What is an unscheduled weather advisory issued for ATC used to alert pilots of existing or anticipated adverse weather conditions within the next two hours?

• A. HIWAS
• B. SIGMET
• C. CWA
• D. PIREP

Answer: (C)

Center Weather Advisory is an unscheduled weather advisory issued to air traffic control to alert pilots about weather conditions existing or expected within the next two hours. It serves to quickly relay potentially hazardous conditions that are not severe enough to meet SIGMET criteria but still require timely awareness for flight planning and routing. CWAs are issued by weather forecast offices and specifically used by ATC to inform pilots through controllers. HIWAS provides continuous weather information, including SIGMETs, but is not the targeted, time-limited advisory used to warn about imminent conditions. SIGMETs warn of significant, more severe phenomena and are not limited to a two-hour window, while PIREPs are pilot reports, not issued advisories.