What’s so special about weather events that have “numbered identities”?

Numbering is one of the ways to mark and identify weather events. What is so special about numbered weather events? How are they treated differently after getting a "numbered identity"? This issue takes you through a list of weather events with "numbered identities".

【Typhoon】 Numbering has a long history and international organizations have unified naming

At present, the weather events that are numbered in my country include typhoons, northeastern cold vortexes, and cold waves. Take the typhoon, a very destructive weather system, for example. On average, about 7.2 typhoons land in my country every year. The meteorological department needs to closely monitor the typhoon's movements and issue forecasts and warnings in a timely manner. However, some typhoons have a long life span and a wide range of influence. Sometimes two or more typhoons will "dance" on the sea surface, and some typhoons will even "revive". In order to facilitate monitoring and management, it is particularly necessary to number the typhoons.

Typhoon No. 9 "Sura" and Typhoon No. 11 "Haikui" in 2023 monitored by Fengyun-4A Source: National Satellite Meteorological Center As the "big brother" of numbered weather events, the numbering of typhoons can be traced back more than 60 years ago. Since 1959, China has numbered tropical cyclones (tropical storm level and above) with near-center maximum wind speeds greater than or equal to level 8 that occur or enter the northwest Pacific and South China Sea north of the equator and west of 140° east longitude in the order of their appearance. Since the late 1970s, the numbering range has been expanded to the west of 150° east longitude. Currently, the numbering range has been expanded to the west of 180° east longitude. In order to avoid confusion in usage, in 1980, the 13th session of the Typhoon Committee of the World Meteorological Organization/Economic and Social Council for Asia and the Pacific (WMO/ESCAP) decided to entrust the regional professional meteorological center, the Tokyo Typhoon Center, to uniformly number tropical cyclones that appear on the northwest Pacific and South China Sea west of longitude 180° and north of the equator with a maximum average wind speed of more than 17.2 m/s near the center and an average wind force of more than level 8.

Source: Central Meteorological Observatory

Unlike the northeastern cold vortex and cold waves, which are numbered with numbers, tropical cyclones will have their own "names" once they develop into typhoons. In 1998, the 31st session of the Typhoon Committee of the World Meteorological Organization/Economic and Social Commission for Asia and the Pacific (WMO/ESCAP) approved the naming scheme for tropical cyclones in the Northwest Pacific and the South China Sea, and entrusted the regional professional meteorological center-Tokyo Typhoon Center to be responsible for the daily naming. As the only numbered weather event managed by an international organization, the numbering of typhoons involves many countries (regions). There are 140 names in the Typhoon Committee's naming table, which are provided by Cambodia, China, North Korea, Hong Kong, Japan, Laos, Macau, Malaysia, Federated States of Micronesia, the Philippines, South Korea, Thailand, the United States and Vietnam in the Asia-Pacific region. After consultation, the Central Meteorological Observatory, the Hong Kong Observatory, and the Macau Geophysical and Meteorological Observatory determined a unified set of Chinese names. Since then, typhoons have begun to have "Chinese names".

[Northeast Cold Vortex] has significant regional characteristics and can affect central and eastern China

The Northeast Cold Vortex - "a cyclonic cold vortex of weather scale in the middle and upper troposphere active in and near Northeast my country" is the most distinctive weather system in the Northeast region and an important weather system in the Northeast Asian atmospheric circulation. It is an important influencing system that causes large-scale rainstorms, heavy snow, severe convection and other disastrous weather events in Northeast China and even in the central and eastern regions of my country, bringing low temperature and cold damage, rainstorms and floods to the main grain-producing areas in the above-mentioned regions, directly threatening my country's food security and the safety of people's lives and property. Numbering it is conducive to the accurate monitoring and forecasting business and scientific research.

In 2022, the Northeast Cold Vortex Key Laboratory, together with the Central Meteorological Observatory and the Liaoning Provincial Meteorological Observatory, officially numbered the Northeast Cold Vortex. In the Northeast Cold Vortex monitoring business, if a Northeast Cold Vortex is generated or moves in within the range of 105° to 145° east longitude and 35° to 60° north latitude, and the duration is ≥3 days, it will be numbered according to the order of the appearance of the Northeast Cold Vortex in the year. According to the numbering, the difference between the frequency of Northeast Cold Vortex activity in the current period and the historical average state can be compared. Forecasting business and scientific researchers can accurately record the Northeast Cold Vortex weather process that has caused a major impact, which is conducive to scientific research and review and summary, and improve the level of forecasting technology.

The first issue of the Northeast Cold Vortex Monitoring and Forecast Bulletin After the Northeast Cold Vortex begins to be numbered, the meteorological department will hold consultations on its possible impacts. When severe convection, heavy rain, and heavy snow will occur in parts of two or more provinces (autonomous regions, municipalities) in my country within the next 72 hours, or when large-scale 10-level gusts, strong cold waves, and sandstorms will occur in three or more provinces (autonomous regions, municipalities), the Northeast Cold Vortex Monitoring and Forecast Bulletin will be started 24 hours in advance.

【Cold wave 】 Highly disastrous and wide-ranging impact

Cold wave is a disastrous weather in winter, referring to cold air from high-latitude areas, which rapidly strengthens and invades middle and low-latitude areas under specific weather conditions, causing drastic drops in temperature, strong winds, rain and snow in the areas along the way.

When the cold air invades the south and reaches a certain standard, it is called a cold wave, which can occur all over the country and cause frost, freezing damage and other natural disasters. In the context of climate change, cold waves, as the most representative disastrous weather in the winter half of the year, have the characteristics of strong disaster-causing and wide-ranging impact, which will affect transportation, human health, agricultural production and other aspects.

Starting from November 2023, the cold wave processes occurring in my country have been numbered:

The cold wave number from November 5 to 7, 2023 is 202301. The cold wave numbering regulations stipulate that the cold wave-affected area must cover more than 4 provincial administrative regions.

This system helps to accurately describe and predict the impact of cold wave weather of different intensities. Since February 2023, based on the original cold wave business foundation and standard specifications, the Central Meteorological Observatory has formulated new specifications for cold wave survey and numbering business to number cold waves. This move will help to standardize the establishment of a cold wave historical disaster data set, improve the level of understanding of the occurrence, development and impact of typical cold wave weather processes in my country, and promote the high-quality development of cold wave weather monitoring and forecasting services. Scientific and standardized management of cold wave weather numbers will improve the accuracy and consistency of cold wave weather forecast services. Previously, the United States, the United Kingdom, Russia and other countries have carried out related businesses. The progress of this business is also conducive to enhancing my country's voice in international cooperation in the field of meteorology.

Whether it is a typhoon, a northeastern cold vortex, or a cold wave, numbering weather events with wide-ranging impacts has far-reaching significance. From the perspective of meteorological disaster prevention and mitigation, it is conducive to raising the public's awareness of disastrous weather and enhancing the whole society's ability to prevent and avoid meteorological disasters, thereby reducing disaster losses. From the perspective of forecasting and scientific research, it is conducive to enhancing the visibility and recognition of high-impact weather events, creating favorable conditions for accumulating and summarizing forecasting experience, upgrading and developing forecasting technology, reviewing and optimizing forecasting methods, and studying weather mechanisms.

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Source | Meteorological knowledge