Power Pacific system will continue to bring significant impacts for Pacific Northwest into northern California the remainder of the week. Dangerous coastal affects, heavy rain, flooding, strong winds, and higher elevation mountain snow continues. Meanwhile, a storm across the east is set to bring the first accumulating snow to many higher elevations of the Catskills into the central Appalachians. Read More >
Spokane, WA
Weather Forecast Office
On the afternoon of February 28th, Howard Lowell took these cloud pictures from Wenatchee, facing to thesoutheast. The obvious question is: what is causing the clouds to look like this? The unofficial name of thisphenomena is "Hole Punch" Clouds. If you use your favorite web browser and search for this phrase, you'llfind lots of web sites and photos.
The exact cause of these cloud formations is still a bit speculative. But the generally agreed upon theoryis this: Clouds are typically formed when air ascends, since it cools and the moisture in the air condensesinto cloud droplets. The Hole-Punch clouds are caused by descending air, which typically causes clouds todissipate. The cause of the descending air is thought to be from a higher cloud, or possibly from the exhaustof an airplane traveling above the cloud. In the picture below, you can even see some of what appears to bevirga (precipitation that evaporates before reaching the ground), the gray wisps just below and to the left ofthe street lamp. This lends to the idea that the air in this "hole" is descending.
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This picture actually shows the presence of another hole-punch cloud on the left-hand side of the picture nearthe mountains. This appears to have more of a hole in the clouds than the larger hole-punch cloud in the center of the picture.
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So, can you see these on satellite pictures? The answer is yes. The image below shows 2 "holes" just south ofWenatchee, and another to the east of Yakima. Click here to see an animation of the satellite imagery. |
US Dept of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
Spokane, WA
2601 N Rambo Rd.
Spokane, WA 99224
509-244-0110
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