Nolo has had quite a week. After weakening to a tropical storm, it remains active and is forecast to cross the International Date Line this weekend. When it does, it won't get a brand-new name — it will simply become Typhoon Nolo.

Typhoons are what hurricanes are called in the Western Pacific basin.

Whether a storm is called a hurricane or a typhoon depends entirely on geography, not its physical structure.

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Sitting at 180 degrees longitude, the International Date Line marks the boundary between the Central Pacific basin and the Western Pacific basin.

Crossing that line from east to west — or vice versa — automatically changes a storm's official title on the map while leaving its assigned name completely intact.

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What actually happens:

• Classification changes: Nolo shifts from "hurricane" to "typhoon" purely because of its geographical position relative to the International Date Line. If sustained winds top 150 mph, it would even be designated a Super Typhoon.
• The name never changes: Under World Meteorological Organization rules, Nolo keeps its assigned name regardless of which basin it enters. There is no renaming involved — just a regional change in terminology for the exact same storm system.
• Forecasting duties shift: Official tracking responsibility transfers from the Central Pacific Hurricane Center to the Japan Meteorological Agency and the Joint Typhoon Warning Center, as forecasting authorities are assigned by basin boundaries.
• Wind speeds dictate the title: To be called a typhoon, the storm must maintain sustained winds of at least 74 mph. If Nolo remains below that threshold when crossing, it will simply be classified as Tropical Storm Nolo.

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This isn't new or unprecedented. We've seen storms transition from hurricanes to typhoons before.

Hurricane Ioke became Typhoon Ioke in 2006, Hurricane Genevieve did the same in 2014, and most recently, Hurricane Dora crossed the International Date Line in August 2023 to become Typhoon Dora.

Faiza Mohammed is a meteorologist intern at weather.com. She studied geography and worked with the Weather Dawgs team at the University of Georgia. She also received her master's in Earth and Atmospheric Sciences from the Georgia Institute of Technology.