A special weather statement is in effect for much of the Greater Toronto and Hamilton Area, with periods of rain and thunderstorms expected throughout the day and into the evening. Just before 6:30 am., Environment Canada issued the advisory the following areas: The national weather agency is warning of the possibility of up to 50 mm of localized heavy rainfall starting this morning. “Periods of rain and embedded thunderstorms are expected through this evening,” it said in the statement. “Localized heavy rainfall is possible for areas that receive multiple thunderstorms.” Environment Canada says rainfall warnings may also be issued. People should note that water will likely pool on roads and in low-lying areas and that visibility will likely suddenly reduced at times. Rainfall warning issued for parts of Niagara A yellow warning for rainfall was also issued at 3:47 a.m. on Sunday for Niagara Falls - Welland - Southern Niagara Region and St. Catharines - Grimsby - Northern Niagara Region. Localized heavy rainfall, exceeding 50 mm, is expected in those areas this morning and into the afternoon. “Locations impacted by multiple thunderstorms are expected to receive rainfall amounts in excess of 50 mm,” the agency said, noting the rain is expected to diminish from west to east later this afternoon. Environment Canada says water will likely pool on roads and in low-lying areas and some property damage could occur. “Don’t drive through flooded roadways. Watch for washouts near rivers, creeks and culverts,” it said. Residents are being urged to visit heir local conservation authority or the Ontario Ministry of Natural Resources for information concerning flooding. Flooding possible Early Sunday morning, Credit Valley Conservation (CVC) issued a flood outlook statement advising of “localized flash flooding and water pooling on the roads and in flood-prone and low-lying urban areas” in Peel Region. It noted, however, that flooding of the Credit River and its major tributaries is not expected. “Urban streams and rivers may be dangerous, especially in the vicinity of culverts, bridges, and dams. People are warned to stay away from all watercourses and to keep children and pets away,” CVC said. This statement is in effect through Monday or until further notice. Flood outlook statements are issued as an early notice of the potential for flooding based on weather forecast of heavy rain, snow melt, high wind or other conditions that could lead to high runoff, ice jams, shoreline flooding, or erosion. Anyone concerned about high water levels in their area should contact their municipality directly or call 911 for emergencies.