Another few centimetres of the white poo has fallen in beautiful downtown Monifieth. Fortunately I was able to keep the driveway clear using only a broom, but it will no doubt mean yet more disruption on the roads, late or missing buses, difficulty walking anywhere due to this country's lack of social responsibility in keeping pavements clear of snow, etc etc.
We've had snow on the ground for around 3 weeks now, which is highly unusual for these parts (although we had snow for that long last year as well). I know it's against the government's directive to link the increasing harshness of British winters with (the absence of) global warming, but after enough colder temperatures, there's no other conclusion that can be drawn. With December about 2/3 over, and no drastic rise in temperatures forecast for the next week or so, it is looking like the month will break the lowest average monthly temperature record by a large margin.
The average temperature for 2010 as a whole is 1.2 degrees below normal for this station, which is a *huge* variation, considering that up to now, all variations have been only small fractions of a degree. Eleven out of the twelve months in 2010 were below normal, some of them significantly so. If that's global warming, I'd hate to see what happens when the climate actually does get colder.
Sunday, 19 December 2010
Thursday, 9 December 2010
Easy weather forecasting
I remember reading somewhere that if you predicted the weather by saying simply that tomorrow's weather will be the same as today's, you'd be right about half the time. Since I now have a fair archive of detailed weather data for my own back yard (dating back to June 2003), I thought I'd give this notion a bit of a test.
Obviously, the accuracy of this method of forecasting depends on how you define "same". If you require all weather readings to be identical over both days, you will never get a match, so we need to define a tolerance. For starters, I have used the maximum, minimum and mean temperatures and the rainfall as indicators, and I've allowed tolerances to be set on each of these values so we can vary the definition of "same".
I've written a little C# program which reads in the data from my station and allows the user to define tolerances for the four key quantities in terms of how much the next day's data is allowed to vary from the current day in order for the two days to be judged as having the "same" weather. The results are rather interesting, so here's a taster.
The data cover a total of 2540 days, between 26 June 2003 and 10 June 2010. If we use the mean temperature as the only indicator, and allow a tolerance of plus/minus one degree C, the prediction is correct 44% of the time (that is, for nearly half the pairs of days, the mean temperature varied by less than 2 degrees C). If we use rainfall as the only indicator, and allow a tolerance of plus/minus 0.1 mm (which isn't very much - it's the smallest amount my weather station can measure), we get a correct prediction 36% of the time.
Requiring both mean temperature and rainfall (with the same tolerances) to match, the hit rate drops to 15%.
If we require all four indicators to match (with tolerances of plus/minus 1 degree for the three temperature readings, and plus/minus 0.1 mm for the rainfall), the rate drops to 4.4%.
I figure the results are interesting enough to merit expanding the program a bit. I could extend the prediction period (e.g. how good is a prediction of the weather n days in advance, rather than just one), produce some plots of accuracy versus tolerance or time lag, and perhaps even try some time series analysis to produce some curves that fit the data and allow more accurate predictions.
However, it does put the forecasts from the Met Office in perspective. If a simple little program that you could run on your mobile phone (well, you could if I wrote it for a mobile - this one runs on a desktop, but never mind) can get things like mean temperature and rainfall correct between a third and half the time just by looking one day ahead, is the met office's multi-million pound computer really giving us our money's worth?
It's a bit like playing the stock market based entirely on past performance of shares, rather than doing some research on the companies in which you want to invest.
Obviously, the accuracy of this method of forecasting depends on how you define "same". If you require all weather readings to be identical over both days, you will never get a match, so we need to define a tolerance. For starters, I have used the maximum, minimum and mean temperatures and the rainfall as indicators, and I've allowed tolerances to be set on each of these values so we can vary the definition of "same".
I've written a little C# program which reads in the data from my station and allows the user to define tolerances for the four key quantities in terms of how much the next day's data is allowed to vary from the current day in order for the two days to be judged as having the "same" weather. The results are rather interesting, so here's a taster.
The data cover a total of 2540 days, between 26 June 2003 and 10 June 2010. If we use the mean temperature as the only indicator, and allow a tolerance of plus/minus one degree C, the prediction is correct 44% of the time (that is, for nearly half the pairs of days, the mean temperature varied by less than 2 degrees C). If we use rainfall as the only indicator, and allow a tolerance of plus/minus 0.1 mm (which isn't very much - it's the smallest amount my weather station can measure), we get a correct prediction 36% of the time.
