Synoptic Weather Chart

A weather map showing analysed or forecast atmospheric conditions over a broad area at a stated time.

It commonly depicts mean-sea-level pressure with isobars, high- and low-pressure centres, fronts and troughs and may include observations or other meteorological features. Analysis charts represent a best estimate of conditions at the valid time, while forecast charts show model-informed expected development.

Isobar spacing and system movement help infer wind and weather, but local coast, terrain, stability and convection can differ from the broad pattern. The valid time, chart type, units, source and later updates must be checked before use.