Which atmospheric phenomenon is indicated by closely spaced isobars on a weather map?

Closely spaced isobars on a weather map are indicative of strong wind speeds. Isobars are lines that connect points of equal atmospheric pressure, and when they are close together, it indicates a steep pressure gradient. This steep gradient means that the difference in atmospheric pressure over a short distance is significant, resulting in increased wind speeds as air moves from high-pressure areas to low-pressure areas.

In contrast, widely spaced isobars suggest calmer weather conditions and weaker winds, as the pressure changes over a larger area are more gradual. Therefore, the presence of closely spaced isobars is a strong signal to meteorologists that significant winds are likely to occur. This relationship between isobars and wind speed is a fundamental principle in meteorology and helps in forecasting weather and understanding atmospheric dynamics.