East of Ipswich
  • Weather Preferences: April!
  • Location: Kesgrave, just East of Ipswich

I'm not buying the ECM this morning; that may be the eventual pattern but it looks far too quick to sink the high and flatten everything to me, especially from T96 to T120.

It may have the best verification stats at mid range, but it doesn't always get it right either! Let's see where it goes tonight......

Edited by Chalk Serpent
Link to comment
Share on other sites

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

I checked the archived resolution thread last night and it doesnt say. However, i am sure that the ukmo raw changes resolution at T72. If its higher than ecm op, it wont be by much as that is at 16km!!

Exeter have the nae to refer to in order to check if ecm is making upstream decisions early which have big consequences. It isnt often that ecm op has the wrong pattern at short range. Very rare.

Yes the ECM is normally rock solid at short range but the weird thing is that its started this sinking high trend for quite a while and it seems like such a strong signal to it that you would have expected some movement from the GFS and UKMO on their 00hrs runs especially that it starts going pear shaped between 72 and 96hrs.

It's going to be a long day because regardless of what the GFS 06hrs run shows we'll have to wait for this evening. Even more insulting from the ECM was its later pattern which shows nothing of remote interest, at least night showed a few crumbs.

Link to comment
Share on other sites

Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

stick with the ukmo, I think the ecm is having a wobble like it did famously before the nov/dec 2010 freeze. It's good to see the gfs has fully recovered from it's recent illness.

post-4783-0-32091600-1357976735_thumb.pn

Link to comment
Share on other sites

Posted
  • Location: Llanharan, South Wales
  • Location: Llanharan, South Wales

not sure I like Fergie's update in the regional's for the south - was posted last night so may be a little out of date now - however the BBC graphics show the front as much weaker precipitation wise than I expected a few minutes ago on their live broadcast.

Latest modified NAE continues trend of lessening PPN rates through evening; Brecon Beacons remains our only dead cert for settling snow across southern UK to any reliable degree (based on MOGREPS & 4KM snow modelling). Elsewhere, remaining very marginal depending on PPN intensity. Incidentally, given tephi profiles, a key element we need to cater for is possibility of convective cells developing immediately behind the front and thereafter overrunning the colder air. In turn, these would locally increase PPN instantaneous rates in some southern areas, which would readily turn to snow through evaporative cooling effects.

Link to comment
Share on other sites

Posted
  • Location: Belper, Derbyshire
  • Weather Preferences: Thunderstorms
  • Location: Belper, Derbyshire

It will be interested to see if the ECM is an outlier on the ensembles.

GFS/UKMO finally on the same page with some great charts for cold and snow, and then the ECM turns. Lets hope it is an outlier. When do the ECM ensembles come out?

Link to comment
Share on other sites

Posted
  • Location: NR Worthing SE Coast
  • Location: NR Worthing SE Coast

The ECM's even more progressive this morning than last night and the last few runs its sunk the higher quicker and quicker.

It's a shocker, after viewing the GFS and UKMO first I never expected to see such dismal output from it.I don't think I've ever seen the ECM be totally wrong within T96hrs which worries me!

A question BA I can't remember but is the UKMO higher resolution upto 72hrs than the ECM operational because the first problems begin to show up there?

surprised with your knowledge nick that you think ecm is anywhere near correct,it looks very suspect to me and that sudden jump from t96 to t120 with the high pressure sinking fast in only 24 hours?..garbage

bet its one of the warmest runs in the ensemble pack!

Link to comment
Share on other sites

Posted
  • Location: sheffield
  • Weather Preferences: cold ,snow
  • Location: sheffield

not sure I like Fergie's update in the regional's for the south - was posted last night so may be a little out of date now - however the BBC graphics show the front as much weaker precipitation wise than I expected a few minutes ago on their live broadcast.

