Cloud heaven over Lincolnshire today, spinning round on the monopod till I was dizzy....a few of many taken follow....

Good gracious - whatever is number two?

Great sequence Ian. Is the second one a clump of massive mammatus? And is the last a windowpane?

Yes, the first and second ones are Mammatus, it started as 'swirls, (one) and formed into a huge clump of Mammatus, (two), quite bizarre, but fascinating, last one is when I ran for cover and sheltered in the car..... :+)

That's one bruise of a mammatus. Looks about to open the heavens on you.

(And it actually looks like a face I can see dark spots for eyes, nose and mouth!)

Thanks Andrew, yes was quite an experience, have only seen Mammatus on a few occasions in the U.K..... re face, quite cryptic, but agree can see it now...