Requiring both mean temperature and rainfall (with the same tolerances) to match, the hit rate drops to 15%.
If we require all four indicators to match (with tolerances of plus/minus 1 degree for the three temperature readings, and plus/minus 0.1 mm for the rainfall), the rate drops to 4.4%.
I figure the results are interesting enough to merit expanding the program a bit. I could extend the prediction period (e.g. how good is a prediction of the weather n days in advance, rather than just one), produce some plots of accuracy versus tolerance or time lag, and perhaps even try some time series analysis to produce some curves that fit the data and allow more accurate predictions.
However, it does put the forecasts from the Met Office in perspective. If a simple little program that you could run on your mobile phone (well, you could if I wrote it for a mobile - this one runs on a desktop, but never mind) can get things like mean temperature and rainfall correct between a third and half the time just by looking one day ahead, is the met office's multi-million pound computer really giving us our money's worth?
It's a bit like playing the stock market based entirely on past performance of shares, rather than doing some research on the companies in which you want to invest.
Tuesday, 7 December 2010
Still cold
With the first week of December gone, the temperature is still solidly below zero. Last night saw a minimum temperature of -6.3 C which, although not as cold as the -9.4 C recorded last week, is still unusually cold for the location. Fortunately, the temperature is predicted to rise above freezing in a couple of days, so hopefully we can get rid of some of the piles of snow and ice that still litter the streets.
Friday, 3 December 2010
New coldest temperature record
Today saw a new coldest temperature record for the Monifieth station, with the temperature falling to -9.4 C overnight. This is probably not the coldest temperature ever for this location, since I can remember one year prior to the installation of my weather station when the temperature dropped to (at a guess) below -10 C. However, it must be very close to an all-time record.
The forecast for the next few days is for the freezing conditions to persist, although it's not supposed to get quite as cold as this. Watch this space for further developments.
The forecast for the next few days is for the freezing conditions to persist, although it's not supposed to get quite as cold as this. Watch this space for further developments.
Thursday, 2 December 2010
Still snowing
We've had significant snowfall every day since last Saturday, so the stuff is really piling up now. For followers of my weather station data, no precipitation has been recorded since early on Tuesday because the temperature has been below freezing since then, so the snow that falls into the rain gauge doesn't melt and register as precipitation. When the thaw comes (and it can't come soon enough for me) there will be a large blip in the precipitation as a result of the accumulated snow.
It's difficult to say how much snow in total has fallen since Saturday since Sunday and Monday were largely above freezing so a lot of it has melted. It is a very long time since Monifieth has had this much snow however, and as far as I know it has never come this early in the year (it's not even officially winter until 21 December, after all). Hopefully it is just getting it out of its system early, and the rest of the winter will be largely snow-free, but only time will tell (as the Met Office is certainly incapable of telling us).
The one promising bit in the forecast is that the wind direction is due to change to the west over the next couple of days, which means that the east coast should be in the shadow of any snow, so we might get some snow free days. However, the temperature is also set to drop a bit so it's unlikely much of it will melt.
It's difficult to say how much snow in total has fallen since Saturday since Sunday and Monday were largely above freezing so a lot of it has melted. It is a very long time since Monifieth has had this much snow however, and as far as I know it has never come this early in the year (it's not even officially winter until 21 December, after all). Hopefully it is just getting it out of its system early, and the rest of the winter will be largely snow-free, but only time will tell (as the Met Office is certainly incapable of telling us).
The one promising bit in the forecast is that the wind direction is due to change to the west over the next couple of days, which means that the east coast should be in the shadow of any snow, so we might get some snow free days. However, the temperature is also set to drop a bit so it's unlikely much of it will melt.
Wednesday, 1 December 2010
Good old Met Office blunders along...
In case anyone missed this little gem, the Met Office predicted at the end of October that the coming winter would be milder than usual with "60%-80% confidence". (Notice that now they are uncertain about how confident they are, which makes no sense statistically...you predict something with a specific confidence level, usually...).
However, many lowest temperature records for November were broken in the past week, and today's long-range forecast for the last half of December reads: "Temperatures are likely to continue below average, with widespread frosts, sometimes severe."
