This alert expired on 17 March 2026 at 22:15 UTC. It is kept here as a record.
It is the 2nd strongest of the 90 detections recorded within 20 km of this point since 16 March 2026. 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 6:03AM EDT until March 18 at 12:18AM EDT by NWS Gray ME
An estimated 3,941,956 people live within 50 km of this point.
Nearby, since 16 March 2026
- August 3, 2026 · score 46 · 3.9 km
- May 19, 2026 · score 52 · 7.3 km
- June 18, 2026 · score 52 · 11.5 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 90 % 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 | 90% |
| Coordinates | 42.4074, -71.6438 |
| Nearest City | Marlborough (10 km) |
| Population Exposed | 3.9M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-17T14:40:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flood Warning_noaa_urn:oid:2.49.0.1.840.0.98a8cd9351fbb6b4773802543b85da65 |
Score Breakdown
Technical Details
| Event | Flood Warning |
| Urgency | Expected |
| Certainty | Likely |
| AreaDesc | Cumberland, ME; Oxford, ME; Carroll, NH; Grafton, NH; Middlesex, MA and 4 more areas |
| Headline | Flood Warning issued March 17 at 6:03AM EDT until March 18 at 12:18AM EDT by NWS Gray ME |
| Expires | 2026-03-17T18:15:00-04:00 |
| SenderName | NWS Gray ME |
| HasExactCoords | true |
| MergedCount | 7 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.98a8cd9351fbb6b4773802543b85da6572fcb074.001.1","noaa_urn:oid:2.49.0.1.840.0.50f4e35d8ebf40d50cde931e6c24ad9a99000f5f.001.1","noaa_urn:oid:2.49.0.1.840.0.d87305d43a25a97333f6a1ea2ae3f826d5f28869.003.1","noaa_urn:oid:2.49.0.1.840.0.d87305d43a25a97333f6a1ea2ae3f826d5f28869.001.1","noaa_urn:oid:2.49.0.1.840.0.32e231489aa0bee43e0a26beb56bbabc1607276b.001.1","noaa_urn:oid:2.49.0.1.840.0.d87305d43a25a97333f6a1ea2ae3f826d5f28869.004.1","noaa_urn:oid:2.49.0.1.840.0.d87305d43a25a97333f6a1ea2ae3f826d5f28869.002.1"] |
| Iem TypeSummary | O |
| Iem City | 2 NW Milford |
| Iem County | Hillsborough |
| Iem State | NH |
| Iem Wfo | GYX |
| Iem Remark | North River Road closed due to downed tree. |
| MergedSources | [{"id":"iem_O_42.860_-71.670_1773739140000","source":"iem","severity":"low","severityValue":25,"timestamp":1773739140000,"latitude":42.86,"longitude":-71.67},{"id":"iem_O_42.850_-71.690_1773739080000","source":"iem","severity":"low","severityValue":25,"timestamp":1773739080000,"latitude":42.85,"longitude":-71.69}] |
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 Marlborough?
Calamity.live data shows a weather event with CalamityScore 52/100, near Marlborough (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 187 scientific monitoring sources.