LomondSnowstorm

Aye, the initial analogues are a bit mixed to be honest - ENSO signal is fairly muted, QBO is westerly which is generally not a great sign although combined with an, albeit low amplitude, solar maximum does increase our SSW likelihood, and while the AAM tendency has been negative until fairly recently we're seeing a decent uptick in Mountain torque which is forcing it positive which, combined with some Wave 1 activity, could filter through to some more interesting conditions later in the month. On the other hand, we are seeing the Polar vortex building up quite strongly from the top of the strat downwards which suggests that we may not be done with the stormy weather for a good few weeks yet, although I'm expecting at least one decent northerly outbreak in the next 4 weeks to come from it. We've had a decent gain of Eurasian snow cover so far, and sea ice remains below the long term average, which should both aid the potential for high level blocking in the coming months. Overall, I'd say we're looking at a winter which is average to below average, with rainfall likely above average (particularly to begin with) and with temperatures generally colder in the second half than the first half (analogues point to a January/early February SSW). However, the gamechanger would be if we could develop a December 2009 scenario where localised wavebreaking over Greenland leads to an early breakdown of the vortex, and we all know where that lead us. I'd say odds are currently against that but I wouldn't completely rule it out, and of course nor is a warming event later on in the winter a stick on either.

I take the point they make about the regional impact being worse because wind events are more rare in southern England but even so, at the moment it doesn't look like being *that* severe even in the context of southern England. It's noteworthy of course, but as ever the media do love to overhype weather stories because they sell newspapers very well and even moreso if it actually affects the area where the majority of journalists writing the stories live and work. I don't particularly blame the MO, because they do have a duty to warn people and it's very easy for what they're saying to be misinterpreted by scientifically illiterate types who don't know think there's a difference between a 72mph gust and Hurricane Katrina (for example), but they should be careful that they don't end up painting a picture of a 'UK-wide' storm when in fact less than 1/4 of the landmass and no more than about 1/3 of the population are likely to experience anything other than standard October weather. Of course, this time next year we (hopefully)may not have any right to quibble about headlined 'UK-wide storms' not really affecting Scotland but that's a rather different issue

NAE 6Z is a slight 'upgrade' on the wind, with 30 knots sustained wind around Edinburgh/East Lothian by evening: Fortunately, however, the main impact overnight into tomorrow for the far south of England looks relatively benign compared to what might have been, with the worst of the winds out in the Channel and, for us, it's likely to be a fairly calm night:

Interestingly the 'downgrade' actually upgrades the wind speed for here on Monday, although 20mph sustained winds is hardly anything to write home about, and as ever the GFS is staggering in its ability to get vital details at short range very badly wrong even when every other model goes against it - god knows we saw it a few times last year. It could be a potentially nasty storm for the very far south, particularly given how unprepared they seem to be for adverse weather in spite of days of hype, but even without the 18Z nonsense it doesn't look like being particularly destructive for the vast majority of the landmass of the British Isles. Still, I hope those who are in the firing line are prepared for it, whether they be on the south coast of England or in Northeast France, the Benelux and the German/Danish coast. The hype may be irritating and completely ignore the reality of the numerous storms to hit Scotland which were of greater intensity than this one but it does look as though it might be quite nasty for some folk. Anyway, here are the NAE and GFS 18Z side by side at +36, just for the hilarity of it: NAE: GFS:

Update on the winter forecast - I've started on the process of creating my composite chart for the closest analogues to the winter ahead and I've so far whittled it down to 10 years, and hopefully down to 5-6 once I look at other variables. The signal thus far is pretty weak it must be said but has the look of a late winter to me and there are some decently below average winters in the mix too. At the moment I' plump for maybe 55-45 on colder than average over milder but as with 2011/12 (which never quite pulled it off) or one of my other preliminary analogue years of 2008-09 it may require some pretty drastic stratospheric forcing to unseat what looks like potentially a more significant Greenland centred PV early winter than we've seen in a while. For Scotland of course a strong PV could work in our favour and open the door to Polar or even Arctic northwesterlies, especially with the more southerly tracking jet of recent years, but it can also lead to more typical mild Atlantic driven weather. Anyway, I'll keep you posted and I'm hoping to have a full forecast done by the month's end.

January 1968, one of my grandad's favourite weather stories of when he tried for 3 hours to get from Bankfoot to his work in Kirkcaldy before turning back because every single road was either closed or impassible due to fallen trees. http://en.wikipedia.org/wiki/1968_Scotland_storm 70,000 houses damaged, 300 destroyed and 9 dead in Glasgow alone, with gusts widely over 100mph (although we did reach 102mph that on the January 2nd 2012 storm that BMW remembers on the Tay Bridge, I believe). The charts are deceptively benign relative to the actual conditions, probably because, as with most of the highest impact storms, the deepening occured very rapidly from midnight to 6am and also because the wind vector aligned with the central belt corridor, although whether or not there was an actual sting jet associated with it as there likely was with 'Bawbag' and January 2nd 2012 is very hard to determine.

