English: Within the span of a week, powerful back-to-back typhoons pummeled the Philippines in October. First, Typhoon Sarika made landfall over Luzon on October 15, 2016. Then Typhoon Haima hit the island four days later.

Before Haima made landfall in northern Luzon, soils were already saturated by the deluge previously delivered by Typhoon Sarika. This map illustrates the scenario, depicting satellite-based measurements of rainfall from October 14-17, 2016. Sarika’s storm track is overlaid on the map. The rainfall totals are regional, remotely-sensed estimates, and local amounts can be significantly higher when measured from the ground. According to news reports, some towns saw about 550 millimeters (22 inches) of rain on October 14 and 15.

“It’s likely that Haima will cause slides in both the Philippines and China,” said Thomas Stanley, a geoscientist at NASA’s Goddard Space Flight Center who catalogs rainfall-triggered landslides. He points out that a number of landslides, presumably due to Sarika, have already been reported, including a deadly event in southwestern Luzon.