The Chinook

December 5, 2009 4:07 AM

Forecast calls for cold and warm.

On January 22, 1943 in Spearfish, SD: The temperature rose 49 degrees in two minutes, from – 4 to 45; later the same morning, it dropped 60 degrees in 27 minutes, from 56° to - 4°. Plate glass windows cracked as a result of the wild fluctuation in temperatures caused by Chinook winds. The greatest 24- hour U.S. temperature difference in one place was set January 23- 24, 1916, in Browning, MT, at 100 degrees when it went from a low of -56° to a high of 44°.*

Snow eating is one way it's been described, old tales too.. It's a seasonal wind, like the Mistral. There is some overlap in the definitions but the Chinook can safely be labeled a Foehn wind. A Foehn wind is "a generic term for warm strong and often very dry downslope wind(s) that descend in the lee of a mountain barrier". That is the one illustrated above. My favorite wind though, is the katabatic. A downhill wind. Cold and dense it blows here on Earth especially in the Antarctic, and there on Mars too. (page 9 of 14.)

"Chinook" is a term guilelessly borrowed from the native people who reside on the windward side of the Cascade mountains in western Washington state by who knows who from the northern intermountain region. Named after the native Chinook, it originally and still does refer to an unseasonably warm wind.
Also BOC Teen Archer.

posted by vapidave (33 comments total)

Interesting post. I didn't know about Chinook winds before. Katabatic downhill winds are pretty weird, and can result in some really useful weather for sailing and windsurfing. Vassiliki in Greece being a great example. That said, this kind of effect is certainly not due to cold and dense wind, so perhaps it's a different phenomena, frequently mislabelled.

Sort-of on topic, I've been meaning to do a weather-related post for a while now. There are some brilliant websites dedicated to providing neat interfaces for weather-watchers. Windguru, Magicseaweed and XCweather being examples.
posted by iso_bars at 4:38 AM on December 5, 2009

I saw a Chinook wind once in Idaho. It came in February and melted all the snow in a couple of hours. It had wind gusts over 90 mph that felt like they would blow you off your feet. Scary and cool. And warm.
posted by RussHy at 4:52 AM on December 5, 2009 [1 favorite]

Note: All temperatures in the OP are Fahrenheit. See the Wiki article in the first link for Celsius.
posted by Kirth Gerson at 6:18 AM on December 5, 2009

After being mesmerized by all those tiny wind arrows on Windguru I'm ready to bring back Aeolus.
posted by Partial Panel at 6:24 AM on December 5, 2009

Chinooks can be pretty strange: you leave for work in the morning when it's -20 C, and by the afternoon it's 4C. A couple of years ago, IIRC, it was 20C on boxing day. This year in Calgary we seem to be having Chinooks every other day - it's confusing as hell.

A lot of people experience headaches, migraines and sometimes depression as a result of the changes in temperature/barometric pressure/ionic composition of the air. (Although the science here seems thin.)

Overall, I think Calgary would be a better place to live without the adiabatic winds.
posted by sneebler at 6:37 AM on December 5, 2009

This is unbelievably cool. I'm surprised I've never heard of this phenomenon before. Thanks, vapidave!
posted by Greg Nog at 6:43 AM on December 5, 2009

Fascinating post and big coincidence - I've been watching the onset of a Foehn this afternoon here in the Alps over the course of my first day on the mountain this season. Big concern for those of us in the ski industry as some forecasts are prediciting a weeklong spell of it which could destroy all our snow base under 1700m . . .

It's great working in the lap of the gods!
posted by protorp at 6:54 AM on December 5, 2009

Beware the pogonip.
posted by jquinby at 7:12 AM on December 5, 2009 [1 favorite]

We get chinook winds here, though not as extreme as the Spearfish example. It is quite amazing to watch the snow piles melt before your eyes. The downside is that a sudden melt like that can bring some really nasty flooding, because the snow turns to water but the still-frozen ground can't absorb any, so anyone downhill has to watch out.
posted by Forktine at 7:17 AM on December 5, 2009

Paul Metcalf has a section in one of his long poems (if poems they be) somewhere about the connection between migraines and siroccos, in which he lists a bunch of local names--the German foehn, the Croatian jugo, the Maghrebi ghibli, the French marin, the Canary Islands calima, the Andalusian leveche, the Catalonian shaloc, "the Maltesian xlokk" etc. (Wish I could find the original source--most of these names come from Wikipedia).
posted by rodii at 7:24 AM on December 5, 2009

I can't wait for the Climate Deniers to pick up on this and say "SEE! The climate was bad in 1940, WAY BEFORE we invented the Hummer! The planet's fine!"
posted by mccarty.tim at 7:50 AM on December 5, 2009

... Santa Ana, mistral, koembang, zonda, harmattan, brickfielder, tramontana, cierzo...
posted by rodii at 7:56 AM on December 5, 2009

Overall, I think Calgary would be a better place to live without the adiabatic winds.
posted by sneebler at 6:37 AM on December 5 [+] [!]

