Portal:Tropical cyclones/Anniversaries/April/20

April 20
 * 1997 - Typhoon Isa reached its peak intensity with winds of 270 km/h (165 mph) to the west of the Mariana Islands. Isa passed south of Guam, where it caused beneficial rainfall.
 * 2017 - Tropical Storm Arlene intensifies from a subtropical depression, making it one of only two systems in the Atlantic to form in the month of April.