State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences
Using important weather reports from Chinese surface-based observing stations,the China Meteorological Administration (CMA) tropical cyclone best track data and hour-by-hour precipitation data from 2010 to 2016, statistical analysis of surface gales and its accompanying weather in southeastern China under the influence of tropical cyclones (TCs) was conducted, and the results show that: 1) TC gale in this region is mainly distributed along the coastline, with decreasing frequency from coast to inland; TC gale is dominated by the northeast wind direction, and the gale is mostly before the typhoon landfall. The strong wind speed of magnitude 12 and above are distributed within 300km of the TC center; 2) TCs of TS and TY intensity caused the most gale, but the strong wind speed of magnitude 16 and above are mainly found in the STY and Super TY intensity classes. Gale caused by slow TC mainly appears its shift to the right front side, and fast mainly appears its right rear side. The mean onshore wind speed of TC gale are slightly larger than the offshore wind speed, although the station frequency of onshore wind is more than that of offshore wind when the wind speed between level 12 and level 16,when the wind speed above level 16,offshore wind is much more than that of onshore wind ; 3) TC gale accompanied by precipitation accounts for about 89.8% of the total number of TC gale, distributed near the center of TC, with predominantly northeasterly winds and peak frequency occurring in August.TC gale without precipitation accounts for about 10.2%, mainly distributed in the periphery of the TC, with northerly and southeasterly winds predominantly with weak wind speed, mostly in May and December.TC gales with wind speed above level 12 are almost always accompanied by precipitation, while there are few samples of TC gales with wind speed above 12 without precipitation; 4) Accompanied by strong convective weather TC gale accounts for about 23.8% of the total TC gale, with northeasterly winds dominating, the average wind speed is greater than the non-strong convective TC gale; Strong convective weather including short-term heavy precipitation and thunderstorms, with the majority of short-term heavy precipitation (about 79.5% of this type of TC gale), mainly distributed in the northeast quadrant near the TC center, while thunderstorm TC gale mainly appears in the periphery of TC (about 28.0% of this type of TC gale), of which there are relatively few in the southeast quadrant. 5) TC gale with both short-time heavy precipitation and thunderstorms accounts for only 1.8% of the total TC gale and 7.5% of strong convective TC gale, indicating that thunderstorms were not common in TC gale with short-time heavy precipitation.