An estimate of cyclone severity is now included in all
tropical cyclone advices. The table below provides information
concerning effects due to wind which are typical of cyclones in
the various categories. Remember that the system is not designed
to give an exact statement of conditions at individual locations
but will give a general idea of the expected worst conditions.
Categories of cyclone severity range from " 1 " for weak cyclones
to "5" for the most severe cyclones. Accordingly, the risk of
property and crop damage, shore erosion and danger to life
increases from low for a category 1 to very high for a category 5
cyclone. Using this severity scale, communities will be able to
assess the degree of cyclone threat and take appropriate action.
It must be emphasized that the category refers to the severity in
the zone of maximum winds and therefore the effects felt at
individual locations may not be exactly as described in the
accompanying table.
Damage will vary from location to location depending upon factors
such as:
Tropical Cyclone Severity
Categories |
Winds |
Typical effects (indicative only) |
Category 1 |
Strongest gust less than 125 km/h |
Negligible house damage. Damage to some crops, trees and caravans. Draft may drag moorings. |
Category 2 |
Strongest gust 125 - 170 km/h |
Minor house damage. Significant damage to signs, trees and caravans.
Heavy damage to some crops. Risk of power failure. Small craft
may break moorings. |
Category 3 (eg. Winifred) |
Strongest gust 170 - 225 km/h |
Some roof and structural damage. Some caravans destroyed. Power
failure likely. |
Category 4
(eg. Tracy) |
Strongest gust 225 - 280 km/h |
Significant roofing loss and structural damage. Many caravans destroyed
and blown away. Dangerous airborne debris. Widespread power
failure. |
Category 5
(eg. Orson) |
Strongest gust More than 280 km/h |
Extremely dangerous with widespread destruction. |