This alert expired on 11 June 2026 at 22:45 UTC. It is kept here as a record.
It is the 7th strongest of the 24 detections recorded within 20 km of this point since 17 March 2026. The last comparable one was on 21 May 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 11 at 5:40PM EDT until June 11 at 6:45PM EDT by NWS Upton NY
An estimated 1,972,705 people live within 50 km of this point.
Nearby, since 17 March 2026
- June 11, 2026 · score 46 · 4.9 km
- July 18, 2026 · score 52 · 7.9 km
- June 12, 2026 · score 46 · 9.9 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 46 out of 100, at 80 % 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) | 46 / 100 |
| Our confidence | 80% |
| Coordinates | 40.8129, -73.0318 |
| Nearest City | Holtsville (2 km) |
| Population Exposed | 2.0M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-11T21:40:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.f6d8862c053e1edd2db5d7637623be6b2f543645.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Suffolk, NY |
| Headline | Severe Thunderstorm Warning issued June 11 at 5:40PM EDT until June 11 at 6:45PM EDT by NWS Upton NY |
| Expires | 2026-06-11T18:45:00-04:00 |
| SenderName | NWS Upton NY |
| HasExactCoords | true |
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 Holtsville?
Calamity.live data shows a weather event with CalamityScore 46/100, near Holtsville (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 187 scientific monitoring sources.