On 16/01/2013 06:44, Wendy Tinley wrote:
Is the type of fog we are experiencing in the North Midlands radiation fog? Just been reading about fog and the current weather conditions.

There are two kinds of fog, radiation and advection. Radiation fog
require clear skies, near calm winds (to provide some mixing) and a
sufficiency of moisture.
Advection fog occurs when warm air moves over cold ground, so e.g. when
a warm front moves in over cold ground after a number of hard frosts.
This is a simplistic explanation, but will suffice.
It can be quite difficult to forecast - e.g. Gatwick is in a fog hollow
(brilliant for an airport!). When I did weather observing at Heathrow,
we had to watch for fog forming over the reservoirs and drifting over
the airport - when it might start to dissipate because of the heat
island effect of the centre.
Your fog would appear to be radiation.

Cheers

Malcolm