WeatherXplore CWA

Center Weather Advisory

What are CWAs? These advisories give warnings to ATC and pilots about hazardous weather over very large areas.  CWAs are valid for up to 2 hours and may include forecasts of conditions expected to begin within 2 hours.

A CWA is issued when any of the following conditions occur:

• Conditions meeting Convective SIGMET criteria
• Icing – moderate or greater
• Turbulence – moderate or greater
• Heavy and extreme precipitation
• Freezing precipitation
• Conditions at or approaching low IFR (LIFR)
• Surface wind gust at or above 30kts
• LLWS (low-level wind shear, surface to 2,000’agl)
• Volcanic ash, duststorms, or sandstorms
• When a hazard has grown significantly outside of the boundary defined by the AWC (aviation weather center) or AAWU (Alaska aviation weather unit) advisory
• To upgrade a thunderstorm advisory to include severe thunderstorms
• To upgrade an AIRMET to include isolated severe turbulence or icing
• To define a line of thunderstorms within a larger area covered by the AWC or AAWU advisory
• Anything that in the judgment of the CWSU forecaster will add value to an existing advisory

The Scenario

You are flying along getting flight following from approach.  You hear the audio clip below on frequency (click below to listen).  This prompts you to request a frequency change momentarily to contact flight service and receive an updated weather briefing in flight to ensure the severe weather described is not moving towards your route of flight.