Still on track: Major winter storm moves in Friday

The weather table is all set. Now we wait for the wintry guests to arrive.

All major forecast models still drive a major winter storm into Minnesota Friday and Saturday. Winter storm warnings cover most of Minnesota and parts of the Dakotas, Iowa and Wisconsin. Winter weather advisories are up for parts of 19 states.

Storm timing

The afternoon model runs still bring snowfall into southwest Minnesota Friday morning. Many models bring the leading edge of the snow shield into the Twin Cities around lunchtime. Snow spreads across northern Minnesota during the afternoon hours and may reach Grand Marais, Minn., by early evening.

NOAA’s NAM 3 km resolution model is typical of forecast model timing of snowfall across Minnesota.

Here’s the Twin Cities NWS timing chart.

Snowfall totals

It’s always interesting how focused people are on precise snowfall totals. That’s fun. But the impact of 6 or 7 inches of snow versus 9 inches is not that different. I still think most of Minnesota will end up with between 6 and 12 inches of snow from this system.

Snow to water ratios are likely to bracket around a 14:1 ratio. That should squeeze out an extra couple inches vs. a 10:1 snow to water ratio. And many locations will see 18 to 24 hours of accumulating snow. An average accumulation rate of .5 inch per hour would yield 9 inches to 12 inches in many areas.

Blowing snow Saturday

I really like this NWS Twin Cities depiction of the different weather conditions Friday and Saturday.

Travel may be more difficult Saturday even though many places will see heavier snowfall rates Friday afternoon into evening.

Model consensus

It’s interesting the forecast models have been so consistent with this storm. That’s encouraging and a little scary for forecasters.

What could possibly go wrong?

Stay tuned.