12:45 PM | *The tropics are alive and well and U.S. impact is quite likely*

Colorized IR image of the Atlantic Basin with multiple systems of interest; courtesy Penn State eWall

Overview
The climatological peak of the Atlantic Basin hurricane season is around the middle of September and tropical activity has certainly ramped up right on schedule.  There are four different systems in the western part of the Atlantic Basin that bear watching over the next few days, an additional wave in the eastern Atlantic, and an impressive wave over the western part of Africa.  The tropical system known last week as "99L" is now classified as a tropical depression (#9) and it could very well end Florida’s hurricane drought later this week.  Another tropical depression (#8) is spinning towards the Outer Banks of North Carolina and it could reach tropical storm status over the next few days.  The strongest system right now is Hurricane Gaston and it is located out over the open Atlantic and should not have any direct impact on the US.  Meanwhile, a fourth system that is currently unnamed and unnumbered is noticeably spinning east of the Bahamas - and it too bears watching.  The wave over the west coast of Africa will be something to watch closely over the next 10 to 14 days or so.

Climatological peak in the Atlantic Basin hurricane season is right around September 10th; courtesy NOAA/NHC

Tropical Depression #9
Amazingly, the state of Florida has not had a hurricane of any intensity since Wilma came ashore in southwestern Florida during late October of 2005. Hurricane Wilma was also the last major hurricane (i.e., category 3, 4 or 5) to strike US soil in what has turned out to be another amazing streak.  Both of these streaks are unprecedented in the record-keeping era and there certainly is a chance the Florida hurricane drought comes to an end later this week.  Tropical depression #9 is pounding western Cuba today with heavy rainfall and this system will spill out over the Gulf of Mexico in the next 12-24 hours or so.  Once over the warm waters of the Gulf of Mexico, intensification is likely to take place.  Much of the Gulf of Mexico is currently seeing sea surface temperatures at or above 85°F and this is above-normal in most sections for this (warm) time of year.  Indications are that the tropical system will begin to curve around to the northeast during the mid-week time period and then potentially reach the Gulf coastal side of Florida from the west around Thursday as a tropical storm or hurricane.  All eyes from Tampa to Tallahassee should monitor this system closely over the next few days.  After that, it'll likely continue to head to the northeast and affect eastern sections of Georgia, South Carolina and the Carolinas early this coming holiday weekend.  

Tropical Depression #8
Meanwhile, while all eyes were focused on "99L" last week, another system kind of stuck up on the eastern Carolinas.  This system is spinning towards the Outer Banks of NC and may reach tropical storm status before arriving in the mid-week time period.  At the point, odds favor a quick turn to the northeast during the mid and late week time period - and away from the Mid-Atlantic coastline.

IR satellite image of African and the eastern Atlantic with a couple of tropical waves of interest; courtesy University of Wisconsin/CIMSS

African wave
Elsewhere, an impressive wave is just now pushing off the western coast of Africa.  This system looks like it’ll take a "southern track" which is always worrisome for the Caribbean Sea region and/or the coastal region of the US as this kind of path generally lessens the chances of an open Atlantic or “out-to-sea” type of result.  This unfolding tropical wave is likely to become a real concern in about ten days or so which happens to be pretty close to - you guessed it - the climatological peak of September 10th.  
  
Stay tuned.

Wind map showing circulation center just off the African coastline; courtesy earth.nullschool.net

Meteorologist Paul Dorian
Vencore, Inc.