Base Reflectivity is the default NEXRAD weather radar image. Taken from the lowest (½° elevation) slice, it is the primary image.
The average velocity of everything in the volume of NEXRAD weather radar beam.
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 height above ground of the center of the radar beam using the tilt, or scan, that contains the highest elevation where reflectivities greater than 18 dBZ can be detected.
A rapid and extreme flow of high water into a normally dry area, or a rapid water level rise in a stream or creek above a predetermined flood level, beginning within six hours of the causative event
Issued to inform the public, emergency management, and other cooperating agencies that flash flooding is in progress, imminent, or highly likely.
Issued to indicate current or developing hydrologic conditions that are favorable for flash flooding in and close to the watch area, but the occurrence is neither certain or imminent.
Any high flow, overflow, or inundation by water which causes or threatens damage.
The altitude at which the air temperature first drops below freezing.
Precipitation falling from a cumulonimbus cloud in the form of pellets or balls of ice greater than 5mm in diameter. Hailstones are usually composed of concentric layers of clear ice and compact snow.
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
Precipitation that falls to earth in drops more than 0.5 mm in diameter.
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.
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.
Air that is able to rise easily, and has the potential to produce clouds, rain, and thunderstorms.