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  1. #1
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    More on Lightning

    This public info statement was on weatherunderground this a.m., some interesting stuff:

    .. Lightning awareness week - the science of lightning...

    Lightning remains a random... chaotic and dangerous fact of
    nature. Lightning has been seen in volcanic eruptions as
    well as extremely intense Forest fires in the west... but is
    most often seen in thunderstorms.

    At any given moment... there are 2000 thunderstorms in progress
    across the Earth. Thunderstorms form as a result of three
    parameters: moisture... instability and lift (such as fronts...
    sea breezes or mountains) forcing the air to rise. Clouds in a
    thunderstorm typically rise to elevations between 30000 and
    40000 feet (5 to 7 miles) but can rise in upwards of 60000 feet
    (10 miles).

    Temperatures higher in the atmosphere are much colder and ice
    forms within the storm cloud varying in size from ice crystals
    to hailstones. These particles move within a storm and collide
    with other particles causing separation of electrical charges.
    The lighter ice crystals become positively charged and rise to
    the top of the storm... while the heavier negatively charged ice
    particles and hailstones drop to the lower parts of the storm.
    This creates an enormous electrical charge differential.

    Also... the moving thunderstorm gathers another pool of
    positively charged particles along the ground that travel with
    the storm. As the differences in charges increase between the
    ground and the lower cloud... positively charged particles begin
    to rise up taller objects such as trees... powerlines and homes.

    Have you ever been in a storm and felt your hair standing up?
    Yes... the particles can move up on you!!! that is natures warning
    that you are at the wrong place and could become a lightning
    target.

    The negative charged area of the storm will send down an
    invisible charge to the ground called the "stepped leader".
    When it approaches the ground... it is attracted by all the
    positive charged particles forming a channel. At that point...
    you can see the electrical Transfer from the ground to the cloud
    within this channel as lightning.

    However... not all lightning forms in the negatively charged base
    of a thunderstorm. Some lightning originates in the positively
    charged upper levels of the storm and is called positive lightning.
    This lightning is particulary dangerous because it usually travels
    away from the rain core ahead or behind the storm at distances as
    far as 10 to 15 miles away from the storm. Thus... lightning can
    strike where no rain is falling!!!

    Thunder is the result of a lightning strike and is created when
    lightning heats up the air around it... up to 50,000 degrees and
    causes the air to rapidly expand and contract. The speed of light
    is much faster than the speed of sound. To estimate your distance
    from a lightning strike... count the number of seconds between
    witnessing a lightning Bolt and the sound of thunder... then Divide
    by 5. The end result will be the distance in miles you are from
    that particular lightning stroke.

    Here is a safety tip using what you have just Learned... the "30/30
    rule". At the beginning of a storm... when you see lightning...
    count the time until you hear thunder. If the time is 30 seconds
    or less or you Don not see lightning but hear thunder... seek safe
    shelter. Also... at the end of the storm... wait 30 minutes or more
    after hearing the last thunder before leaving the shelter.

    Additional lightning information can be found on the internet
    at NWS Lightning Safety

  2. #2
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    Good info about the formation of lightening and positive lightning.

    Three people just got hit on Sunday at Point Sebago, right down the road from me: Officials: 3 struck by lightning at Point Sebago Resort | Local News - WMTW Home

  3. #3
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    There was a t-storm far off in the distance on my commute home last night.

    As a kid, I saw someone indirectly struck by lightning. She happened to be leaning on a long chain link fence with a big tree at the other end that got zapped. That lightning strike came out of nowhere... no super dark clouds to speak of and barely a drizzle of rain.

  4. #4
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    Thanks for posting that. I could definitely stand to be more careful around bad weather.

  5. #5
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    This stuff has made my commute home really hard the last couple of days
    Save a tree & wipe your butt with an owl.
    Thank your local Sierra Club.

  6. #6
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    Sometimes 'seeking safe shelter' is getting home as fast as possible.

  7. #7
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    Just an honest question...assuming the ground is not yet wet, wouldn't the rubber tires of our bikes insulate us from a lightning strike?

  8. #8
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    Apparently not. It seems it's the metal cage and not the tires that protect you in a car, Here's an explanation, including National Weather Service info and other advice : snopes.com: Tires Protect Car from Lightning?

  9. #9
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    Quote Originally Posted by Gundam168 View Post
    Just an honest question...assuming the ground is not yet wet, wouldn't the rubber tires of our bikes insulate us from a lightning strike?
    Adding to what Mtbxplorer cited, a fork of lightning hit the house I was in and jumped from the aluminum window frame across the room to a grounded electrical outlet. That was some 20 feet, not to mention the distance the bolt did from the clouds and the main bolt hit the tree beside the house and exploded it. So what is an inch or four of bike tire to a force such as that?

  10. #10
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    Wundermap has a nice layer for showing lightning strikes along with the radar. Just check the lightning checkbox on the list of layers.There are different icons for strikes in last 5 minutes, older strikes and different kinds of lightning.

    For an example see
    WunderMap® | Interactive Weather Map and Radar | Weather Underground

  11. #11
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    If you’re riding out in the middle of nowhere without any cover (a.k.a. “BFE”) you’re pretty much screwed. I guess attaching a 20' tall lightning rod to one’s bike might help if it’s properly grounded, in addition to being insulated from the rider.
    QUOTE from MTBR.COM: You have given Brewtality too much Reputation in the last 24 hours, try again later.

  12. #12
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    Quote Originally Posted by Leopold Porkstacker View Post
    If you’re riding out in the middle of nowhere without any cover (a.k.a. “BFE”) you’re pretty much screwed. I guess attaching a 20' tall lightning rod to one’s bike might help if it’s properly grounded, in addition to being insulated from the rider.
    what would ACTUALLY work would be to enclose yourself in a Faraday Cage. This is why people are unhurt when lightning strikes their car or an airplane they're flying in. the metal of the car acts as a Faraday Cage. It has nothing to do with tires or other insulation.

  13. #13
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    Just add some aluminum hoops over the rider compartment which would support the soft top better:

    VelomobileUSA - Welcome

    Aluminum monoque construction drums a bit rolling along but should help with lightning. At a price.

  14. #14
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    Real time lightning strikes, with the sound but not the sizzle...

    Blitzortung.org ? lightning map USA, Canada ? thunderstorms and lightning strikes

  15. #15
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    Quote Originally Posted by Gundam168 View Post
    Just an honest question...assuming the ground is not yet wet, wouldn't the rubber tires of our bikes insulate us from a lightning strike?
    Lightning can jump thousands of feet from a cloud to the ground, it can most certainly jump from your wheel to the ground through the tire. It's a myth that the rubber from tires is what protects you. Lightning can strike a car, but the electricity travels through the metal frame of the car and not through you.

    At the Museum of Science in Boston there's a lightning show. They have a Van De Graaff generator. The person doing the show will stand in what's effectively a giant bird cage while it gets repeatedly struck by lightning to demonstrate this.

    Lightning! | Museum of Science, Boston

  16. #16
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    ^ Tires don't protect:

    https://www.youtube.com/watch?v=ACMlM1zyiWs

    Did a number on the plastics and electronics, too.

  17. #17
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