Solutions to Comprehensive Final Examination Given on Thursday, 13 December 2001

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1 Name & Signature Dr. Droegemeier Student ID Meteorology 1004 Introduction to Meteorology Fall, 2001 Solutions to Comprehensive Final Examination Given on Thursday, 13 December 2001 BEFORE YOU BEGIN!! Please be sure to read each question CAREFULLY and, if time permits, check your answers. Answer all questions on the pages provided - do not use additional sheets. Be sure to submit your computer form as well as the exam before leaving the room. This exam is worth 200 points and must be completed by 10 am. Part I: Multiple Choice (2 points each) - Indicate the correct answer on the computer form using a #2 pencil. 1. If a thunderstorm is moving toward the east at 20 m/s and the environmental wind is from the west at 50 m/s, the storm-relative wind will be a. 30 m/s from the east b. 30 m/s from the west c. 70 m/s from the east d. 70 m/s from the west e. None of the above 2. Which of the following weather events typically is NOT associated with squall lines? a. Trailing stratiform precipitation b. Hail c. Strong, gusty winds d. Heavy precipitation e. Strong tornadoes 3. The mesocyclone acquires rotation about a vertical axis via a. Stretching of Earth's vorticity b. Tilting of horizontal vorticity associated with environmental vertical wind shear c. Curvature vorticity d. Baroclinic gradients e. Both c and d

2 4. The likelihood of supercell storm development will be greatest when the Bulk Richardson number is a b. 500 c. 100 d. 50 e Supercell updrafts will tend to rotate cyclonically if the low-level storm-relative wind vector and horizontal vorticity vector tend to be a. Antiparallel b. Perpendicular c. Parallel d. The same magnitude e. None of the above 6. Which of the following is responsible for producing most of the warm-season precipitation in the central US? a. Mesoscale convective complexes b. Single-cell (air mass) storms c. Supercell storms d. Squall lines e. Bow echoes 7. The bounded weak echo region within a supercell storm is an indication on radar of a. An intense downdraft b. Large hail c. Intense lightning d. An intense updraft e. both b and d 8. According to a study by Bluestein, which of the following modes of squall line development is LEAST common? a. Broken line b. Back building c. Broken areal d. Embedded areal e. Assembly line 9. The heaviest precipitation within a supercell storm is found in the a. Forward flank downdraft b. Gust front c. Overshooting top d. Rear flank downdraft e. Flanking line

3 10. Strong mesocyclones likely would be forecast if the storm-relative environmental helicity is in the range (units are m 2 /s 2 ) a. 1-5 b c d e. none of the above 11. A hook echo is a visual indication on radar of a. The wall cloud b. The mesocyclone c. The rear-flank downdraft d. The gust front e. Both a and d 12. In a classic squall line, a large region of stratiform precipitation typically is found a. Behind the intense convective cells b. Ahead of the intense convective cells c. Well ahead of the warm front d. At the leading edge of the gust front e. None of the above 13. Strong vertical shear of the horizontal wind, in the presence of weak CAPE, will tend to a. Result in supercells b. Rip developing clouds apart c. Produce light, widespread precipitation d. Produce single cell (air mass) storms e. Both b and d 14. If the environmental winds are from the north and increase in speed with height while not changing direction, then the horizontal vorticity vector will point toward the a. North b. South c. West d. East 15. If an object is able to absorb a great deal of energy without much of an increase in temperature, it is said to have a a. Small heat capacity b. Small latent heating c. Small heating of fusion d. Large heat capacity e. Large heat of vaporization

4 16. For this problem, reference the table shown to the right. If the temperature of a sample of air is equal to 70 F and the relative humidity is 85%, then the dew point is approximately equal to a. 45% b. 55F c. 60F d. 65F e. 70F. 17. The most abundant constituent of air is a. Oxygen b. Ozone c. Nitrogen d. Water vapor e. Argon 18. The region of the atmosphere immediately above the stratopause is known as the a. Troposphere b. Stratosphere c. Mesosphere d. Thermosphere e. Ionosphere 19. If the temperature of the sun increased by a factor of 3, the amount of energy output would increase by a factor of a. 3 b. 6 c. 9 d. 27 e If a rising parcel condenses but does not lose any of its precipitation, the process is said to be a. Saturated/moist adiabatic b. Dry adiabatic c. Pseudoadiabatic d. Diabatic e. None of the above 21. The heaviest precipitation associated with a mature extra-tropical cyclone typically occurs a. Well behind the cold front b. Above the surface low c. Well behind the warm front d. In the warm sector e. None of the above

