Weather Glossary – T


TCU – Towering Cumulus

TEMPERATURE – a measure of the warmth or coldness of an object or substance with reference to a standard value.

THERMAL- Small rising column of air due to surface heating.

THERMAL RIDGE or THERMAL TROUGH– A ridge of warmer temperatures or a trough of colder temperature.

THERMODYNAMICS– In reference to the (in)stability of the atmosphere. Important thermodynamic information includes lapse rates, CAPE, changes in temperature / moisture with height, and cap strength.

THUNDER- The sound wave produced as a lightning stroke heats the air causing it to rapidly expand.

THUNDERSTORM (TS, TSRA, TSTM) – A shower accompanied by thunder. It is always accompanied by lightning and thunder, and occasionally by strong gusty winds, hail, and or heavy rain.

TORNADO – A violent rotating column of air, usually forming a pendant from a cumulonimbus cloud with the circulation reaching the ground. It nearly always starts as a funnel cloud and may be accompanied by a loud roaring noise. On a local scale, it is the most destructive of all atmospheric phenomena.

TRACE -Precipitation amounts less than 0.01″.

TRADE WINDS – Persistent tropical winds that blow from the subtropical high pressure centers towards the equatorial low.

TROPICAL DEPRESSION – Tropical mass of thunderstorms with a cyclonic wind circulation and winds between 20 and 34 knots.

TROPICAL DISTURBANCE – An organized mass of tropical thunderstorms, with a slight cyclonic circulation, and winds less than 20 knots.

TROPICAL STORM – An organized cyclone in the tropics with wind speed between 35 and 64 knots.

TROPOSPHERE– The lowest layer of the atmosphere where the temperature decreases with height. Most of earth’s weather occurs in this layer.

TROUGH -An elongated area of low pressure at the surface or aloft.

TSUNAMI – An ocean wave generated by a submarine earthquake, volcano or landslide. (Also known as a seismic seawave, and incorrectly as a tidal wave).

TURBULENCE– Disrupted flow in the atmosphere that produces gusts and eddies.

TURBULENCE – Disrupted flow in the atmosphere that produces gusts and eddies.

TWEAK– To change slightly. Often in reference to slightly changing MOS output or any other form of model guidance.

TYPHOON – A hurricane that forms in the Western Pacific Ocean.