Latest modified NAE continues trend of lessening PPN rates through evening; Brecon Beacons remains our only dead cert for settling snow across southern UK to any reliable degree (based on MOGREPS & 4KM snow modelling). Elsewhere, remaining very marginal depending on PPN intensity. Incidentally, given tephi profiles, a key element we need to cater for is possibility of convective cells developing immediately behind the front and thereafter overrunning the colder air. In turn, these would locally increase PPN instantaneous rates in some southern areas, which would readily turn to snow through evaporative cooling effects.

id agree there.looks like a narrowing band compared to last nights beeb forecast
Link to comment
Share on other sites

Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire

Yes the ECM is normally rock solid at short range but the weird thing is that its started this sinking high trend for quite a while and it seems like such a strong signal to it that you would have expected some movement from the GFS and UKMO on their 00hrs runs especially that it starts going pear shaped between 72 and 96hrs.

It's going to be a long day because regardless of what the GFS 06hrs run shows we'll have to wait for this evening. Even more insulting from the ECM was its later pattern which shows nothing of remote interest, at least night showed a few crumbs.

Although I agree the ECM at short range is right more than wrong ,I'm very dubious as to the strength of the PV , It's against all signals. The gfs with its vortex shape and strength fits the bill a lot more than the ECM northern H map , I'm not dismissing the ECM because of its sheer quality but if I was forced to make a decision looking at all the details with what's happened this last week also given the vortex split I would side with the gfs , simply because it shows everything you would expect to see after a vortex split .

Link to comment
Share on other sites

Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

It looks like a lot of snow for scotland tomorrow which will then spread south into england and wales on sunday night and monday, some areas are going to be seriously disruped by the start of next week.cold.gif

Link to comment
Share on other sites

Posted
  • Location: Ireland
  • Location: Ireland

Anyone know of a site that shows the ECM progression in smaller time periods. I can't see what happens to the 850s between T48 and T72. Time gap is to big.

Iceland met

http://en.vedur.is/weather/shipping/atlantic/

To see up to the 240 hrs, change the timestamp in the url to the hour you want

Edited by Su Campu
Link to comment
Share on other sites

Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire

So the model chaos continues this morning.

Every morning when I view the models its always in the order of UKMO, ECM, GFS. Now after viewing the UKMO/ECM my initial thought was the ECM is more likely after viewing the 18Z GFS. However I then view the 0Z GFS and its completely different. When it comes to potential in the medium range the UKMO is clearly the best followed by the GFS/GEM. The strange thing about the model output is normally when it comes to an E,ly the UKMO is always less keen and yet remains firm from last nights 12Z.

The difference between the models isn't surprising though. The GEFS ensembles have also shown a similar split during yesterday (haven't looked at 0Z yet) as we had around 50% supporting the ECM and the other 50% being similar to GEM/UKMO. So really members should view the output at the moment with the attitude of a 50% chance the ECM right and 50% UKMO is right.

Link to comment
Share on other sites

Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire

not sure I like Fergie's update in the regional's for the south - was posted last night so may be a little out of date now - however the BBC graphics show the front as much weaker precipitation wise than I expected a few minutes ago on their live broadcast.

Latest modified NAE continues trend of lessening PPN rates through evening; Brecon Beacons remains our only dead cert for settling snow across southern UK to any reliable degree (based on MOGREPS & 4KM snow modelling). Elsewhere, remaining very marginal depending on PPN intensity. Incidentally, given tephi profiles, a key element we need to cater for is possibility of convective cells developing immediately behind the front and thereafter overrunning the colder air. In turn, these would locally increase PPN instantaneous rates in some southern areas, which would readily turn to snow through evaporative cooling effects.

He was talking about today's low !! Just chill out and make yourself a coffee and come back lol!! Have a look at the fax , you will see 2 if not 3 frontal systems crossing the country , the first is Sunday night we have the "weaker" band , which is chased readily by the second "main" front , this will double the size of the ppn and significantly strengthen the ppn , then we have a tail to the low pressure that can pack a punch , that will cross us Monday night , just sit back and enjoy the ride.

Link to comment
Share on other sites

Posted
  • Location: South Essex
  • Location: South Essex

Looking good this morning IMHO.

Re resolution of models my understanding is that METO runs out to 72 at a higher res than the others but its res then drops pretty sharply thereafter. I suspect this has a lot to do with why the 144 charts are often not very good. Because the issues are early in the runs I'd back METO this time though over ECM.

