Overall Red alert Tropical Cyclone for GITA-18
in Tonga

Impact

Tropical Cyclone GITA-18 can have a high humanitarian impact based on the maximum sustained wind speed,exposed population and vulnerability.

Meteorological source GDACS (JTWC)
Exposed countries Tonga
Exposed population 80 thousand in Category 1 or higher
Maximum wind speed 231 km/h
Maximum storm surge 0.4 m (12 Feb 15:00 UTC)
Vulnerability Medium (Tonga)

GDACS Score

GDACS alert score for Tropical Cyclones is 0.5 (GREEN Alert), 1.5 (ORANGE Alert), 2.5 (RED Alert)
For more info on GDACS alert score click here.
  Wind Storm surge Rainfall GDACS score
GDACS Current 148 km/h 0.4 m n.a. 1.5
GDACS Overall 231 km/h 0.4 m n.a. 1.5

Maximum winds, storm surge, rainfall (Current: over the next 72 h, Overall: entire TC track)

Wind

148 km/h Current

Up to 82000 people in Category 1 strength or higher (see SSHS)

Impact Timeline

Alert Date (UTC) Max Winds (km/h) Population in
Tropical Storm
Population in
Cat. 1 or higher
Countries
Orange 1 09 Feb 2018 00:00 120 390 thousand 80 thousand Tonga
Orange 2 09 Feb 2018 06:00 148 400 thousand 80 thousand Tonga

Bulletin Timeline

Alert Date (UTC) Category Max winds
(km/h)
Population in
Tropical Storm
Population in
Cat.1 or higher
Location (lat, lon) Countries
GREEN
1 09 Feb 2018 00:00 Tropical storm 74 260000 people no people -13.8, -175.5 American Samoa
GREEN
2 09 Feb 2018 06:00 Tropical storm 74 260000 people no people -14.3, -174.5 Niue
GREEN
2 09 Feb 2018 18:00 Tropical storm 102 250000 people no people -15.2, -171.3 Niue
GREEN
2 10 Feb 2018 06:00 Category 1 130 200000 people no people -17.3, -169.1 Niue
GREEN
2 10 Feb 2018 18:00 Category 1 139 1100 people no people -19.5, -168.5 Niue
GREEN
2 11 Feb 2018 06:00 Category 1 139 100000 people no people -21, -169.5 Niue
ORANGE
2 12 Feb 2018 06:00 Category 1 148 110000 people 82000 people -21.8, -173.3 Tonga
GREEN
2 13 Feb 2018 06:00 Category 1 139 100000 people no people -21.5, -178.5 Fiji
GREEN
2 14 Feb 2018 06:00 Category 1 139 no people no people -22, 177.3
Actual track of the current bulletin
The alert for forecast greater than 3 days is limited to Orange level.



Exposed population

Countries

Country
Tonga

Provinces

Region Province Country Population
Tonga Tonga 98000 people

Populated places

Name Region Province Country City class Population Distance
Nuku'alofa Tonga Capital 24000 people 760 km

Critical infrastructure

Airports, ports, nuclear plants and hydrodams at risk, if affected, are listed below.

Airports

Name IATA Code Elevation (m) Usage Runway type IFR Runway Length (ft) Distance
Fua'amotu International TBU 38 Civ. Paved Yes 8700 771 km
Eua Kaufana EUA unknown 0 785 km

Ports

Name LOCODE Country Distance
Nuku'alofa TOTBU Tonga 760 km
Eua Island Tonga 783 km

Rainfall

Rainfall accumulation of the past 24h, as detected by the Global Precipitation Measurement mission of NASA. For more information, see https://www.nasa.gov/mission_pages/GPM/main/index.html.

...

StormSurge

0.4 m

The maximum Storm surge height is  0.4m in Ohonua, Tonga. This height is estimated for 12 Feb 2018 15:00 UTC .

The JRC has developed an experimental global storm surge model, which is run after each advisory issued by the regional tropical cyclone centres. The calculations are published about 20 minutes after a new advisory is detected by GDACS. The calculations identify the populated places affected by storm surge up to three days in advance, using the forecasted track. When forecasts change, the associated storm surge changes too and alert levels may go up or down. All links, data, statistics and maps refer to the latest available calculation. If the calculation for the last advisory is not completed, the latest available calculation is shown.

