All good comments - thanks!
I will freely admit that icing is something which I don't know very much about. The reason for this, I think, is that I mainly fly aircraft with no de-icing, so I tend to be very conservative and stay on the ground if I feel there's a chance of icing. (Ironically, in all the time I've spent in IMC in de-iced aircraft - which isn't all that much - I've never once encountered any ice.) And since the best way of learning about something is to experience it, that means I've still got a lot to learn about ice.
A couple of posts on this thread have raised points which I'm interested in learning more about. Dr Eckener said:
It doesn't tend to work like that with fronts. The warm air behind is warm and the cold air in front is cold. If you are in the cold sector the freezing level will be as per the cold sector
Indeed, that fits in with my observations of what actually happened. But how does it fit in with a temperature of +3 degrees? This air temperature suggested to me a freezing level of between that quoted for before the front and that quoted for after the front, which seemed to fit in with the front being overhead..... which seemed quite logical at the time, but was obviously wrong.
And HWD picked up on a quote of mine, where I said:
Then we reviewed the actual weather. The temperature was +3, the dewpoint +2. I interpreted that to mean that the temperature at the cloudbase would be around about +2 degrees
Whatever the dewpoint is, if you take a parcel of air from the surface, and reduce the temperature of that air to the dewpoint, it will become fully saturated and start forming clouds. So what I have done (and it seems to have worked for me in the past) is reversed this, and said that, at the base of the clouds, the temperature and the dewpoint must be equal - or, to put it another way, the temperature at the base of the clouds is equal to the dewpoint as given on the ATIS. As I say, this has worked in the past (but maybe it's not actually correct?) It may well even have been correct yesterday - I don't know because we were never as high as the base of the clouds. But there was certainly a sub-zero layer below that - and what I don't quite understand is why no clouds formed in this sub-zero layer despite it being below the dewpoint.
There is always so much more to learn in this game......
(And just to lighten the tone a bit, while we're on the subject of how much there is to learn about the general subject of met, one of my colleagues, who is also a licensed met observer, has his own method of forecasting the weather. He reckons that whatever the weather is doing today, it will do the same tomorrow. He admits that this doesn't work all the time - but he reckons it's at least as reliable as the forecasts from the Met Office!)
FFF
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