It’s all very well having the latest forecast from the radio, but sometimes a weather system winds up more than expected, as we all well know. Unless you’ve a barograph or one of the magic electronic equivalents, it pays to log the barometer every hour or so when trouble looks like brewing. Without being too pedantic about accuracy, if it falls at 8 millibars in three hours you’re almost certainly in for a full Force 8. Five millibars in the same time, and you’ll soon be reefing down. Force 6 will be with you by the time the kettle boils. Sadly, the same applies to a rising glass, although the blow may not be with you for quite so long.