CIN — Convective Inhibition
Also: CIN · cap
At a glance
CIN is the lid on the pot. Before a storm can fire, the atmosphere has to spend energy breaking through a warm layer aloft — and if the lid's too strong, nothing happens.
Deep dive
CIN is the negative-area equivalent of CAPE between the surface (or parcel origin) and the LFC. It's the energy the parcel must absorb before it's buoyant enough to rise on its own.
Weak CIN (0 to −25 J/kg) is easy to break via daytime heating or a front. Moderate CIN (−25 to −100 J/kg) usually needs a proper forcing mechanism — frontal lift, upper trough, outflow boundary. Strong CIN (<−100 J/kg) often means convection is effectively suppressed that day, even with huge CAPE.
A cap that breaks late is often a chaser's friend — it lets instability build undisturbed through the afternoon, then when storms finally initiate they explode into a sheared environment. A cap that never breaks is a bust.