Guides for PDR professionals
Three documented hail cases from Europe and the USA
What does HailSignal detect, and what does the evidence establish? Three specific cases illustrate radar detection and an actual US alert. Evidence reviewed in September 2026.
Sizzano · Italy · 7 August 2026
A historical radar review on 14 September reconstructed a spatially matching C2 hail track from 37 complete radar pairs. The local grid estimate reached 54 mm. Millevigne reports hail damage to local vineyards. The size is a radar estimate; delivery timing to customers at the time was not established.
Seuzach and Neftenbach · Switzerland · 28 August 2026
Zurich cantonal police document hail and damage in both communities. The historical review on 14 September placed both local grid points inside detected C2 cells: Seuzach at 08:05–08:10 UTC and Neftenbach at 08:00–08:05 UTC. Local radar maxima were 47 and 31 mm respectively. No co-located ground size measurement or customer delivery time was established.
Alta · Illinois, USA · 16 September 2026
An actual C3 alert was accepted by the delivery provider at 02:38:32 UTC: 1 minute 31 seconds after the ground report was stored and 6.2 seconds after the event version was created. The latest radar timestamp was then 19.9 minutes old. Source: the internal weekly review of 17 September. This measures provider acceptance, not phone receipt or elapsed time since hail began.
How these examples were selected
Two separate European storms with external ground evidence and one actual US dispatch. The European results are retrospective calculations using archived radar data. This small, selected set is not an overall accuracy rate. Linked reports support the weather event, not an endorsement of HailSignal.