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Supercell composite parameter

From Wikipedia, the free encyclopedia
A map of the United States, with contours in blue representing the SCP and black tornado tracks representing EF5-rated tornadoes
The supercell composite index on April 27, 2011, overlaid with tracks of EF5-rated tornadoes (in black)

The Supercell Composite Parameter, often abbreviated as SCP, is a multi-parameter index used by the Storm Prediction Center that outlines areas of the United States where the development of supercell thunderstorms is favorable.[1] The parameter uses convective available potential energy, storm relative helicity and vertical wind shear to determine specific areas.[2] A value of 1 indicates a normal atmosphere while values above two are conducive for supercells.[3]

Equation

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Two equations can be used to conclude the supercell composite for an area:[3]

SCP = (⁠MUCAPE/1000 J/Kg^-1⁠) x (⁠0-3 km SRH/150 m^2s-^2⁠) x (⁠BRN denominator/40 m^2s-^2⁠)

SCP = (⁠MUCAPE/1000 J/Kg^-1⁠) x (⁠Effective shear/20 m^2s-^2⁠) x (⁠Effective SRH/50 m^2s-^2⁠)

See also

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References

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  1. ↑ "Mesoscale Parameters". National Weather Service. Retrieved 2026-05-04.
  2. ↑ "Climatology of the Supercell Composite Parameter (1979–2004)" (PDF). Oklahoma University. August 5, 2005. p. 2. Retrieved May 4, 2026.
  3. 1 2 "Utility of Severe Weather Parameters and Indices" (PDF). National Weather Service. 2017. pp. 28–29. Retrieved May 4, 2026.