Twin Cities upgraded to winter storm warning

It’s here.

The season’s first significant winter storm has arrived. Snowfall spread across Minnesota on schedule Tuesday. Snowfall intensity will pick up as we move through the afternoon hours. The Twin Cities National Weather Service office has upgraded the greater Twin Cities area to a winter storm warning.

Including the cities of Monticello, Minneapolis, Blaine, St Paul, Stillwater, Chanhassen, Chaska, Victoria, Shakopee, Hastings, Hudson, and River Falls

1153 AM CDT Tue Oct 20 2020

...WINTER STORM WARNING IN EFFECT UNTIL 10 PM CDT THIS EVENING...

* WHAT...Heavy snow. Snow accumulations of 4 to 6 inches, with locally higher amounts.

* WHERE...Portions of west central Wisconsin and central and east central Minnesota.

* WHEN...Until 10 PM CDT this evening.

* IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the evening commute.

* ADDITIONAL DETAILS...As precipitation is ending, it may briefly change over to freezing drizzle, though minimal ice accumulations are expected.

Heavy snowfall rates

The heaviest part of the storm moves through the Twin Cities and southern Minnesota this afternoon. Snowfall rates in the heaviest snow bands will reach an inch per hour.

NOAA’s NAM 3 km resolution model shows the snow zone, with deeper blues depicting heavier snowfall rates this afternoon. Snow will taper off in the Twin Cities late Tuesday evening. Snow will taper off in northeast Minnesota after midnight.

Half a foot-plus in some locations

Much of central and southern Minnesota will pick up 3 to 6 inches of snow by late tonight. But a core of heavier snow is setting up from the Minnesota River in southwest Minnesota through the greater Twin Cities area. This morning’s forecast model runs crank out more than 6 inches, to as much as 9 inches locally across parts of the Twin Cities.

Here’s NOAA’s GFS snowfall solution.

Bottom Line

Expect snowfall rates to reach 1 inch per hour this afternoon in many areas. Roads will become slippery across much of central and southern Minnesota and afternoon rush hours look challenging for the Twin Cities.