Luke Best

Ah - apologies - I still have the old Met Office radar bookmarked. I see the new one is indeed updated every 15 minutes and is not an hour behind. That being the case, I have no idea!!

Hi Katie Met Office radar is an hour behind. You can use the free netweather radar (http://www.netweather.tv/index.cgi?action=radar;sess=) for a more up-do-date picture of what is happening. Cheers, Luke

Haha - I looked out of the window at 5am to do some lamp post watching - only to find that the council have turned the lights off to save money... When the lights finally came on I saw the heavy snow settling and dozed off. Next thing, I'm dreaming that it had all turned to rain and melted, and that I went out on my toddler's trike in search of snow and triked all the way from Christchurch to Poole. So relieved when I woke up!!!

Crofton Close - hoping the roads will be good enough to get me and the sledge (and the children......) to Queen's Park golf course in the morning!

I live just back from the Fairmile pub! I think this one's nailed on Divadee - can't wait for tomorrow morning!

WBFL = Wet Bulb Freezing Level Extract taken from http://weatherfaqs.org.uk/node/64: Wet Bulb Freezing Level Because evaporative cooling is so important in rain versus snow forecasting (see the main FAQ entries, here and here), the wet-bulb 0degC level is a better guide to snow-risk level than the actual ZDL. The wet-bulb is the lowest temperature to which air can be cooled by evaporating water into a sample, which is a mechanism often important in determining whether it will rain or snow at or near the surface. However, note carefully that advection, both cold and warm must be taken into account - the former is particularly important in marginal situations in the vicinity of a well-marked cold front.

Hmmmm..... What's that 960mb dartboard low all about at T162??? One for the shredder methinks. Oops - forgot to quote the original post: Posted Today, 04:46 Xyplode, on 12 January 2013 - 04:40 , said: Post some charts please! im eager to see http://www.wetterzen...s/Rtavn1087.png --> T108 http://www.wetterzen...s/Rtavn1327.png --> T132 http://www.wetterzen...s/Rtavn1627.png --> T162 Edited by Chris D, Today, 04:46.

Slightly off-topic (sorry mods) but I read the following piece (written in 2003) on the TWO website and I think it serves as a timely reminder that we can trawl through model output all day long 'hunting for cold' but every now and again cold will simply arrive 'out of nowhere' (and this is true even now with powerful supercomputers churning through all of the available data). Record Cold Spell of 1987: How It All Started It is well accepted that the most severe spell of weather in southern England since the 'Little Ice Age' occurred in the unlikely year of 1987 in an otherwise 'average' winter. So what brought about such a severe spell and why did it end as quickly as it started. The story begins in the first few days of January 1987, looking at the surface chart a cold spell seemed miles away as a strong High of 1032mb sat over Spain with the U.K. and Western Europe in a strong Westerly flow, temperatures through most of Europe were above normal, however in Scandinavia and Northwest Russia it was intensely cold. The first change occurred quickly on the 2nd as the Iberian High shifted Westwards and low pressure transferred into the North Sea, a brief Northerly swept south across the U.K. but it was hardly cold. By Sunday 4th High pressure was back over France with the U.K. in another mild flow, however by now the models thought something was up and on the Countryfile forecast on the 4th the forecast was for a short but very cold Northeasterly outbreak mid week as low pressure crossed Holland. The models however predicted that the Arctic outbreak would be short and that milder westerly winds would take over again by the weekend. The short cold spell was in fact a non-event as rising pressure over Ireland killed off the Arctic Airflow and by the 7th High pressure was centered over the Irish Sea and the weather cool and quiet. By the 7th the models still couldn’t decide which way things were going to go and the Met. Office remained silent about prospects for the weekend. Things then moved very quickly, a deepening low moved south across Norway on the 8th and into Germanyby the 9th and behind this low there was a massive rise in pressure over Scandinavia. At the same time a large pool of intensely cold air had swept out of Western Russia and was crossing Poland and East Germany, at last the models could see what was going to happen and early on the 9th the message went out: 'Very Cold later in the weekend'. Meanwhile pressure continued to rise over Scandy reaching 1040mb over Finland by the 10th. Sub freezing air reached Eastern England on the afternoon of the 10th and this very cold air reached all areas by dawn on the 11th. The Countryfile Forecast on the 11th was a 'classic' John Kettley saying "The only bright thing on this forecast is my tie!" He rightly predicted freezing temperatures and blizzards all week although even now the depth of the cold was being under estimated. During the day temperatures kept on falling as snow showers became more intense, Monday 12th was probably one of the most remarkable days of the 20th Century as temperatures stayed below -5c throughout England and below -8c in several places in the home Counties. The Weather Log for Jan. 1987 describes the 12th-14th as the coldest spell of weather in southern Englandsince January 1740. Over the next few days the U.K. was swept by blizzards and freezing temperatures as an upper cold pool crossed England. The models showed no sign of a break in the weather and on the Countryfile Forecast on January 18th the forecast was for a very cold but drier week, however within 24 hours this forecast went wrong. During the 19th a warm front crossed the U.K. cutting off the continental feed and high pressure then formed in the warm sector. By the 20th temperatures of 4c-6c were recorded over most parts and a steady thaw began. The next 10 days were dull and sunless the severe spell becoming a distant memory. The interesting thing about the cold spell is the poor performance of the forecast models even up to +72 hours, O.K. computers are better now but I still think they would struggle with a similar chain of events. In a 'New Scientist' Article of July 1987, a group of climatologist speculated that the Jan 1987 cold spell was partly due to GW and we could expect more frequent severe spells in the future! That seems an awfully long time ago. © Andy Woodcock, Jan 2003 So let's not get too down at the sight of a few blowtorch charts in FI, you never know what might be just round the corner. And finally, some eye candy from the height of the January 1987 episode: From this: To this:

