Influence of synoptic situations on the precipitation in Krakow (Poland)

The impact of the synoptic situations on the occurrence of precipitation in Krakow is analysed. Daily records of precipitation from the period 1873-1999 were used, as well as the calendar of synoptic situations by T. Niedzwiedi. The study presents annual and long-term variations of daily precipitation, frequency of the synoptic situations, and frequency of precipitation for particular situations. For the 21 types of synoptic situations, the following characteristics were defined: average daily precipitation and its effectiveness ratio, maximum precipitation and the probability of occurrence of days with or without precipitation. Most precipitation occurs during the advection of air masses from the west and during the cyclonic trough, which is related to high frequency of occurrence of such situations. From among 21 synoptic situations, the following ones are the most favourable for the development of abundant precipitation: northeastern cyclonic situation (NEc), north cyclonic situation (Nc), cyclonic trough (Bc) and centre of low pressure (Cc). Copyright (C) 2001 Royal Meteorological Society.