nick sussex

I think this snow event is more unpredictable than the one over the last weekend. The latter had a front trying to displace the colder air, here as this front edges east its being met by some colder uppers moving west from the continent, I think snow amounts forecast could be much more prone to error.

Back to the snow event, its complicated as some colder upper air is heading west and as it engages that front this is when the precip is likely to increase in intensity.

I think what might help regarding snow chances is the light winds, for this reason the marginality might be reserved for the immediate coast line. The upper air temps are actually quite good and the surface flow looks somewhere between south and se. The latest NAE will be out shortly so that should give a better idea, still alot of uncertainty regarding where the main snow risk will be.

The one I can remember was called Magic with Anthony Hopkins, not a bad film quite creepy but can't think of a B&W film.

I think they're updating that at 4pm to include Pyrenees Atlantique and parts of the Midi P, towards Biarritz they're expecting snow then rain which could be a nightmare with that falling onto frozen surfaces. Still some uncertainty regarding the eastwards extent of the snow, here its expected to remain as snow but to be honest if theres a threat of freezing rain I'd rather the whole thing just avoided me altogether. As much as I love snow I'd rather lose out and not risk the freezing rain and inevitable power cuts! friends over in the Var had 25cms of snow the other day, which brought trees down onto power lines and left them without electricity with temps down to -10c! Have to say I've found Meteo France to be poor recently with their quelques flocons forecast on two occasions in recent days turning into heavy snow! of course I'm not complaining but the UKMO are far better IMO. Anyway bonne chance avec la neige demain.

Yes thats a very good point and could be an issue even here in sw France, the same system expected to effect the UK is forecast to slip south into Iberia, running through this region, still some uncertainty with where the snow and rain divide will be. At the moment its expected to be further west than me but could still change. The temperatures have been exceptionally cold even for this region, of course all this dense cold over France is good news for the snow chances in the UK, the surface flow looks to be southerly ahead of the precip and this should pull in some low dew points. Still wondering whether there might be some intensification of that precip as that shortwave hits the Channel so perhaps areas just inland to the east of that could get some benefit if that occured.

Bitterly cold here current temperature -6.8c, snowing and this comes off an overnight low of -8, yesterday didn't get above -2.

I think a positive out of the weekend is that its not like one of those deep lows moving up with lots of very mild sw winds ready to move in and wash away the snow. The air behind the front is still relatively cold and if skies clear temps should still slip down to freezing.

Very cold here, some light snow fell during the night but even under cloudy skies the temperature dropped to -6! It looks like some even colder upper air has headed in as the temperature has now dropped to -7. Certainly when I was living in the UK I don't remember many days like today which really feels very Canadian!

You know its cold when snow is falling in Bilbao and Santander in northern Spain! It's been the coldest day here since the winter of 2009/2010, top temperature scraped upto -3c, snow started falling this morning and has continued on and off throughout the day, what was great about this snow was the powdery nature and not that horrible wet stuff thats a pain to shovel!

Currently -4c, snowing but that powdery dry snow, first snow of the winter down here in the valley.

The last week in the models has had more twists than an Agatha Christie novel with the Siberian high causing chaos in the models and this shows little sign of easing up as we head towards the weekend. Certainly not a time for making concrete predictions about who gets snow and who ends up in the frustrating rain or dry zone! The modelling of these battleground scenarios is the poorest in terms of detail, if you think about 100 miles on a global scale its nothing but this makes a big difference when you're dealing with the expected weekend set up. It probably won't be until 24hrs before the event that we'll have a more narrowed down area at risk and even on the day this will still likely have some margin for error.

Who needs model output, just come in here and see how many pages the thread has extended to, I left to go out at page 8 and came back to see its upto page 13! I sort of knew then it wasn't just 5 pages of toys out of prams posts! I think these models should be sued for cruelty to cold lovers, the GFS 06hrs run picks up on a trend hinted at by both the ECM and UKMO, typically they've now dropped this! This is really the only quick way to cold as the other option is that slow moving trough over the UK and waiting for that to eject some energy south eastwards under the block, I'd advise people to not get too excited yet as we've been here before countless times over the last few weeks. If the others go with this tonight then there may finally be light at the end of the tunnel but thats still a big IF!

The ECM ensemble maps are out: http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2009112700!!/ A few members show a little hope with a better orientation of the trough, some have this a little further to the sw, really its upto this trough now in terms of the easterly, unless you get it to send some energy se'wards at the 168hrs timeframe then its going to take much longer. And thats if the Russian high is still orientated favourably by that point, we'll have to wait and see what happens but overall not the best starts to the day for those wanting to see a snowflake.

