textproduct: Twin Cities

KEY MESSAGES

- Strong system to bring an intense and narrow band of heavy snow this afternoon and evening along and north of the I-94 corridor. The rain/snow line looks to setup over the Twin Cities metro, with a strong snowfall gradient expected from southwest to northeast across the metro.

- A 2-4 hour period of freezing rain/drizzle will be possible along and just south of the I-94 corridor as precipitation initially moves in today.

- Strong winds are expected Tuesday evening southwest of the low track, with gusts of 40-50 mph possible south I-94 in Minnesota. Uncertainty remains high with how blowable the snow pack in southwest Minnesota will be after they see highs above freezing with rain and drizzle today.

- Multiple bouts of light snow will be possible Wednesday through Saturday. Only minor accumulations would occur with any additional snowfall we see after today.

- Very cold temperatures settle in by this weekend with wind chills approaching advisory criteria Friday night and Saturday night.

UPDATE

Issued at 1048 AM CST Tue Dec 9 2025

As of 10AM this morning, our sfc low which is driving today's wintry mess was located in northwestern North Dakota and moving east-southeastward. The forecast remains on track with the eastern periphery of the precipitation shield now making its way into western MN. Light snowfall rates this morning will increase to 1.0-1.5"/hour, especially along and north of the I-94 corridor as early as 2 to 3 PM this afternoon and persisting through the evening commute. Farther to the southwest, including the Twin Cities metro, a short period of freezing rain mainly between 2-4 PM is expected to occur prior to transitioning to all snow after 6 PM. Across SW'rn MN, cold rain will transition to freezing drizzle this evening and then change over to all snow tonight. With wind gusts approaching 50 to 55 mph, potential blowing snow could make traveling very difficult.

DISCUSSION

Issued at 320 AM CST Tue Dec 9 2025

As one clipper exits stage right over Lake Superior, the next one as already queued up just off stage. Water vapor imagery shows a deep plume of moisture coming off the northeast Pac and across the Can/US border into the Dakotas. Within this plume of moisture, a shortwave currently over southern Albert deepen and dig south through the day. This is what will result in the deepening surface low moving across MN this afternoon/evening. Spread remains higher than normal in the models for being within 24 hours of storm onset with the eventual track of the surface low. In a broad sense, we have a southern camp and a northern camp. The southern camp is where you will find the majority of your traditional deterministic models (GFS, ECMWF, Canadian...), ensemble systems, and AI driven models. The northern camp is almost being completely driven by CAMs (HREF). For this update, we continue to favor an ECMWF AIFS/EPS solution, with not much weight put into the northern, CAM driven solution. The biggest reason for this is recent verification, with the AIFS in particular performing very strong in correctly placing where heavier precip swaths end up going back to the pre-Thanksgiving winter storm. The resulting forecast is still very complex, with a threat for an initial burst of freezing rain, heavy snow this evening, then strong winds and potential for blizzard conditions tonight.

Initially this morning, we will have to deal with some very minor freezing drizzle with saturated low levels that are experiencing lift from WAA. There have been lots of BR (mist) reports from the airports overnight, which is a classic freezing drizzle signal, which is what the human observes have been noting all night at MSP. This bout of freezing drizzle will diminish when a location sees winds switch to the northwest, which will cutoff the WAA, at least momentarily. Precipitation will be moving quickly into western MN by the late this morning. As this band of WAA driven precip moves in, warm noses in soundings confirm what we are seeing with model p-type depictions, with a 2-4 hour window at precipitation onset where the predominate p-type will likely be freezing rain basically along and just south of the I-94 corridor. Although any ice accumulations are minor, there is some higher end potential out toward Alexandria and Glenwood in northwest portions of our CWA where ice accumulation over a tenth of an inch will be possible. After this initial burst of precipitation, it becomes a rain or snow question based on surface temperatures. Given it's heavy inclusion of CAMs, the NBM looks too aggressive with how far northeast it drives the freezing line this afternoon/evening and we used hourly temperatures from the GFS to help suppress this warm nose from the NBM. This resulted in a rain/snow line basically setting up from Glenwood, to Minneapolis and Durand in western WI. Besides the warm temperatures, the I-94 corridor will also be about where the mid-level dry slot terminates, so not only does the I-94 corridor have to deal with uncertainty in terms of the thermal environment on p-types, but there will be issues with cloud ice being present as well. The highest snow totals are expected to fall just north of where the freezing line and termination of the mid-level dry slot ends up, which right now would place Long Prairie to the northeast Twin Cities metro and Chippewa Falls, WI in the most likely region to cash on the snow amounts around 7 inches. These higher snow amounts will be driven by a heavy band of snow, where snowfall rates of near and above 1 inch per hour will occur in a 4-6 hour window (centered in the 5-10pm timeframe). With this continued southward drift in where the heaviest snow is expected, we did add Washington, St. Croix, Dunn, and Eau Claire counties into the Winter Storm Warning.

