Weather Forecasting Tournaments: Performance of different Models and MOS Technologies

Philip Lorenz and Klaus Knuepffer
Meteo Service, Germany
1pm in NCWCP Conference Center

Weather forecasting contests are an efficient tool to prove the skills of forecasters and forecasting algorithms. The results provide real-time comparative verification response immediately after the observations are present. The Berlin Weather Forecasting Contest ( is running for more than 14 years now: Each Friday more than 100 participants make their forecasts for 12 weather elements for Saturday and Sunday for 5 locations in Germany, Austria and Switzerland. The German National Weather Service (Deutscher Wetterdienst) and the most important private weather forecasting companies in the area take part in the contest as well as enthusiastic individuals (from amateurs to professionals) as well as more than 10 different MOS forecasts - from different MOS developers, based on different models.

 Verification of the results allows interesting insights regarding
 - the performance of different numerical models as basis for MOS
 - the performance of MOS of different providers and
 - the positive effect of mixing of two or more Models in a MOS-Mix.
 - the performance of human and machine forecasts.

 MOS-Mix forecasts are typically ahead of the single-model MOS forecasts, and only a few forecasters are able to score better than the best MOS-Mix forecasts which are available to them a few hours before deadline (Friday 15 UTC).

 Participation is free for anyone. It could be interesting to see a NWS-MOS system participating or, if a similar contest would be running in the US, to take part with our MOS forecasts in this.