This week we had a dense fog bank roll in from the sea. It was just one of the many mixed weather conditions on the Isle of Lewis including thunder and lightning.
Thundery outbreaks will lead to patches of very moist air and some dense fog banks, of both radiation fog and advection fog. The sailor is usually more concerned with advection fog which is caused by relatively warm, moist air flowing over a colder surface.
"Fog, mist and cloud are all formed when
air cools to its dew point (the term is self explanatory). Water in the air may
condense onto a cold surface such as the ground, a house roof or on to small
particles in the air (known in the trade as condensation nuclei). At ground
level the "cloud" is called fog or mist depending upon the
visibility. At sea or for aircraft landing and taking off purposes, fog is
defined as when the visibility is 1000 metres or less. Mist is a visibility
between 1000 and 2000 metres. Normally, over land, forecasters use the word "fog"
when the visibility is 200 metres or less. This is because a car driver may be
fairly happy if he can see over 200 metres while the same is not true for an
aircraft pilot landing at Heathrow or the skipper of a boat in mid Channel,
particularly a small yacht." (mailasail.com)
Even a local was impressed enough to get his phone camera out!
And it rolled over the hills and went.
A grand sight .
ReplyDeleteI've learned a new word - advection! Up until now, fog and mist to me were just... fog and mist, although I've always liked them both, no matter their name. Now I know more. Thank you!
ReplyDeleteWow - what fog!
ReplyDeletePlease say hi to Gareth from us, xx
Exotically beautiful. I remember while living in Texas and working on the coast driving from my sunny back yard into the fog covering Galveston Island. It was always so strange and took the better part of the morning to burn off.
ReplyDeleteA pretty sight! We get foggy mornings here that are just drippy and dreary.
ReplyDeleteThese photos are fabulous! Even though they're still photos, you can practically see and feel the movement of the fog as it slips past. xoxox
ReplyDeleteGreat shots... I'm still trying to figure out what the local guy has on his head. A bird?
ReplyDeleteThe local guy - aka my nephew Gaz - has his sunglasses perched on his forehead.
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