NOAA NWS / Event history
Special Marine Warning issued October 17 at 11:21AM ChST until October 17 at 11:45AM ChST by NWS Tiyan GU
Special Marine Warning · Guam Coastal Waters. Severe; likely; urgency: immediate.
- Bulletin issued
- 17 October 2026 at 01:21 UTC
- First saved by us
- 17 October 2026 at 01:32 UTC
- Last included in a daily record
- 17 October 2026
The linked daily edition preserves what we captured that UTC day; this event page is not a live warning.
- Source classification
- Severe · Source alert
A recent feed check does not mean a new observation. This page preserves source records; it does not establish current safety or warning status.
- Issuer / area
- NWS Tiyan GU · Guam Coastal Waters
- Certainty / urgency
- Likely / Immediate
- Message expiry (not hazard end)
- 17 October 2026 at 01:45 UTC
- Forecast onset / end
- 17 October 2026 at 01:21 UTC / 17 October 2026 at 01:45 UTC
Archived official description
SMWGUM THE NATIONAL WEATHER SERVICE IN TIYAN HAS ISSUED A * SPECIAL MARINE WARNING FOR... SOUTHEASTERN GUAM COASTAL WATERS... * UNTIL 1145 AM CHST. * AT 1121 AM CHST, A SEVERE THUNDERSTORM PRODUCING WATERSPOUTS WAS LOCATED 33 NM SOUTHEAST OF IPAN BUOY, MOVING SOUTH AT 30 KNOTS. HAZARD...WATERSPOUTS. SOURCE...RADAR INDICATED. IMPACT...WATERSPOUTS CAN EASILY OVERTURN BOATS AND CREATE LOCALLY HAZARDOUS SEAS. * LOCATIONS IMPACTED INCLUDE... MAINLY OPEN WATERS OF SOUTHEASTERN GUAM COASTAL WATERS.
Instructions in this archived message
MOVE TO SAFE HARBOR UNTIL HAZARDOUS WEATHER PASSES.
The saved record
What changed
0 updates · 1 first record
Each update compares two versions we saved. This may not include every update from the source. A missing report does not mean an event has ended.
First saved record · 17 October 2026 at 01:32 UTC
Saved by us
Starting point
First saved record
Our first saved version of Special Marine Warning issued October 17 at 11:21AM ChST until October 17 at 11:45AM ChST by NWS Tiyan GU. We have no earlier saved version to compare.
Bulletin issued: 17 October 2026 at 01:21 UTC
View saved version 1
Original saved fields, unchanged. This is our record, not an archived copy of the external webpage.
{ "id": "nws:15ad588a3292ac8b78316fc2", "authorityId": "urn:oid:2.49.0.1.840.0.6ffca5e345070f4c69a4f4b1396149543ae37fa2.001.1", "sender": "w-nws.webmaster@noaa.gov", "references": [], "category": "weather", "title": "Special Marine Warning issued October 17 at 11:21AM ChST until October 17 at 11:45AM ChST by NWS Tiyan GU", "eventType": "Special Marine Warning", "occurredAt": "2026-10-17T01:21:00.000Z", "issuedAt": "2026-10-17T01:21:00.000Z", "timeBasis": "Bulletin issued", "effectiveAt": "2026-10-17T01:21:00.000Z", "onsetAt": "2026-10-17T01:21:00.000Z", "expiresAt": "2026-10-17T01:45:00.000Z", "forecastEndAt": "2026-10-17T01:45:00.000Z", "severity": "Severe", "urgency": "Immediate", "certainty": "Likely", "messageType": "Alert", "status": "Source alert", "place": "Guam Coastal Waters", "coordinates": null, "issuer": "NWS Tiyan GU", "summary": "Special Marine Warning · Guam Coastal Waters. Severe; likely; urgency: immediate.", "description": "SMWGUM\n\nTHE NATIONAL WEATHER SERVICE IN TIYAN HAS ISSUED A\n\n* SPECIAL MARINE WARNING FOR...\nSOUTHEASTERN GUAM COASTAL WATERS...\n\n* UNTIL 1145 AM CHST.\n\n* AT 1121 AM CHST, A SEVERE THUNDERSTORM PRODUCING WATERSPOUTS WAS\nLOCATED 33 NM SOUTHEAST OF IPAN BUOY, MOVING SOUTH AT 30 KNOTS.\n\nHAZARD...WATERSPOUTS.\n\nSOURCE...RADAR INDICATED.\n\nIMPACT...WATERSPOUTS CAN EASILY OVERTURN BOATS AND CREATE LOCALLY\nHAZARDOUS SEAS.\n\n* LOCATIONS IMPACTED INCLUDE...\nMAINLY OPEN WATERS OF SOUTHEASTERN GUAM COASTAL WATERS.", "instruction": "MOVE TO SAFE HARBOR UNTIL HAZARDOUS WEATHER PASSES.", "url": "https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.6ffca5e345070f4c69a4f4b1396149543ae37fa2.001.1", "source": "nws", "sourceName": "NOAA NWS" }Visit the external source ↗The external page may have changed since this version was saved.