Where and when do tropical cyclones occur?
++++++++++++++++++++++++++++++++ For an introduction to tropical cyclones, click here. For definitions of tropical storms and tropical cyclones, click here. For information about the names of tropical cyclones, click here. ++++++++++++++++++++++++++++++++ Tropical cyclones occur more frequently over the western part of the North Pacific Ocean (including the China Seas) than anywhere else, the average number of typhoons per year being about 20. The average number of tropical storms which form over this region each year but do not reach cyclone intensity (i.e. sustained winds at least 64 knots) is about ten. Typhoons can occur at any time during the period June to December but are most likely to do so in August, September and October. Most typhoons originate in the area bounded by the parallels of 5 and 20N and the meridians of 125 and 170E, with the most productive part of this area near the Caroline Islands (5 to 10N, 140 to 160E). Vigorous convection over these and other islands, as a
