Abstract
This paper presents a synoptic classification of cold fronts over the east of Santa Catarina (SC) state, in order to identify the main synoptic patterns associated with extreme rainfall over Itajaí Valley region. To this purpose, the Principal Component Analysis technique was applied to the Climate Forecast System Reanalysis (CFSR) (NCEP) for the period 1979-2010. Previously, it was carried out a climatology of cold fronts over the east of SC, whose main results show a higher frequency of fronts associated with extreme rainfall over Itajaí Valley during spring. The results provide five main synoptic patterns that are representative of about 83.4% of all the cases of cold fronts with extreme rainfall over the Itajaí Valley region. The most frequent synoptic pattern shows an intense southeast quadrant flow over the studied area, determined by the presence of a strong post-frontal anticyclone observed over southern Buenos Aires state, whose cold front associated is in the extreme northeastern part of the SC state. Finally, there are two summer typical synoptic patterns related to extreme rainfall in the Itajaí Valley region; one related to the South Atlantic Convergence Zone (SACZ) episodes and another associated with the Chaco Low (CHL).
Keywords:
fronts classification; principal components; extremes rainfall
