Letter: Weather reliability

From Pascal Mailier, Weather Forecast Quality Project

I believe some clarification is in order following Michael Brooks’s discussion of the credibility of weather forecasts (27 January, p 32) and the ensuing correction (10 February, p 19).

My comments on reliability referred solely to the Met Office’s statistical prediction of the winter North Atlantic Oscillation. I showed that, when gauged by means of common performance indicators, their forecasts do not demonstrate more accuracy or skill in the long run than a simple moving average of the NAO indices of the last two winters.

These remarks do not negate the usefulness of the Met Office’s winter NAO forecasts in a wider context.

I have also pointed out that their statistical prediction model has the merit of highlighting key mechanisms, whereas the two-winter moving average merely takes advantage of the properties of the time series of past NAO records without providing any insight into physical causalities.

Reading, Berkshire, UK