METAR weather code reference for TS (Thunderstorm (Descriptor))
When used as a descriptor prefix, TS combines with a precipitation type to indicate that the precipitation is occurring with a thunderstorm. For example, TSRA means thunderstorm with rain, TSSN means thunderstorm with snow, and TSGR means thunderstorm with hail. Thunderstorm-associated precipitation is typically heavy and accompanied by turbulence and wind shear.
Here are common ways TS appears in real METAR observations:
TSRATSSNTSGRThese METAR codes are commonly seen alongside TS or describe related weather phenomena:
Liquid precipitation in the form of water droplets greater than 0.5 mm in diameter. Rain is the most commonly reported precipitation type in METARs and can be combined with intensity modifiers (- for light, + for heavy) and descriptors like SH (showers) or FZ (freezing).
Frozen precipitation in the form of ice crystals, most often occurring as snowflakes. Snow significantly reduces visibility and is a primary concern for aircraft icing, runway contamination, and braking action. Often reported with intensity modifiers.
Ice precipitation consisting of balls or irregular lumps of ice with a diameter of 5 mm (about 1/4 inch) or greater. Hail is associated with strong thunderstorms and poses a severe hazard to aircraft, capable of causing structural damage to airframes, windshields, and engines.
Small hail (graupel) or snow pellets less than 5 mm in diameter. These ice pellets form when supercooled water droplets freeze onto snowflakes. Less damaging than full hail but still indicates convective activity and potential for icing conditions.