Flash Flood Warning issued for Southwestern Guam
This alert is no longer in effect.
NOAA issued it on August 30, 2026, 3 weeks 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.
NWS Tiyan GU has issued a Flash Flood Warning for southwestern coasts of Guam until 10:30 PM ChST due to heavy rain and ongoing flash flooding.
The weather record, at a glance
- Record type
- Flash Flood Warning
- Affected area
- Guam
- Issued
- August 30, 2026
- Issuing authority
- NWS Tiyan GU
Flood notices turn on location and timing. Treat the named area as this record's scope; do not assume nearby counties, parishes, or waterways were included.
Record status: historical. It was issued 3 weeks ago; use the issuing agency's live warning service for current conditions in Guam.
Alert Details
Flash Flood Warning issued by NWS Tiyan GU. Effective from August 30, 2026 at 7:35 PM ChST until August 30, 2026 at 10:30 PM ChST. Severity: Severe. Urgency: Immediate. Certainty: Likely.
Affected Areas
Southwestern coasts of Guam, including Merizo, Piti, Santa Rita, Umatac, Apra Harbor, and Naval Base Guam.
What You Should Do
Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles.
Expected Conditions
Doppler radar indicated heavy rain across the warned area. Additional rainfall amounts of 2 to 3 inches are possible. Flash flooding caused by heavy rain is ongoing or expected to begin shortly. Impacts include flash flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other poor drainage and low-lying areas.
Timeline
Alert effective August 30, 2026 at 7:35 PM ChST. Expires and ends August 30, 2026 at 10:30 PM ChST.
Original source: NOAA Official Notice ↗
Related Weather Alerts
All Weather Alerts →Elsewhere in the country: similar length or severity timing 8
Two cross-category peer sets, both computed from Areazine's own archive: notices with a similar body length, and notices near the same severity and agency date. These are drawn from other categories, not the same-feed Related list above.
Similar body length
Nearest notices by article body length (939 characters here).
Similar severity timing
Same severity (high) notices issued closest in time to August 30, 2026.
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