Overview: There are 5 lectures on Storms. 
The "roadmap" table below outlines what we cover each day.

Learning Goals (LG) are listed at the end of this web page.

Storms Day 3

• This tornado in Manitoba was photographed on 26 Jun 2007 by Chris Hughes while driving to Alberta. Enjoy this optional short video "teaser" before class starts.  https://www.youtube.com/watch?v=xCI1u05KD_s  (2:41.  Not testable.)

• As another optional "teaser" before class starts, Pecos Hank, shows the incredible number of tornadoes he chased in 2016. https://www.youtube.com/watch?v=NZmtglWX0N4 (16:04.  Not testable.)

• Here is a link to a pdf copy of the slides that I present in the video snippets today.  Some students use these pdfs for note taking and studying.
  

1. Recognizing Tornadoes

1. Types and appearance of tornadoes.  (1:36. Lecture Video snippets:  Part a    d3s01a  and  Part b  d3s01b. )

2. YouTube video showing storm chaser Reed Timmer much too close to a tornado. https://www.youtube.com/watch?v=bjb7QtMEBUg (start at 2:30; namely, watch the last half of this AccuWeather video.)
   

3. Relative to a supercell thunderstorm, where is the best place to view a tornado?   (2:17. Lecture Video snippet d3s02.)
   

   • Check your understanding.  (d3c1)
     

2. Recognizing Mesocyclone Rotation

1. Clues of mesocyclone rotation, such as cloud striations.  (1:47. Lecture video snippet d3s03.)
   

2. • You can see the rotation of this supercell thunderstorm near Climax, Kansas, only because this YouTube video by Stephen Locke is sped-up (i.e., is time-lapse).  But if it wasn't sped-up, what clues could you use (looking at the clouds by eye) to infer that the thunderstorm is rotating as a mesocyclone? https://www.youtube.com/watch?v=Y4EK2r9JJ1k  (1:30; when played at 2x speed.)
   • Here is another excellent video showing cloud striations, recorded by Freddy McKinney in Nebraska in 2020  https://www.youtube.com/watch?v=zzBylV2QkuI (1:20; when played at 2x speed). 

3. Another clue of supercell (mesocyclone) rotation is a wall cloud. (0:56. Lecture video snippet d3s04.

4. YouTube video of a wall cloud near Amber, Okahoma, photographed by James Burch. https://www.youtube.com/watch?v=KiAqIqDOszg  (0:50 when played at 2x speed .)
   

5. Doppler weather radar allow us to detect rotation inside thunderstorms. (1:39. Lecture video snippet d3s10.)
   

   • Check your understanding.  (d3c2)
     

3. Tornado Speeds and Disaster Scales

1. Tornado translation across the countryside, and intense rotational wind speeds that cause destruction.  (2:34. Lecture video snippet d3s05.)

2. A description of damage associated with the Enhance Fujita (EF) scale is on this slide.  https://www.weather.gov/hun/efscale_explanation .
   

3. The Enhanced Fujita scale for tornado intensity, as illustrated in this YouTube video by Pecos Hank.  https://www.youtube.com/watch?v=c-uFdoi6DEA  (5:38 )
   

   • Check your understanding.  (d3c3)
     

4. Tornado damage -- another perspective.  (0:56. Lecture video snippet d3s06.)
   

5. YouTube video of a small car carried away by a tornado. https://www.youtube.com/watch?v=nddkiXuM4Ag  (watch the first 30 seconds)
   

6. YouTube video from a "dashcam" on a locomotive that is looking backwards over the remaining train cars, as the train is derailed by a tornado. https://www.youtube.com/watch?v=LYubpuIe3cw (0:43) .

4. Tornado Safety

1. Tornadoes are usually short lived, with narrow damage paths as shown in this image.  Longer lasting, larger size (see another image) tornadoes exist, but happen only rarely.      

2. Tips on how to survive a tornado.  (1:52. Lecture video snippet d3s07.)

5. Tornado Risk

1. Where is the greatest risk of frequent tornadoes?  (1:21. Lecture video snippet d3s08.)
   

2. Here is the world map showing locations of frequent tornadoes.  Here is an updated map showing newer understanding of the "tornado alley" region.  
   

3. Tornado Hits UBC !   Although tornadoes in the Vancouver area are extremely rare, an EF0 tornado hit UBC in late 2021.  The tornadic thunderstorm approached from over the water, and then moved across the Point Grey peninsula, causing tree damage in Pacific Spirit Park and at the UBC Golf Course.  The mesocyclone had both a hook echo and a Doppler-radar signature of a tornado.  
   

• Check your understanding.  (d3c4)
  

6. Tornado Outbreaks

1. Sometimes many tornadoes happen in a few days?  (2:13. Lecture video snippet d3s09.)
   

   • Check your understanding.  (d3c5)
     

7. Tornado Evolution

1. This slide shows the five stages of supercell tornado evolution.  Be cautious if you are watching or photographing a tornado, because a new tornado might be forming from the same supercell while you are distracted when focused on the old dissipating tornado.
   

8. Tornado Forecasting

1. Tornado watches and warnings, including ...
   ...Roland Stull's mis-adventures with weather -- Vignette 3.  (2:00. Lecture video snippet d3s11.)
   

   • Check your understanding.  (d3c6)
     

Summary

1. Summary slide listing the topics we covered in this lesson.  Next time we will learn how the heat released in thunderstorms causes the violent winds.  We will also look at hail hazards. 

2. The Learning Goals below are a good study aid for the topics we covered today.  Please review them now to reinforce your understanding. 
   

See you next time.  Cheers, Prof. Roland Stull. 

By the end of this lesson, you should be able to: