Running in the falling snow can be fun. In fact, I enjoy it a lot. Usually, when the snow is falling, traction isn't too bad, so you can maintain your normal stride without too much problem. A day or two later, however (at least here in Northern Colorado), if the temperatures stay pretty cold, you are left with stretches of tracked and packed snow that offers poor footing and little or no traction, alternating with stretches that have been cleared and/or melted some, which are pretty good for running.
The slippery spots can really sap your energy, particularly if you are obsessed with maintaining a strong pace. Having poor traction forces you to use a lot of extra energy, and the poor footing forces you to proceed with some amount of trepidation and before you know it, your form stinks. If you're lucky, that doesn't turn out to be a big problem for you. For those of us who rely on good clean running form to alleviate the stresses that contribute to a variety of overuse syndromes, like ITBS, the slippery uneven surfaces can really become a problem.
I faced this problem on my run today. An eleven mile run was on the schedule, and I figured I could pretty easily accomplish this but about halfway in, I started to notice a familiar pain on the outside of my knee, and really had to focus on form to keep it in check. Still, now and then I'd fall out of my form when I'd hit the crossing of a street covered with uneven packed snow, or when I was forced to on stretches of road or sidewalk that was tracked and refrozen, and particularly when the surface was slippery, offering poor traction. The sense of poor traction really seems to cause me to get lazy with my form.
So, I finished the run all right, but has some ITBS pain in my right knee for a little while afterward. This is frustrating, because I know what I need to do with my form to prevent this problem, but conditions caused me to lose focus, and to my obvious detriment.
I'll probably either have to work on getting access to an indoor track or gym with a treadmill for my running on cold days for the rest of winter, or will just have to get creative with my training schedule (or maybe both.
We'll see how things play out. Wish me luck in keeping the ITBS at bay.