User:AHeneen/Sandbox/Tropical Cyclone Safety
Tropical Cyclones, known regionally as "cyclones", "hurricanes", or "typhoons", are a grave danger in many coastal areas of the world, particularly Eastern Asia, the Caribbean, the Southeastern United States, Southeastern Africa, and Northern Australia and other parts of Oceania.
Understand
editTropical cyclones are large storms which generate over warm waters and produce very high winds, heavy rainfall, and a feature known as storm surge—a high level of water, similar to a tide, created by the lower air pressure. Tropical cyclones are often among the most powerful storms on earth, rivaled only in scale and intensity by European Windstorms & certain Arctic lows.
Regional Terminology
editTropical Cyclones are known by several names, depending on both the basin and its windspeed.
North America
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Saffir-Simpson Scale
The intensity scale used in the North Atlantic and Eastern Pacific, known as the "Saffir-Simpson Scale," is based on maximum 1-minute wind speed averages:
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In the North Atlantic Ocean and Eastern Pacific, tropical cyclones affect the Caribbean, Central America, Bermuda, and the eastern coast of the United States. Tropical storms and hurricanes infrequently impact the U.S. coast north of North Carolina, Canada (where hurricanes are often fast-moving and not significantly different from severe winter storms), Cape Verde, or the Azores. Tropical cyclones almost never impact the Atlantic coast of Africa, Europe, or South America.
The primary agency for monitoring tropical cyclones in the region is the US' National Hurricane Center in Miami, . Meteorological agencies in other countries may issue their own forecasts and warnings, but will rely on data and bulletins provided by the NHC. The official 'seasons' for tropical storms in the Eastern Pacific is 15 May-30 November and in the Atlantic runs from 1 June-30 November.
Western Pacific
editThis region is monitored primarily by the Japan Meteorological Association in Tokyo, with individual nations' weather services monitoring storms. The unnamed intensity scale is based on 10-minute wind speed averages:
- Typhoon — Maximum sustained winds in excess of 118km/h
- "Super Typhoon" is commonly used to refer to typhoons with max. sustained winds in excess of 241km/h. This term, however, is based on reports by the US Navy's Joint Typhoon Warning Center which uses a 1-min. average for wind speeds (which is inevitably higher than official reports)
- Severe Tropical Storm — Maximum sustained winds of 89-117 km/h.
- Tropical Storm — Maximum sustained winds of 62-88 km/h.
- Tropical Depression — Maximum sustained winds below 62 km/h.
North Indian Ocean
editThis region is monitored by the Indian Meteorological Association in New Delhi. The unnamed intensity scale is based on 3-minute wind speed averages:
- Super Cyclonic Storm — Maximum sustained winds above 222 km/h.
- Very Severe Cyclonic Storm — Maximum sustained winds 118-221 km/h.
- Severe Cyclonic Storm — Maximum sustained winds 88-117 km/h.
- Cyclonic Storm — Maximum sustained winds 62-87 km/h.
- Deep Depression — Maximum sustained winds 52-61 km/h.
- Depression — Maximum sustained winds below 52 km/h.
Southwest Indian Ocean
editThis region is monitored by Météo-France in La Réunion. The unnamed intensity scale is based on 10-minute wind speed averages:
- Very Intense Tropical Cyclone — Maximum sustained winds above 212 km/h.
- Intense Tropical Cyclone — Maximum sustained winds 166-212 km/h.
- Tropical Cyclone — Maximum sustained winds 118-165 km/h.
- Severe Tropical Storm — Maximum sustained winds 89-117 km/h.
- Moderate Tropical Cyclone — Maximum sustained winds 63-88 km/h.
- Tropical Depression— Maximum sustained winds 51-62 km/h.
- Tropical Disturbance — Maximum sustained winds below 51 km/h.
Australia Region
editThis region, including the Indian Ocean east of 90ºE and Pacific Ocean south of 0º, is monitored by the Australian Bureau of Meteorology, Tropical Cyclone Warning Center in Jakarta, & the Regional Specialized Meteorological Station in Nadi. The Australian Tropical Cyclone Intensity Scale is based on BOTH maximum estimated maximum wind gusts AND 10-minute wind speed averages:
- Category Five Severe Tropical Cyclone — Maximum sustained winds above 200 km/h and maximum estimated wind gusts above 279 km/h.
- Category Four Severe Tropical Cyclone — Maximum sustained winds 160-200 km/h and maximum estimated wind gusts 225-279 km/h.
- Category Three Severe Tropical Cyclone — Maximum sustained winds 118-159 km/h and maximum estimated wind gusts 165-224 km/h.
- Category Two Tropical Cyclone — Maximum sustained winds 89-117 km/h and maximum estimated wind gusts 125-164-225 km/h.
- Category One Tropical Cyclone — Maximum sustained winds 63-88 km/h and maximum estimated wind gusts 91-124 km/h.
- Tropical Low (Australia) or Tropical Depression (Indonesia/S.Pacific) — Maximum sustained winds below 63 km/h and maximum estimated wind gusts below 91 km/h.
Plan ahead
editWhen planning travel to a region affected seasonally by tropical cyclones, it is important to prepare a backup plan. In nearly all cases, the best plan is to move inland.
Tropical cyclones feed off warm ocean waters and weaken over land. The most dangerous facets of the strom are the storm surge--wind driven water that floods the coast at landfall--and wind--which decreases as the storm stays over land. The largest problem inland is flooding--especially in regions not prone to large amounts of rain.
When planning the backup plan, keep in mind that forecasting tropical cyclones is a very inaccurate science as there are countless aspect which affect where the TC will make landfall. Often times forecasts 3-4 days away from landfall may be hundreds of kilometers off. Keep in mind also that tropical cyclones vary in width from a hundred kilometers to nearly a thousand kilometers, so the effects can be felt over a wide region. One of the most notable tropical cyclones of recent time, Hurricane Katrina, wrought devastation over an area of 90,000 square miles (about 230,000 square kilometers)!