This alert expired on 20 May 2026 at 23:30 UTC. It is kept here as a record.
It is the 6th strongest of the 266 detections recorded within 20 km of this point since 12 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 20 at 6:51PM EDT until May 20 at 7:30PM EDT by NWS Upton NY
An estimated 26,633,777 people live within 50 km of this point.
Nearby, since 12 March 2026
- July 18, 2026 · score 52 · 4.1 km
- March 12, 2026 · score 52 · 5.7 km
- July 28, 2026 · score 52 · 6.6 km
How we know
Confirmed by 4 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 89 % 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 | 89% |
| Coordinates | 40.4844, -74.1356 |
| Nearest City | Great Kills (7 km) |
| Population Exposed | 26.6M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-20T22:51:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.22f32da3df8422e9d5321beae588b335 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Hudson, NJ; Union, NJ; Kings, NY; Nassau, NY; Queens, NY; Richmond, NY; Middlesex, NJ; Monmouth, NJ; Ocean, NJ; Middlesex, NJ; Monmouth, NJ and 1 more areas |
| Headline | Severe Thunderstorm Warning issued May 20 at 6:51PM EDT until May 20 at 7:30PM EDT by NWS Upton NY |
| Expires | 2026-05-20T19:30:00-04:00 |
| SenderName | NWS Upton NY |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.22f32da3df8422e9d5321beae588b335e846aaa5.001.1","noaa_urn:oid:2.49.0.1.840.0.85fa7f41e84113ecb48ebf6ffa772625b9fc64e9.002.1","noaa_urn:oid:2.49.0.1.840.0.e5f2493d7a0684437d397c57bd1197a819d9f6ad.002.1","noaa_urn:oid:2.49.0.1.840.0.2514391dfa47852a43db0d380c500bbb11b1c684.001.1"] |
| Iem TypeSummary | H |
| Iem Magnitude | 0.75 |
| Iem Unit | Inch |
| Iem City | 1 N White Plains |
| Iem County | Westchester |
| Iem State | NY |
| Iem Wfo | OKX |
| MergedSources | [{"id":"iem_G_40.440_-74.200_1779316020000","source":"iem","severity":"low","severityValue":25,"timestamp":1779316020000,"latitude":40.44,"longitude":-74.2},{"id":"iem_D_40.390_-74.750_1779314220000","source":"iem","severity":"low","severityValue":25,"timestamp":1779314220000,"latitude":40.39,"longitude":-74.75},{"id":"iem_H_41.040_-73.760_1779309840000","source":"iem","severity":"low","severityValue":25,"timestamp":1779309840000,"latitude":41.04,"longitude":-73.76}] |
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.
Calamity.live data shows a weather event with CalamityScore 52/100, near Great Kills (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.