EC has issued its first winter storm watch of the season for the Red River valley, Interlake and SW MB areas. A storm system intensifying over the Dakotas Thursday will spread an area of rain over southern MB through the day Thursday that will change to snow over higher elevations west of the Red River valley. Rain will change through a period of ice pellets and possible freezing rain along the Red River valley Thursday evening before changing to all snow Thursday night. The transition to snow will be slowest southeast of Winnipeg which will keep snow amounts down in those areas. Snowfall totals with this system will be tough to forecast given the uncertainty in timing and location of the rain/IP/snow line, terrain effects, pcpn rate intensity (which can affect rain/snow transition), as well as melting effects of the still warm ground. At this point, preliminary snowfall accumulations by Friday could range from trace-2 cm over SE MB, 5 cm over Red River valley including Winnipeg (perhaps 10 cm north and west of the city into the southern Interlake), and 10-15 cm along the western red River valley/SW MB areas with the highest amounts over higher elevations. Stay tuned for further updates on this developing situation..