This year's No. 4 typhoon "Telly" is approaching step by step, and tomorrow (July 7) will make landfall on the coast of South China, becoming the first typhoon to make landfall in China this year. Affected by it, Hainan Island, Guangdong, Guangxi and other places will successively undertake strong wind and rain weather, local or extremely heavy rain, and there may be a highly destructive Taizian squall line. Where is the most likely landfall for "Terry"? How will the future affect our country? China Weather Network will interpret them for you one by one.
First, the intensity of Typhoon "Telly" has gradually increased, where is the maximum possible landfall?
Shi Yan, a meteorological analyst at China Weather Network, said that Typhoon "Teli" has the characteristics of stable westward direction and strengthening offshore strengthening. At 13 o'clock today, the center of Typhoon "Teli" (severe tropical storm) is located in the northeast of the South China Sea about 660 kilometers south-east of Zhanjiang City, Guangdong Province, China, it will turn northwest and northwest at a speed of about 15 kilometers per hour, gradually increasing in intensity, and make landfall along the coast from Taishan in Guangdong to Wenchang, Hainan on the night of the 17th.
"At present, 'Telly' is still developing slowly, and the typhoon cloud structure is gradually tightening, and the wind and rain on the south and west sides are strong. Due to the good SST conditions off the coast of South China, the next 24 hours is its golden development period, and its intensity may increase rapidly in the offshore waters, reaching the level of a typhoon to a strong typhoon. Shi Yan introduced that Typhoon "Teli" will become the first typhoon to land in China this year, and from the current weather situation, the most likely to make landfall on the night of the 17th is the Leizhou Peninsula in Guangdong.
Second, the core impact period is approaching, which places will encounter the strongest typhoons and rains?
At present, although the main body of Typhoon "Teli" is still in the South China Sea, the peripheral cloud system has begun to affect Hainan Island and the coast of Guangdong. This morning, Haikou and Wenchang in Hainan experienced heavy rainfall, of which Wenchang received 1.102 mm of rain in one hour; 5~10 gusts occurred on the coastal islands of Guangdong.
As can be seen from the flow field map of Typhoon Terly, the cyclone in the counterclockwise wind field is very obvious and not small. At the same time, due to the high offshore sea temperature and the continuous transportation of water vapor by the southwest monsoon, the strength of "Telly" will continue to strengthen.
As the typhoon approaches step by step, strong stormy weather in parts of southern China and the southern sea area of China has appeared and continued. From July 7 to 16, heavy rain or torrential rain is expected in parts of central and southern South China, southern Yunnan, and eastern and southern Jiangnan, including parts of southern Guangdong, southern Guangxi, Hainan Island and southeastern Yunnan. At the same time, there will be 19~8 gales in the northern part of the South China Sea, Qiongzhou Strait and Beibu Gulf, of which the wind in some waters in the northwest of the South China Sea can reach 10~11 and gusts of 14~15; There are 16~8 level winds in Hainan Island, the southern coast of Guangxi and the southern coast of Guangxi, and the coastal areas of southwestern Guangxi and northeast Hainan Island can reach 11~12.
"Today, the wind and rain on Hainan Island are gradually rising, and tomorrow the wind and rain in Hainan Island, southern Guangdong, southern Guangxi and other places will be significantly strengthened, and will gradually enter the core impact period of typhoons and rain." Shi Yan said that Shenzhen, Zhanjiang, Maoming, Yangjiang, Haikou, Qionghai, Wenchang, Fangchenggang and other places may have heavy rain to heavy rain, and even exceptionally heavy rain in local areas. In the above-mentioned areas, it is necessary to do a good job in the windproof reinforcement of construction sheds, outdoor billboards, street trees, etc., and pay attention to preventing various secondary disasters that may be caused by heavy rainfall. At present, it is the peak period of summer vacation tourism, and tourism projects such as islands and seas in the coastal areas of South China need to be well managed.
Third, when the strong convection on the coast of South China hits, why did the squall line appear before the typhoon?
In addition to creating strong wind and rain weather, "Telly" will also bring strong convective weather such as lightning, short-term heavy precipitation, thunderstorms and winds. "Guangdong and Hainan should be especially vigilant against the squall line, and the possibility of tornadoes cannot be ruled out." Shi Yan said that the "squall line in front of the typhoon" refers to the organized convective echoes that appear in the front of the typhoon's periphery, which is usually accompanied by intense strong convective weather and has strong destructive power. In the early stage, high temperatures prevailed in South China, accumulating sufficient energy, and before the typhoon made landfall, its peripheral circulation was very easy to stimulate strong convective weather, and even tornadoes!
So, why is there a squall line in front of the stage? Shi Yan explained that because the atmospheric energy gradually tends to be unstable before the arrival of the typhoon, it is easy to stimulate convective weather at this time, especially when the spiral cloud structure of the typhoon is close to the land, and the convective cloud belt around the typhoon is affected by the topographic uplift to enhance the convective activity. In the case of Guangdong Province, 40% of landfall typhoons will produce squall lines.
The squall line is a thunderstorm group arranged in a line (band), or it can be regarded as an "aircraft carrier" with strong convective weather, and each convective single thunderstorm is like a fighter on an "aircraft carrier". From the weather radar map, the squall line is like a sugar gourd, wearing a string of thunderstorms or cumulonimbus clouds.
The squall line is characterized by a smaller scale and a shorter life history. Generally, the ratio of length to width of the squall line is greater than 5:1, its width is 20 to 50 kilometers, and the length is generally from tens of kilometers to hundreds of kilometers. The squall line appears very suddenly, and its maintenance time varies from a few hours to a dozen hours. When the squall line crosses, the energy it carries is huge, the wind direction changes, the air pressure surges, the temperature drops sharply, and at the same time, the wind, hail, and sometimes even tornadoes appear, which can cause serious disasters.
Fourth, the intensity of "Terly" has weakened significantly after landing, how will it develop in the later period?
After Typhoon "Teli" makes landfall, the intensity will be significantly weakened, and on the 18th, "Taili" will hover in the Beibu Gulf, and then continue westward, and will also bring strong wind and rain to Guangxi and Yunnan. It is not expected that the wind and rain impact of "Telly" will gradually weaken until after the 19th.
As the first typhoon that will make landfall in China this year, the impact of Typhoon "Telly" should not be underestimated. China Weather Network reminds the public who live or need to travel to coastal areas in South China to pay close attention to typhoon trends, avoid entering typhoon-affected danger areas, and prepare for typhoon and wind protection in advance; If outside, never take shelter from the wind and rain near temporary buildings, billboards, towers, large trees, etc., and move indoors as soon as possible. (Planning/Du Bingbing Data Support/Shi Yan)