nick sussex

Its bite your finger nails time as if this low verifies a lucky location that remains on the cold side of this throughout the precip could receive some significant snow,again its impossible to call this until within 24hrs as small distances could see heavy rain whilst a location 50 miles further north some very large snow totals. Someones going to be very happy come the day and someone else really peeved off, of course as it clears areas that may have had a wintry mix may see this turn back to snow before clearing. The model drama continues!

I have posted this link a few times this evening but the discussions here are very important for our cold spell. See paragraph 2 where it talks about CORE OF NEGATIVE ANOMALIES TRACKING ACROSS THE NRN ATLC APPEARS TOO PROGRESSIVE... This suggests that the models are being too quick to push low pressure across the atlantic towards the uk. Also paragraph 3 highlighting uncertainty. AFTER DAY 3... MODELS SHOW MEANINGFUL DIFFS WITH INDIVIDUAL SHRTWVS WITHIN THE NERN CONUS AND ERN PAC MEAN TROFS. HIGH UNCERTAINTY WITH THESE FEATURES... LIKELY NOT TO BE RESOLVED SATISFACTORILY UNTIL THE SHORT RANGE TIME FRAME... These shortwave features forming off the PV are important in relation to us, if the models are being too progressive then the scandi high is likely to get a better chance to build. The full discussions are available here. http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

Yes well spotted I was too busy obsessing over the temps! John what do you make of the model guidance in the discussions over at NOAA, heres the link. Not sure if you saw this earlier but some key issues that impact on us are discussed here. http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

Some ensembles for closer to home. Heres the Isle of Man ecm ensembles, thats a very large spread of solutions for an island location, to me it looks like its all over the place. http://www.ecmwf.int/products/d/sampler/ep...urope/page.html The operational goes from on the cold side of the ensembles to right at the top end of the mildest solutions still lots of colder solutions on offer.

Going back to the rule or often trend when one model is out of kilter with the others, what has happened to the ecm isnt really a sudden switch but its always over the last few days been very reluctant to jump on board. If the ecm was great and then suddenly imploded I would be more worried as we could say that its picked up on a new signal , however in this instance its always been the least wintry of all the major models. This simply seems to me that its modelling the push east of the PV differently and being too progressive, its also very reluctant to build heights over scandi aswell. Somehow I just cant see a complete capitulation by the ukmo and gfs but at worst a blended solution where the models meet halfway. Also not to gripe too much but I'm sure theres a correlation with lack of posts in here and the removal of the member names at the bottom of the page, is there no way of redirecting some of the resources to the main areas where most people are rather than just losing the members at the bottom of the page. I'm afraid once you get used to the normal lay out it seems distinctly different and not so good with out these, surely most people can put up with the site being a little slower so we can have the normal layout. So if any of the mods are viewing could you take this on board please and perhaps speak to Paul.

Well whilst that ecm continues to churn out these operational runs we cant ignore it as much as at present I'd like to nuke it! Theres alot of uncertainty regarding the upstream pattern as noted by NOAA in their discussions relating to shortwave features in relation to the PV over canada, perhaps we might see a blended solution come the time between the 3 major models. Here first is the NOAA discussions http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html Check out paragraph 3. However the ecm 00hrs run was a mild outlier for wed into thursday the crucial time in the models. http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html Everything is very volatile in the models and to be honest I wouldnt look past 72hrs.

Hi Steve hope you're having a good holiday. Yes that ecm sucks big time so far at 96hrs, the fax chart for wednesday is out and already dismisses the 72hrs ecm data so thats hopefully a good sign, but I agree that ecm is really beginning to get on my wick now!

I totally agree with you Dave. Asking people not to get a little excited about the messy but very interesting synoptics is a bit like shaking a bottle of champagne and then opening it and not expecting to get wet! My one hope is that all this model drama does end up with some people seeing some snow and then it would have been worth it! Its true we don't often see these types of synoptics in the models and given the dire winter so far its totally understandable that people are ramping. This is a glum free zone at the moment, any glum misery posts should be deleted!

I have so little confidence in any output past 72hrs that I've put on hold my order to SledgesRus! To be honest PP I don't think I've seen the models struggle so much as in the current outlook. IMO they're unsure of what happens over scandi and because of this all the output is all over the place.

Whatever the ecm, ukmo or gfs show is liable to change again on the next run, the amount of changes we've seen over the last few days is pretty amazing and shows that for some reason the models are really struggling with this pattern. I would really advise people not to look further than 72hrs until the models settle into some consistency, as soon as agreement is reached by all 3 major models then we can look a little further ahead, the thing is I have no idea when they will reach agreement!

Yes well not surprisingly the gfs and ukmo disagree at 120hrs! I'd agree though F1 starts at T-72hrs, we still really have no concrete idea whose going to get snow, its pretty amazing to have no confidence at all in any output past 72hrs but the models look ready to go into meltdown!

I agree with you Tamara, it is all a bit of a double edged sword! people want to see some snow which is totally understandable but the problem as you mentioned is this means that we're being attacked by that pesky mild atlantic air, how about we order snow then the cold air wins! its a shame we couldnt do that! if I had to I'd take my chances with an extension of the cold because we might then at least see snow that doesnt get washed away after a few hours, at the moment we dont know where this pattern could go and thats really turning the model watching into an absolute thriller! Does that make me sound sad, I think I'll get my anorak and go out for a walk to calm down!

Just seen the gfs 12hrs run. Has Tamara been meddling with the gfs supercomputer! What a great run but with the amount of changes over the last few days I'd say F1 is T-72. I need to go and lie down now!

