Lightning Within Hurricanes

Lightning is relatively infrequent within tropical cyclones because it requires the presence of water and ice mixing together within strong updrafts. Due to the warm core nature of tropical cyclones, there tends to not be enough mixing of water and ice to generate the charge separation required for lightning. In addition, in contrast with mid-latitude thunderstorms, the strongest parts of the updraft in tropical convection is closer to the surface where the precipitation is almost always completely liquid. When lightning does occur within tropical cyclones, it often represents a period of transition. Increased lightning activity could mean that a tropical cyclone is weakening, or it could mean a tropical cyclone is strengthening. Using other observations of the tropical cyclone, lightning activity can be assessed as to whether it is resulting in the strengthening or weakening of a tropical cyclone.

During periods of strong strengthening of a tropical cyclone, sometimes features known as convective bursts will occur. Convective bursts refer to a significant increase in convection from a strong updraft, which can result in enough mixing between water and ice particles, as well as charge separation, to generate lightning strikes.

Increased lightning activity can also indicate that a tropical cyclone may be undergoing extratropical transition, which would result in weakening of the wind field around the low pressure center. More frequent lightning is often observed in the stronger storms of the outer rainbands of tropical cyclones, farther away from the strongest portions of the warm core center.