Horizontal Icicles

April 07, 2016


Photographers: Craig Stith; Doug and Janet Stith 
Summary AuthorDoug Stith; Jim Foster

CaptureThese intriguing horizontal  were captured on a signpost in Fort Collins, Colorado, following near-blizzard conditions on March 23, 2016. Strong winds (40 mph or 64 kmph), very moist air and slightly below freezing temperatures (near 30 degrees F or -1 C) played major roles contributing to the icicles' formation. Apparently, ice formed in holes on the inside of the metal signpost and was forced through the holes by the wind. You can see on the enlarged photo at left that the icicles are positioned along the right side of the holes. The wind continued to push the moist air through the left sides of the holes, extending the length of the icicles that had already formed by the process of accretion. Note that there is minimal tapering of the horizontal ice unlike what's normally observed with vertical icicles.

Photo Details: Top - Camera Model: iPhone 6; Focal Length: 4.15mm (35mm equivalent: 29mm); Aperture: ƒ/2.2; Exposure Time: 0.0003 s (1/3597); ISO equiv: 32. Inset: same except - Exposure Time: 0.0004 s (1/2475).