A layer of relatively warm air aloft, usually several thousand feet above the ground, which suppresses or delays the development of thunderstorms. Air parcels rising into this layer become cooler than the surrounding air, which inhibits their ability to rise further and produce thunderstorms. Sometimes called the lid.
The transport of heat and moisture by the movement of a fluid; In meteorology, the term is used specifically to describe vertical transport of heat and moisture in the atmosphere, especially by updrafts and downdrafts in an unstable atmosphere. Cumulonimbus, towering cumulus clouds and alto-cumulus castellanus clouds are all visible forms of convection. Convection is [...]
The main region of downdraft in the forward, or leading, part of a supercell, where most of the heavy precipitation is.
The altitude at which the air temperature first drops below freezing.
A rotating air mass within a thunderstorm which may produce a tornado, usually 2-6 miles in diameter and often found on the right rear flank of a supercell thunderstorm. On high-precipitation (HP) supercell, the mesocyclone may be found on the front flank. Although strictly speaking a radar term, a supercell may exhibit visual cues indicating [...]
A convective downdraft with an affected outflow area of less than 2 ½ miles wide and peak winds lasting less than 5 minutes. Microbursts may induce dangerous horizontal/vertical wind shears, which can cause property damage.
Thunderstorms are organized in clusters of at least 2-4 short-lived cells. Convergence along the gust front(s) causes new storms to develop every 5-15 minutes
See Multicell Thunderstorm
Occurs when air is forced to rise and cool due to terrain features such as hills or mountains. Orographic lifting may produce clouds and precipitation.
See Single Cell Thunderstorm
Severe weather refers to any dangerous meteorological phenomena with the potential to cause damage, serious social disruption, or loss of human life.
A thunderstorm characterized by a single updraft core and a single downdraft that descends into the same area as the updraft cutting off the thunderstorm inflow which in turn causes the updraft and the thunderstorm to dissipate. Although they may briefly be severe, single cell thunderstorms are short-lived, usually lasting about 1/2 hour to an [...]
A line, either continuous or broken, of active thunderstorms.
See Supercell Thunderstorm
A thunderstorm which contains one quasi-steady to rotating updraft which may persist for several hours. The most dangerous convective storm type.
See Surface-based Convection
A local storm produced by a cumulonimbus cloud and accompanied by lightning and thunder. Types include the Single Cell Thunderstorm, the Multicell Thunderstorm, the Supercell Thunderstorm and the Squall Line.
A small-scale current of rising air. May be marked by the presence of a cumulus cloud if sufficient moisture is present.
A dark, horizontal cloud base often with no visible precipitation beneath it. It typically marks the location of the thunderstorm updraft.
A localized, persistent, often abrupt lowering from a rain-free base. Wall clouds can range from a fraction of a mile up to nearly five miles in diameter, and normally are found on the south or southwest (inflow) side of the thunderstorm in the Northern Hemisphere. When seen from within several miles, many wall clouds exhibit [...]