In the computer models section, there are forecast wind charts available at a whole variety of resolutions and height levels. These charts are showing the predicted strength and direction of the wind at that level of the atmosphere.
The wind is blowing from the direction where the barbs on the wind stick are pointing, to the empty end of the wind stick. Each full barb represents 10 knots and each half barb 5 knots. A triangle completely shaded in represents 50 knots.