In a two-part feature, we cover various roles involved in decision making at times of uncertainty. The first is provided by Paul Ryles, Senior Scientist and operational flood forecaster at SEPA.

Paul manages SEPA’s flood risk management and operational hydrometeorology trainee programmes and has been in flood warning service development since 2002

“Flood prediction is a science, especially in challenging situations such as providing long lead times (for example through our five day flood guidance statement) or flash flooding (surface water alerting). One of the primary roles of the flood forecaster in these situations is in communicating uncertainty in a way that is useful for responders. The forecaster must quantify uncertainties in the weather forecast (in terms of location, timing, intensities and amounts of rainfall) and any potential uncertainties in the resultant flood forecasting predictions and hazard footprint.

Meteorological and hydrological tools such as MOGREPS and Grid-to-Grid provide the forecaster with the opportunity to quantify uncertainty in flood predictions. Image of MOGREPS-G and probability of greater than 25mm in 24 hours ahead of ex-Hurricane Kate (Copyright Met Office)

Understanding what type of information customers require is vital, as is an appreciation of how this information will be used and what type of decision will be made. The flood forecast will often be used to make crucial ‘yes or no’ decisions, such as committing resources in responding to a flood event, evacuations or deploying temporary flood prevention measures. Understanding these customer requirements is as vital as knowledge of meteorology and hydrology in producing successful flood forecasts.

Flood Forecasters participating in Exercise Big Water, testing response and preparedness to new coastal flood forecasting capabilities.

Having competent and experienced flood forecasters is essential in delivering this service. To this end, the Flood Forecasting Service, with support from the Met Office College, has developed a formal qualification in Operational Hydrometeorology. The aim is for all of our flood forecasters to achieve this qualification, which assesses all aspects of producing and communicating our flood forecasts. The forecasters, who will already have completed training in flood forecasting, warning and response, will undertake this qualification after a period of on-the-job training.

Forecasting some flood situations remains a challenge, however ensuring all flood forecasters are trained and competent (and assessed) in accounting for, quantifying and communicating risk at times of uncertainty should maximise the benefit of flood predictions for responders when making difficult decisions.”