I learned how to make a storm, and this is how you do it:
HTML:<div class="stormy"></div>
CSS:
/* STORMY */
.stormy {
animation: stormy 5s ease-in-out infinite;
background: #222222;
border-radius: 50%;
box-shadow:
#222222 65px -15px 0 -5px,
#222222 25px -25px,
#222222 30px 10px,
#222222 60px 15px 0 -10px,
#222222 85px 5px 0 -5px;
height: 50px;
width: 50px;
margin-left: -60px;
position: absolute;
left: 947px;
top: 70px;
}