La Crosse, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

585
FXUS63 KARX 111757
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1257 PM CDT Sat Apr 11 2026

.KEY MESSAGES...

- Much warmer temperatures beginning on Sunday and into the upcoming
  work week with highs in the 70s and 80s for many. Overnight lows may
  challenge daily warm low records with lows in the 50s to lower 60s
  on Monday and Tuesday.

- Active pattern from today through Tuesday with periods of
  showers and storms. There is some potential for severe storms
  during this period with Monday and Tuesday currently posing
  the greatest risk.

- Showers and storms chances persist through the end of the upcoming
  work week.

&&

.DISCUSSION...
Issued at 1233 PM CDT Sat Apr 11 2026

Rest of Today - Sunday: Trending Warmer with Showers and Storms

An axis of showers and embedded storms will move through the region
today and into the evening/overnight hours as a weak axis of 700mb
warm advection moves through the region. Overall this is within a
broader area of upper-level ridging which will allow our
temperatures to steadily trend warmer over the weekend. The
environment for any storms that develop in the area this evening
and into the overnight is fairly unimpressive from a severe
perspective as any convection will be forming atop a profound
warm nose with MUCAPE values in the RAP of only around 500-1000
J/kg, mainly west of the Mississippi River. However with mid-
level lapse rates approaching 7 C/km near I-35, would not rule
out some small hail with the stronger updrafts.

As we head into Sunday, noticeably warmer temperatures will be on
tap with southerly surface flow ushering in a much warmer and
moisture rich airmass. As a result, the NBM inter-quartile range for
highs on Sunday ranges anywhere from the lower 70s to around 80. As
this occurs, this warm airmass pushes far to the north with much of
ensemble guidance bringing highs near the 70 degree mark all the way
up to Lake Superior! However, as we head into the evening and
overnight, an enhancing axis of 850mb moisture transport will push
north on the nose of a increasing nocturnal low-level jet. As this
moisture transport axis pushes north not only will it be an
instigating mechanism for showers and storms but will bring some
fairly respectable instability (1000-1500 J/kg of MUCAPE) north with
it across portions of southeast MN and into north-central WI.
Large hail would appear to be the primary hazard still in this
environment with mid-level lapse rates of around 7 C/km, however
could see some damaging wind gusts with decent DCAPE in the RAP
to around 1000 J/kg in the aforementioned region with robust
dry air entrainment possible with any convection that gets
going. Also cannot rule out a weak tornado in north-central WI
as this low-level jet interacts with the surface boundary
overnight, however this would seem pretty unlikely given the
lack of deep-layer shear. Overall though with relatively weak
flow in the mid-levels, this would not favor very organized
convection so this would likely keep the severe threat more
localized in nature.

Monday - Tuesday: Severe Potential Both Monday & Tuesday

The severe potential ramps up slightly into Monday and Tuesday
as we enter a fairly progressive synoptic pattern with various
shortwave perturbations and surface low pressure features that
push northwest of the local area. As we head into Monday the
warm airmass that we were pushed into on Sunday remains with
highs likely yet again reaching into the 70s and 80s.
Additionally, with dewpoints reaching into the 50s and lower 60s
on Monday morning, morning lows on Monday may only be in the
50s to lower 60s as well. These higher dewpoints as a result of
Sunday night`s moisture advection will lay the groundwork for
some severe potential as temperatures heat into the afternoon
with increasing instability. As we head into the evening, a
surface low will pass northwest of the local area dragging the
warm front northward with a sfc boundary draped to its south. As
a result, could see a first round of convective initiation
during the late afternoon as the warm front pushes northward
through the local area, primarily near and north of I-90. In
this environment, soundings in the RAP note fairly robust
capping in the warm sector which would mitigate a tornado
threat, however with fairly robust instability (around 2000 J/kg
in the NAM) atop the warm nose and mid- level lapse rates
approaching 8 C/km, would think that there would be a fairly
robust hail threat with any convection that gets going during
this period.

