The storm that caused damage over the weekend in the regions of Albergaria-a-Velha and Oliveira de Azeméis was caused by a downburst, a meteorological phenomenon that originated hail, thunder and intense heavy rain. The hail stones reached about two centimeters in diameter.
The phenomenon surprised the population by occurring still in full summer, when this type of severe storm would not be expected. Many residents were caught off guard by the violence of the storm.
The IPMA, Portuguese Institute for the Sea and the Atmosphere, was the entity responsible for explaining and confirming that it was indeed a downburst. This phenomenon occurs when a mass of cold air descends rapidly towards the ground, spreading violently in all directions and causing destructive wind gusts, in addition to intense rain and hail.
