E. Aguado
Geography 303, Severe Weather
Fall 2014
Office Hrs: MWF 1100-1150
Office: Storm Hall 305C
Phone: 594-5930
email: aguado@mail.sdsu.edu
and by appointment
Course Description
Course Description: Physical processes, human responses, and mitigation strategies related to
atmospheric hazards, including blizzards, wind storms, severe thunderstorms, tornadoes, hurricanes, heat
waves, floods and drought.
Purpose and Scope of Course: This course explores severe weather phenomena across the world. It
first reviews the basic processes involved in all weather events and the observation/analytical resources
of the National Weather Service. We then apply the underlying physical principles of atmospheric
science to individual types of severe weather. Topics include, blizzards, ice storms, severe
thunderstorms, large hail, tornadoes, and derechos and other strong winds. The effect of climatic
forcings, such as El Niños and the Pacific Decadal Oscillation, on severe weather will also be explored.
Mitigation efforts and human responses will also be discussed, as well as impacts of global climatic
change on severe weather.
We will make extensive use of current weather information available on the World Wide Web, especially
as it applies to recent severe weather events.
Student Learning Outcomes: Students will integrate and link the processes involved in atmospheric
science with the resultant form and geographic distribution of severe weather phenomena. They will also
recognize the ways in which humans have tried to directly suppress the occurrence and intensity of
severe weather and how human-induced climatic change has affected the incidence of such events.
Students will also appreciate regional variations in human vulnerability to severe weather.
Text: The required textbook for this class is Severe and Hazardous Weather, 4th edition, by Rauber,
Walsh and Charlevoix, Kendall/Hunt, 2012. The corresponding chapters to each section are provided in
the course outline of this syllabus.
Grading Standards: Exams and the term paper will be assigned points from 0 to 100. The final course
grade will be based on the cumulative number of points accumulated and based on the overall
distribution of points. Rather than using a predetermined number of points for each grade (e.g., 70% =
C), the instructor will look for natural gaps in the point distribution and give grades based on the
clustering of scores. The tentative grade distribution will be given to the class after each exam is graded.
Term Paper: Student will write a 2000 – 2500 words) term paper worth 15% of the class grade. The
paper will have to analyze some major severe weather event and its impact on humans. The paper will
need to demonstrate a knowledge of the general type of weather event involved and the use of maps,
satellite imagery, and radar for explaining the event. For example, a paper discussing Hurricane Katrina
would not only describe the progression and evolution of the storm, but also how upper-level wind
patterns, sea surface temperatures, and interactions with large scale pressure patterns influenced the
storm. The paper will also need to provide an analysis of the overall impacts of the storm on the regions
directly impacted, as well as that of the United States as a whole. More detailed explanation of this
requirement will be provided later in the semester. This paper will be due at noon, Friday, December 19.
-2Exams: There will be two midterms and a non-comprehensive final exam (covering only the material not
tested on the two midterms). Each exam will be weighted equally and together account for 85% of the
course grade. Topics that are in the book but not discussed in lecture will not be on the exams unless
otherwise noted in class. The exams will consist of essays and short answer questions. The students’ final
grades will be determined by the total number of points received for the three exams and the term paper,
and graded on a curve. There will be no homework or extra credit assignments. Make-up exams will
only be allowed for special circumstances and should be arranged before the regular exam is given.
Exam Dates:
Exam #1
Friday, September 26 (subject to change with 2-week notice)
Exam #2
Friday, October 31 (subject to change with 2-week notice)
Final Exam: Friday, December 12, 1 p.m.
Class Resources: Nowadays everybody has access to real-time and historical weather data that goes
well beyond the information available to professional forecasters and other meteorologists in their offices
20 years ago. This class will frequently employ current maps, imagery and other information to examine
severe weather processes as they occur around the world. Your textbook has a web page with useful
resources. Though not required, it might be a good idea to see the online test questions, animations and
other resources.
Classroom Etiquette (Important!):
Students are expected to devote the class period to the lectures being delivered. At no time
during lectures should you be checking any electronic devises for email, texting or other such
activities. Instructors do, in fact, see what is going on in class and consider such activities rude
when she or he is delivering the material that they spent time organizing.
The instructor will allow the use of laptop computers in class for note taking only. If students
decide to check emails, update their Facebook page, or engage in other non-academic activities,
there will be a no-computer policy.
Students with Disabilities
If you are a student with a disability and believe you will need accommodations for this class, it
is your responsibility to contact Student Disability Services at (619) 594-6473. To avoid any
delay in the receipt of your accommodations, you should contact Student Disability Services as
soon as possible. Please note that accommodations are not retroactive, and that accommodations
based upon disability cannot be provided until you have presented your instructor with an
accommodation letter from Student Disability Services. Your cooperation is appreciated.
Course Outline
The following topics and assigned readings give a general outline of the class content. Some important
material will be provided in lecture that is not included in the Rauber text, which adds to the importance
of attending class faithfully.
