Why can you sometimes see sunshine coming through clouds, but can't see them other times? (pix included)?

Question

What makes that happen?

Like these -

http://www.freefoto.com/images/15/78/15_78_6---Rays-of-Sunshine-against-a-dramatic-black-sky_web.jpg

http://www.freefoto.com/images/15/78/15_78_4---Rays-of-Sunshine-against-a-dramatic-black-sky_web.jpg

http://pro.corbis.com/images/RF248187.jpg?size=572&uid=%7B0D17C1D7-1040-42FA-8951-C36D10EB9996%7D

http://www.lightandmatter.com/html_books/5op/ch01/figs/crepuscular-rays.jpg

http://nihongo.wunderground.com/data/wximagenew/h/HoustonSmaug/54.jpg

Answer 1

That's because there is a small opening in the clouds. So (as you can very clearly see in the 3rd picture) the sunlight shines through. This typically happens when the sun is setting or almost set and a storm is coming in because the rest of the sky is dark except for the ray of sunshine that is visible. The reason you do not see the actual sun when this occurs is because the cloud covers the actual sun, but is close enough to uncovering the sun to let the light be very clear and visible.

Answer 2

Abbers is pretty much correct, and I wanted to mention that this phenomenon occurs with cumulus/stratocumulus and sometimes altocumulus clouds. The clouds must be thick enough to block out sunlight. The sunlight shining down through the breaks between these thick clouds is called a "crepuscular ray".

It happens to be one of my favorite weather phenomenons. It looks majestic!

Answer 3

abbers  and tami took the answer straight out of my mouth