July 2013 has been the worst WeatherAction forecast since I began my analysis in April 2012. The weather has been dominated by high pressure which has resolutely stuck fast over the British Isles. Piers Corbyn had forecast attacks of low pressure, cool weather, with the jet stream being generally quite south. This has not happened. He released a statement to subscribers acknowledging his forecasting error, but expressed a belief that by the 23rd of the month the general weather pattern would revert to his general forecast pattern, which it did.
Corbyn was sometimes wrong for up to a week at a time throughout the April-October 2012 analysis, but never for longer than that. In July 2013 he was fundamentally wrong for 3 weeks.
Were July 2013 part of my analysis then his forecast accuracy would be reduced to around 65%, or lower. On the 18th he put out a statement admitting that things had not gone well and that he was revising his SLAT method, now known as SLAT9, to accommodate an updated understanding of "cut-off Highs". If this July forecast is an aberration then it ought to be dismissed because such errors would invariably happen in any emerging science.
The Met Office forecast that the Jet Stream would remain northerly for all of July, which turned out to be correct as far as the first 3 weeks, though this forecast could easily have been made by looking at the numerous Jet Stream forecast websites – one of which they make reference to on their website. The Met Office prediction doesn’t exactly smack of “rocket science”. Furthermore, it does cast into doubt the Met Office’s idea that various oceanic and ice cover trends will cause cool and wet weather in the summer which, this year, has not transpired so far. There is no reason to believe that the Met Office have acquired any significant ability in long-range forecasting. And, whilst many criticise Corbyn for not revealing his methods, the Met Office have not done so either regarding their attempts at longer-term forecasting (“statistical analysis” we’re told).
Based on my 2012 analysis and the high level of success of his forecasts in the first half of 2013, I remain a supporter and advocate of Weatheraction. This is not out of blind faith or any prejudice in favour of his radical views on Global Warming; I just believe that if he has something to present then he should not be dismissed outright by the established meteorological society. After all, it would be nice to be able to get 90% accurate weather a year ahead if only Weatheraction and the Met Office could work together.