Storm surge forecasting

We combine capabilities in weather, storm surge and tide forecasting with tide gauge observations to predict sea levels for specific locations under forecast weather conditions.

Storm surge forecasting

At NIWA we combine capabilities in weather, storm surge and tide forecasting with tide gauge observations to predict sea levels for specific locations under forecast weather conditions. This capability is underpinned by our NIWA Forecast software.

Storm surge forecasts can alert you when sea levels pass a certain threshold, enabling you and your community to take steps to prepare for potential inundation. 

If you’d like to talk about this service for your location, get in touch using the contact details below.

How does NIWA forecast storm surge?

Our storm surge forecasts use local tide gauge observations to provide a forecast relative to a fixed datum or by mean sea level anomaly. 

Tide gauge data needs to be ingested into our system at near real time to be used – we currently do this for these sites. If you’re interested in installing a sea-level gauge or providing access to data from an existing gauge, get in touch. 

If there is no tide gauge at a location of interest, we can infer the mean sea level anomaly from nearby sites, although these may be less accurate.

We can also use data from existing LINZ/GNS tsunami gauges although these use pressure gauges for measurements and can drift over time.

Case study: Sumner, Christchurch 

NIWA currently provides a storm surge forecast service at Sumner Head for Christchurch City Council. 

In the forecast image below:

  • The blue line shows the forecast sea level 

  • The red dotted line shows observed sea level (as these observations become available).

  • The vertical dotted line indicates the point in time at which the screenshot was taken.

  • The green line shows observational data for Bridge Street, New Brighton (as a comparison.) Note that the amplitude of this curve is reduced and timing slightly delayed compared with the Sumner values due to effects from the estuary. These estuarine effects also cause the nonlinearity of the signal (saw tooth shape with steeper increase and slower ebb). The higher baseline for Bridge Street is due to the river input.

 

 

Contact

Hydrodynamics Scientist