Nebraskaland

Nebraskaland July 2021

NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.

Issue link: http://mag.outdoornebraska.gov/i/1387349

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14 Nebraskaland • July 2021 IN THE FIELD By Martha Shulski THE RAIN THAT NEVER HAPPENED You may have noticed optically thin features that streak downward from the base of clouds and curve or hook to nearly horizontal. What you are witnessing is water that fails to reach the ground. Sometimes raindrops or ice crystals that exit a cloud submit to the sky and evaporate or sublimate. This is called virga. This phenomenon is more common in the arid climate of western Nebraska than in the humid east. Dryness and warmth help to vaporize the precipitation. Most often they are seen from mid- level clouds or high-base cumuliform clouds. As these droplets or crystals turn to vapor, they can sometimes lead to a strong but short-lived downdraft. Therefore, you may feel a rush of cool air while in the vicinity of virga. RADAR (radio detection and ranging) imagery can be fooled into thinking these droplets are precipitation and show a signature as such. Researchers have found that vaporizing precipitation is more than 30% in the world's major deserts and accounts for half of falsely detected precipitation in these areas. While virga percentages are not that high here in Nebraska, be on the lookout for the rain that never happened. Martha D. Shulski, at the University of Nebraska- Lincoln, is the director of the Nebraska State Climate Office. Virga over the Missouri River at Niobrara State Park. BROOKE TALBOTT, PLATTE BASIN TIMELAPSE

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