textproduct: Twin Cities

KEY MESSAGES

- Late November winter storm underway across the Upper Midwest. Several inches of heavy snow, strong northwesterly winds, and rapidly falling temperatures will create significant travel impacts this afternoon through Wednesday morning.

- Snow will continue to blow and drift Wednesday. Much colder air settles into the region for the rest of the week.

- Additional snow chances arrives late Friday into Saturday. A few inches of accumulation appear possible south of I-94.

DISCUSSION

Issued at 115 PM CST Tue Nov 25 2025

BOTTOM LINE UP FRONT...Rain will transition to snow from west to east through the remainder of the afternoon and evening. Winds will intensify as the transition occurs, creating periods of white-out conditions and slick travel. Please avoid any non-essential travel.

WINTER STORM WARNING THROUGH WEDNESDAY MORNING... The well advertised late November storm system is rapidly circulating over the eastern Dakotas early this afternoon. The appearance of the dynamic processes the compact storm is currently undergoing is stunning on GOES-IR satellite! The system's closed upper-low is progged to advance east across central MN this afternoon and continue eastward towards central WI by mid-morning tomorrow, eventually taking on a bit of negative tilt aloft. In response, ~1008mb surface low pressure will undergo cyclogenesis over eastern MN/western WI and deepen into a mature low-990s mb surface cyclone over the northern Great Lakes by midday tomorrow. Given this evolution, an intense deformation band of snowfall supported by a TROWAL and mid-level frontogenesis will yield heavy snowfall rates and several inches of snowfall accumulation. As a result of a southerly jog in the storm system over the past 24-36 hours, locations along and north of I-94 across central MN remain the focus for the greatest snowfall amounts (6-8" from roughly Alexandria to St. Cloud to Ladysmith). A more widespread wrap-around shield of snowfall will expand across southern MN, supporting a forecast of 4- 6" from Lac Qui Parle east towards the Twin Cities. Farther south, a couple inches of snow accumulation can be expected. There are two other players in this forecast -- Strong northwesterly winds, which will sustain between 20-30 mph and gust upwards of 40-45 mph (possible near 50 mph in isolated instances!) in tandem with falling snow and rapidly falling temperatures. It's the combination of heavy snow and strong winds that prompted the Winter Storm Warning across the majority of central/southern MN and portions of western WI north of I-94 through 9 AM Wednesday. Additionally, a Winter Weather Advisory continues across far southern MN (along I-90), Goodhue (MN), and Pierce, Pepin, Dunn, Chippewa, and Eau Claire (WI). Travel conditions will be significantly impacted as rain transitions to snow and continues to fall/blow through the night. Slick travel conditions will likely continue into the Wednesday morning commute.

APPROXIMATE RAIN TO SNOW TRANSITION TIMES:

**SLIGHTLY SLOWER THAN INITIAL AFD ISSUANCE AT 1 PM**

WEST CENTRAL MN (ALEXANDRIA) - Heavy snow is already reported early this afternoon.

CENTRAL MN (ST. CLOUD/WILLMAR/MORA) - 4-6 PM

TWIN CITIES - WEST METRO (7-9 PM), EAST METRO (8-10 PM)

SOUTHERN MN (MANKATO/FAIRMONT/ALBERT LEA) - (9-11 PM)

WEST CENTRAL WI (LADYSMITH/EAU CLAIRE) - (MIDNIGHT - 2AM)

TECHNICAL ASPECTS OF THE SNOW FORECAST...The heaviest snowfall rates will occur in the first 2-3 hours after the transition from rain to snow. Forecast soundings across central MN reveal a saturated DGZ that is roughly 3-5k feet deep. Strong omega forcing, conditional slantwise instability, and mid-level frontogenesis will support snowfall rates of 1"/hr, with a narrow corridor of 1"+/hr rates possible. Given the swift moving nature of this system, the residence time for the heaviest rates is of a shorter duration, however a longer period of 0.5"/hr snowfall rates will persist into the night. Snow character/SLR's will run on the wetter side during the initial transition (say, roughly 7-10:1), however the strong CAA and dynamic nature of this system will allow for a SLR's in the ~13- 15:1 range to be more of a commonplace through much of the event. Cameras across the eastern Dakotas reveal a large flake size, which certainly is understandable given the depth of DGZ -- However, the expected magnitude of the wind fields below the DGZ may be somewhat of a negative aspect to snowflake size tonight due to fracturing (This is why we're not running with higher SLR's despite the magnitude of CAA).

