Right now
The most recent data we hold from NOAA arrived 6 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 20 May 2026 at 01:30 UTC. It is kept here as a record.
It is the 3rd strongest of the 84 detections recorded within 20 km of this point since 13 March 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 19 at 8:59PM EDT until May 19 at 9:30PM EDT by NWS Wilmington OH
An estimated 1,290,845 people live within 50 km of this point.
Nearby, since 13 March 2026
- May 20, 2026 · score 52 · 0.9 km
- August 16, 2026 · score 52 · 7.5 km
- March 13, 2026 · score 52 · 9.7 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.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 52 / 100 |
| Our confidence | 86% |
| Coordinates | 39.9634, -83.1233 |
| Nearest City | Upper Arlington (6 km) |
| Population Exposed | 1.3M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-20T00:59:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.a0e8ccda0471c44f88eadf943b3e9b1a |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Fayette, OH; Franklin, OH; Madison, OH; Pickaway, OH; Delaware, OH; Franklin, OH; Licking, OH; Madison, OH; Union, OH |
| Headline | Severe Thunderstorm Warning issued May 19 at 8:59PM EDT until May 19 at 9:30PM EDT by NWS Wilmington OH |
| Expires | 2026-05-19T21:30:00-04:00 |
| SenderName | NWS Wilmington OH |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.a0e8ccda0471c44f88eadf943b3e9b1ac2daff3b.001.1","noaa_urn:oid:2.49.0.1.840.0.16fdca84a200f13d26c9674b77e21090bcb91b2d.001.1"] |
| Iem TypeSummary | D |
| Iem City | Choctaw Lake |
| Iem County | Madison |
| Iem State | OH |
| Iem Wfo | ILN |
| Iem Remark | Tree limbs down and minor shed damage. Time estimated from RADAR. |
| MergedSources | [{"id":"iem_D_39.960_-83.490_1779237900000","source":"iem","severity":"low","severityValue":25,"timestamp":1779237900000,"latitude":39.96,"longitude":-83.49}] |
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 8 March 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 Upper Arlington?
Calamity.live data shows a weather event with CalamityScore 52/100, near Upper Arlington (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.