textproduct: Twin Cities

KEY MESSAGES

- Rain this evening transitions to a wintry mix of sleet & snow late tonight south of Interstate 94.

- A narrow band of heavier snowfall rates will likely lead to slushy accumulations of 1-3" across south-central & southeast Minnesota by Tuesday morning.

DISCUSSION

Issued at 208 AM CST Mon Nov 17 2025

Wintry weather continues to look likely tonight as a shortwave passes south of the area through the central plains & mid- Mississippi valley tonight through Tuesday afternoon. The surface low from this shortwave will remain well off to our south, but a broad precipitation shield to its north is expected to spread into southwest & south-central Minnesota this evening. Dry antecedent dew points in the teens could delay the onset of precipitation for a few hours until later tonight, & will also likely result in a sharp cutoff wherever dry easterly to northeasterly flow persists ahead of the wave. For now model consensus brings this edge of the precipitation shield generally up to the southern Twin Cities metro & I-94 corridor through Wisconsin, & the highest probabilities for precipitation amounts of 0.25-0.5" across southern Minnesota. High resolution guidance continues to depict a narrow region of deformational forcing developing tonight within the precipitation shield over south-central & southeast Minnesota when the shortwave will be at its strongest. Heavier precipitation amounts of 0.5-0.75" are likely within this band, as well as where the chances are highest for a few inches of accumulating slushy snow overnight.

The wintry precipitation forecast with this system remains complicated, owing to surface temperatures & temperatures in the lowest few 1000s of feet of the atmosphere hovering right around freezing. In addition, higher dewpoints right around 32 degrees will also be advecting into southern Minnesota as the precipitation begins, meaning the effect of dynamic wet bulb cooling within the band of strongest forcing will not be as pronounced. High-resolution model guidance has pretty good agreement with the rain changing over to snow or a wintry mix of snow & sleet by midnight, although there are a few solutions such as the HRRR that begin the transition to wintry precip earlier in the evening. This timing in the changeover to wintry precipitation will play a large role on potential snow accumulations, as the models that depict an earlier transition show the potential for several inches of snow accumulation given the longer duration snow would have to accumulate. Further complicating the forecast is the likelihood for sleet to mix in with the snow for the first few hours during the changeover to rain to snow. "Snow"-liquid ratios for sleet are typically around 2-3:1, compared with the expected slushy snow ratios of 7-8:1 with this event, so that too will likely knock down potential snowfall amounts compared to some of the heavier snow solutions that depict a clean transition from rain to snow. Once the wintry mix transitions fully over to snow, we will see the heaviest snowfall rates near 0.5"/hr during the overnight & early morning hours, with the snow tapering off & ending by mid to late morning across southeast Minnesota.

While there is still some spread in high-resolution models regarding the transition from rain to snow & thus forecast snowfall amounts, the 25th-75th percentile spread on the HREF & REFS high-resolution ensembles along with the larger-scale GEFS/EPS/& EPS AI ensembles all suggest a swath of 1-3" of slushy snow is likely between Interstate 90 in the south and the southern Twin Cities metro in the north. The high-end 90th percentiles (earlier/cleaner transition to snow) from these ensembles do suggest a chance for amounts up to 4-6" within the heaviest band of snow, but even then the forecast model snow depth on these high-end model solutions suggests there would probably only be 2-4" of snow on the ground at any given time due to compaction & melting from the warm ground & near-surface temperatures. Since temperatures will be hovering right near freezing through the event, & quickly rise above freezing through the morning as the snow wanes, travel impacts from the snow will likely be limited to when the snow is falling. However since is the first appreciable snowfall of the year for many, plan on a slow & slippery commute Tuesday morning from the Twin Cities metro & south. High temperatures are forecast to reach the upper 30s & low 40s by the afternoon so any snow is unlikely to last long on roads & pavement by the time the Tuesday evening commute comes along.

Beyond Tuesday, temperatures look to be on the warm-end of normal into the weekend, with chances for light precipitation coming Thursday as a weak shortwave skirts across northern Minnesota. The bulk of the precipitation from this system should remain over northern Minnesota. Another, much stronger, system looks likely over the mid-Mississippi valley late Thursday through Friday, but ensemble guidance continues to keep even the northern fringes of the precipitation shield with this system to our south over Iowa.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1125 AM CST Mon Nov 17 2025

Very few changes made to ongoing TAFs. Continued VFR at initialization and through this afternoon with stratus decks around 5-6 kft. Still looking for precipitation to develop tonight through tomorrow morning, starting out as rain in southwestern MN. The transition to -SN looks to occur during the overnight hours, with precipitation by sunrise to be all -SN and continuing into late morning before ending. MVFR conditions likely with the onset of the precipitation then dropping into IFR levels as the precip mixes with and changes over to -SN. Models continue to advertise this event as a moisture-laden snow, with liquid totals potentially between 0.60"-0.80". Compaction and settling will likely put this snowfall in the 1-3" range, heaviest in far southern MN but still enough of a northward nudge into the TC metro to bring impacts to MSP. Winds to slowly back from E today to NE tonight into tomorrow with speeds generally around 10kts.

KMSP...MSP is right on the edge between lighter precip and heavier precip, so a one degree difference or a slight nudge in the precip shield could make the difference between a trace rain/snow event and one with slushy plowable snow accumulation during the morning push. Latest model trends are leaning more to the latter scenario, as even with ground temps not dropping below zero, there are some indications that heavier bursts of snow (including around 1 in/hr rates in that 11z-15z timeframe) are reasonable to occur. Thus, have "upped" the potential for IFR-worthy visibilities from a PROB30 to a TEMPO. Visibility impacts will be mainly limited to snowflake size and intensity as wind speeds will remain under 10kts throughout from the E.

/OUTLOOK FOR KMSP/ WED...MVFR, IFR CIGS possible. Wind S 5-10 kts. THU...MVFR. -SHRA possible. Wind SW bcmg NW 5-10 kts. FRI...VFR. Wind N 5-10 kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None.