ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Volume 52,Issue 7,2026 Table of Contents
2026, 52(7):769-783.
DOI: 10.7519/j.issn.1000-0526.2025.072803
Abstract:
Based on the optimal typhoon track data of China Meteorological Administration (CMA) in 1979-2023, the National Meteorological Centre (NMC) real-time typhoon track and intensity data in 2024 and the monthly ERA5 reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF), we analyze and reveal the different features of typhoons generated over western North Pacific in summer and autumn of 2024 from the following three aspects: their generation, activity and landfall. The results show that the number of typhoons formed in western North Pacific in the summer of 2024 was smaller than normal, their generation sources were more northward and eastward, and their maximum intensities were weaker. No typhoons were generated in the early summer from 1 June to 18 July, but typhoons occurred frequently in midsummer, mostly following northwest- and north-direction tracks. The typhoons making landfall in China were fewer than usual, and their landfall intensities were relatively weak. However, they were more active in autumn. The number of the autumn typhoons ranked the third highest in history, their generation sources were more northward and westward, and their intensities were unusually strong. The autumn typhoon activities were characterized by distinct periodicity and clustering, with most following the westward or northwestward tracks. The number of landfall typhoons was significantly above the normal, and at the same time their landfall intensities were above the average. Further analysis suggests that the significant differences between the summer and autumn typhoons in 2024 were closely correlated to the multiple factors including the lag effect of sea surface temperature in the year following El Nino, the abnormal western North Pacific subtropical high, the phase transition of the Madden-Julian oscillation, the onset and withdrawal of summer monsoon in the South China Sea, and so on.
Based on the optimal typhoon track data of China Meteorological Administration (CMA) in 1979-2023, the National Meteorological Centre (NMC) real-time typhoon track and intensity data in 2024 and the monthly ERA5 reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF), we analyze and reveal the different features of typhoons generated over western North Pacific in summer and autumn of 2024 from the following three aspects: their generation, activity and landfall. The results show that the number of typhoons formed in western North Pacific in the summer of 2024 was smaller than normal, their generation sources were more northward and eastward, and their maximum intensities were weaker. No typhoons were generated in the early summer from 1 June to 18 July, but typhoons occurred frequently in midsummer, mostly following northwest- and north-direction tracks. The typhoons making landfall in China were fewer than usual, and their landfall intensities were relatively weak. However, they were more active in autumn. The number of the autumn typhoons ranked the third highest in history, their generation sources were more northward and westward, and their intensities were unusually strong. The autumn typhoon activities were characterized by distinct periodicity and clustering, with most following the westward or northwestward tracks. The number of landfall typhoons was significantly above the normal, and at the same time their landfall intensities were above the average. Further analysis suggests that the significant differences between the summer and autumn typhoons in 2024 were closely correlated to the multiple factors including the lag effect of sea surface temperature in the year following El Nino, the abnormal western North Pacific subtropical high, the phase transition of the Madden-Julian oscillation, the onset and withdrawal of summer monsoon in the South China Sea, and so on.
2026, 52(7):784-798.
DOI: 10.7519/j.issn.1000-0526.2026.040201
Abstract:
Based on daily precipitation and temperature data from 125 observation stations in Yunnan Province from 1961 to 2024, as well as NCEP/NCAR daily reanalysis data of atmospheric circulation in upper and lower levels, this paper investigates the criterion for the persistent drought events across winter and spring (WSPDE) in Yunnan. By analyzing the spatio-temporal characteristics of WSPDE in Yunnan, we have found that the WSPDE distribution in Yunnan is characterized by more in the northwest but less in the southeast. The regions with the highest drought frequency are mainly concentrated in the eastern part of northwest Yunnan, including Lijiang, Dali, and northern Chuxiong, while the southern parts of Honghe and Xishuangbanna have less drought events. The WSPDE standards for single station and provincial region in Yunnan are defined as follows. The station standard refers to the occurrence of light or above level drought in both winter and spring in a year, with moderate or above level drought occurring in one of two seasons. When 25 observation stations (20% of the total number of stations in Yunnan) experience the WSPDE in a year, and the average precipitation anomaly percentage in both winter and spring is ≤-10%, it is defined as a provincial WSPDE in Yunnan. Comparative analysis shows that this criterion can be reasonably used in identifying WSPDE in Yunnan. Further analysis reveals that the sustained maintenance of the geopotential height difference with high in the north and low in the south of the mid-low latitudes region at 500 hPa in East Asia, as well as anomalous anticyclones at 700 hPa in the Bay of Bengal has a significant impact on the WSPDE in Yunnan. The standard has an important scientific significance and application value for standardizing the WSPDE criterion for climate monitoring and prediction operations in Yunnan.
