Plain English Meaning
A simplified weather map that shades the country into zones showing where flying conditions are good, marginal, or instrument-only, so a pilot can see at a glance what the weather looks like over a large area.
Full Definition
A surface weather chart, derived from METAR reports, that uses symbols to show areas of IFR, marginal VFR, and VFR conditions, along with cloud cover, ceiling heights, visibility, weather, and frontal positions across a wide region at a given valid time.
Context Anchor
Seen during , especially when a pilot wants a quick big-picture look at areas of , reduced visibility, or instrument conditions along a .