What level of typhoon will suspend classes?
Typhoon, also known as hurricane. It is a tropical cyclone formed on the vast sea surface with tropical or subtropical sea surface temperature above 26℃.
Meteorologically, according to the definition of the World Meteorological Organization, tropical cyclones with sustained wind speeds of 12 to 13 are called typhoons or hurricanes.
The life history of tropical cyclones can be divided into three stages: generation, maturity and extinction. Its average life span is about a week, the shortest is only 2-3 days, and the longest is about a month.
The generation and development of tropical cyclones need huge energy, so they are formed on the tropical ocean surface with suitable meteorological conditions such as high temperature and high humidity. According to statistics, tropical cyclones are generated in tropical oceans all over the world except the southeast Pacific Ocean.
It is usually formed on the sea surface 3-5 latitudes away from the equator in tropical areas, and its movement is mainly affected by large-scale weather systems, and eventually dissipates at sea, or degenerates into an extratropical cyclone, or dissipates after landing.
Tropical cyclones landing on land will bring serious property and casualties, which is a natural disaster. However, tropical cyclones are also part of the atmospheric circulation, which can bring the thermal energy and angular momentum of the earth's rotation from the equatorial region to a higher latitude.
reference data
Typhoon. China Weather Typhoon Network [reference time 2018-1-14]