Evo

Looks like the real heavy stuff is over in the Channel Isles. http://www.meteox.com/gmapstatic.aspx?zoom=6&type=zoom&x=148&y=262 Jersey is now SNOCLO. [The airport is shut due to the weather]

The 1620 METAR for Jersey had rain, snow and ice pellets. Nice.

Think you may need your snorkel rather than shovel tonight, alas.

Anyone notice the 61mm 16 spot value on the 48 hour 12z NAE precipitation around the Taunton environs? Edit: Oops, sorry that's 16 <slaps wrists>

What an interesting satellite pic. Is that showing West Is Best's lawn? The bit underneath the word snow? From coast to coast? Bleeding heck, I wouldn't want to have to mow that lot

Just before Christmas I went for a wander around Spread Eagles Hill, by Compton Abbas. There was a fair bit of ice around then - managed to cut my hand up on some rather nice rusty barbed wire as I found myself sliding down the slope. Ended up walking back up the side of the hill from Compton back towards the airport & car park. I wondered then what it would be like to sled down the side there. Unfortunately I have niether the time or the cajones :lol: Oh and I had about 5 heart attacks walking up the hill. Can't keep doing that. I bet the folks down in Melbury Abbas "love" it when it's snowy and icy down there. As for this current load of rain/sleet and snow, I still haven't seen anything to grab my attention. Sure, lots of folks are going to see snow - it just isn't going to be anywhere near me [er, probably].

Fellow south coast Dorsetians will surely have a wry smile when they see the graphic for the MetO warning. Note that Bournemouth + Poole have been left as yellow !! If I had to stick my neck out, I would say that South of the Doreset Downs will be looking at a slushy mess at best. I just can't see sufficient cold advection to bring snow to low levels here. The deepening and North Western placement of the low should send the colder air further East and North IMO. Still, we won't know for sure for a while yet... That reminds me, I must update my location back to Bournemouth.

Little has really changed synoptically to cause the latest output. The shortwave may develop, it may not. There are too many variables to really know at this stage. We do know that the conditions seem to favour the shortwave to become organised, however. The possible side effect is that the initial precipitation will perhaps become more margnial as air from the channel becomes mixed in, however I'm not overly concerned about that. Anyway, to demonstrate that small changes on the synoptic scale make big changes in precipitation, I've been putting my IMBY glasses on and saving the Tue/Wed Net Weather GFS derived forecast for Bournemouth since the weekend (when the GFS first drived up that shortwave) Tuesday: Wednesday:

I don't think many of us that have been watching over the last couple of days will be surprised at the latest snow threat showing up. Both GFS and NAE are keen to close off the flow around the Western edge of the front. I've been pondering since the weekend what the driving factor for this is. I think it's a combination of things. There is jet forcing from a jet streak to the west - placing the western edge of the front on the difluent left exit - this favours cyclogenesis. Additionally the cold air moving out south over the warm channel water causes enhanced convection - i.e. uplift. In any event, whether this actually happens or not is another thing. It's certainly something the GFS has been keen on in an on-and-off fashion for some time. It could enable significant snowfall. However, massive emphasis is on *could*...

Compare these 2 super-ensemble outputs from here. See the explosion of scatter that just one day makes... 18th 19th

Looking at the UMNO-NAE meso output, it's fair to say that Kent has some potential for tonight. From an IMBY point of view I'm looking at an area of possible disruption around for M4/A34 area. There looks to be a line of precipitation from the wash down towards Salisbury. The first real precipitation moves in tonight and then carries on overnight. Could be interesting... You can see that the flow of upper cold pool aligns with the showers: The ouput has rendered it as rain but I think it's very likely to be of snow: Potential for visibility to drop below 8ks Temps likely to below freezing: Pricipitation accumulation indicates the potential for some disruption. Some impressive totals in the far SE: Lastly, predicted snow depth by the end of tomorrow:

Looking at the UKMO-NAE output, the snow this morning is not totally unexpected. I've had a spare hour to lose before a fun filled day dealing with whinging customers. So, here's my analysis for our region based on the 6z UKMO-NAE. I've focussed on some of the parameters from John Holmes' "Will it snow guide". Looking at thicknesses for 500-100hPa: Sub 528dam covering south east of a line from Lyme Regis to the Wash initially. Higher thicknesses move in as the low sweeps down the North Sea such that by 6pm only Kent really has air with a thickness below 528dam. As the low sweeps South, the colder air moves in from a North East direction, bring sub-528dam air back to all of England and Wales, except for the far South West, by 9am tomorrow. That remains through to the end of the model run at 6am Friday. Only North West Scotland and Central Ireland Westwards remain in air above 528dam. Looking at 2m temperatures: South of a line from Bristol to the Wash, largely below 0 at 6am this morning and widely below freezing until mid-day. Warming up to 3-4c as the low moves South. Staying that way for us until the low clears away and by 6am Friday we're looking at -2 to -3 in our region. 850 temperatures: Starting off at -5 to -6 this morning and rising slightly as the low sweeps south. Staying below zero throughout though. Steadily falling as the colder air works in and by Friday morning we're looking at -10 to -11 at the 850 level. 850-500 thickness: Starting off between 1290 and 1300, with the lower thicknesses South East of a line from Weymouth to Norfolk. These thicknesses increase as the low moves South in the same way as the 500-100 thicknesses above. Sub 1290 thicknesses move back in Thursday and cover most of the region by mid-day. By midnight, the whole region is covered with thicknesses below 1280dam. Precipitation: A small amount falling pretty much anywhere, with larger amounts of preciptation in the North East corner of the region. No significant amounts though, likely to be mainly light to moderate showers. There's a chance of anyone in the region catching a shower throughout, however the more North East you are in the region, the higher the chance. Summary: Staying cold. Becoming colder from Thursday onwards. A chance of a shower anywhere, with more showers likely in the North East of the region. Conditions initially conducive to light sleet and slow showers this morning, especially on higher ground but those mostly turning to drizzle by the afternoon. Probably staying widely above freezing overnight tonight with isolated showers of drizzle in the North East and some mist throughout the region. From mid-day tomorrow onwards, any precipitation will be increasingly turning to snow, and by Friday morning I think snow anywhere rather than rain or sleet, save for a few areas right on the coast. Precipitation totals look small for this period but some areas may get a light accumulation of snow.

