Wicked storm may lash United Kingdom around Christmas Eve

Earth visualization of GFS model shows deep vortex just west of Scotland Christmas Eve, with roaring jet stream wrapping around it (Earth)

Earth visualization of GFS model shows deep vortex just west of Scotland Christmas Eve, with roaring jet stream wrapping around it (Earth)

Computer models are simulating a fierce tempest sweeping by the northern United Kingdom Monday into Christmas Eve.

The minimum pressures forecast by these models are characteristic of strong category 4 or low-end 5 hurricanes.

The lower the pressure, the more intense the storm. The European model (top, below) forecasts the storm – projected to be near the northwest coast of Scotland at 6 a.m. local time on December 24 - to boast an astonishingly low pressure of 929 mb. The GFS model (bottom below) prediction is only modestly higher at 934 mb.

European model simulation pressures and low levels winds in UK storm Christmas Eve (WeatherBell.com)

European model simulation pressures and low levels winds in UK storm Christmas Eve (WeatherBell.com)

GFS model simulation pressures and low levels winds in UK storm Christmas Eve (WeatherBell.com)

GFS model simulation pressures and low levels winds in UK storm Christmas Eve (WeatherBell.com)

Although the storm’s pressure may match that of a strong hurricane, its winds will not be as potent.  The wind fields in high latitude storms are more spread out than their tightly-wound cousins in the tropics.

Still, this storm has the potential to be memorable.

“A low even in the 930s [mb] would be the deepest in my lifetime,” says meteorologist Mark Vogan, a specialist on weather in the UK.  “Given current track, [I] think much of the UK sees gales but the worst will be largely in NW Scotland.”

Ryan Maue, meteorologist at WeatherBell Analytics, says explosively deepening storms reaching this intensity (pressures lower than 940 mb) occur about every other year in this region but the extreme tail of sub-930 and sub-920 mb storms is populated by many fewer.

“Anytime pressures go below 930 or 940 mb,  you have a lot of wind that can affect land and generate huge swell, waves,” Maue says.

AccuWeather’s Jesse Ferrell, who has been following this threat for several days, warns:

…wind gusts can be expected over 50 knots (58 mph or 93 km/hr) in much of the U.K. between now and Christmas Day, with gusts over 60 knots [near 70 mph] being the worst, according to these two forecast models [the European and GFS].

The specifics of the storm impacts will depend on its exact track.  If it’s farther south than current model projections, the effects will be more severe whereas a more northerly track might deliver just a glancing blow to UK’s northwest coast.

Various sources say the lowest pressure ever measured in the United Kingdom is 925.6 mb at Ochtertyre, Scotland from January 26, 1884. The minimum pressure from this 2013 storm probably stays safely above that benchmark unless it jogs southward.

The vigorous storm will be fueled by a powerhouse jet stream, screaming across the Atlantic at over 230 miles per hour.

The Christmas Eve storm is the last in a series of storms pounding the UK, energized by this roaring jet.  Winds up to 90 mph battered parts of the British Isles Wednesday. More storminess is expected today and Saturday, AccuWeather reports.

Watch the UK Met Office’s round-up of the weather through the Christmas holiday, below:

Related reading: 930MB LOW TO IMPACT UK? HOW DOES THIS COMPARE TO HISTORY? SNOW XMAS DAY? (Mark Vogan)

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