Severe and Unusual Weather


Fall 2017

Severe and Unusual Weather (3 credits):

Section 1
MWF 2:30 pm - 3:20 pm
60 Willard Bldg.

Dr. David R. Stauffer
Professor of Meteorology
621 Walker Bldg
Office Hours: after class and by appointment

TAs: Jon Seibert,
Office Hours – Th 3-4 pm, 626 Walker Bldg.

Chris Yu
Office Hours – Wed 10-11 am, 402 Walker Bldg.

CANVAS:  This course will heavily utilize the CANVAS learning management system for distribution of Powerpoint lecture slides and homework assignments. You should get in the habit of checking CANVAS before each class to view any lecture / assignment materials. Any changes to the syllabus shall also be given to the student in written (paper or electronic) form.

Required Text: There is no required text for this course.  Course slides are organized into units and posted on CANVAS.  Some course content will be provided in class and not via slides posted to CANVAS.  Class attendance is expected and VERY important.

Academic Integrity: Students in this class are expected to work the exams and quizzes on their own.  They should hand in the solutions to homework problem sets showing all steps and written in their own words. Students are not to copy exam or quiz answers from another person's paper and present them as their own.  (Please see: Earth and Mineral Sciences Academic Integrity Policy:, which this course adopts.) To learn more, see Penn State's "Plagiarism Tutorial for Students."

Course Copyright: All course materials students receive or to which students have online access are protected by copyright laws. Students may use course materials and make copies for their own use as needed, but unauthorized distribution and/or uploading of materials without the instructor’s express permission is strictly prohibited. University Policy AD 40, the University Policy Recording of Classroom Activities and Note Taking Services addresses this issue. Students who engage in the unauthorized distribution of copyrighted materials may be held in violation of the University’s Code of Conduct, and/or liable under Federal and State laws.

For example, uploading completed labs, homework, or other assignments to any study site constitutes a violation of this policy.

Accommodations for Students with Disabilities: Penn State welcomes students with disabilities into the University's educational programs. Every Penn State campus has an office for students with disabilities. The Student Disability Resources (SDR) website provides contact information for every Penn State campus: ( For further information, please visit the Student Disability Resources website (

In order to receive consideration for reasonable accommodations, you must contact the appropriate disability services office at the campus where you are officially enrolled, participate in an intake interview, and provide documentation: If the documentation supports your request for reasonable accommodations, your campus’s disability services office will provide you with an accommodation letter. Please share this letter with your instructors and discuss the accommodations with them as early in your courses as possible. You must follow this process for every semester that you request accommodations.

Attendance: This course abides by the Penn State Attendance Policy E-11:, and Conflict Exam Policy 44-35: Please also see Illness Verification Policy:, and Religious Observance Policy: Students who miss class for legitimate reasons will be given a reasonable opportunity to make up missed work, including exams and quizzes.  Students are not required to secure the signature of medical personnel in the case of illness or injury and should use their best judgment on whether they are well enough to attend class or not; the University Health Center will not provide medical verification for minor illnesses or injuries. Other legitimate reasons for missing class include religious observance, military service, family emergencies, regularly scheduled university-approved curricular or extracurricular activities, and post-graduate, career-related interviews when there is no opportunity for students to re-schedule these opportunities (such as employment and graduate school final interviews).  Students who encounter serious family, health, or personal situations that result in extended absences should contact the Office of the Assistant Vice President for Student Affairs (AVPSA) and Student Care and Advocacy for help:  Whenever possible, students participating in University-approved activities should submit to the instructor a Class Absence Form available from the Registrar's Office:, at least one week prior to the activity.

Weather Delays: Campus emergencies, including weather delays, are announced on Penn State News and communicated to cell phones, email, the Penn State Facebook page, and Twitter via PSUAlert (Sign up at: 

Reporting Bias-Motivated Incidents: Penn State takes great pride to foster a diverse and inclusive environment for students, faculty, and staff. Acts of intolerance, discrimination, or harassment due to age, ancestry, color, disability, gender, gender identity, national origin, race, religious belief, sexual orientation, or veteran status are not tolerated ( and can be reported through Educational Equity via the Report Bias webpage.

Counseling and Psychological Services: Many students at Penn State face personal challenges or have psychological needs that may interfere with their academic progress, social development, or emotional wellbeing.  The university offers a variety of confidential services to help you through difficult times, including individual and group counseling, crisis intervention, consultations, online chats, and mental health screenings.  These services are provided by staff who welcome all students and embrace a philosophy respectful of clients’ cultural and religious backgrounds, and sensitive to differences in race, ability, gender identity and sexual orientation.  Services include the following:

            Counseling and Psychological Services at University Park  (CAPS): 814-863-0395
            Counseling and Psychological Services at Commonwealth Campuses
            Penn State Crisis Line (24 hours/7 days/week): 877-229-6400
            Crisis Text Line (24 hours/7 days/week): Text LIONS to 741741

Severe and Unusual Weather: Students will learn about the fundamental principles that govern severe and unusual weather.  Concepts are taught in a descriptive manner without relying heavily on mathematics; thus the material is highly accessible to students with a wide variety of backgrounds.  The class will frequently draw on examples of significant historical and recent severe, hazardous or unusual weather events.  Students will be able to apply what they learned immediately to weather events occurring near their homes or around the world.  Students will better understand the nature and impacts of hazardous weather events so that they will be better equipped to make decisions and take action given certain weather information. The course will teach the student how to be a more savvy consumer of weather information.

