What is 'blood rain'? Weather forecasters warn thunderstorm and dust phenomenon headed for UK

The UK could be showered with 'blood rain' within days as this week's heavy thunderstorms mix with a dust cloud, forecasters say. Tinted rain could fall in some parts of the country this week, as downpours, lightning, strong winds and hail move in. According to the Met Office, the 'blood rain' phenomenon can occur when relatively high concentrations of red coloured dust or particles get mixed with rain, giving it a red, orange or yellow appearance as it falls.

The weather forecaster has explained that strong winds or storms can whip up dust and sand, which can get caught up in atmospheric circulation as it becomes airborne and be carried for thousands of miles.

But experts have explained the so-called 'blood rain' that periodically falls in the UK is unlikely to be the rich-hued red rarely seen around the world.

Blood rain, which is a colloquial rather than scientific term, is usually closer to a yellow or orange colour, according to the Met Office.

That is because it is unusual for dust to travel in high enough concentrations to tint the downpours a deep claret.

References to 'blood rain' occur throughout history, including in Homer's Iliad.

In a contemporary example, monsoon rains that drenched the southern Indian state of Kerala in 2001 periodically fell with a red colour which was dark enough to stain clothes.

The Met Office has previously explained that each year on several occasions the UK will see rain falling with some amount of dust mixed into it - usually coming from a Saharan dust cloud.

However, the dust is usually yellow or brown and in very low concentrations - usually more likely to be spotted in a thin film of dust on people's cars or windows after the water has evaporated than in rainfall itself.

Will blood rain fall in the UK this week?The prospect of a blood rain spectacle in the UK this week comes after a yellow weather warning for thunderstorms, which brought heavy rain and lightning to the the capital and south east late overnight Wednesday, at the same time as a dust cloud lingers in the atmosphere.

Earlier this week, Richard Miles, of the Met Office, told the PA news agency: “There are some dust concentrations in the atmosphere above the UK at present which might well be washed out in the rain tonight, but it’s likely to be relatively small amounts on the whole.

“There’s a warning out for thunderstorms for the south-eastern third of England tonight, and a squally cold front will bring wind and sometimes heavy rain to Northern Ireland and north west Scotland this evening.

“Away from these features it will be mostly fine and dry today and tomorrow, temperatures up to 23-24C in London and the South East, high teens or low 20s elsewhere.”

Heavy rain is due to fall in parts of Scotland and Northern Ireland, while showers will also hit areas in Wales and central and south-west England on Thursday (19 May).

The Met Office says residual cloud and showery rain should also be clearing far southeast of England, whereas it should be dry with sunny spells and feeling warm in the south and east. It is forecast to be windy and cloudy in the far northwest with some showery rain at times, moving into NI later.Into Thursday evening, there will be clear spells elsewhere before cloud increases and brings some patchy rain northwards into southern England.

Patchy rain should hit the south on Friday, clearing during the morning. The forecaster says there should be a bright start elsewhere, with a rain band moving across NI and west Scotland, before turning showery across rest of UK.

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