Hurricane Terms - I

I

INCHES OF MERCURY (Hg): The name comes from the use of mercurial barometers that equate the height of a column of mercury with air pressure. One inch of mercury is equivalent to 33.86 millibars or 25.40 millimeters.

INLAND HIGH WIND WARNING FOR HURRICANE FORCE WINDS: Announcement issued for force winds 74 mph (64 knots) or greater within 12 hours.

INLAND HIGH WIND WATCH FOR HURRICANE FORCE WINDS: Announcement issued for hurricane force winds 74 mph (64 knots) or greater within 24 hours.

INSTABILITY: Occurs when a rising air parcel becomes less dense than the surrounding air. Since its temperature will not cool as rapidly as the surrounding environment, it will continue to rise on its own. Contrasts with stable air.

INTERTROPICAL CONVERGENCE ZONE (ITCZ): The axis dividing the southeast trades from the northeast trades, toward which the surface winds tend to converge The easterly trade winds of both hemispheres converge at an area near the equator called the "Intertropical Convergence Zone (ICTZ)", producing a narrow band of clouds and thunderstorms that encircle portions of the globe.

ISOBAR: The line drawn on a weather map connecting points of equal barometric pressure.

Contact us to help make your house, property, or business hurricane storm prepared.