<div class="eI2">Fog Stability Index</div>
This is a stability index for fog formation. It is from 2WW/TN-79/008, &quot;A New Technique for Forecasting the Occurence of Fog and Low Stratus Ceiling by Use of a Flow Chart&quot;.<br>
The equation for the index is:<br>
<b><i>Fog Stability Index</i> = 2*(t<sub>s</sub> - t<sub>850</sub> + t<sub>s</sub> - t<sub>ds</sub> ) + W<sub>850 </sub>=</b><br>
=4t<b><sub>s</sub> - 2(t<sub>850</sub> +&nbsp;t<sub>ds</sub>) + W<sub>850</sub></b><br>
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