Based on daily precipitation and temperature data from 125 observation stations in Yunnan Province from 1961 to 2024, as well as NCEP/NCAR daily reanalysis data of atmospheric circulation in upper and lower levels, this paper investigates the criterion for the persistent drought events across winter and spring (WSPDE) in Yunnan. By analyzing the spatio-temporal characteristics of WSPDE in Yunnan, we have found that the WSPDE distribution in Yunnan is characterized by more in the northwest but less in the southeast. The regions with the highest drought frequency are mainly concentrated in the eastern part of northwest Yunnan, including Lijiang, Dali, and northern Chuxiong, while the southern parts of Honghe and Xishuangbanna have less drought events. The WSPDE standards for single station and provincial region in Yunnan are defined as follows. The station standard refers to the occurrence of light or above level drought in both winter and spring in a year, with moderate or above level drought occurring in one of two seasons. When 25 observation stations (20% of the total number of stations in Yunnan) experience the WSPDE in a year, and the average precipitation anomaly percentage in both winter and spring is ≤-10%, it is defined as a provincial WSPDE in Yunnan. Comparative analysis shows that this criterion can be reasonably used in identifying WSPDE in Yunnan. Further analysis reveals that the sustained maintenance of the geopotential height difference with high in the north and low in the south of the mid-low latitudes region at 500 hPa in East Asia, as well as anomalous anticyclones at 700 hPa in the Bay of Bengal has a significant impact on the WSPDE in Yunnan. The standard has an important scientific significance and application value for standardizing the WSPDE criterion for climate monitoring and prediction operations in Yunnan.
2026, 52(7):799-809.
DOI: 10.7519/j.issn.1000-0526.2026.011602
Abstract:
Hourly fixed-time precipitation data may underestimate the characteristics of heavy precipitation at the hourly scale. To gain a deeper understanding of the variation patterns of hourly heavy precipitation, utilizing the minutely precipitation observation data collected by 123 national meteorological stations in Shandong Province from June to September during the flood seasons of 2004-2024, we compare the differences between the 60 min sliding window and hourly fixed-time statistical methods in identifying heavy precipitation events, and quantitatively assess the impact of the two methods on the frequency, intensity and spatio-temporal distribution of heavy precipitation. The results indicate that the 60 min sliding window method can capture heavy precipitation events more comprehensively than the hourly fixed-time method. The average frequency of heavy precipitation across the whole province is 124.3 times by means of the 60 min sliding window method, and it is 1.47 times that of the hourly fixed-time method (84.3 times), with the ratio of each station ranging between 1.31 and 1.81. The maximum precipitation captured by the 60 min sliding window method is 10.0 mm more on average, exceeding 30.0 mm for some stations. The spatial distributions of the heavy precipitation by two methods are generally in line, but the 60 min sliding window method reveals even greater spatial variability and stronger extremity of heavy precipitation. The 60 min sliding window method also more clearly shows the increasing trends in both frequency and intensity of heavy precipitation, with climatic tendency rates being 1.291 times per decade and 4.514 mm per decade, respectively. Moreover, the monthly and daily variation characteristics of heavy precipitation are more distinct by using the 60 min sliding window method, particularly in the high-frequency periods from July to August and from afternoon to early morning. The traditional hourly fixed-time statistical mehtod underestimates the frequency and extreme intensity of short-duration heavy precipitation. In contrast, the 60 min sliding window method can provide a more accurate representation of heavy precipitation characteristics, so it is of great application values for improving the accuracy of rainstorm monitoring and early warning capabilities for disasters.
