Trough - A sharpened zone of cyclonic wind change usually associated with a zone of lower pressure. Troughs can occur at the surface up to around 30,000 ft up in the atmosphere. Deep troughs in the mid to upper levels tend to be associated with surface frontal boundaries and surface low pressure systems. Inclement weather can be expected when a trough moves through a particular area.

Indian Summer - A period of unseasonably warm and sunny weather that occurs from late September to mid November. In parts of the country, the first killing frost of the season must occur before a late autumn warm spell can be coined 'Indian Summer'.

Warm Air Advection - A transport of warm air that occurs due to winds blowing from a region of warmer air into an area of cooler air. When warm air advection occurs, the warmer air will rise over the cooler air, due to the higher density of cold air. Meteorologists look for regions of strong warm air advection when diagnosing where air will be rising in the atmosphere.

Drought - An extended period of abnormally dry weather that creates shortfalls in the amount of surface and/or subsurface water. Droughts have major impacts on agriculture and can have major socioeconomic consequences as well.

Sub-vortices - Small areas of intense rotation located within a type of tornado called a multi-vortex tornado. These spinning whirls can be thought of as individual tornadoes that are mixed within the main tornado. These are also sometimes referred to as suction vortices and the winds within them can be 100 mph stronger than the main body of the tornado. These can explain why the damage path in a tornado can vary greatly.

Mesosphere - The mesosphere is a layer of the Earth's atmosphere located at an altitude of 30 to 50 miles above the Earth's surface. It is the layer where most meteors burn up upon entering the atmosphere. Because of this, there is a high concentration of iron and other metals in the mesosphere.

Turbulence - Any irregular or disturbed flow in the atmosphere caused by eddies and vertical air currents. Regions of the atmosphere that are characterized by turbulence will often be found in the vicinity of frontal boundaries. Thunderstorms produce the most severe turbulence due to the intense upward and downward vertical air currents that occur in the vicinity of them.