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 Green alert Tropical Cyclone for DAHLIA-17
in Indonesia, Christmas Islandfrom 30 Nov 2017 00:00 UTC to 03 Dec 2017 18:00 UTC
Storm surge for tropical cyclone DAHLIA-17

Green alert for storm surge impact in Indonesia

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 16 of tropical cyclone DAHLIA-17 issued at 3 Dec 2017 18:00:00 (GDACS Event ID 1000423).


Current impact estimate:

  • Population affected by cyclone-strength winds (>120km/h): No people affected
  • Saffir-Simpson Category: Tropical storm
  • Maximum sustained wind speed: 102 km/h
  • The maximum Storm surge height is  0.2m in Semarang, Indonesia. This height is estimated for 02 Dec 2017 01:00:00.


Previous calculations: see calculation for advisory number 6 7 8 9 10 11 12 13 14 15 16

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)
02 Dec 2017 01:00:00 Semarang Indonesia  0.2m
02 Dec 2017 01:00:00 Jepara Indonesia  0.2m
02 Dec 2017 01:00:00 Bugel Indonesia  0.2m
02 Dec 2017 01:00:00 Karanggondang Indonesia  0.2m
02 Dec 2017 00:00:00 Sidaju Indonesia  0.1m
02 Dec 2017 00:00:00 Aermata Indonesia  0.1m
02 Dec 2017 01:00:00 Sungaitulak Indonesia  0.1m
02 Dec 2017 01:00:00 Karangroto Indonesia  0.1m
02 Dec 2017 02:00:00 Padangtikar Indonesia  0.1m
02 Dec 2017 08:00:00 Pagatan Indonesia  0.1m
02 Dec 2017 02:00:00 Doesoen Besar Indonesia  0.1m
02 Dec 2017 02:00:00 Sungaibuaja Indonesia  0.1m
02 Dec 2017 01:00:00 Siduk Indonesia  0.1m
02 Dec 2017 00:00:00 Wedung Indonesia  0.1m
Locations affected by Storm surge (15 of 25)
Calculation based on advisory number 16 of 03 Dec 2017 18:00:00.
(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.