Hourly fixed-time precipitation data may underestimate the characteristics of heavy precipitation at the hourly scale. To gain a deeper understanding of the variation patterns of hourly heavy precipitation, utilizing the minutely precipitation observation data collected by 123 national meteorological stations in Shandong Province from June to September during the flood seasons of 2004-2024, we compare the differences between the 60 min sliding window and hourly fixed-time statistical methods in identifying heavy precipitation events, and quantitatively assess the impact of the two methods on the frequency, intensity and spatio-temporal distribution of heavy precipitation. The results indicate that the 60 min sliding window method can capture heavy precipitation events more comprehensively than the hourly fixed-time method. The average frequency of heavy precipitation across the whole province is 124.3 times by means of the 60 min sliding window method, and it is 1.47 times that of the hourly fixed-time method (84.3 times), with the ratio of each station ranging between 1.31 and 1.81. The maximum precipitation captured by the 60 min sliding window method is 10.0 mm more on average, exceeding 30.0 mm for some stations. The spatial distributions of the heavy precipitation by two methods are generally in line, but the 60 min sliding window method reveals even greater spatial variability and stronger extremity of heavy precipitation. The 60 min sliding window method also more clearly shows the increasing trends in both frequency and intensity of heavy precipitation, with climatic tendency rates being 1.291 times per decade and 4.514 mm per decade, respectively. Moreover, the monthly and daily variation characteristics of heavy precipitation are more distinct by using the 60 min sliding window method, particularly in the high-frequency periods from July to August and from afternoon to early morning. The traditional hourly fixed-time statistical mehtod underestimates the frequency and extreme intensity of short-duration heavy precipitation. In contrast, the 60 min sliding window method can provide a more accurate representation of heavy precipitation characteristics, so it is of great application values for improving the accuracy of rainstorm monitoring and early warning capabilities for disasters.
2026, 52(7):810-821.
DOI: 10.7519/j.issn.1000-0526.2026.051401
Abstract:
Using conventional observations, surface automatic meteorological station data, NCEP/FNL reanalysis, Doppler radar data, and WRF model simulations, this paper studies a severe convective event triggered by the collision between a gust front and a sea-breeze front in the Xiamen Region, and also analyzes its underlying mechanisms. The results show that this event occurred at the edge of the subtropical high, where upper-level divergence overlapped with low-level convergence. An unstable thermodynamic stratification characterized by dry upper levels and moist lower levels, together with strong thermal instability, provided a favorable environment for convective development. The cold outflow generated by earlier convective cells expanded outward forming a gust front, while the sea-breeze front developed continuously along the Xiamen coast. After the two boundaries collided near the urban area of Xiamen, low-level convergence and local lifting were markedly enhanced, thereby initiating the severe convection. WRF simulations further indicate that following the collision, the shallow-layer specific humidity in the collision zone increased by about 2.5 g·kg-1, the maximum convective available potential energy increased by more than 1000 J·kg-1, and the vorticity intensified to 25×10-4 s-1, which indicate significant enhancement of moisture supply, instability, and dynamic lifting. The convergence-induced ascending motion allowed air parcels to overcome the level of free convection, thereby initiating and sustaining convection. Subsequently, convective cells near the collision zone merged and triggered a cloud-bridge cell, which further developed into a multicellular merging process. Thereafter, a surface convergence line and shallow shear system on the rear side of the collision area maintained a deeper convergence-ascending structure, and with sufficient moisture and instability, a subsequent convective regeneration process occurred. The findings could provide a useful implication for nowcasting and warning of local severe convection in Xiamen and other coastal regions.
Using conventional observations, surface automatic meteorological station data, NCEP/FNL reanalysis, Doppler radar data, and WRF model simulations, this paper studies a severe convective event triggered by the collision between a gust front and a sea-breeze front in the Xiamen Region, and also analyzes its underlying mechanisms. The results show that this event occurred at the edge of the subtropical high, where upper-level divergence overlapped with low-level convergence. An unstable thermodynamic stratification characterized by dry upper levels and moist lower levels, together with strong thermal instability, provided a favorable environment for convective development. The cold outflow generated by earlier convective cells expanded outward forming a gust front, while the sea-breeze front developed continuously along the Xiamen coast. After the two boundaries collided near the urban area of Xiamen, low-level convergence and local lifting were markedly enhanced, thereby initiating the severe convection. WRF simulations further indicate that following the collision, the shallow-layer specific humidity in the collision zone increased by about 2.5 g·kg-1, the maximum convective available potential energy increased by more than 1000 J·kg-1, and the vorticity intensified to 25×10-4 s-1, which indicate significant enhancement of moisture supply, instability, and dynamic lifting. The convergence-induced ascending motion allowed air parcels to overcome the level of free convection, thereby initiating and sustaining convection. Subsequently, convective cells near the collision zone merged and triggered a cloud-bridge cell, which further developed into a multicellular merging process. Thereafter, a surface convergence line and shallow shear system on the rear side of the collision area maintained a deeper convergence-ascending structure, and with sufficient moisture and instability, a subsequent convective regeneration process occurred. The findings could provide a useful implication for nowcasting and warning of local severe convection in Xiamen and other coastal regions.
