Here in Surbiton, the cars were covered in thick frost this morning, but with I would estimate random 5mm blobs distributed over them also, and I wondered if it could have been the briefest of flurries overnight. BTW, still waiting for decent snowfall in this part of SW London - so far it has fallen for a couple of hours yet come to very little, or fallen for 20 minutes then vanished.... third time lucky? I have a ten year-old who is becoming as obsessed with lamp post watching as me:)