The course will include discussion of mid-latitude and tropical weather features spanning spatial scales of thousands of kilometers down to a kilometer or less.  The course will begin with introductory material needed as background to understand relevant scientific concepts and frame the environments in which severe, hazardous and unusual weather occurs.  The major themes of the course are 1) warm-season weather involving different types of thunderstorms and convective systems, including supercells, tornadoes, hailstorms, hurricanes, and related strong winds, wind shears, downbursts, flooding, lightning, and 2)  cold-season phenomena including winter storms, blizzards, freezing and frozen precipitation, lake-effect snowstorms.  The course will also include an overview of special topics: computer modeling for numerical weather prediction and some applications that may surprise you!, hazard predictions including weather caused by mountains,  topographically-forced upslope-downslope flows, channeling, gravity waves, downslope wind storms, rotors and unusual atmospheric events including human impacts from activities such as deforestation, urbanization, enhanced greenhouse gas emissions, and finally different classes of atmospheric optical phenomena including rainbows, haloes and mirages.

Course Outline – Unit Topics

Unit 1 - Introduction, history of meteorology, tools of the trade – weather analysis and observations, in-situ vs. remotely sensed measurements, surface vs. above-surface (upper-air), instrumentation including automated surface observing system (ASOS),  rawinsonde, aircraft (ACARS), units, scales and mapping

Unit 2 - Radiation basics and remote sensing – solar & terrestrial radiation, greenhouse gases, convection, conduction, satellite and radar

Unit 3 - Temperature, pressure and water in the atmosphere – seasons, effect of ocean currents, elevation, hydrologic cycle, humidity, clouds, lifting/cooling, cloud condensation nuclei

Unit 4 - Wind basics and the jet stream – pressure gradient force, Coriolis effect, surface friction, upper-air mid-latitude jet stream, geostrophic balance, aviation concerns

Unit 5 - Linking surface and upper-air patterns – air masses, surface fronts, advection, high and low surface pressure systems, Norwegian cyclone model, upper-air troughs and ridges, vorticity, jet streaks, ‘upper-air support’

Unit 6 - Atmospheric stability, clouds and precipitation – dry and moist adiabatic lapse rates, cloud types, atmospheric boundary layer, air pollution, precipitation mechanisms


Warm-season weather:

Unit 7 - Thunderstorm basics – introduction to single-cell, multi-cell, supercell, updraft/downdraft

Unit 8 - Hailstorms, lightning and flash flooding – thunderstorm dangers, safety

Unit 9 - The general circulation and tropical weather systems – “big picture”, Hadley cell, trade winds, El Nino, La Nina, monsoons, ENSO, teleconnections

Unit 10 - Hurricanes – easterly waves, tropical depressions, tropical storms, storm surge

Unit 11 - Multi-cell thunderstorms – MCS, MCC, squall lines, bow echo, derecho, LEWP

Unit 12 - Supercells – rotating updraft / mesocyclone, hook echo, RFD, FFD

Unit 13 - Severe weather environments and tornadoes – Dry Line, Tornado Alley, storm chasing, tornado safety, Twister movie, Fujita scale (F scale), enhanced Fujita scale (EF scale)


Cold-season weather and special topics:

Unit 14 – Clippers, Nor’easters and lake-effect snow – Ben Franklin, blizzards, winter precipitation types, cold air damming, wind chill

Unit 15 - Numerical Weather Prediction (NWP) – weather forecasting, computer models and some surprising applications

Unit 16 - Human Impacts – deforestation, urbanization, urban heat island, enhanced greenhouse effect, climate change and global warming

Unit 17 - Atmospheric optics – you may see some things that you never knew existed, sky colors, rainbows, cloud bows, coronas, glories, haloes, parhelia / sun dogs, mirages

Class Format

Lecture Powerpoint slides and homework assignments will be posted on CANVAS, but be sure to come to class and bring a pencil and good eraser. The blackboard will also be used to expand on the material presented in the slides.  On some days, we will have a discussion of the current weather situation in which concepts covered during the course will be applied in “real life”.

Examinations and Grading

  • Exams I and II – 10 and 20%
  • Pop Quizzes - 10%
  • Final Examination - 30%
  • Homework - 30%

The exams and final will consist primarily of multiple choice, true/false and short answer questions and they are comprehensive in nature.  Exam II will focus on material taught since the previous exam.  Make-ups may be scheduled at the instructor's convenience for excused absences.  The make-up should be taken before the scheduled exam time, if at all possible.

Quizzes may be announced, but often will be a surprise.  They will generally be multiple choice, true/false or short answer questions that deal with the recent material.  Please be sure to bring a pencil or pen to class, and don't be late! Quizzes cannot be made up but there will be a minimum of one drop allowed depending upon the final number of quizzes.

Note also that the homework assignments are worth 30 % of your total grade, and this is equal to the sum of the first two exams!   Homework will generally be due at least one week from when it was assigned, and TA help is available!  There are seven homework assignments planned for this 15-week course. Late assignments will be penalized unless there is a good reason for being late.