2026, 52(7):822-833.
DOI: 10.7519/j.issn.1000-0526.2025.100701
Abstract:
Based on conventional observation data and Suizhou S-band dual-polarization weather radar observation data, the short-time heavy rainfall events are classified into strong synoptic-scale system forcing type (strong forcing type) and weak synoptic-scale system forcing type (weak forcing type) according to the weather circulation patterns. The distribution characteristics and dual-polarization radar echo characteristics of the two are comparatively analyzed. The results show that the strong forcing type of short-time heavy rainfall occurs more frequently at more stations, covering wider areas and lasting longer. July has the highest frequency of this type of heavy rainfall, followed by June and then August. Dahong Mountain and Tongbai Mountain are the areas where the strong forcing type of heavy rainfall most frequently. The daily variation characteristics of such rainfall show a three-peak pattern, with the highest occurrence from 05:00 BT to 08:00 BT, then from 22:00 BT to 01:00 BT the next day, and at around 15:00 BT in order. In terms of the weak forcing type of short-time heavy rainfall, its occurrence frequency is basically the same in July and August, with the least in June. The distribution of its high-frequency areas is scattered, but mountainous areas are still the high-frequency areas. Its daily variation follows a unimodal distribution, with the peak occurring at 15:00 BT. Both types of short-time heavy rainfall have the characteristics of higher rainfall intensity, the corresponding stronger echo intensity, higher concentration of liquid particles, higher echo top, and larger diameters of liquid particles. At the same rainfall intensity level, the two types of heavy rainfall do not show significant differences in composite reflectivity, horizontal reflectivity at 1 km height, and echo top height, and they all have low centroid characteristics, with the strong forcing type having more obvious low centroid characteristics. However, the interval and average values of the 1 km differential reflectivity and specific differential phase for the strong forcing type are significantly smaller than those for the weak forcing type, while the interval and average values of the 1 km correlation coefficient are slightly larger than those for the weak forcing type.
Based on conventional observation data and Suizhou S-band dual-polarization weather radar observation data, the short-time heavy rainfall events are classified into strong synoptic-scale system forcing type (strong forcing type) and weak synoptic-scale system forcing type (weak forcing type) according to the weather circulation patterns. The distribution characteristics and dual-polarization radar echo characteristics of the two are comparatively analyzed. The results show that the strong forcing type of short-time heavy rainfall occurs more frequently at more stations, covering wider areas and lasting longer. July has the highest frequency of this type of heavy rainfall, followed by June and then August. Dahong Mountain and Tongbai Mountain are the areas where the strong forcing type of heavy rainfall most frequently. The daily variation characteristics of such rainfall show a three-peak pattern, with the highest occurrence from 05:00 BT to 08:00 BT, then from 22:00 BT to 01:00 BT the next day, and at around 15:00 BT in order. In terms of the weak forcing type of short-time heavy rainfall, its occurrence frequency is basically the same in July and August, with the least in June. The distribution of its high-frequency areas is scattered, but mountainous areas are still the high-frequency areas. Its daily variation follows a unimodal distribution, with the peak occurring at 15:00 BT. Both types of short-time heavy rainfall have the characteristics of higher rainfall intensity, the corresponding stronger echo intensity, higher concentration of liquid particles, higher echo top, and larger diameters of liquid particles. At the same rainfall intensity level, the two types of heavy rainfall do not show significant differences in composite reflectivity, horizontal reflectivity at 1 km height, and echo top height, and they all have low centroid characteristics, with the strong forcing type having more obvious low centroid characteristics. However, the interval and average values of the 1 km differential reflectivity and specific differential phase for the strong forcing type are significantly smaller than those for the weak forcing type, while the interval and average values of the 1 km correlation coefficient are slightly larger than those for the weak forcing type.
2026, 52(7):834-845.
