In light of the wind allegations at this years 2011 Desert Storm Poker Run. I found an interesting chart when doing knots to mph conversions.
Windspeed in MPH Description -
Visible Condition 0
Calm smoke rises vertically 1 - 4
Light air direction of wind shown by smoke but not by wind vanes 4 - 7
Light breeze wind felt on face; leaves rustle; ordinary wind vane moved by wind 8 - 12
Gentle breeze leaves and small twigs in constant motion; wind extends light flag 13 - 18
Moderate breeze raises dust and loose paper; small branches are moved 19 - 24
Fresh breeze small trees in leaf begin to sway; crested wavelets form on inland water 25 - 31
Strong breeze large branches in motion; telephone wires whistle; umbrellas used with difficulty 32 - 38
Moderate gale whole trees in motion; inconvenience in walking against wind 39 - 46
Fresh gale breaks twigs off trees; generally impedes progress 47 - 54
Strong gale slight structural damage occurs; chimney pots and slates removed 55 - 63
Whole gale trees uprooted; considerable structural damage occurs 64 - 72
Storm very rarely experienced; accompanied by widespread damage 73+
Hurricane devastation occurs.
Good reference chart really makes you think that most wind speeds are greatly exaggerated...I'm guilty of it as well.