Climatological analysis of precipitation on Mount Baldo (Italian Alps). Part II: precipitation spatial distribution and relationship with circulation types.
The spatial distributions of the average annual and seasonal rainfall on Mount Baldo massif, an interesting representative area in the south-eastern part of the Italian Alps, was built and compared to existing datasets. Precipitation was then related to the meteorological configuration, understood as the prevailing direction of the large-scale wind over the Alps. Particular attention was paid to the vertical precipitation gradient, which is necessary to extrapolate data at higher altitudes, where no stations are available. Using the KED (Kriging with External Drift) interpolation method with elevation and geographic coordinates as auxiliary variables, spatial maps of annual and seasonal precipitation were built. Many daily indexes such as total rainfall, precipitation contribution, wet days frequency, percentage of wet days, mean conditioned precipitation and number of days with heavy rainfall were therefore calculated for the 5-year period 1968-1972, correlated to 8 different weather types and finally spatialized, discovering the influence of Mount Baldo on the spatial distribution of precipitation for different large-scale weather configurations. SW and S flows are the wettest and the northern ones (N, NE, NW) the driest for our target area; an important Stau - Foehn phenomenon with various weather types was found and precipitation nature and its contribution to total rainfall in different seasons were investigated