It is fitting that an Atlantic hurricane which shares its name with our director of hydrology should be noted for its particular hydrological impact. The most serious impact from Hurricane Harvey has been the extreme rainfall which has now amounted to over 1000mm in the four days from 25-28th August. By contrast the average annual total at our office location in Oxfordshire, UK, is 611mm. The rainfall associated with Hurricane Harvey has been described as unprecedented although tropical cyclones have produced similar amounts of rainfall in other parts of the world. For example, Hurricane Mitch brought moist air from the Pacific over Central America in October 1998 and 928mm was recorded over 5 days with unofficial estimates of 1,900mm. Typhoon Nina which hit China in August 1975 reportedly brought over 1000mm of rainfall in 24 hours and led to the failure of 62 dams. This PDF has more detail on the impact of the flooding including a map showing potential flood extents. Hurricane Harvey