Also, the METO / GFS scandi high solution is the logical one and I mentioned last night that I was surprised we were not seeing this reflected more strongly in the models. The ensembles were trending this way after the 18z run but now the opps are picking up on this. A col covering most of Northern Europe simply didn't make sense.

Strong backing for a scandi high in the GFS ensembles now.

Jason

Link to comment
Share on other sites

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

surprised with your knowledge nick that you think ecm is anywhere near correct,it looks very suspect to me and that sudden jump from t96 to t120 with the high pressure sinking fast in only 24 hours?..garbage

bet its one of the warmest runs in the ensemble pack!

Knowledge has nothing to do with it. You can't just bin the ECM at that range, its not at 144hrs, the problems start between 72 and 96hrs.

It may well be wrong but its synoptics are not implausible, I've happily in the past called a run garbage or synoptically unlikely but I'm certainly not going to do that with the ECM.

Of course I'd love it to be totally wrong as its a shocker but before everyone spends the whole day rubbishing the ECM at that range they should look at past history.

Anyway the best I could find to call into question the ECM output is some comments from NOAA this morning, I don't think this makes a great deal of difference to us as its really a minor issue but anyway this is it:

...FARTHER TO

THE SOUTH THE ECMWF IS STRONGER WITH A SECONDARY LOW FORMING ALONG

THE FRONT OVER MISSISSIPPI EARLY SUNDAY...WHICH HELPS TO SLOW ITS

FRONTAL TIMING AND RESULTS IN HIGHER QPF WEST OF THE LOW TRACK.

WITH NEARLY ALL OTHER SOLUTIONS WEAKER...INCLUDING ITS OWN

ENSEMBLE MEAN...RECOMMEND DISCOUNTING THE ECMWF. THUS...THE MOST

RECOMMENDED SOLUTION IS THE GFS.

I've looked at the outputs from 48hrs to 72hrs but really the problem is the handling of energy near Iceland, anyway at least it maybe a little wrong upstream. I would feel much happier if it had a data issue!

Edited by nick sussex
Link to comment
Share on other sites

Posted
  • Location: L-O-N-D-O-N
  • Weather Preferences: Snow, frost, ice,Spanish plumes, thunderstorms, heat.
  • Location: L-O-N-D-O-N

Hello all. Very long time weather watcher here with a middling knowledge of weather prediction, but first time poster. Why oh why must the NWP keep chopping and changing? doh.gif Is it this Shannon Entropy (ie uncertainty lol) we keep hearing so much about?

Edited by TrickyRicky
Link to comment
Share on other sites

Posted
  • Location: South Essex
  • Location: South Essex

BOM is running out and is completely different to everything else this morning.

If I was on my PC I'd post the chart. Tbh it just looks messy and I think its performed poorly of late even relative to other models.

Jason

Link to comment
Share on other sites

Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire

Just been through the ensembles upto +180 and little support for the ECM to be honest. Generally speaking the GEFS ensembles retain heights across Scandi and any Atlantic LPs going under rather than over.

Another thing worth mentioning is I noticed yesterday the poorer GFS runs were the 06/18Z which are generally regarded as the least accurate due to differing data used. Now todays 0Z ECM is actually similar if I recall to yesterdays 06/18Z. So what I expect today is the 06Z to be less keen on retaining the cold spell but the 12Z to be similar to the 0Z.

Personally I am never happy if the ECM isn't on board and generally we have seen 3 poor runs in a row. However I have seen the ECM go off one one before although this does not occur often. I recall Dec 09, 2010 it lost the plot for a few days!

Link to comment
Share on other sites

Posted
  • Location: Bournemouth
  • Weather Preferences: Dry mild or snow winter. Hot and humid summer.
  • Location: Bournemouth

Ens out soon. Then we can see where it sits. Has to be on the milder side doesn't it? What ever happens along day ahead. Three runs before the ECM. Lets hope the ECM run isn't confirmation of a break down.

Link to comment
Share on other sites

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

Wow. Very interesting stuff, so now it's UKMO / GFS v ECM.

