A Local Storm Report (LSR) is a short text product issued by a National Weather Service (NWS) forecast office that documents a specific significant weather event, including hail, damaging wind, flooding, or a tornado.
What the report contains
Each LSR entry lists the event type, the time it occurred, the location by county and reference point, the reporting source, and a brief remark. Common event types include tornado, funnel cloud, hail with a measured size, thunderstorm wind gust or damage, flash flood, and heavy snow. The remark field is where the office captures detail, such as damage descriptions, measurement instruments used, or track information.
The information behind an LSR comes from many sources: trained SKYWARN spotters, law enforcement, emergency management, cooperative observers, media, mesonet stations, and the public. The office cross-checks reports against radar and other data before issuing them, but the product is still considered preliminary.
How forecasters and partners use it
During an event, LSRs give the warning forecaster near-real-time confirmation that a warned storm is producing on the ground. That feedback helps decide whether to upgrade a warning, extend it downstream, or issue an impact-based warning tag. Broadcast partners and emergency managers rely on the same product to communicate hazards to the public quickly.
After the event, LSRs feed the Storm Data record. The NWS directive that governs Storm Data (NWSI 10-1605) sets the standards for how events are classified, timed, and located. This is why the format and thresholds behind an LSR are consistent from office to office.
Important limits
An LSR is not a final verification. Hail sizes get updated as better measurements arrive, wind reports are refined once damage is surveyed, and tornado paths are often adjusted after a ground survey. Do not treat a first-issued LSR as the last word on the event.
Coverage is also uneven. A tornado in open country with few observers can go unreported until a survey the next day, and rural damaging wind is chronically underreported compared to hail. The absence of an LSR does not prove absence of a hazard.