Verified storm · closed
1.2–2.8" hail crossed Pennington County, SD — August 19, 2026
Measured against the NOAA MRMS national radar feed on its 2-minute cycle — a verified event, not a forecast.
Storm stats
| County | Pennington County, SD |
|---|---|
| Max hail (MESH) | 2.8" |
| Mean hail (MESH) | 1.2" |
| Swath area | 84 mi² (217 km²) |
| Radar cells (~1 km grid) | 244 |
| First radar detection | 2026-08-19 00:54 UTC |
| Last radar detection | 2026-08-19 03:22 UTC |
| Verified | 2026-08-19 00:56 UTC |
| Swath centroid | 44.1405, -103.4543 |
| Storm ID | sw_f84fdef2 |
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Pennington County, SD — verified storm record
Swath has 88 radar-verified hail storms on record for Pennington County, SD going back to July 2025, the largest measuring 5.74″. Every one was measured against NOAA MRMS radar — not estimated, and not a forecast.