Special Marine Warning issued July 4 at 7:40PM EDT until July 4 at 7:45PM EDT by NWS Boston/Norton MA
Geographic Context
This weather event occurred near Johnston (approximately 9 km away) in United States, an area that experiences a range of natural hazards. An estimated 1.4M people live within 50 km of the event location, placing this in the "significant" population impact tier.
Event Assessment
This event is a weather event classified as medium severity. Calamity.live has classified it as "medium" severity with a severity value of 50. The computed Calamity Score is 52 out of 100, reflecting a moderate-impact event. The primary scoring components are: population (100), historical (80), intensity (35). Data for this event was sourced from noaa, one of the 196 scientific monitoring sources aggregated by Calamity.live.
Regional Monitoring Context
United States has a documented history of weather events. Monitoring for weather events in the region relies on a combination of ground-based sensors, satellite remote sensing, and official reporting from national agencies. The frequency and severity of such events are tracked over time to support risk assessment and emergency preparedness.
Event Data
| Type | Weather |
| Severity | medium |
| Severity Value | 50 |
| Calamity Score | 52 / 100 |
| Confidence | 79% |
| Coordinates | 41.8225, -71.6170 |
| Nearest City | Johnston (9 km) |
| Population Exposed | 1.4M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-04T23:40:00.000Z |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Boston Harbor; Massachusetts Bay and Ipswich Bay; Long Island Sound East of New Haven CT/Port Jefferson NY to the Mouth of the Connecticut River; Long Island Sound East of the Mouth of the Connecticut River |
| Headline | Special Marine Warning issued July 4 at 7:40PM EDT until July 4 at 7:45PM EDT by NWS Boston/Norton MA |
| Expires | 2026-07-04T19:50:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.347c6f516ae50e55f55f8a174acf15bfe0550570.001.1","noaa_urn:oid:2.49.0.1.840.0.a6010ff26f6d909642df2e16863d20cd2dc3ea8b.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.
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 Johnston (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 196 scientific monitoring sources.