Isobars that are close together indicate strong winds due to a large pressure difference over a small area, while isobars farther apart show gentler winds from a smaller pressure change. Isobars also show locations of high and low pressure areas. Air pressure decreases with increasing altitude as there are fewer air molecules, and high and low pressure systems affect incoming weather, with high pressure typically bringing cooler and clearer conditions and low pressure often accompanying warmer temperatures, storms and rain.
