Sever Weather in China

       Tornadoes can form in several ways; they can form on their own, or in conjunction with mid-latitude cyclones or in conjunction with hurricanes. A vertical sheer is the first step in a tornado development. The first object that forms is the rotating body of air at the ground. Wind speeds are higher as you increase in altitude. Vertical wind profiles sometimes cause updrafts to rotate which mesocyclones usually spawn Tornadoes. Horizontal rotating air is lifted off the ground by the updraft of the thunderstorm. Once the horizontal rotating air mass is lifted nearly vertically, it will be considered a mesocyclone. Tornadoes in the United States usually travel southwest to northeast.This is the dominant direction in the US because of prevailing winds. Tornadoes can happen in China, mostly on the east coast of China. China doesn't have as many tornado averages as does the US. China has about twenty to thirty tornadoes each year (Open Hazards). The average number of tornadoes observed in the US each year are 1253 tornadoes (NOAA).

      

This image is from http://www.ncdc.noaa.gov/climate-information/extreme-events/us-tornado-climatology.

       China doesn't really get many tornadoes, but the tornadoes that do happen occur in the east coast of China. Based on the annual US Annual Tornado count graph, tornado occurrences appear to have increased over time. But, it might not be fully true either. Tornadoes might have increased in the last 30 years possibly because of global warming. Since, the ocean waters are becoming more warm, it creates more strength in creating stronger weather conditions like hurricanes and thunderstorms. Also, tornadoes might have increased in the last 30 years because there have been many technological advances in the Meteorology department that can detect tornadoes in better ways. 

This image is from http://www.atmos.washington.edu/~hakim/101/hurricanes/. 

       The three main weather requirements that are needed to form a hurricane are warm ocean waters, unstable conditions, and moisture in the mid-troposphere. Hurricanes gain their power from the warm water because the warmer the water, the more energy can be extracted during condensation, and the stronger the storm can grow. Unstable air is typically very warm and moist air, so when lifted it will continue to rise on its own. The more unstable the air is, the more rapidly it will rise. Rapidly rising air helps to creates stronger thunderstorms which contribute to the overall hurricane. Also, hurricanes require a moist mid-troposphere to help keep their clouds and thunderstorms in tact. The typhoon season lasts from the early summer to early autumn around the China area and that means there are warm waters and unstable conditions during those seasons. In the Atlantic ocean, they are called hurricanes; in the Indian Ocean they are called cyclones and off the coast of China they are called typhoons. Hurricanes in the United States usually go through the east coast or middle east region of the country. They all travel from the gulf coast of Mexico or caribbean sea region. This is the dominant path of hurricanes because the gulf coast of Mexico and caribbean sea always has warm waters. Hurricanes do happen in China but they are known as Typhoons. There are an average of 7 typhoons each year (China). There is an average of 6 hurricanes that hit the US each year as calculated from the Hurricane Research Division in the Atlantic Oceanographic and Meteorological laboratory (AOML).