National Weather Service United States Department of Commerce
 Beaufort Wind Scale
#  MPH  Knots Description Specifications
0 < 1 < 1 Calm Smoke rises vertically.
1 1-3 1-3 Light Air Direction of wind shown by smoke drift but not by wind vanes.
2 4-7 4-6 Light Breeze Wind felt on face;
Leaves rustle; Wind vanes moved by wind
3 8-12 7-10 Gentle Breeze Leaves and small twigs in constant motion; Wind extends light flag.
4 13-18 11-16 Moderate Raises dust, loose paper; Small branches moved.
5 19-24 17-21 Fresh Small trees begin to sway; Crested wavelets form on inland waters.
6 25-31 22-27 Strong Large branches in motion; Whistling heard in telephone wires; Umbrellas
used with difficulty.
7 32-38 28-33 Near Gale Whole trees in motion; Inconvenience felt walking against the wind.
8 39-46 34-40 Gale Twigs break off trees; Wind generally impedes progress; Mobile homes
may shake.
9 47-54 41-47 Strong Gale Slight structural damage occurs; Mobile homes, sheds, roofs, lanais,
and RV's suffer minor damage.
10 55-63 48-55 Storm Small trees uprooted; Moderate damage occurs to mobile homes and RV's;
Brick and wood frame houses receive minor structural and roof damage;
Some signs blown down.
11 64-73 56-63 Violent Storm Moderate sized trees uprooted; Large branches snapped off trees;
Chimneys and road signs toppled; Significant mobile home damage;
Power lines downed.
12 74-95 64-83 Hurricane Category 1 Mobile homes overturned; Large trees and branches downed; Moderate
roof damage to wood and brick homes; Minor pier damage.