China News Agency, Beijing, November 10 (Reporter Chen Hang) The reporter learned from the Beijing Meteorological Department on the 10th that Beijing officially entered winter on November 3, which is 3 days later than the normal (1991-2020 average) winter time. .
Affected by the strong cold air, from the 11th to the 13th, Beijing will welcome the first rainfall and strong wind cooling process since the beginning of winter this year.
The Chinese meteorological industry standard - "Climate Seasonal Division" stipulates that the 5-day sliding average temperature is calculated based on the current year's temperature sequence to form a sliding average temperature sequence. When the sliding average temperature sequence is less than 10°C for 5 consecutive days, the corresponding current year's temperature sequence The first date less than 10°C is regarded as the starting date of winter. If the starting date of the initial judgment is more than 15 days earlier than normal, a second judgment of the starting date is required.
According to the meteorological department, according to the actual calculation of temperature in Beijing since October 20, the sliding average temperature sequence has been less than 10°C for 5 consecutive days since November 5th, and the corresponding daily average temperature sequence is the first date less than 10°C. It is November 3 (9.1 ℃), which is slightly later than the annual winter entry date (October 31), so there is no need to make a second judgment. Based on this, it can be judged that the winter entry date this year is November 3.
The meteorological department said that due to the weak air pressure field, the atmospheric diffusion conditions in Beijing deteriorated. Light fog appeared on the morning of the 10th, and the fog dissipated in the morning, and the visibility slowly recovered.
Du Jia, chief forecaster of the Beijing Meteorological Observatory, said that due to the strong cold air, from the 11th to the 13th, Beijing will welcome the first rainfall and strong winds to cool down the weather for the first time since the beginning of this winter.
The accumulated rainfall in this precipitation process was large, and there was strong wind after the rain, the wind chill effect was obvious, the temperature dropped greatly, and the visibility was low.
The meteorological department said that this cold air process has caused a significant drop in temperature. It is necessary to guard against colds and cardiovascular and cerebrovascular diseases. When going out, pay attention to adding clothes to keep warm, windproof and cold.
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