Explained: Alicante Cloud Engulfs Beachside Hotels [Advection Fog]

Mick West

Administrator
Staff member
Interesting cloud, on first glance it looks a bit like smoke and dust from a collapsed building:



If you look closer it's not really as dense as it seems, it's actually quite wispy. The fog seems darker because there are dark buildings in the fog, and dark hills behind it.

It's actually just another example of foggy air from the ocean moving in and rising up over beachside hotels, forming more dense fog as it rises, like this example in Panama City, Florida,





The rising air cools slightly as it rises, and as the conditions are "just right" for fog formation, this make more fog form as the air rises. Technically it's a type of "advection fog" (advection means the movement of the air, so it's fog caused by the air movement).

http://www.hko.gov.hk/education/edu01met/wxphe/ele_water4seasons_e.htm



According to Dr Greg Forbes, of Weather.com, the phenomenon occurred as a result of warm, moist air forming 'just right' as it blew into the coastline, forming a low-lying fog that dissipates as the air cools with altitude.

Dr Forbes explained on the website: 'You see the clouds forming off shore, as the winds from south to north push them toward and then up over the high rises as the air rises and reaches its crest.

'And then sinks back down and lowers the relative humidity and the clouds dissipate.'

'The other thing that's happening is with friction, the air slows down as it just begins to move onshore,' Dr Forbes explained.

'That gives it a little extra convergence and an upward forcing of the air to rise. But it must be that relative humidity needing to be just right that... explains why we don't see this kind of a picture every day.'

Read more: http://www.dailymail.co.uk/news/art...uds-took-Florida-coastline.html#ixzz2yhjb3MYM
Content from External Source
The Daily Mail even covered this new story, with an essentially correct explanation:
http://www.dailymail.co.uk/travel/a...ulfing-Alicante-beach-prompts-fears-fire.html
It was explained as a phenomenon that occurs when the cold sea meets the warmer air from inland, causing a huge cloud to form.
Content from External Source
Here's another, less dramatic example:
http://zihuatanejo.net/blog/2012/04/11/day-of-the-strange-fog-in-ixtapa-zihuatanejo/



Another in china:
http://english.cntv.cn/20110610/104774.shtml



Here the fog seems to be caused by the rising of the air over the bridge:
http://epod.usra.edu/blog/2003/06/deception-pass.html


And similar fog in San Francisco, where fog is more common

And a cool video showing the SF fog in more detail, and how quickly it moves, like the "smoke" in the first video:
 
Last edited:
amzin nature, thanks the post i've not seen this before,,, on mountains yes not over beach front high rise.

from the utube comments:)
On Earth we called this "The Fog creeping in". I miss that place!
Content from External Source
 
And similar fog in San Francisco, where fog is more common


Those pictures of the fog over the beach hotels are amazing!

Not to nitpick but I dont think the fog in San Francisco is the same thing...I dont think its advection fog. I think its just standard ocean fog (if there is a difference). The picture shows it streaming up and over Alcatraz but what it doesnt show is that the fog is just a tendril pouring in the Golden Gate from the huge fog bank just offshore. Same thing with the pour-over on the coastal ridge. Thats just the afternoon push of coastal fog. I live about a mile from the Golden Gate and a coastal ridge and often the fog will appear to be pouring over the top - soon to envelop the other side- but dissipate continually as it crests the ridge. It will do this all day and them sometime in the night will finally win out and you will wake up to fog. (Another time I lived in a high hill in SF and we had what I termed "fog blizzards"- the fog would come roaring in with 20-30mph winds for several hours- pretty cold and miserable fro June- yet I could look out my window and see sunlight in the rest of the city...)

Depending on the conditions, sometimes the fog is just over water off shore, sometimes it slips in the gate enveloping the bridge (over even just under it) but still just sticking over water, sometimes its pours over the coastal hills- eventually spilling over the City and coastal areas, sometimes its has a high deck (2000ft) and moves over 30 miles inland. Its a main factor in the "micro climates". It can be 54 and foggy at the coast and 100 and sunny 30 miles inland.

wiki explains better than I can:

Under normal summertime conditions, a daily pattern of fog and low clouds occurs. Morning sun heats the ground which in turn heats the marine layer over the land areas. This creates convective turbulence within the marine layer as well as evaporation. The marine layer clears back toward the coast, usually by noon. By mid-afternoon, inland areas have heated sufficiently to decrease the air pressure and increase the onshore flow. By late afternoon, the wind increases and begins to cool the onshore marine layer, allowing the fog and low clouds offshore to progress inland without evaporating. Cloudiness streams in over the Bay and through the various gaps. How far the clouds can penetrate inland depends on the depth of the marine layer and the strength of the cooling winds. As night falls and inland areas cool down, the winds usually decrease, but the fog and clouds remain wherever they have blown in until the following morning when the cycle repeats.
Content from External Source
I have been in coastal NorCal for almost 20yrs and still find the fog fascinating.

GGFog.jpg SFfog.jpg
 
The SF fog may not be entirely advection fog, but it's certainly advecting :)

I included it because it was similar looking, and the video shows just how fast it can move. We have similar fog rolling in here in Venice occasionally (the marine layer). It can be lovely sunny day, then then two minutes later it's cloudy and freezing. Really confuses the tourists.
 
