UK weather: Ex-Tropical Storm Henri – all you need to know
Tuesday, September 15, 2015, 10:00 GMT -
Here meteorologist Simon Keeling tells you all you need to know about ex-tropical storm Henri.
RELATED: Met Office issues warning for heavy rain as remains of Henri brings spell of wet and gusty weather
Is this really a tropical storm?
No! What's approaching is a normal area of low pressure of the sort we see crossing the UK from the Atlantic every year. It’s called an ex-tropical storm because when it developed it ticked all the right boxes to be classified as being borne out of a tropical disturbance but now it has downgraded and is no longer as strong.
But isn't it the 'remains' of Henri?
Well, sort of. Some of the moisture within the low pressure area does have origins from Tropical Storm Henri. The mild air within the low pressure system again originates from Henri, and that means the low pressure system can hold lots of water. This in turn strengthens the cloud and rain. But the air has modified since it crossed the Atlantic ocean and it doesn’t have the same energy as a tropical storm.
So what's its history?
Henri developed in mid-Atlantic a couple of weeks ago. During the middle to later stages of last week it was a long way off the coast of the eastern USA. First named as a storm last Wednesday, it tracked north and was last identified as of tropical storm strength last Friday. Since then the low pressure system has crossed the Atlantic, gathering moisture and will eventually reach the UK on Wednesday and Thursday.
And what's next?
We'll get rain, some of it heavy into the southern UK on Wednesday. This passes north bringing strong winds with it. A contrast between cold air as the rain arrives and the winds turn to the northeast, but milder, humid air arriving in the south later in the day.
For your latest hourly weather forecast, search your city or postcode in the orange 'Find your Forecast' box on The Weather Network UK website. Or download our free app from Apple iTunes or Google Play to regularly keep up-to-date with the weather, including UV, pollen and air pollution data.Follow Jamil Hussein on Google+, Twitter