Częstość występowania i grubość pokrywy śnieżnej u podnóży masywu Babiej Góry w sezonach zimowych 1960/61–2014/15

The aim of the study was to further our knowledge on changes in the nival conditions prevailing in the lower part of the Babia Góra massif during winter. Data on snow cover thickness in the winter season was recorded daily in the years 1960/61 to 2014/15 by a meteorological station established by the Institute of Meteorology and Water Management – National Research Institute in Zawoja (697 m altitude). Based on the long-term measurements carried out in Zawoja, the average duration of the snow cover with a thickness of ≥ 1 cm was determined to be 104 days. Snow cover duration was subject to considerable variability ranging from only 47 days in 2013/14 to 145 days in 1993/94 and was observed to have shortened from an average of 118 days in the decade 1960/61–1969/70 to 96 days in the previous decade (2000/01–2009/10). The potential maximum duration of snow cover was 157 days on average, with the most snowy months being January and February, when a snow cover was present on 75% and 81% of all days, respectively. During these two months, also the maximum thickness was recorded reaching a maximum of 178 cm (January 30, 1976). In contrast, snow was never observed in July, August and September. The studied time period was furthermore characterized by a high variability of the winter snowiness index ranging from 1.61 in 2013/14 to 8.00 in 1962/63. In summary, a distinct periodicity (16–19 years) with regard to the number of days with snow cover, the average and total snow cover as well as the winter snowiness was observed over the examined time frame.