Supercells are often accompanied by large hail and damaging winds, but sometimes they spawn tornadoes. These storms are the most intense type of thunderstorm. The tornado caused major damage in the town and killed three people. The National Severe Storms Laboratory (NSSL) said fewer than 20% of all supercell thunderstorms produce tornadoes. A rotating updraft is a key to the development of a supercell, and eventually a tornado. Supercells have a distinct appearance on Doppler radar, which often features a so-called hook echo on the lower-left portion of the storm. Tornadoes come from mainly two types of thunderstorms: supercell and non-supercell. The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. (Note: Other thunderstorms active in surrounding areas were removed to provide clarity on the track of the supercell storm. A long-lived supercell thunderstorm tracked nearly 300 miles in three states and likely spawned multiple tornadoes on Wednesday, including a deadly twister in Texas. The general track of the supercell from when it began to form in eastern Texas to when it began to dissipate near the border between Louisiana and Mississippi. When tornadoes are spawned by supercells, they are near the hook echo on radar. Fewer than 20% of supercells produce tornadoes, but the majority of all tornadoes occur in supercells. Wednesday's supercell first showed signs of developing in east Texas during the mid-afternoon hours about 3 p.m. CDT. "What makes a supercell unique from all other thunderstorm types is that it contains a deep and persistent rotating updraft called a mesocyclone," the NWS forecast office in Amarillo, Texas, states. The National Weather Service will survey areas where this supercell tracked to determine how many tornadoes it produced. Since it was ongoing for more than four hours, it's classified as a long-lived supercell, according to a 2005 study. These storms originate in unstable air that is paired with as wind shear, or winds changing direction at various altitudes in the atmosphere. A supercell thunderstorm is characterized by a sustained and powerful rotating updraft (rising air). ), (National Weather Service - Norman, Oklahoma), National Severe Storms Laboratory (NSSL) said. Here's another animation of this supercell's hook echo as it crossed into Louisiana from Texas. We recognize our responsibility to use data and technology for good. The best-organized supercells may spawn multiple tornadoes, some of which can stay on the ground for a lengthy period of time. Severe Weather 101 Types of Tornadoes. Radar image of a supercell in southwestern Oklahoma on Nov. 7, 2011. A supercell thunderstrom in Oklahoma. Supercells are often isolated from other thunderstorms, and can dominate the local weather up to 32 kilometres (20 mi) away. supercell (in atmospheric science) A weather system with strong rotating clouds that is fueled by a long-lasting updraft of air. A supercell thunderstorm tracked hundreds of miles from Texas to near the border between Louisiana and Mississippi on Wednesday. Second Sunday of Deadly Southern Tornadoes and Storms Lashes Deep South (PHOTOS). tornado A violently rotating column of air extending from the ground to a thunderstorm above. The hook echo and hail core are labeled. A supercell is a thunderstorm characterized by the presence of a mesocyclone: a deep, persistently rotating updraft. The same rapidly rising air motions that form the thunderstorm turn this horizontal rotation into a vertical rotation, which can then be spectacularly evident in the circular striations, or layers, visible in the cloud structure of the supercell. The precipitation can sometimes obscure the storm's structure, including wall clouds and tornadoes. Low-pressure systems in various regions of the world can spawn supercell thunderstorms when atmospheric conditions are ripe. You can see this in the radar animation below, when a strong tornado was ongoing near the hook echo in Onalaska, Texas. They tend t… The tornado caused major damage in … You can see the general track of the supercell in the graphic at the top of this article, that shows it covered a distance of nearly 300 miles, or possibly more, from when it first began to develop to when it weakened. However, supercells are responsible for spawning the vast majority of all tornadoes – violent ones in particular – NSSL added. Wednesday's supercell had this so-called hook echo along the majority of its path. Such systems can generate hail — or even tornadoes.
Of the four classifications of thunderstorms (supercell, squall line, multi-cell, and single-cell), supercells are the overall least common and have the potential to be the most severe.
Image courtesy of NSSL/NOAA. As the name implies, an LP supercell is accompanied by lighter amounts of precipitation – rain or hail. That hook echo appendage extends southward from the thunderstorm's main core, where large hail and heavy rain are typically located. Thunderstorm - Thunderstorm - Supercell storms: When environmental winds are favourable, the updraft and downdraft of a storm become organized and twist around and reinforce each other.
updraft A … This type of supercell is easy to spot in the Plains because there is a clear view of the structure. Classic supercells appear as individual storms like we showed earlier, but sometimes can be embedded within a line or cluster of thunderstorms. The term supercell is used by meteorologists to describe a breed of long-lasting thunderstorms that rotate and are accompanied by dangerous weather conditions, including large hail, damaging winds and sometimes tornadoes. For this reason, these storms are sometimes referred to as rotating thunderstorms. Take control of your data: © Copyright TWC Product and Technology LLC 2014, 2020. From there, it tracked for several hours into Louisiana before weakening as it began to cross into Mississippi before midnight. This story does not necessarily represent the position of our parent company, IBM. They can also occur in landfalling tropical storms and hurricanes. Tornadoes obscured by heavy precipitation are typically known as "rain-wrapped.". Supercell thunderstorms are sometimes referred to as low precipitation (LP) or high precipitation (HP). Supercell Tornadoes. The result is a long-lived supercell storm. A common combination supportive of supercells often found in the Plains states is a southerly or southeasterly wind near ground level and a southwesterly or westerly wind higher in the atmosphere. HP supercells contain heavier concentrations of rain and hail. This combination of changing wind directions and speeds creates a horizontal rolling motion in the lower atmosphere. A supercell thunderstorm tracked hundreds of miles from Texas to near the border between Louisiana and Mississippi on Wednesday. When supercells develop in a volatile atmospheric environment, they can survive for dozens or even hundreds of miles over multiple hours.
There were multiple additional reports of tornadoes along the path of this supercell, including near Jasper, Texas, and south of Alexandria, Louisiana.
More research is underway to discover why some of these rotating thunderstorms are accompanied by tornadoes while others are not. Tornadoes that come from a supercell thunderstorm are the most common, and often the most dangerous. Wednesday's supercell likely spawned more than one tornado, including a deadly one in Texas. A somewhat recent example is a supercell in southwestern Georgia on Jan. 22, 2017, which spawned a tornado in progress for 72 minutes along a 70-mile-long path.