San Francisco State University Name___________________________________
Department of Earth & Climate Sciences

ERTH 260:Laboratory 9
Joplin Tornado Day, May 22, 2011
Weather Pattern and Thunderstorm Potential Diagnosis
(150 points)

Lab Due (with Presentations) on Wednesday 18 April 2018. Organizational Work among the groups done on Friday 13 April. Background for Questions 3 and 4 will be done on 11 and 13 April.

This exercise has you analyzing and examining weather charts to infer the conditions that occurred prior or during the time of the Joplin MO tornadic thunderstorm. Please put verbal answers on separate sheet of paper. Everyone is responsible for completing all exercises on their own, although you may work together.

You already have the 500 mb and 700 mb charts from Lab Exercise 6.

Presentations: Organizer for a particular chart or group of charts in bold face. For each question, organizer will ensure each person has something to say in the presentation.

  1. Surface Chart (18 points)
    1. Place values on the isobars (this is a so-called subsynoptic plot; isobars are conventionally drawn at 2 mb intervals on such a chart) (2 points)
    2. Label Lows (there are no Highs)(use proper colors). (2 points)
    3. Draw Streamlines (color coded; blue=cold; red=warm moist; brown=warm dry) (2 pts each for 6 points total)
    4. Analyze the boundaries labeled A, B, C and D (use proper symbols and colors). (2 points each, for 8 points total)
  2. 500 mb and 700 mb Charts (12 points)
    1. Analyze troughs and ridges, highs and lows. (5 points each chart)
    2. Briefly comment on the wind directions and speeds over the Joplin area.(2 pts)
  3. Soundings for Sites north and south of Springfield Missouri: Convective potential in the morning. (60 pts total)
    1. Little Rock AR 12 UTC 22 May 2011
      1. Specify how this sounding resembles the prototype "Loaded Gun Sounding"; (complete sentences, please) (5 pts)
      2. Analyze for morning convective potential...determine LCL, LFC, EL, show CAPE and CIN areas. (15 points); (Indicate these things right on the sounding, and make sure you show the parcel ascent curve)
      3. Characterize the stability characteristics of this morning sounding. (Complete paragraph please) (10 pts)
    2. Topeka KS, 12 UTC 22 May 2011
      1. Specify how this sounding resembles the prototype "Loaded Gun Sounding";(complete sentences, please) (5 pts)
      2. Analyze for morning convective potential...determine LCL, LFC, EL, show CAPE and CIN areas. (15 points)(Indicate these things right on the sounding, and make sure you show the parcel ascent curve)
      3. Characterize the stability characteristics of this morning sounding.(Complete paragraph please)(10 pts)
  4. Surface-based CAPE and CIN Analysis. Notice the locations A, B and C. (10 points)
    1. If thunderstorms develop, at which of the three locations would thunderstorm updrafts at the Equilibrium Level be the strongest and why? (3 pts)
    2. At which of the three locations is there the least chance of thunderstorms and why?(3 pts)
    3. At which of the three locations is thunderstorm development most likely at the time of the chart and why? (4 pts)
  5. Presentations: Question 1 (Rami and Allen) ; 2(Cynthia);Question 3a (Kellen Tanay, and Emma) Question 3b (Linda, Nicholas, Yan Tung); Question 4 (Wyndham and Nicolas). (50 pts)