Locations affected by Storm surge (53 locations). Calculation based on advisory number 2 of 09 Feb 2018 06:00:00 UTC. (Simulation using 0.5 minute resolution)

Alert Date (UTC) Name Country Storm surge height (m)
12 Feb 2018 15:00 Ohonua Tonga  0.4
12 Feb 2018 16:00 Fuaamotu Tonga  0.3
12 Feb 2018 16:00 Fatumu Tonga  0.3
12 Feb 2018 14:00 Kolonga Tonga  0.2
12 Feb 2018 14:00 Niutoua Tonga  0.2
12 Feb 2018 16:00 Nukunuku Tonga  0.2
12 Feb 2018 16:00 Houma Tonga  0.2
12 Feb 2018 16:00 Pea Tonga  0.2
12 Feb 2018 16:00 Nuku'alofa Tonga  0.2
12 Feb 2018 14:00 Mua Tonga  0.2
12 Feb 2018 17:00 Foui Tonga  0.2
09 Feb 2018 13:00 Fuailalo Samoa  0.2
09 Feb 2018 14:00 Fasitootai Samoa  0.1
09 Feb 2018 15:00 Saleimoa Samoa  0.1
09 Feb 2018 15:00 Lotofago Samoa  0.1
09 Feb 2018 12:00 Salailua Samoa  0.1
09 Feb 2018 14:00 Puapua Samoa  0.1
09 Feb 2018 13:00 Tuasivi Samoa  0.1
09 Feb 2018 14:00 Samatau Samoa  0.1
09 Feb 2018 14:00 Faleaseela Samoa  0.1
09 Feb 2018 12:00 Sasina Samoa  0.1
09 Feb 2018 12:00 Leagiaga Samoa  0.1
09 Feb 2018 13:00 Gautavai Samoa  0.1
09 Feb 2018 12:00 Fagamalo Samoa  0.1
09 Feb 2018 13:00 Satupaitea Samoa  0.1
09 Feb 2018 15:00 Amaile Samoa  0.1
09 Feb 2018 01:00 Mua Wallis and Futuna  0.1
09 Feb 2018 01:00 Mata-Utu Wallis and Futuna  0.1
09 Feb 2018 11:00 Hihifo Tonga  0.1
09 Feb 2018 11:00 Falehau Tonga  0.1
09 Feb 2018 11:00 Falealupo Samoa  0.1
09 Feb 2018 12:00 Falelima Samoa  0.1
09 Feb 2018 13:00 Salelologa Samoa  0.1
09 Feb 2018 13:00 Utuavanua Samoa  0.1
09 Feb 2018 14:00 Matautu Samoa  0.1
09 Feb 2018 14:00 Siumu Samoa  0.1
09 Feb 2018 13:00 Apia Samoa  0.1
09 Feb 2018 14:00 Poutasi Samoa  0.1
09 Feb 2018 14:00 Solosolo Samoa  0.1
09 Feb 2018 17:00 Poloa American Samoa  0.1
09 Feb 2018 17:00 Amanave American Samoa  0.1
09 Feb 2018 17:00 Seetaga American Samoa  0.1
09 Feb 2018 17:00 Fagamalo American Samoa  0.1
09 Feb 2018 17:00 Amaluia American Samoa  0.1
09 Feb 2018 17:00 Leone American Samoa  0.1
09 Feb 2018 17:00 Vailoatai American Samoa  0.1
09 Feb 2018 17:00 Taputimu American Samoa  0.1
09 Feb 2018 17:00 Futiga American Samoa  0.1
09 Feb 2018 17:00 Pavaiai American Samoa  0.1
09 Feb 2018 17:00 Vaitogi American Samoa  0.1
09 Feb 2018 17:00 Iliili American Samoa  0.1
09 Feb 2018 17:00 Mesepa American Samoa  0.1
09 Feb 2018 17:00 Faleniu American Samoa  0.1