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 JOHN-18
in Mexicofrom 05 Aug 2018 21:00 UTC to 10 Aug 2018 12:00 UTC
Storm surge for tropical cyclone JOHN-18

Green alert for storm surge impact in Mexico

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 20 of tropical cyclone JOHN-18 issued at 10 Aug 2018 12:00:00 (GDACS Event ID 1000480).


Current impact estimate:

  • Population affected by cyclone-strength winds (>120km/h): Few people affected
  • Saffir-Simpson Category: Category 2
  • Maximum sustained wind speed: 167 km/h
  • The maximum Storm surge height is  0.1m in Agua del Coyote, Mexico. This height is estimated for 09 Aug 2018 19:00:00.


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

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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)
09 Aug 2018 19:00:00 Agua del Coyote Mexico  0.1m
Locations affected by Storm surge (15 of 1)
Calculation based on advisory number 20 of 10 Aug 2018 12:00:00.
(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.