Indications of heavier snow shifting north has prompted the National Weather Service to place the Twin Cities metro area in a winter storm watch. Further to the south, a winter storm warning has been issued.
Heavy snow is expected to move into southern Minnesota from west to east late Saturday night through Sunday afternoon. The highest snow totals being predicted by the NWS are in south-central to southeast Minnesota, where 5-8 inches could pile up.
Further north, the current forecast calls for 3-6 inches of snow in the Twin Cities, but the weather service warns that there are indications that totals could be higher (more on that further down in the blog), thus the winter storm watch.
In the snowfall map below, please note that the weather service says that if the northerly shift continues, the amounts on the map will need to be shifted north.
Another factor to watch if you live in far southwestern and south-central Minnesota is the possibility of a dry slot limiting snow totals, according to the Twin Cities office of the National Weather Service.
The dry slot and the northern shift are identified nicely in the 7 a.m. simulation from the HRRR model, which has the Twin Cities metro area getting a healthy amount of snow.
At 0.5 to 0.7 inches of precipitable moisture and a snow:liquid ratio of 13-15 inches of snow for 1 inch of liquid, that would equate to anywhere from 6-10 inches if the HRRR model is correct. For the sake of transparency, this is how much snow the HRRR model is suggesting could fall.
Of course, there is expected to be a very sharp cutoff on snow totals on the northern side of the storm, so it's entirely possible that locations just 20-30 miles apart could see significant differences in how much snow accumulates.
With the snow expected to begin in western Minnesota late Saturday night and arrive in the metro and eastern parts of the state between 2 a.m. and 4 a.m., don't be surprised if new warnings and snowfall maps are issued by the weather service. Check back for updates!