Typhoon

A typhoon is a tropical cyclone — a large rotating storm system with sustained winds of at least 64 knots — occurring in the western North Pacific Ocean, generally west of the dateline and north of the equator. Typhoons develop over warm ocean waters when sea surface temperatures exceed approximately 26°C and atmospheric conditions favour the generation of organised convection. They are named and tracked by the Joint Typhoon Warning Center and regional meteorological authorities, with warnings disseminated via NAVTEX, SafetyNET, and coastal radio stations. For a master, a typhoon is one of the most severe threats to a vessel at sea. The rotating wind field can extend hundreds of miles from the centre, and the most dangerous sector — the 'dangerous semi-circle' in the northern hemisphere, right-forward of the storm track — is where wind and sea conditions are most extreme and where the ship is most at risk of being drawn into the path of the storm. Mariners apply the Rules of the Storm — manoeuvring rules developed before satellite forecasting — as a supplement to modern routing advice. Weather routing services and company procedures should be consulted when a typhoon is forecast in the vessel's area. Deck cargo must be additionally secured, watertight integrity ensured, and heavy-weather routines implemented before the storm arrives. SOLAS Regulation V/34 requires that known weather hazards be considered in the voyage plan, and a master who proceeds into a typhoon track without adequate precaution may face questions about seamanship.