According to which weather service? Everything I've seen says today is the bad day.
Everything I read mentioned the storm would hit in two waves. These were both in the news Tuesday mid-afternoon.
"On Thursday, snow will begin to re-intensify over the region. Heavy snow will move westwards out of Ontario back across southern Manitoba. It looks likely that snowfall rates over the Red River Valley, including Winnipeg, will be more intense than previously forecast. This is a dynamic and rapidly evolving system; check local forecasts will be updated as required through the day.""
source: Environment Canada
"Thursday:
This is going to be ugly. The storm is in full throttle and northwest winds are strong.
The Colorado Low stalls over Minnesota, keeping Manitoba in its sights the entire day and into Friday.
Temperatures drop so the snow is not as sticky and heavy. Highs will be about –5 C compared to the normal high of 10 C for this time of year.
A further 15-20 cm is likely in the Winnipeg area."
source: CBC
I'm just getting up & it appears Winnipeg didn't get hit overnight like some other areas have. Let's keep in mind this is a rather large storm so I'm not surprised forecasters appear to have dropped the ball on where it would all fall.