Читать книгу Walking in Bulgaria's National Parks. Pirin, Rila and Central Balkans National Parks онлайн

40 страница из 63

At lower altitudes, the average annual precipitation within the Central Balkan national park varies from 550mm to 1000mm, with the southern slopes being notably drier than those to the north. At altitudes above 1000m, the average annual precipitation reaches 1200mm, and at hizha Ambaritsa on the northern flank of the range it is 1360mm, making this one of the wettest places in Bulgaria. Maximum precipitation occurs in early summer (typically during June) and is lowest in winter (usually in February).

During winter, precipitation tends to fall as snow. The first fleeting flurries can often be seen in September or October, but it is not usually until November that any dusting of snow is likely to remain permanent. The snow cover then gradually accumulates over the ensuing months, in March reaching a maximum depth of between 150cm and 220cm at altitudes above 2000m. At higher altitudes, the snow cover tends to last between 150 to 180 days, while in lower parts of the national park the duration is typically 75 to 80 days. Avalanches are a serious menace in the region during the winter months, typically in the high mountain treeless zone between 1500m and 2200m.