Why Should I Care?

Since our last post about seasonal prediction of tropical cyclones, one of the organizations (the UK Meteorology Office) mentioned in that post has come out with their official forecast.  The UK Meteorology Office, or simply Met Office, has made a prediction that is substantially different than the other forecasts to date.  Traditionally the Met Office is the last to issue their forecast each season, but often their forecast will be in line (but not always) with the other agencies we discussed last time.  However, this forecast seems to speak to the very question posed previously – Are Seasonal Tropical Cyclone Predictions Useful?

Now, on the surface one it seems logical to conclude that this prediction proves that all these forecast are too speculative and the difference between them means they are not useful.  Looking at the image to the right you can see that the Met Office forecast is significantly lower compared to other May/June forecasts.  If you consider all the forecast as having an equal basis (essentially issued at the same time) it would logically lead one to infer that this season has a great deal of uncertainty based on the variance between the forecasts.  However, you could also speculate that there is some meaningful underlying reason for this difference between the projections.  The image shows the forecasts made in chronological order, so is it possible that the Met Office is seeing things differently with a couple of extra weeks of data?  While the technique used by the Met Office is different than the other forecasters (see an explanation on their site), it is unclear as to how different the forecast might have been if issued a month or just two weeks earlier.  If you are so inclined to buy their full report you might get a bit more insight into that possibility.

Another interesting perspective about this forecast is the similarity with a forecast made by the Weather Research Center.  While not as well known as some of the other forecasters, they have been making predictions for over 20 years.  It would be beneficial if they provided a bit more detail about their technique and its basis on their website, but there is at least enough information there to get the gist of their technique – essentially it is based on solar activity.  We have been in a relatively quiet sun spot period (read a bit more on Dan’s Wild Wild Science Journal) and this has WRC predicting only 7 named storms this year in the Atlantic Basin.  It is interesting that this forecast is so close to that of the Met Office, making one wonder to what level sun activity influences the models used by the Met Office.

So come seasons end who will prevail – the pack with the ‘near normal’ prediction, the ‘quiet season’ forecasters, or neither?