Our first blizzard of the season is hitting us right now: snow is pouring down, the wind is howling, temperatures are in the single digits °F and dropping, and we’re nearing white-out conditions. We’re staying indoors.

I don’t think our snowflakes look anything like the picture above (from this gallery of snowflake photomicrographs). They’re tiny and powdery, and flying by horizontally at 30 or 40 mph.


  1. says

    That snowflake pic reminds me of the postcards I am sending out this year for the holidays. Which reminds me that I have been wondering why the US Postal Service doesn’t just issue a snowflake stamp for the winter. It could be used for holiday mail and just winter mail in general… Instead we get Christmas Knits, Nutcrackers, and a Virgin with Child… Thanks, post office…

  2. says

    Dust of Snow – Robert Frost

    “The way a crow
    Shook down on me
    The dust of snow
    From a hemlock tree

    Has given my heart
    A change of mood
    And saved some part
    Of a day I had rued.”

  3. Nerd of Redhead says

    Ah yes, horizontal snowing. Never looks like it lands, but it still piles up. In the Superior lake effect regions, there can be horizontal snowing even with clear skies if the wind is strong enough. Nothing like having to snowblow out your driveway on a clear day.

  4. Sili says

    Well, you’ve obviously forgotten to tell the flakes you love them and played nice music for them – that’s why the bleeb they’re ugly.

  5. LisaJ says

    Enjoy your first blizzard, PZ. We’ve got piles here in Ottawa already, which is so not fun with this damn bus strike we’ve got going on. Argh, so angry. Stay warm!

  6. mothra says

    I just trudged 8 blocks to my local university, turned to The Thomas Jefferson Hour on the radio, and, after this bit of blogging will quietly get some work done.

  7. bigjohn756 says

    Oh, yeah, I forgot to add that it’s 70 and cloudy here. The humidity is 63% and the wind is SSW at 22 mph. The only problem is to get warmer weather you have to live in Texas.

  8. Patricia, OM says

    Snowing hard here.
    My brave chickens are out scratching for grass. The Aussies & Chileans are out in the snow too!

  9. gastropod says

    Only a half inch of sleet here in Marshall, and you’re supposed to get a foot of snow in Morris?? Send some south, PZ!

  10. says

    Alas, snow…

    I envy you guys, it’s a rare ocasion when I get to see that much snow and for the most part I have to travel a little far just to enjoy it :(

    Ok, see ya later. I’m going to get a sun tan at my backyard and drink a really cold beer ;)

  11. SC, OM says

    I just trudged 8 blocks to my local university,

    Now I’m reminded of that depressing episode of Little House on the Prairie. Be careful on your way home!

  12. 6EQUJ5 says

    Here in Alhambra in Los Angeles County it got so cold last night that at 4 am I closed my bedroom window. It was 61.6 F inside!

    Woe was me.

  13. BobC says

    How lucky some people are to be able to enjoy a violent snow storm. It’s a boring 78 degrees where I live near Fort Lauderdale.

  14. Nick Gotts, OM says

    The picture is not a snowflake – it’s a snow crystal, of which there are many to the flake. If you have a cold outhouse and a microscope, look at some of your “flakes” through it, and I think you’ll find it’s made of such crystals. (Each one of which must, of course, be personally crafted by God, since we know the second law of thermodynamics forbids increaes in order.)

  15. Jason A. says

    I’ll take a dynamic snowstorm over boring warm weather any day. Here in arkansas we never get any real snow, just bitter wet cold and maybe sleet. I try to get out every winter and visit somewhere with real winter weather.

  16. RamblinDude says

    Down here in Florida we sometimes have a problem with the wind whipping up, but it’s also bit of a relief when the mosquitoes blow past at 30 or 40 mph.

  17. Nix says

    From a little further north than you, no snow this year so far, just a bit of frost: temperatures at 3C and rising right now. The Gulf Stream is useful that way… but I’d prefer some snow. Up in Yorkshire my parents have had snow on the ground for two weeks.

  18. LeeLeeOne says

    Woke up to -20 F. It is hovering around -18 F at noon. I cannot see across my yard and street to look at the neighbor’s driveway. The wind is insane and have a lot of branches in my yard. What a mess! But I have a wood-burning fireplace and am staying toasty. Ahhh, a roaring fire, a cup of hot cocoa, and a good book. Yep, it’s winter officially now.