And these are (some of) the people that we are supposed to trust for long-range climate predictions? Yeah, right. If they argue that "weather isn't climate", I would point out that the same atmospheric models ('general circulation models', since you ask) are used for both weather and climate prediction, and that the models used for weather (i.e. short-range, up to a few weeks) prediction are supposedly more accurate than those used for climate.
However, many lowest temperature records for November were broken in the past week, and today's long-range forecast for the last half of December reads: "Temperatures are likely to continue below average, with widespread frosts, sometimes severe."
And these are (some of) the people that we are supposed to trust for long-range climate predictions? Yeah, right. If they argue that "weather isn't climate", I would point out that the same atmospheric models ('general circulation models', since you ask) are used for both weather and climate prediction, and that the models used for weather (i.e. short-range, up to a few weeks) prediction are supposedly more accurate than those used for climate.
Coldest November on record
The November 2010 records from my weather station are now online (see the Archives link). It was the coldest November on record by quite a long way, with a mean temperature for the month of 4.9 C. Since December is expected to be colder than normal as well, 2010 as a whole is set to be much colder that average.
It's been a while since I've posted anything much on the global warming scam, so I'll take this opportunity to provide a bit of an update on my thoughts. Two things are fairly obvious at this point: first, any international accord agreeing to do anything much about the climate isn't going to happen and second, the number of people who are global warming believers is declining rapidly. The "science", such as it is, hasn't changed. It still consists of the same computer models that aren't capable of predicting anything (or at least, anything that actually comes true), and of course reliable data on the climate still doesn't extend any further back than the satellite era (about 30 years) so the time scale on which current trends are based is worse than meaningless on a climatological basis.
Public belief in global warming was justifiably shaken by the Climategate scandal in which it was revealed the those in charge of pumping out the scary predictions were preventing the skeptics from getting papers published, trying to find ways round the Freedom of Information act to avoid releasing their data, and massaging the data so that it supports their warmist propaganda. Public confidence fell further when it was revealed that the IPCC (the UN's panel on climate change) had cited non-peer-reviewed sources (frequently leaflets produced by greenist pressure groups) to arrive at false conclusions concerning things such as the melting of Himalayan glaciers and disappearance of tropical rain forests.
My own interest in the area is fading, since it is increasingly obvious that the warmists have lost the argument, and that most people are now simply bored with the whole thing. The conference this week in Cancun, Mexico, billed as the successor to the big Copenhagen flop last year, is attracting hardly any media attention and is virtually guaranteed not to produce anything significant. After the mid-term elections in the US, it is highly unlikely that the Americans will do anything much to satisfy the warmists, and surely it is just a matter of time until the other governments in the western world bow to public opinion and life gets back to normal.
It's been a while since I've posted anything much on the global warming scam, so I'll take this opportunity to provide a bit of an update on my thoughts. Two things are fairly obvious at this point: first, any international accord agreeing to do anything much about the climate isn't going to happen and second, the number of people who are global warming believers is declining rapidly. The "science", such as it is, hasn't changed. It still consists of the same computer models that aren't capable of predicting anything (or at least, anything that actually comes true), and of course reliable data on the climate still doesn't extend any further back than the satellite era (about 30 years) so the time scale on which current trends are based is worse than meaningless on a climatological basis.
Public belief in global warming was justifiably shaken by the Climategate scandal in which it was revealed the those in charge of pumping out the scary predictions were preventing the skeptics from getting papers published, trying to find ways round the Freedom of Information act to avoid releasing their data, and massaging the data so that it supports their warmist propaganda. Public confidence fell further when it was revealed that the IPCC (the UN's panel on climate change) had cited non-peer-reviewed sources (frequently leaflets produced by greenist pressure groups) to arrive at false conclusions concerning things such as the melting of Himalayan glaciers and disappearance of tropical rain forests.
My own interest in the area is fading, since it is increasingly obvious that the warmists have lost the argument, and that most people are now simply bored with the whole thing. The conference this week in Cancun, Mexico, billed as the successor to the big Copenhagen flop last year, is attracting hardly any media attention and is virtually guaranteed not to produce anything significant. After the mid-term elections in the US, it is highly unlikely that the Americans will do anything much to satisfy the warmists, and surely it is just a matter of time until the other governments in the western world bow to public opinion and life gets back to normal.
Subscribe to:
Posts (Atom)
