Isobar
/ˈaɪsəbɑːr/
Definition 1 of 2
Pro Tip 1/3Weather Prediction
Isobars help forecast weather, indicating if it’s likely to be windy or calm. 
Meteorologists can predict storms by analyzing the isobar patterns on the map.
Pro Tip 2/3Close Isobars
Isobars that are close together on a map show areas of high wind speeds. 
The isobars on the weather map are so close, it's going to be a windy day.
Pro Tip 3/3Pressure Systems
Isobars form patterns that identify high and low pressure systems on maps. 
A low pressure system is surrounded by concentric isobars on the atmospheric map.