Refer to figure.
TROPICAL REVOLVING STORMS (TRS).

These usually begin as tropical depressions (wind speeds less than 33 kt), and develop over warm tropical oceans into tropical storms (wind speeds from 34 to 63 kt). When they develop further and sustain wind speeds greater than 63 kt, they are designated tropical revolving storms (TRS), which are named either hurricanes, typhoons or cyclones, depending on the area of the world.

HURRICANES:

• Northern Hemisphere – Atlantic and Eastern Pacific
• Occur approximately 6-7 times per year
• Mainly from July to November

CYCLONES:

• Southern Hemisphere – Western Pacific, including Australia (also previously referred to as “Willy- Willy”) - approx. 9 per year
• East coast of Africa
• Mainly from December to April

CYCLONES:

• Indian Ocean
• Occur occasionally (approx.12 times per year) March – December, mainly April – May and October – November.

TYPHOON:

• Northern Hemisphere (Western Pacific) and South Chinese Sea. (Japan, Korea, Chinese Coastline, Taiwan)
• Area with highest frequency of TRS (20 times per year)
• Mainly from June to November