I remember a couple of years ago there was cross-model agreement for zonal when quite suddenly a bitterly cold North-Easterly set in and blew for at least a week bringing copious snow showers with it. I've tried to dig out the charts but cannot find the event - if anyone can post these it would make really interesting viewing, especially with the current scenario in mind.

I was in the New Forest and can confirm explosive mid-level growth of AltCas out of a bank of 'moisture'. (looked like the birth of a star in nebula)

Many thanks for the detailed response OMM. Snowing hard now, albeit very small flakes.

Hi OMM - what affects do you expect the wind shifts to have?

I think (certainly hope) that we should do divadee - fingers crossed!

Yes, the temperature rose to 6.6C in the early hours before falling back. Still above freezing though.

Light rain just started in Bournemouth.

I'd stay put. I think the stuff further East is worth chasing this evening, but you say you have to work. IMO best stay on the coast in Bournemouth to see if we get anything early doors off of the Channel. Best of luck!

I feel for you. I was on the clifftop at Highcliffe and saw nothing, although the atmosphere felt electric. Drove home and saw lightning twice as I was unloadingthe car. How lucky is that!

About 30 miles east.

Hi - I'm in X'Church and we had 2 flashes about 15 minutes ago approx. 4 miles to the NW.

Please could someone explain what the Control Run is - it's clearly a run in its own right and not a mean of the ensembles. Cheers Luke

Hi TEITS Another basic question... I understand the Operational and 20 members, but can you explain what the Control run is and how it's worked out for me? Also, has the parallel run now taken over from the old GFS model? Cheers Luke

Hi PubliusEnigma - thanks so much for your response. Luke

Hi I understand that the 'front' denoted in the attached map may actually be a dry line rather than a front. Given that the temperature of the air masses on either side of a dry line is usually fairly similar (and it is the undercutting of the moister air which causes convection), can anybody let me know what effect the dry line might have on my area (Bournemouth) in this set-up. I'd be interested in understanding more about this as the comments I've heard thus far have suggested a warm front that will bring slightly milder air bringing precipitation of a more transient nature to the extreme South Coast. Thanks in advance for your thoughts on this. Luke.

Big storm just passed through Bournemouth over the last hour. Preceded by torrential rain - lots of forked cc strikes and constant thunder. Some very bright lightning from multiple cells. Now moving away East along South coast. Enjoy!!