Details of The Method
| T-Number | 1-min Winds | Category | Min. Pressure | |||
|---|---|---|---|---|---|---|
| Atlantic | NW Pacific | |||||
| 1.0 - 1.5 | 25 | 29 | 46 | TD | ---- | ---- |
| 2.0 | 30 | 35 | 56 | TD | 1009 | 1000 |
| 2.5 | 35 | 40 | 65 | TS | 1005 | 997 |
| 3.0 | 45 | 52 | 83 | TS | 1000 | 991 |
| 3.5 | 55 | 63 | 102 | TS | 994 | 984 |
| 4.0 | 65 | 75 | 120 | Cat 1 | 987 | 976 |
| 4.5 | 77 | 89 | 143 | Cat 1–2 | 979 | 966 |
| 5.0 | 90 | 104 | 167 | Cat 2–3 | 970 | 954 |
| 5.5 | 102 | 117 | 189 | Cat 3 | 960 | 941 |
| 6.0 | 115 | 132 | 213 | Cat 4 | 948 | 927 |
| 6.5 | 127 | 146 | 235 | Cat 4 | 935 | 914 |
| 7.0 | 140 | 161 | 260 | Cat 5 | 921 | 898 |
| 7.5 | 155 | 178 | 287 | Cat 5 | 906 | 879 |
| 8.0 | 170 | 196 | 315 | Cat 5 | 890 | 858 |
In a developing cyclone, the technique takes advantage of the fact that cyclones of similar intensity tend to have certain characteristic features, and as they strengthen, they tend to change in appearance in a predictable manner. The structure and organization of the tropical cyclone are tracked over 24 hours to determine if the storm has weakened, maintained its intensity, or strengthened. Various central cloud and banding features are compared with templates that show typical storm patterns and their associated intensity. If infrared satellite imagery is available for a cyclone with a visible eye pattern, then the technique utilizes the difference between the temperature of the warm eye and the surrounding cold cloud tops to determine intensity (colder cloud tops generally indicate a more intense storm). In each case a "T-number" and a Current Intensity (CI) value are assigned to the storm. These measurements range between 1 (minimum intensity) and 8 (maximum intensity). The T-number and CI value are the same except for weakening storms, in which case the CI is higher. For weakening systems, the CI is held as the tropical cyclone intensity for 12 hours, though research from the National Hurricane Center indicates that six hours is more reasonable. The table at right shows the approximate surface wind speed and sea level pressure that corresponds to a given T-number. The amount a tropical cyclone can change in strength per 24 hour period is limited to 2.5 T-numbers per day.
Read more about this topic: Dvorak Technique
Famous quotes containing the words details of, details and/or method:
“Anyone can see that to write Uncle Tom’s Cabin on the knee in the kitchen, with constant calls to cooking and other details of housework to punctuate the paragraphs, was a more difficult achievement than to write it at leisure in a quiet room.”
—Anna Garlin Spencer (1851–1931)
“If my sons are to become the kind of men our daughters would be pleased to live among, attention to domestic details is critical. The hostilities that arise over housework...are crushing the daughters of my generation....Change takes time, but men’s continued obliviousness to home responsibilities is causing women everywhere to expire of trivialities.”
—Mary Kay Blakely (20th century)
“Letters are above all useful as a means of expressing the ideal self; and no other method of communication is quite so good for this purpose.... In letters we can reform without practice, beg without humiliation, snip and shape embarrassing experiences to the measure of our own desires....”
—Elizabeth Hardwick (b. 1916)