The Interaction of Precipitation with Orography (IPRO)

June 5-16, 2017

NCAR Mesa Lab


NCAR Organizers: 

Chair: Rich Neale - CGD

Julio Bacmeister - CGD

Peter Lauritzen - CGD

Angie Pendergrass - CGD

Roy Rasmussen - RAL

Joe Tribbia - CGD

University Organizers: 

Bill Boos - Yale University

Dale Durran - University of Washington

Jan Lenaerts - Utrecht University

Brian Mapes - University of Miami

Cliff Mass - University of Washington

Jennifer Neale - Denver Botanic Gardens

Kristen Rasmussen - Colorado State University


Participants will learn from international speakers with observational and modeling expertise across the range of the orographic precipitation environment. Practical exercises using both the Community Earth System Model (CESM) and the Weather Research and Forecasting model (WRF) will form the foundation for understanding the orographic precipitation processes in models.


Tutorials and computer-based exercises will provide experience with a broad range of material, extending across the sub-disciplines of theoretical flow over orography, observational case studies, simple models, moist physical processes, the representation of precipitation-orography interactions in forecast and climate models, and smaller-scale applications.

This colloquium will be held at the National Center for Atmospheric Research in Boulder, CO, USA. In addition to receiving excellent scientific training, participants will have the opportunity to explore the National Center, will receive guidance on career planning and professional development, and have access to additional seminars and activities at the Center, if time allows.


Motivation and Timeliness:

Precipitation near significant orography has many climatological, terrestrial and human impacts. Gradients in orographic height lead to large variations in precipitation, land-surface type, vegetation and watershed properties. Dramatic flooding events linked to orography can also impact the local ecosystem and human activity. A complete understanding of the interactions among all these systems is key but remains illusive.

Expected Outcome:

University researchers will gain an understanding of the role of the key precipitation-orography interactions. This will be a combination of the observed properties, and the challenges of representing these processes and interactions in short-term forecast and climate models.


The NCAR Advanced Study Program will fund travel and living expenses for ~25 participants during the colloquium. International students are encouraged to apply.


If you have questions about this colloquium please contact the ASP office at