chapter 19
At what time of day are tornadoes most common?
Late afternoon.
In which months of the year are tornadoes most common?
Spring: particularly late April, May and early June.
The process of tornadogenesis associated with tilting of the horizontal rotation at the periphery of the rear flank downdraft is believed to be the most common way tornadoes form
True
The rotating portion of a supercell thunderstorm is called the mesocyclone.
True
Tornado Alley is aligned with a typical orientation of strong cold fronts as they move across the central U.S. in spring and early summer
True
Tornadoes are more common in the southeast U.S. (e.g., Alabama & Mississippi) in early spring, central U.S. in late spring to early summer, and in the Northern Plains (e.g., Dakotas) in mid-summer.
True
Describe typical tornado characteristics such as width, range of wind speeds, and time on the ground.
Width: 50 to 800 meters (150 ft to 0.5 mile); range of wind speeds: 57 kts to over 174 kts (65 mph to over 200 mph); time on ground: minutes to over an hour
A tornado rips through your college next spring (luckily on a holiday when no one is on campus). The tornado destroys brick buildings and leaves no bricks or debris on the foundations. What time of day would it most likely have occurred? (a) 6:00 A.M. (b) 12:00 P.M. (c) 6:00 P.M. (d) 12:00 A.M.
(c) 6:00 P.M
Which statement best describes a tornado family? (a) A cluster of tornadoes from nearby storms (b) A large tornado surrounded by smaller, less violent tornadoes (c) Multiple tornadoes that develop from the same supercell thunderstorm (d) A pair of tornadoes where one is rotating cyclonically and the other anticyclonically
(c) Multiple tornadoes that develop from the same supercell thunderstorm
Why is it not a good idea to seek shelter under a highway overpass when a tornado is approaching?
Air may be funneled through the narrow
What are typical path lengths of EF0 and EF1 tornadoes? of EF4 and EF5?
Averages are: EF0: 1.9 km EF1: 4.2 km EF4: 43.8 km EF5: 57.2 km
Why can it be difficult to assign an EF-scale rating to a tornado?
If a violent tornado strikes no structures, there is no basis to assign it a high EF-scale rating.
Data provided by the WSR-88D Doppler network allows meteorologists to issue advanced tornado warnings, often minutes before an actual tornado touchdown occurs.
True
What is a typical ratio of the diameters of a mesocyclone and a tornado?
Mesocyclone: 5 km, Tornado: 500 m. About 10/1.
If caught outside in the path of a tornado, what should a person do?
Move away from objects, get as low as possible, preferably in a ditch, cover your head with your hands.
During the decay stage of a long-lived tornado, the tornado vortex takes on the shape of a rope.
True
About 75 percent of all tornadoes occur in the United States.
True
What data would be best to identify a landspout circulation? (a) soundings (b) radar reflectivity (c) radar radial velocity (d) visible satellite imagery (e) infrared satellite imagery
c) radar radial velocity
Which of the following was not a problem with the original Fujita scale? (a) Scale ranking was always based on damage only. (b) Rankings overestimated the wind speeds in more violent tornadoes. (c) The original damage assessment guidelines were not detailed and specific. (d) Damage assessment did not take into account structural integrity of buildings
(a) Scale ranking was always based on damage only.
The National Weather Service issues a tornado watch when __________and tornado warning when __________. (a) conditions are favorable for tornado formation; a tornado is believed to be present in a warning area (b) a tornado is believed to be present in a warning area; conditions are favorable for tornado formation (c) emergency management personnel should warn the public to take cover immediately; emergency management personnel should abandon the warning effort and take cover themselves. (d) debris from a tornado is expected to impact an area; the debris is actually observed and is an obstruction to traffic
(a) conditions are favorable for tornado formation; a tornado is believed to be present in a warning area
If the Doppler radar detects a mesocyclone signature, approximately how long does it take forecasters to identify its position, track its movement and forecast its future location? (a) seconds (b) minutes (c) about a half hour (d) This is not possible yet.
