Showalter Index Calculator

Severe Thunderstorms Tonight in the Mid-Atlantic; Tropical Storm Bertha in the Gulf

Scattered thunderstorms with severe gusts, hail and a tornado risk are possible near a cold front from the Ohio Valley to the Mid-Atlantic tonight. Tropical Storm Bertha is expected to bring tropical storm conditions to portions of the Gulf Coast from the panhandle of Florida into Louisiana through Wednesday. Read More >

Showalter Index

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What does my answer mean?

Showalter Index greater than 0: Stable, but weak convection possible for SI = 1-2 if strong lifting is present.
Showalter Index between 0 and -3: Moderately unstable.
Showalter Index between -4 and -6: Very Unstable.
Showalter Index between less than -6: Extremely Unstable.

Severe Thunderstorms Tonight in the Mid-Atlantic; Tropical Storm Bertha in the Gulf

Showalter Index

by Tim Brice and Todd Hall

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