Search Results (24)

Hailstorms frequently develop in Yun-Gui Plateau, Western China, which bring about significant economic damage. Due to the high terrain, these storms are typically shallow, rapidly evolving, and challenging to forecast. An X-band phased-array radar (XPAR) network is set up at Weining in Yun-Gui Plateau to study these storms. To explore these XPAR data for numerical prediction of hailstorms in this region, we implement the Weather Research and Forecast (WRF) model and Hydrometeor and Latent Heat Nudging (HLHN) method to assimilate the data and conduct prediction experiments. The XPAR data was evaluated along with the operational Severe Weather Automatic Nowcast (SWAN) system radar mosaic data. Furthermore, a humidity adjustment scheme is used to overcome inconsistency of the humidity field and related prediction errors. The model results show that in comparison to the SWAN data, assimilating XPAR data in 1-min intervals significantly reduces the model error, and improves the representation of rapid hail cloud evolution. Additionally, adjusting the model humidity based on vertically integrated liquid (VIL) derived from the radar data can effectively correct model analyses of humidity and temperatures, suppressing spurious convection, thus improving the hailstorm forecast. Overall, we recommend joint assimilation of the high spatiotemporal resolution XPAR data along with SWAN radar data with the improved WRF-HLHN for hailstorm prediction over the study region, and the algorithm can be promptly adapted to forecasting hailstorms in other regions. Full article

Hailstorms represent one of the most damaging convective hazards for agriculture, yet quantifying their impacts at a landscape scale remains challenging due to their localized and short-lived nature. In this study, we combine weather radar parameters and Sentinel-2 multispectral imagery to assess vegetation damage caused by two major hail events in northeastern Romania: Rădăuți (17 July 2016) and Dolhasca (30 July 2020). Radar-derived hail kinetic energy (HKE) was used as a rapid temporal indicator of hail occurrence, with a threshold of 300 J m⁻² applied to delineate potentially affected areas. Sentinel-2 Level-1C imagery, selected under strict temporal and cloud cover criteria, was processed to generate pre- and post-event Normalized Difference Vegetation Index (NDVI) maps, from which NDVI differences (ΔNDVI) were computed. Thresholds of 0.10 and 0.20 were applied to identify moderate and severe vegetation stress, respectively. The results demonstrate strong spatial correspondence between radar-derived HKE cores and Sentinel-2 ΔNDVI reductions. In Rădăuți, where only one post-event image was available, ΔNDVI thresholds identified between 2236 and 5856 ha of affected vegetation within the HKE > 300 J m⁻² zone. In Dolhasca, where three post-event images were available (5, 8, and 15 days), the analysis revealed 6200–9100 ha affected at 5 days, decreasing to 4800–7200 ha at 8 days, and further to 3100–5600 ha at 15 days post-event. This temporal gradient highlights both the recovery of vegetation and the diminishing sensitivity of the ΔNDVI signal with increasing time elapsed since the event. Analysis by land use classes showed arable fields to be the most sensitive, followed by orchards and pastures, while forests exhibited smaller but persistent declines. This study demonstrates the robustness of integrating radar-derived hail kinetic energy with Sentinel-2 NDVI differencing for the spatiotemporal assessment of hail damage. The approach provides both rapid detection and temporally resolved mapping of hail damage, underlining the critical role of time as a determining factor in impact assessments. These findings have strong implications for operational crop monitoring, disaster response, and risk management in hail-prone regions. Full article

Hailstones exhibit variations in diameter and impact objects at different velocities influenced by airflow. The extent of damage inflicted by hailstorms is contingent upon both the size and speed of the hailstones. Accurately simulating hailstones is essential for conducting impact tests. In this research, artificial hailstones were created using a polyvinyl acetate (PVA) additive. Previous investigations indicate that a mixture comprising 12% PVA and 88% demineralized water is most effective in replicating the behavior of natural hailstones. The primary objective of this study is to establish an experimental setup for assessing the impact of hailstones on aircraft canopies. To support this goal, specific requirements for impact testing were outlined. Dynamic impact tests were conducted using two different aircraft dimensions. Artificial hailstones of 20 mm and 50 mm in diameter were successfully manufactured for the experiments. The designated velocities for these artificial hailstones were 20 m/s, 30 m/s, 60 m/s, and 120 m/s, for which the necessary air pressures were calculated. Experimental results confirmed that artificial hailstones of varying diameters could be effectively produced and that they impacted predetermined areas on the aircraft canopies. However, the study also found that artificial hailstones traveling at velocities exceeding 120 m/s failed to produce visible deformation on the aircraft canopies. Full article

