Why giant ice storm fooled the forecasters
Forecasters didn't predict the massive ice storm that downed thousands of towering firs and pines, snapped power lines and left nearly a quarter-million people without electricity last week.
Seattle Times staff reporters
• Have a power-outage kit that includes flashlights and batteries, glow-in-the-dark sticks, a lantern, matches, a wind-up clock, a portable radio, a Mylar blanket and a can opener.
• To avoid deadly carbon-monoxide poisoning, keep generators outdoors when they're running. Make sure the exhaust is not near a window or other opening to the home. Keep the exhaust and muffler away from combustible material.
• Never burn charcoal indoors. Charcoal produces toxic fumes that can kill quickly.
• Use hot water sparingly.
• Turn off most electrical devices, and unplug sensitive electrical equipment. Leave a light switched on, however, so you'll know when the power returns.
• Never handle or approach a downed power line.
• Dress in layers and cover your head. Close off unused rooms. Close drapes to prevent drafts.
• Use only space heaters designed for the indoors. Even those need to be adequately vented to avoid carbon-monoxide poisoning. Keep space heaters away from curtains and clothing. Always turn off the heaters before going to bed or leaving home.
• Get fresh air and get help right away if you feel sick or dizzy while using a generator or space heater. Fatigue, nausea or sleepiness are signs of carbon-monoxide poisoning.
Brad Colman didn't expect a history-making freeze before he stepped outside his home south of Issaquah at 4 a.m. Thursday and found his car encased in ice.
He, like thousands of Western Washington residents, awoke to a surprise — the region's worst ice storm in memory.
But there is one crucial distinction: Colman is chief meteorologist at the National Weather Service in Seattle.
"I saw it (the ice) and I thought, 'This is bad; this is really bad,' " Colman recalled. "I knew we had a big problem."
Colman's forecasters didn't predict the massive ice storm that downed thousands of towering firs and pines, snapped power lines and left nearly a quarter-million people without electricity. That wreaked havoc on a theater company, caused bank branches and businesses from Cupcake Royale to Starbucks to close quickly or delay opening and forced others to scramble, burn cash and strain customer goodwill.
"We usually like to be six hours ahead, so we can let customers know what's happening before they leave home for the airport," said Ben Minicucci, chief operating officer for Alaska Airlines.
Instead, Alaska and Horizon Air canceled 387 flights Thursday, many with little warning, after frozen daggers formed overnight on the bodies and wings of planes in Seattle.
The damage and disruptions would have happened anyway — the weather service, after all, doesn't control what falls from the heavens — but given the sophistication of modern instrumentation and the Northwest's vaunted new coastal radar, how did meteorologists not see it coming?
The reality, said experts inside and outside the weather service, is that forecasting remains maddeningly inexact, particularly here in the Northwest, especially when dealing with snow and ice. Predictions draw on thousands of data points from radar, satellites, observations, weather instruments on commercial airline flights and computer models. But not even that can account for everything that influences storm development.
Small hiccups in data that feed the computer models can produce inaccurate projections, so experts every day adjust interpretations based on decades of experience. But with ice storms in Washington so rare, there is no past pattern with which to compare results. The last ice storm this significant occurred in 1996.
In fact, 12 hours before Thursday's crush of freezing rain hammered the Eastside, no one had foreseen it: not the National Weather Service, not local television meteorologists, not University of Washington professor and weather guru Cliff Mass.
"It played to our greatest weaknesses," Mass said. "To get snow or ice right, you have to get the right temperature structure vertically. But you also have to get the rain and the intensity of rain right. The models, almost all of them, kept precipitation to the south. It wasn't really spreading things up north, and when it did, it was warming them up enough to be rain."
Peter Neilley, senior vice president of global forecasting for The Weather Channel Companies, agreed. The Weather Channel Companies contracts with carriers like Alaska Airlines for detailed predictive services using proprietary information.
"It was an extraordinarily complex and difficult forecast," he said. "Anytime you're dealing with a situation that's on the cusp of being one thing or another, in a place with complex terrain like Seattle, it's going to be tough."
And, while new coastal radar installed last fall can provide advance warning of incoming storms, it surveys an area of only a few hundred miles off the coast. Storm systems still may be 2,000 miles out to sea or not yet formed a day before they hit.
"The coastal radar is a big step forward, but we're talking about an additional couple of hours of warning — not 12 hours and certainly not 24 hours," said KING-TV chief meteorologist Jeff Renner.