We have high confidence in the evolution of this winter storm over the next 18 or so hours. One potential "failure mode" for snow amounts is associated with the system's dry slot currently observed on water vapor imagery wrapping in from NE/IA. We do not think this feature is going to have much of an impact on the snowfall scenario across central MN/western WI. However, it is possible that the dry slot may cut snowfall totals across southern MN by about an inch or so. *While this is an area of uncertainty, it will not have much of an impact on the sensible conditions, as the strong winds will only need a few inches of falling snow to create a very challenging travel situation.*

Snow ends from west to east heading towards daybreak Wednesday. Crashing temperatures and breezy winds on the backside of the system will keep the potential for blowing snow around through at least mid- morning (this is why the headlines are in place through 9 AM). Morning wind chills will dip into the single digits and will only reach the mid-teens tomorrow afternoon. The storm system will have ushered in a much colder airmass that aims to stick around for the foreseeable future -- look for highs in the 20s and lows in the teens through the upcoming weekend.

REST OF THE WEEK/WEEKEND...High pressure will build over the north central CONUS heading into Thanksgiving Day. Anticipate a rather tranquil day of weather, with mostly sunny skies and highs in the 20s. However, the brief break in the active pattern will be short- lived, as an active upper-level pattern will send another storm system through the central CONUS heading into the upcoming weekend. Driving this storm system is a shortwave trough that aims to dig from the Pacific Northwest towards the central Plains. The wave will track along a remnant baroclinic zone that is forecast to setup across the central Plains following today's storm system/southward expansion of the cold Canadian air mass. While we're still a couple of days out (and the forecast is likely to fluctuate in some capacity), that 12z guidance paints a picture that is rather snowy across southern MN to open this weekend. Latest consensus depicts a mid-level frontogenic band of snow developing over the Dakotas/SW MN later Friday, followed by a more expansion shield of precipitation heading into early Saturday. Following surface cyclogenesis over the Plains early Saturday, the cyclone is progged to advance northeast through the Great Lakes. Depending on the track, the system's region of deformation snowfall may also pass over portions of the CWA. The setup supports the potential for several inches of accumulating snow over southern MN, with perhaps a longer duration light snow event towards I-94. Guidance reveals no shortage of moisture, as a prolonged fetch of southerly flow aims to advect PWATs nearly ~150 percent of normal by late Friday across southern MN. Latest NBM PoP's are very impressive at this distance, with 80-90 PoPs across south central MN Friday evening and 50-70 PoPs along the I-94 corridor. Still some pieces to put together with more specific timing, duration, and amount of snow...but the slower moving "slider" nature of this winter storm archetype may make for a longer duration light to moderate snow event that could result in travel challenges following the holiday.

A reinforcing shot of Polar air, characterized by 850 mb temp anomalies of roughly -15C, will send surface highs into the teens and lows into the single digits to close the weekend and open the upcoming work week. Of course, the localized effects of a fresh snowpack may send temperatures below blended guidance. It looks like a very cold start to December!

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 530 PM CST Tue Nov 25 2025

A complicated setup this evening across Minnesota and Wisconsin. We have AXN and STC already in the full force of the snow with LIFR or IFR conditions. Then we have RWF and MKT in the break between the rain and snow. Last we have MSP and the WI terminals in the rain. The transition to snow will continue to move from west to east with some, especially the south of I-94 sites seeing a break between the rain and snow with a brief dry slot. As the transition to snow occurs ceilings and visibility drop quickly to IFR or LIFR. Within a hour after the snow starts winds will pick up from the northwest and provide for a period of the worst conditions where snowfall and high winds overlap. This period will be roughly 4 to 6 hours in length. Once the snow starts to lighten up blowing snow will keep visibility reduced for a few more hours. Winds will keep blowing through tomorrow, but as the snow settles it will be less blowable. Overall a difficult period for aviation weather with an extended period requiring instrument rating and even a few possible hours of (non-core 30) airport closure.

KMSP...Coming to the end of the rain at TAF issuance time. Still some very light rain or drizzle, but little impact beyond the MVFR ceilings. Winds will be complicated as southwest winds moved in and will likely stick around until we see the shift to the northwest around the start of the snowfall. So the main impacts will all be tied to when the snow starts. Pushed back the start time a little back farther to 04Z with the worst conditions expected 05Z to 10Z. So thankfully the worst conditions should be during some of the quietest traffic hours. Biggest thing to keep an eye on will be how quickly the snow tapers off as the morning rush starts. Even if the worst is done before the rush the continued gusty northwest winds will be blowing snow around through much of the morning. Conditions should improve by afternoon.

/OUTLOOK FOR KMSP/ THU...Chc MVFR cigs. Wind NW 10-15G20-25kts. FRI...VFR. Chc MVFR/-SN late. Wind NW to NE 5-10kts. SAT...VFR. Chc MVFR/-SN early. Wind NE to NW 10-15kts.

MPX WATCHES/WARNINGS/ADVISORIES

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