473
FXUS63 KMPX 170905
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
305 AM CST Mon Nov 17 2025

.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 /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1046 PM CST Sun Nov 16 2025

Stubborn mid level stratus has been very slow to dissipate this
evening and looks to stick around based on model soundings such
that the beginning of the TAF has been revised to include mid
level VFR CIGS from MSP and westward, with only RNH/EAU
remaining relatively clear with only some high clouds moving
through. CIGS will increase in coverage and lower towards midday
as the forcing from what will eventually be chances for rain
begins to move in from the south/southwest. -RA chances begin
generally around 22-23z for RWF/MKT and an hour or two later for
MSP/STC/AXN, with CAMs showing the most likely beginning to
transition to -RASN being around 02-03z. The way the forecast is
expected to play out is to have a relatively narrow band of SN
which will reduce visibilities and lead to accumulations, right
now most likely for RWF/MKT with the northern edge potentially
reaching MSP from the time window of roughly 03-12z with
lingering precipitation quickly diminishing after 12z as forcing
departs.

Winds will begin light and variable, shifting towards 100-130
and increasing to around 10kts as the -RA arrives, with
occasional gusts to the low 20kts possible.

KMSP...Still an uncertain forecast based on where the most
likely zone for a band of snow sets up, which right now still
favors the Minnesota River Valley with MSP on the northern edge
where we could either end up dry, or end up with an inch or so
of slushy accumulation. The time window for any potential snow
would be 03-09z with -RA from 22-23z to 03z ahead of a
transition to snow. Surface temperatures will be near freezing
so we are not expecting a flash freeze type of scenario that
would lead to the rain freezing on pavement or aircraft, however
if the heavy snow band ends up farther north we could see
temperatures drop enough to cause some minor icing issues. Right
now the likelihood for that would be less than 15% given the
overall suite of guidance showing a higher likelihood towards
MKT, however it still remains enough of a percentage to keep it
in mind moving forward. Legitimate freezing rain is not
expected, nor is freezing drizzle expected to cause any icing,
it would purely be from high enough snow rates to cool the
ground enough to freeze up any lingering moisture, so if we do
not end up seeing snow we can expect to have zero icing issues.

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

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...ETA
AVIATION...TDH