Storm Shifts North: Metro “Slop Storm”? St. Cloud & Duluth heavy snow!

Winter Storm Warnings kick in Tuesday

Blizzard Warnings for western MN & eastern Dakotas

Storm track shifts north - again!

Heavy snow band from Wheaton-Morris-Alex-St. Cloud-Brainerd-Duluth (8" to 16" possible!)

Mixed precip types looking more likely for the metro

Starting as snow in the metro Tuesday AM - mix to all rain PM/evening?

Heavy rain possible (Up to 1"+?) Tuesday evening from the metro south!

Localized street ponding & flooding Tuesday night in the metro and south

Good news for easing MN drought regardless of eventual precip types!

Northward Shift Holds:

**That's the main headline as we head into Monday evening. The northward shift I talked about in this morning's model runs has held firm in the PM (18Z) model updates.**

Local NWS offices have acknowledged the northward model shift, but are (understandably) reluctant to let the notion of heavy snowfall go for the greater Twin Cities...even as the Duluth office has expanded winter storm warnings northward to account for the northern track shift.

Here at the Weather Lab I'm leaning more towards a "snow sandwich" for the metro. Precip begins as snow Tuesday AM...changes to a mix Tuesday PM then all ran by Tuesday evening. It may go back to all snow by around 3am Wednesday, but by then a dry slot could shut off heavy precip, keeping snow totals down.

NWS seems to be betting on some "dynamic forcing" with intense precip rates that could keep precip mostly snow in the metro...and that could happen. But right now I'm just seeing too strong of a push of warm air above freezing in the lowest mile of the atmosphere to be overcome by drawing down colder air form aloft.

Honestly, I'm a little freaked out that NWS has not gone stronger toward the mostly rain solution fore the metro. Like they say in those PGA golf promos; "Those guys (and gals) are good."

I'm going to be looking again hard at my forecast tonight before the snow flies to see if there is a trend toward keeping mostly snow in the forecast for the metro. Right now I appear to be the outlier on the low side of snow forecast totals, leaning more toward mostly rain.

Time will tell.

Here the latest breakdown of the system pending tonight's final model runs before the snow starts to fly!

Track:

The system has shifted track again to the north, supporting Monday AM model trends. 24 hours ago some models tracked the surface low through northern Iowa. Now the GFS and NAM agree on a track from Sioux Falls to the Twin Cities.

Timing:

Expect snow to break out after midnight tonight in southwestern Minnesota and work east. The GFS brings snow into the metro by sunrise, the NAM holds off until later Tuesday AM.

Precip type:

It looks like all snow at the onset of this event. Snow will begin to pile up early Tuesday morning in western and central Minnesota and continue all day.

In the metro, snow should begin in the morning and stay all snow until afternoon.

By Tuesday 2-4PM there should be a changeover from snow to mixed precip (sleet?) from the metro south... and then a gradual change to all rain later in the afternoon.

Heavy rainfall?

There are indications that the heaviest precip may fall as rain from the Twin Cities south at the height of the storm Tuesday night.

The NAM is cranking out as much as 1.5" of rain in the metro and south along I-35 Tuesday night!

If that happens, there will likely be localized street flooding and ponding of water from rain & snow melt in the metro and south Tuesday night.

Snowfall totals:

As you would expect, the northern track shifts the heaviest snow band to the north.

Right now it looks very likely that the heaviest snow band (all snow for the duration of the event) will run from west central Minnesota (Browns Valley, Wheaton Ortonville & Morris) through central Minnesota (Alex, St. Cloud, Mille Lacs, Mora) into north central Minnesota (Brainerd, Hinckley, and Duluth.)

In these areas anywhere from 6" to 12"+ is likely, with some totals possibly up to or exceeding 18"!

NAM confirms northward snow trend.

In the metro I am expecting a shot of 1" to 3" of snow Tuesday morning before the changeover to sleet/rain. We may pick up another inch or so on the back side of the system Wednesday.

Overall I would say a range of 1" to 4" looks likely for the metro, with the best chance of 4" in the northwest metro. (Anoka, Maple Grove, Buffalo) Snowfall totals should increase accordingly as you move up I-94 towards St. Cloud, where a foot of snow is quite possible.

If the warm air push is not as strong, or the track jogs south again in tonight's model runs I may have to increase snowfall totals for the metro.

Needless to say, stay tuned to see what tonight's model runs do as things can still change!

Next update by around 11pm tonight!

PH