The snowshowers shown here were associated with the early phases of a storm system that affected northern New Mexico from January 12-14, 2007. There was no thunder associated with these snowshowers, although farther to the southeast in NM in the warmer air, thunderstorms (with rain) did occur.
The first picture shows one of the snowshowers as it passed southeast of Santa Fe a little before sunset:
The next picture is a more zoomed image of the glaciated top of the snowshower:
This snowshower even had mammatus under the anvil, which was being blown downshear:
Finally, here is another snowshower approaching from the southwest:
Note that many of its features actually resemble a supercell thunderstorm. As with the previous shower, the anvil is being blown downshear (to the left, or east). At the right (the northwest side of the snowshower, which was moving east) you can see a hard updraft tower, and if you look at the top near the center of the shower, you can actually see a bit of an overshooting top (partially obscured by lower, closer clouds).
These snow showers were moving very quickly, and although they produced short intense bursts of snow, especially when moving over higher elevations, they did not produce a lot of accumulation. I was skiing at Ski Santa Fe earlier in the day when a couple of them passed over, and the peak snowfall rates were certainly in excess of an inch an hour, although none of them lasted that long. Over the course of the day, the ski area got an inch or two of snow.
This activity continued intermittently for a couple days, before morphing into more widespread snow early the morning of the 14th. The city of Santa Fe got about 2 inches of snow, but all of the ski areas in northern New Mexico had storm totals in excess of a foot, with 19 inches at Ski Santa Fe over the duration of the storm.