How RR Weather works

Four sources can describe one place differently

A nearby weather station records conditions at its own instrument site. That observation can be several miles away, at another elevation, or in a different exposure from the place you selected. RR Weather identifies it as a station observation and shows its time so you can judge how representative it may be.

NOAA surface analysis estimates conditions on a geographic grid. It can provide useful local context between stations, but it is still an analysis—not a thermometer located at your selected point. The app labels analyzed values separately for that reason.

National Weather Service forecasts describe expected future conditions. Forecast periods are not observations, and a forecast does not become a measurement merely because its valid time has arrived. RR Weather preserves that source distinction in its labels.

Radar detects energy returned from precipitation and other objects above the ground. It can indicate where precipitation may be occurring, but terrain, distance from the radar, beam height, and non-weather echoes can all affect what appears on the map.

What “What Matters” means

The Today view selects one timely point from the available forecast, observation, radar, and alert context. The goal is prioritization: highlight the change most likely to affect an ordinary decision without turning the page into a list of competing summaries.

This text is derived by RR Weather. It is not an official NOAA or NWS product, it does not create a warning, and it should not override an official alert. When the required evidence is missing or stale, the app should say so instead of inventing certainty.

National and local radar answer different questions

The national MRMS view combines radar and related inputs into a broad, frequently updated picture suited to regional context. The Local view uses individual NEXRAD Level II radar data for more detailed inspection near a selected radar station. Neither view is a photograph of rain at the ground.

A radar frame also represents a source time, not necessarily the current moment. Network delays, upstream availability, processing, and browser rendering can make a frame older than its display time. RR Weather retains timestamps and stale/error states so that a smooth animation does not imply fresher data than the source provides.

Official alerts stay official

Warning polygons and alert text come from official National Weather Service products. RR Weather may determine whether a selected point falls inside a polygon and may organize the result for display, but it does not issue, cancel, or change the alert.

Forecast commentary, radar-based arrival estimates, and other derived guidance use different language and visual treatment. That boundary is intentional: a useful estimate must not look like an official emergency instruction.

How to read freshness and uncertainty

• Check the source time before relying on a current-condition value or radar frame.
• Read “observation” as a nearby instrument report, not a measurement at your exact point.
• Read “analysis” or “estimate” as a gridded or derived value.
• Read “forecast” as an expectation that can change as new evidence arrives.
• Treat official alerts and local emergency instructions as the authority for protective action.

Data sources and independence

RR Weather uses public weather information from organizations that can include NOAA, the National Weather Service, NSSL, NESDIS, and AWS Open Data, plus map and place services such as OpenStreetMap. The app identifies sources where they are used. Source attribution does not imply that any provider endorses RR Weather.

The software and explanatory presentation are independently operated. For operational decisions, consult the original provider and an official warning channel as well as this interface.