High winds on Mt Rainier: thoughts and experiences

In the thread about the 4 missing persons on Mount Rainier , some people asked for my standards on what wind speeds are too high to consider ascending Rainier. It's hard to give a definite number for what wind speed would cause me to not leave town (or change plans) on a trip to Muir or the Rainier summit -- but I'll give my personal rough planning guidelines later.

But first, how about an anecdote about my first experience with extreme high winds:

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[size=small](I just told this story to a couple of my friends a few days ago, so it's fresh in my mind, but please realize that 15 years have passed and memory is notoriously unreliable -- some facts were checked against my notes in a spreadsheet from back then.)[/size]

My first ever backcountry ski trip was solo up to Camp Muir on a beautiful sunny day in June 1996, carrying my alpine skis and boots on my pack. I bought an alpine touring setup in the fall of 1996, skied Muir again on a couple of sunny days in October and November 1996, and began the Mountaineers ski mountaineering course in January 1997.

My 4th trip to Camp Muir (and only my 6th backcountry ski trip ever) was on February 16, 1997. I was joined by Alex, my UW physics grad school classmate and a very experienced climber, mountaineer, and ski mountaineer -- numerous ascents and ski descents of Colorado 14ers, summits of Rainier, Shasta, several other California 14ers, plus Aconcagua, lots of big aid climbs in Yosemite, etc. Four of his friends joined us, 2 guys and 2 girls. We headed up from Paradise on Saturday the 15th, with a fine forecast of sunny skies and moderate temperatures for the weekend, unusually nice weather for February in the Northwest. We set up camp near the saddle north of Alta Vista around 6200 ft, and skied some short afternoon runs before dinner. We planned to ski to and from Muir the next day.

The next morning dawned clear and pleasant, not even very windy at our camp. But looking up the Mountain, we could see big plumes of snow blowing east off of Anvil Rock and the upper slopes, and huge lenticulars stacked above the summit and off to its east. We knew the winds would be very strong on the Muir Snowfield, but the other 3 guys were eager to go up anyway. I agreed to join them, while the 2 women wisely stayed down low and skied something else near camp.

It was mid-morning when we left after a leisurely breakfast. We took a minimum of gear, trying to go fast and light to minimize the time we'd be up there in the wind: a single pack between the four of us stuffed with some extra clothing for each of us, carried in turns by Alex and Jeff, the two strongest among us. As we skinned above Pan Point and neared Pebble Creek, the winds were screaming from the west and southwest, and I soon took back all of my extra clothing from the communal pack. At least I had high-quality, totally windproof 3-layer Gore-Tex jacket, pants, and gloves, with lots of fleece underneath -- but I owned no down jacket or synthetic puffy at the time.

Onward and upward we skinned, with clear skies overhead but eventually a near whiteout where we were traveling: a true ground blizzard, with intense blowing snow despite clear skies and no snowfall. Above 9200 ft, past Moon Rocks and then Anvil Rock, the winds became even worse. Every time there was a strong gust, we'd brace ourselves with our poles planted in front of us and legs angled in a slight V. To no avail -- at least 3-4 times, the strongest gusts simply flung me off my feet and I'd land on my side, several feet to the right of the skin track. Alex was also knocked down a few times, while the other two were just far enough ahead of us to be totally out of sight in the blowing maelstrom of snow.

I think the main reason that we kept going was that it was so clear and sunny overhead, whenever the winds would briefly drop enough to thin the ground blizzard so we could see upward. We also knew that there was an unlocked public shelter at Muir to get out of the winds. It was also quite warm for February, about 25 °F at 10000 ft, otherwise I would have frozen some extremities for sure.

It was with immense relief that I finally arrived at the Muir hut and scurried inside, thankful for the sudden shocking calm after enduring 2 hours of extreme winds. A much different place back then prior to its renovation a few years ago, it was dark and dingy, with yellow stalagmites of frozen urine in the corner from some previous occupants.

When I unzipped my Gore-Tex jacket in the hut, I discovered that fine spindrift had penetrated the interior, presumably through the hood opening and down my neck. This snow was packed solidly in a white layer all around my chest between the outer shell jacket and my next fleece layer. I told Alex that wow, those winds must have been over 60 mph, right? He laughed and assured me that the wind gusts that had knocked us off our feet were more like 80-100 mph. I have no reason to doubt his estimate.

Anyway, after warming up for a while, we headed back out into the blowing snow and somehow skied back down through the blizzard -- it was not nearly as memorable as the ascent. By the time we dropped down Pan Face, the winds were again only a breeze, and arriving back at our camp it was still not very windy at all.

In almost 15 years since that day, and over 550 days of backcountry skiing and ski mountaineering, I have never once experienced winds like those again -- almost entirely because I've decided to never climb up into such extreme high winds again. I've definitely been in 50-60 mph winds a few times since then (Shasta, especially on Shasta!) -- winds strong enough to make skinning or standing difficult, but not nearly strong enough to simply fling me off my feet like those crazy winds on the Muir Snowfield that day!

P.S. I have no recollection whether we checked the NWS Rainier forecast prior to this February 1997 trip, nor do I recall if that forecast even existed in the same format back then (including the 3-day table of wind speeds). And sorry, no photos from the trip (the lenticulars were spectacular), I did not own a camera at that time.

