LAB 8 Cyclonic Storms Answer Sheet

Cyclonic Storms Part A. Air Masses 1. What would the general temperature and humidity conditions be for the following types of air masses? a. cP: This air mass corresponds to the cold polar air masses that originate over polar continental areas. These air masses are extremely cold and dry. Hence, the temperatures are extremely low and humidity is very low. b. mP: This air mass originates over the polar maritime areas in the Northeast and Northwest portions of the Oceans i.e., the Arctic and the Pacific Ocean respectively. These air masses have a low temperature but high humidity since these air masses come from over-water bodies. c. mT: These air masses originate over tropical water bodies such as the Gulf of Mexico. These air masses are warm and humid. Since they are formed mostly in tropical areas, these air masses are warm and their location over water bodies renders them humid. 2. Figure 7.1 below, shows the source region and direction of most of the air masses that influence the weather conditions of North America. Label each of the air masses (cP; cT; mP; or mT). Figure 7.1: Map of North America and Significant Air Masses. 1 1 Figure by Scott Crosier is licensed under CC BY-NC-SA 4.0 1 | Lab 7: Cyclones

3. What two major air masses would influence the weather of California? mT and mP 4. Which air masses would have the greatest impact on weather along the central part of the United States? cT, cP and mP 5. In one sentence, describe the location of Tornado Alley. The Tornado alley is located between the Rocky mountains and Appalachian Mountains.Mainly towards the east of the Rocky mountains. 6. What influence do you think the colliding air masses have on the high probability of tornadoes occurring in Tornado Alley? Explain your response in one to two sentences. The collision of air masses creates an ideal environment for tornadoes to form within thunderstorms. The warm air rises through the colder air, causing an updraft that starts to rotate. 7. Use Your Critical Thinking Skills: Why do you think California has so few tornadoes? Explain your response in one to two sentences. Tornadoes occur very few in California because of its geographical set up , the mountains surrounding the state of California that traps heat in that region and does not allow formation of cold air in that region.It is typically a dry state. Part B. Fronts and Frontal Lifting 8. Based on the diagram of air masses in Figure 7.1, where would you most likely see these fronts developing (North, South)? The warm front would be in the South. Cold fronts would be in the North. Stationary fronts would most likely be in the Mid-South. 9. Along a ____Cold_________ front you will find the warm, humid air rapidly being forced up, leading to more severe storms. 10. Along a _____Warm________ front, the warm, humid air more gradually slides up and over the cooler, more dense air mass. 2 | Lab 7: Cyclones

15. Based on the temperature of the ocean currents off the Pacific and Atlantic coasts, why do we find much greater tropical storm development in the Atlantic Ocean influencing the United States? Why don’t we see many in California? Explain your responses in two to three sentences. The Pacific coast has cool water and the Atlantic coast has warmer water. The warm water in the Atlantic helps maintain tropical storm development such as a hurricane. We do not see many of these in California because the water temperature is much cooler and does not provide enough thermal energy to sustain a hurricane's strength. 16. Complete the table by determining the storm category based on the wind speed. You should reference Table 7.1 above. Table 7.2: Hurricane Katrina Data 2 Date Time Approx. Degrees North Approx. Degrees East Pressure (mb) Wind Speed (knots) Category Aug 23, 2005 1800 23 75 1008 30 Tropical Depression Aug 24, 2005 1800 25 77 1003 40 Tropical Storm Aug 25, 2005 1800 26 80 988 60 Tropical Storm Aug 26, 2005 1800 25 83 968 85 Hurricane Category 2 Aug 27, 2005 1800 25 85 948 100 Hurricane Category 3 Aug 28, 2005 1800 26 89 902 150 Hurricane Category 5 Aug 29, 2005 1800 31 90 948 80 Hurricane Category 1 Aug 30, 2005 1800 37 87 990 30 Tropical Depression Aug 31, 2005 600 40 83 996 25 Tropical Depression 2 Data sourced from NOAA National Centers for Environmental Information 4 | Lab 7: Cyclones

17. In the data table above, what relationship do you see between pressure and wind speed? High wind speeds are accompanied by reduced air pressure. The lower the pressure, the higher the wind speeds. 18. Based on the provided coordinates in Table 7.2, plot the daily location of Hurricane Katrina in the map (Figure 7.13) provided below. Using colored pencils, code each point according to the category of storm. Create a legend in the space below that shows the color used for each storm category. Tropical Depression : BLUE Hurricane Category 1 : PINK Hurricane Category 2 : GREEN Hurricane Category 3 : YELLOW Hurricane Category 5 : RED Tropical Storm : ORANGE 5 | Lab 7: Cyclones