Mountain-wave clouds add drama to a Nederland sunrise on 17
October. The clouds, which are more prevalent during the cooler
months of the year, are formed as westerly upper-level winds
pass over the Front Range. As they ascend the peaks, the winds
often strengthen due to the Bernoulli effectthe same
phenomenon that makes winds accelerate as they're funneled
between downtown skyscrapers. If a stable layer of air lies
close to mountaintop level, a wave can become trapped in it.
Such waves often leave sculpted clouds in their wake along and
just east of the foothills. Our wave clouds are most dramatic
from fall through spring, when the polar jet stream often flows
across Colorado. A diagram of the mountain-wave process can be
found in the on-line version of the
Walter Orr Roberts Weather Trail.
(Photo by Carlye Calvin.)|
Unless otherwise noted all images are copyrighted by the University Corporation for Atmospheric Research / National Center for Atmospheric Research / National Science Foundation.