On December 20, the Japan Meteorological Agency started to monitor a tropical depression that had formed about 1,090 km (675 mi) to the southeast of Yap Island in the Federated States of Micronesia.
[4][5] The broad and poorly organized system was being affected by moderate to high vertical wind shear, which was being offset by warm sea surface temperatures.
[6] Late on the same day, when central convection was increasing and consolidating over a defined low-level circulation center (LLCC), both the JMA and the JTWC upgraded it to a tropical storm, with the former assigning the name Nock-ten.
[7][8] One day later, late on December 22, the JMA upgraded the system to a severe tropical storm, and Nock-ten started to form an eye revealed by microwave imagery.
[9][10] Tracking west-northwestward and then westward along the southern periphery of a deep-layered subtropical ridge, Nock-ten intensified into a typhoon at noon UTC on December 23.
[14] The JTWC also upgraded Nock-ten to a Category 4-equivalent super typhoon, when the system was in an area of low vertical wind shear, excellent dual-channel outflow, and sea surface temperatures of 29 °C.
[26][27] Influenced by a Northeast Monsoon surge, the system accelerated southwestward, and convection was unable to develop over the fully exposed LLCC due to high vertical wind shear and colder dry air.
The typhoon generated huge waves between six and eight meters in height, causing the vessel to come off its mooring and drift toward Tingloy where it sank.