Global Warming causes lousy weather forecasts

Well, in the UK, by Her Majesty's Meteorologic Office:

In September 2008, the Met Office forecast a trend of mild winters: the following winter turned out to be the coldest for a decade. Then its notorious promise of a ‘barbecue summer’ was followed by unrelenting rain. Last year, it forecast a ‘drier than average’ spring — before another historic deluge that was accompanied by the coldest temperatures for 50 years. Never has the Met Office had more scientists and computing power at its disposal — yet never has it seemed so baffled by the British weather. But there is no paradox. It is precisely the power of this technology in harnessing climate scientists’ assumptions about global warming that has scuppered the Met Office’s predictions — and made it a propagandist for global warming alarmism.

You don't need a weatherman to know which way the wind blows.