With regard to convection and cloud cover, this seems to be a deciding factor for the potential development of showers off the North Sea.
Excuse me for not recalling the date, but one of our heavier falls of snow in January started as convective showers moving in from the SE and when the front moved in from the SW later in the day, the convection appeared to enhance the precipitation as the two merged. Wouldn't this be a possibility rather than the cloud cover just being limiting, or does the band of precipitation moving in need to be closer to the convection? Excuse my lack of technical knowledge.