UBC  ATSC 201 - Meteorology of Storms

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Week 5  29 Sep - 5 Oct 2025
Monday (D1) Finish Homework from previous week.
Be sure your name, student number, and HW# are at top of every page.
Deadline:  Turn in your HW electronically by the start of class, 2 pm Pacific Time, Monday.
Morning
Midday
2 PM Class:
  1. Turn in HW.
  2. Discussion & interaction on topics from last week (bring your clicker).
  3. Keynote slides of tornado characteristics, and safety recommendations.
  4. Videos of tornadoes and mesocyclones:  Show YouTube videos Day 2-01 and Day 3 (all)
 Topic: Tornadoes
.
Learning Goals
At the end of this section, you should be able to:
  1. Visually recognize and identify tornadoes and associated wall clouds.
  2. Visually determine the life-cycle stage of a tornado and anticipate its subsequent evolution.
  3. Classify the different types of tornadoes.
  4. Propose how to safely chase and photograph tornadoes.
  5. Classify tornado strength using the Enhanced-Fujita scale.

Evening Readings:
  • S. Ch15. p577 - 589.  Also section 15.4.9 .
Warm-up Questions:
Do quiz W05 D2 online on Canvas.
 Topic: Tornadoes & Helicity
    Textbook sections Ch15. p577 - 589.  Also section 15.4.9.
Learning Goals
At the end of this section, you should be able to:
  1. Distinguish between the rotational and translational velocities of a tornado, and explain the forces that drive these motions.
  2. Explain how thunderstorms get rotation, and describe the rotation is enhanced.
  3. Apply the concepts of helicity and storm-relative helicity to explain severe storm evolution.
  4. Determine helicity from a hodograph.
  5. Relate swirl ratio to the existence and characteristics of multiple-vortex tornadoes.
Tuesday (D2)
Morning
Midday
Evening
10 PM Deadline to finish warm-up Qs.
Wed. (D3) .
Morning
Midday
2 PM Class:
  1. Discussion & interaction on topics from readings (bring your clicker).
  2. Demo on using a hodograph to describe mesocyclone winds.

Evening Readings:
  • S.Ch14. Section 14.1.4.2
  • S.Ch15. Section 15.1.
Warm-up Questions:
Do quiz W05 D4 online on Canvas.
 Topic: Mesoscale Convective Systems (MCS), Heavy Rain, Hail
    Textbook sections 14.1.4.2 and 15.1.
Learning Goals
At the end of this section, you should be able to:
  1. Compare and contrast MCS storms with other types of thunderstorm types.
  2. Describe the main characteristics of each type of MCS.
  3. Explain how hailstones are formed.
  4. Recognize hail indicators in weather radar.
  5. Take action to be safe if a hailstorm approaches.
Thurs. (D4)
Morning
Midday
Evening
10 PM Deadline to finish warm-up Qs.
Friday (D5) .
Morning
Midday
2 PM Class:
  1. Discussion & interaction on topics from readings (bring your clicker).
  2. Videos of hail:  Day4-25 thru Day4-35.

Evening
End-of-Week Numerical Homework Exercises.  
(Due at start of next class.)

Homework 5:
S.Ch15 (do all on a spreadsheet):  A1g ,  A3g ,  A26g ,  A27g ,  A29g ,  A33g ,  A36g.

Pre-readings for next week on lightning and thunder: Ch 15 section 15.3 (but skip 15.3.1 and 15.3.6.1)

 Learning Goals
At the end of this section, you should be able to:
  1. Apply topics covered earlier this week to compute number answers & infer their significance.  
Saturday(D6)
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Sunday (D7)
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Notes: The textbook for this course is Stull, 2018: "Practical Meteorology: An Algebra-based Survey of Atmospheric Science", available for free online, at  https://www.eoas.ubc.ca/books/Practical_Meteorology/ .

The reading and homework assignments use the following abbreviations to indicates various parts of this textbook:

Legend:
Ch = chapter.
A = "Apply" exercises.
p = page number.
S = Stull, 2018:  "Practical Meteorology" book (online).
s = "Synthesize" exercises.
E = "Evaluate & Analyze" exercises.