The National Meteorological Agency (Aemet) warns Spain of a thunderstorms and showers which will affect large areas of the Iberian Peninsula until the weekend. The instability will extend more generally to the entire Mediterranean area from Wednesday until it finally affects a large part of the peninsular territory for the weekend.
This is produced by the release of a cold air mass associated with isolated depression at high levels (DANA) and the cold storm Boriswhich will head towards the Mediterranean, explains José Miguel Viñas, meteorologist at Meteored. “This retrograde movement, with the lengthening of a trough towards the west-southwest, will cause a progressive increase in atmospheric instability that will end up extending over a large part of the peninsula.”
The valley with retrograde trajectory (reverse of the usual eastward movement of the Atlantic) is approaching the Iberian Peninsula and the Balearic Islands from the northeast. On the other hand, the prediction includes the formation of depression west of Portugal. This will contribute to intensifying the breezes, which will bring greater humidity to the interior of the peninsula, explains Aemet. This phenomenon, associated with thermal and dynamic instability, will favor the formation of showers and thunderstorms, which could be strong.
On Wednesday there will be showers accompanied by thunderstorms in large areas of the eastern half. During the first half of the day they will be strong and persistent in parts of the coast of the Valencian Community and Catalonia, while in the afternoon they will extend to inland areas. They will be especially likely in Teruel and the Pyrenees, where it is not excluded that they will be accompanied by hail.
Until Thursday, the trough will continue to affect a large part of the peninsular territory and the Balearic Islands. At the same time, the supply of moisture from the Mediterranean will continue and open winds will intensify over the southwest of the peninsula. Aemet expects showers associated with thunderstorms to continue, which will be more likely in the afternoon. They will extend over a large part of the peninsular territory, with the exception of the northwest quadrant.
Locally, the showers could be of strong intensity and accompanied by a thunderstorm⛈️
Temperatures will be lower for this period, except in the southwest of the peninsula.
Given the low predictability of the situation, please follow forecast updates on our website. pic.twitter.com/E1WkuIhU2W– AEMET (@AEMET_Esp) September 16, 2024
From this point of the week, the most likely scenario for Friday 20th and Saturday 21st is that the instability is concentrated mainly in the northern half of the peninsula, although it is likely that it could extend to areas of the peninsula. center and east.
During the afternoon, showers associated with thunderstorms could be accompanied by hail. Despite the uncertainty, Aemet admitted that, for the moment, some scenarios suggest that the instability could evolve towards the northeast of the Peninsula for the rest of the weekend.
The storm “will hit particularly hard in the Valencian Community and Aragon“adds Viñas, who speaks of accumulated precipitations of up to 50 l/m2. “Thunderstorms will occur in many other areas of the peninsula as well as in the Balearic Islands, which could be locally heavy, apart from a general and marked drop in temperatures.”
