HailMapr field guide
Replay the radar behind the storm
See how a storm moved through your working area instead of relying on a single screenshot. HailMapr's radar overlay plays archived reflectivity alongside the other available storm-map layers.
Open radar replay in a storm map
Open a map you can access, choose Layers and enable Radar replay. Radar is off by default, so normal map loading does not wait for replay imagery. The compact playback bar contains Play, a timeline, the current scan timestamp and playback speed.
Expand settings to choose the From and To times and adjust opacity. Selecting either endpoint automatically adjusts the other to a two-hour window, bounded by the available storm period, then loads that window. Collapse settings to give the map more room.
Two-hour windows and five-minute frames
A two-hour selection uses up to 25 five-minute frames, including both endpoints, rather than loading an entire long daily storm window. The displayed replay timestamp uses Central Time, with CST or CDT according to the date.
Playback preloads upcoming imagery. At closer zoom levels, the viewer requests sharper detail for the area in view and holds the current scan until the next required sharp scan is ready. This can pause progression on a slower connection; it avoids advancing to a blurry replacement just to maintain a timer.
Radar colors are not hail-size measurements
Reflectivity shows the strength of radar returns from precipitation. Intense colors can be associated with heavy rain, hail or a mixture. They should not be read as a direct measurement of hail diameter at a roof.
HailMapr's hail-core and Ground Impact layers are different products. Compare them with the radar and available reports, but do not expect their centers or outlines to match perfectly. Timestamp differences, scan resolution and the difference between reflectivity and hail-size estimation can all affect the appearance.
Zoom, compare and stay within your coverage
Zoom to your working neighborhood and adjust radar opacity to keep roads and door pins readable. State subscriptions use the same subscribed-state boundary as the other restricted map layers. National coverage is governed by the corresponding plan. Adding a rep does not expand the owner's map coverage.
Newly viewed areas may need additional imagery. Cached scans can reduce repeated downloads, but replay still uses bandwidth and memory while it is enabled. Turn the layer off in Layers when you no longer need it.
Understand the source and available history
The radar imagery used by this overlay is supplied through the Iowa Environmental Mesonet radar archive. Availability and detail depend on the archived product and time. Missing scans are not evidence of clear weather, and replay is not a substitute for current official warnings.
Read how HailMapr distinguishes radar from hail estimates, explore an available sample map, or use property storm history when investigating an earlier date.