As for the Winter Storm Watch for Blizzard conditions, we decided to leave that as is. What is certain is that we'll see wind gusts of 40 to 50 mph (plus a few 50+) from west central through south central MN from roughly 1z through 8z (7pm through 2am). What is much less certain is how blowable that snow will be coming off a day where highs make a run at 40 with periods of rain and drizzle as well. Looking at the WSSI for blowing snow, it doesn't even show minor blowing snow impacts across southwest MN this evening. This region will likely see additional light snow, but that does not look to arrive late in the night Tuesday night, after the strongest winds have moved through. Although you can't rule out ground blizzard conditions, there are too many question marks in place to be putting out a headline (Blizzard Warning) that would have the effect of shutting down southwest MN tonight. Unfortunately, we're not really going to know how this snow will behave until we hit it with these winds. At the moment, there's too much of a chance that we just get some minor blowing, but not enough lofting of snow particles to create the visibility restrictions needed to support a blizzard.

After this system, it's back into the deep freeze through next weekend. The coldest day looks to be Saturday, when a high of zero looks like it will be difficult to attain everywhere in the MPX area. This will also see wind chill values down in the -25 to -35 range Friday night/Saturday morning and again Saturday night/Sunday morning, with the need for at least Extreme Cold Advisories both periods looking all but certain. Besides the cold, there will be more chances for light snow. Wednesday looks like your typical snow shower setup as we have well mixed boundary layers that have thermal profiles completely withing the dendritic growth zone. Thursday, a weak upper wave will move along the thermal gradient, laying down a quick band of light snow. Right now, this looks most likely to impact Iowa into southern MN. Friday, we should see another round of light snow move through with the passage of the arctic cold front. Saturday brings yet another wave embedded in the northwest flow that will work with the strong thermal gradient to create another swath of light snow, which at the moment is again favored for Iowa or southern MN.

Next week, a pattern shift still looks to be upon us as we see the eastern Canadian trough push into the north Atlantic, which allows upper ridging to move into the central CONUS. This looks to result in the active storm track shifting to the north, with milder Pacific airmasses moving in, with the cold easing as well. There's lots of snow to our south across Iowa, so it will be tough for us to warm significantly, but we'll take highs returning to the 20s and 30s for a little bit of a reprieve from the deep winter cold.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1149 AM CST Tue Dec 9 2025

Very complex forecast this afternoon & evening, mainly relating to where the rain/snow/ice transition line will setup this afternoon & how the track of the low pressure center will impact winds speeds this evening.

Generally, precipitation will spread from western Minnesota into eastern Minnesota & western Wisconsin through the afternoon. Maybe a 30 minutes to an hour of freezing drizzle or a wintry mix is possible as the precipitation begins, but that will quickly change over to snow. The snow will be heaviest across central Minnesota, where a few hours of visibility below 1 SM & rates around 1"/hr are likely. Across southern Minnesota (RWF/MKT), the snow will likely change back over to rain, then potentially end completely as a dry slot moves over the region.