DOI: 10.7519/j.issn.1000-0526.2025.072402
Abstract:
Based on a persistent severe convective event that occurred in March 2023 over the hilly terrain in the southeastern coastal regions of China, we comparatively analyze the surface spectral characteristics of precipitation particles associated with isolated convective storms and squall-line convective systems by using the S-band dual-polarization radar data and the observations of surface precipitation particle spectra. The results show that the isolated convective storms during the hailfall concentration area exhibit larger particle sizes, more complex spectral structures, more pronounced fluctuations in total particle number concentration, and greater dispersion in the velocity and size spectra. All these features indicate that the internal ice-phase processes are even more vigorous in this stage. In contrast, squall-line convection systems are characterized by high-density hailstones, a relatively high concentration of small raindrops, and simpler spectral structures. For the two convective types, the peaks in precipitation particle concentration both appear near the high-reflectivity precipitation region following the concentrated hailfall stage, accompanied by narrowing spectral width and reduction in large particles. Moreover, the precipitation process is further divided into four distinct stages, each showing markedly different spectral characteristics. These findings could enhance the understanding of the microphysical processes of isolated and squall-line hail clouds and provide scientific support for short-time nowcasting and hail suppression operations.
Based on a persistent severe convective event that occurred in March 2023 over the hilly terrain in the southeastern coastal regions of China, we comparatively analyze the surface spectral characteristics of precipitation particles associated with isolated convective storms and squall-line convective systems by using the S-band dual-polarization radar data and the observations of surface precipitation particle spectra. The results show that the isolated convective storms during the hailfall concentration area exhibit larger particle sizes, more complex spectral structures, more pronounced fluctuations in total particle number concentration, and greater dispersion in the velocity and size spectra. All these features indicate that the internal ice-phase processes are even more vigorous in this stage. In contrast, squall-line convection systems are characterized by high-density hailstones, a relatively high concentration of small raindrops, and simpler spectral structures. For the two convective types, the peaks in precipitation particle concentration both appear near the high-reflectivity precipitation region following the concentrated hailfall stage, accompanied by narrowing spectral width and reduction in large particles. Moreover, the precipitation process is further divided into four distinct stages, each showing markedly different spectral characteristics. These findings could enhance the understanding of the microphysical processes of isolated and squall-line hail clouds and provide scientific support for short-time nowcasting and hail suppression operations.
7 Analysis of Characteristics of a Long-Lived Freezing Rain and Ice Pellet Event in Southern Shandong
2026, 52(7):846-856.
DOI: 10.7519/j.issn.1000-0526.2025.080501
Abstract:
A rare weather event featuring a long-lived freezing rain and ice pellets transitioning to snow occurred in the southern Shandong Region from 20 to 21 February 2024. Using conventional observational data, wind-profiling radar data, raindrop spectrum data and ERA5 reanalysis data, this article analyzes this event. The results indicate as follows. The event was characterized by return-flow precipitation. A southwest warm and humid airflow ahead of the upper-level trough slid upwards along a cold pad caused by a significant temperature drop due to the low-level strong cold air. The interaction between the mid-level warm and humid airflow and the low-level northeastern airflow formed a strong inversion temperature, and the “cold-warm-cold” vertical temperature structure was maintained for a long time, leading to a 12 h period of freezing rain and ice pellet weather. Both freezing rain and ice pellets exhibited typical characteristics of ice-phase melting. The ground temperature during freezing rain was higher, the starting height of the warm layer was lower, and both the thickness and intensity of the warm layer were greater, while the thickness and intensity of the cold layer were smaller. Raindrop spectrum data show that there was no significant difference in the particle size distribution characteristics between freezing rain and ice pellets. Both had features of small particle diameter, low particle number concentration, low precipitation intensity, and high falling velocity. Their velocity curves were similar to those of rainfall. Freezing rain had slightly larger particle diameter and fewer particle number concentration than ice pellets. During the snowfall phase, the spectrum was widened, characterized by large particle diameter, high particle number concentration, high precipitation intensity, and low falling velocity.
