The purpose of this research is to identify changes in the spatiotemporal distribution and severity of meteorological droughts in Ukraine between 1946 and 2020. In order to determine the role of precipitation and atmospheric evaporative demand on drought severity, two drought indices were applied for comparative analysis: the standardized precipitation index (SPI) and the standardized evaporation precipitation index (SPEI). Both indices were calculated on 3‐ and 12‐month timescales. The gridded dataset of monthly air temperature and atmospheric precipitation for Ukraine with high spatial resolution (0.1° × 0.1°), developed in the Ukrainian Hydrometeorological Institute, was used. Results of time series analysis of drought indices showed at least 20 episodes, in which more than 25% of the territory of Ukraine was affected by drought of varying intensity. Trends show an increase in drought severity determined mostly by a strong observed increase in the atmospheric evaporative demand. Tendencies towards an increase in the duration and intensity of droughts were observed mainly in the southwestern, central and northern regions of Ukraine. The main cause of the increase was droughts in spring and summer. The temporal analysis of the spatial distribution of areas affected by drought during the identified main drought episodes showed different patterns in drought propagation across the territory of Ukraine.

The features of regional atmosphere circulation, which are accompanied simultaneously by two high impact hydrometeorological phenomena (such as droughts and dry winds) in the Black Sea Steppe zone of Ukraine were considered. Dry wind as a complex phenomenon is widespread throughout Ukraine during the warm season of the year. Dry winds often accompany a drought, but they appear as peripheral processes in contrast to the droughts, which are usually formed in the central parts of anticyclones. The number of days with dry winds at the Steppe stations varies on average from 10 to 20 cases to 40–50 cases per warm season, while in the coastal zone the number of days decreases sharply due to a common increase of air atmospheric relative humidity. Analysis of the interannual dynamics of dry winds showed that the number of days with dry winds increases significantly in seasons characterized by a high aridity, according to values of the drought index used. Two time intervals with high and low frequency of seasonal droughts and dry winds were detected during the considered period: 1995–2015. These phenomena have become more intense after 2004, compared to the previous decade. Backward trajectories of air particles showed that the most cases of dry winds originate in air masses, which form up to 5 days previously at the surface level to the east or north-east outside of the territory of Ukraine and then pass into the study area within 5 days.

The regional features of the spatial distribution of extensive severe atmospheric droughts during the vegetation season in the south of the East European Plain at the beginning of the 21st century were studied according to the data on the Palmer Drought Severity Index. The circulation conditions for the formation of droughts were analyzed, and the characteristics and some regularities of blocking episodes were revealed. It was shown that the boundaries of severe droughts are in good agreement with the domains of negative extremes of the satellite vegetation index, which are observed in July and August.

The summer of 2022 was very dry across Missouri and the surrounding regions including much of the Great Lakes, Midwest, and southern plains of the USA. A comparison of this summer to the dry summer of 2012 and the relatively wet summers of 2018 and 2021 was carried out using the National Centers for Environmental Prediction/National Centers for Atmospheric Research reanalysis, the Climate Prediction Center teleconnection indexes, and the blocking archive at the University of Missouri. The summer of 2022 was like that of 2012 which was characterized by a strong 500 hPa height anomaly centered over the western US and plains as well as very little blocking in the East Pacific. The summers of 2018 and 2021 were characterized by more zonal flow over the USA and more blocking in the East Pacific, similarly to the results of an earlier study. The teleconnection indexes for the prior spring and summer were largely similar for the two drier years and opposite for the wetter years. The surface conditions for the drier years were more similar while these were opposite for the wetter years. The integrated enstrophy (IE) used in earlier studies identified a change in the large-scale flow regime in early June 2022, which coincided with a decrease in the precipitation over the study region. However, one key difference was that the spring of 2022 was characterized by blocking more consistent with a wetter summer. This would have made the predictability of the drought of summer 2022 less certain.

The character of the atmospheric general circulation during summer-season droughts over Eastern Europe/Western Russia and North America during the late twentieth and early twenty first century is examined here. A criterion to examine atmospheric drought events that encompassed the summer season (an important part of the growing season) was used to determine which years were driest, using precipitation, evaporation, and areal coverage. The relationship between drought and the character of the atmosphere, using the Dzerzeevsky weather and climatic classification scheme, atmospheric blocking, teleconnections, and information entropy, was used to study the atmospheric dynamics. The National Centers for Environmental Prediction (NCEP) re-analyses dataset archived at the National Center for Atmospheric Research (NCAR) in Boulder, CO, USA, is used to examine the synoptic character and calculate the dynamic quantities for these dry events. The results demonstrate that extreme droughts over North America are associated with a long warm and dry period of weather and the development of a moderate ridge over the Central USA driven by surface processes. These were more common in the late 20th century. Extreme droughts over Eastern Europe and Western Russia are driven by the occurrence of prolonged blocking episodes, as well as surface processes, and have become more common during the 21st century.

In the Mediterranean and occasionally in the Black Sea, low-pressure systems with the character of both mid-latitude and tropical cyclones can form. These hybrid storms are called subtropical storms, subtropical depressions, medistorms/medicanes, or tropical-like cyclones (TLC). A strong low-pressure system given the name Falchion developed in northern part of the Black Sea during 11–20 August 2021. This storm was blamed for damage and more than 30 casualties in the nations bordering the region. At peak intensity, this storm was a as strong as a tropical depression. Falchion developed and moved northeast, reaching peak intensity before becoming nearly stationary. The NCEP reanalyses and satellite data obtained from Eumetsat’s geostationary satellite, Meteosat-8, were used to examine the character of the storm. This study demonstrates that the movement of Falchion was impeded by a blocking event that occurred over central Asia during much of August 2021. The storm did share characteristics with tropical systems, but a comparison of Falchion to tropical depressions and subtropical storms in the North and South Atlantic demonstrated that this storm was more consistent with these types of storms when examining the storm and the proximal environment. This included an examination of integrated water vapor (IVT) plumes, and the plume associated with Falchion did rise to the character of an atmospheric river in spite of the smaller scale.