A dust cloud over the Sahara could create a “blood rain” effect across the UK this weekend, as it turns thunderstorm-induced rains a red, forecasters have predicted.
“Blood rain” occurs when high concentrations of dust or red particles combine with rain, causing it to appear red when it falls, according to the Met Office. Red or orange rain is expected in some parts of the UK after moving across Europe, along with downpours, lightning, strong winds and hail.
The dust cloud, which originates in the Sahara, was last seen over the UK in March – causing the sky to temporarily turn orange.
A yellow thunderstorm warning has also been issued by the Met Office, which runs from Wednesday evening to the early hours of Thursday for south-east England, including London, with travel disruption likely.
The weather warning comes after the hottest day of the year so far on Tuesday, when temperatures in the southeast peaked at 27.5 degrees Celsius.
Richard Miles, from the Met Office, said: “There is currently some concentration of dust in the upper UK atmosphere that could be washed out in the rain tonight, but overall it could be a relative amount. small.
“There is a thunderstorm warning for the south-east third of England tonight and a cold front will bring wind and sometimes heavy rain to Northern Ireland and northwest Scotland this evening.
“Away from these features, it will be mostly fine and dry on Wednesday and tomorrow, temperatures could reach 23-24 degrees Celsius in London and the southeast, teenagers high or low elsewhere .”
Expected thunderstorms could cause water spray and flooding, making driving difficult and some roads closed.
There can also be delays or cancellations to train and bus services, flooding to homes and businesses, power cuts and damage from lightning strikes.
Heavy rain is expected to ease on Wednesday and Thursday in parts of Scotland and Northern Ireland, while showers will also affect areas in Wales and central and south-west England.