This study examines the effects of hailstorms on photovoltaic (PV) modules, focussing on damage mechanisms, testing standards, numerical simulations, damage detection techniques, and mitigation strategies. A comprehensive review of the recent literature (2017–2025), experimental results, and case studies is complemented by advanced simulation methods such as finite element analysis (FEA) and smoothed particle hydrodynamics (SPH). The research emphasises the crucial role of protective glass thickness, cell type, number of busbars, and quality of lamination in improving hail resistance. While international standards such as IEC 61215 specify test protocols, actual hail events often exceed these conditions, leading to glass breakage, micro-cracks, and electrical faults. Numerical simulations confirm that thicker glass and optimised module designs significantly reduce damage and power loss. Detection methods, including visual inspection, thermal imaging, electroluminescence, and AI-driven imaging, enable rapid identification of both visible and hidden damage. The study also addresses the financial risks associated with hail damage and emphasises the importance of insurance and preventative measures. Recommendations include the use of certified, robust modules, protective covers, optimised installation angles, and regular inspections to mitigate the effects of hail. Future research should develop lightweight, impact-resistant materials, improve simulation modelling to better reflect real-world hail conditions, and improve AI-based damage detection in conjunction with drone inspections. This integrated approach aims to improve the durability and reliability of PV modules in hail-prone regions and support the sustainable use of solar energy amidst increasing climatic challenges. Full article

Hailstorms, exacerbated by global warming, inflict escalating economic losses on infrastructure, yet existing research overlooks wind–hail synergy in impact dynamics. This study employs a wind-tunnel-integrated hail impact simulator to analyze how wind speed, hail diameter, and velocity collectively influence impact behavior. Key results reveal that higher wind speeds shorten the impact duration, accelerate peak force attainment, and amplify peak forces by up to 18.9% compared to windless conditions. Smaller hailstones exhibit reduced wind sensitivity, while combined increases in wind speed and hail diameter/velocity proportionally elevate peak forces. Momentum transfer from wind-driven fragmented hail clusters enhances force generation, demonstrating wind’s critical role in damage potential. A multivariate regression model predicting peak impact loads is proposed, offering actionable insights for wind–hail-resistant structural design. Full article

In Europe, climate change has a big impact on agriculture, due to an increase in the frequency and severity of extreme weather events. Many and prolonged droughts, heatwaves, floods, and hailstorms cause major economic losses that affect crop quality and generate instability in supply chains. In this study, we analyse the evolution of extreme weather events across Europe starting from the 1980s. The economic losses caused by extreme events were divided into three categories: heatwaves, frost, and fires; floods; and storms. In order to identify the trend and any shifts of the trend of the extreme weather events, we calculated moving averages over different periods: 5, 10, 20, and 30 years. The moving average analysis shows how climate change has altered from causing isolated and temporary economic losses to generate a consistent upward trend in losses, with an increasingly significant impact in the short, medium, and long term. In the second part of this study, we conducted a correlation analysis between the economic losses caused by extreme weather events and variations in property insurance premiums (fire and other property damage—which includes crop insurance premiums) and we calculated correlation coefficients directly, with a one-year lag, and with a two-year lag. Thus, we analysed whether insurance markets respond immediately to incurred losses or whether, depending on climate trends, there are delays in premium adjustments. Full article

The increasing frequency of extreme weather events, exacerbated by climate change, has caused significant physical damage to crops worldwide. This study explores the potential of repurposing crop plants that exhibit structural breakage due to hailstorms and strong winds and were originally cultivated for seed production (amaranth, borage, camelina, flax, quinoa, soybean, and white lupin) as alternative forages for ruminants. Their nutritional value was assessed by analyzing chemical composition, in vitro dry matter degradability (DMD), in vitro neutral detergent fiber degradability (NDFD), estimated dry matter intake (DMI), and relative feed value (RFV) compared to conventional forages (alfalfa and ryegrass hay from undamaged plant). Results revealed significant variability among the damaged crops. Borage, amaranth, and white lupin exhibited superior DMD, NDFD, estimated DMI, and RFV, positioning them as promising forage alternatives. Soybean and quinoa showed protein content, DMD, NDFD, estimated DMI, and RFV comparable to alfalfa hay, suggesting their suitability as substitutes. However, camelina exhibited limited NDFD, while flax had low DMD, NDFD, estimated DMI, and RFV, indicating the need for pre-treatment strategies to optimize their nutritional value. Overall, repurposing weather-damaged borage, amaranth, white lupin, soybean, and quinoa as alternative forages for ruminants provides a promising approach to mitigating feed shortages, improving feed resource utilization, and optimizing resource utilization in livestock production. Full article