Really? Pretty much everyone I know immediately brings up the Chinook when the conversation turns to the brutal cold of Calgary's winter.

I know I'll be begging for a Chinook come midweek... deep arctic cold fronts get old fast.
posted by bumpkin at 8:14 AM on December 5, 2009

jquinby: Beware the pogonip

Oh, sweet jesus, QFMFT. Driving in ice fog is fucking terrifying even if you have awesome tires.

At point B on this little map is where I had the longest 10 seconds of my driving life, pumping the brakes and honking my horn and scaring the hell out of my passenger while trying to stop in ice fog. I'd seen the sparkle of deer eyes in my headlights well ahead of me, and discovered just how incredibly icey the road had gotten. My passenger didn't see the deer until we could see their outlines in the fog, when I'd finally slowed from 80 km/h to about 15.

The freakiest part was that I couldn't stop and I was going uphill.
posted by Decimask at 8:22 AM on December 5, 2009 [6 favorites]

I know I'll be begging for a Chinook come midweek... deep arctic cold fronts get old fast.

I lived in Calgary for three years a child, near Fish Creek Park. Our house faced West over the park, and you could see the band of the Chinooks as approached approached the city. People thought it was beautiful.

I, on the other hand, was extremely prone to migraines brought on by air pressure changes. Every time there was a Chinook I'd get a debilitating headache. I hated seeing those bands of cloud on the horizon. Pain was coming.

We moved away when I was about 12. I've never had a migraine since. I've also never been back to Calgary.
posted by generichuman at 8:24 AM on December 5, 2009

(Though I still get I-need-caffeine headaches, one of which made me type "approached approached.")
posted by generichuman at 8:25 AM on December 5, 2009

Katabatic is also the best vanilla map in Tribes 2!
posted by autodidact at 8:36 AM on December 5, 2009

The chinook is an element in many tall tales also (sorry if I missed it in your links). Like the time a some people went to church and had to tie their horse up the the steeple because the snow was so deep. A chinook blew in during the service and they came out to find their horses on the roof. Or the time a farmer tried to outrun a chinook with a fast team and wagon. He just happen to exactly match the speed of the wind; the horses were running in two feet of snow, the front wheels of the wagon were six inches in mud and the back wheels were leaving a dust trail.
posted by 445supermag at 8:45 AM on December 5, 2009 [2 favorites]

We get Chinooks (foehn winds?) in Boulder like hey, omg WIND! When I moved out here ten years ago it was a singularly strange and depressing circumstance to be on my bike, in my smallest gear, going full-out as hard as I could downhill and barely making headway.

The nice part is that yes, it will indeed warm up 20º in an hour or so... if you can hack being out in 50-60mph wind, that is.

The scary part is lying in bed at 3AM wondering if the roof is going to peel off, or the house is about to get up and start walking around like some russian fairytale.
posted by lonefrontranger at 9:04 AM on December 5, 2009 [1 favorite]

oh and there's a (legend? tall tale? anecdote?) floating around amongst the older bike racer set here in Boulder that one day Clark Sheehan was out training on U.S. 36 when the Chinooks came in and he got hit with a flying metal cattle trough. Having had to stop and stand cowering on the side of the road at the top of an exposed ridge once, desperately clinging to my road bike as the winds attempted to rip it out of my hands, and actually blew it out horizontal like a sail in my grasp? I kind of believe it.
posted by lonefrontranger at 9:10 AM on December 5, 2009

My favorite wind though, is the katabatic. A downhill wind. Cold and dense it blows here on Earth especially in the Antarctic, and there on Mars too.

Kim Stanley Robinson frequently referenced the katabatic winds in his Mars trilogy, and at times they actually factor into the plot.
posted by dhartung at 9:56 AM on December 5, 2009

I, on the other hand, was extremely prone to migraines brought on by air pressure changes. Every time there was a Chinook I'd get a debilitating headache. I hated seeing those bands of cloud on the horizon. Pain was coming.

Every time I see a Chinook arch looming over the Rockies, I double check my stock of ibuprofen. I'll take -30 with windchill over crippling migraines any day of the week.
posted by threetoed at 10:28 AM on December 5, 2009

lonefrontranger, I'd believe that story too! I've been knocked off my feet by a chinook before.

I grew up in southern Alberta and hated the wind, because really you're stuck inside just the same whether it's -30C or 10C and flooding in the basement from all the melting snow. But now that I've moved away I miss them a little. -30C for weeks on end gets old pretty fast.
posted by bewilderbeast at 11:36 AM on December 5, 2009

"The Santa Ana", by Joan Didion, is one of my favorite pieces of writing about these winds.