Oh dear after the operational output I was hoping for some better news in here! I think that would sum up the winter, the one place you don't want it to displace to it goes! of course the variance gives some hope but overall my optimism is beginning to wane.

LOL! Are you still wheeling those CFC charts out! You know my thoughts on them, I suppose just one month ahead might be okay in terms of trend but that just shows average anyway. I can see how an easterly could occur but I'm bored now! Especially as the implication is that trough will just sit there for a while spiralling around as we wait for it to find a life and then eject some energy se'wards. Give me the ECM 168hrs about 300 miles further west with a negatively tilted trough and I might be less bored!

Todays operational output should be packaged and sold as a cure for insomnia! The ECM at 168hrs at least has the Russian high orientated favourably but low pressure is reluctant to send any energy se under the block, apart from that the GFS does what you don't want and ridges the Azores high to meet up with the Russian high and once that happens energy runs over the top. The UKMO ditches even that colder blip it had on its fax chart last night at 120hrs, looking at the output theres concrete agreement for troughing sat over the UK, I won't bore everyone with the good and bad regarding tilting of that, just see my previous posts from yesterday! If its going to deliver an end result in terms of cold then its going to be a long drawn out process , we may get there eventually but I suspect patience is wearing very thin now. The eternal pot of gold at the end of the rainbow sums up this winter as a whole, the straw clutch team is on emergency standby waiting to see whether any of the ECM ensembles dig that trough further south at 168hrs and allow the ridge to come over the top!

Yes can we just get on with this and get the show on the road! I'm really losing patience with this winter and don't feel like watching that trough sit over the UK and decide whether it wants to eject some energy se'wards. Especially as it didn't have the decency to start off negatively tilted! I promise thats the last of my negative tilted troughing talk until tomorrow!

The upstream pattern is expected to amplify and NOAA preferred the more amplified solutions aswell as this the low is negatively tilted and should at least be delivering some WAA into Greenland. If the models have overblown that low then theres a better chance you'd get some disruption to it even if it still manages to get to the UK by then it would be more negatively tilted and better able to eject energy se'wards, as for the GFS 18hrs it makes a hard slog of bringing the Russian high in because it throws a shortwave north into Scandi off the main trough thereby delaying the westwards push of the high, without that shortwave the low would have already been yesterdays news and the easterly would be in much earlier. I don't want to flog a dead horse but its essential to get the negative tilt this makes any easterly much easier to attain.

You'd look at this fax chart and think the real cold was very close but the models want to drag the drama out with that troughing over the UK after this point.

I'd like to explain why the ECM at 240hrs is fine and that this has a good chance of delivering an easterly: The PV is elongated north/south this is not like the previous weeks, the base of the PV is likely to eject energy se'wards and the top of the PV is likely to pull nw as this happens. This is a good chart taken at face value especially as you have the Iberian low to help support the ridge initially, I would be surprised if the extended ECM ensembles don't show some very cold options for De Bilt, those ensembles are much more important in viewing an easterly trend than any other pattern that we see in the UK. Remember the ECM gets to a good chart even with a poorly tilted initial trough and so things may improve further if the initial trough is further west and negatively tilted.

The ECM actually gives me a bit more optimism, even with a poorly tilted trough it still manages to stick some energy se into Iberia and people shouldn't panic if a piece of the PV appears over western Greenland. Follow the output in the NH perspective where will the energy go from that PV? In terms of the UKMO further outlook theres no way this run diminishes the odds of some much colder weather,

Hard to know what to make of this run, but regardless I still think its to the ne that any pressure rises are going to come from. The Canadian high can amplify the upstream pattern and even with a strong looking segment of the PV if you get enough dig south then the jet should bounce ne in the Atlantic. I just can't see a Greenland high happening initially, the first stage has to be from the east or ne and we do see that Iberian low which is a good thing to support any ridge.

Regardless of the earlier differences the end result looks like the trough over the UK. And from there its going to be whether the high to the east can win the battle by eventually sending this packing, just signs on the ECM 168hrs of some forcing on that trough, note the shortwave developing on its southern flank. Will this disrupt sending some energy se'wards.

Last night the ECM was the first model to go with this suggestion: All the output has now followed with this trend so I'd pay particular attention to what it does this evening at around 120 to 144hrs.