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Tropical Depression Seven was a minor and short lived tropical depression. The seventh cyclone of the 2002 Atlantic hurricane season, it remained out over open waters for the duration of its existence. The depression formed out of a tropical wave which developed off the eastern coast of Africa on September 1. The wave traveled across the Atlantic basin over the next week before being declared Tropical Depression Seven on September 7. Shortly after being declared a depression, strong wind shear impacted the storm, causing it to weaken. The depression dissipated the next day while located 980 mi (1580 km) southeast of Bermuda.
The origins of Tropical Depression Seven can be traced back to a well organized tropical wave which emerged from the eastern coast of Africa on September 1. The wave produced strong convection and had developed a low level circulation. However, the wave rapidly became disorganized and the convection around the center dissipated. The wave, moving towards the west-northwest, continued to track across the Atlantic basin for the next week before becoming better organized. On September 7, the tropical wave was determined to have developed sufficient organization to be declared Tropical Depression Seven while located 1155 mi (1855 km) east-southeast of Bermuda. The depression was upgraded due to convection persisting around the center of the small circulation, and intensity estimates using the Dvorak technique—a system used to estimate the intensity of a tropical cyclone—rendered T2.0, which corresponds to an intensity of 35 mph (55 km/h). Using that estimate, the pressure was estimated at 1009 mbar (hPa; 29.79 inHg). However, the pressure was reassessed in the post-season analysis to have only been 1013 mbar (hPa; 29.93 inHg). The depression was being influence by a ridge located to the north of the storm, causing it to move towards the northwest at 8 mph (13 km/h). The depression was not forecast to strengthen further as it was in an area of strong wind shear.
Shortly after being declared a tropical depression, wind shear began to take its toll on the storm. The western side of the storm began to erode and the center of the storm became partially exposed. In the late night hours of September 7, the strong wind shear already tearing apart the western side of the depression was forecast to move towards the center and increase in intensity, leaving no chance for the depression to develop. The ridge of high pressure located to the north of the depression began to weaken, causing the foreword motion of the storm to decrease slightly. By the morning of September 8, the center of Tropical Depression Seven was completely exposed and all of the deep convection around the storm had been torn away by the wind shear. The final advisory from the National Hurricane Center was issued later that morning as the depression was just a swirl of clouds and remained devoid of almost any convection. The lack of convection meant that the depression had degenerated into a remnant low-pressure area. The storm dissipated shortly after as strong wind shear continued to cause the storm to deteriorate while located 980 mi (1580 mi) southeast of Bermuda.
Preparations and impact
Since the small circulation of Tropical Depression Seven remained hundreds of miles from land, there were no watches or warnings issued for any land masses. There were also no ship reports of sustained winds in the depression as no ships were in the vicinity of the storm.
- ↑ 1.0 1.1 1.2 1.3 Miles B. Lawrence (2002-10-30). "Tropical Depression Seven Tropical Cyclone Report". National Hurricane Center. http://www.nhc.noaa.gov/2002seven.shtml. Retrieved 2008-10-25.
- ↑ Avila (2002-09-07). "Tropical Depression Seven Public Advisory One". National Hurricane Center. http://www.nhc.noaa.gov/archive/2002/pub/al072002.public.001.html. Retrieved 2008-10-25.
- ↑ 3.0 3.1 Avila/Nelson (2002-09-07). "Tropical Depression Seven Discussion One". National Hurricane Center. http://www.nhc.noaa.gov/archive/2002/dis/al072002.discus.001.html. Retrieved 2008-10-25.
- ↑ Lawrence (2002-09-07). "Tropical Depression Seven Discussion Two". National Hurricane Center. http://www.nhc.noaa.gov/archive/2002/dis/al072002.discus.002.html. Retrieved 2008-10-25.
- ↑ Jarvinen (2002-09-07). "Tropical Depression Seven Discussion Three". National Hurricane Center. http://www.nhc.noaa.gov/archive/2002/dis/al072002.discus.003.html. Retrieved 2008-10-25.
- ↑ Pasch (2002-09-08). "Tropical Depression Seven Discussion Four". National Hurricane Center. http://www.nhc.noaa.gov/archive/2002/dis/al072002.discus.004.html. Retrieved 2008-10-25.
- ↑ Lawrence (2002-09-08). "Remnant Low Seven Discussion Five". National Hurricane Center. http://www.nhc.noaa.gov/archive/2002/dis/al072002.discus.005.html. Retrieved 2008-10-25.