Encore - Geelong Roll Cloud

December 30, 2017

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Today and every Saturday Earth Science Picture of the Day invites you to rediscover favorites from the past. Saturday posts feature an EPOD that was chosen by viewers like you in our monthly Viewers' Choice polls. Join us as we look back at these intriguing and captivating images.

Photographer: Phil Thomson 
Summary Author: Phil Thomson; Jim Foster

August 2012 Viewer's Choice This captivating photo shows an Oz-like roll cloud approaching a yellow pebble road near the town of Geelong in Victoria, Australia. The late afternoon storm proved to be quite destructive as it tore through the Barrabool Hills area. Roll clouds are detached from the base of their parent cumulonimbus cloud. The winds accompanying such storms are straight-line as opposed to the tornadic winds associated with funnel clouds. While they're not always as fierce as they appear, this storm was as ugly as it looked. Photo taken on June 4, 2012.

Photo Details: Camera Maker: PENTAX; Camera Model: PENTAX K-5; Lens: Pentax 18-55 lens - 18mm; CPL and GND Filters; Focal Length: 18mm (35mm equivalent: 27mm); Aperture: f/8.0; Exposure Time: 0.167 s (1/6); ISO equiv: 400; Software: raw image edited in ACDSee Pro5.