The forecast today has a term I’ve never seen used:
Valley cloud. Fog patches dissipating this afternoon. High plus 5 except plus 1 areas of low cloud
In other words, the fog may lift but won’t clear completely everywhere and so it will stay cold in those areas. Great day for a trip over to the East Coast!
Update: I’ve modified the Freezing Level calculation a bit so that it only calculates it if the Cloud Base is above 900m(3000ft). Below that usually means it’s foggy and/or inversion effect and the calculation is no good anyway. Hopefully that doesn’t completely wipe out it’s usefulness, as we all know how often we have fog or Valley Cloud during the winter. 🙂
Update: I’ve just installed the “hardened” temp/humid sensor that I received from Davis. It’ll take it a little while to acclimatize completely but it seems to be operating fine, hopefully this is the last time I have to go up on the roof this winter.