A weather map showing jet streams, troughs, and ridges over the northern Atlantic and parts of Europe and North America with forecast information and wind speed values.

Mid-Level SigWx Chart

The Aviation Weather Center (AWC) issues a Mid-Level Significant Weather Prognostic chart for the North Atlantic Ocean Region that covers a range of flight levels from 10,000 ft MSL to FL450. The chart is issued four times daily and depicts significant en route weather phenomena that can be hazardous to aviation, such as icing and turbulence.