Altostratus up close

Climbing through altostratus northeast of Phoenix, Arizona - Photo by Craig Johnson ON February 13, 2018

Climbing out of Phoenix on an American Airlines flight to Des Moines, we passed through scattered cumulus clouds (visible below) before reaching what appeared to be a well defined altostratus layer. As we approached the cloud base it became apparent the cloud base was diffuse - not distinct. The altostratus looks like fog covering roughly the top half of the photo. The lower clouds look indistinct because we were climbing into a thicker cloud layer which eventually obscured the lower clouds.