  19. Peter Ashby says

    Sounds a mite colder than here in Eastern Scotland. We’re hovering around 0C/32F +/- 3or4C. I have run on snow for the first time this year, we got about 2 inches. A week ago I went out for a run gone 4pm (dark), i noticed white frost on the footpaths so ran onto the road, turned right and my legs just went out from under me. Road was slick with black ice. Banged my knee and elbow quite hard.

    Mind you I’d rather run in the winter, you can do more if you’re cold than if you’re hot, like put on more clothes or run faster.

  20. negentropyeater says

    (Each one of which must, of course, be personally crafted by God, since we know the second law of thermodynamics forbids increaes in order.)

    And it’s perfect, look how beautiful it is, and as the great philosopher E. Hasselbeck teaches us, if a handbag requires a designer, a snow crystal must also require one.

  21. Janine, Insulting Sinner says

    Posted by: SC, OM | December 14, 2008

    Now I’m reminded of that depressing episode of Little House on the Prairie. Be careful on your way home!

    I am so happy I have been able to repress any memories of having watched that show. I have no idea what you are talking about.

    Now if I could only do the same with all of those Brady Bunch episodes.

  22. recovering catholic says

    Thank you, Great Spirit, for posting the Robert Frost poem!

    And I sincerely DO envy you, PZ and all you other snowbound people. I’d choose below zero, several feet of snow and 40mph winds every time over 90 degrees and 100% humidity (which we get way too much of here in the armpit of Illinois). I must admit, however, that the gift of a small electrical generator from our older son for squidmas last year makes dealing with snowstorms and electrical outages much easier…

  23. Jim Thomerson says

    That storm will get to Austin sometime tonight. Tomorrow will be down in the 50’s, but no precipitation.

  24. Ian H Spedding FCD says

    Same blizzard here in Fargo – horizontal snow, neighbouring buildings disappearing periodically and I’ve seen only one vehicle moving on the road outside all day. It’s around 40 degrees F below freezing point, windchill is more like 70 degrees. My van certainly won’t start in these temps, the wife’s car might once I get it plugged in. Thing is, I get all these strange looks from the locals when I say how much I like snow. Weird.

  25. 'Tis Himself says

    No need to thank me.

    Oh, no, you deserve some kind of thanks. [Loads shotgun with alternating deerslugs and double-ought buck.]

  26. Janine, Insulting Sinner says

    Thank you, ‘Tis Himself. That was even worse than when I linked to a Barry Manilow song.

  27. SEF says

    The picture is not a snowflake – it’s a snow crystal

    Not quite. As a bare minimum that’s a pair of twinned crystals, rather than a single crystal per se.

  28. Nepenthe says


    if a handbag requires a designer, a snow crystal must also require one.

    I’m seeing images of hell now. Spending an eternity carving out intricate crystals, which will fall to earth and become affixed to a dog’s ass.

  29. sdej says

    Its getting cold all over. We had to turn of the air conditioning in our tent here in Kuwait last night.

  30. SC, OM says

    Keep tempting me. I can start popping out Little House puns anytime. You should be careful about luring gals wilder than yourselves into blog wars.

    (Actually, I can’t now since I have papers to read, but there’s always later…)

  31. MReap says

    Here in the Tropics of MN (SE corner) we’ve gone from 8inches of snow on the ground to none over night. Right now we have light rain. Supposed to drop to 3F tonight. We have a wind chill advisory for midnight to 6pm Monday w/wind chills expected to be -25F or so. Nice combination – subzero temps and standing water. Just can’t wait for the commute tomorrow!

  32. Jadehawk says

    yeah, that would be the same blizzard that just came through here. good thing i didn’t have to leave the house :-p

  33. DaveG says

    I too have snow envy. Here in Rochester, NY we have grass peeking through a light carpet of snow. At least in snowed! Better than CT, where a sighting of your iridescent twinned crystal would throw the state emergency machine and meteorillogical media into a frenzy. School Closings! Travellers’ Advisories! And Nutmeggers’ aggressively selfish driving would be amplified into hazardousness by the perceived danger and lack of commensurate driving skill.

    Speaking of meteorillogy on TV, how many other professions with such a large and defensible fudge factor, other than a certain retiring politician’s or pro football players who never approach the ball and so get hit minimally, pay so handsomely?

