GDACS is a cooperation framework between the United Nations, the European Commission and disaster managers worldwide to improve alerts, information exchange and coordination in the first phase after major sudden-onset disasters.

Overall Red alert Tropical Cyclone for GITA-18
in Tongafrom 09 Feb 2018 00:00 UTC to 14 Feb 2018 06:00 UTC
Storm surge for tropical cyclone GITA-18

Green alert for storm surge impact in New Caledonia

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.

This report is for advisory number 22 of tropical cyclone GITA-18 issued at 14 Feb 2018 6:00:00 (GDACS Event ID 1000436).


Current impact estimate:

  • Population affected by cyclone-strength winds (>120km/h): 80 thousand
  • Saffir-Simpson Category: Category 4
  • Maximum sustained wind speed: 231 km/h
  • The maximum Storm surge height is  0.3m in Gadji, New Caledonia. This height is estimated for 16 Feb 2018 12:00:00.


Previous calculations: see calculation for advisory number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Show forecast grid

Storm surge

View animation and affected locations in an interactive map: open

Storm surge maximum height
Storm surge maximum height (Source: JRC)
Storm surge animation
Storm surge animation (Source: JRC)

Affected locations

Date Name Country Storm surge height (m)
16 Feb 2018 12:00:00 Gadji New Caledonia  0.3m
16 Feb 2018 12:00:00 Wapan New Caledonia  0.3m
16 Feb 2018 11:00:00 Kuto New Caledonia  0.2m
16 Feb 2018 14:00:00 Vao New Caledonia  0.2m
16 Feb 2018 09:00:00 Plum New Caledonia  0.2m
16 Feb 2018 10:00:00 Prony New Caledonia  0.2m
16 Feb 2018 09:00:00 Saint-Louis New Caledonia  0.2m
16 Feb 2018 13:00:00 Tomo New Caledonia  0.1m
16 Feb 2018 08:00:00 Dumbea New Caledonia  0.1m
16 Feb 2018 08:00:00 Ouara New Caledonia  0.1m
16 Feb 2018 13:00:00 Nouville New Caledonia  0.1m
16 Feb 2018 13:00:00 Noumea New Caledonia  0.1m
16 Feb 2018 13:00:00 Comm. du Mont-Dore New Caledonia  0.1m
16 Feb 2018 02:00:00 Bouloupari New Caledonia  0.1m
Locations affected by Storm surge (15 of 18)
Calculation based on advisory number 22 of 14 Feb 2018 06:00:00.
(Simulation using 0.5 minute resolution)

See full locations list (RSS)

More information

The atmospheric forcing included in the storm surge model are the pressure drop and the wind-water friction. The effects of the short waves induced by the wind (wave setup) and the precipitations are not yet implemented in the model. The model has been validated mainly in areas of shallow water (Caribbean, Bay of Bengal). Results in other basins may be inaccurate.

For a full list of available products related to this event, please refer to the GDACS Resources page.