Broadly speaking, there's nothing *that* interesting in the current charts. The ECM looks a bit more promising than the GFS, with a decent northwesterly and uppers getting sub 0C if not quite sub -5C but mostly it looks to be a fairly mobile pattern, with the only sign of heights building in a sustained way being to the south rather than the north, which doesn't bode well for any sustained cold shots, but hey, it's extremely early days yet. Anyway, this is the ECM northerly toppler: Mean heights for the Northern Hemisphere: The 8-14 NH anomaly, with the first signs of the Polar Vortex revving up and low heights dominating the region to our northwest (better hope that clears off at some point or it might not be much fun, although I suspect it won't be a permanent feature) Interestingly this seems to be driven by a fairly early predicted MJO event, which the GFS makes a far bigger deal of than the other models: compared to the ECM which has a, perhaps more realistic, lower amplitude phase 1: and the UKMO which actually pegs it back into phase 8. The anomaly chart looks very similar to the October phase 1 composite:

Great minds think alike, I got an email about this from my Meteorology lecturer so I'll see yourself and maybe some other east-central based forum regulars there as well Things are shaping up nicely for this winter (or at least they were until Jonathan Powell decided to start an ill informed early rampede worthy of the MT ) and if you haven't already you should head over to the shiny new 2013/14 strat thread where Chiono has started with a fantastic explanation of the relevance of the strat along with his two cents on where this winter is likely to head. He and GP were very early in picking up the early January SSW last winter and he's also noted a tendency among his composites for 'split' (a la February 2009) SSWs in late January to early February. I'm personally hedging my bets on composites until near the end of the month when we can get a read for the all important October eurasian snow cover gain. So far it's looking fairly promising, with the snow cover anomaly positive across great swathes of the northern Eurasian continent and has expanded westwards quite rapidly since the start of the month, with even a somewhat unseasonable snowfall across southern Bavaria, Austria and Switzerland (although snowfall in the Alps in October isn't that much of a rarity the depth and altitude it reached were rather impressive).

A little prelude to the proper winter season this week, with a glancing blow from a northerly bringing with it some sub 0C uppers with just the hint of some wintry potential for ground above around 700m in the north and northwest: Looks even better on the ECM with the first -5C isotherm of the 2013/14 season popping up around the Northwest Highlands at +96 (Thursday midday): A classic winter transition to follow too, with a 'toppler' easterly before heights transfer to mid latitudes for what in practice will be a decent period of weather for most, with a few showers here and there are a bit more persistent North Sea clag by the end of the week for the southeast in particular, with the promise of high ground generally fading by the weekend as we introduce a continental airmass. However, generally speaking, bright, cool with temperatures maxing out around 10-11C and with the odd touch of morning frost, particularly away from exposed coasts and where skies clear for longest. I'm currently pretty busy standing to become an NUS Scotland delegate at the uni so I probably won't be around that much this week (barring the onset of an historically early massive upgrade and a subsequent rampede/TOORP cycle, which would be far more critical than my fledgling student politics career) but I'll certainly be back before the end of the month when maybe I'll even have an initial Winter Forecast for you all... LS

10.8C, mild start, cooling down slowly towards average as the month progresses.

Yep, cold enough with significantly frequent snowfall for a good period of skiing, along with the added bonus (for them) of relatively clear roads from the central belt northwards due to the average temperatures. Cold zonality is usually pretty good for Scotland in December because of the latitude, low solar insolation and the westerly vector countering the wishbone effect that affects a great many of us when the wind direction is more northerly: This was the first snowfall, which I remember most of us did pretty well out of, and in spite of uppers only around -4C we had frequent moderate snowfalls which brought temporary but reasonably good quality cover to the central belt with it piling up on the mountains, which lasted even through the very mild spell around Christmas Day when temperatures were around 14-15C. That was also the month that brought 'Hurricane Bawbag', followed by another vicious storm on I believe the 3rd January. The second half, while colder, was far less eventful with the blocking too far south for any significant cold or snow, and actually the best snowfall of 2011/12 generally, for the north and east of Scotland at least, fell on the 3rd April.

Yeah, that's an interesting way of looking at it but you're right enough, some of the same factors at work building up the initial snow cover required to in turn aid the blocking setup. I also think of it as increasing the 'resolution' of the image i.e. pinpointing where the blocking is most likely to set up. At the moment I'd say it isn't shaping up quite as nicely as last year was at this point but there's still more than enough potential there for some decent cold, which is a far cry from the pre-2008/09 days.

The very long range raw model output for temperature anomalies is not worht taking all that seriously unless there is a very clear and coherent signal. They're fun to look at (although maybe not ones which are quite so filled with reds) but as we saw last winter their ability to handle major events, particularly the winter-specific factor of the stratosphere and potential SSWs, is pretty limited. The Met Office long range guidance was reasonable from what we heard from Ian and the GloSea5 model was actually able to pick up the SSW before it hit but even then it was well into December before that model picked up on it, well after our resident strat experts accurately picked up on the possibilities aloft for early January. My view is that it's still too early to make many firm judgements on the winter ahead because so much depends on how things like NH snow cover set up in the coming 6-8 weeks.

