Tropical Depression Nine Struggles in Gulf of Mexico; Will Soak the Northeast Gulf Coast This Week

August 29,2016
Tropical Depression Nine may struggle a bit in the southern Gulf of Mexico before finally making a Gulf Coast landfall later this week with soaking rain and gusty winds.
This latest system was designated a tropical depression Sunday after a Hurricane Hunter reconnaissance mission finally found a sufficiently organized low-pressure center with collocated shower and thunderstorm activity.
(MORE: Hurricane Central)

Current Status

Tropical Depression Nine was centered about 170 miles west-southwest of Key West, Florida, as of late Monday morning.

Current Storm Information

Infrared satellite imagery shows a fair amount of convection over western Cuba and points south.

Infrared Satellite Image

However, this convection isn't really near the center of Tropical Depression Nine, as indicated by a Hurricane Hunter reconnaissance mission Monday morning.
This is due to northerly wind shear, blowing the convection away from the center of circulation.

Current Satellite, Wind Shear

For a tropical cyclone to intensify, wind shear needs to relax in order to allow convection to cluster near the center of circulation.
It remains to be seen how much wind shear will relax in the eastern Gulf of Mexico this week, which will have a big bearing on how strong this tropical cyclone can ultimately become.

Forecast Track/Intensity

As the National Hurricane Center's (NHC) forecast path shows, this tropical cyclone is forecast to eventually turn northeast on a path toward the Florida Gulf Coast Thursday.

Projected Path

At this time, the NHC expects this system to be a tropical storm as it approaches the Florida Gulf coast later this week. However, the intensity forecast for this system is more uncertain than usual, for the reason we mentioned above.
(MORE: Where Every U.S. Hurricane Has Hit Since 1985 | Record Gulf Hurricane Drought)
After its Gulf landfall, some uncertainty remains on whether this tropical cyclone will track close enough to the coast of Georgia and the Carolinas Friday into early Saturday to bring some wind and rain, there.

One Certain Impact: Florida, Cuba Heavy Rain

The threat of heavy rainfall is not a function of tropical cyclone intensity, but rather the system's slow movement and availability of deep, tropical moisture, as we saw with an unnamed system earlier this month triggering Louisiana's epic flooding.

Radar, Watches, and Warnings

Fortunately, this system will accelerate to the northeast from Wednesday on. That faster forward motion will mitigate the heavy rain threat somewhat.
However, this system will have a deep fetch of tropical moisture along its eastern and southern flank.
So, for now, the heaviest total rainfall from this tropical system through Friday appears to line up over western Cuba, South and central Florida, including the Florida Keys, where many locations look primed to pick up at least 3 inches of total rainfall.
(FORECAST: Miami | Key West | Tampa)

Rainfall Outlook Through Friday

Of course, where bands of heavy rain stall, over 3 inches of rain could fall in an hour or so, leading to serious flash flooding, particularly in urban areas.
(MORE: Rainfall Flood Concern for Saturated Gulf Coast)
A rather expansive swath of the Gulf Coast region has been soaked in August, including the Florida panhandle

August 2016 rainfall, through August 23.

Assuming this system does strengthen, high surf would begin to build along the Gulf Coast of Florida by Wednesday, peaking Thursday, with some coastal flooding likely, as well.
The magnitude of wind and/or storm surge impacts from this system will ultimately depend on the exact intensity and track of the system later this week.
For now, if you have interests anywhere in Florida and along the Southeast coast, check back with us at weather.com for any important forecast changes in the days ahead.
(MORE: Most Intense U.S. Landfalls Have Happened in a 17-Day Period)
Now is a good time to make sure you have a plan before a hurricane hits.

Storm History

Before this system formed into a tropical cyclone, it soaked parts of the Caribbean, Bahamas and Cuba.
Late last week, more than 1,700 people were displaced from their homes in the Dominican Republic due to heavy rainfall.

MORE: Retired Atlantic Hurricane Names