What conditions favor radiation fog?

Answer 1

1. High humidity: a temperature dew point "spread of 4 degrees" or less
2. Calm wind: "less than 5 knots" moist air remains concentrated near the ground
3. Temperature droping: night time and/or cold front passage

is also known as ground fog. All fog is exactly the same as a cloud except a cloud forms hundreds or thousands of feet above the ground where as ground fog is touching the ground
think of the air as similar to a sponge, both can hold water, if too much water is added to a sponge the excess pours out, and if a sponge holding even small amounts of water is squeezed it will release some water. Cooling any air mass (large volume) makes it less able to hold water vapor (squeezing the sponge) water vapor collects on grass (dew) or dust (cloud/fog)
1. High humidity resulting in a temperature dew point spread of 4 degrees or less (best example: ground wet from recent rain fall orair near ground absorbes a water (a lot over a few hours)
2. Light or no wind( best example; winds usually are calmer at night, so moist air stays concentrated near ground (50'-300')instead of winds mixing air with dry air from above & around area )
3. A temperature drop of the air near the ground( best example: later in the evening if/when clear skies occur the suns heat in the surface of the ground is released upward as radiated heat into space the ground cools and cools the nearby air. Cool air can not hold as much water vapor as hot air, so the water vapor collects on tiny floating dust/smoke particles just like a cold can of any drink will be wet after a couple minutes out of the refigerator

Answer 2

The water vapor da yall some dummies who ant know dat