Overall Green alert Tropical Cyclone for JOHN-18
in Mexico

Green alert for storm surge impact based on ECMWF source

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). However, the calculation for advisory number is not completed. Therefore, the latest available calculation is shown. All links, data, statistics and maps refer to the latest available calculation.


Population affected by cyclone-strength winds (>120km/h):No People
Saffir-Simpson Category: Tropical depression
Maximum sustained wind speed: 54 Km/h
he maximum Storm surge height is:  0.4m in El Golfo de Santa Clara, Mexico.

Storm surge

View animation and affected locations in an interactive map: open

Storm surge maximum height
Storm surge maximum height (Source: JRC)
Max windspeed
Max windspeed (Source: ECMWF)


people affected <=10000
people affected >10000 and <100000
people affected >100000

Calculation Alert color Date (UTC) Wind speed Population affected
TS CAT. 1 CAT. 2 CAT. 3 CAT. 4 CAT. 5 Countries
20180809.00 0 km/h (0 mph) No people
20180809.12 0 km/h (0 mph) No people
20180810.00 0 km/h (0 mph) No people
20180810.12 0 km/h (0 mph) No people
20180811.00 54 km/h (34 mph) No people

Affected locations

Alert Date (UTC) Name Country Storm surge height (m)
11 Aug 2018 22:45 El Golfo de Santa Clara Mexico  0.4
07 Aug 2018 21:45 San Felipe Mexico  0.4
09 Aug 2018 09:30 El Tornillal Mexico  0.3
07 Aug 2018 21:15 La Choya Mexico  0.3
07 Aug 2018 21:15 Puerto Penasco Mexico  0.3
06 Aug 2018 01:45 Tecomate Mexico  0.3
06 Aug 2018 01:45 Cabo Tepoca Mexico  0.3
10 Aug 2018 21:15 Del Monte Forest United States  0.3
10 Aug 2018 21:15 Pebble Beach United States  0.3
10 Aug 2018 21:15 Carmel Highlands United States  0.3
10 Aug 2018 21:15 Carmel-by-the-Sea United States  0.3
10 Aug 2018 21:15 Pacific Grove United States  0.3
10 Aug 2018 21:15 Carmel United States  0.3
10 Aug 2018 21:15 Monterey United States  0.3
Locations affected by Storm surge (15 of 350)
Calculation based on advisory number of 11 Aug 2018 00:00.
(Simulation using 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.

  • Interactive map: open

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