After about 10 seconds, this is how the snowflakes looked. There is already some melting and fine features are being lost.
A few more seconds, and the melting is accelerating.
A little later...
...and finally a nice exercise in looking at water under the microscope! I don't think the liquid water is quite as interesting as the frozen stuff. It typically took about 40 seconds to go from 15°F snowflakes to liquid, so you don't want to dally through the process. The 40 seconds could probably be stretched a bit if you didn't have an incandescent bulb providing light and heat less than a foot from the microscope. Next time, maybe we'll try a flashlight or a fluorescent bulb. In the meantime, I'll gladly put on the boots and gloves and enjoyed a longer viewing cycle outdoors.