Hurricane Danielle was the fourth named storm and the third hurricane of the 2004 Atlantic hurricane season. Danielle formed on August 13 in the Atlantic Ocean southeast of the Cape Verde Islands. Danielle moved west-northwest initially, but over time it took a path out to sea, where it dissipated on August 21.
Danielle caused no damage and no deaths.
|Formation||August 13, 2004|
|Dissipation||August 21, 2004|
|Highest winds||110 mph|
|Lowest pressure||964 mbar|
|Part of the||2004 Atlantic hurricane season|
A vigorous tropical wave moved off the coast of Africa early on August 12. Before even moving off Africa, the wave possessed several characteristics associated with tropical cyclones, including a well-defined low-level circulation, banding features, as well as well-established upper-level outflow. When the wave reached the warm waters of the Atlantic Ocean about 450 miles southeast of the Cape Verde Islands, more deep convection developed over the circulation center of the wave. Rainbands also become better defined, and Dvorak classifications were taken on the wave at 1800 UTC that same day. The wave moved west-northwest at 12 to 14 knots, becoming better organized as it did so. At 1200 UTC August 13, it is estimated that the wave developed into Tropical Depression Four while located about 210 miles southeast of the southernmost Cape Verde Islands. After forming, the depression continued to become better organized because of the very favorable environmental and oceanic conditions, and it is estimated that the depression strengthened into Tropical Storm Danielle at 0000 UTC August 14. Upon reaching an intensity of 50 mph just 12 hours later, favorable environmental and oceanic conditions allowed Danielle to undergo a period of rapid intensification, and Danielle became a hurricane at 0000 UTC August 15 while located about 295 miles west-southwest of the southernmost Cape Verde Islands. Danielle continued to rapidly intensify until it reached winds of 90 mph around 1200 UTC that day. Thereafter, the cyclone began to intensify at a slower than climatological rate, possibly due the eye as well as the radius of maximum winds having decreased and subsequently stabilized to a smaller diameter. At this point, Danielle was moving northwest towards a weakness in the subtropical ridge, and at 1800 UTC August 16, Danielle reached its peak intensity of 110 mph about 755 miles west of the northwesternmost Cape Verde Islands. Shortly after peaking in intensity, a large mid- to upper-level trough that had eroded the subtropical ridge and enhanced the poleward outflow over Danielle began to induce southwesterly wind shear over Danielle.
The strong shear caused Danielle to steadily weaken over the ensuing 72 hours as Danielle moved northward into a large break in the subtropical ridge. Danielle weakened to a tropical storm at 1200 UTC August 18 and then turned northeast under the influence of moderate mid-level southwesterly flow ahead of the approaching trough. The shear continued to increase and most of the convection to become removed from the circulation center, and Danielle weakened to a tropical depression at around 1800 UTC August 20 while located about 600 miles south-southwest of the westernmost Azores Islands. Danielle continued to weaken while moving west-northwest around the southern periphery of a ridge of high pressure situated over the Azores. At 1800 UTC August 21, Danielle degenerated into a remnant low. Danielle's remnants moved slowly northwestward, remaining devoid of significant deep convection for the next three days. Danielle's remnants finally dissipated at 0000 UTC August 25 while located about 690 miles west-southwest of the westernmost portion of the Azores Islands.
Lack of Retirement
Because it did not affect land, the name Danielle was not retired in the Spring of 2005 by the World Meteorological Organization. It is on the list of names to be used for the 2010 Atlantic hurricane season.