Invest 91L: What is an invest, and what does it mean during hurricane season?

June 1 marked the beginning of the 2023 Atlantic Hurricane Season, which is already off to an active start with a possible tropical disturbance being monitored in the Gulf of Mexico, west of Florida.

This system, which now has a 70% chance of tropical development as of Thursday afternoon, is currently known as Invest 91L.

What is an "invest?," and what does that mean? We asked FOX 35 Chief Meteorologist Jayme King.

An invest system is short for "investigative system" or "area of interest." The invest tag is reserved for areas of disturbed weather being monitored for potential tropical development.

Once the National Hurricane Center expresses interest in a potential system, spaghetti forecast models are generated, which can help forecast where a particular system may travel.

Invests are identified by numbers ranging from 90-99, and the letter "L" is attached if the system is located in the North Atlantic. These numbers are rotated throughout the season and re-used if necessary.

This system of identification is crucial to forecasters, especially if there are multiple tropical disturbances being tracked in a particular area at the same time.