The weather depiction chart, which is issued every three hours, shows weather conditions at certain weather stations, and also displays the weather conditions in terms of visual, marginal, and instrument.
It provides a bigger picture, and is useful for initial flight planning.
The chart is computer prepared from surface observations and gives a broad overview of the observed flying category conditions at the valid time for the chart.
Station Plot Model
On the chart, a station model shows the sky condition as the portion of the station symbol which is filled.
The station model is labeled with the visibility when the station reports a visibility of five miles or less.
The present weather is shown by a symbol to the left of the station model.
If a ceiling exists, it is shown below the station model in hundreds of feet.
Automated or Manual Station
If a right bracket symbol is placed to the right of the station model, it indicates an automated weather reporting station.
MVFR and IFR Weather Conditions
The weather depiction chart shows areas of marginal and instrument weather conditions as outlines by a solid line.
Marginal weather areas are outlined and not shaded, and instrument weather areas are outlined and shaded.