I apologise in advance for the ranting nature of this contribution! Due to time and other reasons I've been content to be a very irregular read-only patron of Net Weather for the last couple of years. I must say that this Autumn/Winter it has almost driven me to drink. I don't blame anyone in particular but this, to me, is nothing like the place it was 4-5 years ago. That is neither good nor bad, it's just progress I suppose. Without wanting to be patronising (but no doubt sounding like a pompous git), I feel a lot of the friction in the Model thread is caused by either young or inexperienced members. It's easy to forget that it is not mandatory, nor desirable, to share your every thought with the world. I've noticed that some members who used to irritate me in the past with pointless and childish posts now post with a great deal of eloquence and thought. I'm aware that this is as much a case of me being older and grumpier too. Too many people ask questions that have been answered at length many times before. If you can’t be bothered to search the forum, or type something into Google, why should anybody else bother to help you? I also think some people treat this forum a bit like MSN and expect instant gratification. It just irks me that if some of these people diverted their seemingly boundless energy from what is, brutally, a pursuit that is pointless as far as human advancement is concerned, to a truly worthy pursuit our race would be a lot better off. For instance, why not try to find a better way of approximating the Navier Stokes equations? Not only will it lead to an advancement in numerical weather prediction you can also pocket a million bucks from the Millennium Prize folks too. If you have no idea what the Navier Stokes equations are, you probably don't have any business criticizing a numerical weather prediction model... After getting all that off my chest, I do have a recommendation. Clearly from previous years separate threads die a death quickly. I remember trying to look in vain at various topics such as data assimilation weaknesses but these fall off the bottom very quickly. The same has/will happen with any technical thread. A new style of thread is wholly reliant on its users to make it a success. What I would propose is one of two things: i) A pinned in-depth thread where all contributions are pre-moderated and clear posting standards are set – minimum length, relevancy etc. Then a moderator can allow or disallow a post in that thread based on clearly defined standards that apply to everyone. That way everyone knows where they stand. I suspect that this would see little use, though. ii) Giving a filter option for the main discussion thread where one can click a button and view just the posts by the forecast team that have been made in that thread. More difficult but better would be where each user can create a “want to read posts by” list where they can add the users they want to read posts by in a thread. That way at a click of a button you can have the normal thread or your own customised thinned-down thread. I don’t like the ignore function for this as this is too permanent and rather than say who you don’t want to read posts by, say who you do want to read posts by. I also think it would be better that it’s something you can turn on when needed rather than something that’s always on. Ignoring someone in perpetuity because they may have annoyed you one day isn’t great for the community really. I’ll crawl back from whence I came now

It didn't escape my attention that last week there were many Brixtons felt in Abingdon. This notion made me feel rather uncomfortable. It's like saying that there are several inches in a centimetre. Perhaps consideration could be given to revising the nomenclature? Anyway, here is a new definition for the dictionary: Snow Job: What a gentleman who is snow starved may be tempted to buy. Usually about £25 for a quickie. Consists of trawling the streets of less salubrious areas (such as Portsmouth or Carlisle) for purveyors of this particular act. The act itself consists of being taken to a darkened room which contains illegal snow imported from Russia. The gentleman can then entertain himself however he wants in said snow. Going all the way is about £40 and allows the chap ample time to build a snowman and/or get frost-bite. Gloves are recommended for "Safe Snow" to avoid the possibility of contracting a STD (Snow Transmitted Disease). As an aside, the snow smuggling rings that operate throughout Eastern Europe are thought to be operating under the control of a militant faction headquartered in the Peterborough region.

Great pics Iceberg and thanks for sharing. Interesting that down on the coast in Bournemouth there's been little settling snow. We did have constant snow for periods last week but the accumulations never made it over 1-2cm. I've often noticed a stark difference in weather when crossing the hills - (I suppose they're the Dorset Downs but I've never bothered to check) on the way up to Bath. Usually go on the top road from Blandford to Shaftsbury - through Melbury Abbas. Melbury can be pot luck in good weather, I wouldn't fancy that with the snow and ice around!!! Narrowly avoided getting taken out by a fast retreating burger van there once.