Storm types#supercell#uk
HP supercell (High Precipitation)
At a glance
A supercell whose mesocyclone is wrapped in heavy rain. You can't see what's inside — which makes them both the most common UK variant and the most dangerous to chase.
Deep dive
HP supercells form when precipitation efficiency is high — usually because PWAT is elevated and/or the storm has ingested rain-cooled inflow. Visual clues: a rain-free base that's partially obscured, rain bands curling into the updraft (the 'beaver tail'), and a mesocyclone that you can't actually see.
Hazards: rain-wrapped tornadoes, giant hail appearing out of the curtain, and sudden RFD outflow. UK supercells almost always trend HP because our boundary layer is moist and the shear profile tends to be uniform rather than strongly veered.