544
FXUS63 KARX 271728
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1128 AM CST Thu Nov 27 2025

.KEY MESSAGES...

- A chilly Thanksgiving is in store with highs topping out in
  the upper 20s and wind chills in the teens. Isolated to
  scattered snow showers are possible this afternoon (20-30%)
  mainly along and east of the Mississippi River, but impacts
  will be minimal.

- A winter system moves through the region Friday night through
  Saturday night providing a prolonged period of accumulating
  snow. Probabilities for 6+" of snow are 70-90%, highest along
  and south of I-90. A Winter Storm Watch has been issued, so
  continue to monitor the forecast!

- 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 by the beginning of next week.

&&

.DISCUSSION...
Issued at 421 AM CST Thu Nov 27 2025

Thanksgiving Day

With the bulk of yesterday`s winter system moved off to eastern
Canada, quieter conditions are expected for Turkey Day.
However, chilly conditions are in store as high temperatures
are expected to top out in the upper 20s. Breezy northwest winds
are also expected through the day with gusts of 20-30mph
associated with an increased low level synoptic wind field
remaining situated over the region which will result in wind
chills in the teens. Make sure you`re prepared if spending time
outdoors for the holiday!

In addition the cold temperatures and breezy winds, there is
the potential for some isolated to scattered snow showers late
this morning through the afternoon (10-30%) primarily along and
east of the Mississippi River as low level cold air advection
results in 0-2km lapse rates of 6.5-7.5 C/km and upwards of 40
J/kg of 0-3km CAPE reaching into a saturated DGZ. Impacts should
be minimal, but could see some light accumulations in more
vigorous showers.

Winter System Potential Friday night through Saturday

A 500hPa shortwave trough moves into the Pacific Northwest this
morning, quickly translating southeastward and invigorating
cyclogenesis over the Great Plains on Friday. In response, a low
pressure system develops, moving northeastward through the
Midwest Friday night through Saturday, shifting eastward on
Sunday.

Warm air advects northward into the region as this low develops
along with a band of 850-700hpa frontogenesis. These features
should lead to snow developing across the region by Friday night
as thermal profiles are depicted to be below freezing
throughout the column. Snowfall rates are expected to be
highest with this frontogenesis band, but it quickly dissipates
Saturday morning. Synoptic forcing in the form of warm air
advection and isentropic ascent on the 275-285k surface then
becomes the primary supporting features for additional snowfall
through the day Saturday with light to moderate snowfall rates
through much of the event.

A southward shift in the track of this low is noted over the
past 24 hours which has subsequently shifted the axis of highest
snowfall probabilities further south. The 27.01z NBM continues
to indicate high probabilities for snowfall amounts greater
than 6 inches (70-90%), but now highlights northeast Iowa into
southwest Wisconsin as the favored location of this axis of
higher potential. This southern trend is in agreement with the
27.00z LREF as nearly 75% of the members are clustered on this
or a very similar solution. Overall, amounts are currently
expected to be highest along and south of I-90 and as such a
Winter Storm Watch has been issued for these areas.

All this said, the bottom line is a prolonged period of
accumulating snowfall is expected Friday night through Saturday
night with 70-90% probabilities of 6+" snowfall totals. This
snowfall could impact post-Thanksgiving travel, especially on
less traveled roads. Continue to monitor the forecast as the
track of the storm and subsequent impacts could continue to
shift as we get closer to Friday night.

Cold Temperatures

In the wake of this weekend`s system, northwest flow ushers
another cold airmass into the region, reinforcing the already
cold temperatures in place. High temperatures will only climb
into the teens to mid 20s through early next week with overnight
lows falling into the single digits both above and below zero.
There is some uncertainty in the ultimate temperatures realized
as the 10th-90th temperature spread in the 27.01z NBM sits
around 5-10F through Tuesday. This uncertainty largely lies with
how the expected snowpack from this weekend`s snowfall
develops, although the 90th percentile for high temperatures
sits well below freezing.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1128 AM CST Thu Nov 27 2025

Scattered to overcast cigs at low-VFR to MVFR heights will be the
primary aviation concern throughout the afternoon and into the
evening. In addition, steeper low-level lapse rates and some weak
instability will allow for some snow showers to develop near and
east of the Mississippi River that could result in isolated category
vsby reductions. However, confidence was too low (10-20% chance in
the recent HREF) in the to include at KLSE at this time with
higher probabilities further east. RAP/HRRR soundings indicate
some drier air tries to sneak in overnight which may raise cigs
somewhat before additional scattered to perhaps broken MVFR cigs
return for the early part of the day on Friday. Northwest winds
will slowly diminish throughout the TAF period beginning at
around 12-18 kts at 18z and falling below 10 kts overnight.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Storm Watch from late Friday night through late
     Saturday night for WIZ041-042-053>055-061.
MN...Winter Storm Watch from late Friday night through late
     Saturday night for MNZ086>088-094>096.
IA...Winter Storm Watch from late Friday night through late
     Saturday night for IAZ008>011-018-019-029-030.

&&

$$

DISCUSSION...Falkinham
AVIATION...Naylor