Twenty-five years after September 11, 2001, Meteorology Matters looks back at the extraordinary weather story unfolding alongside one of the darkest days in American history.

That morning, New York City sat beneath an unusually clear post-frontal sky while Hurricane Erin churned hundreds of miles offshore. After the World Trade Center attacks, satellite imagery captured something remarkable: the enormous circulation of Erin over the Atlantic and the smoke and dust plume streaming away from lower Manhattan in the same view.

This special episode reconstructs the meteorology of September 11th, Erin’s position and intensity, the atmospheric pattern that helped carry the plume southward, what NASA satellites and astronauts aboard the International Space Station observed, and how the unprecedented shutdown of U.S. airspace created  ...