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recklessabandon

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Posts posted by recklessabandon

    What Is The Snowiest Place In The Different Parts Of The Uk?

    in Spring Weather Discussion

    Posted

    To add to those in Durham, Blanchland gets cut off regularly as does Muggleswick - drifting in an Easterly being the most likely cause...

    yeah they are in areas will very little tree or topographic shelter which means a nor'easterly or easterly has a pretty unrestricted run at the roads, compounded by DCC's woeful road management programme (but that's for another discussion!)

    Also to alza - yeah I agree Wooler area is a good reference point and gets hammered, be interesting to see some proper numbers from that area, though under the right conditions (Dec 2009 for example) Consett can be hard to beat once the wind funnels up the Derwent Valley.....

    What Is The Snowiest Place In The Different Parts Of The Uk?

    in Spring Weather Discussion

    Posted · Edited by recklessabandon

    For NE England - in terms of towns Consett for sure, I would have also said Alston but it is Cumbria so I'll give that to the North-west.

    For villages - I'd go for one of the upland Durham villages, maybe like Lanehead, Wearhead etc, though Waskeley might end up being an unlikely winner due to its susceptibility to picking up heavy snow from a nor'easterly wind too.....

    I also think one or two of the Northumbrian villages in the Cheviot area might also get messy.....

    The Winter 2011/12 Forecast Thread

    in Spring Weather Discussion

    Posted

    November:

    1st - 10th - Numerous outputs, trends and patterns point to a North/South split during the first third of the month. It's looking very likely that it's going to be very average in the North, day time temperatures hitting 8-10C, but above average in the South, temperatures hitting 13-16C. Precipitation wise, the first start of the month looks like being very wet and unsettled, perhaps making up for the drought in place in Eastern areas. An Atlantic dominated first third, night time temperatures unlikely to bring any frosts at all away from the coldest of hollows.

    10th - 20th - This period will follow the same theme as the first third for a time at least, with temperatures being pleasant enough in the South for T-shirts to be worn. In the North though, it's again very average for the time of year until the mid month point at least. Temperatures again 8-10C, 13-15C in the South. It's the mid month point that may bring some interest to you with the first frosts of the month likely, temperatures still recovering to average by day. This third is likely to be the windiest with frequent gales, especially in the West.

    20th - 30th - Another dissapointingly average period with little in the way of Winter to be shown just yet. Temperatures again remaining oh so average, although temperatures may be down a little way at least, 5-9C in the North, 10-13C in the South. Rainfall should be around average for the time of year, as should sunshine amounts. A cold spell is likely around the end of the month (The very end of the month) giving the first low level snow to Northern & Eastern areas, this may also mark the start of the Cairngorm skiing season. Frosts are also likely towards the end of the month, but Western and Southern areas are going to have to wait to see anything remotely in the way of snow.

    Wow. I am very surprised at how accurate I have been? I must be learning, as I don't think last year's forecast by me was as accurate as this!

    Fair play to you - especially as your December forecast (at least the first half for now) looks a good bet too....

    An Odd Snow Paradox

    in Historic Weather

    Posted

    I've seen numerous pictures of this, in the Lake District, where snow was on the ground near the lakes but between the peaks and the ground, there was no snow.. I can try find the picture I'm thinking of.

    Here it is

    I think this might all be down to the sun in the case of this picture. This shot shows the south facing slopes of Skiddaw, which a roughly at 30 to 45 degrees, meaning in mid-winter they are pointing directly at the low aspect sun, and thus melting the snow. below this the frost hollows and valley shade maintain the cover, above this, the cold wins out. If you look at the valley to the immediate south west of the summit, it holds snow much further down, and that is a south east facing aspect, thus only getting morning to lunchtime sun, not the more 'radiant' sun from the south and west which is generally more effective and melting.

    Also, this effect can also be seen in more extreme ways in the alps, with alternating layers of cold and warm air under benign conditions.

    Model Bias?

    in Forecast Model Discussion

    Posted

    Model bias – true or untrue.....?

    thanks John, quite interesting. It was I who was raising the question/issue of the difference between statistical bias (especially that of variable omission bias) and cognitive bias. I was certainly not suggesting the any forecast models are influenced by cognitive bias (though reading some of the winter forecasts I do wonder :rofl: ....)

    Anyway, I think part of the confusion came from the definitions, clearly the METO have their interpretation of bias which of course in statistics is perfectly understandable, given how many different 'types' of bias one can encounter.

    One question that does remain to me though; if the models are taking a global view over a known square area, how do they compensate for those regions of the globe where data on the ground may be very sparse, lets say the sahara regions of Africa as an extreme example versus western Europe, is provision given in the models for potential 'gaps' in ground-based data sets ( I am assuming that to a degree in-filling will be given by satellite).

    Corbyn - Winter Warning Of Exceptional Uk Cold And Snow

    in Spring Weather Discussion

    Posted

    The models do not have any bias. They may have characteristics that manifest themselves (which might mistakenly be attributed to bias) but that is an error in the programming, or data collection, not a bias based on trends. It might 'overcook' convection given high CAPE values, for instance - which is a 'mistake' (I say mistake, it's probably not enough resolution more than anything else)

    At the risk of getting caught up in semantics, we need to be clear. I think the argument is that the 'bias' is being referred to in the statistical sense rather than cognitive sense. Bias in the statistical sense is exactly what you have described above. I personally never suggested that there was bias in the cognitive sense in the models, because although they are under human control, they are objective numerical models. I suggested that statistical bias may be occurring because of the skew in available data and the way it is used (as per earlier comments) from different sources, which might suggest a skew, or bias, toward zonal type conditions.

