Weather maps are maps linking measurements of air pressure, at innumerable locations, and the resulting winds and other weather conditions that result. High and low pressure areas and resulting conditions are constantly changing. The following site shows the weather map for the U.S. in real time. https://www.weather.gov/oun/sfcmaps
Follow it over the course of few days to have kids observe changes and how they correspond to weather. Please post questions that kids ask.