Special Marine Warning for Guam Coastal Waters: Waterspouts and High Winds Possible
This alert is no longer in effect.
NOAA issued it on April 6, 2026, 4 months ago. Warnings of this kind stay in effect for hours to a few days, so this page is a historical record of what was issued, not a current warning. For conditions where you are right now, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia).
Areazine synthesizes this NWS weather alert directly from NOAA's official public data feed. See our methodology for full source attribution and refresh cadence.
The National Weather Service has issued a Special Marine Warning for Guam Coastal Waters until 8:30 AM ChST due to a severe thunderstorm capable of producing waterspouts and high wind gusts.
Read this weather record in 30 seconds
- Record type
- Special Marine Warning
- Affected area
- Guam Coastal Waters
- Issued
- April 6, 2026
- Issuing authority
- NWS Tiyan GU
Marine notices apply to named waters or shoreline zones. They may not describe conditions on land, even when the nearest place name is the same.
Record status: historical. It was issued 4 months ago; use the issuing agency's live warning service for current conditions in Guam Coastal Waters.
Alert Details
The National Weather Service in Tiyan, Guam, has issued a Special Marine Warning (SMWGUM) for the region. The alert was issued at 7:54 AM ChST on March 2, 2026, following radar detection of hazardous weather conditions.
Affected Areas
The warning specifically covers the Guam Coastal Waters. At the time of the alert, a severe thunderstorm was located over Apra Harbor, moving southwest at approximately 20 knots. The storm is expected to remain primarily over open waters.
What You Should Do
Mariners and residents in the affected area are advised to move to safe harbor immediately. You should remain in a secure location until the hazardous weather passes. Thunderstorms can produce sudden waterspouts that can easily overturn boats and create locally hazardous seas. Small craft are particularly vulnerable and could be damaged by briefly higher winds and suddenly higher waves.
Expected Conditions
- Hazards: Potential waterspouts and wind gusts of 34 knots or greater.
- Seas: Suddenly higher waves and locally hazardous sea conditions are expected near the thunderstorm.
- Movement: The storm system is moving southwest at 20 knots.
Timeline
The Special Marine Warning is effective immediately as of 7:54 AM ChST and is currently scheduled to expire at 8:30 AM ChST on March 2, 2026.
Original source: NOAA Official Notice ↗
Related Weather Alerts
All Weather Alerts →Frequently Asked Questions
Common questions about this NWS weather alert.