It’s not uncommon for tropical systems to spin up quickly, in very close proximity to land. In this case, watches or warnings may need to be issued ahead of potential impacts in a timely manner, so that’s when a system is dubbed a potential tropical cyclone (PTC).

The National Hurricane Center began using this designation in 2017 to give forecasters the ability to issue watches and warnings earlier, before a storm technically forms. It allows for more lead time to prepare, especially when a developing system is close to land and could bring tropical storm or hurricane conditions within 48 hours.

The key difference between a potential tropical cyclone and a regular tropical disturbance is confidence in future development and impact. A PTC may not yet have a closed circulation, but computer models and satellite data strongly suggest it’s organizing. In this case, it could soon bring damaging winds, heavy rain or storm surge to land areas.

Weather in your inbox

Forecast Location

Sign Up

By signing up you agree to the Terms & Privacy Policy. Unsubscribe at any time.

Once the system meets the criteria for a tropical depression, it will be given a number, or a name if it becomes a tropical storm.

Thanks to the PTC designation, emergency managers and coastal communities don’t have to wait for that official upgrade to start preparing. The PTC essentially buys time and increases safety when minutes and hours matter most.

Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.