Ranger Kathryn's Arches

July 10, 2013

Collision course with an anvil

Filed under: Uncategorized — Kathryn Colestock-Burke @ 6:03 pm
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A towering cumulonimbus cloud denotes atmospheric instability in western Nebraska.

A towering cumulonimbus cloud denotes atmospheric instability in western Nebraska.

You can see it coming for a hundred miles or so out there in Nebraska, freeway bearing northeast and quickly-mushrooming anvil cloud bearing southeast, aiming to meet in another hour right where you have a motel reservation. It’s hard to imagine anything could sneak up on anyone on the plains, where you can see forever because the corn doesn’t obstruct a single sight line. No surprises. Just enormous storm clouds that seem to stalk you, perhaps menacingly, but that’s anthropomorphizing, as anyone can tell you that storms just barrel in without stalking.

Bright, they are. Cumulonimbus (Cb) cloud tops are full of ice crystals reflecting the brilliant sunlight, tricking you into thinking it is a Safe Thing when its Latin derivation suggests otherwise: cumulus “heap,” nimbus “storm/rain.” One look at these monstrous upwellings of air and water vapor and you sense that its unsettled nature will likely bring precipitation.

Dangly clouds are not my favorite.

Dangly clouds are not my favorite.

Just to the north, the lowest layers seemed to be dragging heavily from the cloud bottom. Seeing no rotation, I didn’t get the sense of a tornado; it was nonetheless disconcerting. The cloud was dangling. Dangling clouds, to midwesterners, are often unsafe. These photos taken at 70 mph with my iPhone don’t do justice to the mysterious nature of  the pannus variety of cumulonimbus, but at least now Wiki has given me a name for it:

Fractus clouds (scuds) are small, ragged cloud fragments that are usually found under an ambient cloud base. They form or have broken off from a larger cloud, and are generally sheared by strong winds , giving them a jagged, shredded appearance. Fractus have irregular patterns, appearing much like torn pieces of cotton candy. They change constantly, often forming and dissipating rapidly. They do not have clearly defined bases.

Sunset illuminates a cloud-shred.

Sunset illuminates a cloud-shred.

Thirty minutes later, this towering giant was so electrically charged that I counted 28 flashes of strobe-like lightning in 60 seconds. It felt alive, some sci-fi monster rumbling in its innards, ions and updrafts and unstable air converging on North Platte just outside my motel room. I stood alone at the  west-facing window and trembled involuntarily, several hundred megawatts of electrical power staring me in the face; until it weakened, there would be no sleep.


  1. My husband shot video of your excellent Geologic Symphony talk in June. You asked us for a copy, but we feared our audio had not recorded. The audio did work 🙂 and I burned your DVD tonight. So I intend to mail your DVD tomorrow.

    Comment by Roxie — July 10, 2013 @ 7:27 pm | Reply

    • This is wonderful news! There was a tense moment when your new camera was acting as if it might not have recorded. I am so glad you got your ‘souvenir recording’ and I truly appreciate your sending it my way. Watching it will help me become a better interpreter, Roxie. Thank you!

      Comment by Kathryn Burke — July 10, 2013 @ 9:38 pm | Reply

  2. Teachers teach – anytime, anywhere, anyhow.
    Nicely done.

    Comment by leroque — July 11, 2013 @ 7:28 am | Reply

  3. Wondered how the Rockies trip went after hearing about some flooding up there or other extreme weather? You might enjoy this post? http://huckberry.com/blog/posts/storm-troopers

    Comment by midsummerman — July 11, 2013 @ 10:40 am | Reply

    • Wonderful trip — am composing a few blog posts about it, which should come out in the next couple weeks. Flooding kept us away from Banff but all other parks and areas were great!

      Comment by Kathryn Colestock-Burke — July 11, 2013 @ 11:23 am | Reply

  4. I have included the pictures I took of you during your presentation as well.

    Comment by Roxie — July 11, 2013 @ 11:41 am | Reply

    • Thanks! I’m back in Minnesota for a few wks but will get them all when I return next month! You’re the best!

      Comment by Kathryn Colestock-Burke — July 11, 2013 @ 11:44 am | Reply

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