The snow in your photo is gray, not white.
That indicates the photo is under exposed.
DSLR in camera reflected light meters are calibrated based on the very valid assumption that the vast majority of scenes have an average reflectance that is in the same range as 12% to 18% gray.
When a scene has a lot of white in it, the increased reflectance causes the camera to deliver an under exposed shot unless the photographer dials in some exposure compensation .
Usually 2/3 of a stop (0.7 EV) more exposure suffices.
A couple other points:
You can use the camera's histogram function on the rear LCD to gauge exposure accuracy:
The monochrome (B&W) option in most DSLR cameras deliver images that lack contrast because the image is made by just de-saturating the original color image.
High quality B&W images are most often made post process from a Raw image data file.
Made in the camera B&W (monochrome) photos start out as a Raw image data file color image.
In this edit I have added a full stop of exposure (+1 EV), increased the mid-tone contrast, did some selective sharpening, and added a narrow black border: