Highlights:

• Strong Wind Warning has been issued 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, Thursday afternoon through early Friday, worse than what was experienced on Monday.
• Potential for shoreline damage and flooding on south facing shorelines of Lake Erie, this evening through Thursday and Friday through Saturday.
• Rain in the forecast could aggravate flooding in shoreline areas and the downstream end of watercourses where they outlet into the lakes.

Message:

A Strong Wind Warning has been issued by Environment Canada due to strong winds in the forecast for both Lake Erie and Lake St. Clair starting this evening and lasting through Saturday. Winds between 25 and 40 km/hr with gusts up to 60 km/hr are predicted for this entire period. This evening southeast winds are predicted to rise and approach 30 km//hr with gusts of 45 km/hr. The winds are expected to stay strong and transition through the south and west on Thursday and ending up as northwesterly Thursday afternoon with wind speeds approaching 40 km/hr and gusts of 60 km/hr. On Friday winds are expected to switch back to the southwest and stay strong above 25 km/hr rising again to 35 km/hr with gusts of 50 km/hr on Saturday.

These strong winds will produce water level fluctuations on both Lake Erie and Lake St. Clair. On the Lake Erie shoreline, static water levels (i.e. before waves) could rise around 5 cm. On Thursday, when winds are out of the northwest, static water levels in the Lighthouse Cove area and shoreline areas east in Chatham-Kent could see water level rises of around 15 cm. Waves on the Lake Erie could be expected to reach between 1 and 1.25 m in height at times. Waves on Lake St. Clair could be expected to reach 0.5 to 1 m at times. 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 is associated with these strong winds and forecasts are calling for 25 to 35 mm of rainfall in total this evening through Thursday. Forecasts are then calling for an additional 20 mm on Saturday, and showers Sunday through Wednesday.

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 generally out of the south (southeast through southwest), which includes most of this period other than late Thursday and early Friday, south facing shorelines will be at greater risk of flooding and shoreline damage including areas such as Erie Shore Drive, Rose Beach Line, Wheatley, 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.) While winds are out of the northwest, on Thursday afternoon through early Friday, 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 expected to be worse than what occurred last Monday.

Rain in the forecast is expected to 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)