Value Sketch for New Landscape

This is a value or tonal sketch I did a couple days ago for a landscape painting I am hoping to work on this week.  I used a gray toned sketch pad and dark gray and black ink pens, and a white chalk pencil.  I would like to try doing this painting primarily with a palette knife.

Below is the reference photo for the painting.  I took the photo while in New Hampshire last month.  The colors of the reeds and the snow were much more vibrant.  I hope I can remember them and reproduce them.