More dust could return to the Mediterranean by Friday
According to Spain’s national weather agency Aemet, a spell of “blood rain” is forecast to hit parts of southern Spain this week. The weather phenomenon is expected as unsettled conditions happen alongside a surge of Saharan dust.
Aemet said a shift in atmospheric conditions is driving low pressure systems and cold air at altitude into the west of the peninsula, creating a highly unstable setup. The Saharan dust is already spreading across Andalucía and local news site The Spanish Eye reports the dust will spread further into the peninsula and the Balearic Islands over the coming days.
Today, Wednesday, April 28, dust concentrations will be at their highest across much of southern Spain, including Andalucía, as well as central areas and the Mediterranean coast. The dusty conditions are expected to linger until at least Thursday.
Forecasts from Aemet suggest more dust could return to the Mediterranean by Friday. It comes as a series of alerts have been issued for heavy rain in Andalucía this week. Areas of Spain under weather warnings for storms today include Andalucía, Aragon, Castilla y Leon, La Rioja, Galicia and Pais Vasco.
The UK Met Office said blood rain is not actually a meteorological or scientific term. In the case of blood rain, strong winds or storms can whip up dust and sand. As this becomes airborne it can get caught up in atmospheric circulation, where it can be carried for thousands of miles.
Eventually the dust will either fall out of the sky due to gravity or will be caught up in rain clouds, where it mixes with the water droplets.
When these fall as rain the raindrops could appear red. The colour can vary from a faint rusty hue to deeper reds, depending on how much dust is present in the atmosphere at the time of rainfall.
Powerful atmospheric systems such as thunderstorms, strong surface winds or large‑scale weather patterns can lift sand and dust from desert regions into the air. In the UK, documented cases of truly red rain are extremely limited. What the UK normally experience instead is rain that washes dust out of the atmosphere in small amounts.
The Met Office said parts of Spain and France seen temperatures “well above” average this month. Areas of Europe reached high 20s or low 30s last week.
The UK national weather forecaster said: “These temperatures are more typical of summer and unusual for April, driven by a southeasterly flow pulling warm air northwards from Africa.”
Aemet put out a warning on its X account last week saying that “the air masses currently over Spain are extremely warm”. The forecaster said: “This is an episode of summer-like heat in April.”