  34. charley says

    Here’s a dumb question about snowflakes. Even though there are an endless number of complex flake patterns, the arms of any given flake are ridiculously similar to eachother. As the arms grow out from the middle during crystal formation, what causes them all to put the same tiny spikes in the same places when there are so many other possibilities? It’s as if each arm knows what the other is doing. Is this just due to environmental conditions? I’ve seen videos of snowflakes forming in a static environment under a microscope, and they still form with this comlex symmetry. Temperature, humidity and air movement don’t seem like enough to account for it, but I don’t know what else it could be.

  35. Bob Munck says

    Here’s Morris currently:

    Temperature: -5.0 °F
    Dewpoint: -9.0 °F
    Humidity: 82%
    Wind: N at 19.0mph
    Wind Gust: 40.0mph
    Pressure: 29.55in

    Unfortunately the only local weather station (here) doesn’t have a webcam, though I imagine it would be a blank white screen. That’s quite an impressive temperature drop.

  36. Alex says

    Snow and cold? its an unseasonable 68F here in NC and Im loving it. I hope to never see another snowflake in my life or to experience cold temperatures. Id kill myself before Id live in MN. Seriously.

  37. SEF says

    Is this just due to environmental conditions?

    Yes. The different possible directions of crystal growth are each favoured by slightly different conditions. Since the whole of the crystal is in almost exactly the same environment at the same time, its arms grow in almost exactly the same way as each other. And since that environment changes with its path through the clous, quite separately from the paths of all the other budding crystals being tossed around, there’s quite a lot of variety between them.

  38. SEF says

    Oops: “clous” should have been “cloud”. I must have missed the intended letter. It certainly wasn’t anything to do with claus …

  39. Janine, Insulting Sinner says

    Posted by: SC, OM | December 14, 2008

    Keep tempting me. I can start popping out Little House puns anytime. You should be careful about luring gals wilder than yourselves into blog wars.

    (Actually, I can’t now since I have papers to read, but there’s always later…)

    Now I am going to use MAD! As much pain as it brings me, I have Lola. Hell, I brought her through the rain. I even have a sister named Mandy. (No. Really!) And if I am forced, I have the ultimate version of that song. It is rather angelic.

    This is my only warning.

  40. SEF says

    the snowflake pictured has octagonal symmetry

    No, it doesn’t. Count again.

    As mentioned earlier, it’s a pair of twinned crystals rather than a single crystal – where the twinning occurred quite soon after seeding so that it led to the growth of two sets of almost identical length arms (2×6 = 12). One plate will be in front of the other.

  41. says

    45/45 here – fahrenheit and mph, wind from the south since last night. (Central Illinois) The air mass charging over our state must be colliding with one from the North over yorus.

  42. Jerry Billings says

    Woke up this morning and saw snow on the ground. This is unusual here in Portland OR. Checked the TV for the weather report. It said, “Chance of snow.” Don’t weather forecasters ever look out of the window?

  43. Tony Popple says

    Mike Procario said

    “I am surprised a blizzard in Minnesota even warrants a blog posting. ”

    Complaining about the weather is a long-time Minnesota tradition. It is part of the whole “Minnesota Nice” thing. It is always a safe topic because everyone has to deal with it.

    It has been said that it takes a village to raise a child. In Minnesota, it takes a village to pull your car out of a snow bank.

  44. Jadehawk says

    oh and btw, after living in California, I STILL like the weather here more. though it would be nice if the snow was occasionally the fluffy fun stuff, rather than the rock-solid stuff that feels like sand-paper when it comes down

    and Florida is how I imagine Hell feels like: hot, superhumid and more mosquito-infested than the Midwest (that’s quite an achievement!), and all year ’round, no less :-/

  45. Kemist says

    We’re staying indoors.

    No, people. That just means snow-mobile, ski & snowshoe time. You know, with a cosy chalet and coffee-baileys for everybody.

    Don’t look at me like that. Here in Quebec you either love winter or you just freak out. We get like, 6 months of it. Last winter we got a grand total of over 500 cm snowfall, from mid-november to april. I’m not staying indoors for 6 months.

  46. Chris says

    Well, here in Boulder, it’s 3F, with a light dusting of snow. Sort of odd actually, as it was 50F yesterday.

  47. negentropyeater says

    Myers is in a blizzard,
    Barman rises dizzily,
    Myriad brains sizzle,
    A snazzy slimier bird.

