Elevated convection is a storm whose updraft is fed by an unstable layer above a stable near-surface layer, so the parcels doing the work sit aloft rather than at the ground.
How it forms
When a stable layer sits at the surface, either from radiational cooling at night, from the cool side of a warm front, or from a thunderstorm outflow undercutting the region, parcels lifted from the ground are colder than their surroundings and cannot rise freely. Instability higher up can still be tapped, though. Isentropic ascent along a warm front, upglide over a shallow cold dome, or forced ascent over an outflow boundary lifts parcels from a layer above the stable air and can turn them convective if the layer aloft is buoyant enough.
The buoyancy source in that setup is not the surface. It is the elevated mixed layer or the moist layer sitting above the inversion, and the parcel that matters is the most-unstable parcel from that layer. In the sounding, most-unstable CAPE (MUCAPE) is present even when surface-based CAPE is small or zero, and the LFC and LCL for that parcel sit hundreds or thousands of meters above the ground.
How forecasters use it
Elevated convection is diagnosed from the sounding profile more than from the radar. When MUCAPE is meaningful but SBCAPE is near zero, and the storm base is clearly aloft rather than reaching the ground, the storm is elevated. Nocturnal complexes on the cool side of a warm front, mid-level moist absolute instability regions, and cold-side-of-front storms in the cool season are the textbook cases.
Hazard framing shifts for elevated storms. Large hail remains a real threat because the ice growth zone aloft can still be worked hard by an elevated updraft, and heavy rain is often the dominant impact because efficient warm-rain processes can operate in the elevated moist layer. Damaging surface winds and tornadoes are less common because the storm's strongest circulations do not reach the ground through the stable layer, though outflow winds and downbursts can still descend when momentum is transported down through the stable air.
Important limits
Elevated is not a permanent state. Elevated storms can become surface-based as the low-level stable layer erodes, either through daytime heating or through outflow-induced destabilization. When that transition happens, the tornado and severe wind risk can rise quickly because the strong updraft aloft suddenly has direct access to boundary layer air.
The label also depends on where the beam or the profile is looking. A storm can be surface-based on the warm side of a front and elevated 50 kilometers north as the same air mass crosses the boundary. Read the near-storm environment locally, not by category, and treat the surface-based versus elevated distinction as a working hypothesis that must hold together with the parcel choice, the boundary layer profile, and the visible storm base.