A freezing rain warning now covers a significant portion of eastern Ontario and southern Quebec, with Environment Canada saying a “prolonged period” of freezing rain, potentially lasting up to 24 hours, could affect the region this week. An orange warning for freezing rain has been issued, which means a high level of impact. Between 10 and 20 millimetres of freezing rain and ice buildup is expected, according to the weather warning. “A series of low pressure systems will lead to significant freezing rain across parts of southern Ontario. Freezing rain may fall heavily at times. In this case, the precipitation may not freeze immediately, which may lead to localized flooding in low lying areas,” Environment Canada says. “Roads and walkways will likely become icy and slippery. There may be a significant impact on rush hour traffic. Prolonged utility outages are likely. Significant damage to property, including some buildings and trees, is likely due to the weight of ice.” During a media availability Tuesday, warning preparedness meteorologist Eric Tomlinson compared the coming system to the April 2023 ice storm. The warning for eastern Ontario affects areas including but not limited to Ottawa, Pembroke, Renfrew, Kemptville, Smiths Falls, Perth, Cornwall, and Hawkesbury and the surrounding areas. City of Ottawa declares ‘significant weather event’ The City of Ottawa says it has declared a “significant weather event” for Wednesday, to give road crews time to deal with the storm. “The Roads and Parking Services team will be out maintaining the City’s sidewalks, roads and the winter cycling network, but it will take longer than usual to restore them to regular conditions,” the City of Ottawa said in an announcement Tuesday afternoon. “Please exercise caution when using City sidewalks, roads and the winter cycling network. Freezing rain will make surfaces icy and could lead to power outages. Please prepare accordingly and avoid unnecessary travel.” The city says it does not anticipate issuing a parking ban. Hydro Ottawa is urging residents to be prepared for power outages. “Ice buildup on trees and power lines can cause branches to snap and lead to potential power outages. Our crews are on standby and ready to respond safely and as quickly as possible should the lights go out,” Hydro Ottawa said on social media. “How you can prepare: Ensure your cell phones and power banks are fully charged. Check your emergency kit: Make sure you have flashlights, fresh batteries, and a 72-hour supply of water and non-perishable food.” In the event of a prolonged power outage, officials are reminding residents not to heat homes with inappropriate appliances such as outdoor grills, or to operate generators indoors, even if areas are ventilated, as it could lead to a buildup of carbon monoxide. Since the buildup of ice could lead to broken tree branches, it is recommended to move vehicles out from under trees whenever possible. “The saturated or frozen ground will have little ability to absorb this rainfall,” the statement says. “Heavy downpours may cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible.” OC Transpo OC Transpo says preparations are underway to keep public transit operating safely for riders during the storm. A memo from interim general manager of transit services Troy Charter to members of council says O-Train Line 1 will operate every four to five minutes during the morning commute. The number of trains may be adjusted to mitigate ice buildup on overhead wires and tracks, Charter says. “This frequency will also allow for flexibility should additional adjustments be required. RTM has applied de-icing fluid to the overhead wires to help reduce ice buildup and will be running trains with special pantographs to help scrape ice off the wires as the vehicles pass by,” he says. O-Train Line 2 and 4 will operate as regularly scheduled. “TransitNext has deployed additional resources to monitor switches and keep platforms and train doors clear of ice,” Charter says. Buses and ParaTranspo will continue to operate but road conditions may impact traffic and lead to longer travel times. Riders are being advised to allow more time when planning their commute and to use caution when boarding and exiting at bus stops or stations. Significant weather event in Renfrew County The County of Renfrew has declared a “significant weather event” in advance of the storm. “A Significant Weather Event means an approaching or occurring weather hazard with the potential to pose a significant danger to users of the highways within the municipality. This declaration suspends the standard timelines required for municipalities to meet their winter maintenance objectives until the municipality declares the Significant Weather Event has ended,” a news release issued Tuesday afternoon said. “The County of Renfrew wishes to note that the declaration of a Significant Weather Event is not notice of a reduced level of service or a road closure. The declaration is to notify the public that due to the current or forecasted conditions, caution is to be observed when travelling on Renfrew County roads and that it may take longer than usual to bring the condition of the roads back to a state of repair.” Along the St. Lawrence Places closer to the St. Lawrence River might see less freezing rain, as the temperature could rise above the freezing mark Wednesday afternoon. A special weather statement for areas such as Brockville and Prescott includes periods of freezing rain with ice accretion or build up of 2 to 5 mm and rainfall amounts of 20 to 40 mm. In the Kingston and Belleville areas, a special weather statement says the area could see 20 to 40 mm of rain, with potentially higher amounts in the event of thunderstorms. ‘Potentially critical’ event in Quebec Further north, the Outaouais region of Quebec could see up to 30 mm of freezing rain in what Environment Canada is calling a “potentially critical” event. An orange warning for freezing rain covers much of southern Quebec. “The event could last up to 24 hours and paralyze some services,” Environment Canada says. “Conditions will remain cold in subsequent days, which may complicate and delay the full return to normal services.” Affected areas include Greater Montreal, Montérégie, Outaouais, Lanaudière, Laurentians, Parc du Mont-Tremblant, Mauricie, Drummondville and Quebec City, Environment Canada says. The City of Gatineau is asking residents to avoid travel as much as possible. “Travel should be undertaken before or after the freezing rain event. If travel is unavoidable, ensure you have an emergency kit in your vehicle, including warm clothing and blankets,” a news release says. The city says salting operations will begin before the start of precipitation on main roads and collector streets. Operators will begin spreading salt on local streets and sidewalks only once the primary network is secured. The City of Gatineau says the most critical period is expected between 10 a.m. and 6 p.m. Wednesday. This comes after a brief spring-like reprieve from the winter. Ottawa saw a high of 15 C on Monday, making it the warmest day of the year so far, and an above-average high is in the forecast for Tuesday. Ottawa forecast The current forecast calls for a 40 per cent chance of rain showers or drizzle this evening and after midnight. The low is -2 C. Freezing rain is expected to begin early Wednesday morning, with the temperature steady near zero for most of the day. Freezing rain or rain are in the forecast for Wednesday evening. Thursday’s forecast for Ottawa calls for a high of 0 C with a 60 per cent chance of flurries. Periods of snow are in the forecast for Friday, with a high of-3 C.