nick sussex

Morning all The gfs and ukmo both agree on pressure building to the east and these two charts make interesting reading as we see a shortwave develop and run se towards france, the ukmo is the best as this develops this feature much more than the gfs, there could be some significant snow as this clears se wards.Where exactly depends on the track of this, we wont know till much nearer the time. http://www.wetterzentrale.de/pics/Rtavn1201.html http://www.wetterzentrale.de/pics/Rukm1201.html However we've seen so many changes over the last few days it would be premature to bank on this feature , where it tracks is still liable to change. The longer term sees a low try and get in from the atlantic but given the volatile nature of the models I wouldnt look any further than 96hrs. But it was of course too good to be true to have good news all round, the ecm this morning shunts the atlantic in by 96hrs! pretty amazing differences at only 96hrs. http://www.ecmwf.int/products/forecasts/d/...0400!!/ This morning its the gfs, ukmo, no gaps, gme against the ecm and gem! that ecm chart is a worry. Lets hope the ecm hast now picked up on another signal as the ecm is awful, we'll know what the ukmo think when they update their fax charts, the use the ecm ensembles to see how much support their operational run has, if the ukmo dont modify their data and stick with their own model that would be a good sign, all this model drama is getting too much for me, I'm suffering from nervous exhaustion! lol

Just for a laugh even the no gaps 18hrs run at 120hrs looks like its going to back the gfs 18hrs run! :lol: http://www.meteociel.fr/modeles/nogapse_ca...=120&mode=0 So tonight we have two cannon fodder models the gme and looks like the no gaps backing events at 120hrs! Lets hope the others come on board tomorrow.I know people would like to see some snow but if that means the atlantic rolls in afterwards and washes it away then why have all that trauma! If we get a colder source of air at least this will increase chances for when the next atlantic low tries to get in, thats if it does!

The gfs 18hrs run certainly throws the outlook into even more confusion! this run actually backs the gme 12hrs run. I wouldnt dismiss this run because its the 18hrs run and this is plausible given the trend to build pressure to the east, this really is not that much of a surprise. Of course if this verifies it means no real snow event for wed/thurs and any snow is more likely to skirt with western areas if the front makes it that far. There is of course the possibility of another snow event later, the key is if we are to get this build of pressure that it doesnt sink so as when the next atlantic low tries to get in that we can see this undercut colder air being pulled in from the east and se. We'll have to wait to see what the other models do in the morning as the gfs has been at odds with the ukmo and ecm in terms of the type of breakdown shown in earlier runs, it would be a pretty sensational turn of events if all this model drama ends up in a scandi high. Of course the other models might not back this and the gfs might ditch this in the morning, the model drama continues, this is all very exhausting!

Yes but they already have feet of snow and flurries over there doesnt mean the one snowflake an hour that it does here!

Well JS if you fancy some proper winter weather then how about this for a forecast, this is north of Toronto where my friends live. Now thats what I call cold! http://www.cbc.ca/weather/conditions.jsp?station=WRK

Thats really annoying and has happened to me a few times. The most notorious was that 1996 event when I was living in London and the front stalled to the west of london, I was at university at the time and a couple of friends who lived out in the midlands rang to tell me that they were snowbound! again on that occasion the front was supposed to make slow progress eastwards but decided to stop and retreat westwards! these things can happen when pressure is trying to build to the east, I'm not saying that will happen here but the weather can and does surprise.

Evening Phil yes the gfs still progs some cold air at the surface but the problem is the surface flow, theres quite a lot of difference between 850s of say for example -5 with a continental flow and exactly the same value off the atlantic, the modification that is likely off the atlantic diminishes chances for snow. We often see snow events even when the 850s are not that much below freezing if the surface flow is drawn from the east because of the lower dewpoints and less modification. I'd say for next week its crucial that the fronts are orientated more nw/se and the surface flow is as close to easterly as possible, another factor is the wind, less wind and heavy precip better evaporative cooling which could make a difference. Because we dont have access to really cold air alot of things have to go right, for more northern areas theres more margin for error. I would also add that regardless of what the synoptics show today people shouldnt be banking on snow, or worry too much about their location, one day one area might seem favoured the next day this might switch. This is all still evolving and whenever you have high pressure to the east trying to build then really be very wary of any model output until very close to the time.

