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continuing climate craziness

October 26, 2010

And again, an alliterative appellation, plus primarily a paltry post.

Today it is cool, dry, and windy here in town.  Blow-me-off-the-road-when-I’m-biking windy.

This, in case you were wondering, is what blow-me-off-the-road windy looks like compared to normal autumn breezes.

In fact, it’s so dry and windy, we’re under a fire weather warning (may it end more safely than our last fire weather warnings).  And yet, the western slope is expecting a foot or two of continuing snowfall, and it’s snowing lightly just 10 miles or so up the canyon.  This place boggles my southeastern-weather-attuned mind.

Thanks for tuning in to today’s “what the hell, weather?!” moment, brought to you by orographic lift.

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6 comments

  1. What is getting my attention is that we’ve not had proper winds since the late ’80s.

    Like ‘blow down the overpass they were building over Walnut on Foothills’ proper. 100 mph gusts for two days proper.

    Funny, though. You get used to it. Come to appreciate it (especially when it’s not a bora, like this week, and is instead a chinook in January, raising the temperatures from the 10s to the 60s by the time you leave the house in the morning). Folks in places with (mostly) boring weather will never understand the attraction, but at least it’s interesting.

    This year, what with La Nina, may finally put an end to that absence of wind. But I thought that last year.


    • Goodness, if I have yet to experience proper Colorado winds, I’m not sure I want to. I’ve lived through a hurricane in NC, and once is enough, thankyouverymuch. I guess there are fewer trees to blow down here, though.

      I suppose you don’t need trees if you can blow down overpasses instead *eyes widen*

      Also, http://www.universetoday.com/76724/most-intense-storm-in-history-cuts-across-the-us-as-seen-from-space/ . Apparently this was unusual, though honestly, even living here for ❤ years, I didn't think it was all that unusual.


      • FWIW, the difference here is that the steady wind speed is O(40mph) in “proper” winds, and the top gusts are O(100mph). Record for Boulder (which happened in the early 80s) is 144(?)mph. Which probably made people here say, “What the FUCK?” But there it is.

        Sure, that’s (relatively) low “steady” wind speed for the purposes of this conversation, but I can’t help but wonder whether or not the impulse in pressure force matters as much as the pressure difference. A woman I dated briefly in grad school said a neighbor’s trampoline was blown away in the storm and was lost. Seems like the kind of thing that wouldn’t be lost.

        P.S. Is that “lowest air pressure” altitude corrected? ‘Cuz that would make a difference.


  2. Ah. I see that it is, but they keep saying “non-hurricane” which isn’t really what I thought they were saying.

    OTOH:
    “General Circulation Models (GCMs) like the ones used in the 2007 IPCC Assessment Report do a very good job simulating how winter storms behave in the current climate, and we can run simulations of the atmosphere with extra greenhouse gases to see how winter storms will behave in the future. The results are very interesting. Global warming is expected to warm the poles more than the equatorial regions. This reduces the difference in temperature between the pole and Equator. Since winter storms form in response to the atmosphere’s need to transport heat from the Equator to the poles, this reduced temperature difference reduces the need for winter storms, and thus the models predict fewer storms will form. However, since a warmer world increases the amount of evaporation from the surface and puts more moisture in the air, these future storms drop more precipitation. During the process of creating that precipitation, the water vapor in the storm must condense into liquid or frozen water, liberating “latent heat”–the extra heat that was originally added to the water vapor to evaporate it in the first place. This latent heat intensifies the winter storm, lowering the central pressure and making the winds increase. So, the modeling studies predict a future with fewer total winter storms, but a greater number of intense storms. These intense storms will have more lift, and will thus tend to drop more precipitation–including snow, when we get areas of strong lift in the -15°C preferred snowflake formation region.”

    Oh. Crap.


    • This is all super fascinating. Thanks!


  3. Hmm. Looks like my graph link is continuing to update. That’s kind of nifty, but also annoying, given the caption it has.



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