Graphical Severe Weather Warnings in South Australia

Severe Weather

Severe Weather warnings are provided for potentially hazardous or dangerous weather that is not directly related to severe thunderstorms, tropical cyclones or bushfires.

In South Australia, severe weather warnings are provided for

• Sustained winds of gale force (63 km/h) or more.
• Wind gusts of 90 km/h or greater. 
• Very heavy rain leading to flash flooding. 
• Abnormally high tides (or storm tides) in Gulf St Vincent and Spencer Gulf.

Severe Weather Warnings for South Australia

The Bureau of Meteorology issues Severe Weather Warnings whenever severe weather (as defined above) is occurring in an area or is expected to develop or move into an area. The warnings describe the area under threat and the expected hazards. Warnings are issued with varying lead-times, depending on the weather situation, and range from just an hour or two up to about 24 hours.

Warnings are distributed widely to the media and emergency services, and are available to the public via the internet and various telephone and fax-based services. A coloured image is available with the warning on the internet, which shows the area at risk in map format. This service is provided for all parts of South Australia.

Here is an example, which shows what these warnings look like.

EXAMPLE ONLY IDS65503 Australian Government Bureau of Meteorology South Australia Regional Office TOP PRIORITY FOR IMMEDIATE BROADCAST SEVERE WEATHER WARNING for DAMAGING WINDS AND FLASH FLOODING For people in the Adelaide and Mount Lofty Ranges, Lower Eyre Peninsula, Kangaroo Island, Yorke Peninsula, Mid North, Riverland, Murraylands, Upper South East and parts of the Eastern Eyre Peninsula districts. Issued at 1:45 pm Thursday, 28 June 2007. A small but deep low just south of Kangaroo Island is moving slowly eastwards. The low is expected to cross the Coorong coast tonight, then weaken as it moves further inland towards the Victorian border. West to southwest winds, averaging 50-70 km/h with peak gusts to 120 km/h are already affecting parts of Eyre and Yorke Peninsulas and these damaging winds are expected to spread across the warning area during this afternoon. The winds should start easing after midnight. Locations which may be affected include Adelaide, Port Lincoln, Maitland, Murray Bridge and Victor Harbor. Areas of rain and showers are occurring across the southern half of the state. The rain is forecast to become heavy later this afternoon in the Mid North and Mount Lofty Ranges, especially on and along the western slopes of the ranges. Rainfall totals of 100-150 mm are possible and this may cause flash flooding. The State Emergency Service advises that people should: * Move vehicles under cover or away from trees * Secure or put away loose items around your property. * Don't drive, ride or walk through flood water. * Keep clear of creeks and storm drains. * Stay indoors, away from windows, while conditions are severe. The next warning is due to be issued by 4:45 pm. Warnings are also available through TV and radio broadcasts, the Bureau's website at www.bom.gov.au or by calling 1300 659 215. The Bureau and State Emergency Service would appreciate warnings being broadcast regularly.

Important things to note:

Legend

The area covered by the Warning is shaded yellow and represents the area where there is a potential threat from severe weather. The area may consist of all or part of one or several weather forecast districts.

Issue time

The issue time is the time that the Bureau of Meteorology transmitted the Warning. It is displayed near the top of the warning text and also in the top right hand corner of the map, in local South Australian time; that is Central Standard Time (CST) or Central Daylight Savings Time (CDT).

Validity Period and Update Frequency

Severe weather warnings in South Australia are valid for up to 24 hours. The warnings are updated at least every 3 hours, but more frequently if the situation warrants. The expected issue time of the next Warning is given in the text.

Districts

The divisions on the chart indicate the boundaries of the Bureau’s weather forecast districts. Districts are labelled with an abbreviation, as follows: