Certain upwind patterns produce distinctive smells.

Many those believe that they can smell the weather, particularly earlier a thunderstorm hits. Experts facts that these relatives might be smelling ozone, a type of oxygen that can be produced by lightning. In addition, rainy weather is often accompanied by humidity, which enhances the ability to smell the environment. High winds and raindrops also stir up and transport the scents of both innate and man-made substances, as asphalt, trees and vegetation.

Certain weather patterns send out distinctive smells.

Source: http://feeds.wisegeek.com/~r/learn-something-new-every-day-rss/~3/vsaFUKSRHII/can-people-smell-the-weather.htm