(a) minutes
Which choice lists vortices from smallest to largest? (a) suction vortex, tornado, mesocyclone, hurricane, extratropical cyclone (b) suction vortex, mesocyclone, tornado, extratropical cyclone, hurricane (c) tornado, suction vortex, hurricane, mesocyclone, extratropical cyclone (d) extratropical cyclone, hurricane, mesocyclone, suction vortex, tornado (e) mesocyclone, suction vortex, hurricane, tornado, extratropical cyclone
(a) suction vortex, tornado, mesocyclone, hurricane, extratropical cyclone
What is tornadogenesis? (a) the formation of a tornado (b) the formation of a funnel cloud (c) the dust and debris created from a tornado (d) the part of a tornado in contact with the ground (e) the first book of the tornado bible
(a) the formation of a tornado
This is issued when conditions are favorable for tornado formation. (a) tornado watch (b) tornado warning (c) tornado advisory (d) severe thunderstorm watch (e) severe thunderstorm warning
(a) tornado watch
. In a supercell thunderstorm, a tornado develops on the boundary between what parts of the thunderstorm? (a) updraft-anvil (b) updraft-rear flank gust front (c) wall cloud-anvil (d) rear flank downdraft-forward flank downdraft (e) forward flank downdraft-hailshaft
(a) updraft-rear flank gust front
An EF1 tornado would be _________ whereas an EF5 tornado would be ________ . (a) weak; devastating (b) strongest; weakest (c) forward moving at 10 knots; forward moving at 50 knots (d) rapidly rotating: 100 knots; rapidly rotating: 500 knots (e) on the ground for 1 hour; on the ground for 5 hours.
(a) weak; devastating
What is the approximate mean path length for an EF5 tornado? (a) 5 miles (b) 35 miles (c) 100 miles (d) 500 miles
(b) 35 miles
During which months are tornadoes most common in the United States? (a) February, April, May (b) April, May, June (c) June, July, August (d) August, September, October (e) October, November, December
(b) April, May, June
During which months do the strongest tornadoes typically occur in the United States? (a) February, April, May (b) April, May, June (c) June, July, August (d) August, September, October (e) October, November, December
(b) April, May, June
What is the maximum ranking of a tornado on the EF-scale? (a) EF3 (b) EF5 (c) EF7 (d) EF10
(b) EF5
Which U.S. state has the most tornadoes per 10,000 square mile area? (a) Texas (b) Florida (c) Illinois (d) Nebraska (e) Oklahoma
(b) Florida
. The National Weather Service has just issued a tornado warning that includes your city. You are the manager of a movie theater, and there is a show with 500 people attending. What should you do? (a) Let the show go on as planned but pay attention to weather reports for additional information. (b) Interrupt the show and take the crowd to the basement of the building or an interior room in an orderly manner. (c) Stop the show and send everybody home. (d) Grab your camcorder, go outside and film the impending tornado for the theater. (e) Scream and call your mother for advice
(b) Interrupt the show and take the crowd to the basement of the building or an interior room in an orderly manner.
What is the current controversy concerning the Tri-State Tornado of 1925? (a) The number of people injured and killed is in dispute, as is the total amount of property damage. It appears that official records have been lost and scientists cannot agree on damage totals for the storm. (b) The official path length of the tornado is listed as 219 miles, however, many scientists today believe that it was not a single tornado, but rather a family of tornadoes that produced the damage and caused the injuries and fatalities. (c) The storm that produced the tornado did not show up on the radar imagery as the classic "hook echo" and therefore forecasters were not able to provide advance warnings. The citizens of the rural areas did not feel that this was a justified reason for not issuing warnings and filed a suit. (d) There is no controversy surrounding the Tri-State Tornado, therefore (a), (b), and (c) are all incorrect.
(b) The official path length of the tornado is listed as 219 miles, however, many scientists today believe that it was not a single tornado, but rather a family of tornadoes that produced the damage and caused the injuries and fatalities.
What typically happens to a tornado immediately after vortex breakdown occurs? (a) The tornado dissipates. (b) The tornado becomes very large. (c) The tornado decreases in intensity. (d) The tornado forms a rope-like shape. (e) None of the above are correct.