5 22. Ahead (to the east) of the axis of an upper-level short wave trough, one typically finds a. Convergence b. Divergence c. Rising motion d. Sinking motion e. both b and c 23. Which of the following is NOT a factor in determining local climate? a. Vegetation b. Topography c. Altitude d. Latitude e. Water quality 24. How does the ocean tend to affect the yearly range of temperature for coastal cities? a. Increases the range b. Decreases the range c. Does not affect the range significantly d. Affects only summer temperatures e. Affects only winter temperatures 25. Which of the following forces is NOT involved in cyclostrophic wind balance? a. Centrifugal b. Gravitational c. Pressure gradient d. Coriolis e. both b and d Part II: True/False (2 points each) - Indicate the correct answer on the computer form using a #2 pencil. 26. A temperature inversion marks a region of greatly increased stability 27. The adjective "specific" in meteorology (e.g., specific heat) means "per unit volume". 28. Microbursts tend to last longer than their parent thunderstorm

6 29. The albedo of green grass is less than the albedo of fresh snow 30. Except at saturation, the dew point temperature is always greater than the wet bulb and less than the air temperature 31. In a well-mixed boundary layer, the temperature decreases with height at the dry adiabatic lapse rate 32. Divergence aloft generally indicates the presence of rising motion below 33. A barotropic weather system is one that is in its early developmental stages 34. A wind that veers with height from the ground to 2 km altitude is considered advantageous for the development of thunderstorms 35. The most intense tornadoes typically form within LP supercell storms Part III: Definitions (5 points each) - Provide a short definition for each term in the space provided. 1. Advection The transport of a quantity by the wind. 2. Thickness The difference in height between two constant pressure surfaces. It is proportional to the mean temperature of the layer.

Short wave trough A small wave that moves through the long- (Rossby) wave pattern in the middle and upper troposphere.

7 3. Geostrophic wind An idealized, unaccelerated (straight-line flow at constant speed) wind represented by an exact balance between the Coriolis and pressure gradient forces. 4. Mesocyclone The rotating updraft of a supercell thunderstorm. 5. Short wave trough A small wave that moves through the long- (Rossby) wave pattern in the middle and upper troposphere. Part IV: Short Answer (points as shown) - Provide a concise answer to each of the questions listed below. 1. (20 points) On the diagram below, indicate the supercell storm features in the spaces provided.

8 2. (30 points) For this question, refer to the color thermodynamic diagram distributed with the exam. a. Plot the following sounding. Pressure (millibars) Temperature (deg C) Dew Point (deg C) b. List the altitudes (in mb) of all inversions Approximately 850 mb and 500 mb c. Find the altitude (in mb) of the lifted condensation level (LCL) (indicate your work on the diagram) Approximately 860 mb d. Find the altitude (in mb) of the convective condensation level (CCL) (indicate your work on the diagram) Approximately 800 mb e. Shade the region indicating the CAPE (indicate your work on the diagram) f. Cross-hatch the region indicating the CIN (indicate your work on the diagram)

9 3. (30 points) Provide all of the information requested for both hodographs shown below. Assume a CAPE of 3000 J/kg, and NOTE THE WIND SPEED SCALE OF THE HODOGRAPH. a. Draw the vertical shear and horizontal vorticity vectors at the altitudes indicated. b. What type of storm will form if the updraft moves as indicated by the storm motion vectors A, B, C, D, and E? Place the type of storm next to the letter.

10 4. (15 points) Illustrate and briefly explain the conditions of low-level, environmental vertical wind shear that are necessary for obtaining long-lived squall lines. Start with an isolated cloud growing in a non-sheared environment.

11 5. (10 points) a. For large-scale, horizontal flow circulating clockwise around a high pressure center, indicate the balance of forces. The forces involved are the pressure gradient force (PGF), centrifugal force (CENT), and Coriolis force (COR), i.e., gradient wind balance. V CENT PGF COR H c. Repeat part a, but this time for a small-scale vortex, e.g., a tornado. The forces involved are the pressure gradient force (PGF) and centrifugal force (CENT), i.e., cyclostrophic wind balance. Clearly the forces cannot balance, and thus one cannot have a high in the center of such a vortex. As shown in class (recall the washing machine example), one always finds low pressure at the center of a cyclostrophic vortex. V CENT PGF H

Examination #3 Wednesday, 28 November 2001

Name & Signature Dr. Droegemeier Student ID Meteorology 1004 Introduction to Meteorology Fall, 2001 Examination #3 Wednesday, 28 November 2001 BEFORE YOU BEGIN!! Please be sure to read each question CAREFULLY