Back to tipping points again and viewing the 3 all through again it does seem to me that at +96 is where it happens. ECM has a small shortwave sat N of Scotland and the NE high can't ridge westwards, energy is deflected E through Iceland, and no way back for cold for a good few days after that. Seeingwhere this sits in the ensembles will be of interest in about an hour. I'd like to dismiss it but it's been way too consistent and it usually has a good grasp of things out at 4 days. But not always, it has form in having such wobbles so the next 2-3 ones will be imperitive.

All good fun!

Edited by s4lancia
Link to comment
Share on other sites

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

Just been through the ensembles upto +180 and little support for the ECM to be honest. Generally speaking the GEFS ensembles retain heights across Scandi and any Atlantic LPs going under rather than over.

Another thing worth mentioning is I noticed yesterday the poorer GFS runs were the 06/18Z which are generally regarded as the least accurate due to differing data used. Now todays 0Z ECM is actually similar if I recall to yesterdays 06/18Z. So what I expect today is the 06Z to be less keen on retaining the cold spell but the 12Z to be similar to the 0Z.

Personally I am never happy if the ECM isn't on board and generally we have seen 3 poor runs in a row. However I have seen the ECM go off one one before although this does not occur often. I recall Dec 09, 2010 it lost the plot for a few days!

Dave was that the modelling of the piece of PV dropping south where it placed it hundreds of miles further west than the other guidance?

I would have been happier if it was wrong at 144hrs, would give us a bit more time to play with.

For what its worth the latest available data we'll see before the next GFS 06hrs run is the NAM which is currently coming out, I will be interested to see what it does with energy near Iceland.

Anything that possibly calls into question the ECM is fine by me!

Edited by nick sussex
Link to comment
Share on other sites

Posted
  • Location: Burwell, Cambridgeshire
  • Location: Burwell, Cambridgeshire

Ens out soon. Then we can see where it sits. Has to be on the milder side doesn't it? What ever happens along day ahead. Three runs before the ECM. Lets hope the ECM run isn't confirmation of a break down.

not sure it's worth panicking too much... yet!

We have some amazing goodies on offer this week, that we would have given a back tooth for in December. However, I realise there is a touch of IMBYism in that comment, as Westerners may now not view the output with quite the same excitement.

Yes, a concern to not have ECM fully on board, though I don't think it's worth getting hung up about a breakdown even before the most exciting period of winter begins. Cold blocks and milder air are always finely nuanced and notoriously hard to predict in terms of breakdown. I seem to remember that in 2009 the Met Office were saying "no sign of the end to cold" but by lunchtime that day the cold air was rapidly dissolving away.

So: no point getting concerned yet. Let's see where the ECM sits in its ensembles in a few minutes but I won't be panicking because (a) plenty of interest in the short-term this week; (b if (a) does come true then we might appreciate a milder interlude (and as this fits perfectly with some of the experts' projections it has some credibility about it) and © it's almost certainly wrong in its detail anyway.

Enjoy the output! Even if it all departs at 120/144, this sort of week is pretty rare in a UK winter and if we hadn't been spoiled with a few mega events in the last 4 years, we would have been absolutely drooling over the next few hours.

Edited by BurwellWeatherWatch
Link to comment
Share on other sites

Posted
  • Location: Carlisle, Cumbria
  • Weather Preferences: Atlantic storms, severe gales, blowing snow and frost :)
  • Location: Carlisle, Cumbria

According to Matt over on Twitter the 00z ECM has support for the op.

Matthew Hugo â€@MattHugo81

00z EC ENS not playing ball either and support the ECM model with milder Atlantic air moving in by Fri/Sat of next week.

Edited by Liam J
Link to comment
Share on other sites

Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

The ECM ensembles for Reading show temp wise the 0z is a massive mild outlier:

http://www.theweathe...1-13-21-15.aspx

Post 212

Though the mean does warm up.

Edited by i'm dreaming of...
Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-29 07:13:16 Valid: 29/03/2024 0600 - 30/03/2024 0600 THUNDERSTORM WATCH - FRI 29 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    Difficult travel conditions as the Easter break begins

    Low Nelson is throwing wind and rain at the UK before it impacts mainland Spain at Easter. Wild condtions in the English Channel, and more rain and lightning here on Thursday. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...