Research on rain forecast with a forecast term of 10 – 90 days is a topic that Dr. Bui Minh Tuan (born in 1988) cherished during his master’s years at the University of Natural Sciences. “Rain is an extremely important factor for the development of most countries in the world, including Vietnam. If the rainfall is too heavy, it can lead to flooding, causing serious damage to people and material; But too little rainfall can cause droughts, lack of water for domestic use and destroy crops. Therefore, rain forecasting is always the top concern of meteorologists in the world, ”said Tuan. Although the meteorological industry in recent years has seen a strong development; weather forecasts for 5 days have the same accuracy as the one-day forecast of 30 years ago; … however, according to Mr. Tuan, this does not mean that in the next 30 years, the forecast will be 5 times more accurate than current. “There are big obstacles that the meteorological industry has not been able to overcome. Technically, the computer can help to make forecast bulletins that come monthly or longer, however, the reliability of the forecast report will drop very quickly after 5-7 days ”, said Tuan. . Currently, the theoretical foundations for short-term forecasting (from 1-5 days) have been gradually being finalized. Therefore, the weather forecast for this time period is relatively good. However, atmospheric changes on a longer time scale (from 10 to 90 days) are not fully understood. This is also one of the main reasons why the forecast is not reliable at this time. Those concerns have prompted Mr. Tuan to find laws related to the change of rain from 10 to 90 days, towards expanding the ability to forecast. Continuously from 2013 – 2019, Mr. Tuan went to “decode” the questions: Rain in Vietnam has cyclical fluctuations, especially the 10 – 90 day cycle or not? Are these variations between climatic regions? If rain in Vietnam has a strong fluctuation in a cycle of 10 – 90 days, which large-scale processes lead to the fluctuation of these cycles?, … To answer those questions, Tuan said it took him a year to read and understand the algorithms and build computational programs for large atmospheric data sets over the course of 30 years, in the period since 1980. – 2010. “These are complex algorithms, requiring high programming skills. But due to the lack of support from IT specialists, I encountered many difficulties in handling this problem ”. After the computational results have been obtained, analyzing the physical process based on those results is also a challenge. The reason is that Vietnam’s climate is very complicated, affected by many large circulation systems and has strong differentiation between regions. The characteristics of rain and the mechanism of precipitation in Vietnam still cause a lot of controversy in the meteorological community. Therefore, the selection of important aspects for analysis also requires a lot of time. Mr. Tuan also took another year to analyze all the results. What he collected during this time helped find the oscillation pattern of rain. The physical mechanisms involved in this volatility have also been shown. In particular, he also found a relationship of this oscillation with the occurrence of heavy rains in Vietnam. This brings a lot of value, because heavy rains are considered anomalous and difficult to predict. Tuan’s research is an important theoretical basis to expand the ability to predict rain and heavy rain from 10-25 days. Thanks to these results, by early 2019, his article was published in the Journal of Climate – a climate magazine of the American Meteorological Association. Mr. Tuan is a former student of Physics at the High School of Science and Technology. Because he is always curious about natural phenomena such as storms, tornadoes, thunderstorms, … he decided to enroll in the Department of Meteorology, Hydrology and Oceanography of the University of Natural Sciences, Vietnam National University. Cabinet. “When I entered school, I found Meteorology more interesting than what I thought. The ideal knowledge of mathematics and physics is quite distant, but it is applied very closely to explain natural phenomena. In addition, I also have access to modern technologies or to process data on mainframe systems. I also had the opportunity to do internships at local observatories and to participate in professional forecasting internships at the National Center for Hydrometeorological Forecasting. There, I played the role of forecasters, directly analyzing to create a forecast newsletter. It was a very wonderful experience for me ”. After graduating from university, he continued to study for masters and doctoral degrees at the University of Science. As a scientist trained in the country, Mr. Tuan assessed that in recent years, the meteorological industry in Vietnam has also had a great development. At the working place Tuan has been equipped with a supercomputer system for training and research. The latest achievements in areas such as remote sensing, data assimilation, high-performance computing, artificial intelligence, … have also been applied in weather forecasting. However, Mr. Tuan also frankly acknowledged, the support of information technology experts to maintain and operate this system well is still limited. Current researchers still have to be in charge of this additional area. Another “separate sadness”, according to Tuan, is loneliness in science. “The computer system started to exist, but for improvement, the human factor remains the prerequisite. In Vietnam today, the number of people who choose to follow the research path in this field is very small ”. The meteorology industry still seems to be “out of the general trajectory of development”, when after nearly 10 years, despite some changes, it is still slow and only motivated by a few individual individuals. There are not many people doing research in the same field, so it is very difficult to find an academic exchange. Part of the reason, according to Tuan, is that the support for young researchers is still relatively low compared to the general level of society. This is likely to lead to a crisis of high-quality human resources in the future. Currently, each training course in the Department of Meteorology of the University of Natural Sciences recruits only about 30-40 targets. While majors require people who are good at both Math, Physics or Programming, … these people often choose very few meteorology. “Right from the source of admission, this discipline has encountered difficulties. When we enroll in schools, students still know very little about the industry and only think this industry is mainly metrology, usually for the population of C because it relates to Geography. The main registration is for aspiration 2, aspiration 3, so they don’t really like and want to stick with the industry ”, said Tuan. According to the young doctor, this industry is still not respected because people still think, “rain and wind is the story of heaven”, seemingly very far away. But in fact, it greatly affects life, economy and society such as planning production activities, forecasting diseases and preventing natural disasters. “I hope in the coming time, the society will know about the Hydrometeorology industry, not only through the image of a young man in” Quiet Sa Pa “anymore. This is an interesting discipline and offers many opportunities for young people to be truly passionate about natural sciences ”.

