The biggest impact from Nepartak will be heavy rainfall, focused mainly north of Tokyo and close to the coast. The storm is swirling north extreme tropical moisture, with PWATs, or precipitable water, in excess of 3 inches. That means that every column of atmosphere contains enough water to drop three inches of rainfall — and that is an air mass that will be continually replenished as a conveyor belt of moisture feeds into the system.

Source: Washington Post July 26, 2021 15:09 UTC