Input Parameters

Results

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Dew Point
°F
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Temp-Dew Spread
°F
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Fog Risk
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Visibility Estimate
nm

Reference

Dew Point: Td = 237.7×γ/(17.27−γ) where γ = 17.27T/(237.7+T) + ln(RH/100) Fog likely when air-dew spread < 3°F AND warm air over cold sea Advection fog: warm moist air over cold water