July 1 Weather in Shenzhen

The main features of the climate in Shenzhen in 2005 are "less rainfall before and after, more in the middle, low temperature in winter and spring, high temperature in summer and autumn, more disastrous weather and less typhoons". That is, the rainfall in1-April and1-kloc-0/2 is obviously less, the flood season is late, and the rainfall is more in May-September; The temperature is low in winter and spring and high in summer and autumn. The high temperatures in July, September and 10 all broke the record of the same period in history. There are many disasters: Cold New Year's Day, persistent fog, continuous drought in autumn, winter and spring, heavy rain, strong thunderstorm, gale and hail, high temperature, smog and other disasters appear alternately, but the impact of typhoon is weak.

Noun notes:

1, multi-year average-197 1 ~ 2000 statistical average.

2. Too much (less/high/low)-refers to the multi-year average compared with the same period.

3. Historical records —— Since records were recorded, meteorological records in Shenzhen have started from 1 July, 9521.

4. Heavy rain-the daily rainfall is 50 ~ 99.9 mm (mm).

5. Heavy rain-daily rainfall 100 ~ 249.9 mm (mm).

6. Extraordinary rainstorm-daily rainfall ≥250 mm (mm)

7. High temperature-daily maximum temperature ≥35℃

8. Low temperature-daily minimum temperature ≤5℃

9. Strong wind-gust wind speed ≥17.2m/s (m/s).

10, haze-air turbidity, relative humidity < 70%.

I. Basic climatic conditions

1, the precipitation is slightly normal, and the spatial and temporal distribution is uneven.

In 2005, the annual rainfall in Shenzhen was 2 143.6mm, which was 9% higher than the average over the years. Rainfall periods are unevenly distributed throughout the year, with about 60% more precipitation in May, June and August, the same precipitation in July and September, and less precipitation in other months. There is a clear distinction between dry season and rainy season. The precipitation in June 5438+10-April is only 1 12.6 mm, which is 64% less than the historical period (3 15.0 mm), resulting in a serious drought in the spring of 2004-2005. The flood season is postponed to May and August (the average flood season is April 18). The accumulated rainfall in the flood season (April-September) reached 2037.7mm, which was 23% more than the same period in history, and was 1.9 times of the rainfall in the flood season in 2004. It was also one of the 13 wet years in which the rainfall in the flood season exceeded 2000mm since Shenzhen recorded. However, after entering 10, the rainfall drops sharply, and the rainfall from 10 to 12 is 79% less. Annual precipitation days 127 days, less 17 days; The annual maximum daily rainfall is 240.0mm, which occurs on August 20th.

In 2005, 95% of the rainfall occurred in the flood season. From April to September, the rainfall distribution in the east is generally less. The accumulated rainfall in the eastern part of Longgang District exceeds 2,000mm, the rainfall in Xia Ling, Bagang and Kwai Chung exceeds 2,400mm, and the rainfall in the northern part of Baoan District and the southern part of Nanshan District is insufficient1.500mm.

2. The average temperature is on the high side, and the change of hot and cold is significant.

In 2005, the annual average temperature in Shenzhen was 23.2℃, which was 0.7℃ higher than the average temperature for many years. This is the 20th year of continuous warming since 1986, but the average temperature in 2005 was relatively low since 1997. The annual average maximum temperature is basically the same as the historical average maximum temperature; The annual average minimum temperature is 265,438 0.0℃, which is 65,438 0.4℃ higher than the average temperature over the years. The annual extreme maximum temperature of 37.3℃ appeared on July 19, the third highest in history. The high temperature (≥35℃) lasted for 6 days, in which 10 had high temperatures of 35.6℃ and 35.2℃ on September 22nd and June 2nd, respectively, which broke the record of the same period in history and was the latest high temperature weather since meteorological records were recorded. The extreme minimum temperature in the whole year is 3.4℃, which appears in June at 65438+1 October1,making it the coldest New Year's Day in recent 30 years.

