Calm wind. Smoke rises vertically with little if any drift.
1
Light Air
1 to 3 mph
Direction of wind shown by smoke drift, not by wind vanes. Little if any
movement with flags. Wind barely moves tree leaves.
2
Light Breeze
4 to 7 mph
Wind felt on face. Leaves rustle and small twigs move. Ordinary wind vanes move.
3
Gentle Breeze
8 to 12 mph
Leaves and small twigs in constant motion. Wind blows up dry leaves from the
ground. Flags are extended out.
4
Moderate Breeze
13 to 18 mph
Wind moves small branches. Wind raises dust and loose paper from the ground and drives them along.
5
Fresh Breeze
19 to 24 mph
Large branches and small trees in leaf begin to sway. Crested wavelets form on inland lakes and large rivers.
6
Strong Breeze
25 to 31 mph
Large brances in continous motion. Whistling sounds heard in overhead or nearby power and telephone lines.
Umbrellas used with difficulty.
7
Near Gale
32 to 38 mph
Whole trees in motion. Inconvenience felt when walking against the wind.
8
Gale
39 to 46 mph
Wind breaks twigs and small branches. Wind generally impedes walking.
9
Strong Gale
47 to 54 mph
Structural damage occurs, such as chimney covers, roofing tiles blown off, and television antennas damaged.
Ground is littered with many small twigs and broken branches.
10
Whole Gale
55 to 63 mph
Considerable structural damage occurs, especially on roofs. Small trees may be blown over and uprooted.
11
Storm Force
64 to 75 mph
Widespread damage occurs. Larger trees blown over and uprooted.
12
Hurricane Force
over 75 mph
Severe and extensive damage. Roofs can be peeled off. Windows broken. Trees uprooted. RVs and small mobile homes overturned. Moving automobiles can be pushed
off the roadways.
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hydrologic, and climate forecasts and warnings for
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and ocean areas, for the protection of life and
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