629
FXUS63 KARX 282328
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
528 PM CST Fri Nov 28 2025

.KEY MESSAGES...

- A winter storm moves through the region tonight through
  Saturday night providing a prolonged period of accumulating
  snow. Probabilities for 6+" of snow are 70-95%, highest along
  and south of I-90 with areas in northeast Iowa and far
  southwest Wisconsin potentially (20-80%, increasing north to
  south) reaching a foot. Blowing snow may occur west of the
  Mississippi Saturday evening.

- Cold temperatures remain through next week with highs in the
  upper teens to mid 20s. Overnight lows fall into the single
  digits above and below zero Sunday night into Monday morning
  and potentially again Wednesday night into Thursday morning.

- Additional snow may (20-35%) occur Monday into Monday night,
  Tuesday night into Wednesday, and Thursday night.

&&

.DISCUSSION...
Issued at 150 PM CST Fri Nov 28 2025

Winter storm on tap

18z WV satellite shows a broad upper trough over ID and an upper low
over Quebec. Westerly upper jet over UT/CO is being sampled by GOES
with 50-60 knot winds over the Rocky Mountain Front Range from NE NM
northward to WY. At the surface, lee troughing is ongoing in the
western High Plains. Farther east, broad surface high is present in
the wake of the eastern upper low. Temperatures in the forecast area
are in the mid 20s with surface dewpoint depressions around 10-15
degrees F.

Today into tonight, as the western upper trough advances
southeastward, lee surface low will develop in SE CO and hook toward
NE MO. With the surface high shifting to the eastern CONUS,
southerly low level moist advection will occur across the central
CONUS, leading to widespread precipitation. In our neck of the
woods, despite the southerly fetch in the low levels, temperatures
will remain below 0C through the column with saturation extending
through the DGZ. Therefore, snow remains the only expected precip
type in our CWA. Precip generation will focus on two regimes - the
initial warm advection tonight into Saturday morning and then as
lift occurs ahead of the main body of the upper wave while moisture
continues to wrap around the north side of the surface low. This
should result in a prolonged period with moderate snow with highest
amounts in northeast Iowa and far southwest Wisconsin where lift and
snow residence time will likely be maximized. Of particular interest
is the presence and location of any enhancement due to
frontogenesis. Trend noted in previous update toward the presence of
an axis of modest 900-700mb frontogenesis continues in short term
guidance this morning and in the 28.12z global suite. 28.15z RAP
suggests this will be located from roughly Charles City IA to
Menominee WI Saturday evening, potentially enhancing snow totals in
this area. Thus, while totals will tend to follow a consistent north
to south gradient, could see some enhancement west of the
Mississippi Valley and the highest totals within our CWA in
Floyd/Chickasaw Counties.

As for what those amounts are, with around 18-24 hours of snow rates
of between 0.5-1" per hour and surface compaction ongoing through
the event, am very confident (75-95%) areas along and south of
Interstate 90 will receive at least 6". Slight northern jog in track
of the low has continued with latest guidance, so have increased
amounts around 1" across the board and added Clark County to the
Winter Storm Warning. As for who gets closer to the 12" mark, our
southern counties (Floyd-Chickasaw-Fayette-Clayton IA and Grant WI)
have the best shot, 50-80% per 28.12z SPC HREF output.

Finally, with the closer track of the surface low, 35 mph wind gusts
appear very likely (80-100%) Saturday evening, particularly west of
the Mississippi. Should any location experience moderate snow as
these gusts occur, very low visibility (1/2 mile or less) would
result. Will need to closely monitor end timing of moderate snow
rates as this combination would lead to a corridor of highly
dangerous driving conditions within the broader issues across the
region.

Cold next week

Extended period of mainly northwesterly flow aloft is expected in
the wake of Saturday`s upper wave. This should lead to an extended
period with below normal temperatures. Coldest mornings should be
Monday and Thursday mornings (28.12z NBM 40-90% and 30-80% chance
for subzero lows, respectively). Breezy conditions appear unlikely,
so wind chills should remain above advisory level (-25).

Additional shots at snow

Passing upper troughs within the northwesterly flow aloft may lead
to additional light snow showers or flurries Monday, Wednesday, and
Thursday night. Monday and Thursday night appear to have the
potential to generate additional hazardous travel conditions should
everything come together, however Monday`s snow looks likely (80%)
to remain to our south and guidance spread in key timing and
location details is large for Thursday night. Too early to make
pronouncements but something to keep an eye on once Saturday`s snow
departs.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 528 PM CST Fri Nov 28 2025

VFR conditions to persist until snow arrives this evening into
the early overnight. While it is snowing, lowered flight
categories (MVFR to IFR) due to low CIGS and reduced
visibilities will occur. Areas may see LIFR conditions due to
CIGS getting below 500ft or if snow rates are higher,
visibilities may drop below 1/2SM. The best time for LIFR
conditions looks to be Saturday afternoon and evening. Snow
continues through the day Saturday, ending Sunday morning. Light
and variable winds this evening shift to easterly winds for
much of the TAF period. Winds begin to shift more northeasterly
Saturday evening.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Storm Warning from midnight tonight to 6 AM CST Sunday
     for WIZ053>055-061.
     Winter Weather Advisory from 6 AM Saturday to 6 AM CST Sunday
     for WIZ017.
     Winter Storm Warning from 3 AM Saturday to 6 AM CST Sunday for
     WIZ029-032>034-041>044.
MN...Winter Storm Warning from midnight tonight to 6 AM CST Sunday
     for MNZ079-086>088-094>096.
IA...Winter Storm Warning from midnight tonight to 6 AM CST Sunday
     for IAZ008>011-018-019-029-030.

&&

$$

DISCUSSION...Ferguson
AVIATION...Cecava