*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 (sustained winds of 34 kt or greater). Note that the official NOAA definition of the ACE Index does not include those periods when the system is characterized as sub-tropical. However, we are including this information to allow for comparison between individual cyclones across all basins, many of which contain records which inadequately distinguish between tropical and subtropical cyclones. For a complete description of the ACE Index see Bell and Chelliah (2006), Journal of Climate (19) 590-612. |
The Australian Scale for Tropical Cyclones |
Note: based on estimates or observations of the strongest wind gust. |
Category | Kilometers Per Hour (km/h) | Knots (kt) | Miles Per Hour (mph) |
Cat 1 |
125 or less | 67 or less | 78 or less |
Cat 2 |
125-169 | 67-91 | 78-105 |
Cat 3 |
170-224 | 92-121 | 106-139 |
Cat 4 |
225-279 | 121-151 | 140-173 |
Cat 5 |
280 or greater | 151 or greater | 174 or greater |
Category | Miles Per Hour (mph) | Knots (kt) | Kilometers Per Hour (km hr-1) |
Tropical Storm (TS) |
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 |
156 or greater | 136 or greater | 250 or greater |
http://www.ncdc.noaa.gov/oa/climate/research/2007/2007-aussie-trop-cyclones.html
Downloaded Wednesday, 24-Sep-2008 18:34:43 EDT Last Updated Thursday, 06-Dec-2007 09:40:37 EST by David.Levinson@noaa.gov Please see the NCDC Contact Page if you have questions or comments. |