What is an unscheduled planning forecast describing conditions expected to begin sometime within the next 12 hours which may impact the flow of air traffic in a specific center's (ARTCC) area?

• A. MIS
• B. AIRMET
• C. CWA
• D. SIGMENT

Answer: (A)

The main idea is a planning forecast used by air traffic facilities to anticipate weather that could disrupt center operations. The Meteorological Impact Statement is the unscheduled planning forecast that describes weather expected to begin within the next 12 hours and may affect the flow of air traffic in a specific ARTCC area. It gives traffic managers a heads-up about onset times and potential operational effects, such as needed spacing, route adjustments, or capacity changes, so they can plan ahead. AIRMETs are pilots’ weather advisories for moderate conditions, not specifically about traffic-flow planning. SIGMETs warn of significant weather with potential widespread impact, requiring immediate attention rather than horizon planning. Center Weather Advisories are short-notice alerts about weather that could affect operations, but they’re more immediate and not the 12-hour planning horizon described by the MIS.