How will clouds obscure the view of exoplanet surfaces?

In 2021, NASA's next-generation observatory, the James Webb Space Telescope (JWST), will take to space. Once operational, this flagship mission will pick up where other space telescopes--like Hubble, Kepler and Spitzer--left off. This means that in addition to investigating some of the greatest cosmic mysteries, it will also search for potentially habitable exoplanets and attempt to characterize their atmospheres.