Anti-hail nets have been employed in viticulture to reduce the damage caused by hailstorms, but whether this strategy may have detrimental effects on grape quality in the Mediterranean region is still unknown. This study was carried out in the Salento region during the 2023 harvest to evaluate the grape microclimate and fruit quality attributes of ‘Fiano’ white grapes grown uncovered or covered with either crystal or black nets. The nets had a small but significant effect on the air temperature (about 0.3 °C and 0.1 °C higher with black and crystal nets, respectively) and relative humidity (about 1% lower with both black and crystal nets) in the grape zone. However, no significant variation was recorded for grape colouration (except for the chromaticity coordinate a*) nor for the main skin photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoids), the total polyphenolic content, and the total soluble solids. Our preliminary results suggest that anti-hail nets can be effective to protect the grapevines against hailstorms and other adverse weather conditions, without having negative impacts on the colour development and bioactive compounds of white grapes in the Mediterranean region. Full article

Winter oilseed rape (Brassica napus L.), Europe’s foremost oilseed crop, is significantly impacted by hailstorms, leading to substantial yield reductions that are difficult to predict and measure using conventional methods. This research aimed to assess the effectiveness of photosynthetic efficiency analysis for predicting yield loss in winter rapeseed subjected to hail exposure. The aim was to pinpoint the chlorophyll fluorescence parameters most affected by hail stress and identify those that could act as non-invasive biomarkers of yield loss. The study was conducted in partially controlled conditions (greenhouse). Stress was induced in the plants by firing plastic balls with a 6 mm diameter at them using a pneumatic device, which launched the projectiles at speeds of several tens of meters per second. Measurements of both continuous-excitation and pulse-modulated-amplitude chlorophyll fluorescence were engaged to highlight the sensitivity of the induction curve and related parameters to hail stress. Our research uncovered that some parameters such as F_s, F_m’, Φ_PSII, ETR, F_o, F_v/F_m, and F_v/F_o measured eight days after the application of stress had a strong correlation with final yield, thus laying the groundwork for the creation of new practical protocols in agriculture and the insurance industry to accurately forecast damage to rapeseed crops due to hail stress. Full article

This paper presents a comprehensive comparative study of the resilience of leading edge anti-icing systems on business jets when exposed to severe hailstorm conditions. Using advanced simulation models correlated with experimental data, the study aims to determine the overall effectiveness of these systems when exposed to the adverse effects of hail impact. Key aspects of the study include the examination of system structural response to varying sizes and densities of hailstones, and the impact on the leading edge structural integrity and on the overall aircraft safety. The simulations are designed to replicate realistic hailstorm scenarios, considering factors such as hailstone velocity, size, and impact angle. Results from the study reveal significant differences in the performance of piccolo-tube anti-icing system under hailstorm conditions. The study assesses the operational limitations and the energy absorption of a business jet anti icing system, providing valuable insights for anti-icing robust design in this category. Full article

In recent years, severe hailstorms have caused damage to cotton leaves and stalks. In order to identify the effects of cotton leaf damage on its dry matter accumulation, protective enzyme activity and yield in different periods, in this experiment, different intensities of hail were simulated by manual leaf cutting. In this study, the effects of leaf damage on dry matter accumulation, chlorophyll fluorescence, POD (peroxidase), SOD (superoxide dismutase) and MDA levels (malondialdehyde), and yield of cotton were studied in field experiments at three stages (bud, full bud and flower boll stages) and in sub-plots with different artificial defoliation intensities (0%, 25%, 50%, 75% and 100%). Removing the leaf sources had differently sized effects on the “sink” at each stage, and these are ordered as follows: flowering and boll stage > full bud stage > pregnancy stage. The greater the intensity of leaf removal, the greater the impact on the “sink”. Among them, after removing 50% of the leaves at the full bud stage, the total dry matter of the cotton plant increased by 12.46% compared to that of the control, and the boll formation rate per plant increased by 14.99%, resulting in overcompensation. Mo, Vj and φDo all showed a tendency to decrease and then increase with the increase in defoliation intensity at different periods of the treatment, and the lowest values of Mo, Vj and φDo, and the largest values of φpo, ψo and φEo were found in the 50% defoliation treatment at the gestational bud stage. The values of ψo and φEo were at the maximum in the 25% defoliation treatment at the full bud stage. The values of Mo and Vj in the different defoliation treatments at the bolling stage showed a tendency to increase and then decrease with the increase in defoliation intensity, with the highest values in the 25% treatment and the smallest values of φpo, ψo and φEo in the 25% defoliation treatment. The POD enzyme activity level was elevated in the defoliation treatments at the three different periods, and the highest value was observed in the 50% defoliation group at the full bud and boll stages, which is a reflection of supercompensation. The SOD enzyme activity level tended to increase with the intensity of defoliation, and defoliation at the gestational and full bud stages first enhanced and then weakened the stress on the cotton plants. The differences between treatments decreased after 12 weeks. The stress of defoliation on cotton plants was weakened at the boll stage. With the increase in defoliation intensity, the content of MDA showed a gradual increasing trend. The cotton MDA content was higher than that of the other treatments at 75% defoliation at both the post-fertilized bud and full bud stage. Full article

