By Doug Schneider
Forecasting for Europe can be challenging, as I have little experience forecasting the weather in that region, other than hearing that "it always rains at Le Mans". The forecasting tools that are available to us are more limited as well. Most of the usual tools that I use for North American forecasts don't cover Europe, and I have to search to find new tools. Given these limitations, the Le Mans forecast worked out really well.
The observation point for this verification is the Le Mans-Arnage Airport, which is literally right across the road from the start-finish line and behind the main grandstand. Here's a link to the source of weather data from the airport.
Forecasting for Europe can be challenging, as I have little experience forecasting the weather in that region, other than hearing that "it always rains at Le Mans". The forecasting tools that are available to us are more limited as well. Most of the usual tools that I use for North American forecasts don't cover Europe, and I have to search to find new tools. Given these limitations, the Le Mans forecast worked out really well.
The observation point for this verification is the Le Mans-Arnage Airport, which is literally right across the road from the start-finish line and behind the main grandstand. Here's a link to the source of weather data from the airport.
The weather through the entire event was affected by an upper level low pressure system located off the west coast of France and northern Spain. From the first forecast on June 7, it was clear from this weather pattern that it was going to be a pretty wet event. Rain fell every day except Saturday. With my Tuesday (6/9) forecast update, I mentioned that there would be two main periods of enhanced rain chances - Thursday afternoon through Friday morning, and Saturday night through Sunday.That proved to be pretty accurate.
Thursday could have been a much wetter day at Le Mans, as there were numerous heavy showers and thunderstorms all around the circuit for the afternoon and evening. Luckily for the teams and fans, most of the activity avoided a direct hit on the circuit, and only light rain was reported. Quite a bit of sunshine was able to break through Thursday morning, warming temperatures in the 80s, which I missed with my initial forecast but caught with my Tuesday update. Heavy rain fell early Friday morning before sunrise, with another period of light rain in the early afternoon. I mentioned in my Tuesday update that between a half and one inch of rain was expected through Friday, and 0.71 was recorded at the airport.
Saturday was by far the best weather day of the event. I was uncertain about Saturday in my initial forecast, but by the Tuesday update, I was confident that it would be dry. After a sunny morning and early afternoon, clouds began to increase in the late afternoon and evening. There was a lot of rain over central France that was moving north all day, but from my analysis, I could tell that it would dissipate before reaching Le Mans. I saw several forecasts posted on Twitter calling for rain late Saturday and Saturday night, which never panned out. I think many of these forecasts were taken from automated weather apps that simply regurgitate model output with no human input. I'll have a post soon on why you should be careful with relying on certain apps for your weather information.
Light sprinkles arrived Sunday morning, reported to me by fans at the track through Twitter. But it wasn't enough to measure at the airport until the final hour of the race. My Thursday and Saturday forecast updates highlighted the later stages of the race for rain and mentioned that it would be sprinkles or light rain, which was accurate.
Forecasting for Le Mans was a fun challenge for me. I look forward to doing it again next year. Thanks to all who used and shared our forecasts.
Thursday could have been a much wetter day at Le Mans, as there were numerous heavy showers and thunderstorms all around the circuit for the afternoon and evening. Luckily for the teams and fans, most of the activity avoided a direct hit on the circuit, and only light rain was reported. Quite a bit of sunshine was able to break through Thursday morning, warming temperatures in the 80s, which I missed with my initial forecast but caught with my Tuesday update. Heavy rain fell early Friday morning before sunrise, with another period of light rain in the early afternoon. I mentioned in my Tuesday update that between a half and one inch of rain was expected through Friday, and 0.71 was recorded at the airport.
Saturday was by far the best weather day of the event. I was uncertain about Saturday in my initial forecast, but by the Tuesday update, I was confident that it would be dry. After a sunny morning and early afternoon, clouds began to increase in the late afternoon and evening. There was a lot of rain over central France that was moving north all day, but from my analysis, I could tell that it would dissipate before reaching Le Mans. I saw several forecasts posted on Twitter calling for rain late Saturday and Saturday night, which never panned out. I think many of these forecasts were taken from automated weather apps that simply regurgitate model output with no human input. I'll have a post soon on why you should be careful with relying on certain apps for your weather information.
Light sprinkles arrived Sunday morning, reported to me by fans at the track through Twitter. But it wasn't enough to measure at the airport until the final hour of the race. My Thursday and Saturday forecast updates highlighted the later stages of the race for rain and mentioned that it would be sprinkles or light rain, which was accurate.
Forecasting for Le Mans was a fun challenge for me. I look forward to doing it again next year. Thanks to all who used and shared our forecasts.