3. The sunshine is seriously less, which is a historical record.

In 2005, the sunshine hours in Shenzhen were only 1574.3 hours, which was 359.5 hours less than the average for many years and the lowest in history. Among them, the first quarter and the second quarter are obviously less, less than 126.0 and 150.7 hours respectively. The main reason for the serious shortage of sunshine hours is that there were three cold and rainy weather processes in our city in the first quarter, and rare fog appeared for three consecutive days on February 23-25. After entering the rainy season, the frequent continuous rainfall in our city is also a major reason for the lack of sunshine. From April to September, there were 36 days without sunshine.

4. The relative humidity is extremely low, hitting a record low.

In 2005, the average relative humidity in Shenzhen was only 70%, which set a new record for the driest year in history last year. Only February is slightly higher than the historical period 1%, and the average relative humidity in other months is obviously lower than the historical period (Figure 6). Among them, the minimum relative humidity recorded by the Municipal Meteorological Observatory on June 7 and February 22 was 1 1%, which broke the lowest record in the same period in history.

Two. Major meteorological disasters and major weather events

The meteorological disasters that have obvious influence on Shenzhen in 2005 are: drought from April 2004 to April 2005, continuous fog in February, disastrous rainstorm in May 19, continuous rainstorm in June 2 1-24, heavy rainstorm on August 20, Xiaolongjuan on May 9, April 25, June 22 and July 20. 18 sustained high temperature on July 20th, 10 abnormal high temperature in autumn on September 22nd, etc. There are six tropical cyclones affecting our city, but there is no direct impact. According to incomplete statistics, 8 people died directly this year due to meteorological disasters or derivative disasters (strong winds, lightning strikes, landslides, etc.). ).

1, drought

Although the annual rainfall in 2005 was higher than the average level in previous years, the temporal and spatial distribution of rainfall was extremely uneven. Among them, the cumulative rainfall in June 5438+0-April was 64% less than that in the same period in history. Since April 2004, the rainfall in 13 months is less, which makes the drought more serious, which is the worst drought year in 52 years after 1963. The rainfall in the fourth quarter was 36.2 mm, 78.8% less than that in the same period of normal years, and there was moderate drought in autumn and winter.

In order to solve the persistent severe drought, from March 13 to early May, our city launched the "Rain Enhancement and Drought Relief" campaign, flying1/KLOC-0 for about 25 hours, and sowing 176 particles of flue pipe catalyst. Fig. 6 is a flight path diagram of aircraft operation. According to the average precipitation enhancement efficiency 10%- 15% calculated by authoritative departments, the city has increased water storage19.5 million cubic meters, at the same time, the soil moisture has been effectively improved and the air has been purified, which has played a positive role in protecting and improving the ecological environment of our city.

2. Heavy fog

There have been four days of foggy weather in Shenzhen this year, the most in 10 years. Among them, rare fog appeared for three consecutive days from February 23 to 25, and the lowest visibility was only 100 meter, which was the lowest and longest foggy weather process in history and the second time in the 53-year historical record of our city. The foggy weather caused nearly 200 flights in our city to be delayed, of which 16 flights were cancelled, the Meiguan Expressway was once closed, and the number of traffic accidents soared, resulting in the death of 1 1.

3. Heavy rain

After entering the flood season in 2005, local heavy rainfall, persistent heavy rain and extremely heavy rain frequently occurred in our city, and the number of rainstorm days in the whole year reached 13, which was the fourth highest since records began. The Municipal Meteorological Observatory issued rainstorm signals for many times, and the first black rainstorm signal was issued on August 20th, 2005, when the daily rainfall was the largest.

19 On the morning of May 6-8, the cumulative rainfall in Nanshan Station reached 177mm, and the hourly rainfall reached 60.7mm on the morning of March 3-4. On the morning of July 7-8, heavy rainfall occurred again, with an hourly rainfall of 44.1mm. Short-term heavy rainfall and the influence of topography have caused serious water accumulation on the southern road and traffic jams, with the deepest water accumulation reaching 2 meters. Due to the traffic jam, some passengers can't arrive at the airport in time, which leads to the delay of the departure time of 18 flight, and also causes problems such as students who arrive at school being trapped by stagnant water, the collapse of walls, and the failure of signal lights.

