The following is a glossary of tropical cyclone terms. A Advisory Official information issued by tropical cyclone warning centers describing all tropical cyclone watches and warnings in effect along with details concerning tropical cyclone locations, intensity and movement, and precautions that should be taken. Advisories are also issued to describe: (a) tropical cyclones prior to issuance of watches and warnings and (b) subtropical cyclones. B Bar This is used to describe a dark layer of clouds that precedes the approach of a tropical cyclone. It is usually followed by heavy precipitation, and can also been seen in the eyewall of a cyclone. The arrival of the storm is often determined by this bar, as barometric pressure begins to fall and conditions begin to deteriorate following its passage. Best track A subjectively-smoothed representation of a tropical cyclone's location and intensity over its lifetime. The best track contains the cyclone's latitude, longitude, maximum sustained surface winds, and minimum sea-level pressure at 6-hourly intervals. Best track positions and intensities, which are based on a post-storm assessment of all available data, may differ from values contained in storm advisories. They also generally will not reflect the erratic motion implied by connecting individual center fix positions. C Center Generally speaking, the vertical axis of a tropical cyclone, usually defined by the location of minimum wind or minimum pressure. The cyclone center position can vary with altitude. In advisory products, refers to the center position at the surface. Center / Vortex Fix The location of the center of a tropical or subtropical cyclone obtained by reconnaissance aircraft penetration, satellite, radar, or synoptic data. Central Dense Overcast A dense mass of clouds that covers and eyewall or the most tightly curved inner bands of a tropical cyclone. Central North Pacific Basin The region north of the Equator between 140W and the International Dateline. The Central Pacific Hurricane Center (CPHC) in Honolulu, Hawaii is responsible for tracking tropical cyclones in this region. Coriolis force The fictitious force that causes the apparent deflection of an object that is moving in a straight line in an inertial reference frame as perceived by an observer in a rotating reference frame. The effect of this force is at its minimum at the equator and increases away from it. In the synoptic scales of the atmosphere, the Coriolis force will cause flow flowing towards a low pressure area to deflect perpendicularly to the