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
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 10:00 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
Current 176 km/h 0.4 m n.a. 1.5
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) based on GDACS impact

Wind

176 km/h Current Max.

Up to 84000 people in Category 1 strength or higher (see SSHS)

Impact Timeline

Alert Date (UTC) Max Winds (km/h) Population in
Tropical Storm or higher
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
Orange 3 09 Feb 2018 12:00 148 930 thousand 80 thousand Tonga
Orange 4 09 Feb 2018 18:00 139 830 thousand 80 thousand Tonga
Orange 5 10 Feb 2018 00:00 139 820 thousand 80 thousand Tonga
Orange 6 10 Feb 2018 06:00 139 600 thousand 80 thousand Tonga
Orange 7 10 Feb 2018 12:00 130 670 thousand 80 thousand Tonga
Orange 8 10 Feb 2018 18:00 176 770 thousand 80 thousand Tonga

Bulletin Timeline

Alert Date (UTC) Category
(SSHS)
Max winds
(km/h)
Population in
Cat.1 or higher
Population in
Tropical Storm
or higher
Location (lat, lon) Countries
GREEN
1 09 Feb 2018 00:00 Tropical storm 74 no people 270000 people -13.8, -175.5 American Samoa
GREEN
2 09 Feb 2018 06:00 Tropical storm 74 no people 270000 people -14.3, -174.5 Niue
GREEN
3 09 Feb 2018 12:00 Tropical storm 83 no people 250000 people -14.5, -173 Niue
GREEN
4 09 Feb 2018 18:00 Tropical storm 83 no people 250000 people -15.3, -171.4 Niue
GREEN
5 10 Feb 2018 00:00 Tropical storm 93 no people 210000 people -16.1, -170 Niue
GREEN
6 10 Feb 2018 06:00 Tropical storm 93 no people 1200 people -17, -169 Niue
GREEN
7 10 Feb 2018 12:00 Tropical storm 102 no people 1200 people -18.2, -168.5 Niue
GREEN
8 10 Feb 2018 18:00 Category 1 139 no people 1200 people -18.9, -168.6 Niue
GREEN
8 11 Feb 2018 06:00 Category 2 157 no people 16000 people -20.3, -169.5 Niue
GREEN
8 11 Feb 2018 18:00 Category 2 167 no people 110000 people -21.1, -171.6 Niue
ORANGE
8 12 Feb 2018 06:00 Category 2 176 83000 people 110000 people -21.1, -174.2 Tonga
GREEN
8 12 Feb 2018 18:00 Category 3 185 <1000 people 500000 people -21.1, -176.8 Fiji
GREEN
8 13 Feb 2018 18:00 Category 2 176 no people 380000 people -21.5, 178.7 Fiji
GREEN
8 14 Feb 2018 18:00 Category 2 167 no people <1000 people -22.9, 175.2
GREEN
8 15 Feb 2018 18:00 Category 2 157 no people no people -24.9, 171.8
Actual track of the current bulletin
The alert for forecast greater than 3 days is limited to Orange level.
Download:



Exposed population - AoIs

Exposed population in the potential affected countries, provinces and populated places

Countries

Country
Tonga

Provinces

Region Province Country
Tonga Tonga

Populated places

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

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)
Eua Kaufana EUA unknown 0
Fua'amotu International TBU 38 Civ. Paved Yes 8700
Ono-I-Lau ONU unknown 0

Ports

Name LOCODE Country
Eua Island Tonga
Nuku'alofa TOTBU Tonga

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 Mua, Tonga. This height is estimated for 12 Feb 2018 10:00 UTC .

The JRC has developed an experimental global storm surge model. 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 (13 locations). Calculation based on advisory number 8 of 10 Feb 2018 18:00:00 UTC. (Simulation using 0.5 minute resolution)

Alert Date (UTC) Name Country Storm surge height (m)
12 Feb 2018 10:00 Mua Tonga  0.4
12 Feb 2018 10:00 Kolonga Tonga  0.4
12 Feb 2018 10:00 Niutoua Tonga  0.4
12 Feb 2018 12:00 Nukunuku Tonga  0.4
12 Feb 2018 12:00 Houma Tonga  0.4
12 Feb 2018 12:00 Pea Tonga  0.4
12 Feb 2018 12:00 Nuku'alofa Tonga  0.4
12 Feb 2018 12:00 Foui Tonga  0.4
12 Feb 2018 12:00 Fuaamotu Tonga  0.4
12 Feb 2018 12:00 Fatumu Tonga  0.4
12 Feb 2018 11:00 Ohonua Tonga  0.3
09 Feb 2018 01:00 Mua Wallis and Futuna  0.1
09 Feb 2018 01:00 Mata-Utu Wallis and Futuna  0.1