Читать книгу Canyoning in the Alps. Graded routes in Northern Italy and Ticino, Austria, Slovenia and the Valais Alps онлайн

33 страница из 80

Rainfall

Significant rainfall is brought about by frontal systems and afternoon storms. Fronts may bring prolonged periods of rain to large areas of the Alps, whereas afternoon storms are short-lived and very localised, but frequently severe. The latter are brought about by cumulonimbus clouds, which develop from ordinary cumulus clouds as moist air rises throughout the day, a process accelerated by high temperatures and mountain relief. These storms are more common in northern Italy and Ticino than anywhere else in the Alps, owing to the moist, warm Mediterranean air travelling up from the south. Unlike fronts, which are easy to predict, forecasting afternoon storms is difficult. It is therefore vital to get frequent weather updates and to keep an eye out for cumulonimbus development. Weather reports are available in tourist information offices, campsites and local newspapers. Relevant websites are given in each chapter.

Floods can make a huge difference to the condition of a canyoning route (left: before flooding, right: after flooding)