Winter storm warnings south, metro rides edge of snow

This is why meteorologists get prematurely gray.

Major uncertainties still exist for Twin Cities snowfall totals as models have yet to reach consensus. A much higher confidence forecast for heavy snowfall still remains for southern Minnesota and a good chunk of central Wisconsin. Here's the latest update on a powerful winter storm moving into the region Wednesday.

Storm headlines

• Winter storm warnings up for southern Minnesota for 6" to 12"+ snow totals.

• Winter storm watch remains in effect for Twin Cities metro.

• High confidence for heavy snow Wednesday for southern Minnesota.

• Low confidence remains for eventual metro snowfall totals.

• Most models show Twin Cities on edge of heavy snow to the south.

• European model continues to keep snow south of the Twin Cities.

INCLUDING THE CITIES OF...FARIBAULT...RED WING...ST JAMES...MANKATO...WASECA...OWATONNA...FAIRMONT...BLUE EARTH...ALBERT LEA

331 PM CDT TUE MAR 22 2016

...WINTER STORM WARNING IN EFFECT FROM 10 AM WEDNESDAY TO 9 AM CDT THURSDAY...

THE NATIONAL WEATHER SERVICE IN TWIN CITIES/CHANHASSEN HAS ISSUED A WINTER STORM WARNING FOR HEAVY SNOW...WHICH IS IN EFFECT FROM 10 AM WEDNESDAY TO 9 AM CDT THURSDAY. 

* TIMING...WEDNESDAY MORNING UNTIL THURSDAY MORNING.

* MAIN IMPACT...6 TO 12 INCHES OF SNOW. A FEW LOCATIONS COULD SEE MORE THAN 12 INCHES...ESPECIALLY ALONG INTERSTATE 90.

* OTHER IMPACTS...BLOWING AND DRIFTING SNOW WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT.

Here's the Twin Cities NWS latest thinking as of Tuesday afternoon.

The system

A major March snow storm deepens and moves into Minnesota Wednesday. There are still questions about precise storm track and eventual northern edge of the snow shield, but there's little doubt this will be a strong system for those who get the snow.

Southern Minnesota: Major winter storm conditions 

Let's start with the 'high confidence' forecast.

The well advertised major winter storm winds up and tracks east through Minnesota Wednesday. Snow spreads from west to east during the morning, and expands in coverage over eastern Minnesota and western Wisconsin during the afternoon. The main wave of rapidly accumulating heavy snow arrives Wednesday afternoon and Wednesday night.

The La Crosse NWS does a nice job of lying out the storm parameters for southeast Minnesota and Wisconsin.

Snow will come down hard for several hours in southern Minnesota. Snowfall rates could reach 1" to 3" per hour in the zone including Mankato, Albert Lea, Rochester, Northfield, Waseca, Owatonna, Winona, Red Wing and Eau Claire. Lightning and thundersnow are possible in the heavy snow corridor.

I'm inclined to agree with the Twin Cities NWS snowfall map below for southern Minnesota locations south of the Twin Cities. I'm still not sold on 3" to 6"+ totals for the metro core.

Twin Cities: Riding the edge of  the snow zone

NOAA's NAM 4 km model illustrates the forecast problem for the Twin Cities. This is one of the more "northerly" solutions for the inbound system, and it still paints a razor sharp snowfall cutoff right over the Twin Cities metro core. This model says 5" snowfall at MSP Airport with heavier totals in southeast metro towns like Lakeville, and close to zero in north metro towns like Maple Grove.  The heavy snow zone lays out along a Albert Lea-Rochester-Winona-Eau Claire line where over a foot could fall.

Euro: Storm stays south

Enter the usually trusty Euro model. The Euro is rock solid and steadfast insisting the storm's snow zone will stay entirely south of the Twin Cities. Not even a flake. Talk about boosting forecaster confidence. Somebody's gotta blink.

Honestly I've never seen such a clear cut difference on heavy snow vs. no snow for the metro. One thing to note. The Euro has just been recently upgraded. It did not handle last weekend's eastern snow event well.

Here's the still dry Tuesday afternoon Euro update for MSP. Look familiar?

Bottom line

Here are some bottom line takeaways for planning purposes Wednesday.

• Winter storm conditions with heavy snow are likely in southern Minnesota Wednesday into Thursday morning.

• Travel south of the Twin Cities will be impacted along the I-90 corridor, Highway 169, I-35, Highway 52, and I-94 eastbound.

• Snowfall totals of 6" to 12"+ are likely in southern Minnesota.

• The prudent forecast for the Twin Cities is to prepare for at least some snow Wednesday afternoon and evening.

• The highest chances for significant accumulation favor the south and east metro.

• A sharp snowfall cutoff over the metro will likely result in little accumulation in the north metro.

• Wednesday PM rush hour will likely be impacted by  falling snow.

• There is still a chance the storm could miss the Twin Cities entirely to the south.

Stay tuned for late night and early Wednesday model updates before the snow flies for real Wednesday afternoon and evening.