We are closely watching the slow development of Invest 99. Hurricane Hunters flew into it this morning, and good news...it is still not developed! Actually, it looks worse than it did 24 hours ago. It is a broad area of low pressure - meaning a large area of circulation, and it continues to lack a well-defined center. The system remains disorganized as it sits north of the Island of Hispaniola.
Most of the storms are now absent from the system. The nearest ones are over the Dominican Republic and Haiti, not near the center of lowest pressure thanks to moderate wind shear and dry air aloft. You need the storms to be close to and around the center for it to develop. If it can get better organized, there is a chance it could become a tropical depression, but it does not look like that will happen for at least a few days as it quickly moves to the WNW at 21 mph. Another thing you typically need for development is for the movement to be less than 18 mph - something it doesn't have right now. Hurricane Hunters will fly into it again later today, so we will get some more data from it into the models.
Forecast models are still not agreeing with how strong it will be or where it will go. There is a very wide spread in the models. The eastern side of the models show it could move NW and stay east of Florida without ever making landfall. The western spread show it could go across the Gulf of Mexico and make a landfall over South Texas or Mexico. This morning, the GFS shows little development of the system, and has it moving up the West Coast of Florida. The Euro (ECMWF) still develops it into a possible hurricane, but now has it over the West Coast of Florida. (See images below) Yesterday, the Euro had it over Western Louisiana. There is an upper-level area of high pressure over the Eastern U.S., and this is what will steer Invest 99. If it is weak, then it would pull the system more to the north. If it is weak, then it would steer it more to the NW and West. We will also have to watch this to see how strong it gets. There is a chance that if this system can get out of the dry air and wind shear over the Bahamas, it could develop into something this weekend. Also, if it could make it into the Gulf, there is a chance it could try to develop into something there since conditions are more favorable for development. Again, we will have to wait and see.
|0Z 8/25/16 ECMWF, forecast time 1 AM Wednesday, Aug. 31|
Clearly, there are A LOT of uncertainties with this system, and it is too early to speculate on what specific impacts might occur from the Bahamas, Florida or Gulf of Mexico. Right now, it looks like this could be at least a heavy rain maker for Hispaniola, Bahamas and Florida regardless if it develops.
Here is my Noon Weathercast Update on Invest 99:
What you should do now:
It is not the time to get overly excited about this, but just stay weather aware. It is the end of August, and historically we are in the Prime for tropical systems to come toward Louisiana. Stay tuned for updates later today. -Dave