Storm Reports

Typhoon Sinlaku to Impact the Marianas and Guam; Severe Weather from the Southern Plains to the Great Lakes

Typhoon Sinlaku will bring destructive winds, widespread heavy rain/flooding, thunderstorms, and coastal impacts to the Marianas Islands into Wednesday. Typhoon conditions are likely over CNMI and tropical storm conditions over Guam. Severe thunderstorms and heavy rain are expected from the Southern Plains to the Great Lakes today. Read More >

How to Report Significant Weather
Use this national web based/mobile form: Submit Report Report using the mPING app. For more info: mPING Info Facbook NWSGuam Twitter @NWSGuam Call our office at 671-472-0900 Please include in your report, the location and time/date that the severe/notable weather occurred. If you can supply a picture of the significant weather, please do by sending them to our social media accounts.

How to Report Significant Weather

Use this national web based/mobile form: Submit Report
Report using the mPING app. For more info: mPING Info
Facbook NWSGuam
Twitter @NWSGuam
Call our office at 671-472-0900

Please include in your report, the location and time/date that the severe/notable weather occurred.

If you can supply a picture of the significant weather, please do by sending them to our social media accounts.

When to Send a Storm Report
When you can do so safely, please send us a report when you observe one or more of the following: Coastal Flooding High Surf (9 feet or greater) Heavy Rainfall/Flash Flooding Wind damage Tornado/Waterspout Hail (Any size) 0.25" or less - Pea 0.50" - Mothball 0.75" - Dime/Penny 0.88" - Nickel 1.00" - Quarter 1.25" - Half Dollar 1.50" - Walnut/Ping Pong 1.75" - Golf Ball 2.00" - Hen Egg 2.50" - Tennis Ball 2.75" - Baseball 3.00" - Tea Cup 4.00" - Softball 4.50" - Grapefruit Please note that 1.00 inch or greater hail is considered severe. Definitions: Flash Flood: A life-threatening rapid rise of water which is caused by heavy or excessive rainfall in a short period of time, generally less than 6 hours. Also, at times a dam failure can cause a flash flood, depending on the type of dam and time period during which the break occurs. Coastal Flood: Flooding of coastal area due to the vertical rise above normal water level caused by strong, persistent onshore wind, high astronomical tide, and/or low atmospheric pressure, resulting in damage, erosion, flooding, fatalities, or injuries. Tornado: A violently rotating column of air, usually pendant to a cumulonimbus, with circulation reaching the ground. It nearly always starts as a funnel cloud and may be accompanied by a loud roaring noise. On a local scale, it is the most destructive of all atmospheric phenomena. Waterspout: A tornadic type of vortex that forms over water and are typically brief and weak. Can still cause damage and are hazardous to boats. Severe Thunderstorm: A thunderstorm that produces a tornado, winds of at least 58 mph (50 knots), and/or hail at least 1" in diameter. Structural wind damage may imply the occurrence of a severe thunderstorm. A thunderstorm with winds equal to or greater than 40 mph (35 knots) and/or hail of at least ½" is defined as *approaching severe*.

When to Send a Storm Report

When you can do so safely, please send us a report when you observe one or more of the following:

Coastal Flooding
High Surf (9 feet or greater)
Heavy Rainfall/Flash Flooding
Wind damage
Tornado/Waterspout
Hail (Any size)
- 0.25" or less - Pea
- 0.50" - Mothball
- 0.75" - Dime/Penny
- 0.88" - Nickel
- 1.00" - Quarter
- 1.25" - Half Dollar
- 1.50" - Walnut/Ping Pong
- 1.75" - Golf Ball
- 2.00" - Hen Egg
- 2.50" - Tennis Ball
- 2.75" - Baseball
- 3.00" - Tea Cup
- 4.00" - Softball
- 4.50" - Grapefruit
- Please note that 1.00 inch or greater hail is considered severe.

Definitions:

Flash Flood: A life-threatening rapid rise of water which is caused by heavy or excessive rainfall in a short period of time, generally less than 6 hours. Also, at times a dam failure can cause a flash flood, depending on the type of dam and time period during which the break occurs.
Coastal Flood: Flooding of coastal area due to the vertical rise above normal water level caused by strong, persistent onshore wind, high astronomical tide, and/or low atmospheric pressure, resulting in damage, erosion, flooding, fatalities, or injuries.
Tornado: A violently rotating column of air, usually pendant to a cumulonimbus, with circulation reaching the ground. It nearly always starts as a funnel cloud and may be accompanied by a loud roaring noise. On a local scale, it is the most destructive of all atmospheric phenomena.
Waterspout: A tornadic type of vortex that forms over water and are typically brief and weak. Can still cause damage and are hazardous to boats.
Severe Thunderstorm: A thunderstorm that produces a tornado, winds of at least 58 mph (50 knots), and/or hail at least 1" in diameter. Structural wind damage may imply the occurrence of a severe thunderstorm. A thunderstorm with winds equal to or greater than 40 mph (35 knots) and/or hail of at least ½" is defined as approaching severe.

View Storm Reports
Graphical Storm Reports - during the past 24 hours. Storm Events Database

View Storm Reports

Graphical Storm Reports - during the past 24 hours.
Storm Events Database