(b) The tornado becomes very large
On what type of weather product would you be able to identify the mesocyclone signature associated with a tornadic supercell? (a) sounding (b) radar radial velocity (c) radar reflectivity (d) visible satellite (e) infrared satellite
(b) radar radial velocity
On what type of weather product would you be able to identify the tornado vortex signature associated within a tornadic supercell? (a) sounding (b) radar radial velocity image (c) radar reflectivity image (d) visible satellite image (e) infrared satellite image
(b) radar radial velocity image
What is a typical diameter of a mesocyclone? (a) 0.5 miles (b) 1 mile (c) 3 miles (d) 10 miles (e) 100 miles
(c) 3 miles
Tornadoes do not develop from all mesocyclones. What is the current estimate, based on statistics, of the percent of supercell thunderstorms with distinct mesocyclone signatures on radar that actually produce a tornado? (a) 1 percent (b) 5 percent (c) 30 percent (d) 50 percent (e) 75 percent
(c) 30 percent
Two features observed with radar that meteorologists use to identify the location where a tornado may be occurring are: (a) high (cold) cloud tops on the infrared channel and a sharp, clear/cloud boundary on the water vapor channel. (b) strong vertical shear on the sounding and a weak inversion in the lower troposphere. (c) a hook echo in the radar reflectivity field and a tornado vortex signature in the radar radial velocity field. (d) extremely high reflectivity and cloud tops above 10 kilometers. (e) None of the above are correct
(c) a hook echo in the radar reflectivity field and a tornado vortex signature in the radar radial velocity field.
Based on tornado climatology, what time of day represents the climatological maximum for tornado events? (a) early morning (b) late morning or around noon (c) late afternoon or early evening (d) late evening to around midnight (e) middle of the night
(c) late afternoon or early evening
The __________ tornadoes tend to stay on the ground the __________ amount of time. (a) largest; shortest (b) weakest; longest (c) most severe; longest (d) most severe; shortest
(c) most severe; longest
If a supercell is producing a tornado, the tornado would be found in the cusp of the "hook echo". What weather product would a meteorologist examine to observe the hook echo? (a) visible satellite image (b) infrared satellite image (c) radar reflectivity image (d) sounding (e) sea level pressure analysis
(c) radar reflectivity image
. This is issued when conditions are right for the development of thunderstorms containing strong winds, hail, frequent lightning, heavy rain and possibly tornadoes. (a) tornado watch (b) tornado warning (c) severe thunderstorm watch (d) severe thunderstorm warning (e) severe thunderstorm advisory
(c) severe thunderstorm watch
What region of the U.S. has the largest number of reported tornadoes? (a) the Northeast (b) the Great Lakes (c) the Great Plains (d) the Desert Southwest (e) the central Atlantic Coast
(c) the Great Plains
During what time of day are tornadoes in the U.S. most common? (a) ~ noon (b) ~ 3:00 P.M. (c) ~5:00 P.M. (d) ~8:00 P.M.
(c) ~5:00 P.M.
What products and methods can meteorologists use to detect tornadoes? (a) WSR-88D Doppler radar data. (b) information from volunteer storm spotters. (c) Animations of GOES high resolution satellite data. (d) (a) and (b) are both correct. (e) (a) and (c) are both correct, (c) is incorrect.
(d) (a) and (b) are both correct, (c) is incorrect.
What is the current average lead time for tornado warnings? (a) 0 minutes (no lead time) (b) 2 minutes (c) 6 minutes (d) 12 minutes (e) 27 minutes
(d) 12 minutes
. During what decade was the National Weather Service Doppler radar network (WSR-88D) made operational? (a) 1940s (b) 1960s (c) 1970s (d) 1990s (e) 2000s
(d) 1990s
When is a strong tornado most likely to occur? (a) 3:00 A.M., mid-May (b) 3:00 A.M., mid-October (c) 5:00 P.M., mid-October (d) 5:00 P.M., mid-May (e) 9:00 P.M., mid-June
(d) 5:00 P.M., mid-May
What percent of world-wide tornadoes occur in the United States? (a) 5 percent (b) 25 percent (c) 50 percent (d) 75 percent (e) 100 percent
(d) 75 percent
Which statement(s) about tornadoes is correct? (a) The damage path of a tornado is typically 10 miles wide and 30 miles long. (b) About 75 percent of all tornadoes occur in the United States. (c) Most tornadoes are short lived, lasting only minutes. (d) Only (b) and (c) are correct. (e) (a), (b) and (c) are all correct.
(d) Only (b) and (c) are correct
Which statement about tornadoes is not correct? (a) Tornadoes primarily develop within supercell thunderstorms. (b) Tornadoes can form in thunderstorms along squall lines, near the ends of thunderstorm bow echoes, and within landfalling hurricanes. (c) Tornadoes typically range in width from about 150 ft to a half mile. (d) Wind speeds in a tornado range from 150 mph to over 400 mph
(d) Wind speeds in a tornado range from 150 mph to over 400 mph.
