Model Output Discussion - 2nd March Onward

[Panayiotis]

One can hope that those charts are modified a bit. I personally find wetterzentrale a lot more reliable and Gavin p would probably agree with me as he uses it too. Meteociel sometimes acts like it has bugs with it that aren't fixed in time. Those charts cheese rice you have posted are very alarming indeed and weather that isn't even remotely Springlike.

Sorry but what? Its just a website which displays the images produced by certain models, no website alters what is given. What is shown can easily happen in March if part of the PV moves to N.Europe (which has been the consistent trend this week) and we get a direct hit from the east or more especially the NE (and im not saying we will!), a statement like that, I would find more appropriate if it was April. Edited March 3, 2013 by Panayiotis

[Guest pjl20101]

You are correct there and like some things sometimes it happens and sometimes it doesn't. Think yes I agree and shouldn't be too concerned at this stage of the spring season. Hopefully the PV should modify itself on the other hand.

[Jason M]

GFS has gone a bit moneysupermarket (epic) this morning. Looking more than a bit ECMish as well.

Coldest spell of the winter coming up?

Jason

Edit, looking at the ensembles this morning which are out to 192 hours as I write they have trended much colder and were no longer looking at day 10. Going to be a fun week me thinks ;-)

Edited March 3, 2013 by Jason M

[Captain Shortwave]

Agreed, the ensemble mean pressure chart at T180 from this mornings GFS looks pretty much identical to the T192 mean from ECM yesterday. Also the mean temperature drops to -8 for a time out in FI before rising again later (usual scatter). There is a lot of support for a cold spell during mid-March now with the groundwork in the semi-reliable time frame. Haven't looked at individual charts but sure there are probably a lot of epic perturbations in there.

Also do I spot UKMO doing it's own impression of the GFS. Looks a lot better than yesterday afternoons but still not GFS/ECM like just yet.

[bluearmy]

The ecm op hangs a ridge to our east to prevent the cold advecting west as effectively as yesterdays 12z. However, at days 5 and 6 we have pretty decent x model agreement. The ecm op at days 7 and 8 should only be given strong weighting if it has good ens support. 2 hours to wait on that one.

The odds on an anomolously cold and potentially snowy period have shortened this morning. If the gefs are right to dig the cold sw and then take the core of it further west as the depressions run west to east across the base, some areas of the uk (currently n england) would be paralysed. As we know, these things rarely verify like that with the ah popping up to cut off the flow of enery or the vortex sinking across us, meaning the shortwave track is further to our south. What is sure is that the number of people on this thread is going to soar again once word gets out. As more of the less cold members drop out of the suite, wtch those preicted mean maxes sink further. Get some more hay and black sheets ordered for cheltenham!

Edited March 3, 2013 by bluearmy

[winterof79]

Take cover.

http://www.meteociel.fr/modeles/ecmwf/runs/2013030300/ECH1-192.GIF?03-12 fine chart

http://modeles.meteociel.fr/modeles/gfs/runs/2013030300/gfsnh-0-168.png?0 GFS agrees

http://modeles.meteociel.fr/modeles/gem/runs/2013030300/gemnh-0-168.png?00 GEM

http://www.meteociel.fr/ukmo/runs/2013030300/UN144-21.GIF?03-06 UKMET as far as it goes.

Just because it very rarely happens does not mean it wont this time.Its the weather

[winterof79]

At this range i will take that for Northern England.

http://modeles.meteociel.fr/modeles/gens/graphe_ens3.php?x=271&ext=1&y=46&run=0&runpara=0

[Supacell]

Looks like the dry, settled spell has another 3-4 days left in it, we then get a milder spell of weather but with periods of rain and stronger winds. It doesn't appear any extreme rainfall or winds are likely though with the charts below fairly typical of midweek to the end of the week. Charts from the GFS/ECM/UKMO showing a broad agreement for this to be the weather pattern next week (below is GFS and ECM for 96hrs).

