Fig. 8: Four clusters were identified using self-organizing map classification by wind speed anomaly at 850 hPa.

The composite mean of wind speed anomaly at 850 hPa (m s⁻¹, magenta contours, solid for positive and dashed for negative), potential vorticity at 850 hPa (0 PVU; black contour, negative values are to its south), and precipitation anomaly in the fifth day following t_e (mm day⁻¹, shading) for a cluster 1, b cluster 2, c cluster 3, and d cluster 4. The black rectangle in d presents the area used for clustering, and the yellow line encloses the land fraction of the target area used in Table 1.