Validation of the North Sea Storm Surge Atlas by hindcasting historical storms

Jurgen Klein, Mathijs van Ledden, Henk van den Brink, Niels-Jasper van den Berg, Pieter Roos, Suzanne Hulscher

Friday 3 july 2015

12:30 - 12:45h at Oceania Foyer (level 0)

Themes: (T) Flood risk management and adaptation, (ST) Early warning systems

Parallel session: 15L. Flood risk - Flooding

Current storm surge forecasting is often carried out with detailed computer modelling. These models are accurate, but also computer intensive with long calculation times. Also, the forecast horizon is short and the possibilities for scenario assessment are limited. Recently, a Storm Surge Atlas for the North Sea was developed. The Storm Surge Atlas for the North Sea uses a new and innovative method to predict storm surges in the North Sea area and it provides quick insight of storm for five to ten days ahead. The Storm Surge Atlas matches the pressure fields from an ensemble of twenty weather forecasts to a large pre-calculated database. The pre-calculated storm surge found in the database is used for the current storm surge forecast for the entire ensemble of weather forecasts. This research focuses on the validation of the Storm Surge Atlas by hindcasting sixteen historical storms. The simulated water levels are compared to observed water levels at different locations along the North Sea coast. A comparison is made for the peak water levels and duration of the storm surge. Preliminary results show that the Storm Surge Atlas is able to reproduce the peak water levels from the historical storms. Especially large scale weather systems which cover a large area of the North Sea are reproduced well. Smaller scale weather systems or effects due to local geometry are not always captured by the Storm Surge Atlas.