The remnants of hurricane Ophelia struck Ireland earlier this week, bringing with it wind gusts that exceeded 50 miles per hour and heavy downpours. The storm left at least three dead and hundreds of thousands without power, reports BBC News.
The ex-hurricane brought another less dangerous—but eerie—effect: A red haze over much of the United Kingdom.
As BBC News reports, this crimson gauze was the result of the storm's strong winds, which not only pulled dust from the Sahara Desert but also charred debris from fires in Portugal and Spain. (At the same time, these winds are feeding the fires, resulting in one of Europe's worst fire seasons.)
Short, blue wavelengths are usually scattered in the atmosphere—an effect that gives the sky its iconic color. But the increased dust also increases the scattering of this light, so much so that the longer, red wavelengths could shine through.
Many Twitter users in London used the opportunity to make jokes comparing the city to several other iconic locations with red skies, including the desert planet in Blade Runner 2049 or Tatooine from Star Wars, writes Matt Novak for Gizmodo.
Beyond the strange coloring of the sky, however, there's another puzzle related to the storm: how did it end up in the British Isles? Hurricanes in the Northern Hemisphere do occasionally stray from their westward paths to head toward the ocean near Europe, writes University of Leeds meteorologist Alexander Roberts for The Conversation. However, this usually happens via a circuitous path, with the storms slowly turning northward in a giant clockwise circle along the East Coast of the U.S.
Hurricane Ophelia took a different path after forming in an unusually northern locale in the relatively cold waters west of Morocco. There, instead of westward-blowing trade winds that guide most hurricanes toward North America, Ophelia was under the influence of the jet stream, which quickly began pushing the storm northeast toward Europe.
The red sun today tail end of hurricane Ophelia dragging in dust from the Sahara#redsun #uk #hurricance #ophelia #sahara #captue #naturephotography #sun #sunscape #dorset #vanlife #dust #tree #sunscape #red #orange #amazing #StormHour pic.twitter.com/knk6MHpMy3— Tide Photography (@tide__photo) October 16, 2017
Normally, the North Atlantic would be relatively hostile waters for a hurricane, notes Maddie Stone of Earther. Hurricanes thrive on heat, typically requiring surface water temperatures of at least 80 degrees Fahrenheit—something not typically found that far north.
But as Jason Samenow of the Washington Post reports, strong southerly winds ahead of the storm brought unusually warm—but still not hot—temperatures of some 77 degrees Fahrenheit to the British Isles, allowing Ophelia to slowly grow in strength. Ophelia reached Category 3 status last Saturday—farther east than any other hurricane in recorded history, writes Samenow.
Ophelia weakened into a "post-tropical storm" before striking Ireland on Monday.
Editor's note Wednesday October 18, 2017: This article has been updated to show storm Ophelia had some of the worst impacts in Ireland.