By Paul Homewood
Following release of provisional rainfall data for the UK, showing that 2012 has been one of the wettest on record, Professor Julia Slingo, chief scientist at the Met Office, tells us
“The trend towards more extreme rainfall events is one we are seeing around the world, in countries such as India and China, and now potentially here in the UK”, adding that “the long-term trend towards wetter weather is likely to continue as global air temperatures rise. “
Leaving aside the fact that the Met Office have also been warning us about droughts lately, let’s take a look at some of the forecasts they were making during 2012.
Each month they issue a 3-month outlook. Unfortunately the ones issued prior to September have disappeared from their archives, but I had already saved the April-June, and also the Sep-Nov forecasts. Along with the Oct-Dec ones, what were the Met forecasting as the year progressed?
On 23rd March, they predicted “The forecast for average UK rainfall slightly favours drier than average conditions for April/May/June as a whole, and also slightly favours April being the driest of the 3 months.”
RESULT – RAINFALL TOTALS WERE 176%, 94% AND 203% OF NORMAL IN APRIL, MAY AND JUNE RESPECTIVELY.
On 24th August, their forecast for September “weakly favours below normal values”.
RESULT – RAINFALL WAS 117% OF NORMAL IN SEPTEMBER.
On 21st September, they said “For UK-averaged rainfall the predicted probabilities favour below normal rainfall during October. For the period October-November-December as a whole the range of forecasts also favours lower than average rainfall”
RESULT – RAINFALL WAS 101% OF NORMAL IN OCTOBER.
On 24th October, they forecast “Predictions for UK-mean precipitation for both November and the November-December-January period are similar to climatology”
RESULT – RAINFALL WAS 111% OF NORMAL IN NOVEMBER.
And on 20th November, “Predictions for UK-mean precipitation for December show a slight shift towards below-normal values – consistent with negative North Atlantic Oscillation conditions”
RESULT – RAINFALL WAS 150% OF NORMAL IN DECEMBER.
So for the seven months between April and December, that forecasts are available for, the Met Office forecast drier than normal conditions in six, and normal in the seventh. They failed to get any month correct, and for the seven months in question, rainfall averaged 36% above normal levels, (which are based on 1981-2010.)
It is very kind of Julia to tell us now that she knew all along it was likely to be wetter. It is just a pity, though, that she forgot to tell us at the time.