textproduct: Twin Cities

KEY MESSAGES

- MAJOR WINTER STORM THIS WEEKEND will bring heavy snow across the region Saturday evening through Sunday. Dangerous to impossible travel conditions are expected. An areawide Winter Storm Warning has been issued.

- SNOW AMOUNTS: High confidence in a widespread swath of 8"+ of snow across the Winter Storm Warning locale. It's likely that most locations observe snowfall totals between 10-16", with a narrow band of heavier snow amounts approaching 20". (SE MN into western WI).

- BLIZZARD CONDITIONS are possible across southwestern MN Sunday as northerly winds increase. Peak gusts of 40-50 mph expected.

- HISTORICAL CONTEXT: We have included a list of the largest snowfalls in the Twin Cities in the Climate section below the forecast discussion.

DISCUSSION

Issued at 320 PM CDT Fri Mar 13 2026

REST OF TODAY/TONIGHT...Potent ~980s mb Pac Low that produced incredible synoptic winds overnight (Multiple 60-70 mph gusts observed!) is quickly exiting to the east over the Great Lakes. Northwesterly winds have weakened substantially since last night, though 20-30 mph gusts are likely to persist through the afternoon. Quiet weather returns tonight as the pressure gradient relaxes with the approach of an area of high pressure this evening. No major weather concerns tonight, though focus will shift to southwest MN towards daybreak as an initial warm advective band of light snow begins to take shape. Minor snow accumulations are possible across far southwestern MN by daybreak.

MAJOR WINTER STORM THIS WEEKEND

OVERVIEW...A Winter Storm Warning has been issued for the entire WFO MPX forecast area Saturday afternoon/evening through daybreak Monday. A long duration heavy snow scenario is set to take shape as the trifecta of rich pacific moisture, gulf moisture, and a deepening surface low move across the Upper Midwest. Ensemble guidance continues to advertise a remarkable QPF footprint over the region (~1-1.75" liquid moisture from west to east across our forecast area!) which will translate to a wide swath of double digit snowfall amounts (10-16"). As the winter storm takes shape, a localized, narrow band of the most intense snowfall rates will set the stage for very heavy snow accumulations northwest of the surface low. Latest indications are that this band will setup across portions of SE MN into western MN along/near I-94 (including portions of the the Twin Cities Metro) and it's increasingly likely that peak snowfall amounts will approach 18-20" within the band. Dangerous travel conditions will develop Saturday night and worsen overnight into Sunday morning as rates increase. Northerly winds will intensify on Sunday, which will contribute to periods of blizzard conditions and may create a nearly impossible travel scenario. The major winter storm begins to exit Sunday evening, however travel conditions will likely remain dangerous into Monday as winds will remain elevated, prolonging blowing snow concerns.

TODAY'S FORECAST TRENDS...12z guidance has advertised a slight northward shift in the main swath of the heaviest snow owing to what appears to be a slightly deeper trough aloft which yields a stronger surface low taking a more northward track along the mid-level baroclinic zone. As has been the case several times this cool season, we're seeing what appears to be an over correction with a shift too far to the north in the long range CAM guidance (12z HRRR in particular). We'll continue to lean on legacy global ensemble means and the machine learning (AIFS/AIFS Ens) solutions, which have displayed a less notable northward shift that appears to be within the expected envelope of solutions. As a result, the axis of heaviest snow is now forecast along and near the I-94 corridor from the Twin Cities into western WI. Should these trends continue, we'll likely be looking at warm nose complications resulting in a wintry mix of snow/sleet and possible freezing rain during the first half of the event across far southern MN. While this scenario will cut into snow amounts along I-90, significant travel impacts will still be expected. Our primary forecast focus over the next 24-hours will be to monitor any shifts in the consensus track of the low/placement of the heaviest snow band.

METEOROLOGICAL OVERVIEW OF THE STORM...GOES-West Water Vapor imagery captures a shortwave slowly circulating over the Gulf of Alaska, nearing western British Columbia. South of the wave, water vapor displays a ribbon of rich Pacific moisture flowing into the northwestern CONUS. Evidence of the moisture transport can be seen this afternoon on regional radar displays over the western Dakotas, where the first signs of precipitation are ongoing north of a sprawled out baroclinic zone. Over the next 24-48 hours, the shortwave is progged to come ashore ahead of a powerful ~160kt jet streak aloft and deepen into a longwave trough over the central CONUS. The trough is progged to translate east and become negatively tilted over the Great Lakes by the end of the weekend. In response, lee cyclogenesis will occur over the western Plains Saturday and the translation of the upper trough will send the resultant surface low on a track from central IA to southern WI to central MI Sunday. Mid-level warm advection and isentropic ascent will support the development of a narrow frontogenic band of light snow extending into southwestern MN by Saturday morning. This band will gradually become more impressive and produce accumulating snow across western MN by late morning/early afternoon. By Saturday evening, stronger isentropic ascent will support top down saturation and the development of a more pronounced band of snow, with rates increasing as the surface low moves eastward into central IA. The low will deepen heading into Sunday and begin to pivot to the northeast following the aforementioned track during the day. Following the conceptual mid-latitude cyclone model, a heavy deformation band of precipitation will develop north/northwest of the surface low and will be the driver of intense precipitation rates. To little surprise, model forecast soundings within the heaviest band indicate strong omega forcing through the column in association with a deepening DGZ Saturday night into Sunday. Deeper analysis of model cross sections illustrate a strong upright instability signal -- all of which supports snowfall rates in excess of 2", to perhaps 3"/hr within the most intense period of the winter storm. And yes, this scenario supports mention of potential thundersnow early Sunday morning, which would be most likely within the region of strong frontogenesis across eastern MN/western WI.

