A meteorological phenomenon that has been dubbed a "weather bomb" looks likely to reach London by Friday, according to the Met Office's chief forecaster.
But what is it? And how bad will things get?
A weather bomb is an aggressive pattern of weather in which the central pressure inside a frontal depressions falls at a very rapid rate. The meteorologists describe it as “an intense low pressure system with a central pressure that falls 24 millibars in a 24-hour period.”
A more detailed description has it as being "directly linked to the meteorological phenomena known as rapid or explosive cyclogenesis".
This is where dry air from the stratosphere flows into an area of low pressure. This causes air within the depression to rise very quickly and increases its rotation, which in turn deepens the pressure and creates a more vigorous storm.
Here is what it looks like, courtesy of the Met Office:
Where is the weather bomb at the moment?
Currently it is battering the North East of the UK. In Argyll, the Met Office has recorded wind speeds of 77mph. Further south, in Gwynedd, the wind speeds have reached 67mph.
The Met Office has amber (“be prepared”) warnings for the North East of Scotland and tip of Northern Ireland and yellow (“be aware”) warnings as far south as Yorkshire and Wales.
Come Friday though, that will flip and London, the South East, South West and Midlands will receive the “be aware” level warning.
The chief forecaster is predicting that gusts in excess of 50mph could develop in the south of the UK, with wind speeds reaching 60-70mph likely to develop along Irish Sea and English Channel coasts. Heavy rain is also expected.
Here is what the Met is saying:
There is the potential for gales, or local severe gales, to develop across much of England and Wales during the first half of Friday, before easing by early afternoon. A band of heavy rain will accompany the low pressure system, this pushing quickly east through the day.
The public should be aware of the risk of disruption to travel and perhaps power supplies.
It adds: “This is a complex development and details may yet change. Therefore this alert is likely to be updated in the coming days as confidence grows in track and timing of this system.
Either way, it might be time to get your wellies on...