IEM Daily Feature
Thursday, 28 September 2023

Source of Hail Reports

Posted: 28 Sep 2023 05:30 AM

While RADAR provides NWS Meteorologists with high spatial and temporal resolution data of storms, it misses what's happening at the ground surface due to beam tilt and curvature of the Earth (sorry flat-earthers). RADAR also can not explicitly determine hail size that is reaching the ground, so the NWS is heavily reliant on folks to report to them hail size received. When the NWS receives such a report, they often disseminate that observation in the form of a "Local Storm Report" (LSR). The LSR product contains a classification of whom the report is sourced from. The featured chart presents a yearly accounting of these source classifications for hail reports nationwide. The sources are ranked each year for the number of reports received with a line connecting each source type between the years. The top two most frequent sources have not changed over the past eighteen years, but their ordering has. The reason is likely to do with NWS software changes for how LSRs are created with "public" being the current default source and also an increase in social media / NWSChat reports that get lumped into that classification as well. The actual "social media" classification is not extensively utilized, so most reports from there get lumped into public. Anyway, the IEM offers a shapefile download of these LSR reports.

Good = 10
Bad = 0

Tags:   lsr   hail