While ensembles have been fairly consistent with the magnitude of the QPF footprint, event SLR's have been a bit tricky to dial in. Model SLR's have consistently advertised event ratios of 13-18:1, which is likely overdone for a few reasons... A local study conducted at WFO MPX found that SLR's are often capped around ~10:1 or so when heavy 6-hr QPF is in play, so we have tried to integrate this into our forecast grids. Of course, we're still talking about a major snow event with a large swath of 10-16" of snow...but wanted to dial back on the ratios a tad to try and get our Storm Total Snow forecast as close to reality as possible. As the surface low begins to cut to the ENE on Sunday, cold advection will increase and will support drier ratios running closer to 15-16:1 through the end of the event. Despite a roughly 5-7k DGZ depth Sunday afternoon, the other complicating factor for SLR's will be the increase in the wind fields through the column, which will likely fracture dendrites in some capacity. All of this to say that even after tempering SLR's a bit, we are still looking at the heaviest snowfall in a number of years!

BLIZZARD CONDITIONS POSSIBLE...Northerly winds will increase within the deformation zone/cold air advection regime as the low cuts northeast and deepens to ~980mb on Sunday. Forecast soundings across western and southern MN feature 40-50kt winds at the top of the column Sunday late morning/afternoon. The increase in winds signals noted visibility reductions and potential blizzard conditions Sunday. Snowfall rates will taper to ~0.5/hr as winds increase, however the expected drier snowflake character will be able to blow and drift more easily...so while there are some questions about the "mobility" of snow character earlier in the event, the increasing SLR should lead to an increase in blowing snow and blizzard concerns through the second half of the event. A future upgrade to Blizzard Warning may be needed across portions of south and western MN.

LOOKING AHEAD TO NEXT WEEK...Light snow gradually ends Sunday evening into early Monday as the system departs over the Great Lakes. Northwesterly synoptic winds will remain elevated through at least the first portion of Monday, which will likely prolong blowing snow concerns into the commute. Winds will gradually decrease as high pressure builds over the Upper Midwest in the wake of the winter storm Monday evening into Tuesday. Surface highs remain on the cooler side in the teens and 20s to open next week. However, warmer temperatures (40s) look to return for the middle to end of next week as large scale ridging expands east over the northern CONUS. While it's possible blended guidance is a little too warm given the fresh snowpack, confidence is medium to high that we'll begin the great melting cycle around the middle of next week.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 627 PM CDT Fri Mar 13 2026

The first mention of our impending winter storm has appeared in our 00z TAFs. Until then, some high and mid level clouds are expected overnight with winds continuing to diminish. Winds will be out of the southeast by tomorrow morning at 5-10kts. Clouds will increase but cigs will remain VFR until the very end of the period as our winter storm approaches. Have included MVFR cigs/vis for snow from 20-22z for Minnesota terminals. Winds will become easterly and increase with some gusts around 20kts.

KMSP...No concerns in the immediate term. Did go ahead and decrease cigs/vis with snow from 00z Sunday onward as confidence is high. Confidence is not quite high enough at 30-ish hours out to put prevailing LIFR conditions, so have included a PROB30 to cover this.

/OUTLOOK FOR KMSP/ SUN...LIFR/+SN. Wind NE 15-20G25-40kts. MON...Chance AM IFR BLSN. Wind NW 10-15 G30kts. TUE...VFR. Wind NW to S 5kts.

CLIMATE

Issued at 320 PM CDT Fri Mar 13 2026

To provide some historical context to the snowfall forecast for this weekend, here are the 10 largest observed single storm snowfalls in the Twin Cities recorded history (1884-present) as collected by the MN State Climatology office.

1. 28.4 inches: 1991 October 31 - November 3 (Halloween Blizzard) 2. 21.1 inches: 1985 November 29 - December 1 (Thanksgiving Weekend) 3. 20.0 inches: 1982 January 22 - 23 4. 17.4 inches: 1982 January 20 - 21 5. 17.1 inches: 2010 December 10 - 11 (Domebuster) 6. 16.8 inches: 1940 November 11 - 13 (Armistice Day) 7. 16.7 inches: 1985 March 3 - 4 (Largest March snowstorm) 7. 16.7 inches: 1940 March 10 - 14 9. 16.5 inches: 1982 December 27 - 28 10. 16.0 inches: 1917 January 20 - 21 10. 16.0 inches: 1999 March 8 - 9

MPX WATCHES/WARNINGS/ADVISORIES

MN...Winter Storm Warning from 10 PM Saturday to 7 PM CDT Sunday for Benton-Chisago-Douglas-Isanti-Kanabec-Mille Lacs- Morrison-Todd. Winter Storm Warning from 4 PM Saturday to 7 AM CDT Monday for Chippewa-Kandiyohi-Lac Qui Parle-Pope-Redwood-Renville- Stevens-Swift-Yellow Medicine. Winter Storm Warning from 7 PM Saturday to 7 AM CDT Monday for Anoka-Blue Earth-Brown-Carver-Dakota-Goodhue-Hennepin-Le Sueur-McLeod-Meeker-Nicollet-Ramsey-Rice-Scott-Sherburne- Sibley-Stearns-Steele-Waseca-Washington-Watonwan-Wright. Winter Storm Warning from 1 AM Sunday to 7 AM CDT Monday for Faribault-Freeborn-Martin. WI...Winter Storm Warning from 7 PM Saturday to 7 AM CDT Monday for Chippewa-Dunn-Eau Claire-Pepin-Pierce-St. Croix. Winter Storm Warning from 10 PM Saturday to 7 AM CDT Monday for Barron-Polk-Rusk.