Tornadoes in Lithuania in the period of 1950–2002 including analysis of the strongest tornado of 29 May 1981

Abstract

Lithuania is a small European country situated on the eastern coast of the Baltic Sea. The main “weather factory” in these middle latitudes is the Atlantic Ocean. On the other hand, being close to continental weather conditions in the east, Lithuania encounters a variety of weather patterns. According to the data of Lithuanian Hydrometeorological Service, there were 23 tornadoes recorded in Lithuania in the period of 1950–2002. It has been established that tornadoes occur mostly in the warm period of the year—in spring and summer. The afternoon, between 12 and 15 UTC, is the most favorable part of the day for tornadoes to occur. Synoptic situation of the very strongest tornado (F2 on the Fujita Scale) of 29 May 1981 in the eastern part of the country was typical for most of the tornadoes there. A cold front was moving from the southwest of Lithuania to the northeast alongside a low, passing in parallel to the upper level flow. A closed surface low developed along the front. Convergence at the surface level, associated with divergence at higher levels, was the main cause of upward vertical motion. The powerful storm formed over the Eastern Lithuania at the point of coincidence of the wet bulb maximum potential temperature and the strongest convergence. Unfortunately, there was no good proximity sounding to the tornado. The Kaunas upper air station's data did not fully represent the convection process, as Kaunas was already in the cold air mass when the tornado developed in the warm air, so the Minsk (Belarus) data was analyzed in addition and compared to the Kaunas soundings. The analysis of tornadoes in Lithuania shows their initiation conditions to be similar to those in the rest of Europe and the USA.