I think sometimes too much is made of the 850s when in reality its the culmination of this with many other factors like thickness levels and dew points etc that determine if its going to be snow or rain. For example snow can fall with 850s of just below freezing if other factors are positive, we've seen many times snow events with a surface flow ahead of the front from the east or se because as a rule this will produce better other factor conditions. The one thing I would say is that its crucial for the proposed breakdown next week that the surface flow ahead of the front is no worse than se or more preferably easterly, the latter would more than likely produce the best chances for more areas.

Yes that could be a problem with eastern coastal regions in particular with the surface flow ahead of the front being a likely east to se bringing those dew points up. Going back to the possibilities of a staller, its nigh on impossible to forecast this until almost the day, although the ukmo will normally drop the odd hint if they think theres a chance. Theres also the possibility that the front doesnt get any further than the west and weakens as pressure builds from the east. I certainly wouldnt like to be in the ukmo this week, what a difficult forecast to make. Going back to the longer term an onslaught of the atlantic looks likely with a deep trough running across the atlantic but exactly where the lows track is in a little more doubt because of pressure building to the north again esp over scandi.It will be interesting to see if these positive anomalies continue to grow as this could take the track of the lows further south. Heres the mean height comparisons. http://www.meteo.psu.edu/~gadomski/ECMWF_12z/hgtcomp.html

Okay lets forget about the football! the problem with the proposed set up next week is that its marginal for areas away from the north, as you said with a strong scandi high and lots of cold air embedded at the surface this helps enormously to deliver to the widest area if fronts come up against this block. Next week although we will get some colder air its not cold enough to give a better margin for error. But its one of those situations that can often surprise aswell as disappoint in equal measure, the problem is that we dont have a concrete idea of the exact breakdown and we wont know this till much nearer the time.

Its a shame that we cant have a snow event that effects everyone and that way theres not people left feeling shortchanged. Unfortunately I cant remember when we had snow that affected a large area of the country. As ever its a bit like supporting a football team with each side cheering on the synoptics that could deliver them some snow. Perhaps as we have time before the next gfs run we could discuss what synoptics will be good for certain areas, on one proviso that a riot doesnt break out in here!

Nice to see theres so much positive energy in the thread this evening! I'm not a mod but for heavens sake if people don't like the thread no ones got them at gunpoint forcing them to take part! This is supposed to be a happy forum, why does there have to be so much sniping! Now back to the models it all looks very interesting with still no clearcut idea of exactly how the breakdown will take place and the longer term prospects look even more uncertain. Anyway lets just enjoy the model ride and hope it has a happy snowy ending for some people.

Some interest in one of the cannon fodder models the GME. It looks like the first shortwave misses here but instead we get a scandi high instead! :lol: http://www.wetter.com/home/img/sat/gme_cl_...2031200_096.gif http://www.wetter.com/home/img/sat/gme_cl_...2031200_120.gif http://www.wetter.com/home/img/sat/gme_cl_...2031200_144.gif http://www.wetter.com/home/img/sat/gme_cl_...2031200_168.gif The GME is often thought of as the poor mans ECM but if theres one model that normally gives a little hint to the ecm its this one. I wonder what that will show, oh the drama! I'm not ramping but that 168hr chart is the perfect battle scenario for significant snow, how far east it would come is anyones guess and anyway I just thought I'd throw this into the mix seeing as we have a quiet interlude before the much awaited ECM comes out.

I agree with you PP, seeing as the tax payers are basically paying their salary why does everything have to be shrouded in secrecy. I think it maybe to do with finances as many organisations pay for their views. Whatever anyone says about the gfs they're very generous with their data and deserve a pat on the back for not being so stingy.

The gfs and ukmo still disagree on how the breakdown will occur, so still no way at this present time of knowing whose in for some snow. GFS http://www.wetterzentrale.de/pics/Rtavn1201.html UKMO http://www.wetterzentrale.de/pics/Rukm1201.html I suppose the area with the greatest margin for error in terms of still getting snow would be northern areas.

Afternoon all Well it looks like everyones a bit happier than after the 06hrs run. However everyone knows I like to ramp but the building of pressure to the east is still liable to cause problems for the models, its very difficult for them to pinpoint how far east the front will move and its likely to weaken as it comes up against the high pressure to the east. I know its frustrating but really dont get your hopes up too much for snow until within 48hrs as these types of synoptics lend themselves to being a complete nightmare to forecast. We still have to see what the other models make of this, theres bound to be some disagreement.