The greatest uncertainty lies between these two areas (MSP/EAU), which will light right along the transition zone from snow to rain along with the edge of the dry slot. A few hours of moderate to heavy snow looks likely this afternoon into early evening, but precipitation then likely transitions to a light rain/snow mix, or even ends completely this evening. Eventually, light snow returns late tonight along with gusty northwest winds as the warp-around region of the system moves through the area. This snow ends during the early morning hours, with another round of lights snow looking likely from mid-morning into early afternoon.

Winds are very complex with this system, owing to uncertainty with the track of the surface low over the area. This afternoon, winds will remain southeasterly to southerly with speeds between 10-20 kts. As the surface low tracks over central Minnesota & western Wisconsin this evening, winds will likely become light & variable for a few hours (STC/MSP/RNH/EAU). Tonight, gusty northwest winds develop as the system exits the area, with gusts of 40-50 kts across southwest Minnesota (RWF/MKT) & generally 25-30 kts elsewhere. A few hours of LLWS is also likely this evening before the gusty Northwest winds develop late tonight, with northwest shear around 50 kts at FL020. The winds will be strongest late tonight into a few hours after midnight, then gradually decrease closer to 20 kts into the morning.

KMSP...Very uncertain forecast regarding the details, as discussed above. Could see roughly half an hour of freezing drizzle at the onset of precipitation between 2-3 PM, but this only cause light glazing on untreated surfaces. Moderate to heavy snow should quickly develop by 3-4 PM, with visibility likely below 1 SM & snowfall rates around 0.5" to 3/4"/hr. It remains uncertain how long this moderate to heavy snow will last, as a sharp cutoff with the dry slot of this system will setup somewhere over the Twin Cities metro. Best forecast for now suggests that the snow will begin tapering off by 6-7PM, when precipitation will either transition to a light rain/snow mix or end completely for a few hours. A second round of light snow then returns late tonight, likely 10-11 PM, which will have lighter rates, but gustier winds resulting in visibilities down to around 1-2 SM.

Winds this evening are probably the most uncertain part of the forecast. Confidence is high in SE to S winds into this evening with gusts around 20 kts early this evening. It then looks increasingly likely that winds will become variable for several hours tonight as the low moves overhead with speeds generally below 10 kts. Northwest winds then develop late tonight with the second round of snow, with northwest winds gusting to 25-30 kts into tomorrow morning. During the time of the likely lull in winds at MSP, very gusty northwest winds will develop in the dry slot across southern Minnesota, & these winds could extend into the southern Twin Cities metro. While it seems unlikely at the moment that we will see these surface gusts at the terminal, a few hours of LLWS is likely with W to SW shear of 50-55 kts in the lowest 2000-3000 ft.

/OUTLOOK FOR KMSP/ THU...MVFR. Chc -SN. Wind NW 5-10 kts. FRI...MVFR/SN early. VFR late. Wind NW 10-15G20 kts. SAT...VFR. Wind NW 10G20kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Winter Weather Advisory until 6 AM CST Wednesday for Douglas- Kandiyohi-McLeod-Meeker-Pope-Stearns-Stevens-Swift-Wright. Winter Storm Warning until 6 AM CST Wednesday for Anoka-Benton- Chisago-Isanti-Kanabec-Mille Lacs-Morrison-Sherburne-Todd- Washington. Winter Storm Watch from 9 PM CST this evening through Wednesday morning for Blue Earth-Brown-Chippewa-Faribault- Freeborn-Lac Qui Parle-Le Sueur-Martin-Nicollet-Redwood- Renville-Sibley-Waseca-Watonwan-Yellow Medicine. Winter Weather Advisory from 3 PM this afternoon to 6 AM CST Wednesday for Carver-Dakota-Goodhue-Hennepin-Ramsey-Rice- Scott-Steele. WI...Winter Storm Warning from 3 PM this afternoon to 9 AM CST Wednesday for Barron-Chippewa-Dunn-Eau Claire-Polk-Rusk- St. Croix. Winter Weather Advisory from 3 PM this afternoon to 9 AM CST Wednesday for Pepin-Pierce.