Kanu may enter the Northeast tonight! Why has the typhoon had such a significant impact on the north this year | Typhoon | Northeast region

According to the warning from the Central Meteorological Observatory, Typhoon Kanu, the 6th typhoon of this year, is expected to enter the northeast region of China on Friday night.

Previously, due to the northward circulation of Typhoon Dussuri, heavy rainfall processes occurred in Beijing, Tianjin, Hebei and other areas, exhibiting characteristics such as long duration and large cumulative rainfall.

And Typhoon No. 7, "Lan En," is also on the verge of action. It upgraded to a severe tropical storm on the morning of the 9th and will move in the direction of "Kanu," possibly affecting the northeast region of China.

Why did this year's typhoon have such a significant impact on the north from Hebei to Northeast China?

Quantity decreases, strong winds increase

According to the Tropical Cyclone Data Center of the China Meteorological Administration, as of August 9th, a total of 7 tropical cyclones, including 7 typhoons, have formed in the northwest Pacific Ocean this year.

This number is the lowest since the same period in nearly 12 years and far below the average level of about 14 typhoons since 1949.

But in terms of intensity, this year there have been many super typhoons, making it an elite special forces force.

After all, only one "Du Suri" has brought strong storms to more than ten provinces in China.

According to China Weather Network, "Du Suri" is also the second strongest typhoon to make landfall in Fujian Province since complete observation records began. At the time of landfall, the maximum wind force near the center reached 15 levels.

What concept is it?

Equivalent to a small car running at a speed of 200 kilometers per hour, it can cut off and uproot large trees.

According to the national standard of Tropical Cyclone Classification, typhoons can be divided into 6 levels based on average wind speed. Level 1 is the weakest and is a tropical depression, while level 6 is the strongest and is called a "super typhoon".

Among the previous 6 typhoons, 3 reached level 6 in intensity. From the current perspective, both the quantity and proportion are extremely high.

Because in the past 70 years, the average number of "super typhoons" in China each year has only been 3, accounting for 13%.

And typhoons usually occur from May to October every year, and it is not yet mid August. It is unknown whether there will be more "super typhoons" in the future.

This year, the number of typhoons is relatively small and the intensity is relatively strong, which is related to El Ni ñ o.

Due to the increase in sea surface temperature in the eastern equatorial Pacific and the lower sea surface temperature in the tropical western Pacific, the heat and water vapor provided to the atmosphere in the northwest Pacific decrease, and the convective activity in low latitude areas of the Pacific weakens, which is not conducive to the circulation conditions required to form typhoons, resulting in less typhoon activity.

Meanwhile, due to its production location leaning towards the south and east, its strength is relatively strong.

From a data perspective, the same applies.

During the three El Ni ñ o periods of 1982-1983, 1997-1998, and 2014-2016, the number of typhoons occurred was lower compared to the overall period of 1949-2022 and non El Ni ñ o years. However, the average number of occurrences of typhoons with a strength level of 6 is higher than in previous years.

Typhoon passing through Northeast China is not uncommon

In the public's impression, the eastern and southern coasts of China are the hardest hit areas for typhoons to enter, and it is unlikely that there will be typhoons in the north.

But in fact, the impact of typhoons in previous years was not limited to the south.

The inland areas of our country, such as Guizhou, Sichuan, Shaanxi, etc., have all been hit by typhoons.

For example, the super typhoon Wendai in 1956 caused 17000 injuries and 2.2 million houses to be damaged. It made landfall in Zhejiang and went deep inland, passing through provinces such as Henan, Shanxi, and Shaanxi before finally disappearing at the border between Shaanxi and Inner Mongolia.

The reason why the public believes that typhoons are limited to the southern coastal areas is that as they penetrate deeper into the mainland, their intensity gradually weakens, often less than 1, resulting in less impact.

The occurrence of typhoons in the Northeast region is not a rare occurrence in a century.

According to statistics, between 1949 and 2022, at least 30 typhoons arrived in Northeast China, with an average of one typhoon every two years.

Moreover, in recent years, the frequency of typhoons in Northeast China seems to have increased, with three typhoons in 2020 alone.

For example, the super typhoon Haishen in 2020 brought heavy rainfall as it passed through Jilin and Heilongjiang provinces. Suifenhe City in Heilongjiang Province recorded 156 millimeters of rainfall that year, breaking the historical record for this station. Heavy rainstorm also led to 23 rivers in the northeast of China to have floods above the warning level.

Precipitation and temperature are affected

Although the passage of typhoons through the north is not an exception, the rainfall in the north this year is particularly abnormal compared to previous years.

According to the China Climate Bulletin, over 60% of precipitation in the Beijing Tianjin Hebei region has been concentrated in July and August in the past three years. Beijing is the most special, with precipitation in July and August 2022 accounting for 80% of the annual precipitation.

But this year, precipitation in many northern regions has reached historical peaks. For example, Beijing experienced the largest rainfall in 140 years.

The average annual rainfall in Beijing is around 600 millimeters, and more than a year's worth of rainfall has been recorded in just three days this year.

According to statistics, from 20:00 on July 29th to 7:00 on August 2nd, the rainfall at Wangjiayuan Reservoir in Changping, Beijing reached 744.8 millimeters, surpassing the historical rainfall record in the Beijing area and becoming the highest recorded rainfall in 140 years with instruments.

And the impact of typhoons on the south is an exceptionally cool summer.

Taking Shanghai as an example.

Generally speaking, the temperature in Shanghai is higher in late July, with an average temperature of 2.87 degrees Celsius higher than in early July. But this year, due to the impact of typhoons, the average temperature in late July was only 31.48 degrees Celsius, a decrease of 2.48 degrees from the previous period.

This is similar to 2021.

At that time, Typhoon "Fireworks" moved slowly and occupied the eastern coastal areas of China for a long time. It not only dispersed the subtropical high pressure, but also provided abundant water vapor. The exclusion of the subtropical high-pressure belt, coupled with the cooling of rainwater, resulted in an overall low temperature in the latter half of the year.

So, will there be another typhoon in August?

Jia Xiaolong, Deputy Director of the National Climate Center, said that it is expected that there will be 4 to 6 tropical cyclones in the northwest Pacific and South China Sea in August, of which 2 to 3 will make landfall or significantly affect China, especially in the coastal areas of East and South China.