A rare weather event featuring a long-lived freezing rain and ice pellets transitioning to snow occurred in the southern Shandong Region from 20 to 21 February 2024. Using conventional observational data, wind-profiling radar data, raindrop spectrum data and ERA5 reanalysis data, this article analyzes this event. The results indicate as follows. The event was characterized by return-flow precipitation. A southwest warm and humid airflow ahead of the upper-level trough slid upwards along a cold pad caused by a significant temperature drop due to the low-level strong cold air. The interaction between the mid-level warm and humid airflow and the low-level northeastern airflow formed a strong inversion temperature, and the “cold-warm-cold” vertical temperature structure was maintained for a long time, leading to a 12 h period of freezing rain and ice pellet weather. Both freezing rain and ice pellets exhibited typical characteristics of ice-phase melting. The ground temperature during freezing rain was higher, the starting height of the warm layer was lower, and both the thickness and intensity of the warm layer were greater, while the thickness and intensity of the cold layer were smaller. Raindrop spectrum data show that there was no significant difference in the particle size distribution characteristics between freezing rain and ice pellets. Both had features of small particle diameter, low particle number concentration, low precipitation intensity, and high falling velocity. Their velocity curves were similar to those of rainfall. Freezing rain had slightly larger particle diameter and fewer particle number concentration than ice pellets. During the snowfall phase, the spectrum was widened, characterized by large particle diameter, high particle number concentration, high precipitation intensity, and low falling velocity.
2026, 52(7):857-868.
DOI: 10.7519/j.issn.1000-0526.2026.051302
Abstract:
Addressing the persistent demand for historical analogue references in operational weather forecasting and the deficiencies of traditional retrieval methods in efficiency and objectivity, this paper proposes a rapid retrieval technology for historical analog weather events based on image fingerprint synergy. This technology employs fingerprint similarity detection algorithms from imageology and establishes a similarity quantification method and single-variable synergistic query algorithm. Guided by synoptic principles and considering the coupling characteristics between upper-air circulation and surface variables, we design a multi-variable synergistic query algorithm to more accurately identify historical precipitation fields and the corresponding circulation patterns similar to a target weather process. Based on these techniques, a historical analog weather retrieval platform is developed and has been operationally trialed in the National Meteorological Centre, demonstrating good application potential and practical value in forecasting several weather events. Statistical verification indicates that the similar cases retrieved by this method significantly outperform climatology in terms of anomaly correlation coefficient and root mean square error. Finally, this paper discusses future development directions for technology, particularly in algorithm optimization, objective evaluation, and deepening application.
Addressing the persistent demand for historical analogue references in operational weather forecasting and the deficiencies of traditional retrieval methods in efficiency and objectivity, this paper proposes a rapid retrieval technology for historical analog weather events based on image fingerprint synergy. This technology employs fingerprint similarity detection algorithms from imageology and establishes a similarity quantification method and single-variable synergistic query algorithm. Guided by synoptic principles and considering the coupling characteristics between upper-air circulation and surface variables, we design a multi-variable synergistic query algorithm to more accurately identify historical precipitation fields and the corresponding circulation patterns similar to a target weather process. Based on these techniques, a historical analog weather retrieval platform is developed and has been operationally trialed in the National Meteorological Centre, demonstrating good application potential and practical value in forecasting several weather events. Statistical verification indicates that the similar cases retrieved by this method significantly outperform climatology in terms of anomaly correlation coefficient and root mean square error. Finally, this paper discusses future development directions for technology, particularly in algorithm optimization, objective evaluation, and deepening application.
2026, 52(7):869-879.
DOI: 10.7519/j.issn.1000-0526.2026.050201
Abstract:
Based on China’s design codes for building structures and major overhead transmission lines, this study adopts the generalized extreme value distribution theory and historical surface meteorological observation data to calculate the basic wind pressures at different return-periods for meteorological observation stations. The maximum wind pressure generated by the maximum wind and the extreme wind pressure generated by extreme wind are taken as the disaster-inducing factors of typhoon-generated strong wind for transmission lines, and a disaster assessment model is established by combining the wind pressure disaster threshold indicators of different types of transmission lines: low-voltage, medium-voltage, high-voltage, and ultra-high voltage and above. According to the impact of typhoon-generated strong wind on transmission lines, the disaster level is divided into four grades: medium, relatively high, high and extremely high, and the corresponding disaster impacts on different types of transmission lines are specified. The disaster data from the meteorological disaster management system of the China Meteorological Administration between 2012 and 2023 are used to verify the rationality of the developed disaster assessment model for transmission lines under typhoon-generated strong wind. Among the 205 samples with transmission line damage or power supply interruption caused by typhoons, the model identifies 183 samples with disaster risk on transmission lines, achieving an assessment accuracy of 89.3%. Out of the 162 samples of power disasters caused by typhoons with typhoon-level or above intensity landing in China, the model identifies 146 samples with disaster risk on transmission lines. Among these, the proportions of samples with medium, relatively high, high and extremely high grades in the total samples are 26.5%, 36.4%, 14.8% and 12.3% respectively, and the assessment accuracy reaches 90.1%, indicating that the overall performance of the model is satisfactory. The developed assessment model can conduct disaster pre-assessment and rapid post-assessment by combining typhoon forecast or observation data. Thus provide reference for typhoon meteorological services for the power industry.
