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 5

• Supertyphoon Mangkhut hits Hong Kong, Shenzhen & Macau on 15 September 2018.  Footage compiled by Miscelánea Noticias (MN).  https://www.youtube.com/watch?v=iHiKFK7BRPs  (2:37. Not testable.)
  

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

Hurricane Description — Anatomy of a Hurricane

1. Hurricanes are made of thunderstorms, and have all the thunderstorm hazards plus ocean-related hazards. Hurricanes = typhoons = tropical cyclones.  (1:17.  Lecture video snippet d5s01.)

2. Hurricanes are relatively thin (15 km in vertical) but have large diameter (300 km). Components include a relatively clear and calm eye with very low pressure, a violent circle of thunderstorms called the eye wall, and spiral bands of thunderstorms.  (2:51.  Lecture video snippet d5s02.)
   
   
3. YouTube video inside the clear sunny eye of category-5 Hurricane Michael, photographed by "StormChasingVideo.com" on 10 Oct 2018.  From their vantage point on the ground in Florida, they see the blue sky in the eye just before the backside of the eyewall hits them with more heavy rain and strong winds. (0:34 https://www.youtube.com/watch?v=JWkgFz3e__w )

Observations by Satellite and Radar

4. Observations of hurricanes by hurricane hunter aircraft, by weather satellite, and by weather radar.  These show hurricane Katrina in Aug 2005.  Can you identify the eye, eye wall, and spiral bands in these images?  (2:13.  Lecture video snippet d5s03.)

• Check your understanding.  (d5c1) 
  

A Disaster Scale for Hurricanes

5. The "Saffir-Simpson Hurricane Wind Scale". (2:14.  Lecture video snippet d5s04.)  Also, here is a link to the slide shown in the video snippet.
   

Hurricanes Create their own Fuel Supply

1. Compare the warm humid air "fuel tanks" for simple thunderstorm cells, supercell thunderstorms, and hurricanes.  See how hurricane winds create gigantic waves with lots of sea spray, enabling hurricanes to utilize energy stored in the warm oceans.  (5:48. Lecture video snippet d5s05.)

• Check your understanding.  (d5c2)
  

2. Hurricane season in the Atlantic peaks in September.  (1:20. Lecture video snippet d5s06.)

Hurricane Formation and Movement

3. The earth's rotation creates the Coriolis effect, which enables hurricanes over warm ocean locations except at the equator. (2:47. Lecture video snippet d5s07.)
   

4. Hurricanes die if they move over cold water, or over land. Can you explain why?  (2:34. Lecture video snippet d5s08.)

• Check your understanding.  (d5c3)
  

5. Larger-scale weather patterns control where hurricanes move, but can also kill hurricanes.  (4:03.  Lecture video snippet d5s09.)

• Check your understanding.  (d5c4)
  

Warm-core Hurricanes - The key to long life

6. The warm core (center part) of hurricanes creates relatively High pressure at the top of the storm, which drives the exhaust system needed to keep pressure Low at the bottom of the eye.(1:52. Lecture video snippet d5s10.)

• Check your understanding.  (d5c5)
  

Storm Surge

1. Hurricane risks relative to other risks.  (3:30. Lecture Video snippet d5s11.)  Also, here is a link to the 2022 risk graphics from the World Economic Forum Global Risks Report.
   

2. YouTube video of a storm surge at the Philippines, cause by Super Typhoon Haiyan (also known as typhoon Yolanda), photographed by Nickson Gensis in 2013. https://www.youtube.com/watch?v=rS0gv4Xbw7w  (1:08.)

3. Drowning is one of the main causes of hurricane-related deaths DURING the hurricane.  (0:56. Lecture Video snippet d5s12.)

4. YouTube video: Health dangers AFTER hurricane flooding is another significant hazard, as nicely summarized by Fox News in 2017 after Hurricane Harvey. https://www.youtube.com/watch?v=nc3ICtxH3qU (2:03)

Hurricane Prediction and Safety in Canada

5. Computer predictions of hurricane track and intensity are imperfect, so hurricane warnings are presented as probabilities. 
   Although hurricanes are infrequent in Atlantic Canada, forecasts are made by the Canadian Hurricane Centre, a branch of Environment and Climate Change Canada (ECCC).   (2:49.  Lecture video snippet d5s13.).

6. Update to the graphics of the previous lecture snippet: Hurricane Larry in 2021 was another category 1 hurricane when it made landfall on Newfoundland.    Other former hurricanes (tropical hurricanes that later transitioned to non-tropical storms) can still cause heavy rain and strong winds, such as former Hurricane Dorian that hit Nova Scotia in 2019.  

• Check your understanding.  (d5c6)  

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

2. A reminder of the topics we covered during the Storms module is in the "roadmap" table at the top of this web page.
   

3. My farewell to all of you. (0:20)  Lecture video snippet d5s14.)

Irish Blessing:
May the wind be always at your back,
May the sun shine warm upon your face, and
May the rains fall soft upon your fields.

Cheers, Prof. Roland Stull. 

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