It's beyond next weekend that the excitement once again builds as cold/very cold air sourced over Scandinavia looks to push SW across the UK (showing on both the ECM and GFS now). Below is the set up by the weekend as the winds turn more to the east and the cold air approaches from the northeast, with the -5 850's almost reaching NE Scotland.

Next week both the ECM and the GFS see cold weather flooding into the UK with similar but different evolution to get the cold air in. The GFS (first chart) has an area of low pressure to our east pulling in very cold air sourced across Scandinavia and the Arctic in a N'ly wind and we would be likely see a lot of snow showers in this flow, whereas the ECM brings in very cold air from NE Europe and Scandinavia around an area of high pressure to the west of us.

Even at this range there is definitely enough similarities between them to have me sit up and notice. But, at 240 hours I would still be very cautious and i must point out that i am not forecasting this will happen, rather what i see on current model output. However, definitely some interest back in the model output discussion next week and i expect to see the return of a fast running thread, bickering, shouting, toy throwing and a little bit of useful technical input thrown into the mix too

Edited March 3, 2013 by Supacell

[IDO]

As the GEFS have been showing for some runs the predicted cool down continues to be progged from next weekend. As more ensemble members join the trend the mean continues to fall:

This is for London, so further north the mean is colder.

The 2m temps highlight the fall:

The GFS op is obviously a very good run for the north, but at the moment it reflects close to the best "cold" potential, so may downgrade.

The GFS control also close to the op from next weekend:

However although the cool down is looking very likely now, the ops (GFS & ECM) still haven't nailed where the colder uppers will go and hence whether it will be wintry or just cold (for most).

ECM at T240: GFS at T240:

Big differences.

This morning's ECM is another good run (in FI) and a similar outcome to yesterday's 12z with cold uppers coming in from the NE (though delayed by c.24 hours).

A mild few days still forecast in the short term (Midlands South):

Dry early then wetter.

[Frosty.]

Quite big temperature contrasts in the week ahead, northern britain never really turns milder, it's only the southern half of the uk that looks mild with temps around 11-12c but 13-14c is possible in southern england later in the week. The week starts with ridge conditions and more sunshine for the south, cloudier in the north, pressure then falls and rain spreads into the southwest and west of the uk and then spreads out more widely but the heaviest and most persistent rain probably becoming more concentrated across central and northern britain after midweek.

Now all this is only half the story, the gfs 00z shows the mild weather becoming confined to the far south of england by next sunday with the rest of the uk turning progressively colder from the north with ppn becoming more wintry, the arctic high pushing southwest to the northwest of the uk, the scandi trough spreading southwest towards the uk, very dec 2010 charts from the gfs 00z in FI, the ecm 00z not as good as the gfs, funnily enough the gfs 00z is more like the ecm 12z last night whereas the ecm has toned things down a bit this morning, it's still cold though and appears to be reloading a potential Northerly at T+240 with retrogression possibly occuring but the gfs is a fast track to cold and snow with very scandinavian type synoptics, by early/mid march standards, the gfs would be incredible.

Edited March 3, 2013 by Frosty039

[TEITS]

Wow what a flip from the ensembles this morning.

From a forecasting perspective im delighted with this mornings output. Whats interesting is some of the ensembles bring in the cold much earlier but also much colder than the GFS OP. A few drop as low as -13/14C.

http://cdn.nwstatic.co.uk/ensimages/ens.20130303/00/t850Cambridgeshire.png

You have to take your hat off to Steve M though. He said we would see the +144 period upgrade towards cold and he said this around 48hrs ago. When you look at this mornings output he was spot on.

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

when you think its safe to put the winter stuff away dont looks like some cold weather coming again!!

[Frosty.]

You have to take your hat off to Steve M though. He said we would see the +144 period upgrade towards cold and he said this around 48hrs ago. When you look at this mornings output he was spot on.

