An astronaut onboard the ISS saw this Cumulus congestus cloud looming over the Arabian Peninsula, surrounded by a gathering of small Cumulus, like a shepherd stooped over her flock.
The clouds are forming along the shore of the Persian Gulf, where the desert meets the sea. Perhaps an onshore wind is drawing moisture in over the arid land to rise rapidly in the heat and develop into the towering formation? The darkness of the tall shadow, contrasting with the glittering sea surface on the bottom right, shows just how relentlessly the Sun beats down on the Persian Gulf. Here, the air of the lower atmosphere tends to sink – something we describe as persistent high pressure – which makes flocks of Cumulus clouds a rare sight indeed.
This Cloud-a-Day was suggested by Fleur Wilders (Member 54,145).
NASA
