|The Edge of Typhoon Halong from the International Space Station|
by Alexander Gerst (ESA/NASA), July 31, 2014
A third of all tropical storms occur in the northwest Pacific Basin.
Tropical storm intensity is categorized by sustained wind speed ranges by the Regional Specialized Meteorological Center. Typhoons have wind speeds ranging from 73 to 97 miles per hour.
|Severe Tropical Storm||48–63 knots
|Tropical Storm||34–47 knots
|Tropical Depression||≤ 33 knots
≤ 38 miles/h
Conditions for typhoon development are:
- Warm ocean surface temperatures;
- Atmospheric instability;
- High humidity in the lower to middle level of the troposphere;
- Sufficient Coriolis force to develop a low pressure center;
- Pre-existing low level disturbance; and
- Low vertical wind shear.
- the Cantonese t'ai fung meaning great wind;
- the Arabic tufan meaning smoke; or
- the Greek typhon meaning monster.
- How do tropical cyclones form? NOAA Hurricane Research Division.
- Typhoon, Meteorology Glossary, American Meteorological Society.
- Typhoon, Wikipedia.