Heavy precipitation events in Lithuania for the period 1961–2008 were analysed. The spatial distribution and dynamics of precipitation extremes were investigated. Positive tendencies and in some cases statistically significant trends were determined for the whole of Lithuania.Atmospheric circulation processes were derived using Hess & Brezowski’s classification of macrocirculation forms. More than one third of heavy precipitation events (37%) were observed when the atmospheric circulation was zonal. The location of the central part of a cyclone (WZ weather condition subtype) over Lithuania is the most common synoptic situation (27%) during heavy precipitation events.Climatic projections according to outputs of the CCLM model are also presented in this research. The analysis shows that the recurrence of heavy precipitation events in the 21st century will increase significantly (by up to 22%) in Lithuania

The aim of this research is to analyse and project the effects of changing climate on Lithuanian river runoff and water temperature. Climate change is expected to affect the extremes of the major river indices that impact fundamental ecological processes in river ecosystems. The available runoff and temperature data of rivers from three different hydrological regions of Lithuania were used. HBV software was applied for modelling of hydrological processes in the selected river catchments. The expected future changes of runoff and water temperature were projected according to a new set of scenarios (called representative concentration pathways) presented in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The projected extreme values of runoff (flood and low flow discharges) and water temperatures in the beginning and the end of the 21st century were compared to the ones from the past period. The results showed a decrease of spring flood discharges and summer low flows and an increase of river water temperature at the end of the 21st century. The results are going to be used for an integrated assessment of the impact of climate change on aquatic animal diversity and productivity.

The dynamics in dryness over the Baltic Sea region during the observation period of 1960–2009, as well as the climate prediction for the 21st century have been evaluated in this research. The dryness of the investigated area has been examined using the Standardized Precipitation Index (SPI). The precipitation amount data provided by the Climate Research Unit (CRU) at the University of East Anglia have been used in this study. Projections of future dryness changes are based on the output data of the regional CCLM model driven by A1B and B1 emission scenarios. The increase of SPI values, i.e. a decline in dryness, have been found over the last fifty years in the major part of the investigated area. However, the probability of short-term droughts remain high against the background of a general decrease in dryness. The increased dryness during the analyzed period has been found only in the southern part of the Baltic Sea region. Similar changes are also foreseen for the 21st century. The dryness is expected to increase in the south (especially in summer), while the central and northern parts of the region are likely to witness the recurrence of a drought decrease.

The primary objective of this study was the evaluation of runoff regime changes over the last 50 years in Lithuanian rivers. These changes were compared with the Neman river runoff regime changes in 1812–2009. On the basis of daily water discharge data, trends in the annual, maximum and minimum runoff characteristics as well as changes in the seasonal pattern of runoff were estimated. Regression analysis and the Mann-Kendall test were used to determine changes in the long-term hydrological regime. The magnitude of changes was estimated using Theil-Sen estimator. 1960–2009 runoff changes in Lithuanian rivers can be related to climatic changes. Sharp increases of January and February runoff during 1960–2009 were the largest changes throughout the observation period 1812–2009. The rate off runoff decrease in April was also among the largest decreases recorded. Spring flood and cold season minimum flow dates have become earlier than used to be.