Bomb cyclone can bring blizzard conditions to parts of the UK
By
Adam Douty, AccuWeather senior meteorologist
Updated Jan 21, 2021 11:49 AM EDT
While Ice and Snow World and the Snow Sculpture Exhibition, two of the most famous festival sites, are open, all mass gatherings have been cancelled.
Several far-reaching storms impacting northern and western Europe this week will bring widespread rain, wind and snow. As the worst of the storm hits the United Kingdom, it can strengthen rapidly into a 'bomb cyclone', unleashing a blizzard across portions of England and Scotland.
“There will be a total of three storms to impact the region through Thursday,” said AccuWeather Meteorologist Tyler Roys.
“The first storm was named Storm Christoph and moved across the British Isles Tuesday and Tuesday night with heavy rain. Through Wednesday, this brought snow to southern Norway, central Sweden and Finland, as well as a period of snow that transitioned over to rain across the Baltic States and southern Sweden,” Roys explained.
Much of Germany were milder and dry on Wednesday allowing any snow that accumulated to begin melting. Dry weather returned across Poland in a west-to-east fashion during the day on Wednesday.
Roys said, “The second storm, which has been named Storm Geatan by the Portuguese Weather Service, will move across the British Isles on Wednesday and into the North Sea by Thursday.”
Storm Geatan will bring its greatest impacts to the British Isles from into Thursday as it rapidly strengthens.
Roys added, "Storm Geatan can strengthen rapidly enough that it is expected to become a bomb cyclone."
When the barometric pressure of a storm falls at least 0.71 of an inch (24 millibars) in 24 hours, it is classified as a bomb cyclone. The process is called bombogenesis.
While precipitation in many areas across the United Kingdom began as rain on Monday night and Tuesday, Roys explains, “As the bomb cyclone approaches Norway and intensifies, colder air will wrap around the storm causing rain to transition to snow across the higher elevations of northern England and Scotland. This can produce blizzard conditions from Wednesday night to Thursday afternoon.”
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The criteria for a blizzard as defined by the UK Met Office is “Moderate or heavy falling snow (either continuous or in the form of frequent showers) with wind speeds of 30 mph or more and a reasonably extensive snow cover reducing visibility to 200 meters or less.”
The heaviest snow will be reserved for the Scottish Highlands as well as the hills of southern Scotland and northern England, where 8-15 cm (3-6 inches) can fall in many areas, though even greater snowfall may be seen across the highest terrain. However, snow accumulations alone are not expected to bring the most significant impacts.
As the storm strengthens across the North Sea and winds increase, blowing snow can greatly reduce visibility and cause severe drifting. This may render some roads impassable into Thursday.
The A68 from Newcastle upon Tyne to Edinburgh as well as the A9 through Scotland could have delays due to slippery conditions. Some of the greatest major travel impacts will be reserved for roads such as the A93 that travel across mountainous areas.
The air will be cold enough to allow for settling snow even in lower elevations like Edinburgh, where 5-10 cm (2-4 inches) can accumulate into Thursday morning.
As the storm spreads moisture into Scandinavia, heavy snow will fall across much of southern and central Norway into central Sweden. The most significant accumulation will be just inland across southern Norway, where 30-60 cm (12-24 inches) can accumulate through the course of the week.
In addition to the snow, heavy rain in southern and western parts of the United Kingdom and can spark flooding. Wales and northwestern England are most likely to get rain heavy enough to produce flooding. Heavy rain is also possible across far northwestern Spain. Rain amounts in these areas can reach 50-100 mm (2-4 inches) from Monday night into Thursday with an AccuWeather Local StormMax™ of 200 mm (8 inches).
Roys added, “A third and final storm will move out of the Atlantic Ocean eastward through the Bay of Biscay into western France on Thursday. This will bring heavy rain to northwestern Iberia and western and central France, along with damaging winds to the western France.”
This storm is expected to be fast moving and largely be a wind producer with gusts reaching upwards of 100 km/h (about 60 mph) in northwestern Spain as well as western and northern France. An AccuWeather Local StormMax™ wind gust of 120 km/h (75 mph) is expected and most likely in western France.
These winds can be strong enough to knock out power to some areas and down some tree branches.
