Water vapor is a small but significant constituent of the atmosphere, warming the planet due to the greenhouse effect and condensing to form clouds. As moisture-laden air rises, the relative humidity increases until it saturates the air, at which time precipitation occurs. If the uplift of air is due to strong updrafts and unstable air systems, as in thunderstorms, then the precipitation is called convective. This animation shows the convective precipitation for the whole globe from September 1, 2004, through September 5, 2004, during the period of Hurricane Frances in the western Atlantic Ocean and Typhoon Songda in the western Pacific Ocean. Convective precipitation is more intense but less long-lasting than large-scale precipitation.
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