A Local Storm Report (LSR) is transmitted by the National Weather Service (NWS) when it receives significant information from storm spotters, such as amateur radio operators, storm chasers, law enforcement officials, civil defense (now emergency management) personnel, firefighters, EMTs or public citizens, about severe weather conditions in their warning responsibility area (County Warning Area or CWA). Those reports are received by local National Weather Service offices (WFOs), and they can be used to issue Severe Thunderstorm Warnings, Tornado Warnings, and other weather warnings/bulletins, in addition to the LSR.
The Storm Prediction Center, working with the NWS WFOs, collects these reports for its own database, and it also works with the National Climatic Data Center, which eventually stores the reports in the official record, which is called Storm Data.
Example
The following is an example of a stand-alone LSR that has one individual report from a SKYWARN spotter:
NWUS53 KGID 172339 LSRGID PRELIMINARY LOCAL STORM REPORT NATIONAL WEATHER SERVICE HASTINGS NE 639 PM CDT THU JUN 17 2010 ..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. 0636 PM HAIL 2 SSW KIRWIN 39.64N 99.14W 06/17/2010 E0.75 INCH PHILLIPS KS TRAINED SPOTTER DIME SIZE HAIL AT SCOUT RESERVATION && $$Summary LSRs, which can have an extensive listing of individual reports, are also often issued by NWS WFOs after a weather event has ended in order to inform the public and news media outlets of the breadth of severe weather across a WFO's CWA.