Description should include the following:
- AIRMETs (Airman's Meteorological Information) report weather events that are considered of operational interest to all types of aircraft. An AIRMET can be issued for such phenomena as moderate icing, moderate turbulence, high surface winds (more than 30 mph), instrument flight rules (IFR) conditions affecting a geographic area, and mountain obscurement.
- A SIGMET (Significant Meteorological Information) advises of non−convective weather that is potentially hazardous to all aircraft.
- SIGMETs are unscheduled products that are valid for four hours. However, conditions that are associated with hurricanes are valid for six hours.