Weather services are watching storm Ciaran, which was due to reach Europe with dangerous wind speeds on Wednesday night. Code red has already been declared for the coast of France and Spain, but what else can we expect in Spain?
Spain is preparing for the storm ‘Ciaran’ (pronounced Kieran), which will hit the country in the form of an ‘explosive cyclogenesis’ and bring “very strong winds, violent sea storms, and excessive rainfall”. An Aemet expert put it this way: “Ciaran is not a hurricane, but the impact will be very similar”… The Spanish meteorological service Aemet therefore issued an orange and yellow warning for rain, strong gusts of wind, and adverse coastal phenomena in 10 autonomous communities.
The first half of the week has already brought rain to the northern part of the Iberian Peninsula and instability along the coasts of the Cantabrian Sea. This is a result of the storm ‘Celine’, which today gives way to ‘Ciaran’. This storm will cause unstable weather during the celebration of All Saints’ Day, especially from midday and in the northern half of Spain. Aemet warns of “a very deep storm with very strong winds, heavy sea storms, and excessive precipitation”, due to an “explosive cyclogenesis process”, with the atmospheric pressure in the center dropping by more than 24 hectopascals in less than 24 hours.
This new storm will arrive via the northwest of the peninsula and will bring heavy precipitation and thunderstorms to Galicia, the Cantabrian area, and the Pyrenees. The rain will then spread over the rest of the peninsula and the Balearic Islands but with less intensity.
The meteorological service has issued an orange and yellow warning for rain, strong gusts of wind and unfavourable coastal phenomena in areas of Aragon, Asturias, Cantabria, Castile and León, Castilla-La Mancha, Catalonia, Galicia, Navarra, the Basque Country, and La Rioja. Code red applies to the northwest coast of Spain on Thursday in the province of A Coruña. On that day, code orange applies to almost the entire region of Castilla y León, a wide strip inland on the Spanish east coast, the Costa Verde, the Balearic Islands, and the southeast coast of Andalucia. Only western Andalucia remains exempt from warnings.
Lower snow line
With the arrival of a colder air layer, temperatures will drop, leading to a significant snow line, which will be between 1000 and 1200 meters in the northern part of the peninsula. In the mountain areas, we can expect the first significant snowfall of the season, according to Aemet.
On Thursday, the presence of Ciaran will be much more dominant, causing strong winds across the country, except the Canary Islands. In mountain areas, Galicia, the Cantabrian area and points in the eastern third, speeds can exceed 100 km/h according to Aemet calculations. The day will also be marked by a heavy sea storm, especially on the coast of Galicia and the Cantabrian Sea, where waves may exceed 8 metres.
‘Celine’ will remain present on Friday, leaving an unstable atmosphere and showers, slightly more widespread than the day before, over much of the peninsula and the Balearic Islands. These could be strong with storms and hail in the northern third. Strong winds and poor sea conditions will persist, especially early on, and will decrease as the day progresses.+
New storm over the weekend
A new storm will arrive this weekend, leaving widespread rain again on the peninsula, except in the southeast and the Balearic Islands. Showers will then again be abundant in the northern half of the peninsula.
What is explosive cyclogenesis?
Explosive cyclogenesis is a weather phenomenon in which a storm becomes much stronger very quickly. This happens when the pressure at the centre of the storm drops very quickly, by more than 24 hectopascals, in less than 24 hours. It is as if the storm ‘explodes’ in a short time and becomes very powerful. This can lead to very strong winds, lots of rain and sometimes snow. It doesn’t happen very often, but when it does it can cause some pretty stormy weather.
🌀💣🌦️Es probable que la #BorrascaCiaran sufra un proceso de ciclogénesis explosiva, un concepto del que seguro has oído hablar. En este hilo explicamos qué en qué consiste. Básicamente, se trata de una borrasca que se profundiza rápidamente en poco tiempo. 🧵 pic.twitter.com/9Rttw8QqfA
— AEMET Divulga (@AEMET_Divulga) October 30, 2023