As the snow melts and your lawn starts to show again, you may notice that the grass looks funny. It is probably matted and look like it has a gray or brown appearance. For those of us in the North, it is most likely caused by Gray Snow Mold, a fungus that is enhanced by extended periods of snow or leaf cover.
Aggressive raking to break up and remove this dead leaf tissue will allow more sun and air to get to the live portions of the grass plant and promote quicker recovery of both the health and appearance of your lawn. Sure it is hard work, but your lawn will thank you later.
I like to follow this up with a good rolling. I roll for two reasons: #1, and most obvious, is that it smooths the lawn, and #2 it gently pushes the crown of the turf plant back into the soil where it will be better protected from some of the harsh conditions it will face throughout the year.