Bananaskiner,
Close on the minima's, I believe for congested area by night 600' 5km viz, reduced to 2km with CAA exemption, 500' msd withing 1km. Therefore the only cause for concern would be the viz on the aforementioned metar. Not forgetting the small detail of the Pennines, Fohn effect, etc. If the author of this thread was so interested in the weather over Sheffield why didnt he get the TAF/Metar from Doncaster (EGCN) which would have given him more accurate information???? Just a small point i thought i would raise.