It's not that no one predicted freezing rain. By late Wednesday evening Renner was suggesting some of it could hit the Puget Sound region overnight. The National Weather Service had been saying for days that some areas should expect light freezing rain. But the severity of what was in store was not yet clear to anyone.
By Wednesday night, however, the weather service thought something might be off.
"We were just starting to get a sense that things should have been winding down but they weren't," said weather-service meteorologist Dennis D'Amico. "We knew something wasn't quite right. It's like you've baked a cake and are about to put the frosting on top and serve it, and you notice that one of your layers is missing. Then you have to think, 'Is this a major change?' "
A graveyard shift of three at the weather service quickly and obsessively reassessed the data. By 3:30 a.m. this night crew issued a winter weather advisory. Two hours later, an ice-storm warning went out, triggering emergency broadcast alerts.
For the National Weather Service, it already had been an intense week. Initial calls for a major snow in Seattle were scaled back and moved from Tuesday to Wednesday. But that's how the system is supposed to work — information gets refined over time as events get closer.
"I look at that as a great success," Mass said, and Renner agreed.
The National Weather Service can be slower than Mass to alter its early projections. It wants even more confidence before making changes, for good reason.
"We don't like to flip-flop," said Colman, the chief meteorologist. "Our mandate from Congress is the protection of life and property. People look to us to make decisions: Should I go to work? Is it safe to do this? We know the public will use inconsistencies as a reason to dismiss forecasts" — even when a forecast could save lives.
Certainly, skepticism was growing in some quarters. By midweek, some restaurateurs and entrepreneurs already had seen traffic slow to a trickle as snow warnings sent people home despite a shining sun.
"They didn't want to be stuck in the three inches of snow we were supposed to get Tuesday that never came," said Cupcake Royale owner Jody Hall.
She figures her chain of five stores saw a 40 percent drop in sales, beginning with Tuesday's forecast and including canceled orders from the University of Washington and Metropolitan Markets when the storm finally hit.
"I kept wishing it would either get better or really, really dump, because I was right on the decision-making cusp (about closing)," said Jim Drohman, co-owner of the Café Presse and Le Pichet restaurants in Seattle.
Seattle's 5th Avenue Theatre was deep into preproduction for an upcoming run of "Oklahoma!" but delivery of two sets from separate trucking companies were rerouted, and changing forecasts and conditions made it impossible for the theater to fully plan the load-in.
And many businesses were surprised about having to close early Thursday, after forecasts had called for rain and warmer temperatures.
"We expected smooth sailing driving home, and it was a bit of an ice skate home," said Starbucks spokesman Jim Olson.
By late Wednesday, Alaska Airlines, which relies both on the National Weather Service and its forecasting contractors, was convinced the worst was over.
"We got all of the reports and the forecast was pretty much that we're out of it and should almost be dry by morning," Minicucci said. "We intended to operate on a full schedule."
But, at 4 a.m. — just as Colman was heading to his car — Minicucci fielded a call from his workers. Heavy freezing rain was sticking to planes all over Seattle-Tacoma International Airport. Soon, de-icing jobs that usually take an hour were taking closer to four. By the end of the day, 32,500 passengers, just on Alaska and Horizon, were affected.
Airlines understand weather better than most. They receive nuanced forecasts so they can activate contingency plans. They also are loathe to express anger over erroneous forecasts.
"We work with these guys every day, and for the most part, they do a pretty decent job," he said. "They help us with turbulence models and turbulence plots. You have to look at their performance as a whole, and it's very good. Unfortunately, when they miss, they miss bad.
"But we also don't want to get so upset that they get so conservative that you're canceling flights when there is no bad weather."
Meteorologists are still unraveling the reasons their forecasts missed such a heavy storm. They knew that when there is frigid air near the surface and warm air overriding it, their models tend to blend the two more quickly than happens in reality. In addition, the extent of precipitation that formed over the Pacific Ocean wasn't captured by their models.
"We know we'll be wrong sometimes," Colman said. "Our job is to get back on track as best we can, and we did that here, and pretty quickly."
Mass also pointed out that the language of forecasts that citizens have come to expect doesn't allow for the kind of nuance that certain predictions really demand.
"Sometimes we're really certain, sometimes we're not as certain, but we don't really have a way to let people know that," he said.
Staff reporters Sanjay Bhatt, Celina Kareiva and Dominic Gates contributed to this report. Craig Welch: 206-464-2093 or firstname.lastname@example.org. On Twitter @craigawelch.