906
FXUS63 KMPX 180001
AFDMPX

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

.KEY MESSAGES...

- Rain and snow develops this evening across southern Minnesota
  and overnight across west central Wisconsin.

- Heavy snow rates are possible, but temperatures aloft remain
  critically close for either a rain/snow mix or mostly snow.

- Sharp cutoff to the precipitation on the northern edge is
  leading to lower confidence for the Twin Cities metro.

- Higher confidence for snow accumulation exists along a line
  from Redwood Falls to the southern Twin Cities Metro and
  towards Eau Claire. If precip type becomes mostly snow, 3 or
  more inches are possible. A Winter Weather Advisory has been
  issued for the risk of heavy rates and higher amounts. There
  is a conditional risk for hazardous travel conditions during
  the Tuesday morning commute.

&&

.DISCUSSION...
Issued at 248 PM CST Mon Nov 17 2025

A very complex forecast is unfolding for tonight and Tuesday
morning. A compact upper low over the central Plains will
continue east tonight and reach Iowa Tuesday morning. A narrow
band of rain is developing across southern SD, with
thunderstorms also ongoing in southeastern SD. This band will
lift north for the rest of the day into the evening and become
better developed by the time it reaches southern MN. Anomalously
high pwats of nearly 0.9 inches are advecting north and will
wrap to the northern side of the system tonight. Strong
frontogenetic forcing and conditional symmetric instability will
be present in the DGZ later this evening. The band will mature
during this time and should lead to heavy precipitation. It will
likely remain quite narrow and models are still showing small
run to run differences in its latitudinal extent. These small
differences may not normally lead to significant outcomes, but
given that the band will be narrow and there will be a very
sharp cutoff of the precipitation on its northern flank, this is
leading to much lower than normal confidence along a line from
Canby, to the Twin Cities metro, to the Eau Claire area. Little
is expected north, and about 0.75 inches of liquid equivalent
precipitation is expected just about a county to the south.

Forecast soundings from just about every model continue to
exhibit an isothermal profile at 0C from the surface to ~8 kft.
This means that a 1 degree variation one way or the other will
result in all rain or all snow. Given the QPF, expected precip
intensity, and most precip falling overnight, an all snow
scenario would result in several inches. Continued to highlight
rain this evening turning to a mix of rain and snow overnight.
Conceptual models favor more snow, but the very high pwats may
limit the atmosphere`s ability to cool much more than freezing.
Therefore, equal parts of the QPF forecast have been distributed
to the rain bin and the snow bin, yielding roughly 2 or 3
inches of snow in the advisory area. In addition, the favorable
dynamics will be highly efficient in producing dendrites, and as
those dendrites descend through a deep isothermal layer around
freezing they will continue riming and form aggregates. These
aggregates could be large and effective at quick accumulation.

Since this is the first snow of the season and will be
occurring during the morning commute, we are a bit more liberal
with issuing a Winter Weather Advisory. The northern half of the
metro may not see much or any, but the southern half may. The
core metro will need to be considered in future updates, but
given such a low confidence forecast with the cutoff very close,
left out Hennepin, Ramsey, and Washington counties for now. The
rain and snow will wrap up mid morning. Clearing will take
place across central MN, but considerable cloud cover will
remain to the south.

For the rest of the period, a mild airmass and quiet weather
will prevail across much of the country through early next week.
PoPs have decreased with the system Wednesday night into
Thursday with precip likely remaining north.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 553 PM CST Mon Nov 17 2025

Very few changes made from the 17/18z TAF set. Continued VFR at
initialization into this evening stratus decks around 5-6 kft.
Still looking for precipitation to develop tonight through
tomorrow morning, briefly starting out as rain in southwestern
MN. The transition to -SN looks to occur shortly after onset
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 continue the slight
northward push of the snow swath, 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. 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...Winter Weather Advisory from midnight tonight to 9 AM CST
     Tuesday for Brown-Carver-Dakota-Le Sueur-McLeod-Nicollet-
     Redwood-Renville-Rice-Scott-Sibley-Yellow Medicine.
     Winter Weather Advisory from 1 AM to 11 AM CST Tuesday for
     Goodhue.
WI...Winter Weather Advisory from 1 AM to 11 AM CST Tuesday for Eau
     Claire-Pepin-Pierce.

&&

$$

DISCUSSION...Borghoff
AVIATION...JPC