789
FXUS63 KARX 041925
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
125 PM CST Thu Dec 4 2025

.KEY MESSAGES...

- Periodic shots of light snow into next week. Generally minor
accumulations here and there (mostly from a few tenths to 2").
Saturday showing some potential for 3-4" across northeast IA. A
period to watch.

- Staying unseasonably cold. Sunday morning through Monday morning
looking like the coldest of the bunch with single digit above/below
zero and highs only in the teens.

&&

.DISCUSSION...
Issued at 125 PM CST Thu Dec 4 2025

OVERVIEW: progressive zonal/northwest-ish flow progged to hold
across the region through the weekend and into at least the early
part of next week. Several shortwave troughs look to bring light
snow to the upper mississippi river through the period. Temps will
fluctuate every few days...but mostly from very cold to just below
normal. No warmup of significance on the horizon.


SNOW CHANCES: periodic shots for light snow into the middle part of
next week as a procession of shortwave troughs spin across the
region.

First shortwave moves across the northern plains tonight, tracking
across the local forecast area Fri/Fri evening. Some low level warm
air advection precedes the shortwave with relatively weak QG
convergence through the layers. Enough saturation to produces light
snow, but not much for QPF. Weaker forcing also working against
higher snow totals. HREF currently suggest minor amounts, mostly
from a few tenths along/north of I-90 to upwards 1 1/2" north of I-
94.

In addition to the light snow, some of the models suggest the
potential for loss of ice in the cloud along the southern flank of
the snow band. Not clear cut, expansive or long lived. Low end
probabilities of freezing drizzle for now (10-20%) but something to
keep an eye on.

The next shortwave moves southeast from the PAC NW Friday, trekking
across the central plains Sat with the trough axis then moving over
eastern WI by 18z Sunday. Perkier feature with stronger QG
convergent response, favorable isentropic upglide on the 280:295K
surfaces, and potentially some Fgen and upper level jet support. The
bulk of the EPS and GEFS members hold a southerly track for the
system low (generally across MO, southern-central IL), how far
northward related pcpn extends still shows some uncertainty. While
the bulk of the EPS and GEFS lay out "most" of the snow across IA, a
handful of members extend accumulating snows well north of I-90.
Think this is reasonable. Slight uptick in potential amounts this go
around compared to previous days with 50% probabilities for 2"+
across parts of SE MN and NE IA...with 10-30% for 4"+ across NE IA.
A winter weather adv may be needed for parts of the area Sat if
these trends persist.

A few more perturbations look to sashay west to east across the
northern plains - upper mississippi river valley moving into next
week. Some discrepancies on timing/location/strength, but general
consensus with continuing those periodic light snow chances - and
minor accumulations. Will hold with the model blend for snow
chances.


TEMPERATURES: some "ups and downs" in the temperatures into next
week as shortwave troughs and weak ridging/zonal flow a loft take
turns influencing the region. Mostly, temps will hold at/below the
early December normals. CPC long range outlooks suggest it will stay
below normal through at least the mid part of December, if not the
entire month. Chilly start to the winter season for sure.

Sunday into Monday morning looking particularity cold with the
passage of a shortwave/cold front combo Saturday. Reinforcing shot
of cold air flows in post the system. Single digits below/above zero
for Sun/Mon mornings. Generally light winds will help cold air
drainage, but variable cloud cover uncertainties could mitigate more
extreme cooling. Sunday might be the coldest day of the next 7. 75%
of the GEFS and EPS members keep highs in the single digits to lower
teens...with southwest WI having the best shot to climb into the
upper teens. Wind chills will make it feel 5 to 10 degrees colder
through this period. Unless winds pick up, don`t see a need for cold
related headlines.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1115 AM CST Thu Dec 4 2025

Another arctic cold front will move southeast through the area on
Friday afternoon. As it approaches, the ceilings will become
IFR/MVFR late tonight and continue into Friday.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.

&&

$$

DISCUSSION...Rieck
AVIATION.....Boyne