Fog - Latest Update

[simonjk]

Afternoon,

Monitoring the fog situation here at the WCS Weather Centre.

ENGLISH CHANNEL:
Seems that the worst of the fog through the Channel is now around 5 to 10 miles offshore of the southern England coast, and extends right across the Channel to the northern coasts of France.

Watch out this afternoon as sea breezes may bring that back on-shore.

We expect little change tomorrow.

IRISH SEA/BRISTOL CHANNEL:
A thick blanket of fog now from Cornwall, through most of the Bristol Channel, west and north wales, and off NW England. This is also very dense in places and is likely to get pull back onshore as sea breezes develop.
We expect little change tomorrow.


Hope that is useful to some of you.

Best wishes,
Simon


<hr width=100% size=1>Weather Consultancy Services Ltd
www.weatherweb.net & www.wcsmarine.com

 

[Dreamers]

Thanks very much, Simon, this is much appreciated...................


now I really have something to worry about!!!!!!!!!!!

Only kidding - thanks for the effort.

<hr width=100% size=1>

 

[max]

Thanks. Any views on saurtday and Sunday Channel central?

<hr width=100% size=1>

 

[tony_brighton]

Can you help with my understanding. The YM courses all witter on about fog being caused by warm wet air passing over the cold water. Looking at the buoy data for mid-channel its seems that we have warm air over warm water - so I'm not quite sure why the fog is there?

<hr width=100% size=1>

 

[qsiv]

Using data from Jersey (not quite a bouys mid channel), I would argue that the reason is that the ambient air temperature is currently 0.3 deg C below the dew point, and as a result the moisture in the (previously very hot) air is being condensed out as suspended water droplets. The dominant breeze for several days has been from the East, and this hot moist air has now met cooler maritime conditions.

<hr width=100% size=1>

 

[simonjk]

No problem with the fog posting, glad to be of help. I will try to put similar postings on here in future if it helps everyone?

Couple of questions there, firstly the reason for the fog. It's because we have warm air flowing off the Continent over a cooler sea. The air in close proximity to the sea cools and eventually condenses out. Cooler air a cannot hold as much water vapour as warm air. Therefore this condenses out and forms the fog we have now.

Something interesting to note as well about the fog this afternoon. The wind actually became more west to NW through the Channel. This in effect cut off the warm source air and as well as pushing the fog back SE, it also began to disperse.

The second question was about this weekend in the central Channel.

We are back to the fog question again I think. Looks E-ENE F3-F4 Saturday, perhaps increasing F4, but again with a risk of fog forming as warm air moves off the Continent. Similar on Sunday in an E-ENE F3-F4 with the fog patches risk.

Incidentally I do a free weekend forecast which is devlivered by email each Wednesday or Thursday. See www.wcsmarine.com for more details.

Any more questions are welcome.

Simon



<hr width=100% size=1>Weather Consultancy Services Ltd
www.weatherweb.net & www.wcsmarine.com