We've become used to saying 'yet another Atlantic storm'. But what constitutes a storm in your opinion?

Is any one of the following sufficient on its own, or would you define it as a combination? Sample figures given to argue over

• central pressure - below 960mb - or gradient pressure?


• area of pressure below 975mb covering at least 40000 km2


• wind gusts exceeding 80mph or 120km/h


• sustained winds of 40mph or 70 km/h for at least 2 hours


• rainfall of at least 30mm over at least 4 MetO regions


• speed of movement over the ground

or would you go for an index based on damage (likely to be) caused, in which case a storm when all trees in full leaf would rate more highly than one in late winter.

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Assuming this is with regards to the whole low pressure system, rather then just an active front/ thunderstorm.

Gust 70mph+,

Avergae sustained winds at least 50mph (for no less then 3 hours)

Rainfall is not so relevant, if I hear the phrase Atlantic storm I think of wind more then the rain.

My opinion is a biased one resulting from living on the south coast. Sustained winds of 55-60mph for hours and hours on end are not uncommon at thorney & Solent (official stations), or at any exposed location in Portsmouth during windy Atlantic/ channel storms. The local topography seems to allow a tunneling of the energy through Solent.

It's also based on where you live. Something that might be considered a ''storm' in London would be no more than a windy day in Stornoway, for example.

 

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