Seasonal predictions of heat waves and their health-related impacts

Posted on: 
Thursday, February 18, 2016

Heat waves have been responsible for more fatalities in Europe over the past  decades than any other extreme weather event. However, temperature-related  illnesses and deaths are largely preventable. Reliable sub-seasonal-to-seasonal  (S2S) climate forecasts of extreme temperatures could allow for better short-to- medium-term resource management within heat-health action plans, to protect  vulnerable populations and ensure access to preventive measures well in advance.

In this study:  we assess the extent to which S2S climate forecasts could be  incorporated into heat-health action plans, to support timely public health decision- making ahead of imminent heat wave events in Europe. Forecasts of apparent  temperature at different lead times (e.g., 1 day, 4 days, 8 days, up to 3 months) were  used in a mortality model to produce probabilistic mortality forecasts up to several  months ahead of the 2003 heat wave event in Europe. Results were compared to  mortality predictions, inferred using observed apparent temperature data in the mortality model. 

In general, we found a decreasing transition in skill between excellent predictions  when using observed temperature, to predictions with no skill when using forecast  temperature with lead times greater than one week. However, even at lead-times up  to three months, there were some regions in Spain and the United Kingdom where  excess mortality was detected with some certainty. This suggests that in some areas  of Europe, there is potential for S2S climate forecasts to be incorporated in localised  heat–health action plans. In general, these results show that the performance of this climate service framework is not limited by the mortality model itself, but rather by the predictability of the climate variables, at S2S time scales, over Europe.