Every year the North Queensland coast feels the affects of Tropical
Cyclones. These are in principal the same as hurricanes, typhoons
and monsoons. Basically a tropical cyclone is a huge mass of low
pressure air that forms over warm tropical water swirling in a clockwise
direction. As the air mass grows strong winds and torrential rain
result. If large enough the winds can be very destructive.
The
cyclone season in Cairns lasts from November to May. Whilst cyclones
can produce strong winds they rarely do more than disrupt traffic
and boat movements for a few days.
The
severity of a cyclone can be measured by the following table.
Category
|
Strongest
wind gust
(kilometres per hour) |
Typical
effects |
1
|
125 |
Negligible
house damage. Damage to some crops, trees and caravans. Boats
may drag anchors. |
2
|
125
- 169 |
Minor
house damage. Significant damage to signs, trees and caravans.
Heavy damage to crops. Risk of power failure. Small craft may
break moorings. |
3
|
170
- 224 |
Some
roof and structural damage. Some caravans destroyed. Power failure
likely. |
4
|
225
- 279 |
Significant
roofing loss and Structural damage. Many caravans destroyed
and blown away. Dangerous airborne debris and widespread power
loss. |
5
|
More
than 280 |
extremely
dangerous with widespread destruction. |
|