Hurricane and Tropical Storm Watches Issued: Tropical Depression Nine Takes Aim on Florida's Gulf Coast

August 30,2016
Tropical Depression Nine, still fighting wind shear, may finally gain enough steam to become a tropical storm late Tuesday, then will make its turn toward the Gulf Coast Wednesday with heavy rain and gusty winds. The system could also produce coastal flooding and isolated tornadoes.
A hurricane watch has been issued for the Florida Gulf Coast from the Anclote River Indian Pass. A tropical storm watch has been issued for the Florida Gulf Coast west of Indian Pass to the Walton/Bay County line.
(MORE: Hurricane Central)

Current Status

Tropical Depression Nine was centered nearly 350 miles west of Key West, Florida, as of Tuesday evening.

Current Storm Information

Infrared satellite imagery exhibited a decent blow-up of convection Tuesday morning from the southeast Gulf of Mexico to near and just north of the Yucatan Channel, between the western tip of Cuba and areas near Cancún, Mexico.

Infrared Satellite Image

The convection has moved closer to the center of circulation as of Tuesday afternoon, but tropical-storm-force winds are still missing, which is why the system is still a depression.

Current Satellite, Wind Shear

Measurements from Hurricane Hunter reconnaissance aircraft and dropsondes from unmanned NASA Global Hawk aerial drones have continued to measured winds below tropical storm-force, so far.
(MORE: Five Tools to Monitor Hurricanes You May Not Have Heard Of)
It remains to be seen how much wind shear will relax in the eastern Gulf of Mexico this week, and some dry air is lurking near the system, as well. Both will have a big bearing on how strong this tropical cyclone can ultimately become before its Gulf Coast landfall.

Water Vapor Satellite Image

Forecast Track/Intensity

As the 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 reasons we mentioned above.
(MORE: Where Every U.S. Hurricane Has Hit Since 1985 | Record Gulf Hurricane Drought)
After its Gulf landfall, Hermine will track close enough to the coast of Georgia and the Carolinas Thursday night into early Saturday to bring wind and rain, there.

One Certain Impact: 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. Therefore, bands of heavy rain could train along and south of its path over the Florida peninsula possibly into Friday.
The heaviest total rainfall from this system 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 slug of heavy rain may also push northeast into southern Georgia and the eastern Carolinas Thursday night through Friday. Some localized flooding will be possible depending on the track of the low.

Coastal Flooding, Gusty Winds and Tornadoes Also Possible

The combination of heavy rainfall and storm surge around the time of the system's landfall Thursday could combine to produce dangerous flooding along parts of Florida's Gulf Coast.
Water rise from storm surge alone could reach 3 feet, or locally a bit higher, along the Florida Gulf Coast well north of St. Petersburg/Clearwater to the east side of Apalachee Bay, according to the NHC.
(MAP: NHC Storm Surge Potential Forecast)
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.
Gusty winds will accompany the storm at landfall both near the center of circulation and in squalls away from the low.
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.
In addition, as with many landfalling tropical cyclones, there's a threat of tornadoes embedded in rainbands primarily Thursday in parts of north Florida and south Georgia.
Gusty winds could also affect a swath from coastal Georgia to the coastal Carolinas Thursday night through Friday. High surf and some coastal flooding would also be possible depending on the track of the low.
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