FIG 7-1-5 SIGMET Locations " Contiguous U.S. FIG 7-1-6 Hawaii Area Forecast Locations f. AIRMET. AIRMETs are a concise description of the occurrence or expected occurrence of specified en route weather phenomena that may affect the safety of aircraft operations, but at intensities lower than those which require the issuance of a SIGMET. Meteorology 7-1-15