This is issued when a severe thunderstorm is occurring in or near the area. (a) tornado watch (b) tornado warning (c) severe thunderstorm watch (d) severe thunderstorm warning (e) severe thunderstorm advisory
(d) severe thunderstorm warning
. What does the term "mesocyclone" refer to? (a) a very large tornado (b) a high altitude tornado (c) a false alarm tornado warning (d) the rotating region of a supercell thunderstorm (e) None of the above are correct
(d) the rotating region of a supercell thunderstorm
What are "storm spotters"? (a) individual cloud tops that appear on infrared satellite just prior to tornadogenesis (b) the red-colored radar echoes that appear on Doppler radar during tornadic thunderstorms (c) meteorologists who watch the skies through the windows of the National Weather Service office (d) trained volunteer citizens who monitor severe weather conditions from a pre-determined location
(d) trained volunteer citizens who monitor severe weather conditions from a pre-determined location
. These vortices are most commonly observed off coastlines in tropical regions. (a) gustnado (b) dust devil (c) landspout (d) waterspout (e) cold air funnel
(d) waterspout
On what do forecasters base the issuance of a severe thunderstorm warning? (a) radar (b) storm spotter reports (c) information from the public (d) Both (a) and (b) are correct. (e) (a), (b) and (c) are all correct.
(e) (a), (b) and (c) are all correct.
On what do forecasters base the issuance of a tornado warning? (a) radar (b) storm spotter reports (c) information from the public (d) Both (a) and (b) are correct, (c) is incorrect. (e) (a), (b) and (c) are all correct
(e) (a), (b) and (c) are all correct.
When was the Fujita scale (F-scale) updated to the Enhanced Fujita scale (EF-scale)? (a) 1970 (b) 1982 (c) 1996 (d) 2000 (e) 2007
(e) 2007
Which statement(s) about tornadoes is (are) true? (a) EF5 tornadoes occur rarely but stay on the ground the longest and cause the most fatalities. (b) The most likely time to observe a tornado would be between 5:00 and 6:00 P.M. during the month of May. (c) Weak tornadoes (EF0 and EF1) are more common than stronger tornadoes (EF4 and EF5) since the conditions to produce these weak tornadoes are often found in supercells. (d) Tornadoes are common in the United States because of its unique geography, including the Rockies to the west, which help cyclones form; the Gulf of Mexico, which provides heat and moisture; and the plains of central Canada, where the cold air originates. (e) All of the above statements are true.
(e) All of the above statements are true.
Which statement is false? (a) Landspouts are generally short-lived. (b) Supercell tornadoes are typically stronger than landspouts. (c) Most tornadoes that occur in California in winter are landspouts. (d) Landspouts develop along a boundary where horizontal wind shear is present. (e) Multiple landspouts can form from the same thunderstorm but there is never more than one landspout present at a given time
(e) Multiple landspouts can form from the same thunderstorm but there is never more than one landspout present at a given time.
Which statement about tornadoes is not correct? (a) Exceptionally strong tornadoes can destroy steel-reinforced structures. (b) Strong tornadoes can throw automobiles over 100 feet. (c) On average, over 1,000 tornadoes are reported in the United States each year. (d) Over the 10-year period ending in 2009, an average of around 56 people have been killed and roughly another 850 injured in the United States annually by tornadoes. (e) Over the 10-year period ending in 2009, tornadoes were responsible for over 20 billion dollars in property losses annually
(e) Over the 10-year period ending in 2009, tornadoes were responsible for over 20 billion dollars in property losses annually
Which statement about tornadoes is true? (a) Tornado alley is located the eastern United States. (b) U.S. tornadoes occur in every season except winter. (c) Tornadoes occur in every state in the contiguous U.S. except California. (d) The United States is second only to Australia for number of tornadoes that occur each year. (e) Regions of the world that have a lot of tornadoes generally have good agricultural production.
(e) Regions of the world that have a lot of tornadoes generally have good agricultural production
A map of the distribution of tornadoes around the world would correspond to: (a) a map of the rural areas because urban areas do not have tornadoes. (b) a map of the world's mobile home parks since these attract tornadoes. (c) a map showing hurricane origin areas because hurricanes are essentially large tornadoes. (d) a map of the central United States because other areas of the world do not have tornadoes. (e) a map of the world's prime agricultural growing areas because thunderstorms provide the water necessary for growth of crops.
(e) a map of the world's prime agricultural growing areas because thunderstorms provide the water necessary for growth of crops
If a tornado is present, where on a radar reflectivity image would the tornado be located? (a) north of the hook (b) near the overshooting top (c) in the rear flank downdraft (d) in the forward flank downdraft (e) coincident with the "debris ball" echo
(e) coincident with the debris ball echo
The annual average number of fatalities due to tornadoes has decreased since the 1950s.
