Storm Corin is forecast to bring its strongest winds and heaviest rain to Port Avalon overnight on Monday, peaking around the 3am high tide on Tuesday.
That timing matters more than the wind speed. A storm surge on a low tide is a nuisance; the same surge on a high tide can push water over the eastern seawall, which stands 9.5 feet above the harbour datum.
Storm Corin at the eastern seawall
Forecast water level at the Tide Street gauge, with wind and rain, every three hours. Drag the slider or press Play.
- Time
- Tue 3am
- Wind
- 61 mph
- Rain
- 1.6 in/hr
- Water level
- 10.3 ft
Overtopping by 0.8 ft
Show the forecast
| Time | Wind (mph) | Rain (in/hr) | Water level (ft) |
|---|---|---|---|
| Mon 6am | 18 | 0 | 4.1 |
| Mon 9am | 22 | 0.1 | 5.6 |
| Mon noon | 27 | 0.2 | 6.4 |
| Mon 3pm | 33 | 0.3 | 5.2 |
| Mon 6pm | 38 | 0.5 | 5.9 |
| Mon 9pm | 45 | 0.8 | 7.6 |
| Tue midnight | 52 | 1.2 | 8.9 |
| Tue 3am | 61 | 1.6 | 10.3 |
| Tue 6am | 58 | 1.4 | 9.1 |
| Tue 9am | 49 | 0.9 | 7.4 |
| Tue noon | 40 | 0.6 | 7.9 |
| Tue 3pm | 31 | 0.3 | 6.6 |
| Tue 6pm | 24 | 0.1 | 5 |
The forecast puts the water about 0.8 feet over the top of the wall for roughly two hours either side of 3am. The city has moved pumps to Tide Street and asked residents of the three streets nearest the wall to move cars to higher ground by Monday evening.
A wetter autumn than usual
Corin arrives at the end of an unusually wet season. Rainfall in August, September and October was well above the 30-year normal, so the ground and the storm drains have less room to spare.
The wall is overtopped more often
The eastern seawall was raised to its current height in 2024. Even so, the number of days a year when waves or tides go over the defences along that stretch of coast has risen steadily.
Days a year the eastern sea defences were overtopped
Any day when water came over the defences at the Tide Street gauge, 2000 to 2026.
Use the left and right arrow keys to read each value.
Show the data
| Year | Days overtopped |
|---|---|
| 2000 | 1 |
| 2001 | 0 |
| 2002 | 2 |
| 2003 | 1 |
| 2004 | 2 |
| 2005 | 3 |
| 2006 | 2 |
| 2007 | 3 |
| 2008 | 6 |
| 2009 | 3 |
| 2010 | 4 |
| 2011 | 4 |
| 2012 | 5 |
| 2013 | 4 |
| 2014 | 6 |
| 2015 | 5 |
| 2016 | 7 |
| 2017 | 6 |
| 2018 | 8 |
| 2019 | 9 |
| 2020 | 8 |
| 2021 | 10 |
| 2022 | 9 |
| 2023 | 12 |
| 2024 | 7 |
| 2025 | 11 |
| 2026 | 14 |
The dip in 2024 followed the new wall. By 2025 the count was climbing again.
How we made this: water levels are the harbour authority’s forecast for the Tide Street gauge, issued at 5am on Monday. Wind and rain are the weather office forecast for the same three-hour periods. All figures in this story are fictional, created for The Draft demonstration site.
