This alert expired on 20 May 2026 at 02:00 UTC. It is kept here as a record.
It is the 4th strongest of the 65 detections recorded within 20 km of this point since 15 March 2026. Another comparable one was recorded here earlier the same day. 5 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 19 at 9:50PM EDT until May 19 at 10:00PM EDT by NWS Wilmington OH
An estimated 1,264,536 people live within 50 km of this point.
Nearby, since 15 March 2026
- May 27, 2026 · score 76 · 8.6 km
- August 11, 2026 · score 52 · 11.6 km
- July 7, 2026 · score 43 · 14.1 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 86 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 52 / 100 |
| Our confidence | 86% |
| Coordinates | 39.8520, -82.5288 |
| Nearest City | Lancaster (17 km) |
| Population Exposed | 1.3M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-20T01:50:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.6bc5d882d8e203e09cf9299694e38f4f |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Fairfield, OH; Franklin, OH; Licking, OH; Pickaway, OH; Perry, OH |
| Headline | Severe Thunderstorm Warning issued May 19 at 9:50PM EDT until May 19 at 10:00PM EDT by NWS Wilmington OH |
| Expires | 2026-05-19T22:00:00-04:00 |
| SenderName | NWS Wilmington OH |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.6bc5d882d8e203e09cf9299694e38f4f31f22c92.001.1","noaa_urn:oid:2.49.0.1.840.0.7bef9ba51fc6a0bc9315492990be560b88293ed8.001.1"] |
| Iem TypeSummary | D |
| Iem City | 3 SE Chesterhill |
| Iem County | Washington |
| Iem State | OH |
| Iem Wfo | RLX |
| Iem Remark | Tree limb down on house. Another tree down as well. |
| MergedSources | [{"id":"iem_D_39.460_-81.820_1779228240000","source":"iem","severity":"low","severityValue":25,"timestamp":1779228240000,"latitude":39.46,"longitude":-81.82}] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 10 February 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Want to know when something happens near Lancaster?
Calamity.live data shows a weather event with CalamityScore 52/100, near Lancaster (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 187 scientific monitoring sources.