NASA Finds Heaviest Rainfall in Tropical Cyclone Gita’s Northern Quadrant

NASA’s GPM core satellite examined rainfall in Tropical Cyclone Gita soon after the storm came together. Tropical Cyclone Gita formed near American Samoa in the Southwestern Pacific Ocean and triggered warnings and watches on Feb. 9. A Tropical Cyclone Warning is in force for Niue.

On Feb. 9 at 9:26 a.m. EST (1426 UTC) GPM found heaviest rainfall from storms northwest of the Gita’s center dropping rain at a rate of greater than 1 to 1.6 inches per hour. Rainfall in fragmented bands of thunderstorms east of the center were dropping rainfall up to 1 inch per hour. GPM data was overlaid on infrared data from Japan’s Himawari-8 satellite in this image.
Credit: NASA/JAXA/NRL

The GPM or Global Precipitation Measurement mission core observatory satellite passed above Gita on February 9, 2018 at 9:26 a.m. EST (1426 UTC). GPM found heaviest rainfall from storms northwest of the center. In the northwestern quadrant, rain was falling at a rate of greater than 1 to 1.6 inches per hour (25 to 40 millimeters per hour). Rainfall in fragmented bands of thunderstorms east of the center were dropping rainfall up to 1 inch per hour (25 millimeters per hour).

GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

On Feb. 9 at 9 a.m. EST (1500 UTC) Tropical Cyclone Gita was located near 14.8 south latitude and 172.3 west longitude. That’s about 134 nautical miles west-southwest of Pago Pago. Gita was moving to the east at 17.2 mph (15 knots/27.7 kph) and had maximum sustained winds near 51.7 mph (45 knots/83.3 kph).

The Joint Typhoon Warning Center (JTWC) predicts Gita will rapidly intensify to hurricane-strength over the next day and turn southwest then west toward Tonga. The JWTC forecast takes Gita’s center close to the island of Tonga on Feb. 12 and the storm is expected to track south of Fiji.

Source: NASA

Flood Summary

Last updated: February 21, 2018
Event
Tropical Cyclone Gita, Samoa, American Samoa, Tonga, Fiji and New Zealand
Date
February 7, 2018
Type
Flash flood, Landslide
Cause
Extreme rainfall

Locations

A - Matautu, Faatoia, Savaii, Afega and Malie (Samoa)
B - Faatoia (Samoa)
C - Savaii (Samoa)
D - Afega (Samoa)
E - Saleapaga (Samoa)
F - Solosolo (Samoa)
G - Pago Pago (American Samoa)
H - Tongatapu (Tonga)
I - ‘Eua (Tonga)
J - Ha’apai (Tonga)
K - Riwaka (New Zealand)
L - Tasman (New Zealand)
M - New Plymouth (New Zealand)
N - Takaka (New Zealand)

Magnitude

River level
Overflowing
Vaisigano River, Apia, Samoa - February 9 to February 11, 2018
Rainfall level
105 mm in 24 hours
Apia / Upolu Island, Samoa - February 10 to February 11, 2018
Ogimet figures
Rainfall level
204 mm in 24 hours
Le Piu Tai, Samoa - February 9 to February 10, 2018
Rainfall level
200.5 mm in 24 hours
Maota Int Airport, Samoa - February 9 to February 10, 2018
Rainfall level
402 mm in 24 hours
Mt Talu, Samoa - February 9 to February 10, 2018
Rainfall level
264 mm in 24 hours
Apia / Upolu Island, Samoa - February 9 to February 10, 2018
Rainfall level
212.5 mm in 24 hours
Le Piu Tai, Samoa - February 8 to February 9, 2018
Rainfall level
314 mm in 24 hours
Mt Talu, Samoa - February 8 to February 9, 2018
Rainfall level
647.5 mm in 24 hours
Le Piu Tai, Samoa - February 7 to February 8, 2018
Rainfall level
262.5 mm in 24 hours
Maota Int Airport, Samoa - February 7 to February 8, 2018
Rainfall level
627.5 mm in 24 hours
Maota Int Airport, Samoa - February 7 to February 8, 2018
Rainfall level
109 mm in 24 hours
Pago Pago, American Samoa - February 8 to February 9, 2018
Rainfall level
68.6 mm in 24 hours
Niuafoʻou, Tonga - February 10 to February 11, 2018
Rainfall level
80.6 mm in 24 hours
Wellington, New Zealand - February 20 to February 21, 2018
Note; Figure for New Zealand from MetService NZ for the duration of the storm, therefore possibly longer period than 24 hours.
Rainfall level
80.6 mm in 24 hours
Kelburn, New Zealand - February 20 to February 21, 2018
Rainfall level
69.2 mm in 24 hours
Christchurch Airport, New Zealand - February 20 to February 21, 2018
Rainfall level
96.6 mm in 24 hours
Le Bons Bay, New Zealand - February 20 to February 21, 2018
Rainfall level
60.2 mm in 24 hours
Dunedin Airport, New Zealand - February 20 to February 21, 2018
Rainfall level
296.5 mm in 24 hours
Hundalee Ranges south of Kaikoura, New Zealand - February 20 to February 21, 2018

Damages

Evacuated
244 people
Samoa - February 9 to February 12, 2018
Roads damaged
30 roads
Samoa - February 9 to February 12, 2018
Estimated figure. Numerous roads suffered flood and landslide damage, according to Samoa Land Transport Authority
Fatalities
1 person
Tonga - February 11 to February 13, 2018
Evacuated
3,900
Tonga - February 11 to February 13, 2018
Buildings destroyed
95 buildings
Tonga - February 11 to February 13, 2018
Much of the damage was a result of strong winds
Evacuated
200 people
Nelson-Tasman Region, New Zealand - February 20 to February 21, 2018