Isotach

Isotach maps are a measurement of wind speed, usually measured every hour or more. These lines are called wind bars which indicate wind speed ans wind direction. Note their likeness to a weather vane. The back of the vain is where you will see the smaller bars indicating wind speed. The short bar indicates 5mph/knots, the longer ten mph/knots and a flag indicates 50 plus mph/knots. These barbs help in understanding weather pattern and predicting weather. The wind speed and direction as well as barometric pressure all work together in predicting weather.


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