1 Clouds like this are known as multi-layered clouds. Notice all the darker gray color elsewhere in the image. In this image, the darker the color, the lower the clouds are to the ground. So what we have are higher clouds on top of lower clouds, hence the name multi-layered clouds. These are an indicator that there is not just moisture at the surface, but moisture well up in the atmosphere as well.
Winter storms adore an atmosphere that is basically saturated from the ground all the way up.
Multi-layered clouds are a good indicator that the atmosphere is indeed very saturated. It is not unheard of at all to have a phenomena known as thundersnow to occur. When convective snow falls, it often falls at rates well over 2 inches per hour. Thus, this is a very reliable rule. The other point to make is that the low pressure center is to the south-southwest of Rapid City.