Category
Severe Weather Parameters
CAPE, shear, helicity, STP, and friends — what they mean on chase day.
Intermediate·9 min·Featured
What Is STP (Significant Tornado Parameter)?
STP combines CAPE, shear, helicity, and LCL into one number designed to flag environments capable of EF2+ tornadoes.
Intermediate·8 min
What Is CIN?
CIN — Convective Inhibition — is the lid on the atmosphere. Too much and nothing fires. Too little and you get a storm-cluttered mess.
Intermediate·10 min
What Is Storm Relative Helicity?
SRH measures how much the wind environment can spin an updraft. It is the parameter most directly tied to tornado potential.
Advanced·9 min
What Is Effective Shear?
Effective shear is a smarter version of bulk shear that accounts for the storm's actual inflow layer. It is the modern standard for supercell forecasting.
Beginner·10 min
What Is CAPE?
Convective Available Potential Energy is the atmosphere's fuel gauge. Here is what those J/kg numbers actually mean on a chase day.