Weather forecasters have always been the butt of jokes...

...particularly in the UK, where foul weather is the national preoccupation...

The UK Met Office famously forecast this past winter to be milder than average...
25 September 2008 ...The Met Office forecast for the coming winter suggests it is, once again, likely to be milder than average.
Seasonal forecasts from the Met Office are used by many agencies across government, private and third sectors to help their long-term planning.

The meteorological winter is over, and the official results are in :

The UK had its coldest winter for 13 years, bucking a recent trend of mild temperatures, the Met Office has said.
The average mean temperature across December, January and February was 3.1C - the lowest since the winter beginning in 1995, which averaged 2.5C...

...from "milder than average" to "the coldest winter in 13 years" is not just a slight blunder for a quasi-scientific body, on whom many individuals, businesses and institutions depend. Forgive the cynicism, but it seems that Met office personnel may just have made a guess, or let their ideology about global warming interfere with their objectivity, or perhaps just closed their eyes when they threw the dart...
Where are all the satirical TV shows of the past when they're needed ?

...and this, from another sceptic, William Happer Professor of Physics, Princeton University in a testimony to the US senate..."...Many of the frightening scenarios about global warming come from large computer calculations, "general circulation models," that try to mimic the behavior of the earth's climate as more CO2 is added to the atmosphere. It is true that climate models use increasingly capable and increasingly expensive computers. But their predictions have not been very good. For example, none of them predicted the lack of warming that we have experienced during the past ten years. All the models assume the water feedback is positive, while satellite observations suggest that the feedback is zero or negative..." more here...