Decoding Guide

Extended Weather Depiction Chart


This product provides a quick overview of sky conditions, ceilings, precipitation and obstructions-to-visibility for selected observation stations. In addition, areas of instrument flight rules (IFR) and marginal visual flight rules (MVFR) are outlined.



Data Sources:

Hourly surface observations (human observers and automated stations)


Green shaded Areas indicate IFR conditions. Areas enclosed by a green line, but not shaded, indicate marginal VFR conditions. All other areas are VFR. The number of observations used to generate the report is printed on the left side of the chart.

In addition to the green shading, station observations are also plotted on the map in white. Each observation is depicted as follows:

Depiction Format

Sky Coverage Symbols

Sky ConditionSky Clear
Sky ConditionScattered
Sky ConditionBroken
Sky ConditionOvercast
Sky ConditionSky obscured
Sky ConditionObservation Missing

Common Precip and Obstruction Symbols

Sky Condition Continuous Drizzle
Sky Condition Continuous Rain
Sky Condition Continuous Snow
Sky Condition Light fog

Complete symbol list


Sky Condition