Safe traffic on Norwegian waters
The coastal waters off Norway may potentially be dangerous. Detailed and accurate forecasts of the wave field provide information that may simplify planning as well as being life saving for less experienced sailors. After the tragic Sleipner accident it was declared by authorities on national level that similar accidents should never again occur in Norwegian waters. Polytec was given the task to develop a wave forecast for selected passages. These are available online here.
This was the first step toward making the coastal waters off Norway free of accidents. We are now about to continue the task by upgrading and expanding the forecast. In addition to conventional wave forecasts, future prognosis will also consider different types of special wave phenomenon that can cause especially severe damage.
Conventional wave forecast – how does it work?
The forecast for ocean surface waves is based on methods similar to an atmospheric (weather) forecast, as we use a numerical wave model to predict the wave field at a limited numbers of grid points within a given region. Where the atmospheric forecast model is forced by the large scale weather system, the wave model requires information about the offshore waves, which, similar to the weather forecast, is obtained from a large scale (global) model. Based on offshore wave characteristics such as significant wave height, wave period and propagation direction, as well as the topographic features of the region, the model will calculate the wave field at all grid points using prognostic wave equations.
Present day wave forecast
Today wave characteristics at selected regions along the Norwegian coastline are predicted using a state of the art numerical wave model. Polytec has developed a forecasting system for seven regions in southern Norway: Boknafjord, Sletta, Stad, Breisundet, Hustavika south and Hustavika north. Special emphasis is put on the crossings applied by ferries and commercial fast boats, and therefore the forecasts provide detailed information of the wave height along these tracks. Presently Polytec is working with wave forecasts for two new locations in northern Norway.