Predicting the weather is usually a thankless task. When the forecasts prove right, no one ever says thank you. But when they are wrong, government weathermen inevitably have to - so to say - weather public scorn. Complaining about inaccurate forecasts is a pastime for many people, but their criticism is particularly severe when it comes to a questionable call on the hoisting of a typhoon signal. Certainly, there have been times when the whole city has been shut down by a No8 typhoon signal but the weather has been uneventful.
The reality is that no storm warning system is perfect. The best that it can aim to achieve is to convey the right sense of danger and alertness so people will take necessary precautions. The latest move by the Observatory to fine-tune its tropical cyclone classification will give the public a better sense of the severity of a typhoon. Under the current system, a typhoon is a typhoon. In the revamped version, the more intense ones will be further described as either severe or super - the greater the wind speed, the more dramatic their description.
A super typhoon will not automatically warrant a No10 signal (last hoisted in 1999 for Typhoon York). Such a storm may be too far away from Hong Kong to pose a danger. But if a typhoon is closing in and a high typhoon signal has been hoisted, the new system should help people be better prepared. At the very least, calling a typhoon severe or super should jolt people out of complacency, which is a danger in a developed city like ours.
Nowadays, typhoons rarely inflict deadly damage as they once did. Our buildings and infrastructure are much more robust and our hillsides are no longer dotted with squatter huts. Sometimes, injury or death has resulted from the unwise actions of victims, however. For example, a swimmer died last summer when Typhoon Nuri hit Hong Kong, prompting the first No9 signal in five years. There are now groups of diehard water sports enthusiasts who deliberately take advantage of being able to leave work and head straight to the beaches during typhoons. The extreme conditions add excitement to their sport but quite a few have run into trouble, even if the results have not been as tragic as the drowned swimmer. The Observatory cannot stop people being foolhardy - all it can do is to make them aware of adverse conditions ahead.
In recent times, the Observatory has made technical improvements to its typhoon warning system. Instead of relying on measures taken only in Victoria Harbour, a network of sensors has been running across Hong Kong since 2007 to measure the wind speeds of tropical cyclones more accurately. In future, the Observatory will also send mobile-phone messages to people in sea-level Tai O and to relevant government staff to warn them about wind surges during a typhoon, which can cause flooding. This is a good start, but it should aim to offer such warnings to people in other places likely to be affected so that they can take better precautions and make informed decisions about whether to stay at work or school, or go home.