Changes in orographic precipitation patterns caused by a shift from snow to rain
Article first published online: 25 SEP 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 18, September 2012
How to Cite
2012), Changes in orographic precipitation patterns caused by a shift from snow to rain, Geophys. Res. Lett., 39, L18706, doi:10.1029/2012GL052741., , , and (
- Issue published online: 25 SEP 2012
- Article first published online: 25 SEP 2012
- Manuscript Accepted: 8 AUG 2012
- Manuscript Revised: 7 AUG 2012
- Manuscript Received: 14 JUN 2012
- Sierra Nevada;
- climate change;
- regional climate model
 Climate warming will likely cause a shift from snow to rain in midlatitude mountains. Because rain falls faster than snow, it is not advected as far by prevailing winds before reaching the ground. A shift in precipitation phase thus may alter precipitation patterns. Using the Weather Research and Forecasting (WRF) regional climate model at 27-9-3 km resolutions over the California Sierra Nevada, we conducted an idealized experiment consisting of a present climate control run and two additional simulations in which (a) fall speed for snow is similar to rain and (b) all precipitation is constrained to fall as liquid. Rather than simulating future climates directly, these perturbation experiments allow us to test the potential impacts of changing precipitation phase in isolation from other factors such as variable large-scale atmospheric circulation. Relative to the control, both perturbations result in a rain shadow deepened by ∼30–60%, with increased focusing of precipitation on the western Sierra Nevada slopes best resolved at ≤9 km resolutions. Our results suggest that altered precipitation phase associated with climate change will likely affect spatial distributions of water resources, floods, and landslides in the Sierra Nevada and similar midlatitude mountain ranges.