Number range CHAPTER November 19, 2004

Dear Snow Spotter,

Thank you for all your help last year! Your reports helped us, the
National Weather Service, have a successful year forecasting winter
storms. We had two significant events, one in January and the other in
March. Attached are the snowfall maps from these two events. These maps
were created from your measurements and show the fruits of your labor.

If you are new to the National Weather Service Wilmington, Ohio Snow
Spotter Network -- WELCOME!! We are thankful to have you as a volunteer.

The reason for having a Snow Spotter Network is to provide our
forecasters with near real-time snowfall information (i.e. ground
truth). As with Severe Weather, our forecasters can infer what is
currently going on or what will happen in the near future using various
tools (Radar, Satellite, Model Data, etc.). However, knowing how much
snow that has actually fallen ("ground truth") allows us to monitor the
progress of a storm and make critical decisions about Advisories and
Warnings for a particular winter storm.

The snowfall information collected will be used in several ways. First,
it will be used to help our forecasters make real-time decisions during
a winter storm. Second, it will be used to provide a summary of what
actually happened for all of our customers (State and Local officials,
media, and you). Finally, this ground truth information will be used to
help our forecasters evaluate how well their forecasts turned out, which
will help improve the forecast of future winter storms. **This is all
thanks to you!!!**

As a snow spotter we would like you to **report in real-time** the
following information:

+---------------------------------------+------------------------------+
| ## What to Report                     | #                            |
|                                       | [When to Report]{.underline} |
+---------------------------------------+------------------------------+
| -   **1\"** or more of snow per hour  | -   Anytime                  |
|                                       |                              |
| -   **1\"** or more of snow during    | -   Preferably between 5-8   |
|     the past 24 hours                 |     am/pm                    |
|                                       |                              |
| -   **Total Snow Depth**              | -   Preferably between 5-8   |
|                                       |     am/pm                    |
| -   **When you first measure 2"\...4" |                              |
|     and 6"**                          | -   Anytime                  |
|                                       |                              |
| -   **Any freezing rain/drizzle**     | -   Anytime                  |
|                                       |                              |
| -   **Thunder/lightning** associated  | -   Anytime                  |
|     with snow/sleet/freezing rain     |                              |
+---------------------------------------+------------------------------+

Our toll free unlisted number is 1-800-899-2748. On occasion, we may
give you a call during a snow event. We will only call during the times
you approved of on your Severe Weather Spotter application.

**Below are some tips for measuring snow:**

Measuring snow is a rough art and can be very subjective. A lot depends
on frequency and location of your measurement. You want a cold flat
surface that is somewhat protected from the wind, but not so protected
that snowfall measurements will be inaccurate.

-   **Surface**:

    -   First choose a convenient spot away from the obstacles such as
        house, garage, shed, fence, large bushes and trees. Ideally
        about 10-12 feet from a 6 foot fence. These objects aid in
        pilling up the snow in a drift. This spot will usually be in the
        middle of your back or front yard.

    -   Ideally a snow board (A snowboard is simply a piece of plywood
        cut in about a 2 ft square and painted white.), an outdoor
        table, or a deck are the best measuring surfaces. If you use a
        snowboard on the ground, then a flag or something similar to
        mark it with is ideal for snow measuring.

        -   Pavement is OK if it's cold (below 32 F), but should not be
            used under milder conditions due to melting.

        -   Grass is too uneven\...especially in the Fall and after
            Greenup in the spring. Grass may be used in the middle of
            winter, if it is dead and not puffy.

        -   Bare ground is OK. Do not mistake an ice layer or crusted
            snow as the "ground".

        -   Picnic table and autos are fine if winds are light.

    -   If possible, clean off the surface you are measuring off of for
        your next measurement. If measuring on a surface that already
        has a covering of snow, then subtract the old snow from the new

-   **Wind/Drifting:** If drifting is a problem, take several
    measurements and average them. Bare ground will give you a zero
    reading. Do not include the largest drifts.

-   **Frequency:** As for frequency\...do not measure [more]{.underline}
    than once an hour. Hourly measurements will be extremely helpful
    when snowfall rates are exceptional (1\" or more per hour). In
    general, once every several hours (3 to 6) is preferable (unless the
    snow is melting).

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-   **Total snowfall:** Report to the nearest tenth of an inch.

-   **Snow Depth:** Report to the nearest whole inch. Roundup at 0.5
    inches.

-   *The optimal conditions for measuring snow are to find a piece of
    wood (wooden picnic table or piece of ply-wood) in an open area
    where snow will fall unhindered and yet not drift from blustery
    winds. After measuring the snow clean off the piece of wood for your
    next reading.*

-   Below is a figure that will hopefully provide some insight to the
    points mentioned above:

![](media/image1.wmf){width="6.519444444444445in"
height="4.971527777777778in"}

This upcoming winter season we will be making a concerted effort to
place snowfall maps on the web soon after the event. The maps will be
located near the top of our front page at
[www.erh.noaa.gov/iln/spotter.htm](http://www.erh.noaa.gov/iln/spotter.htm)
. Additional Snow Spotter information will be added through the winter
season at
[www.erh.noaa.gov/iln/spotter.htm](http://www.erh.noaa.gov/iln/spotter.htm)
.

Thanks again for volunteering! Your time and effort is greatly
appreciated. Feel free to call me at 1-800-899-2748 if you have any
questions.

Mary Jo Parker

Warning Coordination Meteorologist

National Weather Service

Wilmington, Ohio

![](media/image2.jpeg){width="6.497222222222222in"
height="6.247916666666667in"}

January 25, 2004 Snow and Ice storm

![](media/image3.jpeg){width="6.497222222222222in"
height="6.247916666666667in"}

March 16, 2004 Snow Storm