On television broadcasts and forecast maps, hurricanes appear as two-dimensional swirling vortices, belying their extremely complex three-dimensional structure. Being able to peer past the tops of clouds to see what’s happening inside a storm is critical for forecasting—particularly for catching one that is about to rapidly intensify into something more dangerous. But a key source of data that provide an x-ray-like view of that structure will shut down by June 30, just before hurricane season te...