Local warning techniques, such as vertically integrated liquid (VIL) techniques are only briefly mentioned, but the most widely used and accepted warning techniques are included in detail. The ideas presented in this paper are not meant to be the definitive study on the subject of radar techniques for warnings, but are only meant to be guidelines on the subject. Our pages contain various quotes with which our editorial team does not always agree.TECHNIQUES FOR ISSUING SEVERE THUNDERSTORMĪND TORNADO WARNINGS WITH THE WSR-88D DOPPLER RADARĪBSTRACT This paper reviews conventional radar warning guidelines and compiles techniques for the decision making process in issuing Doppler radar based severe thunderstorm and tornado warnings. See also: Radiation belts, North atlantic oscillation, Cold high, Temperature-humidity index, Rain shower HOW DOES RADAR DETECT PRECIPITATION PARTICLES?Ģ39. The Level II data is available in 0.5 dBZ increments, while the Level III reflectivity data is only available in 5.0 dBZ increments.Ģ35. It also allows the ability to locate certain weather phenomena such as gust fronts and es that can be hard to see with the Level III data. Radar signature generally similar to a, except that the hook shape is not as well defined. Classic supercell tornadoes are often un-obstructed from view if being viewed from the backside of the storm. The hook is best observed in the reflectivity field.ĬLASSIC SUPERCELL - A supercell with "text-book" like features such as a well-defined on a radar scope and the precipitation core downwind of the wall cloud and rain free storm base. Tornadoes are often located at the center of a hook-shaped echo on the southwest side of thunderstorms. Locating Tornadoes es and velocity couplets Radar characteristics often (but not always) include a, bounded weak echo region ( BWER), V-notch, mesocyclone, and sometimes a TVS. Penetrating TopSame as Overshooting Top a dome-like protrusion above a thunderstorm anvil, representing a very strong updraft and hence a higher potential for severe weather with that storm. Pendant EchoRadar signature generally similar to a, except that the hook shape is not as well defined. Homologous FlaresIn solar-terrestrial terms, solar flares that occur repetitively in the same active region, with essentially the same position and with a common pattern of developmentHook EchoA radar reflectivity pattern characterized by a hook-shaped extension of a thunderstorm echo. Hook (or ) - a radar reflectivity pattern characterized by a hook- or crescent-shaped extension of a thunderstorm echo, usually in the right-rear part of the storm (relative to its direction of motion). Horizontal vorticity is most important in the PBL ( low-levels of atmosphere). Vorticity caused by a change in wind direction or wind speed with height is termed horizontal vorticity (the spin is in relation to a horizontal axis). However, es and tornadoes do not always accompany each other. It usually appears on the south side of a severe thunderstorm cell in the presence of a mesocyclone.Ī radar reflectivity pattern observed in a thunderstorm, appearing like a fish hook and indicating favorable conditions for tornadic development. : a distinct radar pattern that often indicates the presence of a severe thunderstorm and perhaps tornado. This hook-shaped extension of a thunderstorm echo, usually appears in the right-rear part of the storm (relative to its direction of motion). A radar reflectivity pattern characterized or observed in a thunderstorm, that appears like a fish hook. Since the mesocyclone has counterclockwise winds, the reflectivity signature of a will have a cyclonically shaped hook. It is a signature produced by precipitation held aloft that wraps around the mid-level mesocyclone. Not all observed es accompany tornadoes, or vice-versa, but seeing a on radar is a good indication that a tornado may have formed, or may form quickly. A hook often is associated with a mesocyclone, and indicates favourable conditions for tornado development.Ī signature on radar, associated with a tornadic rotation that appears as a hook-like extension from a strong thunderstorm. (or hook) A radar reflectivity pattern characterized by a hook-shaped extension of a thunderstorm echo, usually in the right-rear part of the storm (relative to its direction of motion). Appearing like a fishhook turned in toward the east, the hook echo is precipitation aloft around the periphery of a rotating column of air 2-10 miles in diameter. Hook Echo - A radar pattern sometimes observed in the southwest quadrant of a tornadic thunderstorm. Weather radar signature indicating tornadic circulation in a supercell thunderstorm.
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