Live incident briefing · Flood
Flash Flood Warning near Guam, GU
Official warning geography and instructions, rainfall outlook, gauge observations and forecasts, affected places, and source history.
- Official source updated
- 10 hr ago
- Briefing status
- Active
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Official information and local resources
Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles.
NWS Tiyan GU · source Aug 30, 2026, 9:35 AM
State resourceGuam Homeland Security and Office of Civil Defense↗federalOfficial Flash Flood Warning↗
In immediate danger? Call 911. Nature Says When is not an emergency service and does not determine whether an area is safe.
Verified context
What the latest evidence says
Official Flash Flood Warning information identifies Guam, GU as the affected area. The event severity is Severe, with urgency listed as Immediate.
From the primary source
Official incident details
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FFWGUM The National Weather Service in Tiyan has issued a * Flash Flood Warning for... Southwestern coasts of Guam... * Until 1030 PM ChST. * At 735 PM ChST, Doppler radar indicated heavy rain across the warned area. Additional rainfall amounts of 2 to 3 inches are possible in the warned area. Flash flooding is ongoing or expected to begin shortly. HAZARD...Flash flooding caused by heavy rain. SOURCE...Radar indicated. IMPACT...Flash flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other poor drainage and low-lying areas. * Some locations that will experience flash flooding include... Merizo, Piti, Santa Rita and Umatac. Apra Harbor and Naval Base Guam.
NWS Tiyan GU · source Aug 30, 2026, 9:35 AM
Official forecast
NWS weather context
Source-timed facts
Current incident picture
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- Affected areas
- Guam, GU National Weather Service · source Aug 30, 2026, 9:35 AM
- County count
- 1 counties National Weather Service · source Aug 30, 2026, 9:35 AM
- Official alert
- Flash Flood Warning National Weather Service · source Aug 30, 2026, 9:35 AM
- Severity
- Severe National Weather Service · source Aug 30, 2026, 9:35 AM
- Ugc county codes
- GUC010 National Weather Service · source Aug 30, 2026, 9:35 AM
- Urgency
- Immediate National Weather Service · source Aug 30, 2026, 9:35 AM
- Warning count
- 1 warnings National Weather Service · source Aug 30, 2026, 9:35 AM
- Represented population
- 0 people U.S. Census Bureau 2020 Decennial Census · source Apr 1, 2020, 12:00 AM
Geographic context
Incident area and nearby places
Map geometry shows the official source shape when available. It does not predict impact outside or inside the line.
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Map-equivalent affected-area text
Guam, GU
Source center: 13.341, 144.653. A point or perimeter is context, not a safety boundary.
- Guam, GU
Material revisions
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Incident first observed.
Provenance and handoffs
Official sources
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state · emergencyGuam Homeland Security and Office of Civil DefenseVerified Aug 30, 2026, 10:45 AMfederal · weatherOfficial Flash Flood WarningVerified Aug 30, 2026, 10:45 AM
How this briefing is assembled
Source facts are stored with source and retrieval times. The page renders stored records only. Optional generated context is omitted whenever validation fails and never controls emergency instructions, containment, road status, health guidance, or publication.