Seasonality Of Vertical Structure In Radar-Observed Precipitation Over Southern Switzerland
Rudolph, James V 1 ; Friedrich, Katja 2
1 Univeristy of Colorado - ATOC
2 University of Colorado - ATOC
Operational radar data reveals that precipitation systems occurring on the southern side of the Alps near Locarno, Switzerland follow seasonal patterns of vertical structure. Storms occurring in summer are more convective than winter season storms as indicated by more frequent observation of reflectivity at higher altitudes during summer. Individual precipitation events occurring year-round are classified by comparison to average seasonal vertical structure. Seasonal classification of individual storms reveals a transition between winter and summer-type storms during spring and fall that follows changes in average daily surface temperature. In addition to distinct vertical structure, summer and winter-type storms have differences in duration, intensity, and interval between storms. Although summer and winter-type storms result in similar amounts of total precipitation, summer-type storms have shorter duration, and therefore greater intensity. The dependence of storm type on temperature has implications for intensification of the hydrologic cycle due to climate change. Warmer winter, spring, or fall surface temperatures may affect average precipitation intensity by increasing the number of days per year that experience more intense convective precipitation while decreasing the probability of less intense stratiform precipitation.