634
FXUS63 KARX 210523
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1123 PM CST Thu Nov 20 2025

.KEY MESSAGES...

- Low stratus and patches of fog and drizzle continue through
  this afternoon.

- Gradual warm up for the weekend with highs generally in the
  upper 40s to mid 50s.

- Increased rain chances (50 to 75%) for Monday into Tuesday.
  Colder temperatures for the second half of next week.

&&

.DISCUSSION...
Issued at 1219 PM CST Thu Nov 20 2025

Today: Drizzle

Deep low level saturation continues today with low stratus as well
as some fog and drizzle at times. These conditions are expected to
continue until a weak cold front pushes through the region later
this afternoon into the early evening, helping to bring in drier air
and lifting the cloud deck. With the low clouds in place for much of
the day, have continued the trend of lowering high temperatures for
today. High temperatures for day are now mostly in the 40s across
the CWA.

Friday-Sunday: Dry and Gradual Warm Up

A split flow upper level pattern covers much of the northern Plains
and Upper Midwest into early next week. A trough sets up to our
north with a shortwave coming out of the souther Rockies. Guidance
continues to show this system from the Rockies staying to our south
with minimal rain chances (<15%) for our far southern counties.
There is low chance that a shortwave comes far enough south on
Saturday afternoon into Sunday that could bring some light rain
showers to areas north of I-94, however only the deterministic ECMWF
and 5% of EPS members show this solution occurring. The NAM does
indicate some shower potential as there is a weak cold front that
accompanies this wave. One thing inhibiting more guidance showing
showers, is that based on NAM and GFS soundings at this time, there
is quite a bit of dry air in the low levels. This wave may more than
likely just increase cloud cover briefly. Outside of these low
chances, a mostly dry weekend is in store. Temperatures for this
weekend are looking quite pleasant for late November with highs
generally in the upper 40s to low 50s. Sunday is expected to be the
warmest day with highs mostly in the low to mid 50s.

Monday-Thanksgiving: Increased Precipitation Chances Through
Midweek, Cooler Temperatures Mid to Late Week

The split level flow becomes interrupted on Monday evening as a low
pressure system comes up from the southern Rockies. Previous
forecasts had this system staying mainly south of the forecast area
with only the EPS showing most of its members (70 to 80%) with
measurable precipitation while the GEFS members hardly had any
members (around 30%) with precipitation. Since yesterday, Ensemble
and deterministic guidance has shifted this low further north into
much of the Upper Midwest. Now 80 to 100% of both GEFS and EPS
members have measurable precipitation. The latest LREF has a 30 to
40% chance for greater than 0.25" of rain to fall between Monday
night and Tuesday evening. When looking at WPC cluster analysis.
Each of the four clusters shows this low coming out of the Rockies
and into the Upper Midwest, then getting absorbed into the parent
longwave trough. The main differences, based on ensembles, is
location and strength of this low. Despite this system occurring at
night, rain is the likely precipitation type with temperatures
mostly in the mid 30s to low 40s. After Tuesday, with northwest flow
in place through the rest of the week, we could see some flurries on
Wednesday and Thursday. In addition, with the pressure gradient
appearing the way it is, could see some breezy conditions both days
with gusts up to 25 mph.

Once this low moves through, colder and drier air follows the
longwave trough as it dips down into the northern CONUS.
Temperatures at 850mb are currently ranging between -8 and -12C for
the second half of next week. While both ensemble and deterministic
guidance agrees that colder air moves down next week, the EPS and
ECMWF are slightly warmer than the GFS and GEFS, indicating that the
GEFS solution is deeper compared to the EPS solutions. Regardless,
temperatures for Wednesday compared to Tuesday will be 10 to 15
degrees cooler with highs in the low to mid 30s. By Thanksgiving and
heading into the weekend, we could see highs in the 20s to low 30s.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1112 PM CST Thu Nov 20 2025

VFR expected through the 21.06Z TAF period.

High confidence for subsequent aviation impacts reaching the
Upper Mississippi River Valley Sunday night.

&&

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

&&

$$

DISCUSSION...Cecava
AVIATION...JAR