Who can put an end to the rare high temperature? Only cold waves and strong cold air!

The previous article "The higher you climb, the harder you fall - Talking about the most important points about the weather during the National Day holiday" interpreted the weather during this year's National Day holiday. Now that three days have passed, this article will use the four keywords "sensible heat, latent heat, exceptional and routine" as a guide to inform everyone of the actual weather conditions that have occurred and the latest forecast prospects, with the main focus on temperature.

1. Sensible heat: hot weather is developing in the south

Since September 29, the high temperature range in the south has been expanding day by day, and the temperature values ​​have been rising day by day. As of yesterday, the area with high temperatures above 35°C has been from Guangdong and Guangxi in the south to Henan in the north, the two lakes in the west, and Jiangsu and Zhejiang in the east. Most of the areas are above 37°C.

Actual maximum temperature from 08:00 on September 29 to 12:00 on October 2

According to data from the Meteorological Observation Center, among the total 2,431 national ground meteorological observation stations, 433 stations recorded maximum temperatures exceeding 35°C on October 1, of which 86 stations exceeded 38°C, and the Shitai station in Anhui reached 40°C. The high temperature areas were mainly concentrated in the northern and southern provinces of the middle and lower reaches of the Yangtze River.

II. Hidden heat: Extreme abnormal warmth coexisting in the north and south

The heat is obvious, but whether it is abnormal is more hidden, and it is necessary to check historical records. This investigation revealed that the heat in the south is very obvious, while the heat in the north is also hidden.

In the past three days, a total of 499 national stations in the south and the north have broken the highest temperature records for the same period in history! (Note: There are many ways to compare the same period in history, such as the same ten-day period and the same month. Because the past three days spanned a ten-day period, the comparison here is the strict historical period, that is, September 29 to October 1)

Actual highest temperatures across the country from September 29 to October 1

(Central Meteorological Observatory, red circles represent breaking historical extreme values ​​for the same period)

If you select two representative stations from the north and south to look at the record list, you will see more information than the record itself.

Beijing Railway Station

Beijing's record-breaking performance was not obvious, it just tied the record, but it was in the top 10 list for two days.

Hohhot, Inner Mongolia

Hohhot broke a small record and has been among the top 5 in history for the past three days.

Hubei Ezhou

Ezhou broke the record significantly. The temperature on October 1 was 3.7℃ higher than the previous record of 35.8℃ on September 30, 2019, and it broke the record for two consecutive days.

Anhui Shitai

Shitai in Anhui also broke the record twice in a row, with a significant drop of 3.2℃.

In summary, the temperature in recent days is abnormally warmer than the same period of previous years, so abnormal that it breaks the record, so it can naturally be called an extreme abnormality.

Temperature anomalies from 08:00 on September 22 to 08:00 on October 2 (red is warmer and blue is colder than normal)

It is not easy to explain the reason for such abnormal warmth. But we can briefly explain the direct cause of the high temperature in the south: the strong subtropical high pressure that is rare in this season controls most of the south.

500hPa isobaric surface contour lines at 08:00 on October 2, 2022 (the red bold indicates 588 potential decimeters)

3. Breaking the rules - Cold wave warning in an abnormally warm environment

Then, against this abnormally warm background, strong cold air is coming!

Sea level pressure at 08:00 on October 2, 2022

The 1040 hPa cold high pressure center and the huge cold high pressure body are rare in early October; this is a strong cold air, which will move eastward and southward in the next 5 days and sweep across most parts of central and eastern my country, which is also rare in this season.

When strong cold air meets an extremely warm previous background, the extent of the temperature drop can be imagined.

Taking into account the unusually warm weather in the early stage, the huge temperature drop and the fact that it happened during the long holiday, the Central Meteorological Observatory issued a blue warning for cold waves this morning. This is extremely unusual!

One unusual thing: This warning does not strictly meet the standards for cold wave warnings. One condition is not met, that is, the lowest temperature in the middle and lower reaches of the Yangtze River reaches 4℃, which means it is not "cold" enough. But except for this one, other indicators can be said to be far exceeded. Considering the comprehensive intensity and possible high impact, we still issued a warning.

The issuance of this warning can be said to be both exceptional and compliant: exceptional in that the indicators were slightly insufficient, and compliant in that the warning issuance specifications specifically provide for the situation where such indicators are insufficient and that it can be issued at its discretion.

The Central Meteorological Observatory issued a cold wave warning and temperature drop forecast at 10:00 on October 2

The Central Meteorological Observatory issued a cold wave warning at 10:00 on October 2, and the lowest temperature forecast after the temperature drops

The second unusual thing is that this is the earliest cold wave warning issued by the Central Meteorological Observatory in the second half of the year since the current warning measures were implemented in 2010.

The third unusual thing: The cold wave warning and high temperature warning were issued on the same day, which should be unprecedented!

The Central Meteorological Observatory issued a high temperature warning at 06:00 on October 2

Since the high temperature area in the south will not end until the cold air completely passes the Yangtze River on the 5th, the situation of issuing high temperature and cold wave warnings at the same time will continue in the next few days.

IV. Conventional - Pay attention to wind and rain

We have already witnessed the hottest summer in history in 2022, and we have continued to witness rare meteorological events in recent days. It is clear that the extremes and uncertainties of future weather and climate have become visibly complex, and perhaps more history will be witnessed in the near future.

But at the moment, we should also pay attention to the more normal weather. The wind and rain brought by this cold front are not abnormal in intensity.

In the area where cold and warm weather meet, Shaanxi, Gansu, Sichuan, Chongqing, Shanxi, Hebei, Shandong, Henan, Hunan, Hubei, Jiangsu, Anhui and other places will have rainfall from north to south in the next three days. The rainfall will not be very heavy. Most areas will have moderate to heavy rain, and there will be rainstorms in some areas. Some warmer areas on the south side of the rain belt will also be accompanied by strong convective weather. The following are some precipitation forecast maps from the Central Meteorological Observatory for reference. Please refer to the latest forecasts in various places:

The strong winds brought by the cold front are generally not strong. There are 4-6 northerly winds in the north of the Yangtze River, 7-8 gusts in plateau and mountainous areas and rivers and lakes, and 5-7 gusts in rivers and lakes in the south of the Yangtze River. The strongest winds are in the eastern sea area, with 7-8 gusts and 9-10 gusts. Such winds pose the greatest threat to activities on the water, so please take precautions.

Finally, I would like to fill in the gap in the previous article about the later attention paid to Typhoon Olu. At present, it seems that Olu has not come back from the dead, and there is no chance for it to land on the Indian Peninsula after coming back from the dead. This is very interesting, because the low-pressure circulation is very clear, and the convective clouds around it are also very active, but it has not gathered into a typhoon - I guessed the beginning, but not the ending.

Sea level pressure at 11:00 on October 2, 2022 and Fengyun-4A visible light cloud map at 12:00

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