Mountain waves form above and downwind of topographic barriers and frequently pose a serious hazard to mountain aviation because of strong-to-extreme turbulence. This foundation module describes the features of mountain waves and explores the conditions under which they form. Like other foundation modules in the Mesoscale Primer, this module starts with a forecast scenario and concludes with a final exam. Rich graphics, audio narration, and frequent interactions enhance the presentation.
After completing this module, the learner should be able to do the following things.
With regard to the hazards, features, and climatology of mountain waves and downslope winds:
Identify at least 2 hazards associated with mountain wave activity
Recall at least 3 atmospheric and topographic requirements for a mountain wave system
Describe the major features of a mountain wave system
Recall when and where mountain waves and downslope winds occur
Recall the location of the following winds: Chinook, Santa Ana, Bora, and Foehn
With regard to downslope winds:
Recall characteristics of downslope winds
Describe why downslope winds are warm
With regard to the origin of mountain waves and downslope winds:
Describe why air displaced over a mountain range starts to oscillate
Recall the conditions that lead to topographically-blocked flow in terms of mountain height, wind speed, stability, and Froude number
Describe the effects of wind shear and inversions on mountain wave activity
Define critical level
Discriminate between a self-induced critical level and a mean-state critical level
Describe the different types of rotors and their associated atmospheric conditions
Identify which type of rotor is associated with more turbulence
With regard to forecasting mountain waves and downslope winds:
Recall the 1.6 rule-of-thumb
Recall what NWP model resolution is required to accurately depict mountain waves
Describe how a model's vertical coordinate system affects its ability to forecast mountain waves
Describe how radiosondes and pilot reports (PIREPs) can help with short-range forecasting of mountain waves
Describe how satellite imagery can be used to detect mountain wave activity with or without either daylight or clouds
In order to better serve our users and sponsors, access to our online materials requires registration. To learn more about registering or to get help with common questions about our site, please visit our FAQs.
Most of the material made available on MetEd is free for non-commercial, educational use. We encourage you to use our material to enhance your education and training efforts. To review the legal-speak with all the nitty gritty details, see our Legal Notices page.