How to read a barometer?

How do I read a Barometer%0D%0A?

• Answer:

  A barometer shows you the atmospheric pressure. But, unless you live near the sea level, you should first correct it for your altitude. The easiest way to do this is by finding the current pressure at that moment. You can e.g. fing the METAR for your local airport and read the QNH, which will be the number directly following the letter Q. A barograph, that records the pressure over time, is even better. In the old days, barographs were complexes, with a clockwork and a pen that needed ink. Today, cheap electronic do the same work much better. Knowing the pressure is interesting but knowing how it falls or rises over time, will give you the wind force with great certainty. Seafarers say that e.g. a fall or a rise of 10 millibars in a period of 8 hours is a sure sign that a gale force wind is on its way.