A storm, start to finish

Three tropical storms at three stages of life, and one melt season from beginning to end.

Weather satellites photograph the same half of the planet every few minutes, so a storm can be followed from the first loose cluster of clouds to the moment it reaches land. No single film here shows a whole storm. Put together, three different storms cover the stages one after another.

Hurricane Erin shows the beginning: a tropical wave off Africa organising around one centre. Super Typhoon Bavi shows a storm at full strength, with a clear eye. Hurricane Polo shows the end, as a storm approaches and crosses a coast. The Arctic film finishes the series at a longer scale: not one storm but one season, from the March ice maximum to the September minimum.