If you own a car then you’ve probably been cursing that layer of fine dust that you found all over it over the weekend. It’s not just any old layer of dust, however, because it’s traveled all the way from the Sahara desert, falling out in the showers of rain of the past 24 hours.
The image below is a Dust RGB image from Eumetsat, taken at 1800 GMT on Saturday (29th March). This type of imagery filters certain wavelengths to show up dust as a bright pink colour. We can clearly see how a thick plume of dust is being whipped up through eastern Algeria and blown towards the Mediterranean. This dust has made the 3,000 km trip to Ireland in strong southerly winds created between low pressure to the west of Iberia and high pressure over the eastern Med.
As it was carried along at a height of around 3,000-4,000 m it became entrained into weather systems, allowing it to be washed out in the rain that fell here overnight. The rain evaporated off and we were left with the specks of dust.
It does occasionally happen that this dust reaches as far north as Ireland and even Iceland, and indeed it can reach as far west as the Caribbean Sea, where it can put a dampener on hurricane activity. We could see some more of it during the next couple of days as the setup remains favourable for southeasterly winds, so don’t wash the car just yet!