Home Table of Contents

9.23 Winds - General


Back Next

Wind Type

Gusts: are a sudden but brief increase in the speed of the wind. It is of a more transient character than a squall and is followed by a lull or slackening in the wind speed. Generally, winds are least gusty over large water surfaces and most gusty over rough land and near high buildings.

Squalls: are short but furious rainstorm with strong winds, often small in area and moving at high speed, lasting longer than a gust, then often accompanied by rain. The wind speed increases by 16 knots (8 meters per second) to a peak of 22 knots (11 meters per second) or more, lasting longer than one minute.

A squall or squall line is an organised line of thunderstorms. It is classified as a multi-cell cluster, meaning a thunderstorm complex comprised of many individual updrafts. They are also called multi-cell lines. Squalls are sometimes associated with hurricanes or other cyclones, but they can also occur independently. Most commonly, independent squalls occur along front lines, and may contain heavy precipitation, hail, frequent lightning, dangerous straight line winds, and possibly funnel clouds, tornadoes and waterspouts.

Veering: as used among meteorologists explains the wind shifting in a clockwise direction (e.g. south to southwest to west). Generally pressure systems move to the east around the world, in the Southern Hemisphere the wind veers as it moves across the earth’s surface and in the Northern Hemisphere the wind backs.

Backing: as used among meteorologists explains the wind shifting in an anticlockwise direction (e.g. west to southwest to south). In the Southern Hemisphere wind backs during the passage of a cold front.