<a href="https://en.wikipedia.org/wiki/Cumulus" class="extiw" title="en:Cumulus">Cumulus</a> cloud with <a href="https://en.wikipedia.org/wiki/pileus" class="extiw" title="en:pileus">pileus</a> cap. Taken 2007-04-27 from a <a href="https://en.wikipedia.org/wiki/Glider_aircraft" class="extiw" title="en:Glider aircraft">glider</a> flying in <a href="https://en.wikipedia.org/wiki/mountain_wave" class="extiw" title="en:mountain wave">mountain wave</a> over the <a href="https://en.wikipedia.org/wiki/Ridge_and_Valley_Appalachians" class="extiw" title="en:Ridge and Valley Appalachians">Ridge and Valley Appalachians</a> of south central <a href="https://en.wikipedia.org/wiki/Pennsylvania" class="extiw" title="en:Pennsylvania">Pennsylvania</a> USA near <a href="https://en.wikipedia.org/wiki/Bedford,_Pennsylvania" class="extiw" title="en:Bedford, Pennsylvania">Bedford</a>. View is looking southwest with a northwest wind, so the wind is blowing from right to left in the photo.
<a href="https://en.wikipedia.org/wiki/User:Dhaluza" class="extiw" title="en:User:Dhaluza">User:Dhaluza</a>
CC BY 2.5
<span class="int-own-work" lang="en">Own work</span>