Tropical Storm Warning Issued for Guam Coastal Waters

Source: NOAA · Guam Coastal Waters

If you are in immediate danger, call emergency services now.

For real-time, official alerts and instructions for your exact location, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia) as applicable. This article is a data summary, not a substitute for the issuing agency's live warning.

Areazine synthesizes this NWS weather alert directly from NOAA's official public data feed. See our methodology for full source attribution and refresh cadence.

A Tropical Storm Warning is in effect for Guam Coastal Waters, with tropical storm force winds of 40 to 60 knots expected as early as late Monday afternoon and possible typhoon conditions within 48 hours.

What this NWS weather alert tells you, and what most readers miss

This notice was issued by NOAA on April 12, 2026 and geographically references Guam Coastal Waters. Its severity classification of "high" signals how the issuing agency weighs the risk of harm if no action is taken - "critical" and "high" tier alerts typically carry direct consumer actions, while "medium" and "low" tend toward informational guidance or monitoring advisories. The category it belongs to - Weather Alerts - determines the warning protocol behind it, which shapes what protective action (seeking shelter, following evacuation orders if issued, monitoring official updates) is recommended and which agency holds authority to issue or cancel it.

Most readers skim a notice like this, check whether they are personally affected, and move on. The more useful lens is to read it as a data point about the issuing system: how quickly NOAA detected the hazard, how precise the geographic or product-identifier scope is, and whether similar notices have clustered in the same category or region in the last 90 days. Cluster patterns frequently precede a broader regulatory action, a single localized NWS weather alert is isolated; three of them within a quarter often indicate a supply-chain, infrastructure, or seasonal driver that will keep producing notices until something structural changes.

For decision-making, Areazine pairs each alert with the original agency URL, the full agency name, and a timestamp so you can verify the notice against the primary source before acting on it. Tags on this item (weather, alert, Tropical Storm Warning, Guam) map to related alerts in the same area of risk - browsing them together gives a clearer picture than any single notice alone, because the shape of an ongoing issue only becomes visible across multiple sequential alerts.

Alert Details

A Tropical Storm Warning has been issued by NWS Tiyan GU. It is effective from April 12, 2026, at 4:14 PM ChST.

Affected Areas

The warning affects Guam Coastal Waters.

What You Should Do

Inexperienced mariners, especially those operating smaller vessels, should avoid boating in hazardous conditions. Seek safe harbor as soon as possible, as venturing out can result in significant threat to life and/or property.

Expected Conditions

Tropical storm force winds of 40 to 60 knots are expected. Typhoon conditions, including winds of 64 knots or more, are possible within the next 48 hours. Conditions are expected to be incredibly dangerous for small craft and also pose a threat to large vessels.

Timeline

The alert is effective from April 12, 2026, at 4:14 PM ChST and expires on April 13, 2026, at 6:00 AM ChST. It is in effect through at least Wednesday morning.

Original source: NOAA Official Notice ↗

All Weather Alerts →

Frequently Asked Questions

Common questions about this NWS weather alert.

What is this NWS weather alert about?
A Tropical Storm Warning is in effect for Guam Coastal Waters, with tropical storm force winds of 40 to 60 knots expected as early as late Monday afternoon and possible typhoon conditions within 48 hours.
Which agency issued this alert?
This alert was issued by NOAA. The original notice is available at the source link at the bottom of this article.
How severe is this alert?
This alert is classified as "high" severity. Take precautions and monitor for updates.
What area is affected?
This alert affects Guam Coastal Waters. Check with NOAA for the most current geographic scope.
Where can I find more Weather Alerts updates?
Browse the full Weather Alerts feed on Areazine at areazine.com/weather/ for the latest updates from NOAA and other agencies.