Predictions on how Invest 99L will affect Florida in the upcoming days

Posted at 8:05 PM, Aug 23, 2016
and last updated 2016-08-24 12:09:38-04

Here is my latest thinking on the potential tropical system we have in the Atlantic and its possible effects on Florida.

Right now the system is weak with an elongated area of low pressure near the northern end of the Lesser Antilles. A hurricane hunter aircraft went out to investigate the storm Tuesday and found only a broad, elongated circulation associated with this tropical wave. Also, thunderstorms that had formed in association with the wave have diminished through the day and overall the system looks fairly ragged.

UPDATE: Invest 99L Could Pass Through South Florida

Organization of the tropical wave will be low to occur as conditions for the next couple of days look marginal for further development. However, by later this week and this weekend as the system approaches the Bahamas, conditions will become more favorable for organization as will be moving into VERY warm water in the western Atlantic and the dry air surrounding the storm as of late should abate.

I am becoming more confident that the system will move WNW with a turn toward the northwest by this weekend. It may stall for a day over the Bahamas with a turn toward the west toward Florida or Georgia’s coast depending on how for north the storm gets.

There are a ton of factors in play here, including how much the storm can organize in the coming days, how will it handle any land interaction with Puerto Rico or Hispaniola if it takes a track that far south and when the west turn will occur. All of this will depend on an area of high pressure that is expected to build just north the area across the mid-Atlantic this weekend into next week. This high pressure area will be key in steering the storm westward toward Florida. Several computer models have been consistent in showing this westward turn by late this weekend into early next week with a possible reemergence over the Gulf for a second landfall in the Panhandle or coastal Alabama.

The models agree on the direction in which it will move but not on its eventual strength. The Euro model really ramps the storm up and takes it into the Gulf. It actually strengthens the storm as it moves across south Florida. The GFS model doesn’t develop the system at all, which I find questionable considering the euro, Canadian and navy models all agree with It intensifying into at least a tropical storm.


1.       The potential for Florida to be affected by this system in some shape or form whether it be as a tropical depression to a high-end tropical storm.
2.       The turn toward the west at some point in its track by early next week.


1.       The eventual strength of the system. I want to see how it behaves through Friday as it moves through the Greater Antilles. How long does it stay over the Bahamas giving it time to strengthen before moving west.
2.       How fast will it move once it forms? Slower speed means longer duration effects on south Florida.

Timeframe on when this will affect the state could be as early as Sunday evening or as late as Tuesday. Hurricane hunters will head back into the storm tomorrow to take a look. I’ll send more updates as I analyze the data overnight and Wednesday.


-- Derek Beasley