"Joe Egginton" wrote ...
snip
What would be recorded, if the scenario was:

Air Temp: -1c
Dew Point Temp: -0.5c
.... Before recording anything here, I'd be re-checking my calculations
with the slide rule! Dew point temperature should be same as or
_lower_ than air temperature, here you've got the dew point
temperature *higher* :-)


There's rime on a metal post, but no rime on a wooden fence. Would
that be recorded as freezing fog?

.... as long as the fog was depositing rime-ice, then it should be
entered as freezing fog (for SYNOP & other records); When I was
observing (professionally), the best object to keep an eye on (and one
of the easiest to monitor as it was usually close to the office) was
the cloud-searchlight alidade: this is the metal plate with a movable
pointer which you used to assess the angle of elevation of the cloud
'spot', then the angle is converted to cloud height. Sometimes (as at
Northolt for example) the office was close to the flight-line and you
could watch for riming on the starter trucks or extinguisher trolleys
etc.

Martin.

--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023