Cumulonimbus Calvus and Pileus

These isolated multi-cellular cumulonimbus calvus clouds appeared in skies at Noelridge Christian Church in Cedar Rapids, Iowa on the evening of Thursday, July 7, 2011. The left panel shows a large bank of the calvus clouds in the north sky around 6:05 PM. Its center was located approximately 50 miles away, near the town of Oelwein in southern Fayette County. Cloud tops at places reached 35,000 feet. The right panel shows a calvus with a pileus cap. This cloud, shot at 5:50 PM, was located about 30 miles to the northeast, in southern Delaware County. Pileus are made of ice crystals high in the troposphere directly above another cloud. The pileus layer forms when the cumulus cloud thrusts a moist layer of air above it upwards, causing condensation in the layer. The cumulus cloud may eventually grow to penetrate the pileus layer.

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Early Warning

An EF2 wedge tornado is shown on the ground near the town of Early in northwest Iowa around 9:00 PM, Saturday, April 9, 2011. This view looks north from along Lee Avenue just north of US Highway 20 and about 2.25 miles SE of Early. The image is a video frame capture, seen courtesy of a lightning flash in pitch darkness, and therefore is of poor quality. It has been electronically enhanced to bring out brightness. As our storm chase team proceeded northeast from this location, we encountered our final tornado--another wedge just west of Nemaha, Iowa--around ten minutes later. We found ourselves a little too close to that one and just escaped being in its outer fringe, speeding away from it through driving rain and golf ball size hail. The overall chase produced a least a half dozen tornadoes viewed. *** The "F"-scale was introduced by Dr. Tetsuya "Ted" Fujita in 1971. In 2007 a new scale, Enhanced Fujita (EF), became operational. The old F-scale related the degree of damage to the strength of the wind but did not take into account the typical strengths and weaknesses of different types of building construction, which would become the measure of the new EF-scale. An EF2 tornado typically produces wind speeds up to 135 mph.

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Arachnid Cloud

Looking spider-like, this lone cloud is brilliantly tinted by the sun which had disappeared below the horizon about 15 minutes earlier. This photograph looks northwest over East Robins Road from near the grounds of Christ Community United Methodist Church in Marion, Iowa just after 9:00 PM on Saturday, July 2, 2011. The image was shot at 1/200 second, f/9 aperture, 320 ISO and 55mm focal length.

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Fireworks Moon

A fireworks burst sparkles the night sky beneath a waxing crescent moon and over the Newcastle Road neighborhood in Marion, Iowa just after 9:15 PM, Saturday, July 2, 2011.

This view looks west. The image was shot at 1/25 second at f/9, 320 ISO and 116mm focal length.

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Dazzling Day's End

Clouds in the northwest sky are painted and illuminated by the already-set sun at 9:05 PM, Saturday, July 2, 2011. Sunset on this day was 8:45 PM. The faint headlights of cars seen at lower left are on East Robins Road in Marion, Iowa.

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Moon 'n' Mercury

A waxing crescent moon and the planet

Mercury (upper right) are in close

proximity to one another in the WSW

sky around 9:10 PM, Saturday, July 2,

2011. The small dark puffs of smoke seen

at lower left are from spent firework

bursts. This image, shot at 1/30 second,

at f/9, 320 ISO, 55mm focal length, looks

over East Robins Road in Marion, Iowa.

The location of the camera was just west

of Christ Community United Methodist

Church, just off Alburnett Road.

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Dancing With The Stars

Stars appear to "dance" around the birch tree at lower right in this five-minute exposure captured at 11:25 PM, Tuesday, June 28, 2011. The image, shot at f/3.5, 320 ISO and 18mm focal length, looks northwest over Bowman Woods Park in Cedar Rapids, Iowa. The bright stars a center lower belong to the asterism "Big Dipper" in Ursa Major.

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