Surface, Prognostic, Radar and Satellite Charts

The surface analysis chart is a snapshot of current surface weather, plotting high and low pressure centers, fronts, and isobars — lines of equal pressure. Closely spaced isobars mean a strong pressure gradient and stronger wind; widely spaced isobars mean lighter wind. Prognostic charts do the opposite of a snapshot: they forecast the future position of pressure systems, fronts, and precipitation, and low-level significant weather prog charts add forecast turbulence, freezing levels, and IFR or marginal areas. Imagery fills in the rest. Weather radar shows the location and intensity of precipitation so you can avoid heavy rain and thunderstorms, remembering it depicts precipitation, not clouds. Satellite imagery shows cloud cover — visible imagery by reflected sunlight in daytime, infrared by temperature to reveal high cold tops day or night. Every one of these is a snapshot, so pair them with current reports.