Corporal-Lodangco IL and Leslie LM
This study aims at providing an increased understanding of tropical cyclone (TC) activity in the Philippines, to assist in reducing the fatalities and economic costs of TC impacts. A cluster analysis, using K-means, is applied to Philippine region TCs for the period 1950-2011. The clustering is carried out for TC genesis and decay locations, and TC tracks. Silhouette coefficient values and key meteorological and oceanic variables determine the optimal cluster numbers. It is found that, for the Philippine region, there are 4 genesis location, 5 decay location and 6 track clusters. The classification of TC genesis locations captures the longitudinal separation of cyclogenesis regions. The formation area east of the Philippines (west of 140°E) is the most active region, with 398 genesis points. The main TC dissipation area is Southeast Asia, with 352 decay points. Clustering the TC tracks identifies various track types by separating them into discrete patterns. Several distinct types of straight moving and recurving trajectories emerge. Short, straight west northwestward tracks directed towards Indochina have the highest trajectory frequency, with 248 TC tracks. The spatial and temporal behavior of Philippine TCs is determined from the clusters of genesis locations, decay locations, and tracks, for specific months. Because the TC genesis locations define the subsequent TC paths and landfall locations, they consequently also provide valuable TC forecasting guidance. Moreover, the monthly distribution of genesis and decay locations, and tracks, enables the variability of seasonal cycles between the clusters to be calculated.