Severe Storms

MANAGEMENT

What is a Severe Storm

Severe storms can be divided into two types:

severe thunderstorms, and
land gales

Severe thunderstorms are defined by the Bureau of Meteorology as those thunderstorms which produce:

flash flooding; or
damaging hailstones; or
destructive wind gusts; or
tornadoes.

Thunderstorms that do not produce any of the dangerous phenomena listed above are not severe, but still may cause damage or injury through lightning strikes.
Land gales are simply gale force (62 kilometres per hour or greater) winds over the land, and usually affect a much wider area than thunderstorms.

Where and When do Storms Occur?

The frequency of land gales throughout Australia is difficult to specify, but it is generally true that in the southern half of the country extreme winds tend to occur in winter and spring.
Severe thunderstorms can occur throughout the year with the majority striking between September and March. Existing records suggest that most of the damaging storms occur in a crescent from Brisbane, through coastal NSA and Victoria to Adelaide. The most damaging individual storms have hit south-eastern Queensland and the central NSW coast.

The Warning System

The Bureau of Meteorology is responsible for the provision of warning of dangerous weather to the Australian Community, with the aim of minimising injury and damage. Warnings are prepared in the Regional Offices of the Bureau in the State and Territory capital cities, and are transmitted to authorities such as the Police, State Emergency Services and to radio and television stations.

With lifetimes of 3 hours or less and diameters of as little as 10 kilometres, severe storms are especially difficult to monitor and predict. In most States the thunderstorm warning service is confined to the capital city areas under radar coverage and aims to give at least half an hour’s notice of the onset of storms. Land gales affect much larger areas, so these warnings are issued for whole districts, throughout the country, and generally cover periods of 6 to 12 hours.

General Safety Precautions

Listen to the radio and TV for warnings, information and advice. Have a battery radio available in case of power failure. Allow a reasonable extra time margin for safety as the storm may change speed, direction or intensity within a short time.
Be Prepared. If severe thunderstorms or gale force winds are forecast for your area, store under cover, or securely fasten down loose objects such as boards, roofing iron, rubbish bins, etc. Tape up, or securely cover, large windows. Trim tree branches well clear of buildings. Place vehicle and other at risk items under cover.
When the Storm Arrives. Stay inside and shelter in the strongest part of the building. If necessary protect yourself under a strong bench or table. Keep clear of windows and large areas of glass. Find shelter if caught in the open (not under a tree).

After the Storm.

Emergency Home Page
Bomb threat
Chemical Spills
Earthquake
Fire Hazards
The First Few Mins.
Flood
Natural Hazards
Power Failure
Armed Hold-up
Severe Storms
Threatening Behaviour
Administration Back Top Property Services Home Page University of Adelaide