Right now
The most recent data we hold from NOAA arrived 2 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 19 May 2026 at 22:15 UTC. It is kept here as a record.
It is the 3rd strongest of the 67 detections recorded within 20 km of this point since 16 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 5:15PM EDT until May 19 at 6:15PM EDT by NWS Boston/Norton MA
Urban PEI: 1,033,833 within a heuristic 50 km radius; not unique people.
Nearby, since 16 March 2026
- July 3, 2026 · score 52 · 6.8 km
- May 19, 2026 · score 52 · 16.9 km
- May 19, 2026 · score 52 · 17.2 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.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
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 |
| Legacy data-support index | 0.80/1 |
| Coordinates | 42.1476, -72.0956 |
| Nearest City | Southbridge (9 km) |
| Urban exposure index (PEI) | 1.0M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-19T21:15:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.0fdeaee4c6f1d52b7cbffc08f2a8cbf6 |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-05-19T21:15:00.000Z.
First archived: 2026-05-19T21:20:46.081Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Franklin, MA; Hampden, MA; Hampshire, MA; Worcester, MA; Hartford, CT; Middlesex, MA; Norfolk, MA; Worcester, MA |
| Headline | Severe Thunderstorm Warning issued May 19 at 5:15PM EDT until May 19 at 6:15PM EDT by NWS Boston/Norton MA |
| Expires | 2026-05-19T18:15:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.0fdeaee4c6f1d52b7cbffc08f2a8cbf65058b777.001.1","noaa_urn:oid:2.49.0.1.840.0.28b5d1822306385a511fc0bb13dc7671333cd66f.001.1","noaa_urn:oid:2.49.0.1.840.0.b744fb453237a86f22148d92d860cb21bd19fb6d.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 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.
Review the area, threshold and delivery channel in your account.
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