The Anatomy of the Life of a Supercell

the anatomy of the life of a supercell towering heights of 60,000 feet or more creating balls of ice the size of grapefruit tornadoes potentially greater than a mile wide torrential rain and continuous lightning supercell thunderstorms are the kings of the Great Plains when these storms start in populated area it's up to the Storm Prediction Center National Weather Service media storm spotters and storm chasers to make the public aware supercells occur in two general modes organized and discrete organized storms contain multiple super cells embedded into a parent system each potentially containing heavy rain strong wind and hail these super cells are often outflow dominant but can sometimes produce tornadoes the anvil associated with these systems will have control many miles behind or around the system producing lightning in the stratiform precipitation region organized systems often are preceded by ominous shelf clouds produced by outflow in discrete or semi discrete mode super cells occur in three varieties the first a classic supercell containing a persistent rotating updraft and flow as well as outflow a core consisting of heavy rain and hail and an anvil surrounding the storm with light rain these storms are often characterized by a mesocyclone with boiler plate structure a low precipitation supercell has little to no rain falling around the updraft or plankton line the core can still contain moderate rain and large hail along with light rain small hail the surrounding apple can contain storms in this mode can produce spectacular structure but rarely produce tornadoes high precipitation super cells up drops are partially or completely wrapped in precipitation HP supercells core consists some very heavy rain and hail with light precipitation along the outer edges and under the anvil for a storm to occur three basic ingredients are needed moisture rising and unstable air and a lifting mechanism in the northern hemisphere high pressure pushes air outward and spins clockwise while low pressure draws air in spinning counterclockwise and a typical set up an area of low pressure enters the Plains drawing in cold and dry air from the west and warm and moist air from the South we also get lift in form of warm front cold front dry line and the low pressure system warm air rising is known as convection and is crucial in thunderstorm development lift can also be obtained in several other ways along fronts where warm air is forced upwards causing cloud developer and along sharp dry lines with hot dryer on one side or warm moist air on the other orographic lift occurs when an air mass is forced from a lower elevation to a higher elevation as it moves over rising terrain as the air mass gains altitude it quickly cools adiabatic ly rising the relative humidity to 100% creating clouds lifts can also be obtained through differential heating the Sun heats parts of the earth at different rates this creates different air densities the propensity for air to rise increases with decreasing density an unstable air mass is characterized by warm moist air in the surface and cold dry air aloft air is considered unstable if it continues to rise when given a nudge upward forecasters express the amount of instability by Kate or convective available potential energy often a layer of warm air forms in the cold air aloft this is referred to as an elevated mixing layer or cabbing inversion if the cop is strong enough it will force the Cape to remain below it limiting storm strength or formation altogether the cap can be very important as it causes energy to build beneath it once the cap is broken it is gone and the storm continues to gain strength as the updraft strengthens the storm enters the mature stage a cumulonimbus cloud is born cumulonimbus contain a core of large hail and heavy precipitation the storm will pull in warm moist and flow from a surrounding environment as a cumulonimbus reaches the upper levels of the atmosphere it fans out forming an Amal when sinking air is present beneath the an hole spectacular cloud formations known as maman common misconceptions modest clouds precede severe weather this isn't always the case as they often trail many miles behind the storms first Brazil's Oliver is dangerous the frequent light and intense precipitation cores filled with heavy rain and large hail storms often glow green this indicates the presence of ice hail forms inside the turbulent up drops of thunderstorms the strong updraft keeps our bond very cold our law and causes the ice to grow once the hail stone becomes too heavy for the updraft to support gravity takes over and causes the hail to the lower sometimes so much help to ball the locations resemble scene very large hail can easily be seen on radar and is characterized by a hail spike this storm showed vertically-integrated liquid measuring at 70 decibels relative to Z baseball-sized hail was reported from this storm shortly after this radar reading slow-moving thunderstorms are already saturated ground quickly caused floods to develop flash floods occur within a few minutes or hours of excessive rainfall flash floods can carry vehicles away lift houses off their foundation destroy bridges and tear out trees attempting to cross flooded roadways is extremely dangerous and should never be attempted rapidly rising water can reach heights of 30 feet or more floods are the number one weather-related killer 50% of all flood deaths from vehicle-related six inches of moving water can sweep a car away as thunderstorms encounter wind shear they can begin to rotate when share is a change in speed and direction with height the atmosphere when you have this you end up with a to of rotating air known as a horizontal vorticity tube when an updraft encounters a horizontal vorticity tube it lifts it this causes the development of a mesocyclone which is a persistent rotating updraft a mesocyclone is a vortex of error within a convective storm which rises and rotates around a vertical axis their most often cyclonic associated with a localized low-pressure region within a thunderstorm their baits can be near the surface or elevated in the atmosphere as a general rule the service do point needs to be 55 degrees Fahrenheit for greater for service based storms to occur a dew point of less than this is unfavorable for thunderstorms to become surface based because the moist adiabatic lapse rate has a more stable parcel lapse rate at cooler dew points when dew points at the surface are less than 55 degrees Fahrenheit storms tend to be elevated if an elevated storm encounters more favorable dew points it can transition to a surface based storm service-based storms or more likely to produce tornadoes due to their basins proximity to the ground you and a thunderstorm rising air is known as an updraft while falling air is known as a downdraft supercells contain both very strong updrafts and very strong down drops the up drop of the supercell