These odd quirks are thanks to temperature inversions in the atmosphere, where warmer air high above traps cooler air close to the ground.

It is an explosive mix - when it hits a cold front of cooler air it causes thunderstorms.

But the hot air also set off ferocious thunderstorms as it collided with cooler air.

Outside in the cooler air of the Edwardian atrium the sound of cellphone conversation surrounds them as Stefan turns and goes.

The clouds grew taller, pushing through the cooler air above until they developed into giant cauliflowers heads of cumulus calvus.