Now things get a bit more challenging later into the evening as the
surface low pulls northward and swings the aforementioned sfc
boundary east into the local area late Monday evening and into
the overnight. As this occurs, there is some tendency in the
deterministic models NAM/GFS/RRFS for thermodynamic profiles to
gravitate to more surface-based with this being coupled with an
increasing low-level jet resulting in 0-1km SRH values sharply
increasing to around 200-300 m2/s2. As a result, if any
convection can get going along this boundary into the overnight,
this may pose a tornado risk IF surface based convection can be
realized. Still not exactly clear if the warm nose can be
cooled enough to allow for surface based storms though. In any
case, this period is probably the lowest confidence period for
severe potential at this juncture in the forecast process.

The active pattern persists into Tuesday though with additional
severe potential on the table. Overall confidence in seeing strong
to severe storms in the warm sector is higher for Tuesday given the
general agreement for more surface based instability in the GFS/NAM.
However, the key question is exactly how far north this warm sector
reaches into the local area during the afternoon hours. Generally
speaking, the GEFS/GEPS has fairly high probabilities (50-90%
chance) for over 1000 J/kg of SBCAPE for areas near and south of I-
90 on Tuesday afternoon so would think that areas generally near and
south of I-90 would be most likely to have ample surface-based
instability for convection with the highest confidence being in
portions of southwest WI and northeast IA. Decent hodograph
elongation would favor supercells in this environment with all
hazards being in play.

In addition to the severe potential, will have to see where each
round of storms lines up as there is some heavy rain potential as
well given that we may see several rounds of showers storms through
Tuesday. Overall, the NBM 72-hr QPF inter-quartile spread has a
general 1-2" of rainfall across the area from Sunday through
Tuesday. However, the 90th percentile has spots approaching 3"+,
likely where storms repeat over the same locations. As a result,
does not currently appear to be a widespread flooding setup but
localized spots that receive higher amounts may see some rises on
area rivers.

In summary, strong to severe storms possible late Monday afternoon
and continuing into the overnight with large hail and a conditional
tornado threat later into the evening. On Tuesday, confidence
is higher for storms that develop to be strong to severe but
questions remain on exactly how far north into the local area
the threat extends with all hazards possible. In any case, will
need to watch to see where storms track as storms that frequent
the same areas may result in rises on rivers in those respective
basins.

Wednesday - Friday: Shower and Storm Chances Persist

As we head into the middle of the upcoming work week, rain chances
likely persist however with the higher probabilities (0-30%
locally) for dewpoints over 55 degrees remaining south of the
local area on Wednesday and Thursday, think that this should
lessen the severe weather potential. Additionally, probabilities
for rainfall amounts over 0.25" are not overly high (20-50%) on
Wednesday and Thursday. The overall pattern becomes a bit more
active into Friday though as a secondary trough out west begins
to eject eastward towards the region. As a result, Friday could
see an additional round of storms with joint probabilities for
500 J/kg of SBCAPE and 30 kts of bulk shear in the grand
ensemble (GEFS/EC/Canadian ensemble) increasing to around 30 to
50 percent. Regardless of any severe potential, the NBM has
decent probabilities (40-50%) for rainfall amounts of over 0.5"
on Friday as well.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1254 PM CDT Sat Apr 11 2026

Increasing moisture should lead to both periodic showers through
the period and an eventual reduction in ceilings to MVFR and
even IFR over the next 6-12 hours. Uncertainty surrounds exact
timing of showers and if any thunderstorms will occur. Latest
trends suggest TS will struggle mightily to develop until late
tonight when a low level jet ramps up - have handled the
possiblity with targeted PROB30 groups rather than prevailing
TS. This jet should also lead to low level turbulence but,
without much change in direction over the lowest 2 kft, have
left LLWS mentions out of the TAF.

&&

.CLIMATE...
Issued at 1233 PM CDT Sat Apr 11 2026

Potential Record Warmth Monday & Tuesday (Record/Forecast):

April 13th           High Temp           Warm Low
-----------          --------            -------
Rochester, MN     83 (2023) / 75       59 (1941) / 57
La Crosse, WI     85 (2023) / 78       63 (1941) / 59

April 14th
----------
Rochester, MN     87 (2003) / 76       56 (1976) / 56
La Crosse, WI     90 (2003) / 78       60 (1883) / 58

&&

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

&&

$$

DISCUSSION...Naylor
AVIATION...Ferguson
CLIMATE...Naylor/JAR