First published Oct 18, 2026, 9:17:16 AM UTC · Last updated Oct 18, 2026, 9:17:16 AM UTC

NWS Tiyan issues Special Marine Warning for Guam coastal waters amid waterspout threat

NWS Tiyan issued a warning for Guam coastal waters until 7:30 p.m. ChST after a shower capable of producing waterspouts was located over eastern Guam waters. The warning instructed boaters to seek safe harbor immediately.

Why it matters

The warning states that waterspouts can overturn boats and create locally hazardous seas.

Location

Categories: severe-weather-and-natural-disasters

Generated scores

Scores are based on the cited reporting and use a 1–10 scale. Read the methodology.

Confidence: 8/10How certain the assessment is based on the clarity and evidence in the cited reporting.
Geographic reach: 1/10How widely the event reaches, from a local area (1) to worldwide impact (10).
Global importance: 2/10The event's broader significance, from limited importance (1) to major global importance (10).
Impact magnitude: 3/10The scale or severity of the real-world impact, from minor (1) to extreme (10).
Positivity: 3/10How harmful or beneficial the event is, from strongly harmful (1) to strongly positive (10).
Urgency: 9/10How time-sensitive the event is, from low urgency (1) to immediate attention needed (10).

Primary official sources

U.S. National Weather Service Alerts NWS Special Marine Warning issued October 18 at 7:03PM ChST until October 18 at 7:30PM ChST by NWS Tiyan GU

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