I Composition and Structure of Atmosphere (Chapter 1)
A. Temperature
1. relation to heat
2. thermal layering
B. Pressure
C. Moisture
D. Winds
-3II Weather Measurements (Chapters 2)
A. Organization and History of the National Weather Service
B. Surface Measurements
C. Direct Upper Air Measurements
D. Doppler Radar and Wind Profiling
E. Satellites
F. Commercial Aircraft Measurement
G. National Lightning Detection Network
III. Weather Maps (Chapter 3)
A. Surface
1. Station Models
2. isobars, isotherms and fronts
B. Upper-Level
1. constant pressure maps
IV. Forecasting Severe Weather (Chapter 4)
A. Numerical Models
B. Phases of Model Prediction
C. Inherent Shortcomings of Models
D. Ensemble Forecasting
V. Atmospheric Stability (Chapter 6)
A. Buoyancy
B. Lapse Rates
C. Lifting Condensation Level and Level of Free Convection
D. Lifting Mechanisms
E. Vertical Changes in ELR
VI Atmospheric Forces (Chapter 7)
A. Pressure Gradient, Gravitational and Coriolis Forces
B. Newton’s Laws of Motion
C. Hydrostatic and Geostrophic Balance
D. Formation of Jet Stream
VII. Cyclones and Anticyclones (Chapter 8)
A. Force Imbalances
B. Curved Flow
C. Jet Streaks
D. Friction Layer
E. Dynamic and Thermal Lows
VIII. Air Masses and Fronts (Chapter 9)
A. Characteristics and Formation of Air Masses
B. Fronts and Dry Lines
C. Upper-Level Fronts
D. Identification of Fronts on Weather Maps
E. Cold Air Damming
-4IX. Midlatitude Cyclones East of the Rocky Mountains (Chapter 10)
A. Initial Development and Movement
B. Weather Associated with Early Stages
C. Storm Intensification
D. Associated Upper-Air Patterns
E. Impacts of Climate Change
F. Societal Effects of Eastern Midlatitude Cyclones
X. Midlatitude Cyclones Forming Along North American Coasts (Chapter 11)
A. East Coast Cyclones
1. Pre-storm environment
2. Initial Development
3. Weather Conditions and Storm Evolution
B. Gulf Coast Cyclones
1. Eastern storm track
2. Mississippi-Ohio Valley storm track
C. Forecasting Coastal Storms
D. Coastal Erosion and Societal Impacts
E. Coastal Cyclones and Global Warming
XI. Freezing Precipitation and Ice Storms (Chapter 12)
A. Ice and Supercooled Water
B. Vertical Structure of Atmosphere during Freezing Precipitation
C. Weather Patterns Associated With Freezing Precipitation
D. Forecasting Freezing Precipitation
E. Distribution of Freezing Precipitation in North America
F. Freezing Precipitation and Global Warming
G. Societal Impacts
1. Aviation Disasters
2. Economic Effects
XII. Lake-Effect Snowstorms (Chapter 13)
A. Pattern
B. Development
C. Climatology
D. Cloud and Precipitation Pattern
E. Snowfall Enhancement
F. Examples and Economic Impacts
G. Lake Effect Snow and Global Warming
XIII. Cold Waves (Chapter 14)
A. Formation of Cold Air Masses
B. Movement of Air Masses into Middle Latitudes
1. North America
2. Eurasia
C. Wind Chill Index and Advisories
D. Economic Impacts and Fatalities
E. Cold Waves and Global Warming
-5XIV. Great Plains Blizzards (Chapter 15)
A. Colorado Cyclones and Blizzards
B Alberta Clippers
C. Ground Blizzards
D. Human Safety Procedures
E. Blizzards and Global Warming
XV. Mountain Snowstorms (Chapter 16)
A. Source of Snowstorms
B. Characteristics over Individual Ranges
C. Global Warming and Dwindling Water Supplies
XVI. Mountain Wind Storms (Chapter 17)
A. Dynamics of Downslope Winds
B. Rocky Mountain Chinooks
C. Santa Ana Winds
D. Katabatic Winds
E. Societal Effects: Aviation threats and Effects of Rapid Temperature Fluctuations
F. Mountain Windstorms and Climate Change
XVII. Lightning and Thunderstorms (Chapters 21 and 18)
A. Lightning Formation
B. Related Phenomena
C. Lightning Safety
D. Types of Thunderstorm Systems
E. Thunderstorms and Global Warming
XVIII. Tornadoes (Chapter 19)
A. Formation in Supercells
B. Formation in Non-Supercell Thunderstorms
C. Tornado Detection and Forecasting
D. Tornado Safety and Fatalities
1. Distributions
2. Temporal and Geographic Changes in Tornado Fatalities
XIX. Hailstorms (Chapter 20)
A. Hail Embryo Formation
B. Hail Stone Growth
C. Hailstorm Forecasting
D. Detection Using Radar
E. Geographic Distribution and Impacts
F. Human Attempts at Hail Suppression
XXI. Downbursts (Chapter 22)
A. Formation
B. Conducive Atmospheric Conditions
C. Downburst Structure
D. Types of Microbursts
E. Human Activities
1. Aviation Disasters
2. Research and Modern Detection
3. Forecasting
-6XXII. El Niño/La Niña and the Southern Oscillation (ENSO): (Chapter 23)
A. Walker Circulation and Ocean Conditions
B. Evolution of an ENSO event
C. Effects of El Niño on Atmosphere
1. changes in jet stream, precipitation and wind patterns
2. economic impacts
D. La Niña Phases
E. Monitoring ENSO and Current Research
F. ENSO and Hurricane Activity
XXIII. Tropical Cyclones (Chapter 24)
A. Typhoons, Cyclones and Hurricanes: Worldwide Occurrence
B. Hurricane Tracks
C. Hurricane Structure
D. Tropical Cyclone Development
1. Trigger mechanisms for thunderstorms
2. Environment required for cyclone formation from thunderstorm clusters
3. How thunderstorms organize in hurricane
4. Source of Strong Rotating Winds
E. Destructive Forces
1. Storm surge
2. Flooding
3. Tornadoes
F. Forecasting
G. Potential Effects of Global Warming on Hurricane Activity
XXIV Floods (Chapter 25)
A. Types
B. North American Patterns
C. Forecasting and Safety
D. Impact of Global Warming
XXV. Drought (Chapter 26)
A. Indices of Drought
B. Causes
C. Drought in the U.S.
1. Central
2. Eastern
3. Western
XXVI. Heat Waves (Chapter 27)
XX. Climate Change (Chapter 5)