Base velocity function – a radar function that shows wind speed and direction, which can indicate when there is rotation in a storm
Chaser convergence – phenomenon in which a high number of storm chasers, many of them amateur, swarm to one area and create traffic jams while storm chasing
Condensation funnel – a rotating column of condensed water droplets that extends from the base of a cloud but has not yet reached the earth’s surface; also called a funnel cloud
Cone tornado – refers to the shape of a tornado when it is wide at the top and narrow at the bottom
Convective Outlook – a categorical multiday forecast released by the Storm Prediction Center that depicts severe weather threat levels
Doppler radar – a radar system that can detect the motion and intensity of precipitation, which helps meteorologists analyze storm structure
Enhanced Fujita Scale – a rating system that measures the intensity of a tornado on a scale of 0-5 based on the damage it causes, seen as EF0, EF1, EF2, EF3, EF4, and EF5, with EF5 being the most intense
Flash flood watch – a notice released by the National Weather Service to indicate that conditions in a certain area are favorable for flash flooding
Flash flood warning – a notice released by the National Weather Service to indicate that there is a flash flood occurring or imminent in a particular area
Hook echo – a hook-shaped radar signature during some storms that indicates counter-clockwise winds wrapping precipitation around a rotating column; it often denotes a tornado-producing storm
Inflow bands – clouds that gather low-level air moving toward a thunderstorm
Long-track tornado – a tornado that stays on the ground for at least twenty-five miles
Mammatus clouds – pouch-like cloud structures formed in sinking air; they are associated with thunderstorms
Particularly Dangerous Situation (PDS) Tornado Watch – a notice released by the Storm Prediction Center at least two hours before the first tornado to indicate that conditions will be favorable for multiple tornadoes or a particularly severe tornado; the purpose is to forewarn the public about probable severe weather and provide storm chasers time to prepare in advance
Rope tornado – refers to the shape of a tornado when it is narrow and rope-like from top to bottom
Stovepipe tornado – refers to the shape of a tornado when it is the same width at the top and the bottom
Subvortex – an additional tornado that rotates near a main vortex
Supercell – a thunderstorm defined by the presence of a rotating updraft called a mesocyclone
Tornadic waterspout – a tornado that forms over a body of water or travels from land to water
Tornado – a mobile, violently rotating vortex of air that touches the ground
Tornado warning – a notice released by the National Weather Service to indicate that tornadoes are occurring or imminent in a particular area
Updraft – an upward moving and often rotating current of air that helps form thunderstorms
Wall cloud – an abrupt and low-hanging cloud lowering from a larger cloud base; it marks the area of strongest updraft and is an indicator of rotation that can form a tornado
Wedge tornado – refers to the shape of a tornado when it is wider at the bottom than it is tall