New night heat warnings
- Servei Meteorològic de Catalunya, Barcelona, Spain (santi.segala@gencat.cat)
In the recent decades, extreme hot days and heat waves have been one of the main meteorological dangers that have affected mediterranean regions. In 2009, the Meteorological Service of Catalonia (SMC) implemented heat warnings using a specific threshold for every municipality. These thresholds were calculated from a study that was conducted in coordination with the Public Health Agency (ASPCAT) and the Directorate-General for Civil Protection and Emergencies (DGPCE), based on finding the correlation between high temperatures and mortality. A turning point in mortality appeared around the 98th percentile of the maximum daily temperature during the summer period, so that was the threshold adopted. That is, only 2% of the days during that period exceed the considered value.
Heat warnings have been operational since 2009, but due to the increase in the number of tropical nights (minimum temperature above 20 ºC) and torrid nights (temperature above 25 ºC) and knowing the relationship between high night-time temperatures and the aggravation of heat-sensitive health effects during the night, SMC and DGPCE decided to establish new warning thresholds for Meteorological Situation of Danger (SMP) due to night heat.
The new thresholds that have been set are as follows:
- Low Level Warning, intense nocturnal heat, defined when the minimum temperature exceeds the 98th percentile of the night-time minimum temperature from June to August.
- High Level Warning, very intense nocturnal heat, defined if the minimum temperature is higher than the 98th percentile of the night-time minimum temperature from June to August plus two degrees Celsius.
Like other operational warnings in Catalonia, the new system consists of six degrees of danger. These warnings are issued for each county that constituted this region, with a time interval of 6 hours and are updated twice a day. These warnings are sent to Civil Protection who are responsible for managing and coordinating actions aimed at protecting people, property, and the environment. Simultaneously, these warnings are made available for everyone on the website and social media platforms.
In 2023, this new night heat warning in Catalonia operated as a pilot project and it belongs to the meteorological emergency system from now on.
How to cite: Segalà Gallofré, S., Aran Roura, M., Brucet Vinyals, C., Gallego Santiago, S., and Serra Uró, A.: New night heat warnings, EMS Annual Meeting 2024, Barcelona, Spain, 1–6 Sep 2024, EMS2024-309, https://doi.org/10.5194/ems2024-309, 2024.
