Thunderstorm at sunset.

High-based thunderstorm over southeastern New Mexico.

Cumulus over the Painted Desert, Arizona.

Thunderstorm anvils and mammatus at sunset.

Towering cumulus over the Florida Keys.

Thunderstorm with a circular anvil near Brighton, Colorado.

Hailstorm and smoke plume over Denver, Colorado.

Needle funnel in anvil of an eastern New Mexico thunderstorm.

Cumulonimbus mammatus over Boulder, Colorado.

Cumulonimbus mammatus over western Kansas.

Cumulonimbus mammatus over western Nebraska.

Cumlonimbus mammatus over western Kansas.

Cumulonimbus mammatus over northern Arizona.

Cumulus towers over eastern New Mexico.

Towering cumulus behind the San Fransciso Peaks, northern Arizona.

Cumulonimbus with ranch house and windmill in western Kansas.

Cumulonimbus with horizontal vortex in anvil.

Thunderstorm with pileus in northern Arizona.

Thunderstorm anvils and mammatus at sunset.

Thunderstorm anvils and mammatus at sunset.