With a major winter storm expected to impact a large part of the Midwest including Illinois over the next few days, snowfall reports will be greatly appreciated. Here are a few reminders for our volunteer reporting networks.
Coop observers are reminded to report observations of precip (melted water equivalent of new snowfall), snowfall, and snow depth every day. Daily reports allow us to compile listings and create maps of snowfall totals for snowstorms that span periods exceeding 24 hours.
Precipitation - remember that the WxCoder data entry box for Precipitation (or prompt in IV-ROCS) includes rainfall, or in the case of snow, the melted water equivalent of the snow that collected in the standard rain gauge can. It is important to melt down the snow that has collected in the gauge. Precipitation (rainfall or melted snow) is measured to the hundredth of an inch (e.g. 1.24 inches).
Snowfall - snow boards are useful for measuring the amount of new snow that has fallen in the last 24 hours. However, when strong winds create considerable blowing and drifting, the amount of snow on the snowboard will not be representative. In those cases, take several readings around your location (not in snow drifts, or in artificial snow piles as a result of plowing) and average them to determine the new snowfall. Also, remember that new snowfall is reported in INCHES and TENTHS (such as 9.7").
Snow Depth - snow depth represents the total of all snow on the ground at observation time, both old and new snow. Take several measurements around your yard (not in snow drifts, or in artificial snow piles as a result of plowing) to determine an average snow depth. NWS Cooperative observers report snow depth to the nearest whole inch (7 inches).
More info on NWS snow measurement guidelines can be found here . . .
In addition to daily reports, supplemental Significant Weather Reports are greatly appreciated from SWOP and CoCoRaHs observers.
E-spotter for SWOPs.
Snow reports are also welcome from trained spotters and the general public using the following links:
E-spotter for trained spotters
For public reports, please call the weather forecast office at 217-732-3089.