A microburst in Arizona

August 15, 2015 • 8:45 am

A burst is a column of cool air that, being heavier than warm air, sinks to the ground rapidly and dissipates, causing high winds. When a small portion of such air is laden with water from a storm, and drops to the ground, you get the famous microbursts. (We had one in Chicago about a decade ago, which knocked down nearly every lamppost and tree on my block.) Here’s a particularly vivid one from near Tucson.

A time lapse of a strong thunderstorm that dropped a couple of wet microburst. One in particular was captured really well in the time lapse thanks to the sun peaking out to the west. Notice how the ball of rain falls from the sky and starts separating before hitting the ground. Once it hits the ground you can see the power of microburst as it expands similar to the ripple you would see when you drop a stone in water.

Here’s a figure from Wikipedia that explains what’s happening in the video:Screen Shot 2015-08-15 at 8.41.49 AM that shows what’s happening.

h/t: John W.

23 thoughts on “A microburst in Arizona

    1. I drove through Wyomihg once, during a rainstorm. Absolutely beautiful. It brought to mind my favourite childhood books – My Friend Flicka – which took place in Wyoming.

      1. I have had similar experiences driving through various big western states. Huge thunderheads towering in the sky, black rain shafts all around us, and you could see the ‘currents’ of rain shifting and moving in them. My girlfriend (now my wife) was very awed. Surprisingly, she did not know what rain shafts were since she came from the eastern US and did not have much horizon to see when she was growing up.

        1. I once had the misfortune of driving through the Canadian prairies.

          We make jokes here in British Columbia, the land of narrow valleys, about the poor folks from the prairie provinces who cannot handle our narrow, twisty roads. Heh. Driving across the prairies scared the shit out of me, because the winds were *so* strong that I always felt as if I was going to be blown off the road or into oncoming traffic.

          I’ll take a narrow river valley any day tyvm.

            1. There is a bridge in my town, that goes right over a big river. It is incredibly windy. One day a student was riding his bike across the bridge, en route to the college. He lost his homework. It was blown right off his shoulders and into the water below.

              Sounds like a convenient story to avoid doing homework no? Well, one of the college instructers was driving across the bridge at the time and saw the whole thing.

              1. Ah, the sort of coincidence some no doubt saw as a miracle!

                Don’t think I’d be riding a bike at that place in those conditions!

    1. Yes, even for large airliners. I remember an incident quite a while back when a heavy was on final and got pushed down and crashed. Since then the use of doppler radar has been implemented at big airports to help anticipate the danger.

      1. More usefully, onboard wind shear detection and alert systems have been mandated in all jetliners since the early 90s (as a result of investigations into just such crashes as you mention). These provide more precise information in the direct path of the equipped aircraft than ground radar can.

  1. Had one here in
    San Diego this May. It knocked down half the trees in the park across the street from me.,flooded my living room through the front door seals. Pretty amazing.

    1. I suspect we had one here in our neighborhood last summer. We went out for dinner across down, and there was a good thunderstorm where we were. After the storm was over and all was calm we drove back to our part of town. As we approached our block we were suddenly surrounded by downed trees, downed powerlines (some were sparking), and all the lights were out. It was a very intense, localized wind. We had to weave our way around trees to get to our house. Our neighbor across the street had a huge oak tree lying across her house roof and car.

      1. Indeed these can be very localized. There’s a house nearby that is the only one with it’s shutters half off and fence bent and broken. I’m sure some reported are actually tornadoes.

  2. We get them pretty regularly in northern Utah, especially along the mountainside where I live. A couple years back I had put up a shade canopy in my yard, and tied it down at several extra points to protect from the wind. A few hours later a burst came along. The ropes held but the sheer force made clean cuts right through the steel legs.

  3. Had one in Tempe several years back that ripped the pop top off the ’68 VW Camper. Downed a majority of the trees in the area, too…including the giant eucalyptus the Camper was parked in front of — but the tree went at 90° to the Camper and so took out the carport in the next apartment over, as well as the car parked under said carport….

    They’re not quite as destructive as a tornado, but they’re as close as you can get in destructive power without actually being a tornado. At the very least, you’re guaranteed to be looking at a lot of cleanup of blown debris.

    b&

  4. Spectacular footage! Thank you for submitting it, John W.!

    As long as we’re telling our storm stories, here’s mine. I was a kid in Oregon in 1962 when the winds began to pick-up severely. Noticing that a sapling we’d recently planted was whipping around and bending in half, I’d gone out to try to tie it more thoroughly to its stake, only to end up hanging onto the stake itself for dear life.

    Meanwhile the neighbors-across-the-street’s back deck roof had blown loose, lifting up like a strange balloon with its plexiglass ceiling still intact and supporting two-x-fours dangling down from all sides. It sailed up over their roof, across the street, and crashed into ours, and suddenly there were big chunks of lumber raining down around me.

    At this point I apologized to the sapling and crawled back to the house as best I could. Meanwhile we’d lost power, but the large front window was miraculously still intact, and my mother and I took the mattresses off the beds to stand in front of the window, lest it subsequently burst and send shards flying inward.

    The phone lines lasted a bit longer, long enough for Dad to call from the docks (he was manager of operations for a shipping company) where a vessel of theirs–a large freighter–had torn loose from its moorings, been propelled down the Willamette River, and into one of the Portland bridges.

    When winds eventually abated, parts of a three-state, one-province area were left with severe damage, weeks-long power outages, cancelled schools, etc. The event was immediately dubbed the Columbus Day storm, and remains one of the most severe weather events in recent times. See:

    https://en.wikipedia.org/wiki/Columbus_Day_Storm_of_1962

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