Winds aloft barbs point to the direction that the winds are blowing from. The barbed end points towards the “from” direction and the dotted end points towards the “to” direction.
Short barbs indicate 5 knots of wind. Tall barbs indicated 10 knots. Triangular (or pennants) barbs indicate 50 knots. Simply add the sum of the values represented by the barb symbols to determine the wind speed.