On June 2 1-24, the accumulated rainfall of the Municipal Meteorological Observatory reached 204.9 mm, and there was a torrential rain exceeding 100 mm in Dapeng Peninsula in eastern Shenzhen for three consecutive days, and the accumulated rainfall in South Australia reached 557 mm for four days. On the 23rd, flights were delayed due to weather. On the 24th, the Beijing-Kowloon Railway was in many dangerous situations, involving five trains originating or arriving in Shenzhen. The slope of Anlijia Factory in Baolai Industrial Zone, Pinghu, Longgang collapsed, and a small number of riverbanks of the Pinus tabulaeformis River in Futian and Longhua collapsed, resulting in landslides at the junction of Shenhui, resulting in four deaths and four injuries in Nankeng Village, Xinxu Town, Huiyang.

On 20 August 19-20, a rare rainstorm process was triggered by intertropical convergence zone and weak cold air. On the 20th, the daily rainfall recorded by five automatic weather stations in the city exceeded 250 mm, of which the maximum daily rainfall in Longhua was 304 mm, and the rainfall in Longhua 1 hour was as high as 7 1 mm at 9- 10. Continuous heavy rainfall caused landslides, lightning strikes, floods and other disasters in our city, resulting in five deaths and direct economic losses of 65.438+0.8 billion yuan.

4. Tornadoes and hail

On May 9, July 15 and July 22 this year, there were three small-scale tornadoes in Baoan Shajing, Xiasha Village in Futian District and Futian Free Trade Zone respectively. Among them, the tornadoes near Baoan Shajing Third Industrial Zone and Guanlan Dashuikeng Waste Acquisition Station appeared obvious disasters on May 9, and the tornado lasted about 25 minutes. Shops on the south side of the reservoir market in the third industrial zone of Shajing were destroyed, tricycles were vacated and iron houses were lifted; The waste collection station in Guanlan Dashuikeng was ransacked, and the iron frame was fragmented and debris was flying all over the sky. The destruction time was about 2-3 minutes.

On April 25th, influenced by the trough of low pressure and low-altitude shear, a strong thunderstorm cloud moved from the Pearl River Estuary to Gongming Fuyong area in Baoan, and continued to move westward. There are obvious hailstorms in Gong Ming, Fuyong, Pinghu and other places in our city, which last for about 2-3 minutes and are as big as soybeans.

5. Thunderstorm

Although the number of thunderstorm days in our city in 2005 was slightly less than that in previous years, the intensity was extremely strong, and strong thunderstorms were accompanied by strong winds, hail and other strong convective weather.

June-Thunderstorms are the most frequent: In June this year, there were four thunderstorms and windy weather in our city. The strongest intensity was at 12 night, and Longgang recorded a short-term thunderstorm and gale of 26 m/s; The largest range was around 9: 00 a.m. on the 22nd, gusts of magnitude 8 or above were recorded in Shekou, Nanshan and Luohu, among which the largest gusts in Shekou reached 10(24.8 m sec), Nanshan 9(2 1.8 m sec) and Luohu 8( 19.2 m sec).

July-the strongest thunderstorm: On the night of July 20th, the strongest thunderstorm and windy weather in 2005 occurred in our city, and the number of lightning strikes in Shenzhen reached 94 1 time; Several automatic stations recorded short-term gale of 8- 1 1, among which Dapeng station recorded gale of 29.0 m/s; The rainfall intensity is relatively high in some areas, and the rainfall at Bagang Station 2 1-22 reaches 70 mm/h.

August-Maximum thunderstorm range: On August 13, the biggest thunderstorm gale process occurred in our city since 2005. On June 3rd 16:20- 18:00, a thunderstorm and gale occurred in the whole city. The number of cloud-to-ground lightning in our city is as high as 1 197. Fuyong Station recorded an instantaneous 10-level thunderstorm and gale with a maximum of 28.2m/s, and this station also recorded 22.9m..

6. High temperature

During the year, the Municipal Meteorological Observatory * * * recorded six days of high temperature weather above 35℃, which appeared on July/KOOC-0/8-20, August/KOOC-0/2, September 22 and June/KOOC-0/0 respectively, and there were cases of heatstroke/KOOC-0/0 throughout the year.