Had a decent thunderstorm here, a few strikes of lightning which were fairly close by. Sunny at the moment but the potential for more through the day remains, particularly in this neck of the woods, although they look to be fairly disorganised so it will be pretty hit and miss, the summer equivalent of a convective easterly 'toppler':

Certainly a lot of rain here and lightning visible every minute or so in both directions but with minimal thunder (although having said that there is a bit more around now). A fair amount of cloud to cloud lightning but I think most of it isn't in our immediate vicinity. Still hope for Thursday, CAPE potentially a bit more favourable than even today so it'll be worth keeping an eye on certainly: Thereafter a continuing risk of storms, though perhaps less severe, as low heights to the southwest continue to slowly build in and plumes of warmer upper air move up from the continent: edit: it really seems to be overhead now, about 3-4 seconds between a big crack and a loud rumble of thunder.

Hello everyone, it's been far too long since I last stopped in, I think probably during that exceptionally cold and easterly dominated spring which feels like years ago. Maximum temperature on the weather station this year is the highest I've seen since we bought it in 2009 at 31.7C on the 9th July closely followed by 31.6C when I was away on holiday on the 19th (which corroborates pretty reasonably with the 29.7C recorded at Cupar on the same day, the highest temperature in Scotland). Fortunately/unfortunately I've been in marginally cooler but equally sunny climes for most of the month, touring around Germany and Austria by train. We got a typical Alpine thunderstorm the day before our flight back in St Anton which cooled things down but otherwise it was spectacular weather for sightseeing and a bit of hillwalking. I'm also in the process of moving into my new flat on Chapel Street which is a sloth's dream - a 2 minute walk to lectures or the bus out to KB and within 10 minutes of all the food and alcohol vendors you could ever need Anyway, the inevitable transition to cooler and more typically Scottish weather might be quite a bit of fun if you like downpours and thunderstorms, as I do on occasion, with Tuesday afternoon/evening in the south and Thursday for most of the country holding the most convective potential as the Atlantic finally manages to break down the limpet high which has graced our latitude with its presence in the last few weeks. This change, which today's cooler, cloudier respite from the east/northeast hinted at, comes courtesy of a flip to a 2012-esque phase of the NAO i.e. negative: Some settled and potentially still pretty warm weather to come still, moreso in the northeast where the high will exert significant influence through the week still and where the battleground plumes responsible for the thundery weather just heading into the southwest will be found, but generally the trend is towards a lowering of heights, an increase in precipitation (from effectively 0) and a lowering of temperatures from the giddy heights of last week. LS

This is a bit late but congratulations to Lorenzo, glad you didn't have to dig yourself out to get to the hospital as you might have a week or two ago. Lovely outside now, still well below average but in the sun it feels pretty reasonable. At least the second half of winter has been relatively dry NL, hopefully that continues for the next few months but with increased temperature values and a lessening of the easterly winds.

It isn't up yet, was provisionally at 1.6C but I think it got pushed down a notch with the very low minima in the last few days: http://www.metoffice.gov.uk/pub/data/weather/uk/climate/datasets/Tmean/ranked/Scotland.txt Not quite as cold as I'd maybe hoped but still an exceptional month, moreso for the CET zone.

Another snowy evening/morning in Edinburgh toon, a shame we couldn't retain cover during the day but still easily the most enjoyable two week spell of the winter period.

All the best Stewart, your research and forecasting methods were ahead of their time and I feel very fortunate to have been able to learn so much from you. The style of your posts was always well mannered, well reasoned and entertaining with a healthy amount of geekiness mixed in and I liked that even when your forecasts didn't go exactly to plan you evaluated them fairly and used them to further improve your forecasts in the future, the very essence of scientific enquiry.

I'm back in Fife at the moment so could be very hit and miss here - some parts perhaps getting more than the Borders even as it stalls and intensifies but with other parts missing out. -0.5C with a fresh dusting so going to be really fun if we do get a direct hit.

PG, if you're still up look outside - lying snow even on the roads in Edinburgh, on the 27th March! Incredible snow shower hit about 1am, very heavy, covering on all surfaces. More to come overnight by the looks of the radar - some really intense showers out there in the North Sea.

Similarities to the January cold spell there, though if you look at the temperature curve for all data you'll notice that this is probably the coldest spell of the winter so far for Edinburgh.

You spoke too soon, some really pretty heavy light snow on now here, a dusting on the ground, just about, with visibility dropping for the first time in about a week. The most depressing thing about this - imagine how much we could've had in the last 5 days if it'd been just slightly heavier.

Precisely, so we shouldn't vilify anyone on the basis of their preferred weather. My view is that we only live once and that I'd like to experience as much of what nature can offer as possible, including heatwaves, blizzards, storms, thunderstorms, aurora etc. How dull would it be if it was mild all the time?