  48. rp says

    Here in sunny Edmonton, it’s currently -25C, wind chill -38C, and only 6 or 8 inches of snow. Last night it got to -31C, and I don’t want to imagine what the windchill was. I wish I could stay in until it gets up to -10 or so, but I have doctors appointments.

  49. says

    As I remember, it was 1973 when Las Vegas got 8 inches of snow, which is extremely rare. Most people here didn’t know how to drive in the snow but we drove anyway. The roads were teeming with traffic, everyone saying, “let’s go see what the Strip looks like” or, “Let’s go see what Downtown looks like” or, “Let’s go see what Red Rock Canyon looks like.”

    During the two hours my family and I were on the road we saw seven finder-benders and numerous cars in ditches (we were one of them but we managed to get back on the road).

    It was a fun day, a bumper car day.

  50. 'Tis Himself says

    Florida is how I imagine Hell feels like: hot, superhumid and more mosquito-infested than the Midwest (that’s quite an achievement!), and all year ’round, no less

    Also the annual hurricanes and palmetto bugs. These are huge, flying cockroaches up to 40 mm (1½ inches) long.

    You’d have to pay me large amounts of money to live in Florida.

  51. RamblinDude says

    Here’s a dumb question about snowflakes.

    Scientific American usually comes through.

    Also, THIS ARTICLE points out that:

    The six arms of a snow crystal all grow independently, as described in the previous section. But since they grow under the same randomly changing conditions, all six end up with similar shapes.
    If you think this is hard to swallow, let me assure you that the vast majority of snow crystals are not very symmetrical. Don’t be fooled by the pictures — irregular crystals (see the Guide to Snowflakes) are by far the most common type. [bold type added] If you don’t believe me, just take a look for yourself next time it snows. Near-perfect, symmetrical snow crystals are fun to look at, but they are not common.

  52. Katrina says

    55F and raining here in Naples, Italy. More of the same for the next three days. The clouds lifted a bit today and we could see snow dusting the tops of the Apennines and Vesuvius.

    Ah, winter in a Mediterranean climate.

  53. Jadehawk says

    Also the annual hurricanes and palmetto bugs. These are huge, flying cockroaches up to 40 mm (1½ inches) long.

    You’d have to pay me large amounts of money to live in Florida. as long as the critters don’t bite, i could live with it. i am however allergic to mosquito bites (and just to spite me, mosquitoes LOVE to bite me), so Florida is out of the question. North Dakota Summers are hard enough to get through. But hurricanes sound decidedly worse than the occasional blizzard

  54. gaypaganunitarianagnostic says

    Got sbout two inches of snow Wednesday. Here in the south-east corner of Texas we get hurricans more often than snow. today was t-shirt weather.

  55. jahigginbotham says

    #1 There are some 39c stamps with 4 different designs. They should be reissued.

    #56 Doh! I can’t count.
    Nor read the caption under link?

  56. varlo says

    Is wondering what part of Florida has midget palmetto bugs*
    no more than 40 cm long?

    *Not a Florida native; I know that Palmetto bug is local nomenclature for a COCKROACH ON STEROIDS.

  57. varlo says

    Belatedly respionding to Clinteas (#6) six years with no snowflake: Clint, I will see your six and raise you 18 more years.

  58. Crudely Wrott says

    Cold. Cold! Harshly lit by a wan sun filtered through airborne ice. And raw. Wet, half frozen mud and icy needles in the wind. Slick, dangerous underfoot, threatening and grim overhead. Numb fingers and clumsy feet.

    Yep. Happens every year just about this time. Accompanied by freshly dusted off exclamations of astonishment.

    Me? I just pull on the long handles and go on.

    Come spring, will we hear the same claims of novelty? Shall a crocus be a surprise?

  59. SEF says

    They are symmetrical for the same types of reason that other crystals have symmetry. Atoms and molecules of a given type fit together as best they can and their particular configurations restrict the symmetries available to them. They can’t join on in just any old orientation. Furthermore, some directions of growth are easier than others; and the balance can shift in favour of different ones according to environmental conditions (eg towards plates, columns or needles).

    So, to be a crystal at all (rather than a glass, say), requires some symmetry – viz translation, for a start, and, optionally, rotations and reflections (with limits on the combinations of those too). But that just sets the crystal “habit”. The specific outcome depends on the growth conditions. Whereas crystals growing within rocky matrices are trapped, ice in a cloud is free to grow in whichever direction is easiest at the time; and there’s an inherent symmetry to those easy directions for each substance.