In the middle and late July, influenced by the subtropical high and the downward flow around Typhoon Haitang, there were eleven consecutive days of hot and humid weather in 1 1-2 1, in which 18-20 exceeded 35℃ for three consecutive days, and the highest temperature reached 19. Due to the influence of hot and humid weather for several days, many people died of heatstroke in Shenzhen, coupled with upper respiratory tract infection, gastrointestinal tract infection and the peak of pediatric patients, electricity consumption was overloaded, and power supply cables in some areas were burned, resulting in a large-scale power outage.

On September 22nd, affected by subtropical high and typhoon "Davi" heading south, the city generally experienced high temperature above 35℃, and the highest temperature recorded by the Municipal Meteorological Observatory was 35.6℃, which broke the highest record in the same period in late September (34.7℃) and was the only high temperature in the city in late September.

6543810.2, affected by typhoon "Dragon King" and downdraft, the city experienced high temperature in autumn again, with the temperature reaching 35.2℃, which set a new record for the latest high temperature in the season on September 22.

7. Tropical cyclones

There are no tropical cyclones that directly affect our city this year, but there are six tropical cyclones that indirectly affect our city, namely Haitang No.5, Tianying No.8, Mai Sha No.9, Coral 10, Vicente 16 and David 18.

"Begonia", "Eagle", "Mai Sha", "Coral" and "David" brought high temperature and stormy weather to our city. Among them, influenced by "Haitang", the highest temperature in our city in 2005 was 37.3 degrees. Three and a half days later, Typhoon 05 18, which slowly crossed the northern part of the South China Sea and landed in Hainan, was the most serious typhoon that affected our city this year, bringing high temperature, smog, strong wind and heavy rain to our city successively. On September 22, the high temperature above 35℃ generally appeared in the city; On 2 1-22, there was severe smog weather, and the visibility dropped to 2.5 kilometers; "David" crossed the South China Sea about 300 kilometers away from our city from day to night on the 24th. On 24th-26th, there was windy weather in our city for three consecutive days, with land winds of 5-6, gusts of 8-9, coastal winds of 7-8, and gusts of 10 or above. On the afternoon of 24th, Shekou Station and Qi Long Station recorded 35. 1 and 33.6 respectively. From 25th to 26th, there was heavy rain to rainstorm in our city.

8. Strong wind

In September, due to the influence of tropical storm Vicente and subtropical high, windy weather occurred in our city for two consecutive days in 17 and 18. The average wind force on land is 5-6, the average wind force on the coast is 5-7, and the gust is 1 1. More than a dozen automatic weather stations in the city recorded strong winds above 17m/s, among which the instantaneous wind speed in Shekou and Qi Long reached 1 1(28-30m/s), and the strong winds of 17m/s also appeared at this station 17. The Municipal Meteorological Observatory issued the first strong wind warning.

9. Cold

Although the annual average temperature was high in 2005, the staged cold weather was obvious. In * * *, there were 23 cold days when the minimum temperature was lower than 10℃, and the extreme minimum temperature was 3.4℃, which appeared at 65438+ 10/day, making it the coldest New Year's Day in recent 30 years. In mid-March, affected by strong cold air, the temperature in our city plummeted. From 05: 00 on March 12 to 05: 24 on March 13, the temperature drop reached 15.3℃, which is rare in history. /kloc-The average daily temperature in March is only 8.5℃, which is the lowest in mid-March. In one year, the number of poisoning cases caused by the use of gas in cold weather was as high as 17 18.

10, haze

In 2005, the number of smog days in our city was 135 days, which was 42 days less than that in 2004, but it still ranked second in history. The haze days in the fourth quarter and the first quarter were 6 1 day and 37 days respectively. Affected by the subtropical high and the descending airflow around Typhoon Haitang, severe haze weather occurred for three consecutive days from June 19 to July 2 1 day, with a minimum visibility of about 3 kilometers. Affected by Typhoon David, severe smog weather occurred on September 2 1-22, and the visibility dropped to 2.5 kilometers ... The appearance of smog led to a serious decline in air quality. On February 26th, 65438, the air pollution index in Nanshan Station reached 143, which was mild pollution.