Overview
Tornadoes 1. _____________________________ are violent windstorms that take the form of a rotating column of air called a vortex that extends downward from a cumulonimbus cloud. These violently spinning winds can reach speeds of 572 km/h. Typical tornado speeds across the surface range from _________ to ________ km/h.
2. Tornadoes are nature's most ___________________ storms and most significant natural hazard. 3. The United States has over __________ tornadoes per year, an unusually high number relative to the rest of the world. The country second to the United States in tornadoes is __________________________.
4. On the above below of North America label: 1) both the Rocky and Appalachian Mountains; 2) the areas of cold, dry air from Canada Air; and 3) Tropical Air from Gulf of Mexico.
5. Look at the shape of the two mountain ranges in conjunction with both the west and east coast. Describe the shape of North America and the two mountain ranges: ________________________________________________________________________________
6. The relationship between the mountain ranges and air masses indicates the _____________________________ region of North America will be cold and dry in the winter and hot and humid in the summer.
7. The storms that lead to tornadoes are created through the ______________________ of warm, moist air from the Gulf of Mexico with cold air moving south from ___________________________. Because there are no major east-west ranges to keep the air masses apart they collide.
8. ____________________________ is the region of the central United States that is most noted for frequent tornado outbreaks.
9. A series of tornadoes, called ____________________________, formed by a group of storms has killed as many as several hundred people and covered as many as thirteen states.
Using the figures to the right answer the following questions:
10. List the two states with the highest probability of tornadoes: __________________________________ __________________________________
11. What is the probability of a significant tornado per day per year in these two states (%): ___________ %
12. List the states located within Tornado Alley:
13. List the air masses that meet in Tornado Alley:
14. Tornadoes generally form where there is a shear in wind direction; surface wind ______________________ in an area where warm, humid air _________________________ is over advancing cold air. This shear can create a roll of horizontal wind currents in a thunderstorm as warm, moist air rises over advancing cold air.
15. The above figure illustrates the formation of a tornado. On the Figure label the following: 1) Southeasterly surface winds 2) Rotational counterclockwise wind 3) Updraft 4) Strong westerly wind flow aloft.
16. The peak tornado season is __________________________ to ______________________ in most of the southeast, moving to ________________________ farther north.
17. Tornadoes generally form towards the traveling _______________ of severe thunderstorm. This catches the people off-guard. People feel the worst of the __________________ is over once the heavy rain and hail have passed and skies begin to clear and are unprepared when the ____________________ touches down.
18. A tornado can form within minutes and last for __________ minutes to over an hour. Tornadoes rarely stay on the ground for more than 30 minutes, leaving a path less than ___________ km wide and up to __________ km long.
19. NOAA's Storm and Prediction Center in ________________ , Oklahoma, uses Doppler radar, wind profilers and surface observation systems to predict and identify tornadoes.___________________________
Match the descriptions of tornado related terms with the correct terms:
20. A scale for ranking how powerful a tornado is. Based on their internal wind speeds and the damage produced. _________
21. An alert that a tornado has been spotted in an area. _________
22. National Oceanic and Atmospheric Administration - a science agency that focuses on the conditions of the oceans and the atmosphere _________
23. A new generation of weather radar capable of detecting precipitation motion directly and is a useful tool for detecting tornadoes. _________
24. An alert that conditions in an area may be favorable to the development of tornados. _________
25. A curved, hook-shape pattern on weather radar maps that is indicative of a supercell thunderstorm and potential tornado. _________
26. A particularly strong rotating thunderstorm that can spin off dangerous _________ A. Hook Echo B. Supercell C. Enhanced Fujita Intensity Scale D. Tornado Warning E. Tornado Watch F. NOAA G. Doppler Radar
Hurricanes
27. Depending on the context, the word ______________________ may refer to a tornado, a hurricane, or a large-scale atmospheric system in the mid-latitudes. Though on different scales, all have in common a rotational pattern of winds.
28. A ____________________________ is a large tropical cyclone consisting of a low-pressure center surrounded by strong rotating winds. Generated in the North Atlantic and eastern Pacific.
29. Cyclonic storms, such as hurricanes, are characterized as a large area of _____________ (high/low) atmospheric pressure and strong winds rotating _______________ (inward/ outward) around the center of the storm.
30. When a large tropical cyclone occurs in the North Atlantic and eastern Pacific, it is called a _______________________ a term derived from a Caribbean native Indian word meaning Big _______________________.
31. The same type of storm is called a ____________________ in the western Pacific, Japan and Southeastern Asia.
32. In the Indian Ocean these storms are simply called ___________________________.
33. Surface temperature of the ocean must be at least ________ °F ( ______ °C) storm to form.
34. Hurricanes originate between_______ °and ______ °north or south of the equator. In these tropical latitudes the temperatures are high and the air- _________________ gradients are weak.
35. Tropical cyclones or hurricanes get their ____________(heat) and _________________ from the rising air of a low-pressure cell over the tropical ocean.
36. Air rises by localized heating and through condensation form convective “_________________" with frequent thunderstorms.
37. Warm, moist air over the ocean ___________________ and spreads out at the top of the chimney. The rising air expands, __________________ and releases latent heat. The air rises ______________ as the storm strengthens.
38. Rise of ________________ air near the eye pulls more moist air into the eye from low elevation at the periphery of the storm. ___________________ forces initiates rotation in the rising air, the highest winds and lowest air pressure traveling inward to the ________ of the storm.
39. The atmospheric pressure in the eye of the hurricane drops from normal atmospheric pressure of _________ millibars to __________ millibars.
40. In the eye of the hurricane the sake may be __________________ (cloudy/cloud free).
41. On the diagram below label the following: 1) Warm Ocean; 2) Area of Low Pressure; 3) Eye of Hurricane; 4) Eye Wall; 5) Areas of Rain/Rain Band; 6) Top of Chimneys
42. The __________________________________ Hurricane Wind Scale divides hurricanes into five categories based on average wind speed, with Category 1 storms being the weakest and Category 5 the strongest.
43. Hurricanes striking the gulf coast and east coast of North America originate in waters in near-equatorial latitudes off the west coast of _____________________.
44. Most hurricanes develop in the months of ________________ and _______________, because it takes all summer to warm the ocean.
45. Hurricanes in the North Atlantic are blown by the _____________ winds towards North America. They curve to the right because of the _______________ Effect and travel northward, often make landfall or pass close to shore. Eventually, hurricanes break-up and pushed out to sea by the _____________________.
46. When a hurricane moves onto land or onto a cold ocean, it rapidly loses its strength. This decline in storm intensity results from the lack of a source of _____________ air.
47. Most damage and fatalities associated with hurricanes are due to ______________________.
48. Hurricanes have ______________ wind speeds than tornados, but inflict more damage: Hurricanes are bigger, slower moving storms, effecting a ___________________ area than tornados. Tornadoes are "just wind", while hurricanes include flooding along the coast. Hurricanes also move more slowly and last longer than tornadoes.