Tropical Depression Ten was a tropical depression that did not reach tropical storm strength during the 2007 Atlantic hurricane season. The depression developed on September 21 in the eastern Gulf of Mexico while located a short distance south of the Florida Panhandle. The depression initially started out as a subtropical cyclone due to its involvement with an upper-level low, but as the upper low moved away, it became a tropical cyclone prior to its landfall near Fort Walton Beach. The depression dissipated on 22, just a day after forming.
The depression caused $6.2 million (2007 USD) in damage, but no deaths.
|Formation||September 21, 2007|
|Dissipation||September 22, 2007|
|Highest winds||35 mph|
|Lowest pressure||1005 mbar|
|Damages||$6.2 million (2007 USD)|
|Areas affected||Leeward Islands|
|Part of the||2007 Atlantic hurricane season|
Tropical Depression Ten had a complex origin, forming from interaction between an upper-level low, the tail end of a decaying frontal boundary, and a tropical wave. This wave moved off the coast of Africa on September 6, and was also the same one that spawned Tropical Storm Ingrid in the central Atlantic Ocean. On September 17, a portion of this wave reached the Bahamas, where it produced a disorganized area of showers and thunderstorms. During this time, a cold front moved southward across the eastern United States and became stationary across central Florida and the adjacent western Atlantic Ocean. The front produced a large area of convection that extended from northern Florida northeastward into the western Atlantic for several hundred miles. Initially, the areas of convection associated with the front and the tropical wave were indistinguishable, but on September 18, the two areas merged as a large upper-level low developed over Florida, which produced a broad surface low across the northwestern Bahamas. As the upper low moved westward across central Florida over the next 24 hours, it intensified. Since the surface low was still involved with the upper-level low, convection remained disorganized and multiple circulation centers were embedded within the low as moved into the eastern Gulf of Mexico. Around 1200 UTC September 21, one of the aforementioned multiple circulation centers became the dominant one, and it is estimated that the system developed into Subtropical Depression Ten during this time while it was located about 40 miles southwest of Apalachicola, Florida. It was designated a subtropical cyclone rather than a tropical cyclone, because it was still involved with the aforementioned upper-level low.
During the afternoon of September 21, as the depression separated from the upper low, it quickly acquired tropical characteristics, and became a tropical depression as convection increased near the circulation. The depression moved west-northwest with no significant development until landfall occured along the Florida Panhandle near Fort Walton Beach at around 0000 UTC September 22. Shortly after its landfall, the cyclone degenerated into a remnant low. The remnant low continued moving northward and dissipated over southwestern Alabama shortly after 0600 UTC that day.
As the first advisory on the system was issued, a Tropical Storm Warning was issued from Apalachicola, Florida westward to the mouth of the Mississippi River. Shortly thereafter, an inland Tropical Storm Warning was issued for for Pearl River, Walthall, and Pike counties in Mississippi as well as Washington Parish in Louisiana. The National Weather Service in New Orleans issued a Coastal Flood Watch for four coastal parishes in southeast Louisiana. In Mississippi, Governor Haley Barbour declared a state of emergency. Officials ordered evacuations for residents in low-lying areas and in mobile homes in Jackson, Harrison, and Hancock counties. Officials in New Orleans opened up three storm shelters, citing the potential need of shelters for residents living in about 17,000 FEMA trailers following Hurricane Katrina. Louisiana Governor Kathleen Blanco declared a state of emergency and placed the National Guard and other disaster services on standby.
Prior to the formation of the cyclone, several oil and gas companies evacuated unneeded employees from oil platforms across the northern Gulf of Mexico, with Shell evacuating around 700 people, while Noble Energy evacuated around 300 people from two oil rigs. Exxon Mobil cut its output by 1,000 barrels of oil and 55,000 feet. With 27.7% of the daily crude oil production halted due to the depression, oil prices rose further after days of increasing levels, and on September 20 reached a record rate of over $84 per barrel.
About 12 hours prior to the formation of the cyclone, outer rainbands began moving onshore the Florida Panhandle. Also, an EF1 tornado was spawned near the town of Eustis, thanks to a supercell that developed near Lake Apopka. The tornado tracked about 2 miles, and reached estimated wind speeds of 100 mph. The tornado destroyed 20 homes, severely damaged 30 others, injured one person, and caused around 300 residents to lose electricity. Total damage from this tornado reached $6.2 million (2007 USD). In addition to this tornado, there were tornadoes reported in the towns of Marianna and Chipley, respectively. Also, the precursor disturbance to the cyclone produced lightning that struck and killed a man in Hendry County.
Wave heights in excess of 5 to 10 feet were reported along Florida's west coast, although no beach erosion was reported. The highest rainfall with the storm was 7.29 inches, occuring in the town of Hastings. Elsewhere, rainfall totals reached 1.46 inches in Albany, Georgia, as well as 0.51 inches in Dothan, Alabama. In Milton, Florida, the cyclone produced a wind gust of 46 mph, which blew a few trees down in Escambia County. The depression produced a minor storm surge of 2.5 feet along the Florida Panhandle.
Tornado damage in Eustis, Florida from the aforementioned EF1 tornado.
Rainfall totals from Tropical Depression Ten.