The K Index


The K Index is the measure of thunderstorm potential based on the vertical temperature lapse rate, the moisture content of the lower atmosphere and the vertical extent of the moist layer.

As NASP, the following K Index values are guidelines:

    20 – 25 = Isolated thunderstorms

    26 – 30 = Widely scattered thunderstorms

    31 - 35 = Scattered thunderstorms

    35 and > = Numerous thunderstorms

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Insitute for Human and Machine Cognition
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