This alert expired on 18 March 2026 at 09:00 UTC. It is kept here as a record.
No stronger detection stands among the 53 recorded within 20 km of this point since 17 March 2026 — 6 others scored the same. Another comparable one was recorded here earlier the same day. 4 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flood Warning issued March 17 at 12:07PM EDT until March 19 at 2:00AM EDT by NWS Boston/Norton MA
An estimated 1,047,399 people live within 50 km of this point.
Nearby, since 17 March 2026
- June 26, 2026 · score 52 · 10.4 km
- July 16, 2026 · score 52 · 11.1 km
- June 18, 2026 · score 48 · 11.5 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 | 42.9796, -71.3189 |
| Nearest City | Derry Village (10 km) |
| Population Exposed | 1.0M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-17T18:00:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flood Warning_noaa_urn:oid:2.49.0.1.840.0.faea710527689872ac2c740df42af5ec |
Score Breakdown
Technical Details
| Event | Flood Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Bristol, MA; Plymouth, MA; Kent, RI; Providence, RI; Belknap, NH; Merrimack, NH and 2 more areas |
| Headline | Flood Warning issued March 17 at 12:07PM EDT until March 19 at 2:00AM EDT by NWS Boston/Norton MA |
| Expires | 2026-03-18T05:00:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.faea710527689872ac2c740df42af5ec285b513a.003.1","noaa_urn:oid:2.49.0.1.840.0.faea710527689872ac2c740df42af5ec285b513a.004.1","noaa_urn:oid:2.49.0.1.840.0.0af872af59fab259a2ce51d4e0911625b9183d0a.001.1","noaa_urn:oid:2.49.0.1.840.0.98a8cd9351fbb6b4773802543b85da6572fcb074.001.1","noaa_urn:oid:2.49.0.1.840.0.50f4e35d8ebf40d50cde931e6c24ad9a99000f5f.001.1"] |
Safety Information
During flooding: never walk, swim, or drive through floodwaters. Six inches of moving water can knock you down, and one foot of water can sweep away a vehicle. Move to higher ground if waters rise. After flooding, avoid contact with floodwater which may contain sewage, chemicals, or debris. Follow local emergency service guidance.
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 Derry Village?
Calamity.live data shows a weather event with CalamityScore 52/100, near Derry Village (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.