Right now
The most recent data we hold from NOAA arrived 3 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 4th strongest of the 89 detections recorded within 20 km of this point since 16 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 19 at 6:05PM EDT until May 19 at 6:15PM EDT by NWS Boston/Norton MA
Urban PEI: 4,956,680 within a heuristic 50 km radius; not unique people.
Nearby, since 16 March 2026
- August 8, 2026 · score 52 · 3.1 km
- June 30, 2026 · score 52 · 4.7 km
- June 18, 2026 · score 64 · 4.7 km
How we know
3 recorded sources include NOAA; independence is not established by this count.
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 | 0.91/1 |
| Coordinates | 42.2417, -71.5061 |
| Nearest City | Ashland (4 km) |
| Urban exposure index (PEI) | 5.0M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-19T22:05:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.3a2c9bd8c2b666d39a38e5f123375ca5 |
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: 2026-05-19T22:05:00.000Z.
First archived: 2026-05-19T22:12:13.703Z. 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 | Hampden, MA; Worcester, MA; Middlesex, MA; Norfolk, MA; Plymouth, MA; Suffolk, MA; Middlesex, MA; Norfolk, MA; Worcester, MA and 1 more areas |
| Headline | Severe Thunderstorm Warning issued May 19 at 6:05PM 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 | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.3a2c9bd8c2b666d39a38e5f123375ca551b688c6.001.1","noaa_urn:oid:2.49.0.1.840.0.9b2a0ee3c3c69d31f9a6925ac381b24e7d49d6a8.001.1","noaa_urn:oid:2.49.0.1.840.0.1ea24d30ea03339987ea1ca8cf318312cdca881f.001.1","noaa_urn:oid:2.49.0.1.840.0.383092258aac42ad05ce33a8ea509921ff4a325e.001.1"] |
| Google News RssFeed | weather |
| Google News SourceName | NBC Boston |
| MergedSources | [{"id":"gnews_weather_494224_159","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779207960000,"latitude":42.36,"longitude":-71.06},{"id":"gnews_weather_494224_165","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779209674000,"latitude":42.36,"longitude":-71.06}] |
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.
Want to know when something happens near Ashland?