I do hope whatever happens that theres not too much criticism of the ukmo as this really is one of the hardest set ups to forecast, if it was summer no one in here would care less where the rain is but as its snow its liable to cause much hysteria! Can I also just ask that even those who dont believe in prayer to start praying that the ecm was just a rogue run and had been infiltrated overnight by some mild rampers! and to return to the fold and be a little less miserable regarding the weeks snow prospects.

Afternoon John do I detect even a little ramp from yourself! I don't envy the ukmo at all this week as it looks a real nightmare to forecast. I must say though that the ukmo 120hrs raw data is a great chart its a shame that the ukmo have edged away from that in their fax charts. Lots of fun model watching though even though its a real thriller.

And as we have some time to fill heres the latest ukmo 48hrs model and the corresponding output upto the same time from the 00hrs run. UKMO 06hrs http://moe.met.fsu.edu/cgi-bin/ukmtc2.cgi?...&hour=048hr UKMO 00hrs http://moe.met.fsu.edu/cgi-bin/ukmtc2.cgi?...&hour=054hr The ukmo 06hrs has pressure slightly stronger to the north, its only a few millibars difference but this shows why I should get out more! As they say at a certain store, every little helps! The ukmo run this extra 48hr model twice a day for 06hrs and 18hrs. Normally out around 11am and 11pm.

Judging by the fax charts and the raw data it seems as if the ukmo have blended their own model with the ecm to reach a middle of the road view. Heres the raw data from the ukmo 108hrs and the fax chart for the same time. http://moe.met.fsu.edu/cgi-bin/ukmtc2.cgi?...&hour=108hr http://85.214.49.20/wz/pics/brack3a.gif Notice on the raw data the low near the sw as compared to the fax charts. So it looks like they have taken into account the ecm operational run but see enough in the ecm ensembles to suggest that the ecm is being too progressive.

Yes it is a worry why that ecm would be so awful this morning, it pushes that low in so quickly compared to the other models, the only support I can find for it is the gem at 96hrs, the gfs 00hrs ensembles didnt have one single member that backed it either so its all rather strange. At the moment there are 4 models against it and its own ensembles so being realistic it doesnt have much support, if its picked up a new signal then that would just sum up the winter so far! but its quite key how the ukmo havent backed this also if you're looking for the tiniest of signs about the trend for today the latest ukmo 48hr model slightly strengthens the ridge from the ne compared to the equivalent time from its 00hrs run, only by a couple of millibars but small differences earlier can make a big difference in such a knife edge pattern.

Some interesting news regarding todays ecm 00hrs run, we have the De Bilt ensembles for holland here and these show the ecm was a clear mild outlier on wednesday and into thursday as it pushes the low in too quickly, thereafter the ecm operational is always on the milder side of the ensemble members, the key here though is wednesday into thursday, given this I think we should ditch the ecm upto at least 96hrs, it has only one model (the gem) supporting its 96hrs chart and hardly any support from its ensemble members. http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

The latest ensembles show clearly the uncertainty with london for example having a spread of 10c on the 850s only 4 days out, the actual uncertainty begins as early as wednesday! just goes to show who would be brave enough to call whats going to happen from wednesday!

Thankfully the gfs this morning doesnt back that horror ecm 00hrs run, later on the real interest is whether that low can undercut the block rather than head ne at 132hrs. http://www.wetterzentrale.de/pics/Rtavn1321.html If we're to extend the cold spell this shortwave feature running off the main low needs to head eastwards and split from the main atlantic low and undercut the block, will be interesting to see if any of the ensembles go for this option.

The freebie ecm ensemble this morning is for the Isle of Man, the ecm is all over the place from as early as wednesday with a huge spread of ensemble members, however the ecm operational run looks like on the cold side of its members earlier and then one of the mildest options from late wednesday. http://www.ecmwf.int/products/d/sampler/ep...urope/page.html John Hammond on bbc weather just now said much colder with a chance of snow later in the week, from the hints so far I think the latest fax charts arent going to back the ecm which would be a big relief.

Pity the poor forecaster doing the countryfile weather today! what are they supposed to say well the weather for the week ahead is cold till tuesday then the screen goes blank! The ukmo do run a 48hr model for 06hrs and 18hrs on top of their normally twice daily 144hrs runs so perhaps this may help them a little. And also might they pay more attention than normal to the gfs 06hrs run seeing as they'll be desperate not to look too confused for countryfile. The only backing for the ecm this morning in terms of it being very progressive is the gem, all the other models do build stronger pressure to the east and ne, perhaps we might end up today with an ecm/ukmo/gfs combo with extra cheese and reliDoh a dumb swear filter got the better of me

Just to highlight the uncertainty here are the 72hr charts for the big 3 models. GFS http://www.wetterzentrale.de/pics/Rtavn721.html ECM http://www.wetterzentrale.de/pics/Recm721.html UKMO http://moe.met.fsu.edu/cgi-bin/ukmtc2.cgi?...&hour=072hr Also the fax chart for the same time. http://85.214.49.20/wz/pics/brack2.gif The key difference in the ukmo and gfs versus the ecm is the better build of pressure to the ne. As I mentioned earlier about the radio 4 forecast at 7.55am I dont think I've ever heard Rob McElwee sound so uncertain regarding events from midweek. This is certainly turning into one of biggest model dramas ever seen on here, I'll be happy with either the gfs or ukmo to be right, fingers crossed that the ecm ditch their awful 00hrs run and get into the spirit of things this evening.

Its a pretty amazing state of affairs when the models dont even agree at T-72hrs! the ecm disagrees with the ukmo from as early as 72hrs and I cant find a single ensemble member in the GEFS that backs the ecm at 96hrs! however we cant discount this run because its awful we're going to have to wait and see what happens later. Just heard the radio 4 weather with Rob McElwee said colder mon and tue chance of snow from around midweek for wales central and southern england but highlighted the uncertainty, actually he sounded like the ukmo are as in the dark about this as us on here.