Climatic characterization of foehn episodes in Piedmont, Italy

An analysis ofrhe yearly, seasonal and monrhly frequency of Norrh and Norrh-West foehn in north-western Piedmont (Italy) has been carried out considering weather stations located in rhe Susa Valley, one of the largest valleys in rhe region. The direction of foehn episodes has been performed by adopting synoptic, mesoscale and punctual reeognition criteria. The yearly, monthly and seasonal distriburions of foehn episodes have been investigated. The foehn even occurred on 16,h·18,hDecember 2005 has been selected and analyzed separately as a case representative of ali foehn cases in Susa valley. It has been verified that the comparison among the potential ternperatures measured sr a downstream station and as a referencestation representative of fhe flow at crest levei is a good indicator of foehn occurrence.