According to the National Meteorological Agency, at present, the trend of temperature is gradually turning to a neutral state. With this development, the hurricane season this year is expected to come more wanted than every year, but need to be careful of strong storms; the rainy season can come early with extreme phenomena; risk occurs drought and local water shortage in Central and Central Highlands.

More information with VietnamPlus Electronic Newspaper reporter on the afternoon of April 15, Mr. Nguyen Van Huong, Head of Climate Forecast Department, National Hydrometeorological Forecast Center, said that from now until about May, it is unlikely to export storms and tropical depressions in the South China Sea. However, in the following months, storms and tropical depressions will begin to operate and increase in frequency, lasting until the end of 2021.

Specifically, in the period from June to July, storms and tropical depressions are likely to begin operating in the North East Sea and gradually increase the frequency, likely to affect the Northern region. and North Central region from August to September; affect provinces in Central and South Central from September to the end of this year.

“It is forecasted that this year there will be about 10-13 storms operating in the South China Sea, of which about half will affect the mainland. In which, strong storms will occur from September to October, “Huong said.

Also according to Mr. Huong, normally in the first half of the season (from June to September), tropical low pressure will concentrate in the North and the South China Sea, potentially affecting the North and North Central regions. ; in the second half of the season (from September to November), it will focus on the Middle and South East Sea, affecting the North Central Coast and returning to the South.

With the storm trend mentioned above, localities need to be careful of strong storms with complicated movements and cause strong winds at sea in months. stormy rainy season year 2021.

Regarding the trend of the rainy season, Mr. Huong said that this year’s rainy season is likely to come early in the Central Highlands and the South, from about the second half of April to the first half of May, thunderstorms and whirlwinds may occur. , hail, strong wind. In the last 6 months of 2021, rainfall tends to increase nationwide.

Illustration. (Source: VNA)

During the dry season months, the flow volume on most of the common rivers is approximately 15-40% lower than the average of many years in the same period, some rivers are 50% lower. Risk of drought and local water shortage in Central and Central Highlands.

In the flood season in 2021, the annual flood peak on the main rivers in the North, North Central region and Central Highlands is usually around 1-2 and above fluctuation 2; rivers in Yen Bai and Ninh Binh, from Quang Binh to Binh Thuan fluctuate 2-3, some rivers fluctuate 3.

The annual flood peak in the watershed of the Mekong River on Tien River in Tan Chau and Hau River in Chau Doc fluctuates 1-2, lower than the average flood peak of many years from 0.1-0.3m. In the dry season 2020-2021, salinity intrusion in the Mekong River Delta is at a high level but not as serious as the dry season in 2019-2020. Since May, saline intrusion in the Mekong Delta tends to decrease gradually.

The period of moderate and large floods in the North is likely to concentrate more in the second half of the flood season. On small rivers and streams, in the upstream areas, big floods, flash floods, and landslides are likely to occur; Inundation in cities and urban areas continues to be at risk from local heavy rains in the flood season months.

Before the weather trend mentioned above, the representative of Forecast Center Hydrometeorology The country said that the Ministry of Natural Resources and Environment will continue to direct hydro-meteorological forecasting and warning units, continuously monitoring, monitoring and updating daily on the website of the Ministry of Natural Resources. and Environment, General Department of Meteorology and Hydrology, soon provide detailed forecast information and warnings to functional agencies, media agencies and the people to prevent and avoid ../.