Example of NWx paid radar - 5 minute updates, NMM overlays, 2 hour Hi-res playback, archived back a long way further etc. etc. (please note I'm not receiving any consideration for this plug from NetW, I just think it's a great tool to "see for yourself" exactly what's happening in the here and now with this type of setup! )
Current shot shows today's setup perfectly with the help of the overlays. A low centred over mid wales is dragging warm air up over the cold air to the north on its NE flank. An occluded front (The warm air is floating over the cold air and does not touch the ground) is running roughly through the Scotish borders east to west. As more warm air is pushed into this system it rises over the cold air, the warm air cools with altitude and pressure drop, its moisture condenses out and immediately freezes falling as snow. I suspect this feature is so weak now that the warm and cold air is almost mixed out giving the slight thaw currently being witnessed in some places. The track of this low (where it goes next) will dictate the weather for the next few hours. Latest 06Z GFS has it heading towards the NNW and merging with the larger LP system out to the west of Ireland that is trying to slide towards the SSE.