What are the three "necessary ingredients" for the formation of any type of thunderstorm?
-Warm moist air
-Lifting mechanism "kicker"
How do the formation conditions, weather features, and lifetime of severe thunderstorms differ from ordinary (air mass) thunderstorms?
-Conditions- Ordinary thunderstorms converging uupwards, limted wind shear. Sever thunderstorms convection ,aloft of wind shear.
-Weather features- Ordinary. Same amount of updraft and downdraft. Sever. Stronger updraft, rides over downdraft.
-Lifetime- Ordinary. 30min or less. Sever. Hours.
In what region of the United States do dry-line thunderstorms most frequently form?
Texas, Oklahoma, Kansas.
Where does the highest frequency of ordinary thunderstorms occur in the United States. Why there?
Because, hot moist air promotes convection.
Describe how thunder is produced.
Steam of negatively charged electrons looking for a positive connection between the clouds and the ground.
Explain why the central part of the united states (tornado Alley) is more susceptible to tornadoes than any other region of the world.
Because of the mountain region, continental polar (cP) and maritime Tropical (mT) air colliding.
Describe the role of wind shear in the formation of super cell tornadic thunderstorms.
Surface wind and winds aloft create a spinning vortex tube that is being lifted by an updraft.
How has Doppler RADAR helped in the detection and warming of a tornadic event?
Doppler RADAR can detect the hook echo to give pre-warning that a tornado is being formed.
Tornado "season": Explain why there are more tornadoes in the spring and early summer months.
Because the surface is warm and humid, with cooler and drier air aloft, producing a conditionally unstable environment.
Know the difference between a Tornado watch and Tornado Warning, including who issues them.
Tornado watch- is that a tornado may form.
Tornado warning- is when a tornado is forming.
-National weather service.-
Know the three conditions of the National Weather Service's Definition of a Severe Thunderstorm.
Large Hail, High winds of 58+, one or more Tornadoes.
Define "derecho". Know how to recognize it on a RADAR screen. Cite one Local Occurrence.
Weather storm that is caused in an extensive area of very damaging straight line winds. Local Occurrence- 1998 NY state fair.
Know the term "entertainment" and its role in the formation of a thunderstorm's downdraft.
Mixing of environmental air into a pre-exciting air current or cloud that the environmental air becomes part of the current or cloud.
Chapter 10 additional Key Terms and concepts.
Enhanced Fujita Scale-
-a scale that describes tornado intensity by observing damage caused by the tornado.
-a boundary that separates a cold downdraft of a thunderstorm from warm, humid surface air. On the surface its passage resembles that of a cold front.
-a vertical column of cyclonically rotating air within a super cell thunderstorm.
-a strong localized downdraft less than 4 km wide that occurs beneath thunderstorms. A strong downburst greater than 4 km across is called macroburst.
-a line of thunderstorms that form along a cold front or out ahead of it.
-an area of rotating clouds that extrends beneath a super cell thunderstorm and from which a funnel cloud may appear. Also called a collar cloud and pedestal cloud.