I will take my hat off to steve m if it happens

Edited March 3, 2013 by Frosty039

[bluearmy]

What surprises me is that people are surprised. There have been enough hints on naefs and the extended ECM ens have had a cold cluster for the past week. Whilst there is never any guarantee that these solutions verify, the fact that they become the favoured model output should not be a surprise. Just a note that the only important variation on the current week 2 model pattern and the cpc anomolys from Thursday is the upper ridge towards Greenland being far more solid than the weakish feature shown then. At the moment my interpretation looks more likely but as we get closer to verification, given the propensity for predicted Greenland height rises to drain away this past few months, a less cold solution may well come into view.

[Purga]

Great set of ENS this morning!

Good precipitation spikes as well so hopefully we won't end up with another 'dry' boring cold shot.

[Polar Maritime]

Very interesting chart's this morning, as the trend for a cold spell from the E/N/E in around a weeks time looks to be firming up. How cold and how long it will last is all open to question.

Don't take every run as gospel.. as there will be some wild swing's in the output, as the models always struggle with these set-up's.

It's looking like this spring could turn out the complete polar opposite to the last 2/3 years, where we enjoyed some lovely early summer weather.

Some fantastic model watching to come over the next few days.

Winters not over, until it's over !

[No Balls Like Snow Balls]

The 4 models I have looked at this morning GEM, GFS, ECM and UKMET all show pressure rising in between Greenland and Scandi upto T144.

The overnight ECM and GFS T2M TMAX ensembles continue to show a sharp decrease from next weekend onwards. They are colder than there own previous runs. Still not cold enough to be considered a big freeze or for any snow, with maxes of 4-5c being progged by the GFS and 5-6c by ECM. Cold for March but not amazingly so. Plenty of time to continue the trend downwards or the flip side - plenty of time for it to go wrong from a deep cold perspective. What i have noticed is that the ECM op run seems to keep the really cold uppers @ T240 more often than not.

Overall confidence is pretty high for the cooling off of temps next weekend from mid-weeks double figures, but how cold it gets is still a long way from being sorted.

[TEITS]

I will take my hat off to steve m if it happens

Regardless of whether it happens im just impressed with how the models have upgraded when he said they would.

What members especially newcomers need to realise is following the models isn't just posting what they are suggesting because without being rude I could teach my mum how to do this. This isn't forecasting, the trick of following the models is knowing if they are right or wrong and if they are wrong how and what is likely to be correct. Some members do this especially the likes of Steve M & Nick Sussex.

ECM mean continues to suggest an E,ly which could become a NE,ly.

[nicknacknoo]

Regardless of whether it happens im just impressed with how the models have upgraded when he said they would.

What members especially newcomers need to realise is following the models isn't just posting what they are suggesting because without being rude I could teach my mum how to do this. This isn't forecasting, the trick of following the models is knowing if they are right or wrong and if they are wrong how and what is likely to be correct. Some members do this especially the likes of Steve M & Nick Sussex.

ECM mean continues to suggest an E,ly which could become a NE,ly.

http://www.meteociel...1-192.GIF?03-12

Yes, and what is particularly nice is that these posters offer some reasoning behind their analysis. Not all members of the site are studying meteorology or climatology at degree+ level so it is nice to have some pointers in using the charts for prediction. Well done and thanks to those posters who do this.. including you TEITS

[No Balls Like Snow Balls]

Regardless of whether it happens im just impressed with how the models have upgraded when he said they would.

What members especially newcomers need to realise is following the models isn't just posting what they are suggesting because without being rude I could teach my mum how to do this. This isn't forecasting, the trick of following the models is knowing if they are right or wrong and if they are wrong how and what is likely to be correct. Some members do this especially the likes of Steve M & Nick Sussex.

