Sahara Rain

It sounds like a name for a New Age band, or at least a track from a meditation CD but Sahara Rain is a genuine weather phenomenon.

Sahara Rain-drops on my car.

I first encountered it as a child in 1960 when I lived in Southampton. Only a few households owned a car in those days so they were kept spotless and if my father was not cleaning his, he was under the bonnet tinkering with valves and tappets. On that spring morning there was fog and all of the cars in the street had blobs of red, granular mud on them. Probably through the BBC Home Service or the Southern Evening Echo, the grown-ups found out that the mud was composed of sand from the Sahara and it was christened "Sahara Rain".

The North African desert expanded through the sixties and sand-storms became a common feature. A fierce updraft over the Atlas Mountains send the dust high into the atmosphere where it spread northwards. 2000 miles further on, the dust was descending over the UK as a sort of haze but much of it was transported upwards again inside thunder-clouds where it combined with water droplets to form hail and rain that fell in brief showers characterised by large, well-spaced raindrops, each containing hundreds of grains of sand.

Hazy sunshine on Thursday.

It all happened again this week over southern Britain and parts of Ireland. We had a shower of yellow Sahara Rain early on Tuesday morning followed by several windless days of haze. Pollution levels in the South East measured 10 on a scale of 1 to 10, maybe all the way up to 11! Hospitals have been inundated with patients complaining of respiratory problems such as asthma after breathing in a cocktail of dust and pollen mixed with nano-particles from diesel engines.

The air is getting cleaner now as trans-Atlantic weather reaches the west of Britain, but in East Anglia wet still feel grimy.