Based on the Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) reanalysis data from 1981 to 2020, the climatological features of the vertical components of three-dimensional Eliassen–Palm (EP) wave activity fluxes (WAF) were investigated. The parameter is related to eddy heat flux and is a key indicator of the upward and downward propagation of quasi-stationary planetary-scale waves. Northern Hemisphere data from a 30 km height (or about a 10-hPa level) were used for the analysis. We evaluated the extreme values (daily maxima and minima) of the vertical WAFs, the probability of their recurrences, and their interannual and daily variability observed over the last four decades. The correlation between the upward EP WAF maxima and the 10-hPa stratosphere temperature anomalies were examined. The results show that very close relationships exist between these two parameters with a short time lag, but the initial state of the stratosphere is a key factor in determining the strength of these relationships. Moreover, trends over the last 40 years were evaluated. In this research, we did not find any significant changes in the extreme values of the vertical WAFs. Finally, the dominant spatial patterns of upward and downward extreme WAFs were evaluated. The results show that there are three main regions in the stratosphere where extremely intensive upward and downward WAFs can be observed.

This study investigates the impact of meteorological conditions on unplanned outages of overhead transmission lines (OHTL) in Lithuania’s 0.4–35 kV power grid from January 2013 to March 2023. Data from the Lithuanian electricity distribution network operator and the Lithuanian Hydrometeorological Service were integrated to attribute outage events with weather conditions. A Bayesian change point analysis identified thresholds for these meteorological factors, indicating points at which the probability of outages increases sharply. The analysis reveals that wind gust speeds, particularly those exceeding 21 m/s, are significant predictors of increased outage rates. Precipitation also plays a critical role, with a 15-fold increase in the relative number of outages observed when 3 h accumulated rainfall exceeds 32 mm, and a more than 50-fold increase for 12 h snowfall exceeding 22 mm. This study underscores the substantial contribution of lightning discharges to the number of outages. In forested areas, the influence of meteorological conditions is more significant. Furthermore, the research emphasizes that combined meteorological factors, such as strong winds accompanied by rain or snow, significantly increase the risk of outages, particularly in these forested regions. These findings emphasize the need for enhanced infrastructure resilience and targeted preventive measures to mitigate the impact of extreme weather events on Lithuania’s power grid.

Statistical estimations of Arctic Oscillation (AO) impact on air temperature regime in the Eastern part of Baltic region are presented. The region is characterized by high inter-annual and inter-seasonal variabilities. It is important to note that in the region of global warming extremely low winter temperatures can be observed on the European territory of Russia. AO is one of large-scale global structures of atmospheric circulation closely associated with weather variability in Northern Europe. AО anomalies occur in the upper atmosphere (stratosphere) and only then transferred to tropospheric lower layers. The anomalies can be preserved during long period up to two months, so they can be predictors in long-range weather forecast. In turn, changes in stratospheric polar vortex and sudden stratospheric warmings can be related to the geomagnetic activity. Perhaps, the geomagnetic activity influences the meridional temperature gradient and then changes in the structure of the stratospheric zonal wind. In turn, the changes have an impact on the tropospheric circulation. The stratosphere–troposphere connection occurs during winter months. Therefore, the paper presents the analysis of extremely cold winter anomalies in the Eastern part of Baltic Sea region. At the same time, we considered atmospheric circulation peculiarities related to AO phase change. The analyzable time interval covers 1951–2014.

The paper presents statistical estimations of Arctic Oscillation (AO) impact on air temperature regime in the eastern part of the Baltic region. The region is characterized by high inter-annual and inter-seasonal variability. It is important to note that in the region of global warming extremely low winter temperatures can be observed on the European territory of Russia. AO is one of the large-scale global patterns of atmospheric circulation closely associated with weather variability in northern Europe. AО anomalies occur in the upper atmosphere (stratosphere) and only then are transferred to tropospheric lower layers. The anomalies can persist over a long period of time (up to two months); so they can serve as precursors in long-range weather forecasts. In turn, changes in stratospheric polar vortex and sudden stratospheric warmings can be related to geomagnetic activity. Perhaps geomagnetic activity influences the meridional temperature gradient and then changes the structure of the stratospheric zonal wind. These changes have an effect on the tropospheric circulation. The stratosphere–troposphere coupling takes place during winter months. Therefore, the paper deals with extremely cold winter anomalies in the eastern part of the Baltic Sea region. At the same time, we examine atmospheric circulation peculiarities associated with AO phase change. We analyze data for 1951–2014.

One of the most important uncertainties in a changing climate conditions are changes in climate extremes. While precipitation extremes are particularly important at low latitudes, thermal extremes are of major interest at mid-latitudes. This study analyses the cold (CS) and warm (WS) spells winter climatology in the eastern part of the Baltic Sea region from 1951 till 2020. Data from the E-OBS database were used in the research. A CS/WS in this study is an event when extreme low/high (below 10th/above 90th percentile) air temperature persists for at least 5 days. The period 1971–2000 was used as the climate norm. The results show that both absolute winter air temperature minimum and maximum increased over the investigation period. The absolute maximum of winter air temperature strongly increased after 1988, when a statistically significant regime shift was determined. The results show that the number of WSs have increased and changes are statistically significant in most cases. Meanwhile, the recurrence and duration of CSs have changed insignificantly, although the number of years with more than one CSs is decreasing. The total number of CS/WS cases per season slightly increased. Total number of WSs days increased a lot at the last decade of the investigation period, while the number of CSs days changed insignificantly in recent several decades.