The heart of hurricane season is here, and the tropics are certainly alive. Three systems of interest are moving across the open waters of the Atlantic. Fizzling Tropical Depression Fiona and budding Tropical Storm Gaston are of little concern, but a much weaker undeveloped tropical "something" - presently referred as Invest 99 by the meteorological community - is creating quite a stir on social media.
A map or image of a hurricane hitting Florida that is shared on social media at this point is likely not a credible forecast. It’s important to remember the difference between one model solution (of literally dozens) versus a forecast composed with skill and from study of all possible scenarios.
Here’s a quick breakdown on all three systems...
First up is Fiona, which was downgraded to a tropical depression Monday. The former tropical storm is expected to gradually dissipate as it moves south of Bermuda by Thursday. Fiona poses no serious threat to land.
Next is newly-formed Tropical Storm Gaston, the season’s seventh named storm. As of Tuesday morning, Gaston was located 550 miles west of the Cabo Verde Islands and expected to strengthen into a hurricane by Wednesday. Gaston is also likely to turn northwest and poses no threat to land.
Finally, the system we know the least about is Invest 99. It just so happens to be the only one of the three that could impact the United States. Yes, there is a chance Invest 99 could develop and approach Florida, but it’s literally is a “coin flip” at this point. Potential outcomes range from a formidable tropical storm or hurricane turning west and hitting Florida to nothing more than a tropical wave getting pulled out to sea. Timing on this could range anywhere from Saturday to Wednesday or next week.
Models have been mystified on whether Invest 99 can even develop into a tropical cyclone. Similar to Tropical Storm Erika in 2015, the circulation may be disrupted by the mountainous terrain of the islands that make up the Greater Antilles. Even if Invest 99 does develop, dry air and wind shear are forecast to be present near or north of the Bahamas, which would further inhibit strengthening. However, some of the reliable forecast models have more recently suggested conditions would become more favorable for development in these areas if Invest 99 were to slow down.
All Floridians and those with interests up and down the East Coast of the United States are encouraged to stay informed of future official forecasts related to the tropics, and in particular Invest 99.