Storm Surges along the B.C. Coast
Introduction
Winter storms on the west coast of Canada bring
high water and waves to coastal regions. When
combined with high tides (especially King Tides) these conditions can
cause flooding and
erosion.
The British columbia Ministry of Environment has partnered with Canada's Department of Fisheries and Oceans to develop a storm surge
prediction system. The system uses an operational ocean
model already in use at the Institute of Ocean
Sciences in Sidney, B.C., and weather forecasts from Environment Canada and NOAA to calculate the difference between the predicted astronomical tide and actual sea surface height.
Storm surge forecasts are updated daily and are used by emergency management professionals on B.C.’s coast to prepare for and mitigate the risks of damaging storm and high tide events. Improving information and awareness about storm surges is also an important component of preparing B.C. for sea level rise.
Storm Surge Forecast System Information Portal
A new BC Storm Surge Forecast System portal was launched in 2011 to provide quick and easy access to storm surge model outputs and information. The website provides links to the animated map and charts generated by the Pacific Ocean Model driven by a 7-day weather forecast from NOAA and a 6-day forecast from Environment Canada. Daily storm surge forecast bulletins are also availabe for Point Atkinson, Victoria and Campbell River and are automatically updated each morning. Other information available through the portal includes the seasonal storm surge almanac, reports, photos and presentations. Notifications about storm surges and model updates can also be received by following @SurgeBC on Twitter.
Daily Forecast Bulletins
VICTORIA HIGH WATER BULLETIN (6-day forecast):
POINT ATKINSON HIGH WATER BULLETIN (6-day forecast):
CAMPBELL RIVER HIGH WATER BULLETIN (7-day forecast):
Almanac
The Almanac provides a summary of the marine environment of southern British Columbia as it relates to the upcoming season:
Model - Animated Map
The storm surge model predicts storm movement and the resulting sea surface heights (SSHs) for the coming week.
The map below (on the left) shows the Northeast Pacific Ocean (colours) and the West Coast of North America (white). The black dots correspond to American tidal stations listed in the Chart (on the right) - from Kodiak, Alaska to Crescent City, California. (Neah Bay is located on the Olympic Penninsula in Washington state, approximately 90km west of Victoria; while Cherry Point is located approximately 30km southeast of Vancouver).
Sea Surface Height (SSH) is indicated by colour. SSH can be negative (purple), zero (blue) or positive (green, yellow, red). SSH measures how much the water level is displaced, independent of the tide. In other words, if a 3m high tide coincides with a storm surge with a +20cm SSH, then the water level will be at 3.2m. On the other hand, if the storm surge has a negative SSH, the high tide will be reduced; or alternatively, if a storm surge with a high SSH (e.g. +60cm, red) reaches shore during low tide, it may go relatively unnoticed.
Storm surges are therefore the most pronounced -- and can cause the most damage -- when they coincide with high tides. The forecasting of these events is posted for Victoria and Point Atkinson (West Vancouver) in the Daily Reports above.
The Chart on the right plots (for each tidal station) the recently observed SSH in black and the predicted SSH for the following week in red.
To access the Storm Surge Model, click on the screenshot below.
Model - Instructions
The buttons below the map are used to control the model:
| START |
Go to frame #1 |
| END |
Go to the last frame |
| -1 |
Go one frame ahead |
| +1 |
Go one frame behind |
| > |
Play forward |
| < |
Play backward |
| [] |
Stop |
| play once |
plays the animation once from start to end |
| loop |
repeat animation in continuous loop |
| swing |
plays the animation forward then backward |
| speed +/- |
controls the frame rate (up/down) |
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