On Friday, a pronounced plume of Saharan dust is moving north-west over the western Mediterranean and reaching south-eastern Spain. According to the state weather agency AEMET the main concentration will be over coastal areas of eastern Andalucía, the Región de Murcia and the Comunidad Valenciana. On Thursday, a light Islas Baleares was already observed on Calima .
Dust concentrations are expected mainly in higher layers of the atmosphere. This will produce hazy skies and reduced visibility over long distances, while at ground level pollution is currently expected to remain mostly moderate. However, raindrops in showers can trap particles and carry them down to the surface. Muddy rain is therefore possible locally, visibly dirtying vehicles and façades. The extent of this effect depends on rainfall intensity, the vertical distribution of dust and wind direction, and can vary significantly over short distances.
Meteorologist Evelio Gómez by Meteored describes the end of August as changeable weather-wise: thunderstorms at the start of the week were followed by Atlantic fronts bringing slightly cooler air; now the dust plume from North Africa is also affecting conditions along the east and south-east coasts. Regional forecasts suggest local showers and isolated thunderstorms on Friday, which may help dust particles fall out of the air. Without rain, the dust layer will remain mostly aloft and will mainly be noticeable at ground level as a visual haze.
When fine-particle levels near the ground are significantly elevated, health services generally advise people to take precautions. AEMET and regional analysis centres currently expect, however, that dust levels will be higher mainly in the upper atmosphere. Sensitive people may experience respiratory irritation in visibly hazy, dry conditions; reducing strenuous outdoor activity for a short time is advisable in such cases.
AEMET says it will provide regularly updated maps and advice on Friday. As the plume’s position and density depend on mesoscale airflows, conditions should be checked again in the morning. The key factor is whether and where showers occur: this will determine whether the dust largely remains aloft or falls as muddy rain. Coastal areas in Andalucía, the Región de Murcia and the Comunidad Valenciana are likely to be most affected; on the Islas Baleares, the Calima is expected to ease during the day.
Editor: Andreas M. Brucker (Article created with AI assistance).