Weather Facts

What is an Isobar?

An isobar is a line on a weather map that connects points of equal barometric pressure. The map is sometimes called a ìCurrent Surface Analysis Mapî. The closer these lines are packed together, the windier it will be in that particular area. Many times during the colder months of the year, you will find a low pressure area over the North Atlantic surrounded by numerous isobars and you can bet that it is extremely windy near that low. Ask any mariner who sails through those storms. During the warmer months of the year, lows arenít as intense, so you wonít normally see that many isobars packed closely together. That is why the summer months are not normally that windy in most of the U.S. However, there is one exception and that is the hurricane. Isobars right around the eye of a hurricane are incredibly close together.