This alert expired on 19 May 2026 at 22:00 UTC. It is kept here as a record.
It is the 2nd strongest of the 59 detections recorded within 20 km of this point since 17 March 2026. The last comparable one was on 17 March 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 19 at 5:02PM EDT until May 19 at 6:00PM EDT by NWS Boston/Norton MA
An estimated 1,370,964 people live within 50 km of this point.
Nearby, since 17 March 2026
- August 8, 2026 · score 52 · 8.6 km
- May 19, 2026 · score 52 · 9.7 km
- May 19, 2026 · score 52 · 10.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 out of 100, at 79 % 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 | 79% |
| Coordinates | 42.0440, -72.2511 |
| Nearest City | Palmer (14 km) |
| Population Exposed | 1.4M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-19T21:02:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.b744fb453237a86f22148d92d860cb21 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Middlesex, MA; Norfolk, MA; Worcester, MA; Hartford, CT |
| Headline | Severe Thunderstorm Warning issued May 19 at 5:02PM EDT until May 19 at 6:00PM EDT by NWS Boston/Norton MA |
| Expires | 2026-05-19T18:00:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.b744fb453237a86f22148d92d860cb21bd19fb6d.001.1","noaa_urn:oid:2.49.0.1.840.0.a86a4cb81af1b589873dc9eecb338d28d6d70bb1.001.1"] |
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 Palmer (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.