The Portuguese Institute for Sea and Atmosphere (IPMA) has updated the criteria for issuing thunderstorm weather warnings. The change aims to make warnings more representative of the dangers and impacts associated with these phenomena.
The assessment is no longer based solely on the prediction of electrical discharges but also on other severe phenomena that can accompany thunderstorms, such as intense precipitation, strong wind gusts, and hail. The new methodology jointly analyzes the spatial and temporal distribution of electrical discharges and the characteristics of associated meteorological phenomena.
Warning levels have been detailed: yellow warning considers thunderstorms with heavy rain (10-20 mm/h), hail (<2 cm), and wind gusts (70-90 km/h). Orange warning covers severe phenomena with very heavy rain (20-40 mm/h), hail (≥2 cm), and gusts (≥90 km/h). Red level is reserved for extreme phenomena with very heavy rain (≥40 mm/h), large hail, and very destructive gusts.
