A hurricane may lose its name, its structure and even its place on National Hurricane Center tracking maps. None of that is a guarantee the storm’s meteorological energy won’t keep making mischief.
While still dangerous storm remnants—let’s call them zombie storms—are more common in the North Atlantic, a rarer Pacific example of this is occurring as former Hurricane Ana lends its strength to a system that’s forecast to lash the coast from British Columbia to Washington with high winds and heavy rain. Ana swept past Hawaii earlier this month, dropping as much as 11.7 inches of rain on Keaumo before taking a long, C-shaped curve to the north and east. Its moisture and energy merged into a low-pressure system in the Pacific Northwest.
The result threatened to snap limbs off trees, triggering power outages earlier this week. Environment Canada also predicted about 2.9 inches of rain to Vancouver.
A wind advisory was put up along much of Washington’s coast, where gusts as high as 55 miles per hour were possible, the U.S. National Weather Service said.
Hurricanes that form in the eastern Pacific and then make the loop back into North America aren’t common, said Jeff Masters, co-founder of Weather Underground in Ann Arbor, Mich. However, British Columbia can find itself in the path of zombies from further west.
“Once or twice a year, remnants of West Pacific typhoons can travel across the ocean, undergo extratropical transition and impact British Columbia as significant extratropical cyclones,” according to Environment Canada’s website. “The most famous of these storms was ex-Typhoon Freda, in 1962, which wreaked havoc along the west coast of North America.”
More than 50 people were killed in the U.S. and Canada, according to government reports.
Tropical systems get their power “from the release of energy due to cloud/rain formation from the warm, moist air of the tropics,” according to the U.S. Hurricane Research Division. The strongest winds are near the Earth’s surface, and air temperature across the entire storm is pretty uniform. While those tropical characteristics of Ana have been blown away, it’s adding fuel to headaches along the Pacific Coast.
Europe has had its share of trouble from Atlantic hurricanes this year. The remnants of Bertha reached Europe in August, and earlier this month Gonzalo’s leftovers did the same.
Masters said it’s more common for storms to linger in the Atlantic because the waters of the central Pacific tend to be colder and unable to sustain tropical systems as they make the big swing from Hawaii back to North America.
In the Atlantic, the Gulf Stream, which brings warmer water north into that basin, can provide enough energy for storms to hang together a little better before making the short trip to Europe.