You might be thinking it’s been quite a snowy end to 2017 wherever you live in the country, but spare a thought for those of us down here in the southwest who so far have yet to see a snowflake. In Cornwall none of the SYNOP stations have reported an air frost so far this Autumn, and even here in mid-Devon although we have had four air frosts, and only one of these was for a temperature lower than -0.2°C.
I’d like to do a similar thing with snow that I do with frost, by checking for the occurrences of snow in the present weather from the hourly SYNOP files. Not only would that mean opening thousands of hourly SYNOP files, but many of the AWS reports either don’t report a present weather, or if they do they’re not that reliable when it comes to the reporting of freezing precipitation. The same thing applies to the reporting of thunderstorms, I have yet to see an AWS report a thunderstorm, even though I know the more sophisticated Vaisala systems are capable of sensing them.