Friday, September 9, 2011

Microbursts!

Many of you unfamiliar with the desert southwest might wonder why our storms can be so damaging.  On a recent road trip, I snapped a shot of this microburst in the middle of the desert.  A microburst is a small, very intense downdraft that descends to the ground resulting in a strong wind divergence. The size of the event is typically less than 4 kilometers across. Microbursts are capable of producing winds of more than 100 mph causing significant damage. The life span of a microburst is around 5-15 minutes. When rain falls below the cloud base or is mixed with dry air, it begins to evaporate and this evaporation process cools the air. The cool air descends and accelerates as it approaches the ground. When the cool air approaches the ground, it spreads out in all directions and this divergence of the wind is the signature of the microburst. In humid climates, microbursts can also generate from heavy precipitation.  It's a pretty crazy moment of chaos as wind from all over attacks your home.  Things fall down all around you.  Trees are uprooted.  Hail can smash through your windows.  Water can come crashing through your roof.  Rain comes in from under your door because it is raining sideways instead of from the sky.  It's intense and you wonder....will we survive?  I've only been in several of these and they are nasty. Our streets turned into rivers here. If you are on the road when one hits, pull off to the side and NEVER drive through washes.  Wait until it passes by or risk the chance of being swept away in a flowing wash or have a mesquite tree fall upon you while you're trying to maintain your speed at 45 miles an hour.  Yeah...it once almost happened to me when I first moved to Tucson.  Scary stuff, but cool to watch from inside a safe place.

1 comment:

  1. One of the beauties of Arizona.
    Would turn out great as a painting!

    ReplyDelete

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