Ban The Bomb

Weather enthusiasts are up in arms over the misuse of the term “weather bomb” in relation to some of the stormy weather that has hit New Zealand in recent weeks.

Of the three low pressure systems that have grazed our shores during the past ten days or so, only one technically qualified as a “weather bomb.”

The term is badly chosen as it looks and sounds like colloquial English and is better suited to being one of those vividly descriptive terms like Jim Hickey’s “polar rodent” or the late Augie Auer’s “blue dome days” etc. No wonder it has been mis-used to describe the violent weather that has recently hit various parts of New Zealand leaving destruction as if a bomb had gone off nearby.

The trusty Oxford dictionary describes a bomb as, “a container with explosive, incendiary material, smoke, or gas etc., designed to explode on impact or by means of a time-mechanism or remote-control device.” Hardly a suitable noun to be applied to a weather feature which is neither designed by man and nor under our control.

Apparently, a weather bomb is defined as an intense low-pressure weather system with a central pressure that drops by 24 hPa (hectopascals) or more in 24 hours. These are severe wintertime storms that bring destructive winds and intense rain. Of the three low pressure systems that have brought flooding, thunderstorms, a tornado, strong winds and intense rain to New Zealand since July 25th, only one has technically qualified as a “weather bomb.”

What has complicated the situation in the public mind, is that the first low was fast-moving and wreaked havoc from Northland to Gisborne. The second system arrived hot on its heels and was very slow moving. The path of this system, which technically qualified as a weather bomb, allowed it to affect almost the entire country.

The third event was smaller but brought heavy rain to northern New Zealand, thunderstorms to western parts of the North Island, and dumped 25 mm on Tawa in a 12-hour period from 7:30 p.m. on Saturday August 2nd 2008. A spectacular thunderstorm around midnight last night also threw hail about and run-off from already soaked lawns was high.

Those who were woken by the noisy storm would have been justified in thinking they’d been visited by another “weather bomb” but the weather system didn’t technically qualify for the moniker.

In the minds of non-meteorological types, “weather bomb” probably means “big storm.” Perhaps New Zealand should extend its nuclear-free legislation to ban the weather bomb as well. Not only would the weather be nicer, but our weather commentary would be less confused.

However I fear that even our politicians, who have a passion for banning things in New Zealand, aren’t sufficiently omnipotent to ban the weather features known as weather bombs. We will have more success by herding our meteorologists into a locked room and only letting them out when they have dreamt up a more logical term to describe a low pressure system with a central pressure that drops by 24 hPa or more in 24 hours.

And if they don’t, we can always send Jim’s polar rodent into the room to stir them up.

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