Image: Jeff Kerr
Massive shelf cloud over Saskatchewan, tinged orange by the rising sun
Seeing a shelf cloud, as impressive as it might be, usually means one thing: run for cover!
Like an eyelid gently closing over the landscape – a weak shelf cloud in Swifts Creek, Victoria, Australia
Like most forbearers of bad weather, what we see from below is just the tip of the iceberg, as shelf clouds are attached to a much larger cloud system, usually bringing thunderstorms or cold fronts.
Nothing gentle here – a shelf cloud enveloping the Australian town of Wagga Wagga before bringing a thunderstorm
Roll clouds, on the other hand, are the gentle giants of the cloud world.