Significant snowfall of 15 to 25 cm tonight and Friday. A winter storm will affect the regions tonight and Friday. Snow associated with a trough ahead of this system has spread into South-Central Ontario with a couple cm of light snow expected in most areas this evening. However, a significant change is expected overnight. This Texas low will intensify into a major winter storm as it approaches Southern Ontario towards morning. An expanding area of heavy snow is expected to move into western parts of Southern Ontario near Lake Huron beginning late this evening then spread east across remaining regions overnight or early Friday morning. The heaviest snow will occur during the Friday morning rush hour along the highway 401 corridor from London across Waterloo region and the Greater Toronto area. Heavy snow will spread quickly east during the day to affect Kingston through Brockville to Cornwall. Strong and gusty northeasterly winds will whip up the freshly fallen snow and result in very low visibility at times in blowing snow. Total snowfall amounts of 15 to 25 centimetres are likely across the regions. Snowfall rates of 2 to 4 centimetres per hour are possible during the heaviest snow, and if this occurs, near zero visibility in the heavy snow may be a significant issue to deal with. Hazardous winter travelling conditions from near zero visibility, areas of heavy snow and local blowing snow are expected especially on Friday. Rapidly accumulating snow will also contribute to dangerous driving conditions. Travel plans should be changed accordingly. The snow will end in areas west of the Greater Toronto area in the afternoon, in the Toronto area in the evening and overnight in easternmost sections as the storm centre moves away.