Ocean Basin Tropical Cyclone Cyclogenesis Date Cyclolysis Date Saffir-Simpson Category Maximum 6-hr Sustained Wind (kt) Maximum 6-hr Wind Gust (kt) Accumulated Cyclone Energy (ACE*) Index (kt2)
Atlantic
 Alex 7/31/04 8/5/04 Cat 3 105 130 11.1675 x 104
Atlantic
 Bonnie 8/9/04 8/12/04 TS 55 65 2.4975 x 104
Atlantic
 Charley 8/9/04 8/15/04 Cat 4 125 150 10.4375 x 104
Atlantic
 Danielle 8/13/04 8/21/04 Cat 2 90 110 11.950 x 104
Atlantic
 Earl 8/13/04 8/16/04 TS 40 50 1.045 x 104
Atlantic
 Frances 8/25/04 9/7/04 Cat 4 125 155 46.7975 x 104
Atlantic
 Gaston 8/27/04 9/1/04 Cat 1 65 75 2.175 x 104
Atlantic
 Hermine 8/29/04 8/31/04 TS 45 55 1.0125 x 104
Atlantic
 Ivan 9/3/04
9/22/04		 9/17/04
9/24/04		 Cat 5 145 175 69.950 x 104
Atlantic
 Jeanne 9/14/04 9/27/04 Cat 3 100 120 24.8921 x 104
Atlantic
 Karl 9/17/04 9/24/04 Cat 4 120 145 27.990 x 104
Atlantic
 Lisa 9/20/04 10/3/04 Cat 1 65 80 11.9925 x 104
Atlantic
 Matthew 10/8/04 10/10/04 TS 40 50 0.7725 x 104
Atlantic
 Nicole 10/10/04 10/11/04 Sub-TS 45 55 1.1625 x 104
Atlantic
 Otto 11/30/04 12/??/04 TS 45 55 1.050 x 104

2004 Total Atlantic Ocean ACE Index = 224.892 x 104 kt2

*The Accumulated Cyclone Energy (ACE) Index is calculated by summing the squares of the estimated 6-hourly maximum sustained wind speed in knots (Vmax2) for all periods in which the tropical cyclone is a tropical storm or greater intensity. For a complete description of the ACE Index see Bell et al. (2000), Bulletin of the American Meteorological Society (81) S1-S50.


The Saffir-Simpson Scale for Tropical Cyclones

Category Miles Per Hour (mph) Knots (kt) Kilometers Per Hour (km hr-1)
Tropical Storm
 39-73 34-63 63-118
Cat 1
 74-95 64-82 119-153
Cat 2
 96-110 83-95 154-177
Cat 3
 111-130 96-113 178-209
Cat 4
 131-155 114-135 210-249
Cat 5
 155 135 249


http://www.ncdc.noaa.gov/oa/climate/research/2004/ann/atlantic-2004-ace.html
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Last Updated Tuesday, 29-Nov-2005 14:04:09 EST by David.Levinson@noaa.gov
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