The three storms are expected to weaken as they push into eastern Europe as the week progresses. While they can bring areas of rain and snow, impacts are expected to remain much less than compared to northern and western Europe.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
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News / Weather Forecasts
Bomb cyclone can bring blizzard conditions to parts of the UK
By Adam Douty, AccuWeather senior meteorologist
Updated Jan 21, 2021 11:49 AM EDT
While Ice and Snow World and the Snow Sculpture Exhibition, two of the most famous festival sites, are open, all mass gatherings have been cancelled.
Several far-reaching storms impacting northern and western Europe this week will bring widespread rain, wind and snow. As the worst of the storm hits the United Kingdom, it can strengthen rapidly into a 'bomb cyclone', unleashing a blizzard across portions of England and Scotland.
“There will be a total of three storms to impact the region through Thursday,” said AccuWeather Meteorologist Tyler Roys.
“The first storm was named Storm Christoph and moved across the British Isles Tuesday and Tuesday night with heavy rain. Through Wednesday, this brought snow to southern Norway, central Sweden and Finland, as well as a period of snow that transitioned over to rain across the Baltic States and southern Sweden,” Roys explained.
Much of Germany were milder and dry on Wednesday allowing any snow that accumulated to begin melting. Dry weather returned across Poland in a west-to-east fashion during the day on Wednesday.
Roys said, “The second storm, which has been named Storm Geatan by the Portuguese Weather Service, will move across the British Isles on Wednesday and into the North Sea by Thursday.”
Storm Geatan will bring its greatest impacts to the British Isles from into Thursday as it rapidly strengthens.
Roys added, "Storm Geatan can strengthen rapidly enough that it is expected to become a bomb cyclone."
When the barometric pressure of a storm falls at least 0.71 of an inch (24 millibars) in 24 hours, it is classified as a bomb cyclone. The process is called bombogenesis.
While precipitation in many areas across the United Kingdom began as rain on Monday night and Tuesday, Roys explains, “As the bomb cyclone approaches Norway and intensifies, colder air will wrap around the storm causing rain to transition to snow across the higher elevations of northern England and Scotland. This can produce blizzard conditions from Wednesday night to Thursday afternoon.”
CLICK HERE FOR THE FREE ACCUWEATHER APP
The criteria for a blizzard as defined by the UK Met Office is “Moderate or heavy falling snow (either continuous or in the form of frequent showers) with wind speeds of 30 mph or more and a reasonably extensive snow cover reducing visibility to 200 meters or less.”
The heaviest snow will be reserved for the Scottish Highlands as well as the hills of southern Scotland and northern England, where 8-15 cm (3-6 inches) can fall in many areas, though even greater snowfall may be seen across the highest terrain. However, snow accumulations alone are not expected to bring the most significant impacts.
As the storm strengthens across the North Sea and winds increase, blowing snow can greatly reduce visibility and cause severe drifting. This may render some roads impassable into Thursday.
The A68 from Newcastle upon Tyne to Edinburgh as well as the A9 through Scotland could have delays due to slippery conditions. Some of the greatest major travel impacts will be reserved for roads such as the A93 that travel across mountainous areas.
The air will be cold enough to allow for settling snow even in lower elevations like Edinburgh, where 5-10 cm (2-4 inches) can accumulate into Thursday morning.
As the storm spreads moisture into Scandinavia, heavy snow will fall across much of southern and central Norway into central Sweden. The most significant accumulation will be just inland across southern Norway, where 30-60 cm (12-24 inches) can accumulate through the course of the week.
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In addition to the snow, heavy rain in southern and western parts of the United Kingdom and can spark flooding. Wales and northwestern England are most likely to get rain heavy enough to produce flooding. Heavy rain is also possible across far northwestern Spain. Rain amounts in these areas can reach 50-100 mm (2-4 inches) from Monday night into Thursday with an AccuWeather Local StormMax™ of 200 mm (8 inches).
Roys added, “A third and final storm will move out of the Atlantic Ocean eastward through the Bay of Biscay into western France on Thursday. This will bring heavy rain to northwestern Iberia and western and central France, along with damaging winds to the western France.”
This storm is expected to be fast moving and largely be a wind producer with gusts reaching upwards of 100 km/h (about 60 mph) in northwestern Spain as well as western and northern France. An AccuWeather Local StormMax™ wind gust of 120 km/h (75 mph) is expected and most likely in western France.
These winds can be strong enough to knock out power to some areas and down some tree branches.
The three storms are expected to weaken as they push into eastern Europe as the week progresses. While they can bring areas of rain and snow, impacts are expected to remain much less than compared to northern and western Europe.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo