The 5 day FGS

Since its inception in 2011 the Scottish Flood Forecasting Service has provided forecasts of flood risk out to five days, by way of the Flood Guidance Statement sent to the emergency response community. Since then the scope and accuracy of medium range forecasting has increased markedly, with the result being that a reasonable view can be taken of at least the possibility of extreme weather occurring beyond the five day forecast window.

To this end, we are now able to provide an outlook for the 6 – 10 day period, on occasions where the forecasts suggest something significant, and when we feel it would provide some meaningful information to the customers. Some example of times when this might be appropriate are:

• High spring tides, which are generally known about long in advance
• Ex-hurricanes with long lead times, that might cause significant impacts, whether through extreme rainfall or large storm surge
• Just prior to extended holiday periods, to aid resource allocation
• Expected thaw following an extended cold spell and long build-up of snow
• During a prolonged significant event to indicate when things are likely to ease up

Hurricane Ophelia – well forecast rain and surge

It’s not expected that this section of the Flood Guidance Statement will be used very often, but the ability to use it will allow us to provide useful information when available.