437
FXUS63 KARX 132336
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
536 PM CST Sat Dec 13 2025

.KEY MESSAGES...

- Apparent temperatures warming into the single digits below
  zero this afternoon will be short lived as apparent
  temperatures drop from -20 to -35 overnight into Sunday
  morning. Therefore, the ongoing Cold Weather Advisory for
  northern half of the forecast area will cover entire forecast area
  overnight into Sunday morning. More normal temperatures
  return for Tuesday with daytime highs in the 30s.

- Subsequent widespread preciptiation chances Wednesday night of
  a wintry mix with no precipitation type being ruled out across
  the forecast area.

&&

.DISCUSSION...
Issued at 1230 PM CST Sat Dec 13 2025

Cold will be the main forecast concern through the weekend as
freezing temperatures progressed as far south as the Red River
Valley along the TX/OK border and the Chattooga/Tugaloo River
Valleys along the SC/GA border this morning. The anomalous cold
seen locally in single digit above and below zero surface
temperatures. Off surface observations from ACARs, 12Z RAOBs,
and POES/GOES paint the collocated low level minima, near
record anomalous -20C isotherm at 925mb, from the Northern
Plains through Wisconsin into the northern Great Lakes. Expect
this main vein of Arctic air to continue south of the forecast
area through tonight as the wrapped upper level low over
southern Ontario on GOES water vapor imagery perpetuates
upstream troughing.

A synoptic upper level ridge over the Pacific West Coast on GOES WV
imagery returns /more/ normal, albeit a few degrees cool still
yet, temperatures on Monday as low level warm air advection
ramps up Sunday night into early Monday morning. While
temperatures will be increasing, a tightening low level
isoheight gradient will also increase wind speeds, persisting
below zero wind chills through Monday morning.

Similar to previous forecasts, confidence in coldest apparent
temperatures from 20 to 35 below zero locally tonight due to
proximity of anomalous Arctic airmass. Exit of the coldest
airmass through Sunday concurrent with passage of the low level
ridge axis keeping wind speeds low keeps confidence for ending
ongoing Cold Weather Advisory high. Confidence for above zero
surface temperatures in HREF increases through Sunday,
maximizing from 40-80% during peak diurnal heating. LREF Cluster
analysis has continued agreement for daytime high temperatures
in the 20s for most of the area on Monday.

Precipitation Chances Increase Wednesday Night:

Glancing synoptic lows wavering east/southeast near the
International border mean precipitation chances cannot be
completely ruled out in central Wisconsin counties Sunday night
or area wide Monday and Tuesday nights. Current confidence is
minimal, <15%. Regardless, the passing lows increase local
moisture ahead of subsequent synoptic cyclogenesis initiated
from remnants of early week re-intensification to the ongoing
Pacific Northwest Atmospheric River. Resultant widespread
precipitation potential impacts the Upper Mississippi River
Valley Wednesday night through Thursday. Current confidence is
low as a quasi- zonal mid/upper level pattern in clusters and
individual ensembles will undergo quick changes to cause
cyclogenesis across the central CONUS. Ensemble member spread in
low tracks is vast due to differences in exit behavior of early
week low tracks and varying solutions to the subsequent
synoptic upper level jet streak intensification.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 532 PM CST Sat Dec 13 2025

VFR conditions should largely prevail through the period. That
said, small axis of clouds mainly in the 1800-3500 foot range
are present from around AIT to AUW. These may slip southward
through our region and affect areas east of the Mississippi
over the next few hours. Have included a FEW mention at LSE to
cover this potential. Otherwise, winds will be out of the
northwest to begin the period and will turn counter-clockwise to
out of the south-southwest from 12z Sunday through the end of
the period.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Cold Weather Advisory until 10 AM CST Sunday for WIZ054-055-
     061.
     Cold Weather Advisory until 10 AM CST Sunday for WIZ017-029-
     032>034-041>044-053.
MN...Cold Weather Advisory until 10 AM CST Sunday for MNZ079-
     086>088-094>096.
IA...Cold Weather Advisory until 10 AM CST Sunday for IAZ008>011-
     018-019-029-030.

&&

$$

DISCUSSION...JAR
AVIATION...Ferguson