    See also #54.

  60. crookedmouth says


    Thanks for bothering to answer SEF, but it doesn’t help much! I understand (vaguely) the basic forces in crystal formation and it follows why a *simple* shape should ensue (cubic or the like).

    What is it that brings symmetry to the *complex* shapes we see in the snowflakes? How does the snowflake “know” that (say) its 12 o’clock arm should have pentagonal lobes increasing in size by a factor of 1.1 as they progress towards the tip. How does it “know” that the 3, 6 and 9 o’clock arms should be identical to the 12 o’clock one. How does it “know” that the 2, 5, 7 and 10 o’clock arms should be different from the others by a factor of 0.9? etc etc.

    Surely that isn’t a result of “simple” bond patterns (I can see how this might go! and no, I’m not an ID’er!) If all snowflake crystals are different (if you believe the folklore), then what makes them different yet *still* so self-consistently symmetrical?

    Question no 2: Am I going to wish I hadn’t asked Question no 1?

  61. rookedmouth says

    PS it would be nice to see some of that symmetrical stuff ’round my neck of the woods at the moment! SE England is more likely to be dull, dreary & wet this time of year.

  62. SEF says

    (a) They aren’t as consistently symmetrical as you think.
    (b) Do re-read #54 but I’ll try to elaborate.

    Let’s assume you do indeed accept that molecules fit onto a growing crystal in particular directions (not completely unlike lego pieces). Hopefully you are also able to appreciate that it can be easier to build in some directions than others (or, conversely, to lose material in some directions). What’s less obvious is that the easy direction can change according to environmental conditions.

    So budding snowcrystal A already has, from its seed, a 6-fold symmetry around an axis. Suppose it spends some time in region X where needle growth is promoted and it starts getting long points. Since the whole crystal experiences almost exactly the same conditions at the same time through being at a particular place in the cloud, all its points inevitably grow about the same amount and in the same way. They don’t have magical knowledge of what the other points are doing.

    Then suppose A gets tossed into region Y where it’s easier to grow by spreading out into plates. Its needles may wear away a little but fill out. Meanwhile, another budding snowcrystal B, starting in Y, has grown a large central plate. Moving into X will add needles onto the points of that – giving quite a different shape from A.

    A further snowcrystal C may be stuck in a region Z where columnar growth is the easiest option. If it then moves to Y it will get plates at each end of its column quite a way apart. If the original seed was a twinned crystal, then it could grow plates (and needles) in the alternate orientation (still stuck growing at about the same rate as each other through being in the same place in the cloud at the same time) and hence look like a 12 pointed one from the right angle (looking down the column axis onto the twinning plane).

    If A and B move into region Z they will thicken up and perhaps lose some parts of plates or needles such that new lacy details will form on those when they next return to regions X and Y.

  63. says

    The article on snow with the picture that PZ originally linked to had an explanation. Not everything is understood. However, the surface of a snowflake is “competing” for loose water molecules. If there’s a dry crystal corner, it sticks out more, so touches more molecules, so gets bigger, so hits even more molecules. Meanwhile, it’s scouring the molecules out of the environment of its surroundings. So you get a point and a low spot. Part of the symmetrical variation is caused by slight temperature variations. At some temperatures (-2?) the crystal is covered with a thin, quasi-liquid layer, which makes it easier for water molecules to bounce around and regain escape velocity. When they clump together, they become less “buoyant” and more likely to slow down and join the crystal. At slightly lower temperatures, the crystal dries out again and begins to grow quickly – many times faster than a few moments before. After that it’s not clear to me but such tiny variations are what makes the feathery “dendrite” crystals grow. Each snowflake is a single crystal unless it’s a twinned one like the one in the photo.

    Monado in Toronto, where we’ve had cold winds all day, including a few trees and powerlines down, but thankably little snow.

  64. crookedmouth says

    #85 & #86

    Thanks. I think that helps. It’s a question I was mulling over in my mind recently but was too lazy to do anything about finding an answer. My (layman’s) interpretation is that the molecular bonding does affect the complex symmetry but only at a level removed – the complex symmetry comes from variable environmental conditions acting “symmetrically”. Am I right?

    Once again, thanks for taking the time (and, no, I didn’t really believe that snowflakes are sentient, but they certainly are magical)