Numerical modelling

Storm surge forecasts

Latest surge forecasts for the next 48 hours from the POL storm surge model run at the Met Office. Forecasts are given for 35 coastal sites around the UK coastline.

  [View latest forecasts online]

Archived forecasts

Surge model monthly verification plots archive. Plots are available from October 2004 to October 2007 inclusive, PDF and PNG (image) formats available.

[View monthly archived forecasts online]  

These plots are also available in a yearly archive in PDF format ZIP archives:
[2004]   [2005]   [2006]   [2007]  

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Maintenance and development of operational tide-surge models

POL develops and maintains tide-surge models used to forecast storm surges on the coasts of England and Wales for the Environment Agency. The models are run in real-time as part of the forecast suite of models at the Met Office. Results are transmitted to the Environment Agency and used, together with data from the National Tide Gauge Network, for coastal flood warning in England and Wales.

First operational surge forecasts were run in 1978 using coarse grid surge and atmospheric models. The present system comprises a 12km shelf model (CS3), with refinements to 1km and a 1-D river model to provide useful predictions in the complex regime of the Bristol Channel & Severn Estuary.

The models are forced by met data from the Met Office's 12km grid "mesoscale" weather forecast model.

Surge models run four times per day producing forecasts up to 2 days ahead. The model surge is combined with tides predicted at tide gauge sites to give the best estimate of the total water level. The Bristol Channel models have also been tuned to provide accurate water level forecasts, eliminating some problems in combining tide and surge in this highly non-linear area.

Model performance is routinely monitored at POL by comparing forecast results with observations every month. Typical RMS errors are about 10cm. Significant forecast errors are investigated and causes diagnosed so that the system can be progressively improved.

Future developments under review include:-

• A high-resolution (3.5 km) model of the Celtic Sea, Irish Sea, North Sea and English Channel
• Improved bathymetry and surge boundary conditions
• Data assimilation from strategic tide gauges
• Very high-resolution (1.2 km) local models in key areas
• Ensemble runs to reduce uncertainty