Guam Flash Flood Warning | Effective 04/12/2026 09:49

Headline: 
Flash Flood Warning issued April 13 at 2:49AM ChST until April 13 at 3:30AM ChST by NWS Tiyan GU
Event: 
Flash Flood Warning
Urgency: 
Immediate
Effective: 
April 12, 2026 - 9:49am
Expires: 
April 12, 2026 - 10:30am
Description: 
FFWGUM The National Weather Service in Tiyan has issued a * Flash Flood Warning for... Southwestern Guam... * Until 330 AM ChST. * At 249 AM ChST, Doppler radar and automated rain gauges indicated heavy rain falling across the warned area. Between 0.6 and 1.4 inches of rain have fallen. The expected rainfall rate is 1 to 2.5 inches in 1 hour. Additional rainfall amounts of 1 to 2.4 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 and automated gauges. IMPACT...Flash flooding of small creeks and streams, urban areas, and streets as well as other poor drainage and low-lying areas. * Some locations that will experience flash flooding include... Chalan Pago-Ordot, Yona, Hagatna Heights, Talofofo, Mongmong-Toto-Maite, Sinajana, Inarajan, Asan, Merizo, Piti, Santa Rita and Umatac.
Instruction: 
Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. Be especially cautious at night when it is harder to recognize the dangers of flooding. Be aware of your surroundings and do not drive on flooded roads. In hilly terrain there are hundreds of low water crossings which are potentially dangerous in heavy rain. Do not attempt to cross flooded roads. Find an alternate route. Please report observed flooding to local emergency services or law enforcement and request they pass this information to the National Weather Service when you can do so safely.
Area Description: 
Guam, GU
Forcast Office: 
NWS Tiyan GU
Sender: 
w-nws.webmaster@noaa.gov