Based on China’s design codes for building structures and major overhead transmission lines, this study adopts the generalized extreme value distribution theory and historical surface meteorological observation data to calculate the basic wind pressures at different return-periods for meteorological observation stations. The maximum wind pressure generated by the maximum wind and the extreme wind pressure generated by extreme wind are taken as the disaster-inducing factors of typhoon-generated strong wind for transmission lines, and a disaster assessment model is established by combining the wind pressure disaster threshold indicators of different types of transmission lines: low-voltage, medium-voltage, high-voltage, and ultra-high voltage and above. According to the impact of typhoon-generated strong wind on transmission lines, the disaster level is divided into four grades: medium, relatively high, high and extremely high, and the corresponding disaster impacts on different types of transmission lines are specified. The disaster data from the meteorological disaster management system of the China Meteorological Administration between 2012 and 2023 are used to verify the rationality of the developed disaster assessment model for transmission lines under typhoon-generated strong wind. Among the 205 samples with transmission line damage or power supply interruption caused by typhoons, the model identifies 183 samples with disaster risk on transmission lines, achieving an assessment accuracy of 89.3%. Out of the 162 samples of power disasters caused by typhoons with typhoon-level or above intensity landing in China, the model identifies 146 samples with disaster risk on transmission lines. Among these, the proportions of samples with medium, relatively high, high and extremely high grades in the total samples are 26.5%, 36.4%, 14.8% and 12.3% respectively, and the assessment accuracy reaches 90.1%, indicating that the overall performance of the model is satisfactory. The developed assessment model can conduct disaster pre-assessment and rapid post-assessment by combining typhoon forecast or observation data. Thus provide reference for typhoon meteorological services for the power industry.
2026, 52(7):880-892.
DOI: 10.7519/j.issn.1000-0526.2026.050703
Abstract:
Using station observation data and the NCEP/NCAR reanalysis data, this paper analyzes the main climatic characteristics, large-scale atmospheric circulation anomalies, and East Asian winter monsoon features in China during the winter of 2025/2026 (December 2025 to February 2026), with a focus on the causes of the abnormally active sand-dust weather in February 2026. The results show that in the winter of 2025/2026, the national average temperature was -1.5℃, which is 1.5℃ higher than the climatological average, ranking as the second highest for the same period since 1961. The national average precipitation was 27.4 mm, 35.3% less than normal, with a spatial distribution of more precipitation anomaly in the north and less in the south. The 500 hPa geopotential height field over the mid-high latitudes of Eurasia was dominated by a zonal circulation, the westerly was in a relatively straight pattern, and the East Asian winter monsoon was weaker than normal. During the 2025/2026 winter, a total of six sand-dust weather events occurred in China, 4.2 times more than the climatological average. Among them, there were three sandstorm events, which was 2.7 times more than the climatological average (0.3 times). Moreover, the number of sand-dust days reached 7.7 d, the highest in winter since 1991. The analysis on the formation causes of sand-dust weather indicates that the sand source areas experienced significantly warm and dry conditions in this winter. Precipitation was below average but temperature was above average. This situation led to low vegetation coverage and a substantial reduction in surface resistance to wind erosion, thereby providing abundant material conditions for sandstorms. Against this background, the synergistic effect of strong cold air and the Mongolian cyclone generated a large pressure gradient triggering extreme gale winds. This condition, combined with enhanced thermal lifting due to large temperature differences between upper and lower levels, resulted in large amounts of sands and dusts being lifted into the atmosphere and transported to downwind areas. Besides, global climate warming has further exacerbated the drying trend in the sand source regions, increasing the frequency of the superposition of such warm-dry conditions with intense weather processes.