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Back to the main topic -- several important points about wind:

1) To get expected real wind speeds on a high isolated mountain like Rainier, take the forecast average free-air wind speed, multiply by 1.5 to get expected average wind speeds, and multiply by 2 to get expected gusts. So if the forecast says 30 mph at 10000 ft, assume 45 mph average at 10000 ft on the mountain with gusts to 60 mph. This is just a crude estimate, but it's a good cautious rule of thumb.

2) The force of the wind is proportional to the square of the wind speed, so increasing the speed by 40% doubles the force, and doubling the speed quadruples the force: compared to a 30 mph wind, a 42 mph wind is twice as strong, and a 60 mph wind is 4 times as strong. This comes from basic physics and is an exact expression, not a rule of thumb or estimate at all, it is simply that way! This is the force that the wind puts on you while trying to stand or move, and also the force it applies into lifting snow off the surface to create a ground blizzard.

3) Because the force goes as the square of the speed, the effects increase very suddenly as wind speeds rise: 30 mph winds are a minor irritant (although they will prevent snow from softening to corn), 40 mph winds are a huge annoyance (and potentially dangerous for frostbite if the air temp is under 25 °F), 50-60 mph winds are very hard to stand upright in, and 80-100 mph winds will just fling you off your feet and onto the ground.

4) I always look at wind speeds in the NWS Rainier recreational forecast first, and then double-check the forecast wind speeds using the UW model , specifically using the 12 km 700 mb and 500 mb "temp, winds, heights" plots. The 700 mb pressure surface is at about 10000 ft, and the 500 mb is at about 18000 ft, so you have to interpolate between the two to get expected winds at 14000 ft, which is roughly 580 mb. A conservative approach is just to assume the winds at 14000 ft are equal to those higher up at 500 mb.


By the way, I've carried a small handheld wind speed meter ( Omega Engineering HHF 22 , about $100, weight only 2 ounces) on all my trips for about a decade, which helped me to double-check my guesses of wind speed in the field. Now after many years of practice, my estimates are pretty good and I hardly ever need to use the wind meter. It's still fun to check wind and temperature on summits, though.

So anyway, my own standards:

In general, when planning Rainier summit attempts, I look for a wind forecast under 10 mph at the summit -- yes, really! But there are only a small number of such days (roughly less than 10-15) in a typical year on Rainier, and they mostly occur only during summer -- although such a day is currently forecast for this Thursday, winds NW 9 mph at the summit!. Any forecast up to 20 mph could be OK too, but less than ideal. Remember, you have to multiply those by 1.5 to 2 to get real expected winds on the mountain.

Forecast wind speeds above 20 mph will almost certainly be miserable for skiing off the top, since the snow won't soften as needed even if the freezing level is high enough. Forecasts to 30-40 mph could be OK for climbing on foot in warm summer weather, but I very rarely go up any high volcano without skis.

For going to Muir, I'm not nearly as picky, since there's just a lot less effort invested and the consequences of high winds are much lower when not going above 10000 ft. And also, if the snow stays hard frozen due to high wind, it's not that big a problem for skiing down from Muir, but hard frozen snow is dangerous and a severe hazard on all summit ski routes.

So I can accept a bit more forecast wind for Muir trips, I'll head up there with forecast winds up to about 30-35 mph if it's sunny and warm enough (freezing level 7-8000 feet or higher). I still prefer the forecast wind to be under 10 mph though -- there are a few dozen days per year with such winds at Muir. But I rarely ever head for Muir if the temps are expected to be below 15-20 °F, I'm just not very cold tolerant even when the winds are light. Obviously, many others (especially those of European or north Asian descent) have a much greater natural tolerance for cold temperatures than I do, and they could function easily in cold and winds that would incapacitate and endanger me.


[size=small](Edited to add links to the forecast and UW model.)[/size]

Thanks Amar , Great read and good advice!
I do know what you mean about Shasta. We were pinned down for 3 days above Brewer creek. Never made the summit.

Having been young and stupid once (now I'm middle aged and only sometimes stupid) I think we should take these opportunities to remind ourselves that Rainier is a bad place to be in a storm. My first ascent of Rainier (the Emmons Route in 1987) we were in white out conditions above 13K with a light breeze. Even through we were the only summit party that day we wanded the route well and managed to summit and return with no issues. My second ascent (14 years later) included an afternoon hunkered down at 13,600 in a summer snowstorm with ~50 mph winds. This experience was scary and (due to inadequate equipment) would have been life or limb threatening if the storm had continued another day or so. High winds made all the difference between those two days.

Based on this experience and a few others I have two simple rules:

1) Stay near or below treeline when even the mildest storms are predicted.
2) Always be prepared to spend the night (or two) with suitable equipment to minimize risk to life or limb. The level of preparation is very different in August than in January for obvious reason.

I recall during an attempted ascent of St Helens, version 1, back in May of 1977 winds on top of the "Dogs Head" that were so strong that we had to turn our faces to the side in order to breath -- directly facing the wind we couldn't exhale! -- we beat a hasty retreat -- we returned a month later and summited on a beatiful day. Weather measurement and prediction sure has improved since then.

Very interesting and useful information. As always, thanks for sharing.