Storm Eunice warnings 'should not be taken lightly'

Prof Hannah Cloke, Professor of Hydrology, Department of Geography & Environmental Science and Department of Meteorology, University of Reading, said:

“The Met Office red and amber warnings for high winds on Friday should not be taken lightly.  Red means you need to act now because there is an imminent danger to life.  Everyone who lives or works in those areas should be battening down the hatches, literally in some cases, to prevent people from being killed and injured and to protect your homes and businesses.

“Let us be clear what this means.  Winds of 70mph will uproot trees, which can block roads and crush cars or buildings.  They can pick up roof tiles and hurl them around.  If you’re hit by one of those you will be seriously hurt or killed.  Wind that strong will sweep people and vehicles off streets, and topple electricity lines.  Don’t take any chances.  Stay inside.”

Dr Ambrogio Volonté, a storm scientist at the University of Reading, said:

“The conditions that have led to two named storms in three days over the UK are very strong jet stream winds several miles above the Atlantic, which help the genesis of winter storms.  Eunice, in particular, started its growth in a particularly favourable region for storm development, on the right side of the entrance of the strongest part of this jet stream – an area meteorologists call the ‘jet streak’.  Storm Dudley developed in another equally favourable region, at the left exit of the jet streak.

“Red warnings for winds are not unheard of but they are fairly rare.  Before Eunice we had storm Arwen in November 2021.  Before that, there was a red warning for wind in January 2016.  There is definitely a serious risk of strong and damaging winds.  People should not take chances with this storm, and should follow the latest advice issued by the Met Office warnings.

“The Met Office warnings for Eunice mention max gusts up to 90mph near coastal areas in south-west England and south Wales.  In the 1987 storm maximum recorded gusts were in the region of 110-120mph, so the intensity of Eunice is forecast to be lower, although the extensive red and amber warnings are entirely justified.

“The structure and shape of Eunice is similar to the 1987 storm.  In particular, Eunice is a “Shapiro-Keyser cyclone” (as opposed to the more common “Norwegian cyclone”).  In this type of storms, the cold front does not catch the warm front, but instead detaches from it, opening a fracture between the two fronts.  It is in that region that damaging winds can descend towards the ground (the “sting jet”).  It was the sting jet that caused the catastrophic damage associated with the ‘87 storm.

“Observing sting jets and evaluating their impacts is rather difficult, as they are localised and short-lived features, that descend towards the grounds but might not reach it, or might only reach the surface when the storm is still over the sea.  Whether we get a sting jet or not with storm Eunice, which as of today, Thursday, is a possibility but not a certainty, we will still get very severe winds which could cause some serious damage to property and put people’s lives in danger.

“These storms are both rapidly developing cyclones, also known as ‘bomb’ cyclones.  Due to the conditions in which they develop, they feature a remarkably steep drop in pressure, more than 24 millibar in just 24 hours.”

Dr Peter Inness, meteorologist at the University of Reading, said:

“Winter storms affecting the UK form in periods when there is a strong jet stream blowing across the Atlantic Ocean, with winds 7-10 km above the ground often well in excess of 150 miles per hour.  Currently the jet stream winds are close to 200 miles per hour at a height of 9 km above the ground in the eastern Atlantic.

“A strong jet stream like this can act like a production line for storms, generating a new storm every day or two.  There have been many occasions in the recent past when two or more damaging storms have passed across the UK and other parts of Europe in the space of a few days.

“Eunice looks like it may be able to produce a 'sting jet', a narrow, focused region of extremely strong winds embedded within the larger area of strong winds and lasting just a few hours.  Such events are quite rare but the 1987 'Great Storm' almost certainly produced a sting jet, and some of the more damaging wind storms since have also shown this pattern.  Scientists at the University of Reading have led the world on research into this phenomenon.

“Red warnings for wind in the UK are unusual.  A red warning was issued down the East Coast of Scotland and Northern England for Storm Arwen back in November, but two red warnings for wind in a single winter is very unusual.  Typically we might get one every 2 or 3 years.”

Prof Len Shaffrey, climate scientist at the University of Reading, said:

“North Atlantic storms often cluster together, so it’s not unusual to get strong storms one after the other.  We’ve seen lots of example of this in the past, for instance, in the winter of 2013/14 and the two extreme storms that hit northern France in December 1999.

“Climate model projections suggest that there will be a modest increase in north western European storminess over the coming decades due to climate change.  However, climate model projections of storminess are uncertain and we haven’t seen an increase in north western European storminess or extreme winds in weather records.”