Flash Flood and High Wind in American Samoa, February 16 to 17, 2020

Name: Flash Flood and High Wind in American Samoa, February 16 to 17, 2020
Start: 2020-02-16T01:48
End: 2020-02-17T23:00
Location: American Samoa

February 16 to 17, 2020 · NWS ASO · 8 events in 1 county or zone

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $66,000
Crop damage: $27,000
Events: 8

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS ASO wrote it up.

An extremely active monsoonal trough in the region of American Samoa, generated an extended period of damaging winds, high surf and flooding rains. Moderate values of mid level shear and stable flow into the eastern portions of the area of responsibility hindered any one tropical circulation from developing within the trough. Therefore, there was no named tropical feature with this event. The extensive amounts of damage noted during this period, is what likely lessened storm damage experienced as Tropical Storm Vicky and Tropical Storm Wasi developed later in the week.

An extended period of sustained winds 35 to 45 mph with frequent gusts 65 to 70 mph, generated widespread damage across the American Samoan Island chain. Strong winds began over Manua Saturday Feb 15th with all of American Samoa experiencing damage Sunday Feb 16th, through early Monday Feb 17th. During this time several reports of roof damage, downed trees, downed power lines and power outages, and rock slides.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

3 high wind, 2 high surf, 1 strong wind, 1 flash flood, 1 heavy rain. Local standard time, as filed.

Strong Wind, Tutuila

When: February 16, 1:48 AM SST
Where: Tutuila forecast zone
Measured: 37 kt (43 mph) measured gust
Property damage: $5,000
Crop damage: $5,000
Reported by: Official NWS Observations

NWS 01:48am non-tstm wind gust.

Flash Flood, Tutuila

When: February 16, 3:00 AM SST
Where: Tutuila County, 5.57 mi NW of Vaitogi to 5.09 mi NW of Vaitogi
Cause: Heavy Rain
Property damage: $1,000
Crop damage: $1,000
Reported by: Official NWS Observations
Coordinates: -14.348, -170.763

Total rainfall recorded over a 24 hour period 3.43 inches. Flooding on roads reported in several villages.

High Surf, Tutuila

When: February 16, 2:00 PM SST to February 17, 2:00 PM SST
Where: Tutuila forecast zone
Property damage: $5,000
Reported by: County Official

High Wind, Tutuila

When: February 16, 2:01 PM SST
Where: Tutuila forecast zone
Measured: 51 kt (59 mph) measured gust
Property damage: $5,000
Crop damage: $5,000
Reported by: Official NWS Observations

NWS Pago Pago official observation.

High Surf, Tutuila

When: February 16, 6:00 PM SST to February 17, 5:00 AM SST
Where: Tutuila forecast zone
Property damage: $10,000
Crop damage: $5,000
Reported by: Buoy

High surf from an extended period of tropical convection 200 to 300 miles northwest of American Samoa and persistent strong northwest flow, generated an extended period of high surf and water piling onshore along American Samoan's north shoreline. Villages along north shores were battered by strong winds and high surf of 20 to 26 feet generating beach erosion, and coastal flooding. Many areas reported debris on roads. Vessels ordered by port admin to anchor outside of harbor due to winds and large surfs.

High Wind, Tutuila

When: February 16, 11:34 PM SST
Where: Tutuila forecast zone
Measured: 59 kt (68 mph) measured gust
Property damage: $5,000
Crop damage: $5,000
Reported by: Official NWS Observations

An official NWS observation. Highest winds recorded was 43G68 mph. Family in Fagatogo Village lost entire roof to their home. Family in Aunu'u lost the roof to their home. Roof blown off museum in Fagatogo. Krispy Crunchy Chicken Restaurant lost the back patio. Radio station KHJ had damage to its communication tower due to strong winds. Power outages in Afono and Vatia. Samoa Airways and Talofa Airways cancelled their afternoon flights due to winds. Crops uprooted in Manu'a.

Heavy Rain, Tutuila

When: February 17, 12:00 AM SST to 11:00 PM SST
Where: Tutuila County, 78.65 mi E of Pago Pago to 78.71 mi E of Pago Pago
Property damage: $30,000
Crop damage: $1,000
Reported by: Emergency Manager
Coordinates: -14.216, -169.429

Road between Ta'u and Fitiuta cut off by a landslide in Manu'a due to 3.8 inches of rain recorded over a 24 hour period.

High Wind, Tutuila

When: February 17, 12:38 PM SST
Where: Tutuila forecast zone
Measured: 50 kt (58 mph) measured gust
Property damage: $5,000
Crop damage: $5,000
Reported by: Other Federal Agency

Impacts from the 16th is combined with the 17th as this weather event was from one day to the next. Heavy crop damage. Several homes lost their roofs.

What these are

Strong Wind: Non-thunderstorm winds below high wind criteria that nonetheless caused damage or casualties.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
High Surf: Large waves breaking on the shore that caused damage, erosion or casualties.
High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.
Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in American Samoa in 2020 Every state in 2020 This day in weather history Warnings in American Samoa, February 2020

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 870874, 897841, 870888, 870875, 897840, 870881, 897842, 870880.