is tilted with height which directs precipitation away from the region beneath the updraft supercells off blocks precipitation and in such cases is termed arranged freebase this view of a supercell shows the approximate locations of the mid-level winds at 10 to 20,000 feet and the upper-level winds that's 40 to 60,000 feet the strong mesocyclone produces an overshooting top above the anvil its presence indicates an extremely strong updraft Worman flow from the surrounding environment is being pulled into the storm the forward flank downdraft is the outflow from the rain cold air of the storms downdraft the rear flank downdraft is air from the loft that is transported down to the surface from colliding with the storm the flinging line has produced by convergence along an outflow boundary extending from the storm the wall cloud is located in the updraft region of a supercell tornadoes can form at this base the rotating updraft acts as an obstruction to mid upper level flow as high pressure builds up wind of the storm air begins to sink forming RFD on the backside of the supercell RFD can arrive at the surface warmer than surroundings due to 80 about it warming in the absence of precipitation and evaporative cooling properties of RFD have an impact to whether or not a tornado forms the mid-level mesocyclone of intense super cells is strong enough to wrap precipitation around the updraft creating a characteristic oak echo the presence of a hook echo does not mean a tornado is occurring or will develop but signifies a process important in tornado genesis supercell tornadoes occur in the hook area velocity products show wind speed and direction this couplet captured during the Joplin tornado shows classic strong rotation the values and this couple are out in the number obtained is the relative wind speed they wallcloud in lowering rotating cloud base where a humid rain cold air from the storms downdraft is drawn into the updraft its presence is an indication of a low-level mesocyclone from which a tornado develops not all wall clouds produce tornadoes ones that do are persistent for 10 to 20 minutes before tornado formation and also exhibit persistent rotation as this real-time video shows strong employees of at least 35 miles-per-hour are usually observed near torn attic wall clouds often the bass will appear laminar or smooth prior to tornado Genesis the wall cloud will exhibit rapid vertical motion pulling up small cloud fragments or Scud clouds prior to producing a funnel in funnel cloud is a funnel-shaped cloud condense water droplets associated with a rotating column of Wynn thinks of a cloud now reaching the surface the tornado is a violently rotating column of air in contact with the ground and the base of a storm the United States has the highest number of tornado occurrences with an average of over 1,000 each year tornadoes have been reported in every scene in the US wind speeds in a tornado can exceed 300 miles per hour for a tornado to develop a rotating column of air rushing upward must be present on the backside of the tornado there needs to be an air mass falling this error must be at a nearly perfect temperature if it's to hold it has the tendency to choke off the thunderstorm because cold air stabilizes the atmosphere as air flows out as it encounters the surface striking the inflow when the inflow has a narrower path to go through it becomes accelerated tornadoes come in many varieties the majority are weaker bus just a handful of minutes while others grow to become violent and capable of remaining on the ground for long durations lofting debris in their path tornadoes are often comprised multiple vortices these suction vortices are often violent tornadoes can remain stationary or tear across the landscape at speeds in excess of 60 miles per hour an indicator of violence is a horizontal vortex which snakes our from the tornado cyclic supercells can produce families of tornadoes as their associated mesocyclones are cut off or occluded by RFD consider this radar sequence on the cyclic supercell notice the debris ball on the end of the hook which indicates a strong tornado is lofting to breed the tornado moves southeast along with its parent storm this is typical of tornado tracks the rear flank downdraft is now wrapping around the tornado this causes the tornado to change direction as it separates from the parent rotation within the storm the RFD has now completely cut off the tornado from Worman flow the tornado has included as it moves into the ring and dissipates a new mess of Cyclone is forming and will go on to produce another tornado these types of super cells continue to cycle and go on to produce tornado after tornado after tornado tornadoes often become rapid precipitation limiting their visibility compounding an already dangerous situation to obtain a better view of a rain rap tornado storm chasers placed themselves in a region of the storm some call of bears gauge this involves placing themselves and the notch of the hook of a supercell from here risky potentially fatal maneuvered multiple slices by sub chasers where they drive across the ring our home and an attempt to achieve a dangerously close view of the tornado this places them in a precarious position should the storm or tornado change direction on average about 60 people are killed by tornadoes every year in the United States often observers cannot differentiate between a rain rap tornado and a heavy rain curtain until the tornado is near their location many motorists have been killed by driving directly into rain wrap tornadoes when encountering a storm on a day there is a possibility of tornadoes beware of them being rain wrapped as a storm weakens and it becomes outflow dominant this will cause a tornado to dissipate or rope out rotation will cease the updraft weakens and the storm will drop its precipitation for the storm is entering it's dissipating stage you now flow dominant storms contain straight-line winds that can still cause significant damage furthermore an outflow boundary from a dying storm can act as a source of lift possibly igniting new super cells outflow boundaries can enhance the level Scherrer some strong tornadoes have been known to utilize outflow boundaries to strengthen as colder outflow pushes into the warm air ahead of a storm dramatic shelf clouds can form these clouds can appear ominous but tornadoes are unlikely to form in their presence outflow winds can pick up large amount dust dirt causing gust Nadeau's and habu large-scale straight-line wind storms such as de ratios can be as intense as some tornadoes supercells can form any time of the day or night with all hazards possible including dangerous lightning large hail strong tornadoes thank you for watching the anatomy of the life of the supercell you

Channel: Twister Hunter

Views: 215,169

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Id: 7W_s32dDgHY

Length: 30min 24sec (1824 seconds)

Published: Wed Sep 21 2016