As we enter peak hurricane season, the National Hurricane Center is tracking two disturbances that could develop into tropical storms.
The NHC describes Invest 99L as “a broad low pressure system, associated with a tropical wave” that is producing a large area of showers and thunderstorms off the coast of Africa, several hundred miles south-southwest of the Cabo Verde Islands (formerly known as Cape Verde).
Invest 99L will most likely form into tropical storm by early next week, the NHC says, while moving west-northwestward at about 15 mph across the tropical Atlantic. Chances of development are 50 percent over the next 48 hours and 80 percent over the next five days.
Another area of clouds and thunderstorms associated with a tropical wave, this one is over the western Caribbean and Bay of Campeche in the southeastern Gulf of Mexico.
For purposes of observation, the NHC has labeled this disturbance Invest 90L. It has a 20 percent probability over the next two days and a 60 percent probability over the next five days of developing into a tropical storm.
“Neither of them are any threat yet to the United States, so we have plenty of time to watch them,” NHC meteorologist and spokesman Dennis Feltgen said. “It's a great reminder for everybody that lives along the coastline and inland too that we are in the hurricane season and we're going into the heart of the season.”
Peak hurricane season runs from mid-August through late October. The NHC’s invest numbers run from 90-99. An invest is opened to study and track tropical systems.
Once the number 99 is used, labeling starts over with the number 90. The “L” behind the number refers to an Atlantic Ocean disturbance.
Feltgen said both systems would need to become much better defined, and at least headed for tropical storm status, before any potential tracks are forecast. A system reaches tropical storm strength when sustained winds, those lasting one minute or more, reach 39 miles per hour and blow up to 73 miles per hour.
A tropical storm becomes a hurricane when sustained winds reach 74 miles per hour.
If and when a tropical storm is designated and enters the Gulf of Mexico, Coast residents can find tracks, modeling and potential storm-surge mapping at hurricanes.gov.