"On nights like that," Raymond Chandler once wrote about the Santa Ana, "every booze party ends in a fight. Meek little wives feel the edge of the carving knife and study their husbands' necks. Anything can happen." That was the kind of wind it was. I did not know then that there was any basis for the effect it had on all of us, but it turns out to be another of those cases in which science bears out folk wisdom. The Santa Ana, which is named for one of the canyons it rushers through, is foehn wind, like the foehn of Austria and Switzerland and the hamsin of Israel. There are a number of persistent malevolent winds, perhaps the best know of which are the mistral of France and the Mediterranean sirocco, but a foehn wind has distinct characteristics: it occurs on the leeward slope of a mountain range and, although the air begins as a cold mass, it is warmed as it comes down the mountain and appears finally as a hot dry wind. Whenever and wherever foehn blows, doctors hear about headaches and nausea and allergies, about "nervousness," about "depression." In Los Angeles some teachers do not attempt to conduct formal classes during a Santa Ana, because the children become unmanageable. In Switzerland the suicide rate goes up during the foehn, and in the courts of some Swiss cantons the wind is considered a mitigating circumstance for crime. Surgeons are said to watch the wind, because blood does not clot normally during a foehn. A few years ago an Israeli physicist discovered that not only during such winds, but for the ten or twelve hours which precede them, the air carries an unusually high ratio of positive to negative ions. No one seems to know exactly why that should be; some talk about friction and others suggest solar disturbances. In any case the positive ions are there, and what an excess of positive ions does, in the simplest terms, is make people unhappy. One cannot get much more mechanistic than that.
posted by gingerbeer at 12:10 PM on December 5, 2009

Beware the pogonip.

We get ice fog regularly here in the Spokane, WA area. It was so thick and prevalent over a long stretch of days a couple of years ago that there were tree limbs breaking off all over our tiny burgh from the weight of the ice that had attached to them. I remember our neighbor, who thought it was brilliant to park in his front yard because he doesn't have a driveway, frantically trying to move his snow-and-ice-bound truck because the old tree immediately above had already let go of 5 or 6 of its old, weak branches and he was concerned about not having a windshield soon.

Quite destructive, they also really screw up driving, as the ice coalesces out of the air and onto the pavement.
posted by hippybear at 12:28 PM on December 5, 2009

iso_bars is correct in saying that katabatic winds are not necessarily cold, apologies for any confusion.
posted by vapidave at 12:32 PM on December 5, 2009

Oh, and Stewart Copeland's post-Police band Animal Logic had a song, The Winds of Santa Ana. The song lyrics by Deborah Holland are essentially about depression, with the winds seen as relief rather than cause.
posted by dhartung at 1:37 PM on December 5, 2009

1985 was the coldest winter I ever saw. In just a few days in January, the temperature in Florence plummeted from normal (a few °C above freezing point) to -24°C (some report -27, even). Lowest ever recorded. I recall my dad called home from work (he was a chemist) to announce, somewhat proudly, that during the night the CCl₄ (carbon tetrachloride, a common solvent) pipes in the plants had frozen shut.
A fountain in a park close to home was suddenly turned into a skating rink, and some adventurous (or complete nutjobs) even took walks on the completely frozen river, something that only chronicles from medieval times would record.

What does this have to with the Chinook (Foehn, Mistral)? After a few miserable days, temperatures suddenly went from those lows to +18°C. And everything -everything- that was frozen solid, suddenly thawed. Including all the bursted water pipes, everywhere.
posted by _dario at 3:14 PM on December 5, 2009

Chinooks are not seasonal. We get chinooks year round here (Calgary). Their effects are most dramatic in winter, but there's nothing seasonal about them.

Would not trade them for anything.
posted by ethnomethodologist at 4:12 PM on December 5, 2009

See also: The 300 Club
posted by Rhaomi at 4:19 PM on December 5, 2009

I don't know. I grew up in Edmonton, where it's generally colder in the winter. I can handle that - you get used to it. It's great to have warm weather in the winter in Calgary, but I don't know if migraines and serious depression are worth the trade off, in any season. (Please note that this is not a complaint about Calgary per se. I'll save those for another occasion.)

But after all that, about the only thing we can do about it is either moving or complaining.
posted by sneebler at 5:06 PM on December 5, 2009

Another Calgarian here. I find I don't sleep well just before/during a chinook, but that could be just confirmation bias. I have a colleague who has to take Imitrex for his migraines just at the onset of a chinook, or he's in miserable pain for hours.

February chinooks are my favourites. By that time I've pretty much had enough of winter and some shirt sleeve sunny weather is a welcome respite. But I could you use a good dose of chinook right now. Calgary has just had a major snow storm and we're in for a deep freeze, -20C (-4F for those still getting imperially cold) for the next few days and the streets are looking like this. Municipal road crews do not plough residential streets, only major routes and bus routes, so most neighbourhoods will be impassable for days now.
posted by angiep at 7:20 PM on December 5, 2009

This reminds me of a Bavarian sexploitation comedy (PNSFW) I saw years ago, Die Jungfrauen von Bumshausen, where the women of an Alpine village convince their men that the Foehn has an aphrodisiac effect, with hilarious consequences.

Well, actually, the consequences were mildly amusing at best, at least in the super low-quality English dub I saw(with the English title of Run, Virgin, Run, which gives you a pretty fair measure of the level of sophistication), but this did remind me of it.
posted by strangely stunted trees at 6:53 PM on December 6, 2009