Using station observation data and the NCEP/NCAR reanalysis data, this paper analyzes the main climatic characteristics, large-scale atmospheric circulation anomalies, and East Asian winter monsoon features in China during the winter of 2025/2026 (December 2025 to February 2026), with a focus on the causes of the abnormally active sand-dust weather in February 2026. The results show that in the winter of 2025/2026, the national average temperature was -1.5℃, which is 1.5℃ higher than the climatological average, ranking as the second highest for the same period since 1961. The national average precipitation was 27.4 mm, 35.3% less than normal, with a spatial distribution of more precipitation anomaly in the north and less in the south. The 500 hPa geopotential height field over the mid-high latitudes of Eurasia was dominated by a zonal circulation, the westerly was in a relatively straight pattern, and the East Asian winter monsoon was weaker than normal. During the 2025/2026 winter, a total of six sand-dust weather events occurred in China, 4.2 times more than the climatological average. Among them, there were three sandstorm events, which was 2.7 times more than the climatological average (0.3 times). Moreover, the number of sand-dust days reached 7.7 d, the highest in winter since 1991. The analysis on the formation causes of sand-dust weather indicates that the sand source areas experienced significantly warm and dry conditions in this winter. Precipitation was below average but temperature was above average. This situation led to low vegetation coverage and a substantial reduction in surface resistance to wind erosion, thereby providing abundant material conditions for sandstorms. Against this background, the synergistic effect of strong cold air and the Mongolian cyclone generated a large pressure gradient triggering extreme gale winds. This condition, combined with enhanced thermal lifting due to large temperature differences between upper and lower levels, resulted in large amounts of sands and dusts being lifted into the atmosphere and transported to downwind areas. Besides, global climate warming has further exacerbated the drying trend in the sand source regions, increasing the frequency of the superposition of such warm-dry conditions with intense weather processes.
2026, 52(7):893-904.
DOI: 10.7519/j.issn.1000-0526.2026.070101
Abstract:
In April 2026, the polar vortex in the Northern Hemisphere was distributed in an eccentric pattern and the Ural blocking high developed abnormally. The path of cold air affecting East Asia was by north, and the cold air was relatively weak. The national average temperature was 1.4 ℃ higher than the climatological average, ranking the fourth highest since 1961. The national average precipitation was 27% above the normal, and the rainfall over regions south of the Yangtze River was extraordinarily abundant. Especially, the monthly precipitation in Hunan Province broke the historical monthly record. Multiple types of disastrous weather with prominent extremities occurred this month. On 9 April, a large-scale hail event occurred in the Jiangnan Region (area south of the Yangtze River), and extreme thunderstorm gales affected central and northern Zhejiang Province with record-breaking non-typhoon high winds observed over the Zhoushan sea area. From 26 to 27 April, during the torrential rain event in southern Guangxi, the daily rainfall at 14 stations including Qinzhou Station broke the historical daily rainfall records in April. Four sand-dust events including one severe sandstorm, and six severe convective weather events occurred across China this month. A large-scale heavy sandstorm occurred in northern China from 17 to 20 April. Affected by the Mongolian cyclone, this sandstorm event featured the west-strong and east-weak pattern and dual-channel transport. Overall, during this month, the records of daily precipitation, wind speed and temperature in spring were broken in many places, and these disasters exerted various impacts on production, daily life and ecological environment.
In April 2026, the polar vortex in the Northern Hemisphere was distributed in an eccentric pattern and the Ural blocking high developed abnormally. The path of cold air affecting East Asia was by north, and the cold air was relatively weak. The national average temperature was 1.4 ℃ higher than the climatological average, ranking the fourth highest since 1961. The national average precipitation was 27% above the normal, and the rainfall over regions south of the Yangtze River was extraordinarily abundant. Especially, the monthly precipitation in Hunan Province broke the historical monthly record. Multiple types of disastrous weather with prominent extremities occurred this month. On 9 April, a large-scale hail event occurred in the Jiangnan Region (area south of the Yangtze River), and extreme thunderstorm gales affected central and northern Zhejiang Province with record-breaking non-typhoon high winds observed over the Zhoushan sea area. From 26 to 27 April, during the torrential rain event in southern Guangxi, the daily rainfall at 14 stations including Qinzhou Station broke the historical daily rainfall records in April. Four sand-dust events including one severe sandstorm, and six severe convective weather events occurred across China this month. A large-scale heavy sandstorm occurred in northern China from 17 to 20 April. Affected by the Mongolian cyclone, this sandstorm event featured the west-strong and east-weak pattern and dual-channel transport. Overall, during this month, the records of daily precipitation, wind speed and temperature in spring were broken in many places, and these disasters exerted various impacts on production, daily life and ecological environment.
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ISSN:1000-0526 CN:11-2282/P