ECM mean continues to suggest an E,ly which could become a NE,ly.

http://www.meteociel...1-192.GIF?03-12

We should also point out that not one of the more experienced members is correct 100% of the time and have all got it wrong sometimes. Even the professionals. And new members should not hang off every word of one person but look at the wide variety of postings from coldies and mildies alike.

Edited March 3, 2013 by No balls like Snow Balls

[mushymanrob]

I posted the other day that anomaly charts and Met forecasts can change on a dime

and it very much looks like this will be one of those times.

... and so do the ops... , just like they did yesterday.

i'm confused - the anomoly charts do support the broad ecm solution.

not yesterday morning they didnt...however today is another matter!

The ECM solution is NOT overcooked, these uppers are wholly expected when you consider the exceptional cold air pushing into NE Europe.

ALL models show this cold pool, the question arises as to whether a.) we can push the cold air south and b.) whether the cold air can be advocated westwards. If we do push the cold air towards the UK then uppers below -10 perhaps even -15 should be expected.

not overcooked? well this mornings ecm is alot more sober then last nights, even the ecm itself has downgraded the severity that only 12 hourse earlier it was predicting. this mornings is far more plausible.

Very surprised at some of the posts this evening.

Firstly why are some surprised by the ECM and then suggesting it wont happen. I have been posting ensemble means these past few days and all of which have supported an E,ly around the 10th March. What has been uncertain is how cold this E,ly could be.

Are upper temps below -10C exceptional and too extreme for the ECM to be correct? Well the answer is no because very cold runs have frequently been appearing on the ensembles and some have been as low as -15C.

bib.... not quite dave, i said its highly unlikely to happen as last nights 12z run had predicted, -13c uppers for eg. plus its in fi, so that chances of any chart verifying that far out is remote. this mornings ecm is far more likely, its believable, thats not saying that the -13c upper catagorically wont happen, just that its highly unlikely this far off. IF upper that cold are predicted upto t120, then its likely to happen.

well this mornings anomaly charts do now support the possibility of some kind of significant cooling 8-10 days time.

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

fair play.

this far off though speculating about the detail of severity or length is frankly a waste of time. we have to get there yet and its still possible for the usual downgrade to take effect. until then we have several dry, bright nicely warm days (time of year taken into account), before it gets more mobile with wind and rain later in the week.

[mushymanrob]

We should also point out that not one of the more experienced members is correct 100% of the time and have all got it wrong sometimes. Even the professionals. And new members should not hang off every word of one person but look at the wide variety of postings from coldies and mildies alike.

exactly....! its human nature though to 'like' the people who tell you what youd prefer to hear.

[Frosty.]

Definately the balance has tipped in favour of a cold spell developing in around 6 days time, ensemble support has significantly increased and we have an epic gfs 00z from T+192 onwards but the foundations are laid well before then, fingers crossed.

[TEITS]

We should also point out that not one of the more experienced members is correct 100% of the time and have all got it wrong sometimes. Even the professionals. And new members should not hang off every word of one person but look at the wide variety of postings from coldies and mildies alike.

Very good point.

Sometimes it must be difficult for members to know what to believe because some posts will be biased towards cold or mild. Having said this I try to be objective and if I think mild weather is likely then I will state this. Im sure some members will remember my miserable posts during xmas and into the New Year!

Back to the output and what really excites me is actually the time of year funnily enough. If the output continues with the same trend then upper temps between -10 to -13C remain possible. Now inland convection could really develop because the sun heating the ground during the morning combined with the cold higher up could cause some beefy showers to develop. Furthermore a NE,ly with upper temps of -13C could bring some heavy falls of snow.

[A.J]

We should also point out that not one of the more experienced members is correct 100% of the time and have all got it wrong sometimes. Even the professionals. And new members should not hang off every word of one person but look at the wide variety of postings from coldies and mildies alike.

Carlsberg don't do model output posts, but if they did.......

Quite possibly the accurate post ever made in this thread!

just seen TEITS reply...another very good post