NORMAN — The National Severe Storms Laboratory in Norman is inviting people within a 90-mile radius of Norman to participate in the Winter Precipitation Identification Near the Ground project. Volunteer-submitted readings from the project will help researchers improve computer programs and radar techniques, according to a statement from the National Oceanic and Atmospheric Administration Weather Partners in Norman. Winter precipitation is difficult to forecast because it may melt or refreeze very near the ground. Because radar cannot see close to the ground, scientists will use public observations of what is actually happening at the surface to compare with radar detections. This is the first time volunteer observations will be compared with data from two radars during 2010 operations. The third-year program provides an opportunity for classrooms, families and lay scientists in the area to be part of weather research happening in their own backyards. Volunteers should visit www.nssl.noaa.gov/projects/winter/ and click on "I Want to Volunteer!” The form will request the date, time, location and precipitation type. There is no minimum requirement for reports.