Sigmet 

This product is produced in event of the occurrence or expected occurrence of specified en-route weather and other phenomena in the atmosphere that may affect the safety of aircraft operations. 

Aerodrome Warning 

This product is issued when there is/are concise information of meteorological conditions which could adversely affect aircraft on the ground, including parked aircraft, and the aerodrome facilities and services. 

Windshear Warning 

This product gives concise information on the observed or expected existence of wind shear which could adversely affect aircraft on the approach path or take-off path or during circling approach between or on the runway. When existence of wind shear involving a headwind/tailwind change of 7.5 m/s (15 kt) or more is observed which could adversely affect aircraft on the final approach path or initial take-off path and aircraft on the runway during the landing roll or take-off run a warning is sent and cancelled when below the threshold. 

Volcanic Ash Warning

This product gives concise information on the observed or expected eruption of volcanic ash which could adversely affect safety of aircraft operations