. Better warnings due to storm spotting in the 60s-80s and Doppler radar in the 90s to today.
Can a Doppler radar detect a tornado funnel? Explain.
. Generally no. The cloud droplets in a funnel cloud are too small to detect. Also the funnel is typically much smaller than the pixel size of a single radar pulse volume.
What is the EF-scale? How is an EF-scale rating assigned to a tornado?
. The EF-scale is Enhanced Fujita scale. The damage from a tornado is assessed using Damage Indicators and prescribed tables that allow for the estimation of wind speed ranges based on damage.
What is "vortex stretching"? What physical principle is used to explain vortex stretching?
. Vortex stretching is a process whereby a column of rotating air is elongated so that the rotation velocity of the air is increased. Physical principle: conservation of angular momentum.
Describe conceptually the three different mechanisms that scientists believe lead to tornadogenesis.
1) Tilting of the horizontal rotation along a gust front boundary associated with buoyancy differences between the cool and warm air. If this process occurs under the supercell updraft, it is believed to lead to tornadogenesis. (2) Descent of a stretched vortex tube aloft downward due to the dynamic pipe effect (3) Spin-up of a tornado along the occlusion downdraft interface with the updraft in a manner similar to the way suction vortices form in large tornadoes.
Which statement about tornado safety is false? (a) During a tornado you should seek shelter in the lowest floor in the building in the most interior room. (b) If caught outdoors in your car, you should park under a highway overpass and seek shelter near the girders of the bridge. (c) If no shelter is available and you are in your car, abandon your car and find a lowlying area and lay flat. (d) Put as many walls between you and the tornado as possible. (e) Abandon mobile homes and find stronger shelter or lie in a ditch.
: (b) If caught outdoors in your car, you should park under a highway overpass and seek shelter near the girders of the bridge.
How does a landspout tornado form?
Breakdown of horizontal wind shear creates a series of small vortices along the shear zone. When these vortices develop under an updraft they are stretched into tighter circulations until a landspout forms.
What tools are available for meteorologists to detect tornadoes?
Doppler radar is the primary tool used to detect tornadoes.
A tornado is a violently rotating column of air that may or may not be in contact with the ground.
False
An EF0 tornado is most likely to occur around 5:00 P.M., but EF5 tornadoes most commonly occur in the middle of the night because it takes a long time to reach that intensity
False
Doppler radar is a useful tool for examining a tornadic supercell, but it can only view the storm parallel to the earth's surface. Scientists hope to develop the ability to scan the storm vertically in the next decade.
False
During vortex breakdown, the tornado contracts and an updraft dominates the center of the vortex
False
F0 tornadoes are the least common tornadoes.
False
From a statistical point of view, the most likely months for tornadoes in the United States are July and August because surface heating is greatest during these months
False
In the center of a tornado, the air is believed to be in hydrostatic balance
False
Landspouts typically develop out of supercell thunderstorms
False
Tornado Alley includes the states of Florida, Georgia, Alabama, and Mississippi.
False
How would you expect the frequency and geographical distribution of tornadoes to change seasonally?
Figure 19.18 shows the frequency change as a function of month.
Which two states experience the most tornadoes per 10,000 square miles? Which state experiences the greatest number of strong to violent tornadoes per 10,000 square miles?
Florida and Oklahoma experience the most tornadoes per 10,000 square miles? Oklahoma experiences the greatest number of strong to violent tornadoes.
How do suction vortices form in a tornado?
In the process of vortex breakdown, a downdraft extends downward to the surface in the center of the tornado. Shear between outward flowing air from the base of the downdraft and inward flowing air drawn into the updraft generates rotation, which is stretched to form suction vortices.
Do all tornadic thunderstorms produce hook echoes in the radar reflectivity field? Why or why not?
No. In supercells, sometimes the rear flank downdraft has no precipitation within it and does not produce a radar echo. Non-supercell tornadoes are not associated with hook echoes.
What is the characteristic signature of a tornadic thunderstorm in a radar reflectivity image?
The hook echo in a supercell. The hook will often have a high reflectivity core associated with debris when a tornado is present
What is the role of low-level shear in the formation of tornadic supercells?
The horizontal rotation associated with low level vertical wind shear is tilted into the vertical by a storm updraft, causing the storm to rotate.
