Check out all the aerial pictures of the snow in the Sierra.
https://www.nytimes.com/interactive/2017/03/22/us/california-measuring-snowpack.html?src=recg&_r=1
Knowing with precision how much snow has accumulated is crucial for farmers and water managers.
Thats where a mapping project at NASA's Jet Propulsion Laboratory known as the Airborne Snow Observatory comes in. Using measurements gathered by specialized instruments on a plane, scientists have been able to gain an unprecedented understanding of the amount of water present in the Sierras snow.
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A geography lesson. Sierra is plural. We're sensitive about that and I always try to correct myself and use the proper form.
http://thehighsierra.org/sierra_or_sierras.htm
The Sierra Nevada is distinctly a unit, both geographically and topographically, and is well described as "una sierra nevada." Strictly speaking, therefore, we should never say "Sierras," or "High Sierras," or "Sierra Nevadas" in referring to it. Nevertheless, these forms are so frequently found in the very best works of literature and science that it would perhaps be pedantic to deny their admissibility. It becomes, therefore, a matter of preference, and for our part we rather like to keep in mind the unity of our great range by calling it simply "The Sierra" or "The Sierra Nevada."
