I was wondering the same thing...
I was expecting a "rain only" event this morning in Trowbridge, but at 8:00 it was snowing!
Temperature and Dew Point was also dropping... Temp was down to 1.5°c when I left.
Here in Bath (at the top of Lansdown), it's 0.5°c and still snowing, but pretty light.
However, it is starting to stick on the grass.
If we can hang on to this cold air, like you say, maybe something tonight/tomorrow???