A developing low near the north coast will result in a pooling of Arctic air over the north today as winds strengthen. Meanwhile the jet stream will spread Pacific moisture across the southern half of the province. Increasing westerly flow will allow freezing levels to rise to as much as 1600 metres ahead of the low. Tonight the low will advance toward the central interior and snow levels will begin dropping as upslope northerly flow strengthens north of the trough.
Heaviest snow is expected to be from the Williston through the northern Rockies with up to 30 cm possible through Sunday. On Sunday the arctic front will continue to advance as the moisture becomes more extensive over the south and the Northern Rockies. Snow levels meanwhile begin to drop over the southern mountain passes and snow will accumulate.
The CMC runs are not as deep with the upper low feature as previous runs and are more in tune with the other models now. Although the GFS seems a little too progressive after 36 hours with a deeper surface low further to the east. The pattern is shaping up though to be a stronger push of arctic air then the previous one a couple of weeks ago. Consequently more snow is expected with this system over a larger area. Some snow is likely down to near sea level on the south coast on Monday as snow levels drop with the upper low dropping into western Washington. A northerly flow is expected to spread over the regions in the wake of the low giving drier but cold conditions into at least the middle of the week.