Workers at a Newport brewery were shocked after spotting what they thought was a tornado outside the site gates.
The spinning spiral was caught on camera by one staff member who was heard saying "that is mental."
Weather experts say the unusual phenomenon outside Tiny Rebel Brewing in Rogerstone, Newport, appears to be a "dust devil."A spokesman for Tiny Rebel said: "We’ve been busy brewing up a storm."It’s not very often you get to see a tornado out the window."Dust devils can reach up to more than 1,000ft tall and usually happen in dry areas with high surface temperatures.They grow up from the ground - instead of from the clouds like other tornados.A Met Office spokesperson said: "This definitely looks like a dust devil or a small tornado."Small tornadoes are not uncommon in the UK, however, they are small features often just a few metres across and lasting just a few minutes."They are a rotating column of air, caused by the rapid displacement of warm moist air by cold dense air often associated with the occurrence of active cold fronts."