    Corbyn - Winter Warning Of Exceptional Uk Cold And Snow

    in Spring Weather Discussion

    Posted

    hi

    I think you will get a much more comprehensive answer to your question if you google UK Met Office web site, and go to the section on computing. Masses and masses of information in there. I hope that helps.

    There is no bias though for any weather pattern, large or small amounts of data, but its all in the detailed explanation on their web site.

    thanks John i'll have a look. in terms of the question I think we (me for sure) were looking at the effect of missing data causing over-compensation in certain areas, especially when the 'ground' data sources we were relying on were from areas where our weather generally does not prevail 'from' therefore increasing the risk of data 'gaps' (IMO) and 'skewing' - probably a better description than bias, which suggests an inclination to one thing or another (almost by design).

    Corbyn - Winter Warning Of Exceptional Uk Cold And Snow

    in Spring Weather Discussion

    Posted

    sorry there do not have any bias but simply work on the physics of the atmosphere solving the enormously complex equations with equally complex maths but no bias.

    If you do not believe me please e mail UK Met and ask for their view.

    Given the huge amount of data input variables the models have to process, can they not be subject to bias through omission of a particular variable, or are there safeguards in place to stop that? For instance if an input variable is missed because it is not fully understood or through poor data collation, then over-compensation can occur.

    So lets say one area of the ocean has far more data collation points than another area because of the prevailing weather conditions, could there be a risk of overcompensation - because on occasion our weather 'flow' comes from a northerly or north-easterly where there are fewer data collation points leading to over-compensation and potentially therefore variable omission bias?

    Corbyn - Winter Warning Of Exceptional Uk Cold And Snow

    in Spring Weather Discussion

    Posted

    Not sure about the above - models aren't biased in that way, and there were a lot of indicators for cold prior to this point.

    I recall upstream indicators for cold being there from early November for sure....but in response to below....

    But last year the models at this point were not showing any hint of cold either - it was literally an overnight thing when the models suddenly all started showing the cold coming in.

    It was explained by those more technical people who understand how the models work that the models are biased to mild winters as that's what statistically we are more likely to experience.

    If you remember last year when the cold kicked in - FI was always trying to show the quickest route out of the cold and back to mild. This went on for weeks before we did eventually get back to mild - but not the way the models wanted to do it - it wasn't -15'C one day and 15'C the next.

    I also recall quite a long discussion on the 'bias' of the models, though I think it was possibly more related to the way they handled the data, in that there is for more information/data 'experience' (if you know what i mean) for zonal type conditions, and that, the blocking and synoptics that we saw last winter were far less usual and more difficult to handle for the models - therefore out in FI they wanted to revert to zonal type until there was sufficient upstream information to maintain the 'blocked' synoptics in the near-time forecasts.

    I am sure there are others out there who will recall this and can explain it far better than me.

    Winter 2011/12 - General Discussion

    in Spring Weather Discussion

    Posted

    I have my own theory that when Britain is undergoing economic hardship, instability, and social problems, we get our snowiest winters:

    1946/47- after the war

    1978/79- winter of discontent

    1980's- mass unemployment, social inequality

    2008-now- recession, unemployment

    Of course 62/63 was cold but it wasn't really THAT snowy.

    And the less snowy winters;

    Late 50's, 60's, early 70's- relative boom in growth

    1993/1994-2008- increased prosperity and growth

    Of course some winters don't follow the theme, but it sure is an interesting pattern.

    There has been some research into the relationship between economic output and climate, I do know for one James Lovelock has looked at this. I know this is slightly off-topic. Essentially in our carbon based economy boom times = lots of greenhouse gas output and particulate output, during recession this reduces relatively speaking.

    The question is, what is the link, is it that because increased particulate output reflects sunlight, and the lag effect of this simply co-incides with our relatively rythmic boom/bust economy to cause a slightly cooler period during the recession periods or, is it because during boom times we output a relatively higher concentration of 'greenhouse gas' which results in relatively warmer periods?

    As for this winter....lots of talk on some French websites predicting a very snowy season in the Alps - could this suggest that some in France are also predicting a more southerly tracking jet, bringing the conveyor of weather systems to their shores.....?

    North East England Cold Spell Dicussion

    in Spring Weather Discussion

    Posted

    Hi All

    Got a meeting in Chester-Le-Street driving up the A1 from York.

    Does anyone have any forecasts for roads around this area?

    Cheers

    As it was showers its a little hit and miss, we have around 30cm-40cm (Consett) lying so I wouldnt recomend it.

    A1 has had various closures between Catterick and Newcastle so you will need to check with the traffic websites.

    North East England Cold Spell Discussion

    in Spring Weather Discussion

    Posted

    Upland roads in pennine Co durham are now extremely hazardous due to fresh snow and existing snow blowing - pls keep away. We have just had to airlift 6 motorists from the Teesdale area.

    I am Team Leader - Teesdale and Weardale Search and Mountain Rescue Team

    Can I add to this that DCC have closed most of the higher roads and 'passes' including Kilhope, Crawleyside, Langdon Beck to Alston etc etc, be very careful if your going to play in the snow....drifts are now as high as houses in places.

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