Enhanced F Scale for Tornado Damage
This update to the the original F-scale has been made by meteorologists and wind engineers. It is to be implemented in the on 1 February 2007.
Original F Scale Enhanced F scale Idicators
FUJITA
SCALE |
DERIVED
EF SCALE |
OPERATIONAL
EF SCALE |
||||
F
Number |
Fastest
1/4-mile (mph) |
3
Second Gust (mph) |
EF
Number |
3
Second Gust (mph) |
EF
Number |
3
Second Gust (mph) |
0 |
40-72 |
45-78 |
0 |
65-85 |
0 |
65-85 |
1 |
73-112 |
79-117 |
1 |
86-109 |
1 |
86-110 |
| 2 |
113-157 |
118-161 |
2 |
110-137 |
2 |
111-135 |
3 |
158-207 |
162-209 |
3 |
138-167 |
3 |
136-165 |
4 |
208-260 |
210-261 |
4 |
168-199 |
4 |
166-200 |
5 |
261-318 |
262-317 |
5 |
200-234 |
5 |
Over
200 |
IMPORTANT NOTE ABOUT ENHANCED F-SCALE WINDS, The Enhanced F-scale still is a set of wind estimates (not measurements) based on damage. Its uses three-second gusts estimated at the point of damage based on a judgment of 8 levels of damage to the 28 indicators listed below. These estimates vary with height and exposure. Important: The 3 second gust is not the same wind as in standard surface observations. Standard measurements are taken by weather stations in open exposures, using a directly measured, "one minute mile" speed.