Right now
The most recent data we hold from NOAA arrived 23 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 18 May 2026 at 21:15 UTC. It is kept here as a record.
No stronger detection stands among the 29 recorded within 20 km of this point since 16 March 2026 — 14 others scored the same. The last comparable one was on 16 March 2026.
What the source measured
NOAA reported: Special Marine Warning issued May 18 at 3:42PM EDT until May 18 at 5:15PM EDT by NWS Detroit/Pontiac MI
Nearby, since 16 March 2026
- July 18, 2026 · score 22 · 19.0 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 22 out of 100, at 64 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 22 / 100 |
| Our confidence | 64% |
| Coordinates | 44.6881, -83.1403 |
| Nearest City | Bay City (136 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-18T19:42:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.8dc641cc039726fcd16d58f69ff6f153 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Outer Saginaw Bay SW of Alabaster to Port Austin MI to Inner Saginaw Bay; Port Austin to Harbor Beach MI; Lake Huron from Port Austin to Harbor Beach 5NM Off Shore to the US/Canadian border; 5NM East of Mackinac Bridge to Presque Isle Light MI including Bois Blanc Island; Presque Isle Light to Sturgeon Pt MI Including Thunder Bay National Marine Sanctuary; Lake Huron from 5NM east of Mackinac Bridge to Presque Isle Lt to the US/Canadian border beyond 5 NM from shore; Lake Huron from Presque Isle Lt. to Sturgeon Point MI 5NM off shore to US/Canadian border |
| Headline | Special Marine Warning issued May 18 at 3:42PM EDT until May 18 at 5:15PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-05-18T17:15:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.8dc641cc039726fcd16d58f69ff6f1538fda9e70.001.1","noaa_urn:oid:2.49.0.1.840.0.6f2474ed70950cee70985cdf97b330be95862e4b.001.1"] |
| Iem TypeSummary | R |
| Iem Magnitude | 1.02 |
| Iem Unit | Inch |
| Iem City | 6 S Cathro |
| Iem County | Alpena |
| Iem State | MI |
| Iem Wfo | APX |
| Iem Remark | ASOS station KAPN Alpena - Phelps Collins Field. |
| MergedSources | [{"id":"iem_R_45.070_-83.570_1779119640000","source":"iem","severity":"low","severityValue":25,"timestamp":1779119640000,"latitude":45.07,"longitude":-83.57}] |
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.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 22/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.