The Severe Thunderstorm Warning Services in Victoria:
The Meteorology Act of 1955 lists one the functions of the Bureau of Meteorology as:
"the issue of warnings of gales, storms and other weather conditions likely to endanger life or property."
Throughout the year, the Bureau of Meteorology provides a Severe Thunderstorm Warning Service for the whole of Victoria, including a detailed service for the Greater Melbourne metropolitian area. A Severe Thunderstorm Warning is issued when thunderstorms are expected to produce one of the following:
- Wind gusts of at least 90 kilometres per hour
- Tornadoes
- Large hail with a diameter of at least 2 centimeters
- Very heavy rain conducive to flash flooding
The location of severe thunderstorms is difficult to accurately predict well in advance. As a result, Severe Thunderstorm Warnings will generally have a lead time of no more than an hour.
The following details the content in the Severe Thunderstorm Warnings:
Severe Thunderstorm Warning - Victoria
Issued as an alert to the public, emergency services and other organisations that severe thunderstorms have developed, or are likely to develop, within a specified area over the next few hours. They generally cover a broad area (such as a Bureau weather forecast district and have a validity time up to 3 hours. Warnings will describe the most likely weather phenomena (i.e. large hail, strong winds, tornadoes or flooding rain) that will accompany the storms. All advices carry action statements that say what you can do to minimise the danger to yourself and those around.
Severe Thunderstorm Warning - Melbourne
These provide more specific information on severe thunderstorms when they are within range of Melbourne's weather radar. These warnings have duration of up to 2 hours and carry action statements on what you can do during that time.
Severe Thunderstorm Warnings are sent direct to most radio and television stations in Victoria for broadcast. The latest Warnings are also available from the Bureau of Meteorology's website.
What you can do on hearing a Severe Thunderstorm Warning:
When you hear a Severe Thunderstorm Warning broadcast for your area, take notice of the warning and treat all thunderstorms that develop during this period with caution.
State Emergency Service action statements are an important part of the warning message as they highlight actions you can take to minimise the risk of property damage, injury and death. The action statements vary according to the type of storm expected:
During all severe thunderstorms, you should:
- move indoors away from windows
- take extreme care when driving
- avoid using the telephone
If strong winds or hail are forecast, you should:
- put vehicles under cover
- beware of fallen trees and power lines
If very heavy rain and flash flooding are forecast, you should:
- keep away from creeks and drains as you may be swept away
- avoid driving through water of unknown depth