Active in-flight weather hazard advisories (SIGMETs and AIRMETs) from the NOAA Aviation Weather Center. Returns current advisories over a lookback window (1-24h), optionally filtered by hazard (CONVECTIVE, TURB turbulence, ICE icing, IFR, MTN OBSCN mountain obscuration, ASH volcanic ash). Each advisory carries the issuing office, type (SIGMET/AIRMET/OUTLOOK), hazard, severity, valid-from/to times, affected altitude band (feet MSL), movement (direction/speed), and the raw text bulletin. Keyless, public-domain (NOAA). The active-hazard layer aviation agents need — distinct from aviation.metar (station conditions) and aviation.taf (forecasts). Not for navigation.