The rainstorm was sent to the Yangtze Huaihe River from a remote place?, Four Questions about Typhoon "Tai Li": "Fighting Bulls Across the Mountains" in Jiangsu | Rainfall | Typhoon
From July 16th to 17th, as Typhoon Tai Li, the fourth typhoon of this year, gradually strengthened towards the southern coast of China, another strong rainfall related to Tai Li occurred in Jiangsu, Anhui, Zhejiang and other places thousands of kilometers away. How did this rainfall occur? What other areas should not be taken lightly while preventing the main body of typhoon rainfall?
The reporter interviewed Wu Haiying, the chief forecaster of the Jiangsu Provincial Meteorological Observatory, for scientific answers.
Question: Thousands of miles away from Typhoon Tai Li, is there significant rainfall in Jiangsu, Anhui, and Zhejiang?
On July 17th, as Typhoon Tali approached, the wind and rain weather in southern China intensified. At the same time, in addition to the impact of the typhoon itself on southern China, some areas of Jiangsu, thousands of miles away, also experienced significant rainfall due to the typhoon's impact.
How strong is this rain?
Wu Haiying introduced that from 8:00 on July 16th to 3:00 on July 17th, a strong rain band appeared in the Jianghuai region along the Yangtze River in Jiangsu. Nanjing, Zhenjiang, Yangzhou, the central and northern parts of Taizhou, and the southern part of Yancheng are located on this rain belt. The rainfall in these areas exceeds 50 millimeters, with some areas exceeding 100 millimeters.
Even more extreme is that from last night to this morning, some of the above-mentioned areas showed very strong hourly rainfall. Among them:
Yangzhou Puxi Town experienced a sharp drop of 128.5 millimeters in 1 hour; The cumulative rainfall is also astonishing. From 8:00 yesterday to 3:00 today, the town has dropped a total of 302.4 millimeters.
In neighboring Anhui, from 2:00 to 14:00 on the 17th, the rainfall was also not weak. There were a total of 93 rainfall stations in the province with precipitation exceeding 50 millimeters, 23 rainfall stations with precipitation exceeding 100 millimeters, and the maximum in Hexian Xiangquan reached 162.0 millimeters.
So the question is, how did "Taili" affect the Jianghuai region thousands of miles away?
Question 2: How does "Tai Li" in the South China Sea "fight cows across the mountains"?
According to several experts, including Wu Haiying, although Typhoon Tai Li, located in the South China Sea, will not directly affect areas such as Jiangsu, Anhui, and Zhejiang, its formation of a "typhoon trough" is like "hitting cows across mountains", bringing heavy rainfall to areas thousands of miles away.
Wu Haiying introduced that unlike the main body concentrated near the center of the typhoon, the peripheral wind field of the typhoon generally extends over a wide range. Within the range of typhoon vortices, mesoscale shear lines often appear on the north, southwest, and southeast sides of typhoons. On the north side, there are shear lines caused by the southeast and northeast winds of typhoon circulation, known as typhoon troughs.
This time, "Taili" extends relatively far, and the groove happens to "buckle" in the Jiangsu, Anhui, and Zhejiang regions. The abundant water vapor in the region, combined with favorable uplift conditions, resulted in a "Tai Li" and "Da Niu" heavy rainfall.
Three questions: Besides "hitting cows across mountains", can typhoons also "knock mountains and shake tigers"?
The answer is yes.
Wu Haiying introduced that the peripheral wind field of the typhoon extends in different lengths. Stretching long, one can "fight cows across the mountains"; Stretching short can also shake the mountain and tiger.
In 2012, Typhoon "Haikui" made landfall and entered southern Anhui. From August 10th to 11th, as the "Haikui" weakened into a low-pressure circulation and the surrounding precipitation significantly weakened, its trough extended to northern Jiangsu and combined with cold air, causing nearly 500 millimeters of rain to fall in Xiangshui County, Yancheng City, northern Jiangsu Province in one day. Its impact cannot be underestimated.
Question 4: Beyond the main body of a typhoon, can the defense measures be relaxed?
"In terms of the impact of typhoon wind and rain, it is generally in the area of the typhoon body, with concentrated precipitation and a large range." However, Wu Haiying reminds that the impact of peripheral circulation such as typhoon trough should not be underestimated.
"When a typhoon reverses and combines with cold air, precipitation develops stronger and convection becomes stronger." Wu Haiying said that before and during the impact of a typhoon, combined with local weather forecasts, even if it is not within the main area of the typhoon, it is necessary to tighten prevention measures and be prepared to minimize the impact of disasters.