Lorraine Williamson
Following a period of stable, spring-like weather, Spain is set to experience significant changes due to the influence of the polar jet stream.
This atmospheric phenomenon, characterised by strong winds at altitudes of 9 to 10 kilometres, is expected to bring heavy rain, strong winds, and snowfall to various regions across the country.
Understanding the polar jet stream’s impact
The polar jet stream plays a crucial role in shaping weather patterns by acting as a boundary between cold polar air and warmer air from lower latitudes. When this jet stream shifts or undulates, it can lead to the formation of low-pressure systems, known in Spain as DANAs (Depresión Aislada en Niveles Altos). These systems are associated with severe weather events, including intense rainfall, thunderstorms, and cold conditions. The current undulations in the polar jet stream have resulted in the development of such systems, leading to the observed weather changes across Spain.
Tuesday: High waves and coastal warnings
On Tuesday, the Agencia Estatal de Meteorología (AEMET) issued yellow warnings for high waves. They are expected to range from four to five metres, affecting the coastal areas of Asturias, Cantabria, Galicia, the Basque Country, and Catalonia. Morning fog was anticipated in Girona, with winds potentially reaching up to 70 kilometres per hour in Tarragona. Light precipitation is expected in the Balearic Islands. Meanwhile, heavier and more persistent rainfall is forecasted for northern Spain and mountainous regions. Some parts of Catalonia, the Balearic Islands, and the Valencian Community may also experience heavy rain and thunderstorms. Snow levels are projected to drop to between 900 and 1,000 metres by noon. Maximum temperatures are expected to range from 10°C to 12°C in Castilla y León, with southeastern regions potentially exceeding 22°C.
Wednesday: Clearing skies and temperature fluctuations
By Wednesday, the front associated with the polar jet stream is expected to move away from Spain. However, rain may persist in the eastern Cantabrian Sea, the Pyrenees, and the Balearic Islands, with snowfall possible above 1,000 metres. Elsewhere, clearer skies are anticipated, with daytime temperatures decreasing in Mediterranean regions and rising in areas along the Cantabrian Sea.
Thursday: Renewed rain and snowfall
Thursday is forecast to bring an increase in wind intensity, accompanied by heavy rainfall in Galicia, Castilla y León, and Extremadura. Snowfall is expected at elevations between 1,200 and 1,400 metres, particularly in the Central System and the Sierra Nevada. Night-time temperatures in the Balearic Islands are likely to rise due to the arrival of mild Atlantic winds.
Friday and Saturday: Continued precipitation and slight warm-up
Looking ahead to Friday and Saturday, rain is anticipated in the northernmost parts of the peninsula, with potential precipitation extending to western and central regions. The southern peninsula, Mediterranean areas, and the Canary Islands may also experience heavy rainfall. Snow is possible at higher altitudes in Tenerife and La Palma, though forecasts remain uncertain. Temperatures are expected to rise on Friday and Saturday before declining again on Sunday.
Residents and visitors are advised to stay informed through official AEMET updates and to exercise caution, especially in areas under weather advisories.