British Weather!

This week, torrential rain and strong winds combined to create severe flooding in a number of regions across the UK.

These floods have mainly been caused by the heavy rain. The most dramatic inundation from the sea, so far, may have been the sea foam pushed on shore near Aberdeen, a result of high winds blowing shoreward from a choppy sea. However, flood forecasters have been keeping a particularly close watch on the elevated levels of tidal rivers, which could be catastrophic when combined with a high tide.

A stormy sea

According to the Environment Agency (EA), coastal flooding is flooding that “results from a combination of high tides and stormy conditions. If low atmospheric pressure coincides with a high tide, a tidal surge may happen, which can cause serious flooding.

Sea level data can help our understanding of coastal flooding in a number of ways. The Met Office runs a computer surge model (PDF), which incorporates modern real-time tide gauge data and will alert the EA if the forecast comes close to a danger level.

Historic tide gauge data is useful for ascertaining the frequency of storm events. These data can be used in planning future flood defence measures. The EA ran the Thames Estuary 2100 project to develop a long-term tidal flood risk management plan for London and the Thames estuary. Historic sea level data from 6 tide gauges along the Thames was quality controlled by BODC and used in the project.