Typhoon Maysak, known in the Philippines as Typhoon Chedeng, was the most powerful pre-April tropical cyclone on record in the Northwestern Pacific Ocean. The fourth named storm of the 2015 Pacific typhoon season, Maysak originated as a tropical depression on March 26. The next day, the Japan Meteorological Agency (JMA) upgraded the depression to a tropical storm and assigned it the name "Maysak". According to the JMA, Maysak became the second typhoon of the year on March 28. The typhoon explosively intensified into a Category 5 super typhoon on March 31, passing near the islands of Chuuk and Yap in the Federated States of Micronesia. After maintaining that intensity for 18 hours, Maysak weakened, made landfall over the Philippine island of Luzon as a minimal tropical storm, and dissipated shortly afterwards.