The fog is closing in

[Jon George]

Fog forms when the difference between air temperature and dew point is less than 2.5 °C or 4 °F.[5]

Fog begins to form when water vapour condenses into tiny liquid water droplets suspended in the air. Six examples of ways that water vapour is added to the air are by wind convergence into areas of upward motion; precipitation or virga falling from above; daytime heating evaporating water from the surface of oceans, water bodies, or wet land; transpiration from plants; cool or dry air moving over warmer water; and lifting air over mountains. Water vapour normally begins to condense on condensation nuclei such as dust, ice, and salt in order to form clouds. Fog, like its elevated cousin stratus, is a stable cloud deck which tends to form when a cool, stable air mass is trapped underneath a warm air mass.

Fog normally occurs at a relative humidity near 100%. This occurs from either added moisture in the air, or falling ambient air temperature. However, fog can form at lower humidities, and can sometimes fail to form with relative humidity at 100%. At 100% relative humidity, the air cannot hold additional moisture, thus, the air will become supersaturated if additional moisture is added.

And the difference between mist and fog is? ....

 

[glasgowcyclist]

And the difference between mist and fog is?

¯\_(ツ)_/¯

 

[Ming the Merciless]

And the difference between mist and fog is? ....

The distance you can see. Fog is basically thick mist

 

[hoopdriver]

And pea soup fog is basically thick fog...

 

[Tin Pot]

Your late to the party, two hours late in fact.

My cataracts start forming about four hours into the party/drinking.

 

[Ming the Merciless]

Watch out for the hounds

 

[Ming the Merciless]

Freezing fog when it condenses and freezes on the windscreen

 

[Drago]

Your late to the party, two hours late in fact.

Sorry, its my age. I've regressed to 1971 already.

 

[Ming the Merciless]

A good winter end of 1970

 

[steveindenmark]

Glasgowcyclist....have you lot found a weather explanation app I have not found yet? :0)

I cut my 50km planned route down to 30km. I am used to cycling in the cold but it got so cold and damp it was hard to pedal at a rate to keep warm. I have spent the last couple of hours defrosting my bone marrow. I am all ready for my 4.30am commute. It' all good practice for next years Transcontinental.

 

[andrew_s]

Contacts are better than glasses.

An STVZO front light, mounted fairly low, is best for seeing in the dark.

Back lights are the brighter the better. I'd go for a very bright steady, plus next brightest on flash.

As far as clothing is concerned, you want something that contrasts with white fog - black or red rather than yellow, and a solid colour is better than patterned.

 

[steveindenmark]

Bloody freezing

 

[andrew_s]

And the difference between mist and fog is? ....

It's mist if the visibility is between 1 km and 5 km.
It's fog if the visibility is below 1 km.
It's thick flog if the visibility is below 100 m.

(Used to work as an official met observer at station 88952)

 

[Drago]

He could have bought a car for £400.

 

[Racing roadkill]

Watch out for the zombie Lepers