Severe Weather Warning: Rissagas and Heavy Rainfall Expected in Spain
Current weather systems are impacting the Iberian Peninsula as a trough sweeps across the region, leading to severe weather warnings from the State Meteorology Agency ( Aemet ). As experts have predicted, conditions are becoming precarious, with various alerts being issued—including one concerning the risk of *Rissagas*, also known as “Meteotsunami.”
Notice by Rissagas. In addition to warnings regarding heavy rains and storms , Aemet has released coastal notices that will be in effect for several days, particularly in the Mediterranean region, including Catalonia and the Balearic Islands .
Among these alerts, one stands particularly concerning for the island of Menorca , where sea level oscillations of up to 0.7 meters are anticipated. This phenomenon, often referred to as *Rissagas* or “Meteotsunami,” exhibits similarities to seismic activity but is triggered by meteorological conditions.
Understanding Rissagas: The Meteorological Tsunami
*Rissagas*, or meteotsunamis , are characterized by sharp and sudden oscillations in sea level. According to Aemet’s previous explanations from Mª José Guerrero , the then-territorial delegate in the Balearic Islands, these occurrences are typically confined to coves and ports that possess a specific geometric configuration.
Much like traditional tsunamis, meteotsunamis can start with the sea receding, leaving small fishing and recreational boats marooned. In a matter of minutes, the waters rush back into the port with such intensity that they are capable of dragging vessels and overflowing docks .
On average, the scale of these oscillations measures around 50 centimeters; however, instances of several meters have been documented, amplifying their potential danger.
Meteotsunami differs substantively from a standard tsunami in that its origins are meteorological, not seismic. Aemet outlines that these occurrences stem from small but rapid changes in atmospheric pressure (ranging from 1-3 hectopascals), resulting from the movements of weather fronts, gravitational waves, and other convection-related phenomena.
Aemet’s Alerts: Types and Impact
First Red Notice from Aemet. Today’s forecasts indicate serious implications exceeding coastal risks. Aemet has warned of strong showers and storms , which may reach particularly intense levels— locally very strong . These adverse conditions are expected to affect sizeable regions of Catalonia , the Pyrenees , the northern parts of the Valencian Community , and the eastern regions of the Iberian System .
The agency has issued different alert categories across the center and northern Mediterranean coastline, including a red notice (indicating extreme risk) for the central areas of Barcelona , where rainfall could accumulate to 60 mm within the hour and potentially reach 120 mm over three to four hours.
Impending Changes in Weather
In addition to the red warning indicating extreme risk, numerous orange notices (signifying important risk) will be in effect today and tomorrow. These pertain to the risks posed by rain and storms. Although conditions are expected to ease by Friday , isolated storm activity may continue throughout that day.
As Spain grapples with these environmental challenges, the interplay between heat and humidity indicates the need for preparedness among communities. The current weather events are a reminder of the volatility of nature and reinforce the importance of monitoring meteorological updates closely.
To stay informed, individuals are urged to follow Aemet announcements and prepare accordingly, especially those residing in affected coastal areas. As weather patterns continue to evolve, it is essential to remain vigilant and responsive.
Image credit: Menorchin / Aemet