Why can it rain for sevral hours at 37 degrees and snow at 37 degrees?
You have to look at the upper atmosphere; while it was 37 at the ground, the cold layer was deepening, resulting later on with some quickly melting snow later in the evening. Look at the cold front like a wedge; the cold air undercuts the warm air. The precipitation when the cold front is moving through initially was all rain. As cold air filtered in replacing the warm air aloft, the altitude where the freezing temperature was located at slowly fell, allowing some flakes to make it to the ground as heavier, wetter (melting) snow.