The SF fog may not be entirely advection fog, but it's certainly advecting :)

I included it because it was similar looking, and the video shows just how fast it can move. We have similar fog rolling in here in Venice occasionally (the marine layer). It can be lovely sunny day, then then two minutes later it's cloudy and freezing. Really confuses the tourists.


They say you can tell the tourists in SF because they are wearing shorts...and a brand new "San Francisco" sweatshirt :)
 
They say you can tell the tourists in SF because they are wearing shorts...and a brand new "San Francisco" sweatshirt :)

Hah, I think I've bought three Venice Beach sweatshirts unexpectedly in the last 20 years, and I live here.
 
They say you can tell the tourists in SF because they are wearing shorts...

Hang on a tick!!! I wear shorts (here in LA) year 'round! Even when I lived back East, in the DC area....(I had a next-door neighbor who teased me about it!).
 
The SF fog may not be entirely advection fog, but it's certainly advecting :)

I included it because it was similar looking, and the video shows just how fast it can move. We have similar fog rolling in here in Venice occasionally (the marine layer). It can be lovely sunny day, then then two minutes later it's cloudy and freezing. Really confuses the tourists.
The marine layer in S.F. isn't quite as bad as say the fog in the central valley is. Visibility can drop to your windshield in some places on a regular basis. Pacheco Pass comes to mind.
 
There's a beautiful little mountain just north of SF, called Mount Tamalpais...there's a small campground ("Pantoll")
near the top...I used to set up a little camp there and take my niece on the lovely stroll down to Stinson Beach.

Point being, sometimes, right in the middle of a gorgeous, sunny afternoon, a giant cloud will just envelope the mountain,
and you're instantly & shockingly in a dark, damp, chilly place.

Screen Shot 2014-04-13 at 11.31.30 AM.png
 
...and you're instantly & shockingly in a dark, damp, chilly place.

That is poetic in a way, and frankly, sounds delightful!!

(Maybe I'm just being morbid.....)

(The new episode of "Game of Thrones", Saeson...SEASON 4 comes on tonight. It's on my mind, I suppose....)
 
Best advice I can give to anyone planning a trip to San Francisco in the summer is, bring a jacket!

And the tenderloin is not a restaurant, you don't want to visit there!
 
Best advice I can give to anyone planning a trip to San Francisco in the summer is, bring a jacket!

And the tenderloin is not a restaurant, you don't want to visit there!
But if you want to learn about the glorious people's revolution of Cuba you should visit Castro Street.
 
Tule fog.....oh man, that brings back memories....haven't heard that term in a long time.

Really, I appreciate that you just stimulated those memory engrams!! ;)

The "Ultimate Computer"....even in the 1960s, the danger was hinted at:
 
Interesting cloud, on first glance it looks a bit like smoke and dust from a collapsed building:



If you look closer it's not really as dense as it seems, it's actually quite wispy. The fog seems darker because there are dark buildings in the fog, and dark hills behind it.

It's actually just another example of foggy air from the ocean moving in and rising up over beachside hotels, forming more dense fog as it rises, like this example in Panama City, Florida,





The rising air cools slightly as it rises, and as the conditions are "just right" for fog formation, this make more fog form as the air rises. Technically it's a type of "advection fog" (advection means the movement of the air, so it's fog caused by the air movement).

http://www.hko.gov.hk/education/edu01met/wxphe/ele_water4seasons_e.htm



According to Dr Greg Forbes, of Weather.com, the phenomenon occurred as a result of warm, moist air forming 'just right' as it blew into the coastline, forming a low-lying fog that dissipates as the air cools with altitude.

Dr Forbes explained on the website: 'You see the clouds forming off shore, as the winds from south to north push them toward and then up over the high rises as the air rises and reaches its crest.

'And then sinks back down and lowers the relative humidity and the clouds dissipate.'

'The other thing that's happening is with friction, the air slows down as it just begins to move onshore,' Dr Forbes explained.

'That gives it a little extra convergence and an upward forcing of the air to rise. But it must be that relative humidity needing to be just right that... explains why we don't see this kind of a picture every day.'

Read more: http://www.dailymail.co.uk/news/art...uds-took-Florida-coastline.html#ixzz2yhjb3MYM
Content from External Source
The Daily Mail even covered this new story, with an essentially correct explanation:
http://www.dailymail.co.uk/travel/a...ulfing-Alicante-beach-prompts-fears-fire.html
It was explained as a phenomenon that occurs when the cold sea meets the warmer air from inland, causing a huge cloud to form.
Content from External Source
Here's another, less dramatic example:
http://zihuatanejo.net/blog/2012/04/11/day-of-the-strange-fog-in-ixtapa-zihuatanejo/



Another in china:
http://english.cntv.cn/20110610/104774.shtml



Here the fog seems to be caused by the rising of the air over the bridge:
http://epod.usra.edu/blog/2003/06/deception-pass.html


And similar fog in San Francisco, where fog is more common

And a cool video showing the SF fog in more detail, and how quickly it moves, like the "smoke" in the first video:


By the love of the mighty Aesir, that is beautiful!
 
I live on the North Sea coast so I'm quite familiar with the Haar or Sea Fret that we get. My other half is from the south coast though and it did freak her out a bit the first time she experienced it. :D
 
Back
Top