A hurricane is a tropical revolving storm (TRS) — an intense, rotating low-pressure weather system with sustained winds of at least 64 knots — that forms specifically over the Atlantic Ocean or northeastern Pacific Ocean.
Same Phenomenon, Different Names by Region
The term used depends purely on where the storm forms, not any meteorological difference:
- Hurricane — Atlantic Ocean, northeastern Pacific
- Typhoon — northwestern Pacific Ocean
- Cyclone — Indian Ocean, South Pacific
Formation Conditions
TRS form over warm tropical ocean waters, generally above 26-27°C, requiring sufficient distance from the equator for the Coriolis effect to initiate rotation.
Why It’s Dangerous to Ships
- Sustained winds of 64+ knots, with gusts significantly higher
- Extremely high, dangerous sea states
- The “dangerous semicircle” (right side of track in the Northern Hemisphere) where the storm’s rotational wind speed adds to its forward movement, producing the most severe conditions
Avoidance
Vessels use forecast tracking and standard avoidance rules (bringing wind onto a specific bow or quarter depending on which semicircle the vessel is in) to steer clear of a TRS’s most dangerous areas — covered in detail in the meteorology guide for seafarers.
Exam Relevance
Hurricane/TRS formation, structure, and avoidance procedures are core Meteorology topics in deck officer competency exams.