What is a mesocyclone? What is a typical width of a mesocyclone?
The mesocyclone is a cyclonic circulation, typically several kilometers or less in diameter, within the updraft region of a supercell thunderstorm, normally coinciding with the region where tornadoes form
What is the difference between a funnel cloud and a tornado?
The rotating column associated with a funnel cloud is not in contact with the ground. The rotating column with a tornado is in contact with the ground.
In what type of thunderstorms do landspout tornadoes typically develop? How do they develop?
They develop in squall line thunderstorms. They are formed when horizontally sheared flow along the front or gust front breaks into vortices, which are then stretched by an updraft associated with convection over the front.
Why are the primary regions of tornado occurrence generally in productive agricultural areas?
Thunderstorms provide the water needed for agricultural production.
What process causes the initial rotation in a supercell thunderstorm?
Tilting into the vertical of the horizontal rotation created by vertical wind shear
. A highway overpass is not a safe place to seek shelter from an approaching tornado
True
A mesocyclone signature in the radial velocity data can be a precursor to tornado formation.
True
Based on recent measurement, the pressure in the center of a tornado can be as much as 100 mb lower than the air surrounding the tornado
True
Current evidence shows that of all supercells that have a clear mesocyclone signature on radar, less than 30 percent produce a tornado
True
Many of the worst tornadoes occur in Oklahoma where very sharp dry lines and cold fronts are a common occurrence in spring and early summer.
True
On the order of fifty people are killed in the U.S. each year by tornadoes.
True
Some states in Tornado Alley include: Oklahoma, Kansas, and Texas.
True
The process of tornado formation is called "tornadogenesis
True
The rotation of the mid-level mesocyclone in a supercell thunderstorm is a result of tilting of vertical wind shear by the storm's updraft.
True
Tornadoes classified as EF5 typically exhibit EF5 winds only briefly in their lifetime and only over a small area relative to the entire damage path of the tornado.
True
Tornadoes may form in supercell thunderstorms, squall line thunderstorms and hurricanes.
True
Tornadoes typically move from the southwest to the northeast.
True
Tornadoes vary in size but generally are on the order of 150 feet to a half mile in diameter.
True
Tornadogenesis occurs in a three step process: 1) development of rotation in the mid-levels (the mid-level mesocylone), 2) development of rotation in the wall cloud (the low-level mesocyclone), and 3) development of rotation at the ground
True
Within a supercell, the process of vortex stretching concentrates the rotation in a mesocyclone.
True
Worldwide, areas that commonly experience tornadoes are also major agricultural regions.
True
Where does a tornado form relative to the primary features of a supercell thunderstorm?
Typically forms on the southwest side of the storm under the rotating mesocyclone. Typically found extending downward from the wall cloud under the rain-free base of the updraft.
During vortex breakdown, what occurs in the center of the tornado vortex? (a) a downdraft develops (b) the air becomes supersaturated (c) the air moves into hydrostatic balance (d) (a), (b) and (c) are all correct.
a) a downdraft develops
Supercell rotation develops as a result of which two processes? (a) weaving and bobbing (b) twisting and turning (c) tilting and stretching (d) tossing and turning (e) rocking and rolling
c) tilting and stretching
Tornado Alley is located from Texas to Indiana. Why? (a) This region aligns approximately with the typical orientation of strong cold fronts or dry lines as they move across the central United States. (b) This region aligns with the typical orientation of the jet stream during supercell outbreaks. (c) This region has the highest number of mobile home parks per capita. (d) only (a) and (b) are correct. (e) (a), (b), and (c) are all correct.
d) only (a) and (b) are correct.
List and describe the different stages of the life cycle of a long-lived tornado.
dust swirl stage: Tornado begins as rotation makes contact with the ground organizing stage: The funnel cloud descends to the ground and increases in intensity mature stage : The intensity of the vortex peaks - tornado is at its largest size and is often nearly vertically erect shrinking stage: The vortex tilts over and begins to take on a rope-like appearance. decay stage: Tornado stretches into rope-like formation and dissipates
In what state do the largest number of violent tornadoes occur? (a) Texas (b) Florida (c) Illinois (d) Nebraska (e) Oklahoma
e) Oklahoma
The majority of tornadoes move in which direction? (a) west to east (b) south to north (c) southeast to northwest (d) northeast to southwest (e) southwest to northeast
e) southwest to northeast
What environmental condition is required for supercell thunderstorms to acquire rotation?
vertical wind shear