Decisions, decisions, decisions --- weather in the real world
by Gerald Fleming, Head of Forecasting, Met Éireann
Gerald Fleming took out B.Sc and M.Sc degrees in Experimental Physics in UCD before joining Met Éireann in 1980. He has worked in forecasting for the past 29 years, and is currently Head of the Forecast Office. He is a past Chairman of the International Association of Broadcast Meteorology and was Co-Chair of the First World Conference on Broadcast Meteorology (Barcelona, 2004). A member of the Irish Meteorological Society and the American Meteorological Society, he is also active in the European Meteorological Society where he is Co-Chair of the Media Committee. He also chairs the Public Weather Services Group for the World Meteorological Society. Outside of Meteorology he is a past Chair of Wexford Arts Centre and active also in Wexford Swimming Club.
Most of us use weather information to make decisions on a daily basis. Will I wear gloves today? Bring an umbrella? Put my name down for a time at the golf course next Saturday? Busineses make much bigger decisions when weather is one of the more important inputs. Should a supermarket stock up on ice-cream before the weekend? Does the butcher need to have barbecue meats for sale tomorrow? Should a farmer spray the crop today or later in the week? Should the energy company forward-buy oil for next week?
All of these decisions need weather information, but they need other information too; the costs of taking the decision and the potential losses of not doing so. A rational system of decision making would match up the cost/loss ratios with the likelihood of the specific weather event taking place (or not, as the case might be).
Estimating this likelihood has never ben easy, but now the products of ensemble prediction systems offer a credible tool for putting a numerical value on the confidence of a given weather event. How to apply this tool is a new problem for society.