Fig. 1: Synoptic conditions of selected extreme precipitation events.

a, b correspond to the 202108 event, c, d to the 202007 event, and e, f to the 201009 event. For each event, the first row (a, c, e) depicts the surface and upper-level dynamic features, where the purple contour represents 300 hPa potential vorticity, and the shading indicates the mean sea level pressure. The second row (b, d, f) illustrates the moisture transport and mid-to lower-level features. Vectors represent integrated vapor transport (IVT), black contours indicate 850 hPa geopotential height, and green contours highlight the 5880 m geopotential height at 500 hPa, marking the extent of the Northwest Pacific Subtropical High. All panels correspond to the time of maximum observed hourly precipitation recorded at the surface stations for each event.