textproduct: Twin Cities

KEY MESSAGES

- Potential is increasing for first winter storm of the season Tuesday afternoon into early Wednesday morning.

- Corridor of heaviest snow continues to shift south with several inches possible across portions of central Minnesota, where a Winter Storm Watch has been issued.

- Strong northwest winds gusting 40 to 45 mph will result in blowing snow and difficult travel conditions.

- Much colder with additional snow chances later this week.

DISCUSSION

Issued at 230 AM CST Mon Nov 24 2025

Skies remain clear at the moment across much of the Upper Midwest with mild temperatures in the mid 30s to lower 40s. An upper level low over western Kansas will continue east to Missouri by this evening. Moisture advecting north ahead of it has reached southern Iowa early this morning with low clouds and areas of fog developing. Southerly flow will bring this moisture to MN later this morning. A few rain showers are possible this afternoon and tonight across southern/eastern MN and WI, but amounts will be rather light.

Meanwhile, a shortwave trough over Washington state will progress east to the northern Rockies this evening and the Dakotas late tonight. It will dig appreciably on Tuesday as it reaches southern MN. Rain will become more widespread Tuesday morning, then as the upper low reaches maturity Tuesday afternoon, a well-defined deformation band will be in place on the northern and western quadrants of the low. Colder air will advect in quickly after the low passes and rain will turn to snow, which may be heavy at times. The TROWAL will wrap around the low to the south, spreading a period of light snow as far south as southern MN Tuesday evening. Snow totals are increasing as the latitudinal placement of the deformation band continues to shift south. Several inches are possible. It shouldn't take long to begin sticking with decent rates and temperatures dropping into the 20s, but strong winds may stunt snow ratios some and lead to compaction. Positive snow depth change maps vs Kuchera or 10:1 ratio maps highlight this potential well.

Steep low level lapse rates with strong CAA and a northerly low level jet of nearly 50 kts on the backside of the low will increase surface winds markedly. In fact, forecast soundings show 40-45 kts toward the top of the boundary layer. Peak surface gusts of 35-40 kts are probable. Combined with the falling moderate to occasionally heavy snow rates, travel conditions will become difficult. A Winter Storm Watch was issued for parts of central MN, mostly north of a line from Morris to Mora. This is where the highest snow totals are expected and where travel will be most difficult.

Overall, the trend of the swath of heaviest snow continues to shift south with the numerical models due to a more aggressively digging trough and deeper upper low. Ensemble means are also beginning to show better definition with smaller scale features, signaling the spread is decreasing. AI output has shown only slight signs of further strengthening of the trough, otherwise there has been little change in the last several runs. The AI output has been farther south compared to the numerical output for a while, so it appears the latter is beginning to catch up. With all of that said, NBM is lagging behind the trend a bit so expecting snow totals to again increase today, barring any significant reversal of recent trends.

The winds will ease Wednesday as high pressure build in. Quiet weather is expected into Friday, but another system over the northern Rockies will track to the central Plains Friday night. A band of light snow may stretch from the Dakotas to central and southern MN by early Saturday. Beyond Saturday, there remains considerable spread with any subsequent system and confidence is very low.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 509 AM CST Mon Nov 24 2025

This period will include gradually falling CIGS amidst chances for -SHRA and BR, with CIGS/VIS falling to MVFR/IFR at times. The overnight stratus approaching from the south has been significantly slower than expected, leading to a general increase in early cloud levels and VFR for all sites. This has also delayed the onset of MVFR/IFR a bit today, with winds light and variable throughout. It will end up being a day where amendments may be needed due to the poorly handled progression of the morning cloud cover in the short-range guidance, with a reliance on some of the shorter term observations to adjust the timing of the CIGS/VIS and -SHRA.

KMSP...In general, went with a slower pace for the onset of MVFR/IFR compared to prior TAF due to the slow progression of the cloud cover in Iowa right now. Once we begin to see CIGS and eventual MVFR/IFR, we are not going to improve until we begin to clear out by late Wed to early Thu. The CAM guidance has not handled the morning cloud cover well at all, thus we may need some additional amendments throughout the day as we rely more on observations from where the cloud cover is progressing from than the model guidance.

/OUTLOOK FOR KMSP/ WED...MVFR/IFR/-SHSN early. Wind NW 15-20G30kts. THU...VFR. Wind NW 10kts. FRI...VFR. Wind NW to SE 5kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Winter Storm Watch from Tuesday morning through late Tuesday night for Douglas-Pope-Stevens-Todd. Winter Storm Watch from Tuesday afternoon through Wednesday morning for Benton-Kanabec-Mille Lacs-Morrison-Stearns. WI...None.