they come up before the snow is gone

Chionodoxa luciliae perhaps.

Scilla siberica?

Tradescantia virginiana I think. (Blue spiderwort)

Here is a link that might be useful: Wikipedia link

Siberian squill.

I would second Scilla siberica. Chionodoxa flowers are facing upwards. Tradescantia would have some stems (plus they flower much later). Those are small/ narrow speciem, they should fill in with time and get few more flowers per stem. Do they get direct sun light when they flower?

Go with Scilla then. I spent a long time trying to decide between the two. But absolutely not Tradecantia.