Aviation Weather-Center Weather Advisory: What are CWAs?

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, dust storms, 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
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 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, dust storms, 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 @Fly8MA