Only another 3 hours to the next gfs run! I need to get out more! I'm sure this place will be very busy tonight seeing as we might be approaching a crucial fork in the road, one sign says cold then snowy breakdown for some then back to average, the other says cold then snowy breakdown then scandi high lows tracking more southerly and loads of fun for us, of course theres always the cold then more damp squib breakdown with much less snow for most and then lows edging further north as the pressure rise to the ne is blown away by the atlantic. So where will we be this evening? its bite your finger nails time, I think I'll be viewing future model runs from behind the sofa! Could be a pivotal few days coming up now! See you all later.

The ensembles look strange, given the pattern you would expect to see a bigger scatter. GP mentioned this type of ensemble pattern the other day in the gfs as something it does before we see a big scatter in the following run as currently it really doesnt no where to go later in the week, I would say that we may see some big changes over the next few runs. Look how flat the mean line is in the ensembles for aberdeen, it may seem strange looking at those ensembles to suggest huge uncertainty but this pattern correlates often with a switch in model output over the following runs.

Well the JMA normally sits in my cannon fodder model section! and regardless that it did show a pressure rise its now jumped ship here. The actual mechanics behind its easterly was different though to what is being progged by the possibilites shown in the ecm and gfs, though I'd take any easterly how ever it appears!

The general theme from the ensembles is for a train of lows heading in from the atlantic on a more southerly track than we've become used to over the winter so far. This is all high risk though as we would need to see pressure remain strong to the north and ne to keep us close to the cold air and allow for some snow and a general colder theme. The nirvana for us in the uk is for the right set up that allows for enough colder air to get into the mix whilst still seeing the lows close enough to deliver significant snow, however if pressure falls to the north and ne we will end up on the milder side of all the fun. Today is the first time we've seen two operational runs go for more significant pressure rises to the ne these being the ecm and gfs, its from now that we need to look at the trend, will pressure continue to build and take the lows even further south and bring us a decent cold spell or will the models keep us in a halfway house or conversely blow the block away. Actually I should also add the ukmo here judging by the fax chart for 132hrs. http://85.214.49.20/wz/pics/brack4a.gif This is an interesting chart in that if pressure continues to rise to the ne then we may see the low split from the PV to the sw of greenland and that bump of high pressure to our sw ridge north and basically force the low back sewards with ridging from the east backing west over the low centred over the uk.

Regarding the 00hrs ecm run some interest in the De Bilt ensembles for the time of the breakdown, the ecm operational was one of the mildest options for next wed/thursday suggesting that we may see a slightly improved 12hrs run. http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html It looks like until we see the models resolve what happens to pressure over scandi then all model output past 96hrs is likely to remain very volatile.

Morning Snowmaiden well this run actually trends towards the ecm 00hrs run, you never know we might still get a decent breakdown and then a scandi high! that was a mini ramp! this is all exciting stuff, I have no idea where we'll end up but I would take the crappier breakdown if it means a better longer term pattern.

You have to laugh! it looks like chaos is set to break out again in the models as pressure wants to ridge over those lows from the east. Lets look at the bigger picture here, do we want a snow to rain event and then the atlantic back in or do we want a longer lasting cold spell? I know people might be a bit disappointed about the breakdown but things are still volatile even before 96hrs. Confusion is always a good sign, who would like to make a forecast for next week, you'd be pretty brave!

Fair enough. :lol: Even in Iceland Steve M cant resist seeing whats going on in here, lets hope hes having a nice holiday and seeing some snow. :lol:

Morning Richard nice to see you're as optimistic as usual! :lol: The ecm might be zonal later but we've seen so many changes this week already, the surface scandi high which has now appeared and wasnt progged by any model only a few days ago, I'm not saying that we're going to be in a biting easterly I'm just highlighting that the models keep throwing in different variables. This relentless negativity by yourself no matter what the charts show is very perplexing, I know you like the snow as you are a skier, so what exactly is going on here? Fair enough highlight the problems but for heavens sake take a realistic view of the overall model output, we're all aware that things do and often implode in the uk regarding winter synoptics, I've often shared a good laugh with you in here but I just find at the moment you're determined to bring everyone down. The problem is Richard that you might not realize this but people are beginning to think that you just want any cold synoptics to implode so you can come in here and laud it over everyone, that isnt model watching thats just showing a meanness of spirit! So please can we have the old Richard back who occasionally brought some humour and lightheartedness to the room rather than constant gloom.