Severe Flood ● Closed
Flood Watch issued September 21 at 3:35PM ChST until September 23 at 10:00PM ChST by NWS Tiyan GU, United States of America
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* WHAT...Flash flooding caused by excessive rainfall is possible.
* WHERE...Guam.
* WHEN...From Tuesday morning through Wednesday evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Flooding may occur in poor drainage and urban areas. Low-water
crossings may be flooded.
* ADDITIONAL DETAILS...
- Heavy rainfall from Invest 91W located south of Guam may lead to
flash flooding Tuesday through Wednesday evening. Guidance shows
2 to 5 inches of rain falling during the watch period as Invest
91W moves just west of Guam. Many locations across Guam have
already seen 2 to 4 inches of rain since Saturday and soils
remain wet from heavy rainfall the last couple of weeks. This
will allow for a lower threshold for flash flooding over the next
couple of days.
- http://www.weather.gov/safety/flood
Measurements
| Coordinates | 39.9645, -100.8105 |
|---|---|
| Region | Guam |
| Location Precision | country |
| Issuing Authority | United States of America — us-noaa-nws-en |
| Cap Urgency | Future |
| Cap Certainty | Possible |
| Cap Expires | 2026-09-22T06:15:00+10:00 |
Official source
Warnings courtesy of the issuing national meteorological service, via the WMO Alert Hub.
This is an official warning issued by the authority named above. Follow its instructions and those of your local emergency services.
Severity as published by WMO Alert Hub (national weather services).
View original reportThis event as JSON · API and licence
Source updated 28 days ago (Sep 21, 2026 05:37 UTC) · we last heard from WMO Alert Hub (national weather services) 1 minute ago
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About this location
The agency did not publish coordinates for this warning. The pin is the centre of the country, not the location of the event — read the area name, not the map, for where it applies.
Area as the agency stated it: Guam
Official authorities in United States
If you are there, these are the bodies whose instructions apply. This site is not an emergency service and does not issue warnings.
More for United States →What to do
Follow the instructions issued by WMO Alert Hub (national weather services) and your local emergency services. The guidance below is background.
Flood preparation, evacuation decisions, and the dangers of driving or walking through floodwater.
Open Flood Safety Guide →Earlier flood events in United States
Severe and extreme events of the same kind, before this one. Listed for scale, not because they are connected to it.
Nearby & related events
Disclaimer: figures are automatic feeds from the named agencies and may be revised. Do not use this page for life-safety decisions — follow official local emergency services.