Coastal Flood Watch issued October 16 at 10:48PM ChST until October 19 at 4:00AM ChST by NWS Tiyan GU
Official severe-weather alerts, warning areas, and disaster updates.
expired · active · official-source
* WHAT...For the High Surf Warning, large, hazardous breaking waves of 7 to 9 feet Saturday afternoon will become dangerous, building to as high as 35 feet for Guam, 25 feet for Rota and 20 feet for Tinian and Saipan. For the Coastal Flood Watch, significant coastal flooding possible. * WHERE...For the High Surf Warning, initially east facing reefs of Guam, Rota, Tinian, and Saipan; spreading to all reefs through Sunday afternoon. The Coastal Flood Watch is also for all reefs of the Marianas. * WHEN...For the High Surf Warning, from 5 PM Saturday to 4 AM ChST Monday. For the Coastal Flood Watch, from Saturday afternoon through late Sunday night. * IMPACTS...Numerous roads may be closed. Low lying property including homes, businesses, and some critical infrastructure may be inundated. Some shoreline erosion may occur. Breaking waves can sweep people off jetties and docks, and into dangerous seas. Life-threatening swimming conditions and significant beach erosion can be expected. Coastal inundation of 5 to 7 feet for Guam, 2 to 4 feet for Rota and 1 to 3 feet for Tinian and Saipan is possible along with coastal flooding and beach erosion. * ADDITIONAL DETAILS...As TS Champi approaches the Marianas, surf conditions are expected to deteriorate rapidly, with surf reaching 9 feet Saturday afternoon, building to dangerous/deadly levels through Saturday night. Everyone should remain out of the water due to life-threatening surf conditions. Stay off of jetties, piers, and other waterside infrastructure.
- Event time
- Source last updated
- Current version retrieved
- Provider
- NWS — active weather alerts (Storm)
- Location
- US
- Severity
- Moderate
- area
- Guam; Rota; Tinian; Saipan
- event
- Coastal Flood Watch
- onset
- 2026-10-17T17:00:00+10:00
- states
- ["GU","MP"]
- urgency
- Future
- certainty
- Possible
- effective
- 2026-10-16T22:48:00+10:00
- message id
- urn:oid:2.49.0.1.840.0.c8524ef2c627a2fa5742d2e69771101f184f796f.001.2
- references
- ["urn:oid:2.49.0.1.840.0.91151f8264ddf087c81419691c5146508936ca1d.001.2"]
- instruction
- Everyone should remain out of the water due to life-threatening surf conditions. Stay off of jetties, piers, and other waterside infrastructure.
- message type
- Update
- location basis
- Approximate: centers of the NWS zones listed in the alert
- freshness minutes
- 60
Source use policy · US government work (17 U.S.C. 105)
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Locations and boundaries are as supplied by each source. Area statistics without an exact location are placed at the Census center of their city, county or ZIP code and labeled approximate. Refer to official instructions for current conditions.
Update history (2 recent revisions)
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