Cumulonimbus Cloud Over the Rhone Valley
June 16, 2004
The photo above was taken near Ampuis, France on May 7, 2004 and shows an impressive cumulonimbus cloud towering over the Rhone Valley ("vallée du Rhône," Côtes-Roties). It appears that this storm cloud is in the anvil stage -- its top is spreading out along the tropopause. Because of the strong temperature inversion which exists at the tropopause (boundary between the troposphere and the stratosphere), billowing cloud turrets tend to move laterally along this boundary. Intense rainfall, hail, strong winds and or vivid lightning frequently accompanies well developed cumulonimbus clouds.