Is it possible to achieve the following shadow effect in CSS?

It needs to go below an image/div.
The closest I have got so far is using
-webkit-box-shadow: 0px 20px 15px -10px #999;
-moz-box-shadow: 0px 20px 15px -10px #999;
box-shadow: 0px 20px 15px -10px #999;
This might not be a shadow per se, but I just generated this as a
backgroundvia Ultimate CSS Gradient Generator