Reports of ‘blood rain’ in the UK have been circulating in the news in recent days, although the reality is a little more underwhelming.
There have been some reports in recent days of a yellow haze to some recent rain and thunderstorms, especially in the southeast. Forecasters at the Met Office are able to monitor satellite imagery and the recent yellow tinge to some rain is likely due dust picked up in northern Africa, before falling with the thundery downpours.
Met Office Chief Meteorologist Paul Gundersen said: “Concentrations of dust in the recent system – which has now moved away from the UK – were relatively low so would have quickly been rained out and washed away.
“It’s not uncommon to have some dust particles mixed in with the rainfall when the source air comes from northern Africa. The most common impact of this can be a dusty film sometimes appearing on people’s cars.”
Source air for the weather over the UK is shifting over the next few days, so the chances of dust particles being mixed in with the rain is reduced.
Paul said: “Whereas we were previously inviting warm air in from the south, the next few days will see the air over the UK have more of a marine origin, which reduces the chances of dust being mixed in with the rain and giving that bit of a yellow haze.”
However, early next week, signals suggest the return of a southerly flow, bringing with it the chance of some dust to be mixed in with the rain. Will that mean ‘blood rain’? Probably not.
Paul said: “There’s a chance of some dust being rained-out in the southeast early next week, but any amounts of dust would be relatively small and would likely be soon washed away.”
What is ‘blood rain’?
‘Blood rain’ – as it’s colloquially called – occurs when high concentrations of red coloured dust gets mixed in with rain, giving it a red appearance as it falls.
True blood rain in the UK is very rare, despite what some headlines suggest. Yellow and brown dust in fairly low concentrations can be more common in the UK, largely resulting in a film of dust after a rain shower, but any visual impacts on the rainfall are generally minor and fairly short-lived.