The former tells you, yes the wind is blowing from this direction and the later that the wind was blowing in that direction The former you use to make real time decisions about what your next action is going to be and the latter for accident investigation and coroners inquests!! Foam or Whitecaps provide wind speed and direction Foam or whitecaps provide an indication of direction (the foam appears to move upwind into the wind) and speed (it generally takes winds of 1015 knots or more to produce whitecaps and foam)The way a weather vane is pointed by prevailing winds indicates the direction from which the wind is blowing The larger opening of a windsock faces the direction that the wind is blowing from;
Finding Warm Fronts Using Wind Direction Shift From East Southeast To South Southwest
