La Crosse, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

045
FXUS63 KARX 071744
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1244 PM CDT Sat Jun 7 2025

.KEY MESSAGES...

- Precipitation chances today, Sunday, and Monday.

- Primary area of precipitation west of the Mississippi River
  Valley today and north of Interstate 94 through Sunday.

- Slightly cool weekend warming through the new week.

&&

.DISCUSSION...
Issued at 351 AM CDT Sat Jun 7 2025

Early morning GOES water vapor loops and derived upper level
winds depict a closed area of cyclonic flow quickly progressing east
across the Central Plains, an upstream trough digging southeast over
the Canadian Rockies tied to a stronger extratropical cyclone just
south of 60 degrees north, and diffluent flow over the forecast area.

Precipitation Chances Today:

The quickly progressing synoptic-alpha scale cyclonic flow over the
Central Plains is providing meager return flow with a low level
theta e lobe poking into the Northern Plains (POES). Increased winds
(GOES) upstream of the low will draw its progression and
accompanying forcing south of the local forecast area today.
More influentially, a stronger solution in the upstream high
pressure has advected the drier air farther west into Wisconsin.
The combination of these forcings has narrowed (dProg/dt
NBM/HREF) the corridor of higher precipitation chances and
overall QPF amounts today west of the Mississippi River Valley.

Higher instability will also remain tied to the more moist air
to the west. However high resolution model soundings
(RAP/Fv3/HRRR/ARW) do exhibit /some/ transient instability
keeping thunderstorms possible. While instability will graze our
western counties, decreased low level lapse rates concurrent
with positive surface vorticity advection limit local non-
supercell tornado potential.

Precipitation Chances Overnight Through Sunday:

As high resolution models start to capture the picture through
Sunday, initial suggestions surround higher precipitation
amounts when the aforementioned synoptic trough traversing the
Upper Mississippi River Valley. While moisture seems relatively
consistent between the last two runs, a more southern solution
to the synoptic low has pushed better forcing through the area.
This is evident in NBM probabilities for 0.5" of QPF in 24 hours
reaching 50% as far southwest as Trempealeau to Jackson
counties in western Wisconsin. However LREF models aren`t /as/
enthusiastic with a consistent solution... slightly farther
north with a sharp gradient in confidence locally. Given the
better forcing to the north, higher amounts expected along and
north of Interstate 94. Both the NBM and HREF show a 25th to
75th percentile from 0.25" to 0.6" with a mean near 0.5" through
Sunday.

Precipitation Chances Monday:

After the attendant trough passes through the main low makes its
appearance for the start of the week. Overall precipitation
amounts will be limited as the initial trough and attendant
frontal boundary removes the better moisture.

Cool Weekend Warming Through Next Week:

Given the continental canadian airmass progressing through the
region this weekend into early next week, temperatures will remain a
few degrees below normal with daytime highs in the 60s and 70s
through Tuesday. Eventually a broad area of building upper level
heights progresses east across the CONUS, according to LREF
probabilities in 500dam heights, ushering in a warm spell through
the end of next week. Both the EPS and GEFS have been warming over
the last couple of runes with the EPS remaining a slightly warmer
solution. The longer forecast area leaves much to be ironed out
although ECMWF EFI/SOT depicts as single pixel bullseye of 0.74 over
the forecast area.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1244 PM CDT Sat Jun 7 2025

VFR conditions are expected through the remainder of the daytime
hours today with bkn to ovc cigs and some passing showers this
afternoon. However, the probability for category reductions from
these showers is low (10-20% chance). As we head into the overnight,
a line of showers and storms will move into the region and persist
into the early morning hours. Overall probabilities for MVFR cigs in
the 07.12z HREF are fairly high (60-80% chance) during this
period, but confidence remains lower on exact timing. As a
result, have kept any MVFR mention to the -TSRA tempo group for
now. Winds will remain from the south at around 5-10 kts with
occasional gusts as high as 20 kts west of the Mississippi
River. Winds will shift to west/northwesterly tomorrow morning
behind the aforementioned line of showers and storms.

&&

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

&&

$$

DISCUSSION...JAR
AVIATION...Naylor