It looks like our all-time February snowfall record is about to be shattered.
All systems appear to “go” for another two rounds of snow for Minnesota this week. Forecaster and model confidence is high that two significant snow system will move into the Upper Midwest this week.
The big forecast question? Where will the heavy snow band with the potential weekend storm set up? There are still wildcards in storm track and snowfall potential with the weekend snow system.
It’s still early to be specific about snow predictions for any one spot in Minnesota by Sunday. But multiple forecast models now crank out anywhere from 10 inches to more than 20 inches of total combined snowfall from multiple systems across part of southern Minnesota by Sunday night.
Winter storm watch late Tuesday night through Wednesday. Watch zone basically runs east of a Mankato to Woodbury line. Looks like 3" to 6" around Twin Cities, with 4" to 8" possible from Albert Lea through Rochester, Red Wing, and Menomonie. Snowy Wednesday commutes! #mnwx pic.twitter.com/0XDIkaoiw1
— MPR Weather (@MPRweather) February 18, 2019
System No. 1 Wednesday
Wednesday’s inbound snow system looks about as close to a slam-dunk as there is. That still makes me nervous.
Snow begins in southern Minnesota around midnight Tuesday night and spreads north into the Twin Cities by the morning commute Wednesday.
Here’s the National Oceanic and Atmospheric Administration’s Global Forecast System model. Look familiar?
Most models suggest widespread 3 to 6 inches totals including the Twin Cities by Wednesday evening. The best chance of 4 to 8 inches lays out along and either side of an Albert Lea-Rochester-Red Wing in southern Minnesota, to Menomonie, Wis.
System No. 2 weekend snow system
The weekend snow system looks complex and potentially stronger. Most models suggest a two-phase system that would bring one wave of snow Friday, with a second wave Saturday into Sunday.
Multiple-part systems worry me. Too much can go wrong. It’s still too early to pinpoint the track of the weekend system. It could slide south of the Twin Cities. But all models crank up a big low-pressure system that dumps a band of heavy snow. Somewhere.
The Canadian model captures the notion of a two-part snow system this weekend. Note the southern track on the weekend system. That would lay out the heaviest snowfall across southeastern Minnesota, south of the Twin Cities.
How much snow?
So how much will we get by Sunday night? This is where forecast confidence for any on town drops. Wednesday’s system pictured above looks solid. I’m less confident about the eventual track of the weekend system.
So take the images below with a big grain of salt. At this point, at least half of these overall snowfall totals depend on the eventual track of the weekend system. A lot can and probably will change.
Here’s the Canadian model forecast total snowfall at a 10:1 snow:water ratio by Sunday night. It suggests as much as 14 inches in southwest Minnesota with about 11 inches for the Twin Cities.
Here’s NOAA’s latest GFS model run. Closer to 15 inches in the Twin Cities and a 2-foot bull’s-eye in southern Minnesota.
Let’s watch and see not if, but how much these numbers change this week.