Picture representing surge and tide.
Storm surge modelling
A storm surge is the change in sea level produced by wind and atmospheric pressure
variations. Unlike the tide, this cannot be predicted far in advance as weather conditions
change on a regular basis, and can only be accurately forecast up to 3 days ahead. The predicted
tidal height plus the surge is used to determine if a flooding event is likely.
When atmospheric pressure is low and coastal winds are onshore with high speeds then a positive
surge will occur. This can cause coastal flooding if the surge event coinsides with a high tide.
(Negative surges combined with a low tide can cause other problems e.g. for navigation when ships
Storm surge prediction is important for warning of such events, to help prevent damage to property
and loss of life.