Lab 7. Cyclones

Name: Nathan Thompson Date: 2/22/2024 Lab 7: Cyclones 1. What would the general temperature and humidity conditions be for the following types of air masses? a. cP: Cold and Dry b. mP: Cold and Humid c. mT: Warm and Humid 2. Refer to Figure 7.1, which shows the source region and direction of most of the air masses that influence the weather conditions of North America. a. Label each of the air masses (cP; cT; mP; or mT). Figure 7.1: Map of North America and Significant Air Masses. 1 b. What two major air masses influence the weather of California? mP and mT c. Which air masses have the greatest impact on weather along the central part of the United States? Continental Polar and Maritime Tropical 3. Based on the diagram of air masses in Figure 7.1, where would you most likely see these fronts developing in the United States? Mostly the Midwest to South and East of the US. 4. Compare Figures 7.5 and 7.6. a. Along a Cold front you will find the warm, humid air rapidly being forced up, leading to more severe storms. b. Along a Warm front, the warm, humid air more gradually slides up and over the cooler, more dense air mass, leading to mild storms. 1 Figure by Scott Crosier is licensed under CC BY-NC-SA 4.0 Answer Sheet page 1 | Lab 7: Cyclones

5. Refer to Figure 7.7. a. In one sentence, describe the location of Tornado Alley. Mid to East(ish) US where cP and mT air masses meet. b. Refer back to Figure 7.1 (shown earlier in the lab). 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 cP fronts are more likely to encounter the warm air from the mT and cT from middle of the America (e.g. Kansas, Oklahoma) , to the East (e.g. Ohio). This general area looks to be where most of these opposing fronts mix, creating cyclones. c. Use Your Critical Thinking Skills: Why do you think California has so few tornadoes? Explain your response in one to two sentences. The mP and mT airs are less drastic and are not directly pushing into eachother the same way the concentrated cP and the warm mT/cT are. In the area inland the air masses are directly opposing each other. 6. How would the air pressure differ between the north side of a stationary front versus the south side of the same front? Explain your response in one to two sentences. The North side of the stationary front would have higher pressure because the cold air is coming from that direction, cold air has more pressure. The south side on the other hand will have less pressure as it is less dense, even if they are in a stationary front. 7. Storms typically include cloud formation and precipitation. Which air mass contains the greater amount of humidity? The greatest amount of humidity comes from the Maritime Tropical. 8. In the northern hemisphere, would the Coriolis effect cause surface-level winds to move into a low pressure system in a clockwise or counterclockwise direction? Counterclockwise. 9. Cold fronts typically move faster than warm fronts. If the cold front rotates faster around the central low pressure, what would you expect to happen to the two different fronts? Explain your response in one to two sentences. The cold front continues to rotate faster while the warm air must catch up. The cold air has the most pressure but the warm air keeps the pressure lowered until it dissipates. 10. Review the five stages of midlatitude cyclones. a. List the initial conditions needed to cause a midlatitude cyclone to form: A stationary front. b. List the ending conditions that cause a midlatitude cyclone to dissipate: An occluded front that leads to dissipation. Answer Sheet page 2 | Lab 7: Cyclones

Figure 7.14: Progression of Hurricane Katrina, August 23–31, 2005. 4 15. Compare the direction of travel of the storm between the 23rd to the 26th with the projection of the storm between the 27th to 30th. List the differences that you notice. The 23 rd to the 26 th the storm was traveling west past the peninsula, the 27 th to the 30 th the storm started traveling north inland. 16. Did the storm travel the same speed each day? What trends in storm speed do you see? Explain your response in two to three sentences. The storm gradually increases speed as it reaches the peninsula. Then the storm entered the gulf and then exponentially gained speed until it dissipated inland. 17. Complete the far-right column of Table 7.3 by determining the storm category based on the wind speed. You should refer to the Saffir-Simpson Hurricane Severity Scale (Table 7.1, shown above) to complete the Category column. Table 7.3: Hurricane Harvey Data 5 Date Time Approx. Degrees North Approx. Degrees West Pressure (mb) Wind Speed (knots) Category Aug 16, 2017 1200 14 47 1010 25 Tropical Depression Aug 17, 2017 1200 13 53 1008 30 Tropical Depression 4 Figure by Scott Crosier is licensed under CC BY-NC-SA 4.0 5 Data sourced from NOAA National Centers for Environmental Information Answer Sheet page 4 | Lab 7: Cyclones

Aug 18, 2017 1200 13 60 1004 40 Tropical Storm Aug 19, 2017 1200 14 68 1006 30 Tropical Depression Aug 20, 2017 1200 14 75 1006 30 Tropical Depression Aug 21, 2017 1200 16 83 1008 25 Tropical Depression Aug 22, 2017 1200 19 89 1010 25 Tropical Depression Aug 23, 2017 1200 21 92 1006 30 Tropical Depression Aug 24, 2017 1200 24 93 986 60 Tropical Storm Aug 25, 2017 1200 26 96 949 95 Category 2 Aug 26, 2017 1200 29 97 978 65 Category 1 Aug 27, 2017 1200 29 97 998 35 Tropical Storm Aug 28, 2017 1200 29 96 997 40 Tropical Storm Aug 29, 2017 1200 28 96 995 40 Tropical Storm Aug 30, 2017 1200 30 93 992 40 Tropical Storm Aug 31, 2017 1200 32 92 1001 20 Tropical Depression Sep 1, 2017 1200 36 87 1002 25 Tropical Depression Sep 2, 2017 1200 38 85 1013 15 Tropical Depression 18. Based on the provided coordinates in Table 7.3, plot the daily location of Hurricane Harvey on the map provided below (Figure 7.15). Using colored pencils, code each point according to the category of storm. Use the same colors as you did for question 14 (Figure 7.14) and add a legend to the map. With a black line, connect each of the points to mark the storm's trajectory. Answer Sheet page 5 | Lab 7: Cyclones