Rapid Intensification

Rapid intensification is the intensification of a tropical cyclone's maximum sustained wind speed by 25 knots (30 mph) within a 24-hour period. There is no forecast for the rapid intensification of hurricanes. While research continues, an exact understanding of the physics involved in triggering these events does not now exist.

As a result, hurricanes can go from being relatively stable in their intensity to intensifying suddenly and without notice. Any storm, regardless of its prior history or the imminence of its landfall, has the potential to intensify by two Saffir-Simpson categories or more in a matter of a few hours, including during the overnight hours.

As a storm becomes more intense and its winds increase in speed, its central pressure plummets - its low pressure center "deepens" - thus rapid intensification is sometimes also called "rapid deepening." The greater part of the uncertainty in the intensity forecast is accounted for by this phenomenon. It is easier to predict the top wind speeds of gradually intensifying storms than it is for storms which undergo rapid intensification.

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