How to measure hail. I would like to hear from someone from NOAA.

Discussion in 'Advanced weather & chasing' started by beaudodson, Aug 10, 2017.

  1. beaudodson

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    Hello

    We had a large hail event last winter that produced very large hail. The problem was that the hail was spiked. I was hoping I could find photos of it, but so far I have not been able to pull them up.

    I was taught that you measure hail from spike to spike. Is this correct? Can someone show where the NWS considers that the correct way to measure hail?

    There has been some discussion on Storm Track about the ideal way of measuring hail. In an ideal world you would measure it be size and weight. Spikes don't always add that much weight to the stone.

    Nevertheless, that isn't the way it works (at least today).

    What is the official way of measuring hail.

    If a stone is half dollar in size (core) but has two inch spikes all the way around, then how do you measure that stone.

    Attached is a photo from the Goodland, NWS from earlier today

    2017-08-10_15-05-38.png
     
  2. beaudodson

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    Here are the stones in question

    2017-08-10_15-44-47.png 2017-08-10_15-44-31.png 2017-08-10_15-45-29.png
     
  3. Jeff Duda

    Jeff Duda Resident meteorological expert
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    When it really comes down to it, It really doesn't matter. Give your best guess.

    Scientific studies based on observed severe hail reports strongly acknowledge the inconsistencies and errors in Storm Data/observed large hail reports. In my personal scientific opinion, the aspect of hail that truly represents its size is mass and volume. Size is arbitrary due to oblateness and spikiness, but its also the easiest/simplest/cheapest to measure and in many cases, the maximum length along the major axis is comfortably proportional to mass and volume.
     
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  4. beaudodson

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  5. James Wilson

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    I like to take a photo of the hail with a golf ball, baseball etc to get a better idea if I have the time to do so. But that is more to give credit to the report when it comes down to it most people guess the size based on experience seeing it.
     
  6. beaudodson

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    I ended up producing this graphic.
     

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  7. Todd Lemery

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    As a quick follow up to the previous post, after you have measured the hail, double the measurement when you tell anybody about it. After a year, it’s then appropriate to triple the measurement. This also works with fish you’ve caught!
     
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