Three facts characterise the hailstorm of 30 August 2022 in the Catalan village of La Bisbal d’Empordà and its surroundings: first, the most dramatic, the death of a child hit by a hailstone; second, the damage to most of the roofs and cars in the town; finally, the highest recorded amount of hail (more than 10 cm) in Catalonia in at least the last 30 years. This research focuses on the radar field comparison and the observations provided by an electronic survey of the study area. The results reveal that weather radar underestimated the hail size because of different factors. Conversely, some reporters provided an inaccurate hour. The difference of three months between the hail event and the electronic survey is the probable cause of this mistake in the time estimation. However, the survey delay helped to avoid answers with larger hail sizes than those provided by the official spotters. Full article

On the evening of 30 April 2021, a severe hailstorm swept across eastern China, causing catastrophic gale and damaging hailstones. This hailstorm event was directly caused by two mesoscale convective systems associated with strong squall lines, with mid-level cold advection from the northeast cold vortex, and strong low-level convergence associated with the low-level vortex and wind shear line. Double nesting of the high-resolution weather research and forecasting model (9–1 km) is utilized to simulate this hailstorm with five microphysics schemes. The radar-based maximum estimated size of hail (MESH) algorithm, differential reflectivity and fractions skill scores were used to quantitatively evaluate the precision. All schemes basically captured the two squall lines that swept through eastern China, although they appeared one or two hours earlier than observation. Particularly, Goddard and Thompson performed better in the MESH swath and fractions skill scores among the five different schemes. However, Thompson most realistically captured the reflectivity pattern, intensity and vertical structure of mesoscale convective systems. Its high-reflectivity column corresponded to the maximum center of the hail mixing ratio within the updraft region, which is consistent with the characteristics of a pulse-type hailstorm in its mature phase. Full article

Severe hailstorms frequently occurred in Beijing between May and August 2021, leading to extensive hail damage. These hailstorms were observed by radar and satellite data, and reported by surface observers. In this study, the spectral and cloud microphysical characteristics of typical Beijing events in 2021 were analyzed using Himawari-8 satellite products and ground-based S-band weather radar data obtained from the Beijing Meteorological Bureau. The relationship between Himawari-8 brightness temperature differences (BTD) and radar reflectivity was also investigated. The results revealed that the significant spectral depression of brightness temperatures (BTs) in hail clouds was observed by a satellite. Furthermore, the stronger the radar reflectivity was, the more rapidly BTD decreased, with a nonlinear relationship between them. The results of cloud physical characteristics show that, for cloud-top heights above 10 km, the cloud effective radius was about 25 μm, with a cloud-top temperature of 225 K during these hail events. By means of Gaussian fitting, the BT threshold value (11.2 μm) was determined by satellite at 230 K, with a BTD focused on 1.9 K when hailstorms occurred. These results will help us better understand the characteristics of hailstorms, while also providing information for future hail suppression in Beijing. Full article

In recent years, new approaches to intensive blueberry (Vaccinium corymbosum L.) production have become necessary, in terms of protected environments and planting systems. These are designed to avoid numerous production difficulties, such as market saturation, damage from hailstorms, bird attacks, and spring frosts, and specific soil property requirements. Use of high tunnels and planting in a custom substrate (e.g., pots, along ridges) have gained interest among growers in recent years. As in our previous study, we determined the performance of three blueberry cultivars, ‘Duke’, ‘Aurora’, and ‘Brigitta’, when planted in pots and along a ridge under a high tunnel. Substrate water content was maintained at the same level for the pots and the ridge, although the substrate temperature fluctuations were greater for pots. Plant growth in pots was significantly lower for ‘Duke’ and ‘Aurora’ compared to the ridge. Additionally, for ‘Aurora’, the fruit yield was significantly lower for pots (103.4 g/plant), compared to the ridge (315.2 g/plant), although the opposite was seen for ‘Brigitta’ (122.4 vs. 93.5 g/plant, respectively). Individual sugar and organic acid contents mostly coincided with total contents, with lower total sugars for ‘Duke’ and higher total organic acids for ‘Aurora’ and ‘Brigitta’ for pots. For ‘Duke’ and ‘Brigitta’ fruit, the contents of some individual phenolics showed significant differences between treatments for phenolic acids and flavonols. These data show that growth in pots can be a useful planting method for the blueberry cultivars ‘Duke’ and ‘Brigitta’, and high yields and good fruit quality can be attained by following correct technological measures. Full article