Highlights:

• Strong Wind Warning remains in effect for western Lake Erie and Lake St. Clair.
• Risk of erosion, shoreline damage and flooding this evening through Saturday.
• Potential for shoreline damage and flooding in Lighthouse Cove, this evening and overnight, similar to what was experienced on Monday.
• Potential for shoreline damage and flooding on south facing shorelines of Lake Erie, Friday and Saturday
• Rain in the forecast could aggravate flooding in shoreline areas and the downstream end of watercourses where they outlet into the lakes.

Message:

The weather forecasts have changed since yesterday when the last Flood Watch was issued and the strong winds and excessive rainfall expected today have been downgraded. However, the Strong Wind Warnings issued by Environment Canada remain in place due to strong winds forecast for both Lake Erie and Lake St. Clair this evening and lasting through Saturday. Winds out of the northwest are forecasted to begin rising this evening peaking somewhere between 30 and 35 km/hr with gusts of 50 km/hr around midnight. Winds are then forecasted to switch back to the west or southwest and stay between 25 and 30 km/hr throughout the day Friday. Overnight Friday, winds are forecasted to begin rising again, with winds speeds approaching 40 km/hr with gusts of 60 km/hr Saturday morning and remaining strong for the rest of the day.

These strong winds will produce water level fluctuations on Lake St. Clair this evening and overnight. In the Lighthouse Cove area, and shoreline areas east in Chatham-Kent, static water levels (i.e. before waves) are forecasted to rise around 6 cm. Waves on Lake St. Clair between 0.5 m and 1 m in height are forecasted. Saturday on Lake Erie, waves are forecasted to be between 1 and 1.5 m in height at time. Given that water levels have exceeded record highs on both Lake Erie and Lake St. Clair, these further rises in water levels increase the risks and may impact new areas previously not known to be at risk.

Rain forecasts for today have been downgraded. Last evening and overnight the region generally received less than 10 mm of rain and forecasts are calling for an additional 5 mm this afternoon and evening. Forecasts are still calling for additional 15 – 20 mm on Saturday with light rain on Sunday and more rain on Monday.

Throughout this period, strong winds will be driving waves onto our Great Lakes shorelines in Lakeshore, Chatham-Kent and Elgin County. There is a risk that wave action could damage shoreline protection works and cause erosion. Low lying areas and communities are also at risk of flooding. As the winds shift around over the coming days, different shoreline areas will be impacted to a greater or lesser extent. While winds are out of the northwest, this evening and overnight, greater impacts are expected on Lake St. Clair, including in the community of Lighthouse Cove and the western shoreline of Chatham-Kent. Based on forecasts, the flooding in Lighthouse Cove would be similar to what was experienced last Monday. While winds are generally out of the southwest, on Friday and Saturday, south facing shorelines will be at greater risk of flooding and shoreline damage including areas such as Erie Shore Drive, Rondeau Bay Estates and the high bluff areas along Lake Erie in Chatham-Kent and Elgin County. (Erieau and Shrewsbury are not expected to be impacted as greatly as they have been recently as strong east winds are not predicted.)

The rain in the forecast for Saturday could aggravate the flooding situation. The water level (and groundwater table) is so high in shoreline areas that the rain will have problems draining away and may lead to localized flooding. In addition, those watercourses that drain into the lakes are already very high in their downstream ends due to high lake levels. The additional rain has the potential to cause excess flooding from these watercourses. Shrewsbury would be a community particularly at risk from this, although other areas could be impacted too. The rain also has the potential to impact the downstream areas of the Thames River as well, which are already elevated due to high levels on Lake St. Clair. The rain, on top of elevated water levels, could cause the Thames River to raise enough to put water over the sidewalk in downtown Chatham.

People should take extra caution and avoid the shoreline and any waterways with elevated water levels. The waves on the lakes can be strong, and the shoreline and the banks of waterways can be slippery. There could also be hazardous debris within the waves and water which could be thrown onto the shoreline. Standing water can also present unseen hazards. Children and animals should be kept away from the water.

Officials will continue to monitor the situation and update this advisory if necessary.
This message will be in effect until June 17, 2019.
Message Contact: LTVCA Admin Office (519-354-7310) or Jason Wintermute (jason.wintermute@ltvca.ca)