Forecasting Everest

Apologies to Bob Dylan, but if you’re climbing Mount Everest you do, actually, need a weatherman to know which way the wind blows.

At 29,029 feet, that wind is the jet stream, and for a lot of teams on Everest, the weatherman is Michael Fagin, a Seattle-based climber who runs a forecasting service called Everest Weather. He’s never been to Nepal, but from his station in Washington he averages international weather models, monitors the movement of the jet stream, and traces storms coming north from the Bay of Bengal.

Fagin is one of the only people who forecasts specifically for Everest. His main competition is a Swiss company called Meteotest. Together, they’re the guideline for climbers trying to figure out the tenuous weather windows on the mountain, and decide when to make their summit push.

Fagin, who is working with six teams this season, is a little slow to talk about his forecasting background, because it’s pretty untraditional. He doesn’t have a degree in meteorology—he worked in marketing until he was 50—but he became fascinated with mountain weather when he started climbing in the Cascades with the Seattle Mountaineers. He convinced a University of Washington professor to be his mentor and sat in on the classes that he though were necessary. Then he dorked out, ordering faxed copies of weather forecasts and shadowing local meteorologists. In 2003 he sent a free sample forecast to a few of the Everest climbing parties and it was so accurate that the next year some of them asked him to do it again. “It was an unknown commodity at that point,” he says.

Meteotest had started making forecasts a few years before, in the wake of the deadly 1996 storm, but before Meteotest, and then Fagin, started making Everest-specific forecasts, climbers made their bids for the summit based on long-range forecasts and luck, guessing at when they thought the weather would be good. Teams usually need a four-day weather window to move from Base Camp to the peak, and Fagin says that even with every bit of technology at his fingertips, he can only confidently build a forecast for three to five days.

It’s tricky to forecast for Everest: storms move fast, the mountain is at the mercy of the highly variable jet stream, and there’s nothing that gives accurate readings from the summit. “There’s no weather station up there, so it’s all conjecture,” Fagin says. That’s why remote forecasters can put together forecasts that are just as accurate, if not more so, than local forecasters, although Fagin takes into account feedback from his teams on the ground. “If my radar says it’s clear, and my teams tell me it’s snowing at Base Camp, that means something,” he says.

Wind and snowfall are the limiting weather factors. Winds on the peak can easily reach 125 mph, and storms can reduce visibility to nothing, that why May is prime climbing season. It’s when temperatures, winds, and storms all tend to be moderate. The jet stream moves off in the summer, but precipitation tends to be higher after monsoon season starts in June.

The availability and accuracy of weather models has changed a lot in the last 10 years. Fagin says that precipitation models haven’t changed but they have become much more accurate at predicting the movement of the jet stream.

A lot of weather models are in the public domain—anyone can go on the Global Forecast System website and looks at the models. The hard part is using them to make accurate predictions. Add that to the increased Internet access at Base Camp and some of the teams are trying to cobble together their own forecasts, often with dismal results. “I’ve heard from my teams that some of the smaller teams who don’t have the resources for the weather forecasts, will just follow the bigger groups when they make their summit push,” Fagin says.

Fagin’s relationships with the climbing groups who pay for his service vary. He says some teams will buy a single forecast off of him, but usually he’s locked in with a team for their entire trip.  He’ll send forecasts every other day as they trek to Base Camp, then update them daily while they’re thinking about summiting. He says he’s in touch a lot, especially if the weather changes. “My forecast is just one piece of the information,” he says. “The weather window might be perfect, but if their group needs another day of rest, they have to consider that. They have their own realities to deal with.” He charges $100 for a single forecast, and around $1000 for a whole expedition. Meteotest forecasts run $2,000 for a trip.

He thinks he’s been able to be accurate over the years because he’s detail oriented and because he’s constantly tweaking his forecasts. “The trick is to never get locked into your forecast,” Fagin says. “If Monday you said there was going to be no jet stream, on Tuesday you’ve got to be willing to retrench. Things change really fast up there.”