Okresy bez opadów i ze słabymi opadami w polskich Karpatach (1984-2013)

Abstract

This paper describes the sequences of days without any precipitation as well as those with small precipitation consid-ering their circulation determinants. The frequency of the dry spells identified with the method developed by Koźmiński (1986) and Konopko (1988) was also examined. The sequenc-es of days without any precipitation or with small precipitation were determined based on the daily sums of precipitation over 30 years, i.e. within the years 1984–2013 from 49 measuring stations located in Polish Carpathian Mountains. The data of daily precipitation sums were obtained from the IMGW-PIB. In the study area the highest average number of days without any precipitation – over 200 days was in Świdnik-Tęgoborze– 214 days, and the lowest in Wisła-Malinka – 157 days. Most of the cases without precipitation were as single days and the number of these days in all measuring stations during analysing period exceeded 550 days. The longest, forty-day, period of sequential days without precipitation was noticed in Cisna (29 IV–7 VI 1991) and in Szczyrk (21 X–29 XI 2011). In every year according to Koźmiński’s method (1986) in the area of Polish Carpathian Mountains there occurred on aver-age 2–3 dry spells lasting 11–15 days, 1–2 dry spells lasting 16–20 days. On the other hand, on average 1 dry spell last-ing over 20 days took place in all measuring stations, except in the measuring stations located in the catchment of Small Vistula and Sola River. In analysing period it was not certi-fied the significant changes number of dry spells independently of their duration. In the study area, the longest period without precipitation or low precipitation was regarded to anticyclonic circulation types – southern (Sa), western (Wa) as well as the anticyclonic wedge (Ka) type.