Statistical guidance for the North Sea

Since 1991 a statistical forecast for the oil platform K13 has been available to the forecasters of the Maritime Meteorological Service(MMD) of the Royal Netherlands Meteorological Institute (KNMI). This so-called K13 guidance provides wind and wave forecasts up to five days ahead. It is based on statistical interpretation of model output from the European Centre for Medium-Range Weather Forecasts (ECMWF) as well as from the UK Meteo¬rological Office (UKMO).

The shipping and off-shore industry, commercial clients of the MMD, need detailed forecasts of the wind and the sea state for various locations in the North Sea. Also for safety reasons detailed weather forecasts are indispensable in this area. To meet the requirements of the customer there is a clear need to extend the K13 guidance to other locations.
This paper describes an extension of the K13 guidance which will be referred to as the ’nautical guidance’ in the remainder of the paper. It provides forecasts of wind direction, wind speed and maximum wind speed (at 10 m), significant wave height and significant wave period at four locations in the North Sea. These locations are: AUK, EURO, K13 and W4. Forecasts are made for 12 and 00 UTC for day 1 until 5 (based on +36 until +144 atmospheric model output). An example is shown in Fig. 2. The guidance is issued once a day and is available to the MMD early in the morning. Unlike the K13 guidance the nautical guidance only uses ECMWF model output.

The data used are summarised in section 2. In addition, the reason for not using UKMO products is explained. In section 3 the final predictor selection is discussed. In section 4 verification results for the winter of 95/96 are given. Also, for the shorter forecast ranges a comparison is made with the HIgh Resolution Limited Area Model (HIRLAM) wind speed forecasts as well as with wave height forecasts produced by the Dutch limited area wave model (NEDWAM). Finally, a few concluding remarks and plans for the future are presented in section 5.